ALBERT

Description: Nell’ambito del progetto EDISECUR, finanziato della regione Lazio, è stato sviluppato un prototipo di telesensore infrasonico, TIS, a tracciamento di speckle per la misura della velocità angolare, delle frequenze fondamentali e delle armoniche di una superficie sottoposta a oscillazioni. Il TIS si presta particolarmente per il rilevamento e il monitoraggio nel tempo degli edifici, ponti e altri manufatti. Conoscere lo stato vibrazionale di queste strutture può essere d’interesse sia per la loro caratterizzazione dinamica che per la sicurezza. Questo prototipo, sufficientemente compatto, si presta a una misura immediata della velocità angolare e, con semplici operazioni, si possono dedurre spostamenti e accelerazioni angolari. Dalle grandezze angolari e dalla conoscenza geometrica della superficie, tramite alcuni schemi ed esempi, si mostra come sia possibile determinare anche altri parametri cinematici lineari. Il telesensore può essere impiegato nelle misure delle vibrazioni di superfici a lunga distanza di varia natura, anche laddove non fosse possibile accedere per eseguire una misura diretta. Lo strumento copre un campo di frequenze fino alle decine di Hz, ha una sensibilità e una dinamica tale da rilevare le vibrazioni indotte dal rumore industriale, dal traffico, dal vento e altro. Questo lavoro è principalmente rivolto alle applicazioni del TIS nel rilevamento delle vibrazioni delle strutture ed è in questo ambito che vengono spiegate le modalità, i limiti e i vantaggi del suo impiego insieme agli errori insiti nella tecnica di misura. Dato che il TIS misura un movimento relativo tra lo stesso strumento e la superficiebersaglio, sono stati valutati gli errori delle vibrazioni dovute alla microsismicità e altre cause ambientali. Vengono infine riportati due preliminari esempi di misura su una struttura edile.

Description: Regione Lazio, progetto EDISECUR

Description: Published

Description: 1-36

Description: 7TM.Sviluppo e Trasferimento Tecnologico

Description: JCR Journal

Description: L’Istituto Nazionale di Geofisica e Vulcanologia (INGV) riceve, nella Sala di Sorveglianza Sismica e Centro Allerta Tsunami di Roma, i segnali in tempo reale da centinaia di stazioni sismiche distribuite sul territorio nazionale. Entro due minuti dall’occorrenza di un qualsiasi terremoto, appositi sistemi automatici forniscono una prima valutazione dei parametri ipocentrali. Due sismologi, sempre presenti nella sala operativa della sede centrale, controllano le informazioni ottenute e, per i terremoti sopra una determinata soglia di magnitudo (ML ≥ 2.5), comunicano alla Sala Situazione Italia della Protezione Civile i dati elaborati, in media in circa 12 minuti (massimo entro 30 minuti) [Margheriti et al., 2021]. La valutazione definitiva dei parametri ipocentrali di tutti i terremoti, dai più grandi avvertiti in vaste aree del territorio ai più piccoli rilevati solo da pochi strumenti, è demandata a un’analisi più accurata svolta in un secondo tempo, ormai da alcuni decenni, da un gruppo di analisti specializzati nell’interpretazione dei segnali sismici. Gli analisti sismologi del Bollettino Sismico Italiano revisionano tutti i dati registrati dalle stazioni della Rete Sismica Nazionale (RSN) dell’INGV e riconoscono la presenza di terremoti attraverso un’analisi diretta delle forme d’onda. In tal modo l’analista rileva il tempo d’arrivo delle onde sismiche ai vari sensori e valuta l’ampiezza delle oscillazioni e la direzione del moto del suolo; questi parametri, utilizzati da apposite procedure di calcolo, consentono di localizzare ogni terremoto e di valutare la magnitudo associata. Le informazioni così ottenute confluiscono nel database che l’INGV gestisce e che mette a disposizione della comunità1. Questa pubblicazione ha come scopo quello di far conoscere un prodotto dell’Istituto Nazionale di Geofisica e Vulcanologia, Il Bollettino Sismico Italiano (BSI), con particolare riferimento all’anno 2015. Saranno delineate le principali caratteristiche della sismicità naturale e quella di origine antropica registrata in Italia nel corso dell’anno esaminato.

Description: Published

Description: 1-48

Description: 4IT. Banche dati

Description: JCR Journal

Description: This study represents the first attempt to combine the geomorphological characteristics of the island of Ustica with the human settlements that have been established during prehistory, with the purpose of reconstructing the interactions between communities and the natural environment from the Neolithic to the Middle Bronze Age (6th - 1st millennia B.C.). Ustica is a small island in the Southern Tyrrhenian Sea, visible but far (~55 km) from the northern coast of western Sicily. Its rugged volcanic nature, remodeled and enriched by the sea, offered to the first colonizers a wide repertoire of opportunities and challenges. This island can be treated as an ideal “laboratory” to understand how settlers, taking their first steps towards the foundation of organized communities, were able to seize opportunities or succumb to obstacles. The review of archaeological research until now carried out in Ustica, integrated with geomorphological data and other biogeographical indicators, offers a picture of the prehistory of Ustica in which human presence is continuous and distributed in various sites of the island characterized by different physiographic characteristics. There are phases dominated by the choice of naturally protected sites and phases in which settlements expands on open land, suitable for agricultural use. Where the archaeological evidence is scarce, the geomorphological peculiarities allow us to decipher the vocations and characters of a human settlement. The study leads to an open question: in the Middle Bronze Age, after about five thousand years of uninterrupted habitation of Ustica, which factors, geological, social, or other, induced the early communities to abandon the island, without returning there for about eight centuries, until the Hellenistic-Roman age?

Description: Published

Description: VO550

Description: 6A. Geochimica per l'ambiente e geologia medica

Description: JCR Journal

Description: This work sets out to identify a state-of-the-art system to be used for the calibration of seismic sensors. The aim is to acquire such a system within the framework of the PON ARS01 00926 EWAS (an Early Warning System for cultural heritage) project, which seeks to develop new technologies for the protection, conservation and safety of cultural heritage and envisages creating a newly developed seismic monitoring system. This system will exploit the ETL3D/5s-H hybrid sensors, resulting from the integration of a precision accelerometer within the ETL3D/5s velocimeter [Fertitta et al., 2020]. The new calibration system, already acquired and being installed, can be used by the EWAS project partners (including the National Institute of Geophysics and Volcanology and the Kore University of Enna), to calibrate the ETL3D/5s-H sensors, and by external organisations to calibrate or gauge other seismic sensors, thus providing a useful service to the scientific community and supporting industrial activities. This paper presents the method used and the activities undertaken to define the technical specifications of the calibration system. A feasibility study of an electromechanical vibrating table and the testing of two electrodynamic calibration systems were carried out. One of the electrodynamic systems is the CS18P (Calibration System for Seismic Sensors) produced by the German firm SPEKTRA. The CS18P comprises two vibrating tables, one horizontal and one vertical, which, thanks to their fluid-dynamic suspension, eliminate the sliding and rolling friction associated with the movement of the moving part with respect to the fixed part. A hardware and software system monitors and controls the motion in real time, analyses the data and automatically processes a predefined set of measurements. In the light of the technical specifications and experimental results, the CS18P represents the ideal solution for the aims of the EWAS project and also in view of the possible future uses of the calibration system.

Description: Published

Description: 1-38

Description: 2IT. Laboratori analitici e sperimentali

Description: JCR Journal

Description: In recent years, new approaches for developing earthquake rupture forecasts (ERFs) have been proposed to be used as an input for probabilistic seismic hazard assessment (PSHA). Zone- based approaches with seismicity rates derived from earthquake catalogs are commonly used in many countries as the standard for national seismic hazard models. In Italy, a single zone- based ERF is currently the basis for the official seismic hazard model. In this contribution, we present eleven new ERFs, including five zone-based, two smoothed seismicity-based, two fault- based, and two geodetic-based, used for a new PSH model in Italy. The ERFs were tested against observed seismicity and were subject to an elicitation procedure by a panel of PSHA experts to verify the scientific robustness and consistency of the forecasts with respect to the observations. Tests and elicitation were finalized to weight the ERFs. The results show a good response to the new inputs to observed seismicity in the last few centuries. The entire approach was a first attempt to build a community-based set of ERFs for an Italian PSHA model. The project involved a large number of seismic hazard practitioners, with their knowledge and experience, and the development of different models to capture and explore a large range of epistemic uncertainties in building ERFs, and represents an important step forward for the new national seismic hazard model.

Description: Published

Description: SE220

Description: 6T. Studi di pericolosità sismica e da maremoto

Description: JCR Journal

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Malige, F., Patris, J., Buchan, S. J., Stafford, K. M., Shabangu, F., Findlay, K., Hucke-Gaete, R., Neira, S., Clark, C. W., & Glotin, H. Inter-annual decrease in pulse rate and peak frequency of Southeast Pacific blue whale song types. Scientific Reports, 10(1), (2020): 8121, doi:10.1038/s41598-020-64613-0.

Description: A decrease in the frequency of two southeast Pacific blue whale song types was examined over decades, using acoustic data from several different sources in the eastern Pacific Ocean ranging between the Equator and Chilean Patagonia. The pulse rate of the song units as well as their peak frequency were measured using two different methods (summed auto-correlation and Fourier transform). The sources of error associated with each measurement were assessed. There was a linear decline in both parameters for the more common song type (southeast Pacific song type n.2) between 1997 to 2017. An abbreviated analysis, also showed a frequency decline in the scarcer southeast Pacific song type n.1 between 1970 to 2014, revealing that both song types are declining at similar rates. We discussed the use of measuring both pulse rate and peak frequency to examine the frequency decline. Finally, a comparison of the rates of frequency decline with other song types reported in the literature and a discussion on the reasons of the frequency shift are presented.

Description: The authors thank the help of Explorasub diving center (Chile), Agrupación turística Chañaral de Aceituno (Chile), ONG Eutropia (Chile), Valparaiso university (Chile), the international institutions and research programs CTBTO, IWC, BRILAM STIC AmSud 17-STIC-01. S.J.B. thanks support from the Center for Oceanographic Research COPAS Sur-Austral, CONICYT PIA PFB31, Biology Department of Woods Hole Oceanographic Institution, the Office of Naval Research Global (awards N62909-16-2214 and N00014-17-2606), and a grant to the Centro de Estudios Avanzados en Zonas Ãridas (CEAZA) “Programa Regional CONICYT R16A10003”. We thank SABIOD MI CNRS, EADM MaDICS CNRS and ANR-18-CE40-0014 SMILES supporting this research. We are grateful to colleagues at DCLDE 2018 and SOLAMAC 2018 conferences for useful comments on the preliminary version of this work. In this work we used only the free and open-source softwares Latex, Audacity and OCTAVE.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ward, N. D., Megonigal, J. P., Bond-Lamberty, B., Bailey, V. L., Butman, D., Canuel, E. A., Diefenderfer, H., Ganju, N. K., Goni, M. A., Graham, E. B., Hopkinson, C. S., Khangaonkar, T., Langley, J. A., McDowell, N. G., Myers-Pigg, A. N., Neumann, R. B., Osburn, C. L., Price, R. M., Rowland, J., Sengupta, A., Simard, M., Thornton, P. E., Tzortziou, M., Vargas, R., Weisenhorn, P. B., & Windham-Myers, L. Representing the function and sensitivity of coastal interfaces in earth system models. Nature Communications, 11(1), (2020): 2458, doi:10.1038/s41467-020-16236-2.

Description: Between the land and ocean, diverse coastal ecosystems transform, store, and transport material. Across these interfaces, the dynamic exchange of energy and matter is driven by hydrological and hydrodynamic processes such as river and groundwater discharge, tides, waves, and storms. These dynamics regulate ecosystem functions and Earth’s climate, yet global models lack representation of coastal processes and related feedbacks, impeding their predictions of coastal and global responses to change. Here, we assess existing coastal monitoring networks and regional models, existing challenges in these efforts, and recommend a path towards development of global models that more robustly reflect the coastal interface.

Description: Funding for this work was provided by Pacific Northwest National Laboratory (PNNL) Laboratory Directed Research & Development (LDRD) as part of the Predicting Ecosystem Resilience through Multiscale Integrative Science (PREMIS) Initiative. PNNL is operated by Battelle for the U.S. Department of Energy under Contract DE-AC05-76RL01830. Additional support to J.P.M. was provided by the NSF-LTREB program (DEB-0950080, DEB-1457100, DEB-1557009), DOE-TES Program (DE-SC0008339), and the Smithsonian Institution. This manuscript was motivated by discussions held by co-authors during a three-day workshop at PNNL in Richland, WA: The System for Terrestrial Aquatic Research (STAR) Workshop: Terrestrial-Aquatic Research in Coastal Systems. The authors thank PNNL artist Nathan Johnson for preparing the figures in this manuscript and Terry Clark, Dr. Charlette Geffen, and Dr. Nancy Hess for their aid in organizing the STAR workshop. The authors thank all workshop participants not listed as authors for their valuable insight: Lihini Aluwihare (contributed to biogeochemistry discussions and development of concept for Fig. 3), Gautam Bisht (contributed to modeling discussion), Emmett Duffy (contributed to observational network discussions), Yilin Fang (contributed to modeling discussion), Jeremy Jones (contributed to biogeochemistry discussions), Roser Matamala (contributed to biogeochemistry discussions), James Morris (contributed to biogeochemistry discussions), Robert Twilley (contributed to biogeochemistry discussions), and Jesse Vance (contributed to observational network discussions). A full report on the workshop discussions can be found at https://www.pnnl.gov/publications/star-workshop-terrestrial-aquatic-research-coastal-systems.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Liang, Y., Lo, M., Lan, C., Seo, H., Ummenhofer, C. C., Yeager, S., Wu, R., & Steffen, J. D. Amplified seasonal cycle in hydroclimate over the Amazon river basin and its plume region. Nature Communications, 11(1), (2020): 4390, doi:10.1038/s41467-020-18187-0.

Description: The Amazon river basin receives ~2000 mm of precipitation annually and contributes ~17% of global river freshwater input to the oceans; its hydroclimatic variations can exert profound impacts on the marine ecosystem in the Amazon plume region (APR) and have potential far-reaching influences on hydroclimate over the tropical Atlantic. Here, we show that an amplified seasonal cycle of Amazonia precipitation, represented by the annual difference between maximum and minimum values, during the period 1979–2018, leads to enhanced seasonalities in both Amazon river discharge and APR ocean salinity. An atmospheric moisture budget analysis shows that these enhanced seasonal cycles are associated with similar amplifications in the atmospheric vertical and horizontal moisture advections. Hierarchical sensitivity experiments using global climate models quantify the relationships of these enhanced seasonalities. The results suggest that an intensified hydroclimatological cycle may develop in the Amazonia atmosphere-land-ocean coupled system, favouring more extreme terrestrial and marine conditions.

Description: M.-H.L., C.-W.L., and R.-J.W. are supported by the Ministry of Science and Technology in Taiwan under grant 106-2111-M-002-010-MY4. H.S. and J.D.S. are grateful for support from NOAA NA19OAR4310376 and NA17OAR4310255. C.C.U. acknowledges support from the U.S. National Science Foundation under grant OCE-1663704. The National Center for Atmospheric Research (NCAR) is a major facility sponsored by the US National Science Foundation (NSF) under Cooperative Agreement No. 1852977. We thank Dr. Young-Oh Kwon at Woods Hole Oceanographic Institution and Dr. Who Kim at NCAR for discussions about the ocean model experiment design. We thank Dr. Mehnaz Rashid at National Taiwan University and Wen-Yin Wu at the University of Texas at Austin in helping generate the high-resolution Amazon river mask. We also thank Dr. Gael Forget at Massachusetts Institue of Technology for comments on using ECCO and other ocean-state estimate products.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 33(9), (2020): 3845-3862, doi:10.1175/JCLI-D-19-0215.1.

Description: The latitudinal structure of the Atlantic meridional overturning circulation (AMOC) variability in the North Atlantic is investigated using numerical results from three ocean circulation simulations over the past four to five decades. We show that AMOC variability south of the Labrador Sea (53°N) to 25°N can be decomposed into a latitudinally coherent component and a gyre-opposing component. The latitudinally coherent component contains both decadal and interannual variabilities. The coherent decadal AMOC variability originates in the subpolar region and is reflected by the zonal density gradient in that basin. It is further shown to be linked to persistent North Atlantic Oscillation (NAO) conditions in all three models. The interannual AMOC variability contained in the latitudinally coherent component is shown to be driven by westerlies in the transition region between the subpolar and the subtropical gyre (40°–50°N), through significant responses in Ekman transport. Finally, the gyre-opposing component principally varies on interannual time scales and responds to local wind variability related to the annual NAO. The contribution of these components to the total AMOC variability is latitude-dependent: 1) in the subpolar region, all models show that the latitudinally coherent component dominates AMOC variability on interannual to decadal time scales, with little contribution from the gyre-opposing component, and 2) in the subtropical region, the gyre-opposing component explains a majority of the interannual AMOC variability in two models, while in the other model, the contributions from the coherent and the gyre-opposing components are comparable. These results provide a quantitative decomposition of AMOC variability across latitudes and shed light on the linkage between different AMOC variability components and atmospheric forcing mechanisms.

Description: The authors gratefully acknowledge support from the Physical Oceanography Program of the U.S. National Science Foundation (Awards OCE-1756143 and OCE-1537136) and the Climate Program Office of the National Oceanic and Atmospheric Administration (Award NA15OAR4310088). Gratitude is extended to Claus Böning and Arne Biastoch who shared ORCA025 output. S. Zou thanks F. Li, M. Buckley, and L. Li for helpful discussions. We also thank three anonymous reviewers for helpful suggestions.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gravinese, P. M., Page, H. N., Butler, C. B., Spadaro, A. J., Hewett, C., Considine, M., Lankes, D., & Fisher, S. Ocean acidification disrupts the orientation of postlarval Caribbean spiny lobsters. Scientific Reports, 10(1), (2020): 18092, doi:10.1038/s41598-020-75021-9.

Description: Anthropogenic inputs into coastal ecosystems are causing more frequent environmental fluctuations and reducing seawater pH. One such ecosystem is Florida Bay, an important nursery for the Caribbean spiny lobster, Panulirus argus. Although adult crustaceans are often resilient to reduced seawater pH, earlier ontogenetic stages can be physiologically limited in their tolerance to ocean acidification on shorter time scales. We used a Y-maze chamber to test whether reduced-pH seawater altered the orientation of spiny lobster pueruli toward chemical cues produced by Laurencia spp. macroalgae, a known settlement cue for the species. We tested the hypothesis that pueruli conditioned in reduced-pH seawater would be less responsive to Laurencia spp. chemical cues than pueruli in ambient-pH seawater by comparing the proportion of individuals that moved to the cue side of the chamber with the proportion that moved to the side with no cue. We also recorded the amount of time (sec) before a response was observed. Pueruli conditioned in reduced-pH seawater were less responsive and failed to select the Laurencia cue. Our results suggest that episodic acidification of coastal waters might limit the ability of pueruli to locate settlement habitats, increasing postsettlement mortality.

Description: We thank the Steinwachs Family Foundation, which provided funding that supported Gravinese’s postdoctoral fellowship at Mote Marine Laboratory and Aquarium. We also acknowledge the partial support provided by the St. Petersburg College Titan Achievement minigrant program. Page was supported by a Mote Marine Laboratory and Aquarium Postdoctoral Research Fellowship. Postlarval spiny lobsters were collected with a state-issued Special Activity License (SAL-17-1868G-SR). We also thank those who helped with animal collection throughout this work including in-kind support provided by E. Muller and the Mote CAOS facility, as well as E. Bartels and C. Walter of the Coral Reef Monitoring and Assessment Program at Mote Marine Laboratory and Aquarium, as well as other field personnel including: L. Toth, S. Perry, T. Parker, A. Fine, L. Humphrey, and many undergraduate interns. We also thank L. Toth, E. Ross, B. Sharp, C. Crowley, J. Butler, and B. Crowder for editorial comments.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Huang, J., Pickart, R. S., Huang, R. X., Lin, P., Brakstad, A., & Xu, F. Sources and upstream pathways of the densest overflow water in the Nordic Seas. Nature Communications, 11(1), (2020): 5389, doi:10.1038/s41467-020-19050-y.

Description: Overflow water from the Nordic Seas comprises the deepest limb of the Atlantic Meridional Overturning Circulation, yet questions remain as to where it is ventilated and how it reaches the Greenland-Scotland Ridge. Here we use historical hydrographic data from 2005-2015, together with satellite altimeter data, to elucidate the source regions of the Denmark Strait and Faroe Bank Channel overflows and the pathways feeding these respective sills. A recently-developed metric is used to calculate how similar two water parcels are, based on potential density and potential spicity. This reveals that the interior of the Greenland Sea gyre is the primary wintertime source of the densest portion of both overflows. After subducting, the water progresses southward along several ridge systems towards the Greenland-Scotland Ridge. Kinematic evidence supports the inferred pathways. Extending the calculation back to the 1980s reveals that the ventilation occurred previously along the periphery of the Greenland Sea gyre.

Description: Funding for the study was provided by the US National Science Foundation under grants OCE-1558742 (J.H., R.P.) and OCE-1259618 (P.L.); the Bergen Research Foundation under grant BFS2016REK01 (A.B.); and the National Natural Science Foundation of China No. 41576018 (F.X.) and 41606020 (F.X.).

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Colin, S. P., Costello, J. H., Sutherland, K. R., Gemmell, B. J., Dabiri, J. O., & Du Clos, K. T. The role of suction thrust in the metachronal paddles of swimming invertebrates. Scientific Reports, 10(1), (2020): 17790, doi:10.1038/s41598-020-74745-y.

Description: An abundance of swimming animals have converged upon a common swimming strategy using multiple propulsors coordinated as metachronal waves. The shared kinematics suggest that even morphologically and systematically diverse animals use similar fluid dynamic relationships to generate swimming thrust. We quantified the kinematics and hydrodynamics of a diverse group of small swimming animals who use multiple propulsors, e.g. limbs or ctenes, which move with antiplectic metachronal waves to generate thrust. Here we show that even at these relatively small scales the bending movements of limbs and ctenes conform to the patterns observed for much larger swimming animals. We show that, like other swimming animals, the propulsors of these metachronal swimmers rely on generating negative pressure along their surfaces to generate forward thrust (i.e., suction thrust). Relying on negative pressure, as opposed to high pushing pressure, facilitates metachronal waves and enables these swimmers to exploit readily produced hydrodynamic structures. Understanding the role of negative pressure fields in metachronal swimmers may provide clues about the hydrodynamic traits shared by swimming and flying animals.

Description: This work was funded by National Science Foundation (NSF OCE 1829913 to SPC), the Alfred P. Sloan Foundation (to BJG) and the Gordon and Betty Moore Foundation (8835 to KRS). The work was also supported by the Roger Williams Foundation to Promote Scholarship and Teaching.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Hahn, L. C., Storelvmo, T., Hofer, S., Parfitt, R., & Ummenhofer, C. C. Importance of Orography for Greenland cloud and melt response to atmospheric blocking. Journal of Climate, 33(10), (2020): 4187-4206, doi:10.1175/JCLI-D-19-0527.1.

Description: More frequent high pressure conditions associated with atmospheric blocking episodes over Greenland in recent decades have been suggested to enhance melt through large-scale subsidence and cloud dissipation, which allows more solar radiation to reach the ice sheet surface. Here we investigate mechanisms linking high pressure circulation anomalies to Greenland cloud changes and resulting cloud radiative effects, with a focus on the previously neglected role of topography. Using reanalysis and satellite data in addition to a regional climate model, we show that anticyclonic circulation anomalies over Greenland during recent extreme blocking summers produce cloud changes dependent on orographic lift and descent. The resulting increased cloud cover over northern Greenland promotes surface longwave warming, while reduced cloud cover in southern and marginal Greenland favors surface shortwave warming. Comparison with an idealized model simulation with flattened topography reveals that orographic effects were necessary to produce area-averaged decreasing cloud cover since the mid-1990s and the extreme melt observed in the summer of 2012. This demonstrates a key role for Greenland topography in mediating the cloud and melt response to large-scale circulation variability. These results suggest that future melt will depend on the pattern of circulation anomalies as well as the shape of the Greenland Ice Sheet.

Description: This research was supported by the Woods Hole Oceanographic Institution Summer Student Fellow program, by the U.S. National Science Foundation under AGS-1355339 to C.C.U., and by the European Research Council through Grant 758005.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Wiechmann, A. F., Martin, T. A., & Horb, M. E. CRISPR/Cas9 mediated mutation of the mtnr1a melatonin receptor gene causes rod photoreceptor degeneration in developing Xenopus tropicalis. Scientific Reports, 10(1), (2020): 13757, doi:10.1038/s41598-020-70735-2.

Description: Nighttime surges in melatonin levels activate melatonin receptors, which synchronize cellular activities with the natural light/dark cycle. Melatonin receptors are expressed in several cell types in the retina, including the photon-sensitive rods and cones. Previous studies suggest that long-term photoreceptor survival and retinal health is in part reliant on melatonin orchestration of circadian homeostatic activities. This scenario would accordingly envisage that disruption of melatonin receptor signaling is detrimental to photoreceptor health. Using in vivo CRISPR/Cas9 genomic editing, we discovered that a small deletion mutation of the Mel1a melatonin receptor (mtnr1a) gene causes a loss of rod photoreceptors in retinas of developing Xenopus tropicalis heterozygous, but not homozygous mutant tadpoles. Cones were relatively spared from degeneration, and the rod loss phenotype was not obvious after metamorphosis. Localization of Mel1a receptor protein appeared to be about the same in wild type and mutant retinas, suggesting that the mutant protein is expressed at some level in mutant retinal cells. The severe impact on early rod photoreceptor viability may signify a previously underestimated critical role in circadian influences on long-term retinal health and preservation of sight. These data offer evidence that disturbance of homeostatic, circadian signaling, conveyed through a mutated melatonin receptor, is incompatible with rod photoreceptor survival.

Description: The National Xenopus Resource (NXR) Genome Editing Workshop conducted at the Marine Biological Laboratory (MBL) contributed to the early development of this project (A.F.W. & M.E.H). We thank Dr. Marcin Wlizla, Sean McNamara, Rosie Falco, and Dr. Will Ratzen of the NXR and MBL for their advice and assistance with the F0 founders. We thank Cynthia Bulmer of the NIH Diabetes CoBRE (P20GM104934) Core Histology Facility at the University of Oklahoma Health Sciences Center (OUHSC) for preparing the histology specimens. We thank Dr. David Sherry of OUHSC for critically reading the initial version of the manuscript and his helpful advice during this study.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Dzwonkowski, B., Coogan, J., Fournier, S., Lockridge, G., Park, K., & Lee, T. Compounding impact of severe weather events fuels marine heatwave in the coastal ocean. Nature Communications, 11(1), (2020): 4623, doi:10.1038/s41467-020-18339-2.

Description: Exposure to extreme events is a major concern in coastal regions where growing human populations and stressed natural ecosystems are at significant risk to such phenomena. However, the complex sequence of processes that transform an event from notable to extreme can be challenging to identify and hence, limit forecast abilities. Here, we show an extreme heat content event (i.e., a marine heatwave) in coastal waters of the northern Gulf of Mexico resulted from compounding effects of a tropical storm followed by an atmospheric heatwave. This newly identified process of generating extreme ocean temperatures occurred prior to landfall of Hurricane Michael during October of 2018 and, as critical contributor to storm intensity, likely contributed to the subsequent extreme hurricane. This pattern of compounding processes will also exacerbate other environmental problems in temperature-sensitive ecosystems (e.g., coral bleaching, hypoxia) and is expected to have expanding impacts under global warming predictions.

Description: This work would not have been possible without the help of the Tech Support Group at the Dauphin Island Sea Lab. A portion of this work was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. This research was made possible by the NOAA RESTORE Science Program (NA17NOS4510101 and NA19NOS4510194) and NOAA NGI NMFS Regional Collaboration Network (18-NGI3-61).

Description: Mobile network routers in seismic and volcanic surveillance

Description: Published

Description: 1-36

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: N/A or not JCR

Description: This special issue of “Annals of Geophysics” concerns the dissemination of knowledge on the prevention of damage mainly due to non-structural elements during earthquakes and its practical application at houses, schools and offices by common citizens, companies and institutions. The seismic capacity of buildings and other civil engineering structures and infrastructures are object of regulations for design and construction, and in some cases also the design, fabrication and mounting of electrical and mechanical equipments. Consequently, even in strong earthquakes many collapses of buildings and infrastructures are avoided. However, with few exceptions, design procedures do not aim at avoiding seismic vibrations from being transferred to the structures, but enable the structures to resist to the effects of those vibrations

Description: European Commission’s Humanitarian Aid and Civil Protection (Grant agreement ECHO/SUB/2015/718655/PREV28)

Description: Published

Description: SE331

Description: 3TM. Comunicazione

Description: JCR Journal

Description: Encouraging property owners and individuals to adopt mitigation measures to improve the resilience of their buildings and equipments to seismic hazard has been a major challenge in many earthquake- prone countries. Few business leaders are aware of the fragility of their supply chains or other critical systems due to earthquake hazard. Bridging the gap between research production and research use is another crucial challenge for the earthquake risk research process. The KnowRISK project outcome is aimed at encouraging the proactive engagement of multi- stakeholders (community at large, schools, business community and local govern-ment groups) undertaking non-structural mitigation measures that will minimize earthquake losses to individuals and communities. Engaging stakeholders, taking into account their needs and inputs to maintain critical and urgent business activities, can contribute to the research findings and ensure that our data collection is thorough and complete. Engagement with stakeholders, during the whole process can lead to improved outcomes and for the development of viable solutions, for business and society, because of stakeholder’s role and influence within the organizations.

Description: European Commission’s Humanitarian Aid and Civil Protection (Grant agreement ECHO/SUB/2015/718655/PREV28)

Description: Published

Description: SE324

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: The focus of this study is the analysis of a cave in Central Italy, the Beatrice Cenci cave, in order topoint out and constrain evidence of possible past earthquakes and of fault activity in the area. Weperformed a survey of seismic related damages within the cave. This included the analysis ofbroken/collapsed speleothems, the recognition of structural collapse, of tilting/growth alteration inthe speleothems, and the mapping of fractures, joints and/or faults. To timely set the occurrence ofthe recognized damage, organic sediments were dated with 14C radiocarbon method. The resultsmerged toward the recognition of two distinct seismic shaking events affecting the caveenvironment, one older than 30 kyr and another around 7 kyr. The deformation observed withinthe cave led us to the hypothesis that the events of damage were possibly linked to the activity ofthe regional tectonic lineament that crosses the cave, i.e., the Liri normal fault. The morphology andthe evolution of the cave appear controlled by the fault zone. These speleoseismological resultsprovided a new contribution on the knowledge of the past activity of the Liri fault and on theearthquake history of this sector of Central Apennines.

Description: INGV

Description: Published

Description: SE435

Description: 2T. Deformazione crostale attiva

Description: JCR Journal

Description: To examine the atmospheric responses to Arctic sea ice variability in the Northern Hemisphere cold season (from October to the following March), this study uses a coordinated set of large-ensemble experiments of nine atmospheric general circulation models (AGCMs) forced with observed daily varying sea ice, sea surface temperature, and radiative forcings prescribed during the 1979–2014 period, together with a parallel set of experiments where Arctic sea ice is substituted by its climatology. The simulations of the former set reproduce the near-surface temperature trends in reanalysis data, with similar amplitude, and their multimodel ensemble mean (MMEM) shows decreasing sea level pressure over much of the polar cap and Eurasia in boreal autumn. The MMEM difference between the two experiments allows isolating the effects of Arctic sea ice loss, which explain a large portion of the Arctic warming trends in the lower troposphere and drive a small but statistically significant weakening of the wintertime Arctic Oscillation. The observed interannual covariability between sea ice extent in the Barents–Kara Seas and lagged atmospheric circulation is distinguished from the effects of confounding factors based on multiple regression, and quantitatively compared to the covariability in MMEMs. The interannual sea ice decline followed by a negative North Atlantic Oscillation–like anomaly found in observations is also seen in the MMEM differences, with consistent spatial structure but much smaller amplitude. This result suggests that the sea ice impacts on trends and interannual atmospheric variability simulated by AGCMs could be underestimated, but caution is needed because internal atmospheric variability may have affected the observed relationship.

Description: Published

Description: 8419–8443

Description: 2A. Fisica dell'alta atmosfera

Description: JCR Journal

Description: Il presente lavoro raccoglie alcune esperienze di Progetti di Alternanza Scuola Lavoro (d’ora in poi ASL) realizzati dall’INGV negli anni scolastici dal 2015 al 2019 e dedicati al rischio sismico, alle scienze polari ed agli strumenti per la divulgazione scientifica. Le esperienze descrivono il lavoro realizzato da un gruppo di ricercatori INGV con competenze in diversi ambiti disciplinari (sismologia, geologia, vulcanologia fisica dell’atmosfera, psicologia) e in alcuni casi le attività sono state svolte in collaborazione con ricercatori di altri enti. Il gruppo di lavoro è composto da ricercatori che da molti anni dedicano parte del loro tempo-lavoro alle attività di divulgazione scientifica, ai progetti educativi, alla didattica della scienza. In una parola a quella che oggi rappresenta, per gli enti di ricerca, la “Terza missione”, ovvero l’insieme di tutte le attività finalizzate a creare una connessione bidirezionale tra il mondo della ricerca e la società. Ciò che ha caratterizzato l’approccio dei ricercatori INGV ai progetti ASL, sia nella fase di progettazione che di realizzazione, è la finalità di consentire agli studenti di vivere un’esperienza reale ed immersiva in un contesto di lavoro. E quindi l’opportunità di sperimentare capacità e abilità che caratterizzano il contesto organizzativo (diritti, doveri, responsabilità, impegni, regole), diversamente dal mondo della scuola. Il secondo aspetto al quale ci si è riferiti nella realizzazione dei progetti è quello di consentire agli studenti di esplorare, in particolare il contesto delle attività lavorative connesse al mondo della ricerca. Da questo punto di vista gli studenti hanno potuto acquisire conoscenze in ambiti tematici specifici, hanno avuto modo di sperimentare metodi e tecniche proprie del mondo della ricerca e di acquisire capacità e abilità trasversali come il lavoro in gruppo. Il contributo è organizzato in tre capitoli in relazione ai temi affrontati nei progetti. Nel primo sono riportate le schede dei tre progetti dedicate al tema Terremoto; nel secondo vengono descritti i due progetti dedicati alla Divulgazione Scientifica e nel terzo un progetto sulle Scienze Polari. Per rendere maggiormente fruibile la lettura, ogni progetto viene descritto attraverso una scheda sintetica che evidenza le caratteristiche principali: titolo, referenti INGV, studenti partecipanti, periodo, descrizione delle attività, obiettivi e considerazioni sull’esperienza. Nel capitolo conclusivo viene proposto un bilancio delle esperienze realizzate, evidenziando punti di forza e aree di miglioramento dei progetti, con la finalità di condividere suggerimenti ed idee per tracciare percorsi formativi maggiormente efficaci nel futuro.

Description: Published

Description: 119-131

Description: 2TM. Divulgazione Scientifica

Description: N/A or not JCR

Description: “Move, protect, secure” were the three key points that the KnowRISK (Know your city, Reduce seISmic risK through non-structural elements) project posed at the core of its communication and dissemination strategy. This three key points enable each person, professional or not, to reduce non-structural damage caused by earthquakes. Dissemination is usually the last but never the least step of a communication plan, and indeed it played a crucial role in KnowRISK project for conveying the three key-point message to the widest audience. Standard dissemination activities, such as open-door events, and internet allowed us to achieve a wide spreading of ideas and best practices, reaching more than 4,000 non-professionals and almost 50,000 page views of the KnowRISK project website (in three years), respectively. As communication was recipient-targeted, the dissemination task of the project was addressed to professionals, layman, and schools. In particular, schools were chosen in order to profit from the chain-reaction action that is capable to spread a message from students to the surrounding environment.

Description: This study was co-financed by the European Commission’s Humanitarian Aid and Civil Protection through the European project KnowRISK (Know your city, Reduce seISmic risK through non-structural elements; Grant agreement ECHO/SUB/2015/718655/PREV28).

Description: Published

Description: SE328

Description: 6T. Studi di pericolosità sismica e da maremoto

Description: JCR Journal

Description: We present the commented transcription of three rare articles published in 19091910 by Father Atto Maccioni o.f.m. This friar is one of the least known among the many ecclesiastics who cultivated seismology from the 18th century onwards. Maccioni, from 1908 to 1926, managed a seismic observatory at the Sienese convent of the Osservanza. He devised an “Avvisatore”: a device equipped with a modified coherer with respect to those adopted in radiotelegraphic communications, aimed to detect natural radio signals associated with earthquakes. From the few available results it seems that the scholar obtained positive feedback, but the most interesting aspect of the story is that until now it was generally believed that this kind of research began only quite recently [Warwick, 1982]. On the contrary Maccioni may have been the first ever to study a possible electromagnetic precursor, more than a century ago.

Description: Presentiamo la trascrizione commentata di tre rari articoli pubblicati nel 19091910 da padre Atto Maccioni o.f.m., uno dei meno noti tra i tanti ecclesiastici che si sono occupati di sismologia dal XVIII secolo in poi. Maccioni, che dal 1908 al 1926 gestì un osservatorio sismico presso il convento senese dell’Osservanza, aveva ideato l’Avvisatore, un dispositivo munito di un coherer diverso da quelli radiotelegrafici e destinato a rilevare segnali radio naturali associati ai terremoti. Dai pochi risultati disponibili sembra che lo studioso abbia avuto dei riscontri positivi ma l’aspetto più interessante della vicenda è che finora si era creduto che ricerche di questo tipo fossero iniziate solo molto di recente [Warwick, 1982]. Invece Maccioni potrebbe essere stato il primo al mondo a studiare, più di un secolo fa, un ipotetico precursore elettromagnetico.

Description: Published

Description: 1-32

Description: 7T. Variazioni delle caratteristiche crostali e "precursori"

Description: 2TM. Divulgazione Scientifica

Description: N/A or not JCR

Description: La Cromatografia Ionica (IC) è diventata una delle tecniche analitiche più utilizzate nella determinazione degli anioni (F-, Cl-, Br-, NO3-, SO42-) e dei cationi (Li+, Na+, K+, Mg2+, Ca2+) in soluzioni acquose, anche a basse concentrazioni. Nel Laboratorio dell’INGV Sezione di Palermo questa tecnica viene utilizzata per determinare la composizione chimica di acque naturali (acque sotterranee, termali, meteoriche, marine), di fluidi fumarolici, campionati tramite il metodo delle ampolle di Giggenbach e delle specie acide emesse dai pennacchi vulcanici campionati con trappole alcaline. Ogni anno nel laboratorio vengono analizzati numerosi campioni per scopi di ricerca e monitoraggio geochimico e ambientale. Uno dei principali problemi dell’attività analitica di routine è la valutazione della precisione del dato, definita dall’American Public Health Association [1999], “come la misura del grado di accordo tra analisi replicate di un campione, di solito espresse come deviazione standard”. Tralasciando I problemi di rappresentatività del campione, ci sono diversi fattori che contribuiscono alla precisione, come il pretrattamento del campione, la preparazione e conservazione delle miscele di calibrazione, la ripetibilità delle misure delle aree dei picchi delle miscele di calibrazione e il tipo di calibrazione. In questo lavoro mostriamo la precisione dei cromatografi Dionex ICS-1100 ripetendo più volte l’analisi le miscele di calibrazione durante una singola sessione analitica, e la ripetibilità dello strumento, elaborando I risultati ottenuti analizzando le stesse miscele di calibrazione in differenti sessioni analitiche nell’arco di 12 mesi. Infine, viene determinata l’accuratezza del metodo attraverso l’analisi di un campione certificato. L’accuratezza è la vicinanza tra il valore osservato ed il valore vero, o comunque accettato come tale. I dati riportati in questo rapporto tecnico si riferiscono alle condizioni analitiche per le analisi di routine, con la configurazione strumentale corrente in uso presso questo laboratorio; queste possono essere ottimizzate per altri range di utilizzo a condizione però che vengano eseguite le necessarie verifiche di precisione e accuratezza.

Description: Istituto Nazionale di Geofisica e Vulcanologia (INGV) “Sez. di Palermo”

Description: Published

Description: 1-22

Description: 2IT. Laboratori analitici e sperimentali

Description: N/A or not JCR

Description: A new indirect method of estimating in situ soil air permeability is presented in this technical report. The new method is simply based on the measurement of air pressure (probe pressure) generated by pumping a constant air flux inside a special designed probe inserted into the soil. To calibrate the method, some measurements of the probe pressure were performed in some soils of the island of Vulcano, characterized by different values of the air permeability. Furthermore, technical aspects of a new device for performing continuous acquisition of the air permeability based on the new indirect method, were also described

Description: Istituto Nazionale di Geofisica e Vulcanologia (INGV) “Sez. di Palermo”

Description: Published

Description: 1-18

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: N/A or not JCR

Description: La determinazione di anioni inorganici nelle acque naturali, sotterranee e superficiali, cosi come nelle acque reflue e potabili, è una delle applicazioni più importanti della cromatografia ionica (IC). Con questa tecnica si possono comunemente determinare i principali anioni inorganici: fluoruro, cloruro, bromuro, nitrato e solfato. Utilizzando specifiche metodologie oltre ai predetti analiti, si può determinare anche il fosfato durante la medesima analisi. La determinazione dei fosfati nelle acque riveste una notevole importanza in considerazione del fatto che il fosfato rappresenta un possibile indice di inquinamento per la presenza di questa sostanza in moltissimi composti chimici, quali: detersivi domestici ed industriali, fertilizzanti ecc. La quantità di fosfati, nelle acque naturali, quando è di origine minerale e non indica inquinamento, raggiunge concentrazioni appena dosabili, mentre concentrazioni elevate e quindi misurabili, sono indice di inquinamento. Il fosfato è uno dei nutrienti di maggiore importanza nelle acque, la sua presenza in concentrazioni consistenti, può essere responsabile di manifestazioni eutrofiche ed ipertrofiche nelle acque superficiali. Data la sua importanza nel condizionare il funzionamento degli ecosistemi acquatici, esso è incluso nella lista dei cosiddetti macrodescrittori utilizzati per definire lo stato chimico delle acque fluviali e lacustri e per valutare, lo stato trofico delle acque. La determinazione del fosfato viene comunemente effettuata utilizzando l’analisi spettrofotometrica dell’eteropoliacido fosfomolibdico formatosi in seguito alla reazione con molibdato in ambiente acido ed in presenza di idoneo riducente. Tuttavia questo, metodo ampliamente utilizzato, consente la determinazione del singolo analita e non consente quindi la caratterizzazione chimica del campione. La cromatografia ionica, invece, presenta il vantaggio di essere una tecnica multi-elementare che consente di determinare in breve tempo tutti i costituenti maggiori disciolti nelle acque. In questo rapporto tecnico viene descritta la determinazione del fosfato e dei costituenti maggiori nelle acque naturali utilizzando, un cromatografo Thermo Scientific Dionex ICS 5000+, equipaggiato con una colonna a scambio anionico “Dionex AS19 4µm”, un generatore di eluente a idrossido di potassio (KOH), un soppressore elettrochimico ed un rivelatore a cella conduttimetrica.

Description: Istituto Nazionale di Geofisica e Vulcanologia (INGV) “Sez. di Palermo”

Description: Published

Description: 1-22

Description: 2IT. Laboratori analitici e sperimentali

Description: N/A or not JCR

Description: Il sito delle “Ciampate del diavolo”, sul fianco nord­orientale del vulcano Roccamonfina, è un sito unico al Mondo grazie alle sue peculiarità geologiche ed antropologiche. Il ritrovamento di impronte di hominini al di sopra di un deposito ignimbritico, impresse in nel periodo di maggiore attività del vulcano, dà spazio a numerose questioni circa le condizioni paleoambientali esistenti sul vulcano ed i complessi processi che hanno permesso la formazione e la conservazione delle impronte. La nota dedica particolare attenzione al contesto dell’attività del vulcano ed alle caratteristiche della serie dei Tufi Leucitici Bruni, in quanto le impronte note come “Ciampate del diavolo” sono presenti sulla superficie di una delle unità più alte della sequenza di questi tufi. The “Ciampate del diavolo” geosite is unique in the World due to its geological and anthropological peculiarities. Finding hominin footprints on the ignimbrite deposits of 350,000 years ago, imprinted in the period of greatest activity of the volcano, opens up numerous questions about the palaeoenvironmental conditions of the volcano and the complex processes that allowed the generation and conservation of the footprints. The note pays particular attention to the framing of the volcano's activity and to the features of deposits of the Brown Leucitic Tuff series, as the human fossil footprints known as "Ciampate del Diavolo" are preserved on the surface of one of the highest units in the sequence.

Description: Published

Description: 49-55

Description: 1V. Storia eruttiva

Description: 5V. Processi eruttivi e post-eruttivi

Description: 1TR. Georisorse

Description: 6SR VULCANI – Servizi e ricerca per la società

Description: N/A or not JCR

Description: Mts. Simbruini karst aquifer feeds important springs whose capture contributes to the water supply of Rome City. To improve the geochemical characterization of this aquifer, we analyzed 36 groundwater samples, 29 from springs and 7 from shallow wells, collected in 1996 and 2019. Atomic adsorption spectroscopy, titration, ionic chromatography and mass spectrometry were the used analytical methods. Groundwater is bicarbonate alkaline-earth type and HCO3- dominance confirms that the aquifer is hosted in carbonate rocks. Total alkalinity vs. cations plot indicates that CO2 driven weathering controls the water chemistry. The probability plots of HCO3-, cations and Ca2+ +Mg2+ indicate four groundwater populations with the less represented one (9 samples)characterized by the highest PCO2 values (〉 0.3 atm). Most anomalous values of the dissolved PCO2are from springs located near the center of the studied area. Four samples have negative values of𝛿13CCO2 (about -22‰ vs. PDB), indicating its organic origin, but two other samples have positivevalues (1.6 and 2.6 ‰ vs. PDB), similar to those observed in the CO2 of deep origin discharged atthe close Colli Albani volcano. Therefore, geochemical evidence indicates that the Mts. Simbruiniaquifer is locally affected by the input of deep originated CO2, likely rising up along fractures, interacting with a recharge of meteoric origin, as evidenced by its 𝛿2H and 𝛿18O isotopic signatures.

Description: Published

Description: HS659

Description: 1TR. Georisorse

Description: JCR Journal

Description: The best chance to achieve a future disaster-resilient society is through risk education in School: it has a great potential to strengthen capacity of communities to mitigate risks. The KnowRISK (Know your city, Reduce seISmic risK through non-structural elements) project took this opportunity and implemented a risk communication campaign for schools in Portugal, Italy, and Iceland. The idea was that suitably changes in people’s knowledge and attitude can trigger best practices. Crucial to reach such target is the raise of awareness on meaningful issues. The main challenge of the campaign was how to effectively address the mitigation of the vulnerability to earthquakes of non-structural elements, which is an issue considered to be of low priority even in the building regulations of many countries around the world. The campaign stood on a communication strategy that was systematized within a protocol, for 13- 15 years old students, that specifies goals, contents, learning strategy, support material, and relies on face-to-face intervention of scientists in the classroom. This protocol had training sessions bounded by assessment sessions, ex-ante and ex-post, that allowed to validate its efficacy. The training made large use of flipped learning and Episode of Situated Learning (EAS) strategy to raise student’s motivation and increase achievements. To ensure its replicability, the protocol was tested in zones matching a wide range of seismic hazard in Italy. The assessment showed the protocol be effective and ready for a wide dissemination.

Description: Published

Description: SE325

Description: 2TM. Divulgazione Scientifica

Description: JCR Journal

Description: In aree di vulcanismo attivo e recente, oltre all’emissione di vapore e gas dai crateri centrali, si possono verificare emissioni di gas dal suolo che vengono rilasciati in modo diffuso o in mofete, o ancora che si disciolgono in acquiferi superficiali. Generalmente il gas più abbondante (fino al 99 vol.%) è l’anidride carbonica (CO2), ma in alcuni casi può essere anche il metano (CH4). La CO2 è un gas incolore e inodore che tende ad accumularsi in depressioni o scantinati dove ristagna in assenza di vento. Respirare aria con una concentrazione di anidride carbonica maggiore di 8 vol.% può condurre all’incoscienza o alla morte. Un esempio di quello che potrebbe accadere, anche se si tratta di un caso estremo, è rappresentato dal tragico evento avvenuto presso il lago Nyos in Camerun (un lago ospitato in un cratere vulcanico). Durante la notte del 21 agosto 1986 le acque del lago, sature di CO2, si rovesciarono improvvisamente e per decompressione si liberò una enorme quantità di gas che scese lungo i fianchi del cratere fino a raggiungere la valle sottostante dove vi era un villaggio. La nube di CO2, silenziosa e inodore, colse nel sonno gli abitanti e uccise circa 1700 persone e circa 3000 capi di bestiame [Barberi et al., 1986]. Numerosi incidenti dovuti all’inalazione di gas vulcanici sono avvenuti in varie altre parti del mondo, in particolare in Italia, Giappone, Nuova Zelanda [Hansell and Oppenheimer, 2004; Durand and Wilson, 2005] e nelle Isole Azzorre (Portogallo) [Viveiros et al., 2015]. Anche in Italia, purtroppo sono avvenuti diversi incidenti letali dovuti ad inalazione di CO2; si ricorda ad esempio che alla fine degli anni ’80 due bambini persero la vita nell’isola di Vulcano [Baubron et al., 1990] e ancora nel complesso vulcanico dei Colli Albani due uomini persero la vita, il primo a Cava dei Selci (frazione di Marino) nel 2000 e il secondo a Lavinio nel 2011 [Carapezza et al., 2003; Barberi et al., 2019]. Sempre in provincia di Roma, numerosi casi di intossicazione da CO2, che hanno altresì comportato l’evacuazione temporanea di alcune abitazioni, sono avvenuti per blowout (emissione incontrollata) di gas da pozzi d’acqua [Barberi et al., 2007; Carapezza et al., 2020]. La Campania ospita due dei vulcani quiescenti considerati tra i più pericolosi al mondo proprio per l’alta densità di popolazione che vive nelle zone esposte al pericolo: il Vesuvio e i Campi Flegrei. Anche in queste aree vulcaniche si hanno emissioni di gas endogeni e falde d’acqua ricche in CO2 e in caso di riattivazione del vulcano c’è da aspettarsi anche un forte incremento del rilascio del gas endogeno [Barberi et al., 2005]. Al fine di far conoscere tale problematica alla popolazione, si è ritenuto opportuno di agire sui ragazzi e di farlo in modo stimolante e divertente attraverso un Videogioco che catturi la loro attenzione in modo da portarli a scoprire le soluzioni più adeguate da adottare per individuare/evitare/gestire i pericoli legati a quello che spesso viene definito anche “carburante delle eruzioni”, i gas vulcanici. Le attività che hanno portato alla realizzazione di questo lavoro (e nello specifico del videogioco) sono state svolte nell’ambito del Progetto Europeo RESPIRE – Radon rEal time monitoring System and proactive Indoor Remediation (LIFE16ENV/IT/000553) e con la collaborazione di un Tirocinante del Dipartimento di Ingegneria dell’Informazione ed Elettrica e Matematica Applicata dell’Università degli Studi di Salerno. Il lavoro è stato descritto e sintetizzato in questo Report attraverso varie sezioni. La prima in cui si descrive la problematica dei Gas Vulcanici e della loro pericolosità; l’importanza e i vantaggi derivati dall’utilizzo di un videogioco come strumento di apprendimento; l’obiettivo che il videogioco si prefigge di raggiungere. Una seconda sezione in cui, in prima istanza, si evidenzia l’importanza di sviluppare un videogioco a partire da un Motore Grafico che consente di tralasciare i dettagli hardware e software di basso livello e di concentrarsi maggiormente sull’interattività e sulle regole del gioco, e in seconda istanza si descrivono le caratteristiche principali del motore grafico alla base del gioco (RPG Maker MV).Una terza sezione in cui viene presentato il videogioco sviluppato denominato “GioGas”; nello specifico, la sua trama, l’interfaccia grafica che lo caratterizza e alcuni sui dettagli implementativi. Infine, una sezione in cui vengono descritti gli sviluppi futuri come ad esempio la divulgazione presso le scuole e in occasione di eventi, l’implementazione di una versione multiplayer del gioco al fine di aggiungere ulteriori elementi di stimolo e di coinvolgimento per lo studente.

Description: Published

Description: 6SR VULCANI – Servizi e ricerca per la società

Description: N/A or not JCR

Description: PGS1 is a new compact portable seismic station, designed at INGV OBS and Earth Lab, that is specifically intended for the deployment of dense arrays of seismographs on-shore. With its low cost, compact design, high data-quality and long battery life, PGS1 is a perfect solution for seismic monitoring networks. PGS1 design is based on a solid polypropylene suitcase, containing a complete data acquisition system, two battery packs and a photovoltaic panel. The new Earth Lab 5s medium-period seismic sensor is included. The whole system meets the IP67 standard requirements both in transport and in acquisition configuration. PGS1 is normally equipped with one battery pack, one more pack can be added inside the suitcase achieving 40 days of battery life. The station is equipped with a photovoltaic panel, useful to extend the deployment length. Inside the suitcase, there are compartments where to store the seismic sensor, the photovoltaic panel and all the cables. Therefore, the station is very easy to transport.

Description: Published

Description: SE105

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: JCR Journal

Description: Low field magnetic susceptibility and other rock magnetic analyses are applied to inspect the magnetic nature of solid residuals in snow samples collected in downtown Rome and in two Natural Parks in central Italy. Field emission scanning electron microscope and energy dispersive spectroscopy (FESEM-EDS) analyses are utilized to reveal the nature of Fe-rich particles and discriminate their anthropogenic origin. The results indicate that magnetite (Fe3O4) is the main magnetic carrier in almost all samples and that the variations in concentration are directly associated with local sources of particulate matter (PM) from anthropogenic pollution related to automotive circulation in both environments. Magnetic minerals of other provenance are found as accessories. The snow deposits revealed to be an efficient neutral tool for fine particle collections, also in environments characterized by different concentration and source of pollutants.

Description: Published

Description: GM215

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: JCR Journal

Description: The 1971 eruption represents a benchmark in the recent history of Etna volcano. From a volcanological point of view, this eruption was characterised by complex intrusive dynamics associated with significant ground deformation that induced the activation of the Moscarello seismogenic fault and the formation of a new summit crater: the Southeast Crater. At the same time, the 1971 event marks an important change in the eruptive style and composition of the magma towards products richer in K. It is no coincidence that, over the next fifty years, there would be an increase in the frequency of summit and flank eruptions and associated output rate. From an historical viewpoint, the eruptive event of 1971 was the first important flank eruption studied by the International Institute of Volcanology: the analysis of the scientific articles on this activity reveals a greater multidisciplinary content in the descriptions and explanations of volcanic activity. Particularly important were the collaborations of British and French research groups that, together with their Italian colleagues, succeeded in giving a complete picture of the eruption and describing the state of knowledge on the Sicilian volcano. The multidisciplinary methodology used to study this eruption is still valid today.

Description: Published

Description: VO543

Description: 1V. Storia eruttiva

Description: JCR Journal

Description: This study analyses the relationship between the pre- and protohistoric sites on the slopes of Etna and the volcanic products, as well as the diverse settlement strategies in the different periods of prehistory. New C14 dating from significant excavations, in addition to those known from other Etnean sites, were performed with the aim of validating the chronology of the sequence of the different phases. A substantial concordance of the archaeological data with the volcanological ones has been found. It has been observed that a consistent human presence on Etna appears from the Middle Neolithic (5500 BC), after the sequence of eruptive events that marked the end of the Ellittico volcano (13550 - 13050 BC) and the formation of the Valle del Bove, and the subsequent debris and alluvial events on the eastern flanks of the volcano (7250 - 3350 BC). Human presence intensifies between the Late-Final Copper Age and the Early Bronze Age (2800 - 1450 BC), due to improvement in subsistence techniques and to the large presence of soils on lava flows suitable for sheep farming. The most recent phases of the Bronze Age are poorly represented, probably because of the concentration of the population in larger agglomerations (Montevergine and S. Paolillo at Catania, the Historical Hill at Paternò). The explosive eruptions taking place in this period seem to have had less impact on the settlement choices and have not affected the development of the sites over time.

Description: Published

Description: VO542

Description: 1V. Storia eruttiva

Description: JCR Journal

Description: This special issue of Annals of Geophysics entitled: “When Volcanologists Meet Archaeologists and Other Disciplines: Relationships Between Eruptions and Human Communities” originates from a session (S13) of the Rittmann International Conference which took place in Catania on February 13th 2020, having as its main theme the history of volcanology and the impact of volcanic activity on humans. The twelve articles collected in this special issue reflect the aims and contents of the reports presented by some participants at this session of the Rittmann conference

Description: Published

Description: 6SR VULCANI – Servizi e ricerca per la società

Description: JCR Journal

Description: Published

Description: 6TM. Poli Museali

Description: The Western Ionian Sea is characterised by an active and diffuse seismicity, directly related to the convergence of the European and African Plates and by gravitational sinking and rollback of the oceanic lithosphere. In this area, the location of earthquakes is characterised by considerable uncertainties due to large azimuthal gaps, resulting in notable location errors. This problem was partially overcome with the use of data recorded by NEMO-SN1 seafloor observatory (October 2002 - February 2003; June 2012 - May 2013). We relocated 1130 crustal and sub-crustal earthquakes using land network and NEMO-SN1 data. As most events occurred on Mt. Etna, we focused on 358 earthquakes in the offshore area and near the coasts of Sicily and Calabria. The use of the combined land-marine networks has improved the earthquake locations in terms of azimuthal GAP, as well as in horizontal and vertical errors. The comparison between locations performed with and without NEMO-SN1 data shows that differences in latitude, longitude and depths are more evident in the Western Ionian Sea and in the coast of Sicily, where values of the differences over 5 km correspond to structural heterogeneities. The increased number of seismic stations deployed on land from 2003 to 2012 did not influence the location of events occurring offshore, where NEMO-SN1 continued to be the distinctive tool in the location process. Moreover, the new 73 focal mechanisms computed with P-wave polarities from NEMO-SN1 and land stations are in agreement with the regional structural model, showing a prevalent normal, normal/oblique, and strike-slip kinematics. The similarity of two new focal solutions with the mechanisms of the main shock and aftershock of the 1990 earthquake demonstrates that the seismic structures are still active and potentially dangerous. The P-wave travel time residual analysis confirms the activity along the main structural alignments. A single point of observation in the Ionian Sea can significantly improve the quality of locations, giving an opportunity to focus on the seismogenic structures responsible for the occurrence of medium-to-high magnitude earthquakes.

Description: Published

Description: Se655

Description: 1T. Struttura della Terra

Description: JCR Journal

Description: The 8 September 1905 Calabria earthquake is the seismic event for which the Italian Seismic Catalogue shows the highest instrumental magnitude of the whole dataset. However, the reported MS = 7.47 was calculated over only two stations, and leaves room for a revision. In this work I provide a new estimate of the surface-wave magnitude of the earthquake calculated over sixteen individual values of magnitude from seven different stations. The new estimate is MS = 7.10 ± 0.21, a value that is consistently lined up with other estimates provided by means of macroseismic or geological evidence. The novel estimate is stable despite alternative epicentral locations and different depths proposed for this event by several investigators. The net variation of almost half a unit magnitude implies a resizing of the seismogenic source of the event in the frame of the seismotectonics of the region, and highlights the strong need for a systematic revision of the instrumental magnitude estimates for several ‘historical’ earthquakes that occurred at the dawning of the instrumental seismology.

Description: Published

Description: SE658

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: Usually seismicity is intended as a natural phenomenon; yet the recording and interpretation of data are a human undertaking, historically conditioned. This research starts from the hypothesis that the decrease in Italian seismicity observed in the historical catalog [Rovida et al., 2021] for the central years of the twentieth century is due to the social and political conditioning that hindered its registration. This work, which focuses on the 1930s, with a brief excursion into previous years, presents part of the results obtained. In particular, the article deals with three earthquakes of which the data are substantially updated (Calabria, 7.03.1928; Alpi Noriche, 14.05.1930; Valli Giudicarie, 14.04.1931); then it presents an important replica of the strong Maiella earthquake, without macroseismic data in the catalog [Rovida et al., 2021], (Maiella, 23.11.1933); finally it considers a “forgotten” fifth earthquake (Southern Italy, 13.04.1938).

Description: Published

Description: 1-78

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: Le finalità del progetto sono quelle di realizzare un prototipo di ionosonda per sondaggi obliqui basato sul principio del radar ad onda continua modulata in frequenza, implementato tramite dispositivi programmabili innovativi che permettono di realizzare uno strumento più piccolo e trasportabile rispetto alle ionosonde classiche. La ionosonda SDR è un radar bistatico costituito da un trasmettitore, che può servire contemporaneamente diversi ricevitori situati in località differenti, e da uno o più ricevitori che possono sintonizzarsi su differenti trasmettitori che effettuano sondaggi ad orari differenti. I sondaggi obliqui permettono di mappare la ionosfera in varie parti del territorio per la verifica di modelli teorici della ionosfera e per studiare la possibilità di usare le variazioni locali del Contenuto Elettronico Totale (TEC) come segnale di possibili precursori di terremoti.

Description: Published

Description: 1-32

Description: 6IT. Osservatori non satellitari

Description: N/A or not JCR

Description: The Istituto Nazionale di Geofisica e Vulcanologia (INGV) was born from the unification of public research institutions in the field of geophysics and volcanology. In the first twenty years from the foundation law of 1999, the INGV has seen a remarkable development, alternating moments of expansion, with significant increases in funding and number of employees, with long periods of stagnation. During these years the number of people hired with fixed-term contracts has grown, also to meet the needs of seismic and volcanic monitoring of the Italian territory, carried out on the basis of agreements with the Department of Civil Protection. After twenty years, it's time to outline a picture of the present situation and the evolutionary process that determined it. With this objective, the following analysis of the evolution of INGV was carried out in the period between its establishment and 2019, with reference to aspects such as the composition of the personnel, its distribution in the Sections, age, gender, role, career, with the aim of providing a tool for evaluating the progress made and planning future developments. The presence of a large number of precarious workers, distributed unevenly in territorial offices, for many years represented the main problem of the INGV, but not the only one. The contraction of the funding and the hiring freeze also slowed the development of the careers of researchers and other employers. The poor gender balance among the personnel, in particular among researchers, and the high average age represents further critical elements. The appropriate rebalancing of heterogeneities, aimed at maximum functionality and effective growth of the institute, should be the challenge for the next years. The future of INGV will depend on the choices that will be made today and the knowledge of the evolution of the institution until today is an essential element for proper programming.

Description: Published

Description: 1-92

Description: 3TM. Comunicazione

Description: JCR Journal

Description: Istituto Nazionale di Geofisica e Vulcanologia

Description: Published

Description: 1-186

Description: 1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: 1TM. Formazione

Description: 2TM. Divulgazione Scientifica

Description: N/A or not JCR

Description: This contribution illustrates the state of the art on the development of the multiparametric network in Sicily in the last three years. This region is wellknown for the strong earthquakes (M〉6.5) which struck in historic time. However, the coverage of the seismic network developed in the last decades was not fully optimized to the need of the seismic surveillance. Since 2017, the group belonging to the National Earthquake Observatory (ONT) which operates in Sicily launched a developing plan of the preexisting seismic network in the framework of the project FISR “Sale Operative Integrate e Reti di Monitoraggio del futuro: l’INGV 2.0 (S.O.I.R.)”. Such update will end by the next years thanks to the project “GRINT Italian Research Infrastructure for Geosciences” in the framework of the “Programma Operativo Nazionale” (PON) of the Italian Ministry for the University and Research. This plan envisages both the upgrade of monitoring systems in the already existing nodes, and the integration of new nodes. The main objective is to build a multiparametric network which integrates the main seismic network, with the monitoring of other geophysical signals through the implementation of other sensors: accelerometers, geodetic GPS, radon detectors, and corner reflectors. We also illustrate the plan for the realization of a redundant network which could support the tasks of the main infrastructure in case of failure of the latter. Finally, we present some experimental urbanscale networks which in the future could support the main infrastructure.

Description: Published

Description: 1-40

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: JCR Journal

Description: The present paper describes the process of moving from a research study of most common vulnerable non-structural elements, to deliver solutions, tools and guidelines to improve understanding of and responsiveness to community concerns about seismic risk and non-structural elements. The observed damage to non-structural elements following recent earthquakes in Italy, Portugal and Iceland, were used for designing communication tools under the KnowRISK EU project for multi-stakeholders (students, business and citizens): the Practical Guide, the Students Short Guide, the KnowRISK Portfolio of Solutions, the Move, Protect and Secure video, the augmented reality apps, the maquettes, the students notebooks, videos, board games and hands-on tools. The philosophy behind these deliverables is that some risks, once identified, can be eliminated or reduced by informing people and suggesting preventive or emergency measures. These tools are devoted to improving the seismic performance of non-structural elements and to reduce the associated economic losses, loss of functionality, and potential threats to life safety. The rationale behind the selection of the information that people need to know for converting knowledge to more safety is discussed and a description of the transference of the findings of research to communication solutions is presented. The tools were planned following the engagement-model in risk communication to ensure that needs of communities and selected stakeholders were acknowledged, and that recipients are addressed in a way that appeals to them. Different media and communication channels such as print, television, online, face-to face communication and interviews were used for risk communication.

Description: This study was co-financed by the European Commission’s Humanitarian Aid and Civil Protection (Grant agreement ECHO/SUB/2015/718655/PREV28).

Description: Published

Description: SE322

Description: 5T. Sismologia, geofisica e geologia per l'ingegneria sismica

Description: JCR Journal

Description: The lava platform and the three pyroclastic cones of Vulcanello constitute the northernmostvolcanic structure of the island of Vulcano (Aeolian Islands). The sandy isthmus connecting theplatform to the main island was definitively formed in the first half of the 1500s; before then,Vulcano and Vulcanello were two close but separate islands. For a long time, the interpretation ofthe sources of the II-I century BC, had considered the islet as built up about 2200 years ago. Thisbelief, which proliferated among naturalists from the 17th century, is not confirmed in the ancienttexts or even in the geographical documents of the time, which do not indicate the presence ofVulcanello as a new and stable island near Vulcano. The islet would only be mentioned at the dawnof the second millennium, and named in Arabic “Gabal’ al Burkān”, meaning Mount of Vulcano;shortly thereafter the toponym changed to the Latin “Insulam Vulcanelli” and then, towards the15th century, finally to Vulcanello.Since the creation of a volcanic island certainly occurred in the Aeolian Islands in the classical era,but traces of it were quickly lost, the most plausible hypothesis is that it was formed in the area ofthe current Vulcanello, to be subsequently erased by the sea. The shallow, flat seabed, likelyremaining as a result of sea abrasion, might have represented the morphological element on whichthe circular lava platform we know today was formed sometime between 950 and 1000 AD.

Description: Published

Description: VO548

Description: 1V. Storia eruttiva

Description: JCR Journal

Description: On November 20, 2019, an exercise was held at the National Institute of Geophysics and Volcanology (INGV) as part of the activities planned for preparing for seismic emergencies. The training was "tabletop" with the simulation of an earthquake with a magnitude greater than the threshold required for the activation of the intervention procedures, described in the "Protocol of the Authority for the management of seismic and tsunami emergencies and Establishment of the Crisis Unit”, the flow of actions that follow was verified. The exercise involved the entire INGV even if the Rome headquarters was the most involved, and it was the second of this type after that carried out in 2015 [Pondrelli et al., 2016]. Main motivation of this training was the analysis of the efficiency of the Organization Protocol, a document that for the first time at INGV codifies the actions of the Crisis Unit and of the Institute in general on the occurrence of seismic events and / or seismic sequences and / or tsunamis. The Protocol has been formalized on the basis of the numerous experiences that the Institute has supported over many years, to honour its vocation in the monitoring and seismic surveillance of the national territory [Margheriti et al., 2021].

Description: Published

Description: 1-50

Description: 2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto

Description: N/A or not JCR

Description: The influence of the Atlantic multidecadal variability (AMV) on the North Atlantic storm track and eddy-driven jet in the winter season is assessed via a coordinated analysis of idealized simulations with state-of-the-art coupled models. Data used are obtained from a multimodel ensemble of AMV± experiments conducted in the framework of the Decadal Climate Prediction Project component C. These experiments are performed by nudging the surface of the Atlantic Ocean to states defined by the superimposition of observed AMV± anomalies onto the model climatology. A robust extratropical response is found in the form of a wave train extending from the Pacific to the Nordic seas. In the warm phase of the AMV compared to the cold phase, the Atlantic storm track is typically contracted and less extended poleward and the low-level jet is shifted toward the equator in the eastern Atlantic. Despite some robust features, the picture of an uncertain and model-dependent response of the Atlantic jet emerges and we demonstrate a link between model bias and the character of the jet response.

Description: Published

Description: 347-360

Description: 4A. Oceanografia e clima

Description: JCR Journal

Description: Il mondo della Ricerca e dell ’Innovazione Tecnologica per sua natura è sempre in evoluzione, ed accompagnato da normative in materia di Sicurezza e Salute non sempre conosciute o applicate. La particolare enfasi data alla formazione nel quadro normativo riguardante la Sicurezza e Salute nei luoghi di lavoro, sia a livello nazionale che comunitario, dimostra e determina l’importanza attribuita a tale processo, non solo come mezzo elettivo per la diffusione della cultura della Sicurezza a tutti i livelli , ma anche, e soprattutto, come misura generale di tutela.

Description: Istituto Nazionale di Geofisica e Vulcanologia

Description: Published

Description: 1-54

Description: 1TM. Formazione

Description: N/A or not JCR

Description: Within a fault governing model the characteristic scale length is one of the most relevant physical parameters because it accounts for the so–called fracture energy (density) of the system, its dynamics, the time during which the accumulated stress is released and the seismic waves are excited, the amount of slip developed during an instability event. Friction laboratory experiments reveal that it is not a material property, but that it changes with the sliding velocity. We propose two rather different analytical models to fit laboratory evidence and we incorporate them into a fault model able to simulate repeated earthquakes in the framework of various formulations of rate and state friction. We demonstrate that temporal variations of the scale length do not prevent the system to reach its limit cycle, but they systematically reduce the magnitude of the expected event (both in term of developed slip, and thus seismic moment, and released stress) and also reduce the inter–event time (recurrence interval). Depending on the friction model, the system can penetrate into the stable regime and can either continue the accelerating phase toward to failure or decelerate and abort instability.

Description: Published

Description: SE217

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: The understanding of the ancient Earth’s Magnetic Field strength, or absolute paleointensity, is fundamental for several disciplines of Earth Sciences. Following the growing interest in this field in the last decades, the number of paleointensity studies has been increasing and the Paleomagnetic Laboratory of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) in Rome, Italy expanded the instrument park with a ASC TD48SC oven for paleomagnetic and paleointensity measurements. This manual represents an updated version of the original manual “Guida all’uso del forno ASC TD48SC per la stima della paleointensità assoluta con il metodo ThellierThellier modificato” [Di Chiara, 2014]. The aim is to provide a practical guide for paleointensity measurements, using the IZZIThellier experiment and the software Thellier_GUI for the processing of the geomagnetic field strength or paleointensity data.

Description: INGV

Description: Published

Description: 1-20

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: N/A or not JCR

Description: We describe the geochemical characteristics of groundwater samples collected in 23 water wells located on the northern margin of the Hyblean plateau (East Sicily). This area, mostly made of highly permeable carbonate rocks, is rich in low temperature (T 〈 50° C) hydrothermal groundwaters, distributed in an active sismogenetic zone, with several ENE-WSW-directed tectonic structures that drove magma to the surface during Upper Pliocene and Pleistocene. The chemical features suggest complex mixing between rainwater, CO2-rich groundwater, steam-heated groundwater and geothermal brines, as highlighted by Principal Component Analysis (PCA). Some parameters, however, indicate widespread pollution of the aquifers from human activities. Stable isotopes analysis confirms the meteoric origin of groundwater and supports the origin of dissolved CO2 mostly from mantle degassing through deep tectonic faults. Geothermometric estimates, mostly based on quartz and Saturation Indexes geothermometers, suggest minimum reservoir temperature between 100 and 120° C.

Description: Published

Description: HS438

Description: 1TR. Georisorse

Description: JCR Journal

Description: A ground magnetic study was performed on the northern upper flank of Mt. Etna to provide new insights into subsurface volcano-tectonic structures. The high resolution magnetic survey was focused on the main structures of Piano delle Concazze, a large flat area dominated by the North- East crater and bounded by the rim of the Valle del Leone depression and the extremity of the North-East Rift. More than 2,500 measurements were gathered with a sampling step of about 3 m covering an area of about 0.2 km2. The total-intensity anomaly field shows the presence of intense South-North aligned maxima related to shallow geological structures affecting this area. Filtering techniques and 2.5D modeling have been applied for the determination of the magnetic source parameters. In order to distinguish the near surface structure, filters of the vertical derivatives, Butterworth high-pass and the tilt derivative were used. The 3D Euler deconvolution has been applied to estimate the depth and the structural indices of the causative sources. The calculated structural indices, that express the geometrical nature of the source, are in agreement with forward modeling. They show that the area is mainly affected by subvertical normal fault and the estimated depth of magnetic sources ranges between 10 m and 40 m. Our total field magnetic survey shows that characteristic magnetic anomalies are related to fault zones in the Piano delle Concazze that are well consistent with the local tectonics. The subsurface structures that have been detected allowed to delineate the general structural framework of the area. In particular, it was possible to clarify that these structures seem to be not deep rooted and consequently they can hardly act as preferential pathways for magma ascent.

Description: Published

Description: PE108

Description: 2V. Struttura e sistema di alimentazione dei vulcani

Description: JCR Journal

Description: The traction evolution is a fundamental ingredient to model the dynamics of an earthquake rupture which ultimately controls, during the coseismic phase, the energy release, the stress redistribution and the consequent excitation of seismic waves. In the present paper we explore the use of the friction behavior derived from laboratory shear experiments performed on granular materials at low normal stress. We find that the rheological properties emerging from these laboratory experiments can not be described in terms of preexisting governing models already presented in literature; our results indicate that neither rate–and state–dependent friction laws nor nonlinear slip–dependent models, commonly adopted for modeling earthquake ruptures, are able to capture all the features of the experimental data. Then, by exploiting a novel numerical approach, we directly incorporate the laboratory data into a code to simulate the fully dynamic propagation of a 3–D slip failure. We demonstrate that the rheology of the granular material, imposed as fault boundary condition, is dynamically consistent. Indeed, it is able to reproduce the basic features of a crustal earthquake, spontaneously accelerating up to some terminal rupture speed, both sub– and supershear.

Description: Published

Description: SE441

Description: 3T. Fisica dei terremoti e Sorgente Sismica

Description: JCR Journal

Description: INGV

Description: Published

Description: 1-18

Description: 1A. Geomagnetismo e Paleomagnetismo

Description: N/A or not JCR

Description: In the last decade, bottom-up strategies of risk education have raised importance, making seriousgames to become an alternative or complementary teaching tool for enhancing skills for acollaborative and adaptive response to social-ecological challenges. This study describes issues and challenges of serious games implemented within the framework oftwo European projects, namely UPStrat-MAFA (Urban Disaster Prevention Strategies usingMacroseismic Fields and FAult sources) and KnowRISK (Know your city, Reduce seISmic risKthrough non-structural elements); the goal is to instil in young people a proactive attitude towardsthe mitigation of seismic risk. The games were tested in some dissemination events focussed on fostering seismic riskpreparedness in students and improving good practices. We discuss the performance of our gameseven against more standard approaches to risk education. Our experience shows a rise of students’engagement compared to standard learning activities. The games were effective as students wereable to grasp the most relevant actions to reduce risk

Description: Published

Description: SE327

Description: 2TM. Divulgazione Scientifica

Description: JCR Journal

Description: A first combined absolute gravity and GNSS network of 5 stations distributed between Lazio, Umbria and Abruzzo regions, was realized in 2018 in order to lay the basics for a multidisciplinary approach to natural risk assessment in the area of Central Italy, affected by the 2009 and 2016 seismic activity. Up to now, two absolute gravity campaigns were carried out using the transportable Microg LaCoste FG5#238 and the portable A10#39 absolute gravimeters. The locations of gravimetric sites have been chosen indoor to allow optimal condition of measure; therefore, the heights of the indoor sites have been determined by joining the outdoor GNSS with classical topographic surveys. The good results obtained after the campaigns and data processing lay the foundations for a new multidisciplinary approach to study also seismogenetic areas. In this paper, we present the gravity and GNSS station monographs, together with the absolute gravity values and the coordinates resulting from the first field surveys.

Description: Published

Description: 1-26

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: Volcanic activity resumed during early Middle Ages times at Lipari following at least 6000 years of quiescence. This phenomenon occurred in a social context that had continuously developed from prehistoric times to the Roman age and was burdened by a demographic crisis that involved the archipelago between the 6th and 11th century AD. The rare archaeological records relating to the 6th - 11th centuries suggest abrupt changes in the population of the islands. The medieval sources are rich in religious and fantastic references to volcanic events linked to Lipari and Vulcano, testifying the uneasy condition for the human communities. This work concerns the resilience and adaptation of the communities to volcanic activity during the Late Middle Ages in Lipari. Starting from 1083 the Aeolian archipelago was involved in a repopulation program, implemented in 1095 by the Constitutum and organized by the Benedictine Monastery with the annexed S. Bartolomeo Cathedral on the castle. From the 13th century the volcanic phenomena, strictly limited to the northern sector of the island, did not interfere as previously with the anthropic activities. The Monastery will be enlarged in the Norman phase during the first half of the 12th century with the construction of the cloister. New historical documents relating to the 1264, report news of fires and land movements on Lipari. Recent age determinations obtained for the obsidian flow of Rocche Rosse at 1220 ± 30 AD (archaeomagnetic dating) and for an obsidian block of the Lami pyroclastic cone at 1243 ± 190 (fission-track dating) allow to define the age of the last phase of activity of the Monte Pilato-Lami-Rocche Rosse complex, and to associate it the events reported on 1264’s historical documents. This work makes in comparison volcanological, archaeological and historical dates and described an updated summary of one of the lesser known phases of the history of the archipelago. The main consequence of the medieval volcanic activity at Lipari caused a clear division of the territory with the population confined in the southeast quadrant, protected to the north by Serra and Monte Rosa which represented a natural orographic barrier.

Description: Published

Description: VO549

Description: 1V. Storia eruttiva

Description: JCR Journal

Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(6),(2022): 1191-1204, https://doi.org/10.1175/jpo-d-21-0242.1.

Description: A simplified quasigeostrophic (QG) analytical model together with an idealized numerical model are used to study the effect of uneven ice–ocean stress on the temporal evolution of the geostrophic current under sea ice. The tendency of the geostrophic velocity in the QG model is given as a function of the lateral gradient of vertical velocity and is further related to the ice–ocean stress with consideration of a surface boundary layer. Combining the analytical and numerical solutions, we demonstrate that the uneven stress between the ice and an initially surface-intensified, laterally sheared geostrophic current can drive an overturning circulation to trigger the displacement of isopycnals and modify the vertical structure of the geostrophic velocity. When the near-surface isopycnals become tilted in the opposite direction to the deeper ones, a subsurface velocity core is generated (via geostrophic setup). This mechanism should help understand the formation of subsurface currents in the edge of Chukchi and Beaufort Seas seen in observations. Furthermore, our solutions reveal a reversed flow extending from the bottom to the middepth, suggesting that the ice-induced overturning circulation potentially influences the currents in the deep layers of the Arctic Ocean, such as the Atlantic Water boundary current.

Description: This work was funded by the National Key Research and Development Program of China (Grant 2017YFA0604600), the National Natural Science Foundation of China (Grant 41676019), the Fundamental Research Funds for the Central Universities (Grant 2019B81214), the Postgraduate Research and Practice Innovation Program of Jiangsu Province (Grant KYCX19_0384), and the National Science Foundation (MAS, Grants OPP-1822334, OCE-2122633).

Description: For the phase refraction index of high frequency (HF) waves in the ionospheric medium exists a well-established theory. However, under the Quasi-Longitudinal (QL) conditions, scientific literature presents various formulas that are not equivalent and that, in some cases, give rise to wrong results. In the present study, further consequences of Booker's rule are discussed, illustrating the validity ranges of the above-mentioned approximate formulas; and the different regimes for applying such QL formulas are described, along with the consequences in simulating the ionospheric HF ray-tracing, oblique and vertical sounding, and absorption.

Description: Published

Description: PA003

Description: 2A. Fisica dell'alta atmosfera

Description: 7SR AMBIENTE – Servizi e ricerca per la società

Description: 3IT. Calcolo scientifico

Description: 7TM.Sviluppo e Trasferimento Tecnologico

Description: JCR Journal

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Renfrew, I. A., Pickart, R. S., Vage, K., Moore, G. W. K., Bracegirdle, T. J., Elvidge, A. D., Jeansson, E., Lachlan-Cope, T., McRaven, L. T., Papritz, L., Reuder, J., Sodemann, H., Terpstra, A., Waterman, S., Valdimarsson, H., Weiss, A., Almansi, M., Bahr, F., Brakstad, A., Barrell, C., Brooke, J. K., Brooks, B. J., Brooks, I. M., Brooks, M. E., Bruvik, E. M., Duscha, C., Fer, I., Golid, H. M., Hallerstig, M., Hessevik, I., Huang, J., Houghton, L., Jonsson, S., Jonassen, M., Jackson, K., Kvalsund, K., Kolstad, E. W., Konstali, K., Kristiansen, J., Ladkin, R., Lin, P., Macrander, A., Mitchell, A., Olafsson, H., Pacini, A., Payne, C., Palmason, B., Perez-Hernandez, M. D., Peterson, A. K., Petersen, G. N., Pisareva, M. N., Pope, J. O., Seidl, A., Semper, S., Sergeev, D., Skjelsvik, S., Soiland, H., Smith, D., Spall, M. A., Spengler, T., Touzeau, A., Tupper, G., Weng, Y., Williams, K. D., Yang, X., & Zhou, S. The Iceland Greenland Seas Project. Bulletin of the American Meteorological Society, 100(9), (2019): 1795-1817, doi:10.1175/BAMS-D-18-0217.1.

Description: The Iceland Greenland Seas Project (IGP) is a coordinated atmosphere–ocean research program investigating climate processes in the source region of the densest waters of the Atlantic meridional overturning circulation. During February and March 2018, a field campaign was executed over the Iceland and southern Greenland Seas that utilized a range of observing platforms to investigate critical processes in the region, including a research vessel, a research aircraft, moorings, sea gliders, floats, and a meteorological buoy. A remarkable feature of the field campaign was the highly coordinated deployment of the observing platforms, whereby the research vessel and aircraft tracks were planned in concert to allow simultaneous sampling of the atmosphere, the ocean, and their interactions. This joint planning was supported by tailor-made convection-permitting weather forecasts and novel diagnostics from an ensemble prediction system. The scientific aims of the IGP are to characterize the atmospheric forcing and the ocean response of coupled processes; in particular, cold-air outbreaks in the vicinity of the marginal ice zone and their triggering of oceanic heat loss, and the role of freshwater in the generation of dense water masses. The campaign observed the life cycle of a long-lasting cold-air outbreak over the Iceland Sea and the development of a cold-air outbreak over the Greenland Sea. Repeated profiling revealed the immediate impact on the ocean, while a comprehensive hydrographic survey provided a rare picture of these subpolar seas in winter. A joint atmosphere–ocean approach is also being used in the analysis phase, with coupled observational analysis and coordinated numerical modeling activities underway.

Description: The IGP has received funding from the U.S. National Science Foundation: Grant OCE-1558742; the U.K.’s Natural Environment Research Council: AFIS (NE/N009754/1); the Research Council of Norway: MOCN (231647), VENTILATE (229791), SNOWPACE (262710) and FARLAB (245907); and the Bergen Research Foundation (BFS2016REK01). We thank all those involved in the field work associated with the IGP, particularly the officers and crew of the Alliance, and the operations staff of the aircraft campaign.

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Giuffre, C., Hinow, P., Jiang, H., & Strickler, J. R. Oscillations in the near-field feeding current of a calanoid copepod are useful for particle sensing. Scientific Reports, 9(1), (2019): 17742, doi: 10.1038/s41598-019-54264-1.

Description: Calanoid copepods are small crustaceans that constitute a major element of aquatic ecosystems. Key to their success is their feeding apparatus consisting of sensor-studded mouth appendages that are in constant motion. These appendages generate a feeding current to enhance the encounter probability with food items. Additionally, sensing enables the organism to determine the position and quality of food particles, and to alter the near-field flow to capture and manipulate the particles for ingestion or rejection. Here we observe a freely swimming copepod Leptodiaptomus sicilis in multiple perspectives together with suspended particles that allow us to analyse the flow field created by the animal. We observe a highly periodic motion of the mouth appendages that is mirrored in oscillations of nearby tracer particles. We propose that the phase shift between the fluid and the particle velocities is sufficient for mechanical detection of the particles entrained in the feeding current. Moreover, we propose that an immersed algal cell may benefit from the excitation by increased uptake of dissolved inorganic compounds.

Description: We acknowledge funding from the Simons Foundation (grant #278436 to PH) during two visits of HJ to Milwaukee. HJ was also supported by NSF grant OCE-1559062. We thank Dr. Russell Cuhel (School of Freshwater Sciences, University of Wisconsin - Milwaukee) for collecting the animals from Lake Michigan and four unknown readers for valuable comments.

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Barry, P. H., Nakagawa, M., Giovannelli, D., de Moor, J. M., Schrenk, M., Seltzer, A. M., Manini, E., Fattorini, D., di Carlo, M., Regoli, F., Fullerton, K., & Lloyd, K. G. Helium, inorganic and organic carbon isotopes of fluids and gases across the Costa Rica convergent margin. Scientific Data, 6(1), (2019): 284, doi: 10.1038/s41597-019-0302-4.

Description: In 2017, fluid and gas samples were collected across the Costa Rican Arc. He and Ne isotopes, C isotopes as well as total organic and inorganic carbon concentrations were measured. The samples (n = 24) from 2017 are accompanied by (n = 17) samples collected in 2008, 2010 and 2012. He-isotopes ranged from arc-like (6.8 RA) to crustal (0.5 RA). Measured dissolved inorganic carbon (DIC) δ13CVPDB values varied from 3.55 to −21.57‰, with dissolved organic carbon (DOC) following the trends of DIC. Gas phase CO2 only occurs within ~20 km of the arc; δ13CVPDB values varied from −0.84 to −5.23‰. Onsite, pH, conductivity, temperature and dissolved oxygen (DO) were measured; pH ranged from 0.9–10.0, conductivity from 200–91,900 μS/cm, temperatures from 23–89 °C and DO from 2–84%. Data were used to develop a model which suggests that ~91 ± 4.0% of carbon released from the slab/mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition with an additional 3.3 ± 1.3% incorporated into autotrophic biomass.

Description: This work was principally supported by a grant (G-2016-7206) from the Alfred P. Sloan Foundation and the Deep Carbon Observatory to P.H.B. In addition, P.H.B. was supported by NSF grant 1144559 during a portion of this project. D.G. was supported by an NSF grant (MCB 15–17567) and an ELSI Origins Network (EON) research Fellowship, which is supported by a grant from the John Templeton Foundation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation. DG was also partially supported a Deep Life Modeling and Visualization Fellowship, which is supported by the Deep Carbon Observatory. This work was further supported in party by JSPS KAKENHI grants (JP17K14412, JP17H06105, JP17H02989) awarded to M.N., NSF OCE-1431598 and NASA Exobiology NNX16AL59G awarded to K.G.L. J.M.d.M. gratefully acknowledges funding from Universidad Nacional Costa Rica, the World Bank, and the Costa Rican Ley Transitorio 8933 used to acquire a laser carbon isotope system in collaboration with R. Sánchez-Murillo and G. Esquivel-Hernandez. M.N. produced the most data. We thank Patricia Barcala Dominguez for assistance with figure illustration. We thank Bruce Deck, Marten Wahlen and Keith Blackmon for analytical assistance at SIO. Finally, we acknowledge D. Hummer, T. Lopez, C.A. Pratt, Y. Alpízar Segura, A. Battaglia, P. Beaudry, G. Bini, M. Cascante, G. d’Errico, K. Fullerton, E. Gazel, G. González, S. A. Halldórsson, K. Iacovino, T. Ilanko, J.T. Kulongoski, M. Martínez, H. Miller, S. Ono, S. Patwardhan, C.J. Ramírez, F. Smedile, S. Turner, C. Vetriani, M. Yücel, C.J. Ballentine, T.P. Fischer, and D.R. Hilton, who were instrumental in proposal writing, sample collection, sample analysis and data analysis.

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chaput, D. L., Fowler, A. J., Seo, O., Duhn, K., Hansel, C. M., & Santelli, C. M. Mn oxide formation by phototrophs: spatial and temporal patterns, with evidence of an enzymatic superoxide-mediated pathway. Scientific Reports, 9(1), (2019): 18244, doi: 10.1038/s41598-019-54403-8.

Description: Manganese (Mn) oxide minerals influence the availability of organic carbon, nutrients and metals in the environment. Oxidation of Mn(II) to Mn(III/IV) oxides is largely promoted by the direct and indirect activity of microorganisms. Studies of biogenic Mn(II) oxidation have focused on bacteria and fungi, with phototrophic organisms (phototrophs) being generally overlooked. Here, we isolated phototrophs from Mn removal beds in Pennsylvania, USA, including fourteen Chlorophyta (green algae), three Bacillariophyta (diatoms) and one cyanobacterium, all of which consistently formed Mn(III/IV) oxides. Isolates produced cell-specific oxides (coating some cells but not others), diffuse biofilm oxides, and internal diatom-specific Mn-rich nodules. Phototrophic Mn(II) oxidation had been previously attributed to abiotic oxidation mediated by photosynthesis-driven pH increases, but we found a decoupling of Mn oxide formation and pH alteration in several cases. Furthermore, cell-free filtrates of some isolates produced Mn oxides at specific time points, but this activity was not induced by Mn(II). Manganese oxide formation in cell-free filtrates occurred via reaction with the oxygen radical superoxide produced by soluble extracellular proteins. Given the known widespread ability of phototrophs to produce superoxide, the contribution of phototrophs to Mn(II) oxidation in the environment may be greater and more nuanced than previously thought.

Description: This work was funded by a Smithsonian Scholarly Studies grant to CMS, by a Smithsonian Postdoctoral Fellowship to DLC, by the National Science Foundation, grant number CBET-1336496, to CMH and CMS, and by MnDRIVE Environment at the University of Minnesota to CMS. We thank Margaret Dunn and Cliff Denholm, Stream Restoration Inc., for assistance and access to field sites, Carolyn Zeiner (WHOI/Harvard) for useful discussions and advice regarding ROS experiments, as well as Jeff Post, Tim Rose and Tim Gooding (Smithsonian NMNH) for assistance with the SEM/EDS work. Portions of the laboratory work were conducted in and with the support of the L.A.B. facilities at the National Museum of Natural History, Smithsonian Institution.

Description: Author Posting. © American Meteorological Society, 2019. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 49(12), (2019): 3127-3143, doi: 10.1175/JPO-D-19-0011.1.

Description: The Intermediate Western Boundary Current (IWBC) transports Antarctic Intermediate Water across the Vitória–Trindade Ridge (VTR), a seamount chain at ~20°S off Brazil. Recent studies suggest that the IWBC develops a strong cyclonic recirculation in Tubarão Bight, upstream of the VTR, with weak time dependency. We herein use new quasi-synoptic observations, data from the Argo array, and a regional numerical model to describe the structure and variability of the IWBC and to investigate its dynamics. Both shipboard acoustic Doppler current profiler (ADCP) data and trajectories of Argo floats confirm the existence of the IWBC recirculation, which is also captured by our Regional Oceanic Modeling System (ROMS) simulation. An “intermediate-layer” quasigeostrophic (QG) model indicates that the ROMS time-mean flow is a good proxy for the IWBC steady state, as revealed by largely parallel isolines of streamfunction ψ⎯ and potential vorticity Q⎯; a ψ⎯−Q⎯ scatter diagram also shows that the IWBC is potentially unstable. Further analysis of the ROMS simulation reveals that remotely generated, westward-propagating nonlinear eddies are the main source of variability in the region. These eddies enter the domain through the Tubarão Bight eastern edge and strongly interact with the IWBC. As they are advected downstream and negotiate the local topography, the eddies grow explosively through horizontal shear production.

Description: We thank Frank O. Smith for copy editing and proofreading this manuscript. This study was financed in part by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—CAPES, Brazil—Finance Code 001 and by Projeto REMARSUL (Processo CAPES 88882.158621/2014-01), Projeto VT-Dyn (Processo FAPESP 2015/21729-4) and Projeto SUBMESO (Processo CNPq 442926/2015-4). Rocha was supported by a WHOI Postdoctoral Scholarship.

Description: 2020-06-06

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kwon, Y., Seo, H., Ummenhofer, C. C., & Joyce, T. M. Impact of multidecadal variability in Atlantic SST on winter atmospheric blocking. Journal of Climate, 33(3), (2020): 867-892, doi: 10.1175/JCLI-D-19-0324.1.

Description: Recent studies have suggested that coherent multidecadal variability exists between North Atlantic atmospheric blocking frequency and the Atlantic multidecadal variability (AMV). However, the role of AMV in modulating blocking variability on multidecadal times scales is not fully understood. This study examines this issue primarily using the NOAA Twentieth Century Reanalysis for 1901–2010. The second mode of the empirical orthogonal function for winter (December–March) atmospheric blocking variability in the North Atlantic exhibits oppositely signed anomalies of blocking frequency over Greenland and the Azores. Furthermore, its principal component time series shows a dominant multidecadal variability lagging AMV by several years. Composite analyses show that this lag is due to the slow evolution of the AMV sea surface temperature (SST) anomalies, which is likely driven by the ocean circulation. Following the warm phase of AMV, the warm SST anomalies emerge in the western subpolar gyre over 3–7 years. The ocean–atmosphere interaction over these 3–7-yr periods is characterized by the damping of the warm SST anomalies by the surface heat flux anomalies, which in turn reduce the overall meridional gradient of the air temperature and thus weaken the meridional transient eddy heat flux in the lower troposphere. The anomalous transient eddy forcing then shifts the eddy-driven jet equatorward, resulting in enhanced Rossby wave breaking and blocking on the northern flank of the jet over Greenland. The opposite is true with the AMV cold phases but with much shorter lags, as the evolution of SST anomalies differs in the warm and cold phases.

Description: We gratefully acknowledge support from the NSF Climate and Large-scale Dynamics Program (AGS-1355339) to Y-OK, HS, CCU, and TMJ, the NASA Physical Oceanography Program (NNX13AM59G) to Y-OK, HS, and TMJ, NOAA CPO Climate Variability and Predictability Program (NA13OAR4310139) and DOE CESD Regional and Global Model Analysis Program (DE-SC0019492) to Y-OK, and NSF Physical Oceanography Program (OCE-1419235) to HS. We are very grateful to the three anonymous reviewers and editor Dr. Mingfang Ting, for their thorough and insightful suggestions. The NOAA 20CR dataset was downloaded from the NOAA Earth System Research Laboratory Physical Science Division webpage (https://www.esrl.noaa.gov/psd/data/20thC_Rean/). Support for the 20CR Project version 2c dataset is provided by the U.S. Department of Energy, Office of Science Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office. The HadISST dataset was downloaded from the U.K. Met Office Hadley Centre webpage (https://www.metoffice.gov.uk/hadobs/hadisst/). The ERA-20C dataset was downloaded from the ECMWF webpage (https://apps.ecmwf.int/datasets/data/era20c-daily/). The ERSST5 dataset was provided by the NOAA Earth System Research Laboratory Physical Science Division (https://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.v5.html).

Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ciacci, C., Grimmelpont, M. V., Corsi, I., Bergami, E., Curzi, D., Burini, D., Bouchet, V. M. P., Ambrogini, P., Gobbi, P., Ujiié, Y., Ishitani, Y., Coccioni, R., Bernhard, J. M., & Frontalini, F. Nanoparticle-biological interactions in a marine benthic foraminifer. Scientific Reports, (91), (2019): 19441, doi:10.1038/s41598-019-56037-2.

Description: The adverse effects of engineered nanomaterials (ENM) in marine environments have recently attracted great attention although their effects on marine benthic organisms such as foraminifera are still largely overlooked. Here we document the effects of three negatively charged ENM, different in size and composition, titanium dioxide (TiO2), polystyrene (PS) and silicon dioxide (SiO2), on a microbial eukaryote (the benthic foraminifera Ammonia parkinsoniana) using multiple approaches. This research clearly shows the presence, within the foraminiferal cytoplasm, of metallic (Ti) and organic (PS) ENM that promote physiological stress. Specifically, marked increases in the accumulation of neutral lipids and enhanced reactive oxygen species production occurred in ENM-treated specimens regardless of ENM type. This study indicates that ENM represent ecotoxicological risks for this microbial eukaryote and presents a new model for the neglected marine benthos by which to assess natural exposure scenarios.

Description: The authors are very grateful to two anonymous reviewers for their thoughtful and valuable comments that have greatly improved our contribution. NP characterization by DLS was conducted at the facilities of the Department of Biotechnologies, Chemistry and Pharmacy of the University of Siena (Italy). The authors acknowledge Prof. Andrea M. Atrei for the support in DLS analysis. Margot V. Grimmelpont’s stay at Urbino University was supported by an ERASMUS + fellowship.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(2), (2020): 415-437, doi:10.1175/JPO-D-19-0019.1.

Description: Results are presented from two dye release experiments conducted in the seasonal thermocline of the Sargasso Sea, one in a region of low horizontal strain rate (~10−6 s−1), the second in a region of intermediate horizontal strain rate (~10−5 s−1). Both experiments lasted ~6 days, covering spatial scales of 1–10 and 1–50 km for the low and intermediate strain rate regimes, respectively. Diapycnal diffusivities estimated from the two experiments were κz = (2–5) × 10−6 m2 s−1, while isopycnal diffusivities were κH = (0.2–3) m2 s−1, with the range in κH being less a reflection of site-to-site variability, and more due to uncertainties in the background strain rate acting on the patch combined with uncertain time dependence. The Site I (low strain) experiment exhibited minimal stretching, elongating to approximately 10 km over 6 days while maintaining a width of ~5 km, and with a notable vertical tilt in the meridional direction. By contrast, the Site II (intermediate strain) experiment exhibited significant stretching, elongating to more than 50 km in length and advecting more than 150 km while still maintaining a width of order 3–5 km. Early surveys from both experiments showed patchy distributions indicative of small-scale stirring at scales of order a few hundred meters. Later surveys show relatively smooth, coherent distributions with only occasional patchiness, suggestive of a diffusive rather than stirring process at the scales of the now larger patches. Together the two experiments provide important clues as to the rates and underlying processes driving diapycnal and isopycnal mixing at these scales.

Description: Results are presented from two dye release experiments conducted in the seasonal thermocline of the Sargasso Sea, one in a region of low horizontal strain rate (~10−6 s−1), the second in a region of intermediate horizontal strain rate (~10−5 s−1). Both experiments lasted ~6 days, covering spatial scales of 1–10 and 1–50 km for the low and intermediate strain rate regimes, respectively. Diapycnal diffusivities estimated from the two experiments were κz = (2–5) × 10−6 m2 s−1, while isopycnal diffusivities were κH = (0.2–3) m2 s−1, with the range in κH being less a reflection of site-to-site variability, and more due to uncertainties in the background strain rate acting on the patch combined with uncertain time dependence. The Site I (low strain) experiment exhibited minimal stretching, elongating to approximately 10 km over 6 days while maintaining a width of ~5 km, and with a notable vertical tilt in the meridional direction. By contrast, the Site II (intermediate strain) experiment exhibited significant stretching, elongating to more than 50 km in length and advecting more than 150 km while still maintaining a width of order 3–5 km. Early surveys from both experiments showed patchy distributions indicative of small-scale stirring at scales of order a few hundred meters. Later surveys show relatively smooth, coherent distributions with only occasional patchiness, suggestive of a diffusive rather than stirring process at the scales of the now larger patches. Together the two experiments provide important clues as to the rates and underlying processes driving diapycnal and isopycnal mixing at these scales.

Description: 2020-08-06

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 37(5), (2020): 789-806, doi:10.1175/JTECH-D-18-0244.1.

Description: Realistic ocean state prediction and its validation rely on the availability of high quality in situ observations. To detect data errors, adequate quality check procedures must be designed. This paper presents procedures that take advantage of the ever-growing observation databases that provide climatological knowledge of the ocean variability in the neighborhood of an observation location. Local validity intervals are used to estimate binarily whether the observed values are considered as good or erroneous. Whereas a classical approach estimates validity bounds from first- and second-order moments of the climatological parameter distribution, that is, mean and variance, this work proposes to infer them directly from minimum and maximum observed values. Such an approach avoids any assumption of the parameter distribution such as unimodality, symmetry around the mean, peakedness, or homogeneous distribution tail height relative to distribution peak. To reach adequate statistical robustness, an extensive manual quality control of the reference dataset is critical. Once the data have been quality checked, the local minima and maxima reference fields are derived and the method is compared with the classical mean/variance-based approach. Performance is assessed in terms of statistics of good and bad detections. It is shown that the present size of the reference datasets allows the parameter estimates to reach a satisfactory robustness level to always make the method more efficient than the classical one. As expected, insufficient robustness persists in areas with an especially low number of samples and high variability.

Description: This study has been conducted using EU Copernicus Marine Service Information and was supported by the European Union within the EU Copernicus Marine Service In Situ phase-I and phase-II contracts led by Ifremer. The publication was also supported by SOERE CTDO2 in France. The Argo data were collected and made freely available by the International Argo Program and the national programs that contribute to it (see http://www.argo.ucsd.edu, http://argo.jcommops.org). The Argo Program is part of the Global Ocean Observing System (http://doi.org/10.17882/42182). The marine mammal data were collected and made freely available by the International MEOP Consortium and the national programs that contribute to it (see http://www.meop.net; https://doi.org/10.17882/45461). Aleix Gelabert and Dídac Costa were the skippers of the OPOO, sponsored by the Intergovernmental Oceanographic Commission (UNESCO) and Pharmaton. The BWR is a periodic oceanic race organized by the Fundació Navegació Oceànica de Barcelona (FNOB). Reviewer D. Briand provided some useful comments on the final version of the draft paper before submission.

Description: 2020-11-04

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(5), (2020): 1245-1263, doi:10.1175/JPO-D-19-0213.1.

Description: We use laboratory experiments and theoretical modeling to investigate the surface expression of a subglacial discharge plume, as occurs at many fjords around Greenland. The experiments consider a fountain that is released vertically into a homogeneous fluid, adjacent either to a vertical or a sloping wall, that then spreads horizontally at the free surface before sinking back to the bottom. We present a model that separates the fountain into two separate regions: a vertical fountain and a horizontal, negatively buoyant jet. The model is compared to laboratory experiments that are conducted over a range of volume fluxes, density differences, and ambient fluid depths. It is shown that the nondimensionalized length, width, and aspect ratio of the surface expression are dependent on the Froude number, calculated at the start of the negatively buoyant jet. The model is applied to observations of the surface expression from a Greenland subglacial discharge plume. In the case where the discharge plume reaches the surface with negative buoyancy the model can be used to estimate the discharge properties at the base of the glacier.

Description: We gratefully acknowledge technical assistance from Anders Jensen and thank anonymous reviewers for improving the clarity of the manuscript. CM thanks the Weston Howard Jr. Scholarship for funding. Support to CC was given by NSF project OCE-1434041 and OCE-1658079.

Description: 2020-10-27

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marzen, R. E., Shillington, D. J., Lizarralde, D., Knapp, J. H., Heffner, D. M., Davis, J. K., & Harder, S. H. Limited and localized magmatism in the Central Atlantic Magmatic Province. Nature Communications, 11(1), (2020): 3397, doi:10.1038/s41467-020-17193-6.

Description: The Central Atlantic Magmatic Province (CAMP) is the most aerially extensive magmatic event in Earth’s history, but many questions remain about its origin, volume, and distribution. Despite many observations of CAMP magmatism near Earth’s surface, few constraints exist on CAMP intrusions at depth. Here we present detailed constraints on crustal and upper mantle structure from wide-angle seismic data across the Triassic South Georgia Rift that formed shortly before CAMP. Lower crustal magmatism is concentrated where synrift sedimentary fill is thickest and the crust is thinnest, suggesting that lithospheric thinning influenced the locus and volume of magmatism. The limited distribution of lower crustal intrusions implies modest total CAMP volumes of 85,000 to 169,000 km3 beneath the South Georgia Rift, consistent with moderately elevated mantle potential temperatures (〈1500 °C). These results suggest that CAMP magmatism in the South Georgia Rift is caused by syn-rift decompression melting of a warm, enriched mantle.

Description: This project was funded by an NSF GRFP fellowship DGE 16-44869 and a grant from the National Science Foundation’s Division of Earth Sciences (NSF-EAR) EarthScope program through the collaborative awards EAR-1144534/−1144829/−1144391. Data collection was made possible with help from IRIS PASSCAL, the University of Texas El Paso Seismic Source Facility, the teams of students who deployed and recovered geophones, and the support of landowners and county and state officials. We thank Alistair Harding for the VMTomo code, Nathan Miller for the PyVM toolbox, and William Wilcock for maintaining the Upicker package to pick arrivals.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(3), (2020): 679-694, doi:10.1175/JPO-D-19-0218.1.

Description: The zonally integrated flow in a basin can be separated into the divergent/nondivergent parts, and a uniquely defined meridional overturning circulation (MOC) can be calculated. For a basin with significant volume exchange at zonal open boundaries, this method is competent in removing the components associated with the nonzero source terms due to zonal transports at open boundaries. This method was applied to the zonally integrated flow in the Indian Ocean basin extended all the way to the Antarctic by virtue of the ECCO dataset. The contributions due to two major zonal flow systems at open boundaries, the Indonesian Throughflow (ITF) and the Antarctic Circumpolar Current (ACC), were well separated from the rotational flow component, and a nondivergent overturning circulation pattern was identified. Comparisons with previous studies on the MOC of the Indian Ocean in different seasons showed overall consistency but with refinements in details to the south of the entry of the ITF, reflecting the influence of ITF on the MOC pattern in the domain. Other options of decomposition are also examined.

Description: LH was supported by the National Basic Research Program of China through Grant 2019YFA0606703 and “The Fundamental Research Funds of Shandong University” (2019GN051). The authors thank the anonymous reviewers and the editor for their constructive comments. Code availability: The Matlab code that performs the decomposition and produces some figures in this paper is available at https://github.com/lei-han-SDU/IMOC/.

Description: 2020-09-02

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Domeignoz-Horta, L. A., Pold, G., Liu, X. A., Frey, S. D., Melillo, J. M., & DeAngelis, K. M. Microbial diversity drives carbon use efficiency in a model soil. Nature Communications, 11(1), (2020): 3684, doi:10.1038/s41467-020-17502-z.

Description: Empirical evidence for the response of soil carbon cycling to the combined effects of warming, drought and diversity loss is scarce. Microbial carbon use efficiency (CUE) plays a central role in regulating the flow of carbon through soil, yet how biotic and abiotic factors interact to drive it remains unclear. Here, we combine distinct community inocula (a biotic factor) with different temperature and moisture conditions (abiotic factors) to manipulate microbial diversity and community structure within a model soil. While community composition and diversity are the strongest predictors of CUE, abiotic factors modulated the relationship between diversity and CUE, with CUE being positively correlated with bacterial diversity only under high moisture. Altogether these results indicate that the diversity × ecosystem-function relationship can be impaired under non-favorable conditions in soils, and that to understand changes in soil C cycling we need to account for the multiple facets of global changes.

Description: Funding for this project was provided by the Department of Energy grant DE-SC0016590 to K.M.D. and S.D.F., and an American Association of University Women Dissertation fellowship to G.P. We would also like to thank Stuart Grandy and Kevin Geyer for the fruitful discussions and Mary Waters, Courtney Bly and Ana Horta for their help with samples processing.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Tao, C., Seyfried, W. E., Jr., Lowell, R. P., Liu, Y., Liang, J., Guo, Z., Ding, K., Zhang, H., Liu, J., Qiu, L., Egorov, I., Liao, S., Zhao, M., Zhou, J., Deng, X., Li, H., Wang, H., Cai, W., Zhang, G., Zhou, H., Lin, J., & Li, W. Deep high-temperature hydrothermal circulation in a detachment faulting system on the ultra-slow spreading ridge. Nature Communications, 11(1), (2020): 1300, doi:10.1038/s41467-020-15062-w.

Description: Coupled magmatic and tectonic activity plays an important role in high-temperature hydrothermal circulation at mid-ocean ridges. The circulation patterns for such systems have been elucidated by microearthquakes and geochemical data over a broad spectrum of spreading rates, but such data have not been generally available for ultra-slow spreading ridges. Here we report new geophysical and fluid geochemical data for high-temperature active hydrothermal venting at Dragon Horn area (49.7°E) on the Southwest Indian Ridge. Twin detachment faults penetrating to the depth of 13 ± 2 km below the seafloor were identified based on the microearthquakes. The geochemical composition of the hydrothermal fluids suggests a long reaction path involving both mafic and ultramafic lithologies. Combined with numerical simulations, our results demonstrate that these hydrothermal fluids could circulate ~ 6 km deeper than the Moho boundary and to much greater depths than those at Trans-Atlantic Geotraverse and Logachev-1 hydrothermal fields on the Mid-Atlantic Ridge.

Description: This work was supported by National Key R&D Program of China under contract no. 2018YFC0309901, 2017YFC0306603, 2017YFC0306803, and 2017YFC0306203, COMRA Major Project under contract No. DY135-S1-01-01 and No. DY135-S1-01-06.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Bajnai, D., Guo, W., Spötl, C., Coplen, T. B., Methner, K., Löffler, N., Krsnik, E., Gischler, E., Hansen, M., Henkel, D., Price, G. D., Raddatz, J., Scholz, D., & Fiebig, J. Dual clumped isotope thermometry resolves kinetic biases in carbonate formation temperatures. Nature Communications, 11(1), (2020): 4005, doi:10.1038/s41467-020-17501-0.

Description: Surface temperature is a fundamental parameter of Earth’s climate. Its evolution through time is commonly reconstructed using the oxygen isotope and the clumped isotope compositions of carbonate archives. However, reaction kinetics involved in the precipitation of carbonates can introduce inaccuracies in the derived temperatures. Here, we show that dual clumped isotope analyses, i.e., simultaneous ∆47 and ∆48 measurements on the single carbonate phase, can identify the origin and quantify the extent of these kinetic biases. Our results verify theoretical predictions and evidence that the isotopic disequilibrium commonly observed in speleothems and scleractinian coral skeletons is inherited from the dissolved inorganic carbon pool of their parent solutions. Further, we show that dual clumped isotope thermometry can achieve reliable palaeotemperature reconstructions, devoid of kinetic bias. Analysis of a belemnite rostrum implies that it precipitated near isotopic equilibrium and confirms the warmer-than-present temperatures during the Early Cretaceous at southern high latitudes.

Description: This work became possible through DFG grant “INST 161/871-1” and the Investment in Science Fund at Woods Hole Oceanographic Institution. The authors would like to thank Sven Hofmann and Manuel Schumann for their assistance in the joint Goethe University – Senckenberg BiK-F Stable Isotope Facility at the Institute of Geosciences, Goethe University Frankfurt. K.M. acknowledges funding through “DFG ME 4955/1-1”, E.K. through “DFG MU 2845/6-1”, D.S. through “DFG SCHO 1274/8-1” and “DFG SCHO 1274/11-1”, and M.H. through “DFG HA 8694/1-1”. C.S. acknowledges funding from the University of Innsbruck. A review of the manuscript by David Evans on behalf of the USGS is acknowledged.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Rodysill, J. R., Donnelly, J. P., Sullivan, R., Lane, P. D., Toomey, M., Woodruff, J. D., Hawkes, A. D., MacDonald, D., d'Entremont, N., McKeon, K., Wallace, E., & van Hengstum, P. J. Historically unprecedented Northern Gulf of Mexico hurricane activity from 650 to 1250 CE. Scientific Reports, 10(1), (2020): 19092. doi:10.1038/s41598-020-75874-0.

Description: Hurricane Michael (2018) was the first Category 5 storm on record to make landfall on the Florida panhandle since at least 1851 CE (Common Era), and it resulted in the loss of 59 lives and $25 billion in damages across the southeastern U.S. This event placed a spotlight on recent intense (exceeding Category 4 or 5 on the Saffir-Simpson Hurricane Wind Scale) hurricane landfalls, prompting questions about the natural range in variability of hurricane activity that the instrumental record is too short to address. Of particular interest is determining whether the frequency of recent intense hurricane landfalls in the northern Gulf of Mexico (GOM) is within or outside the natural range of intense hurricane activity prior to 1851 CE. In this study, we identify intense hurricane landfalls in northwest Florida during the past 2000 years based on coarse anomaly event detection from two coastal lacustrine sediment archives. We identified a historically unprecedented period of heightened storm activity common to four Florida panhandle localities from 650 to 1250 CE and a shift to a relatively quiescent storm climate in the GOM spanning the past six centuries. Our study provides long-term context for events like Hurricane Michael and suggests that the observational period 1851 CE to present may underrepresent the natural range in landfalling hurricane activity.

Description: Funding for this project was provided by the Strategic Environmental Research and Development Program (SERDP) grant and NSF awards 0903020, 1902463, and 1854980 awarded to Jeffrey Donnelly, and the USGS Land Change Science Program.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kennedy, E. B. L., Buresch, K. C., Boinapally, P., & Hanlon, R. T. Octopus arms exhibit exceptional flexibility. Scientific Reports, 10(1), (2020): 20872. doi:10.1038/s41598-020-77873-7.

Description: The octopus arm is often referred to as one of the most flexible limbs in nature, yet this assumption requires detailed inspection given that this has not been measured comprehensively for all portions of each arm. We investigated the diversity of arm deformations in Octopus bimaculoides with a frame-by-frame observational analysis of laboratory video footage in which animals were challenged with different tasks. Diverse movements in these hydrostatic arms are produced by some combination of four basic deformations: bending (orally, aborally; inward, outward), torsion (clockwise, counter-clockwise), elongation, and shortening. More than 16,500 arm deformations were observed in 120 min of video. Results showed that all eight arms were capable of all four types of deformation along their lengths and in all directions. Arms function primarily to bring the sucker-lined oral surface in contact with target surfaces. Bending was the most common deformation observed, although the proximal third of the arms performed relatively less bending and more shortening and elongation as compared with other arm regions. These findings demonstrate the exceptional flexibility of the octopus arm and provide a basis for investigating motor control of the entire arm, which may aid the future development of soft robotics.

Description: We gratefully acknowledge funding from Grant N00014-19-1-2445 from the Office of Naval Research, Tom McKenna and Marc Steinberg, Program Managers. We also thank the staff of the Marine Resources Center at MBL for assistance with water quality measurements, seawater system maintenance, and collection of food items for octopuses.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Naert, T., Tulkens, D., Edwards, N. A., Carron, M., Shaidani, N. I., Wlizla, M., Boel, A., Demuynck, S., Horb, M. E., Coucke, P., Willaert, A., Zorn, A. M., & Vleminckx, K. Maximizing CRISPR/Cas9 phenotype penetrance applying predictive modeling of editing outcomes in Xenopus and zebrafish embryos. Scientific Reports, 10(1), (2020): 14662, doi:10.1038/s41598-020-71412-0.

Description: CRISPR/Cas9 genome editing has revolutionized functional genomics in vertebrates. However, CRISPR/Cas9 edited F0 animals too often demonstrate variable phenotypic penetrance due to the mosaic nature of editing outcomes after double strand break (DSB) repair. Even with high efficiency levels of genome editing, phenotypes may be obscured by proportional presence of in-frame mutations that still produce functional protein. Recently, studies in cell culture systems have shown that the nature of CRISPR/Cas9-mediated mutations can be dependent on local sequence context and can be predicted by computational methods. Here, we demonstrate that similar approaches can be used to forecast CRISPR/Cas9 gene editing outcomes in Xenopus tropicalis, Xenopus laevis, and zebrafish. We show that a publicly available neural network previously trained in mouse embryonic stem cell cultures (InDelphi-mESC) is able to accurately predict CRISPR/Cas9 gene editing outcomes in early vertebrate embryos. Our observations can have direct implications for experiment design, allowing the selection of guide RNAs with predicted repair outcome signatures enriched towards frameshift mutations, allowing maximization of CRISPR/Cas9 phenotype penetrance in the F0 generation.

Description: Research in the Vleminckx laboratory is supported by the Research Foundation—Flanders (FWO-Vlaanderen) (Grants G0A1515N and G029413N), by the Belgian Science Policy (Interuniversity Attraction Poles—IAP7/07) and by the Concerted Research Actions from Ghent University (BOF15/GOA/011). Further support was obtained by the Hercules Foundation, Flanders (Grant AUGE/11/14) and the Desmoid Tumor Research Foundation and the Desmoid Tumour Foundation Canada. T.N. is funded by “Kom op tegen Kanker” (Stand up to Cancer), the Flemish cancer society and previously held PhD fellowship with VLAIO-HERMES during the course of this work. D.T. and M. C. hold a PhD fellowship from the Research Foundation-Flanders (FWO-Vlaanderen). The Zorn Lab is supported by Funding from NIH National Institute of Child Health and Human Development (NICHD) P01 HD093363. A.W. and A.B. are supported by the Ghent University (Universiteit Gent) Methusalem grant BOFMET2015000401 to Anne De Paepe. The National Xenopus Resource and Horb lab is supported by funding from the National Institutes of Health (P40 OD010997 and R01 HD084409).

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(9), (2020): 2491-2506, doi:10.1175/JPO-D-20-0056.1.

Description: An idealized two-layer shallow water model is applied to the study of the dynamics of the Arctic Ocean halocline. The model is forced by a surface stress distribution reflective of the observed wind stress pattern and ice motion and by an inflow representing the flow of Pacific Water through Bering Strait. The model reproduces the main elements of the halocline circulation: an anticyclonic Beaufort Gyre in the western basin (representing the Canada Basin), a cyclonic circulation in the eastern basin (representing the Eurasian Basin), and a Transpolar Drift between the two gyres directed from the upwind side of the basin to the downwind side of the basin. Analysis of the potential vorticity budget shows a basin-averaged balance primarily between potential vorticity input at the surface and dissipation at the lateral boundaries. However, advection is a leading-order term not only within the anticyclonic and cyclonic gyres but also between the gyres. This means that the eastern and western basins are dynamically connected through the advection of potential vorticity. Both eddy and mean fluxes play a role in connecting the regions of potential vorticity input at the surface with the opposite gyre and with the viscous boundary layers. These conclusions are based on a series of model runs in which forcing, topography, straits, and the Coriolis parameter were varied.

Description: This study was supported by National Science Foundation Grant OPP-1822334. Comments and suggestions from two anonymous referees greatly helped to improve the paper.

Description: 2021-02-17

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Boissin, E., Neglia, V., Baksay, S., Micu, D., Bat, L., Topaloglu, B., Todorova, V., Panayotova, M., Kruschel, C., Milchakova, N., Voutsinas, E., Beqiraj, S., Nasto, I., Aglieri, G., Taviani, M., Zane, L., & Planes, S. Chaotic genetic structure and past demographic expansion of the invasive gastropod Tritia neritea in its native range, the Mediterranean Sea. Scientific Reports, 10(1), (2020): 21624. doi:10.1038/s41598-020-77742-3.

Description: To better predict population evolution of invasive species in introduced areas it is critical to identify and understand the mechanisms driving genetic diversity and structure in their native range. Here, we combined analyses of the mitochondrial COI gene and 11 microsatellite markers to investigate both past demographic history and contemporaneous genetic structure in the native area of the gastropod Tritia neritea, using Bayesian skyline plots (BSP), multivariate analyses and Bayesian clustering. The BSP framework revealed population expansions, dated after the last glacial maximum. The haplotype network revealed a strong geographic clustering. Multivariate analyses and Bayesian clustering highlighted the strong genetic structure at all scales, between the Black Sea and the Adriatic Sea, but also within basins. Within basins, a random pattern of genetic patchiness was observed, suggesting a superimposition of processes involving natural biological effects (no larval phase and thus limited larval dispersal) and putative anthropogenic transport of specimens. Contrary to the introduced area, no isolation-by-distance patterns were recovered in the Mediterranean or the Black Seas, highlighting different mechanisms at play on both native and introduced areas, triggering unknown consequences for species’ evolutionary trajectories. These results of Tritia neritea populations on its native range highlight a mixture of ancient and recent processes, with the effects of paleoclimates and life history traits likely tangled with the effects of human-mediated dispersal.

Description: This project was funded by the European FP7 CoCoNet project (Ocean.2011-4, grant agreement #287844) and we are grateful to the whole CoCoNET consortium. We are grateful to the following people for their critical help with logistics and field work ‘Antheus srl (Lecce, Italy)’; S Bevilacqua, G Guarnieri, S Fraschetti and T Terlizzi (University of Salento, Italy); L Angeletti and M Sigovini (ISMAR, Italy); D Shamrey (IBSS, Sevastopol); A Anastasopoulou, MA Pancucci-Papadopoulou and S Reizopoulou (HCMR, Greece) and E Hajdëri (Catholic University ‘Our Lady of Good Counsel’, Tirana). Thank you to J Almany for English corrections. This is ISMAR-CNR scientific contribution n1987. E Boissin was supported by a European Marie Curie postdoctoral fellowship MC-CIG-618480.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 101(6), (2020): E897-E904, doi:10.1175/BAMS-D-19-0047.1.

Description: Over the past 15 years, numerous studies have suggested that the sinking branches of Earth’s Hadley circulation and the associated subtropical dry zones have shifted poleward over the late twentieth century and early twenty-first century. Early estimates of this tropical widening from satellite observations and reanalyses varied from 0.25° to 3° latitude per decade, while estimates from global climate models show widening at the lower end of the observed range. In 2016, two working groups, the U.S. Climate Variability and Predictability (CLIVAR) working group on the Changing Width of the Tropical Belt and the International Space Science Institute (ISSI) Tropical Width Diagnostics Intercomparison Project, were formed to synthesize current understanding of the magnitude, causes, and impacts of the recent tropical widening evident in observations. These working groups concluded that the large rates of observed tropical widening noted by earlier studies resulted from their use of metrics that poorly capture changes in the Hadley circulation, or from the use of reanalyses that contained spurious trends. Accounting for these issues reduces the range of observed expansion rates to 0.25°–0.5° latitude decade‒1—within the range from model simulations. Models indicate that most of the recent Northern Hemisphere tropical widening is consistent with natural variability, whereas increasing greenhouse gases and decreasing stratospheric ozone likely played an important role in Southern Hemisphere widening. Whatever the cause or rate of expansion, understanding the regional impacts of tropical widening requires additional work, as different forcings can produce different regional patterns of widening.

Description: We thank U.S. CLIVAR and ISSI for funding the two working groups. We thank all members of the working groups for helpful discussions, and the U.S. CLIVAR and ISSI offices and their sponsoring agencies (NASA, NOAA, NSF, DOE, ESA, Swiss Confederation, Swiss Academy of Sciences, and University of Bern) for supporting these groups and activities.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Liu, D., Ma, Q., Valiela, I., Anderson, D. M., Keesing, J. K., Gao, K., Zhen, Y., Sun, X., & Wang, Y. Role of C4 carbon fixation in Ulva prolifera, the macroalga responsible for the world's largest green tides. Communications Biology, 3(1), (2020): 494, doi:10.1038/s42003-020-01225-4.

Description: Most marine algae preferentially assimilate CO2 via the Calvin-Benson Cycle (C3) and catalyze HCO3− dehydration via carbonic anhydrase (CA) as a CO2-compensatory mechanism, but certain species utilize the Hatch-Slack Cycle (C4) to enhance photosynthesis. The occurrence and importance of the C4 pathway remains uncertain, however. Here, we demonstrate that carbon fixation in Ulva prolifera, a species responsible for massive green tides, involves a combination of C3 and C4 pathways, and a CA-supported HCO3− mechanism. Analysis of CA and key C3 and C4 enzymes, and subsequent analysis of δ13C photosynthetic products showed that the species assimilates CO2 predominately via the C3 pathway, uses HCO3− via the CA mechanism at low CO2 levels, and takes advantage of high irradiance using the C4 pathway. This active and multi-faceted carbon acquisition strategy is advantageous for the formation of massive blooms, as thick floating mats are subject to intense surface irradiance and CO2 limitation.

Description: This work was supported by the State Key Project of Research and Development Plan, Ministry of Science and Technology of the Peopleʼs Republic of China (2016YFC1402106). Support for D.M.A. provided by the Woods Hole Oceanographic Institution—Ocean University of China Cooperative Research Initiative. We thank Dr. Juntian Xu, Jing Ma, Ying Li, and Chenglong Ji for assisting culture experiments and sample analysis.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Jiao, F., Cannon, K. S., Lin, Y. C., Gladfelter, A. S., & Scheuring, S. The hierarchical assembly of septins revealed by high-speed AFM. Nature Communications, 11(1), (2020): 5062, doi:10.1038/s41467-020-18778-x.

Description: Septins are GTP-binding proteins involved in diverse cellular processes including division and membrane remodeling. Septins form linear, palindromic heteromeric complexes that can assemble in filaments and higher-order structures. Structural studies revealed various septin architectures, but questions concerning assembly-dynamics and -pathways persist. Here we used high-speed atomic force microscopy (HS-AFM) and kinetic modeling which allowed us to determine that septin filament assembly was a diffusion-driven process, while formation of higher-order structures was complex and involved self-templating. Slightly acidic pH and increased monovalent ion concentrations favor filament-assembly, -alignment and -pairing. Filament-alignment and -pairing further favored diffusion-driven assembly. Pairing is mediated by the septin N-termini face, and may occur symmetrically or staggered, likely important for the formation of higher-order structures of different shapes. Multilayered structures are templated by the morphology of the underlying layers. The septin C-termini face, namely the C-terminal extension of Cdc12, may be involved in membrane binding.

Description: We thank J. Thorner for the generous gift of the CTE mutant plasmids. K.S.C. was supported in part by a grant from NIGMS under award T32 GM119999 and A.S.G., F.J. and S.S. were supported by NIH RO1 GM130934.

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Winkler, T. S., van Hengstum, P. J., Donnelly, J. P., Wallace, E. J., Sullivan, R. M., MacDonald, D., & Albury, N. A. Revising evidence of hurricane strikes on Abaco Island (the Bahamas) over the last 700 years. Scientific Reports, 10(1), (2020): 16556, doi:10.1038/s41598-020-73132-x.

Description: The northern Bahamas have experienced more frequent intense-hurricane impacts than almost anywhere else in the Atlantic since 1850 CE. In 2019, category 5 (Saffir-Simpson scale) Hurricane Dorian demonstrated the destructive potential of these natural hazards. Problematically, determining whether high hurricane activity levels remained constant through time is difficult given the short observational record (〈 170 years). We present a 700-year long, near-annually resolved stratigraphic record of hurricane passage near Thatchpoint Blue Hole (TPBH) on Abaco Island, The Bahamas. Using longer sediment cores (888 cm) and more reliable age-control, this study revises and temporally expands a previous study from TPBH that underestimated the sedimentation rate. TPBH records at least 13 ≥ category 2 hurricanes per century between 1500 to 1670 CE, which exceeds the 9 ≥ category 2 hurricanes per century within 50 km of TPBH since 1850 CE. The eastern United States also experienced frequent hurricanes from 1500 to 1670 CE, but frequency was depressed elsewhere in the Atlantic Ocean. This suggests that spatial heterogeneity in Atlantic hurricane activity since 1850 CE could have persisted throughout the last millennium. This heterogeneity is impacted by climatic and stochastic forcing, but additional high-resolution paleo-hurricane reconstructions are required to assess the mechanisms that impact regional variability.

Description: Field support was provided by Jody Albury and the staff of Friends of the Environment in Marsh Harbour, The Bahamas, and technical support was provided was provided by M. Horgan and S. Molodtsov. Funding for this project was provided by NSF Awards OCE-1356509, OCE-1356708, OCE-1854917, OCE-1903616, and ICER-1854980. The open access publishing fees for this article have been covered by the Texas A&M University Open Access to Knowledge Fund (OAKFund), supported by the University Libraries.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(4), (2020): 887-905, doi:10.1175/JPO-D-19-0110.1.

Description: The Equatorial Undercurrent (EUC) encounters the Galápagos Archipelago on the equator as it flows eastward across the Pacific. The impact of the Galápagos Archipelago on the EUC in the eastern equatorial Pacific remains largely unknown. In this study, the path of the EUC as it reaches the Galápagos Archipelago is measured directly using high-resolution observations obtained by autonomous underwater gliders. Gliders were deployed along three lines that define a closed region with the Galápagos Archipelago as the eastern boundary and 93°W from 2°S to 2°N as the western boundary. Twelve transects were simultaneously occupied along the three lines during 52 days in April–May 2016. Analysis of individual glider transects and average sections along each line show that the EUC splits around the Galápagos Archipelago. Velocity normal to the transects is used to estimate net horizontal volume transport into the volume. Downward integration of the net horizontal transport profile provides an estimate of the time- and areal-averaged vertical velocity profile over the 52-day time period. Local maxima in vertical velocity occur at depths of 25 and 280 m with magnitudes of (1.7 ± 0.6) × 10−5 m s−1 and (8.0 ± 1.6) × 10−5 m s−1, respectively. Volume transport as a function of salinity indicates that water crossing 93°W south (north) of 0.4°S tends to flow around the south (north) side of the Galápagos Archipelago. Comparisons are made between previous observational and modeling studies with differences attributed to effects of the strong 2015/16 El Niño event, the annual cycle of local winds, and varying longitudes between studies of the equatorial Pacific.

Description: This work was supported by National Science Foundation (Grants OCE-1232971 and OCE-1233282) and the NASA Earth and Space Science Fellowship Program (Grant 80NSSC17K0443).

Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Mayfield, K. K., Eisenhauer, A., Santiago Ramos, D. P., Higgins, J. A., Horner, T. J., Auro, M., Magna, T., Moosdorf, N., Charette, M. A., Gonneea, M. E., Brady, C. E., Komar, N., Peucker-Ehrenbrink, B., & Paytan, A. Groundwater discharge impacts marine isotope budgets of Li, Mg, Ca, Sr, and Ba. Nature Communications, 12(1), (2021): 148-020-20248-3, doi:10.1038/s41467-020-20248-3.

Description: Groundwater-derived solute fluxes to the ocean have long been assumed static and subordinate to riverine fluxes, if not neglected entirely, in marine isotope budgets. Here we present concentration and isotope data for Li, Mg, Ca, Sr, and Ba in coastal groundwaters to constrain the importance of groundwater discharge in mediating the magnitude and isotopic composition of terrestrially derived solute fluxes to the ocean. Data were extrapolated globally using three independent volumetric estimates of groundwater discharge to coastal waters, from which we estimate that groundwater-derived solute fluxes represent, at a minimum, 5% of riverine fluxes for Li, Mg, Ca, Sr, and Ba. The isotopic compositions of the groundwater-derived Mg, Ca, and Sr fluxes are distinct from global riverine averages, while Li and Ba fluxes are isotopically indistinguishable from rivers. These differences reflect a strong dependence on coastal lithology that should be considered a priority for parameterization in Earth-system models.

Description: We thank A. Beck, H. Dulai, I. Santos, C. Benitez-Nelson, W. Moore, A. Martin, and H. Windom for sample access. We also thank A. Kolevica, A. Heuser, H. Pryer, J. Middleton, R. Franks, F. Lon, N. Slater, and O. Šebek for their laboratory and analytical assistance. This material is based upon research supported by the National Science Foundation Graduate Research Fellowship Program and an internship provided through the U.S. Geological Survey Graduate Research Internship Program (GRIP). This research was also supported by grants from: the German Academic Exchange Service (DAAD), Northern California chapter of the Achievement Rewards for College Scientists Foundation, International Association of GeoChemistry, Geological Society of America, Northern California Geological Society, Myers Trust, Friends of Long Marine Lab, and UC MEXUS (to K.K.M.). We acknowledge funding from EU-ITN Horizon project 643084 (to A.E. and T.M.) and NSF grant Award Number 1259440 (to A.P.). We also acknowledge funding from NSF grant award number OCE-1736949 (to T.J.H.). Any use of trade, firm or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(10), (2020): 2849-2871, https://doi.org/10.1175/JPO-D-20-0086.1.

Description: The structure, transport, and seasonal variability of the West Greenland boundary current system near Cape Farewell are investigated using a high-resolution mooring array deployed from 2014 to 2018. The boundary current system is comprised of three components: the West Greenland Coastal Current, which advects cold and fresh Upper Polar Water (UPW); the West Greenland Current, which transports warm and salty Irminger Water (IW) along the upper slope and UPW at the surface; and the Deep Western Boundary Current, which advects dense overflow waters. Labrador Sea Water (LSW) is prevalent at the seaward side of the array within an offshore recirculation gyre and at the base of the West Greenland Current. The 4-yr mean transport of the full boundary current system is 31.1 ± 7.4 Sv (1 Sv ≡ 106 m3 s−1), with no clear seasonal signal. However, the individual water mass components exhibit seasonal cycles in hydrographic properties and transport. LSW penetrates the boundary current locally, through entrainment/mixing from the adjacent recirculation gyre, and also enters the current upstream in the Irminger Sea. IW is modified through air–sea interaction during winter along the length of its trajectory around the Irminger Sea, which converts some of the water to LSW. This, together with the seasonal increase in LSW entering the current, results in an anticorrelation in transport between these two water masses. The seasonality in UPW transport can be explained by remote wind forcing and subsequent adjustment via coastal trapped waves. Our results provide the first quantitatively robust observational description of the boundary current in the eastern Labrador Sea.

Description: A.P., R.S.P., F.B., D.J.T., and A.L.R. were funded by Grants OCE-1259618 and OCE-1756361 from the National Science Foundation. I.L.B, F.S., and J.H. were supported by U.S. National Science Foundation Grants OCE-1258823 and OCE-1756272. Mooring data from MA2 was funded by the European Union 7th Framework Programme (FP7 2007-2013) under Grant 308299 (NACLIM) and the Horizon 2020 research and innovation program under Grant 727852 (Blue-Action). J.K. and M.O. acknowledge EU Horizon 2020 funding Grants 727852 (Blue-action) and 862626 (EuroSea) and from the German Ministry of Research and Education (RACE Program). G.W.K.M. acknowledges funding from the Natural Sciences and Engineering Research Council.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 101(11), (2020): E1996-E2004, https://doi.org/10.1175/BAMS-D-19-0305.1.

Description: A long-standing challenge in oceanography is the observing, modeling, and prediction of vertical transport, which links the sunlit and atmospherically mediated surface boundary layer with the deeper ocean. Vertical motions play a critical role in the exchange of heat, freshwater, and biogeochemical tracers between the surface and the ocean interior. The most intense vertical velocities occur at horizontal scales less than 10 km, making them difficult to observe in the ocean and to resolve in models. Understanding how finescale turbulent motions and 0.1–10 km submesoscale processes contribute to the large-scale budgets of nutrients, oxygen, carbon, and heat and affect sea surface temperature, the air–sea exchange of gases, and the carbon cycle is one of the key challenges in oceanography.

Description: CALYPSO is a Departmental Research Initiative (DRI) funded by the U.S. Office of Naval Research (ONR). It is a collaborative program involving more than 30 scientists and students and multiple institutions in the United States, Spain, and Italy. Measurements were conducted from the NRV Alliance, Pourquoi Pas?, and SOCIB. We are grateful to the captains and crews of these research vessels and the technical and scientific staff involved in making measurements, running models, analyzing data, and providing support.

Description: 2021-05-01

Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Skottene, E., Tarrant, A. M., Altin, D., Olsen, R. E., Choquet, M., & Kvile, K. O. Lipid metabolism in Calanus finmarchicus is sensitive to variations in predation risk and food availability. Scientific Reports, 10(1),(2020): 22322, https://doi.org/10.1038/s41598-020-79165-6.

Description: Late developmental stages of the marine copepods in the genus Calanus can spend extended periods in a dormant stage (diapause) that is preceded by the accumulation of large lipid stores. We assessed how lipid metabolism during development from the C4 stage to adult is altered in response to predation risk and varying food availability, to ultimately understand more of the metabolic processes during development in Calanus copepods. We used RNA sequencing to assess if perceived predation risk in combination with varied food availability affects expression of genes associated with lipid metabolism and diapause preparation in C. finmarchicus. The lipid metabolism response to predation risk differed depending on food availability, time and life stage. Predation risk caused upregulation of lipid catabolism with high food, and downregulation with low food. Under low food conditions, predation risk disrupted lipid accumulation. The copepods showed no clear signs of diapause preparation, supporting earlier observations of the importance of multiple environmental cues in inducing diapause in C. finmarchicus. This study demonstrates that lipid metabolism is a sensitive endpoint for the interacting environmental effects of predation pressure and food availability. As diapause may be controlled by lipid accumulation, our findings may contribute towards understanding processes that can ultimately influence diapause timing.

Description: ES was funded by the Department of Biology, Norwegian University of Science and Technology. Support for AMT was provided by the National Science Foundation (NSF) OPP-1746087. KØK was funded by VISTA—a basic research program in collaboration between The Norwegian Academy of Science and Letters, and Equinor. The RNA seq work was provided by the Genomics Core Facility (GCF). GCF is funded by the Faculty of Medicine and Health Sciences at NTNU and Central Norway Regional Health Authority. The authors thank Lotte Thommesen for help conducting the experiment, Mari-Ann Østensen for performing RNA extraction with ES and preparing cDNA libraries for Illumina RNAseq, and the EMBRC-ERIC Laboratory for Low Level Trophic Interactions at NTNU SeaLab for access to the Calanus finmarchicus culture.

Description: Author Posting. © American Meteorological Society, 2020. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 50(4), (2020): 1045-1064, doi:10.1175/JPO-D-19-0137.1.

Description: Three simulations of the circulation in the Gulf of Mexico (the “Gulf”) using different numerical general circulation models are compared with results of recent large-scale observational campaigns conducted throughout the deep (〉1500 m) Gulf. Analyses of these observations have provided new understanding of large-scale mean circulation features and variability throughout the deep Gulf. Important features include cyclonic flow along the continental slope, deep cyclonic circulation in the western Gulf, a counterrotating pair of cells under the Loop Current region, and a cyclonic cell to the south of this pair. These dominant circulation features are represented in each of the ocean model simulations, although with some obvious differences. A striking difference between all the models and the observations is that the simulated deep eddy kinetic energy under the Loop Current region is generally less than one-half of that computed from observations. A multidecadal integration of one of these numerical simulations is used to evaluate the uncertainty of estimates of velocity statistics in the deep Gulf computed from limited-length (4 years) observational or model records. This analysis shows that the main deep circulation features identified from the observational studies appear to be robust and are not substantially impacted by variability on time scales longer than the observational records. Differences in strengths and structures of the circulation features are identified, however, and quantified through standard error analysis of the statistical estimates using the model solutions.

Description: This work was supported by the Gulf Research Program of the National Academy of Sciences under Awards 2000006422 and 2000009966. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Gulf Research Program or the National Academy of Sciences. The authors acknowledge the GLORYS project for providing the ocean reanalysis data used in the ROMS simulation. GLORYS is jointly conducted by MERCATOR OCEAN, CORIOLIS, and CNRS/INSU. Installation, recovery, data acquisition, and processing of the CANEK group current-meter moorings were possible because of CICESE-PetróleosMexicanos Grant PEP-CICESE 428229851 and the dedicated work of the crew of the B/O Justo Sierra and scientists of the CANEK group. The authors thank Dr. Aljaz Maslo, CICESE, for assistance with analysis of model data. The Bureau of Ocean Energy Management (BOEM), U.S. Dept. of the Interior, provided funding for the Lagrangian Study of the Deep Circulation in the Gulf of Mexico and the Observations and Dynamics of the Loop Current study. HYCOM simulation data are available from the HYCOM data server (https://www.hycom.org/data/goml0pt04/expt-02pt2), MITgcm data are available from the ECCO data server (http://ecco.ucsd.edu/gom_results2.html), and the ROMS simulation data are available from GRIIDC (NA.x837.000:0001).

Description: © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Marshall, T., Granger, J., Casciotti, K. L., Dahnke, K., Emeis, K.-C., Marconi, D., McIlvin, M. R., Noble, A. E., Saito, M. A., Sigman, D. M., & Fawcett, S. E. The Angola Gyre is a hotspot of dinitrogen fixation in the South Atlantic Ocean. Communications Earth & Environment, 3(1), (2022): 151, https://doi.org/10.1038/s43247-022-00474-x.

Description: Biological dinitrogen fixation is the major source of new nitrogen to marine systems and thus essential to the ocean’s biological pump. Constraining the distribution and global rate of dinitrogen fixation has proven challenging owing largely to uncertainty surrounding the controls thereon. Existing South Atlantic dinitrogen fixation rate estimates vary five-fold, with models attributing most dinitrogen fixation to the western basin. From hydrographic properties and nitrate isotope ratios, we show that the Angola Gyre in the eastern tropical South Atlantic supports the fixation of 1.4–5.4 Tg N.a−1, 28-108% of the existing (highly uncertain) estimates for the basin. Our observations contradict model diagnoses, revealing a substantial input of newly-fixed nitrogen to the tropical eastern basin and no dinitrogen fixation west of 7.5˚W. We propose that dinitrogen fixation in the South Atlantic occurs in hotspots controlled by the overlapping biogeography of excess phosphorus relative to nitrogen and bioavailable iron from margin sediments. Similar conditions may promote dinitrogen fixation in analogous ocean regions. Our analysis suggests that local iron availability causes the phosphorus-driven coupling of oceanic dinitrogen fixation to nitrogen loss to vary on a regional basis.

Description: This work was supported by the South African National Research Foundation (114673 and 130826 to T.M., 115335, 116142 and 129320 to S.E.F.); the US National Science Foundation (CAREER award, OCE-1554474 to J.G., OCE-1736652 to D.M.S. and K.L.C., OCE-05-26277 to K.L.C.); the German Federal Agency for Education and Research (DAAD-SPACES 57371082 to T.M.); the Royal Society (FLAIR fellowship to S.E.F.); and the University of Cape Town (T.M., J.G., S.E.F.). The authors also recognize the support of the South African Department of Science and Innovation’s Biogeochemistry Research Infrastructure Platform (BIOGRIP).

Description: Author Posting. © American Meteorological Society, 2022. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 52(10), (2022): 2431-2444, https://doi.org/10.1175/jpo-d-22-0024.1.

Description: A three-dimensional inertial model that conserves quasigeostrophic potential vorticity is proposed for wind-driven coastal upwelling along western boundaries. The dominant response to upwelling favorable winds is a surface-intensified baroclinic meridional boundary current with a subsurface countercurrent. The width of the current is not the baroclinic deformation radius but instead scales with the inertial boundary layer thickness while the depth scales as the ratio of the inertial boundary layer thickness to the baroclinic deformation radius. Thus, the boundary current scales depend on the stratification, wind stress, Coriolis parameter, and its meridional variation. In contrast to two-dimensional wind-driven coastal upwelling, the source waters that feed the Ekman upwelling are provided over the depth scale of this baroclinic current through a combination of onshore barotropic flow and from alongshore in the narrow boundary current. Topography forces an additional current whose characteristics depend on the topographic slope and width. For topography wider than the inertial boundary layer thickness the current is bottom intensified, while for narrow topography the current is wave-like in the vertical and trapped over the topography within the inertial boundary layer. An idealized primitive equation numerical model produces a similar baroclinic boundary current whose vertical length scale agrees with the theoretical scaling for both upwelling and downwelling favorable winds.

Description: This research is supported in part by the China Scholarship Council (201906330102). H. G. is financially supported by the China Scholarship Council to study at WHOI for 2 years as a guest student. M.S. is supported by the National Science Foundation Grant OCE-1922538. Z. C. is supported by the ‘Taishan/Aoshan’ Talents program (2017ASTCPES05) the Fundamental Research Funds for the Central Universities (202072001).

Description: 2023-03-30