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  • 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation  (30)
  • 04. Solid Earth::04.01. Earth Interior::04.01.02. Geological and geophysical evidences of deep processes
  • Biological pump
  • historical earthquakes
  • INGV  (36)
  • Elsevier Science Limited  (18)
  • John Wiley & Sons  (6)
  • American Association for the Advancement of Science  (2)
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Keywords
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  • 1
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    An in-depth analysis on the Quasi-Longitudinal approximations applied to ionospheric ray-tracing, oblique and vertical sounding, and absorption (2022)
    INGV
    Details
    Publication Date: 2022-06-22
    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
    Keywords: Appleton-Hartree’s formula ; Booker’s rule ; ″Strong″ and ″weak″ Quasi-Longitudinal (QL) conditions ; Walker’s approximation ; Ionospheric HF ray-tracing, oblique and vertical sounding, and absorption ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 01. Atmosphere::01.02. Ionosphere::01.02.04. Plasma Physics ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 05. General::05.01. Computational geophysics::05.01.99. General or miscellaneous ; 05. General::05.01. Computational geophysics::05.01.05. Algorithms and implementation
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
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  • 2
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    Global assessment of ocean carbon export by combining satellite observations and food-web models (2014)
    John Wiley & Sons
    Details
    Publication Date: 2022-05-26
    Description: Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 28 (2014): 181-196, doi:10.1002/2013GB004743.
    Description: The export of organic carbon from the surface ocean by sinking particles is an important, yet highly uncertain, component of the global carbon cycle. Here we introduce a mechanistic assessment of the global ocean carbon export using satellite observations, including determinations of net primary production and the slope of the particle size spectrum, to drive a food-web model that estimates the production of sinking zooplankton feces and algal aggregates comprising the sinking particle flux at the base of the euphotic zone. The synthesis of observations and models reveals fundamentally different and ecologically consistent regional-scale patterns in export and export efficiency not found in previous global carbon export assessments. The model reproduces regional-scale particle export field observations and predicts a climatological mean global carbon export from the euphotic zone of ~6 Pg C yr−1. Global export estimates show small variation (typically 〈 10%) to factor of 2 changes in model parameter values. The model is also robust to the choices of the satellite data products used and enables interannual changes to be quantified. The present synthesis of observations and models provides a path for quantifying the ocean's biological pump.
    Description: D.A.S. and K.O.B. acknowledge support from the National Aeronautics and Space Administration (NNX11AF63G). S.C.D. and S.F.S. acknowledge support from the National Science Foundation through the Center for Microbial Oceanography: Research and Education (C-MORE) (NSF EF-0424599).
    Description: 2014-09-10
    Keywords: Carbon cycle ; Biological pump ; Carbon export ; Remote sensing ; Food webs
    Repository Name: Woods Hole Open Access Server
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  • 3
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    The annual cycle of gross primary production, net community production, and export efficiency across the North Pacific Ocean (2016)
    John Wiley & Sons
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 30 (2016): 361–380, doi:10.1002/2015GB005318.
    Description: We measured triple oxygen isotopes and oxygen/argon dissolved gas ratios as nonincubation-based geochemical tracers of gross oxygen production (GOP) and net community production (NCP) on 16 container ship transects across the North Pacific from 2008 to 2012. We estimate rates and efficiency of biological carbon export throughout the full annual cycle across the North Pacific basin (35°N–50°N, 142°E–125°W) by constructing mixed layer budgets that account for physical and biological influences on these tracers. During the productive season from spring to fall, GOP and NCP are highest in the Kuroshio region west of 170°E and decrease eastward across the basin. However, deep winter mixed layers (〉200 m) west of 160°W ventilate ~40–90% of this seasonally exported carbon, while only ~10% of seasonally exported carbon east of 160°W is ventilated in winter where mixed layers are 〈120 m. As a result, despite higher annual GOP in the west than the east, the annual carbon export (sequestration) rate and efficiency decrease westward across the basin from export of 2.3 ± 0.3 mol C m−2 yr−1 east of 160°W to 0.5 ± 0.7 mol C m−2 yr−1 west of 170°E. Existing productivity rate estimates from time series stations are consistent with our regional productivity rate estimates in the eastern but not western North Pacific. These results highlight the need to estimate productivity rates over broad spatial areas and throughout the full annual cycle including during winter ventilation in order to accurately estimate the rate and efficiency of carbon sequestration via the ocean's biological pump.
    Description: This work was funded by a NDSEG Fellowship from the Office of Naval Research, a NSF Graduate Research Fellowship, and an ARCS Foundation Fellowship to H.I.P. and by NSF Ocean Sciences (0628663 and 1259055 to P.D.Q.).
    Description: 2016-08-27
    Keywords: North Pacific ; Carbon cycle ; Productivity ; Biological pump ; Gross oxygen production ; Net community production
    Repository Name: Woods Hole Open Access Server
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  • 4
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    An inverse relationship between production and export efficiency in the Southern Ocean (2013)
    John Wiley & Sons
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 1557–1561, doi:10.1002/grl.50219.
    Description: In the past two decades, a number of studies have been carried out in the Southern Ocean to look at export production using drifting sediment traps and thorium-234 based measurements, which allows us to reexamine the validity of using the existing relationships between production, export efficiency, and temperature to derive satellite-based carbon export estimates in this region. Comparisons of in situ export rates with modeled rates indicate a two to fourfold overestimation of export production by existing models. Comprehensive analysis of in situ data indicates two major reasons for this difference: (i) in situ data indicate a trend of decreasing export efficiency with increasing production which is contrary to existing export models and (ii) the export efficiencies appear to be less sensitive to temperature in this region compared to the global estimates used in the existing models. The most important implication of these observations is that the simplest models of export, which predict increase in carbon flux with increasing surface productivity, may require additional parameters, different weighing of existing parameters, or separate algorithms for different oceanic regimes.
    Description: This work was supported by NASA award number NNX08AB48G.
    Description: 2013-10-23
    Keywords: Biological pump ; Southern Ocean ; Carbon export
    Repository Name: Woods Hole Open Access Server
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  • 5
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    Discrepant estimates of primary and export production from satellite algorithms, a biogeochemical model, and geochemical tracer measurements in the North Pacific Ocean (2016)
    John Wiley & Sons
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2016. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 43 (2016): 8645–8653, doi:10.1002/2016GL070226.
    Description: Estimates of primary and export production (PP and EP) based on satellite remote sensing algorithms and global biogeochemical models are widely used to provide year-round global coverage not available from direct observations. However, observational data to validate these approaches are limited. We find that no single satellite algorithm or model can reproduce seasonal and annual geochemically determined PP, export efficiency (EP/PP), and EP rates throughout the North Pacific basin, based on comparisons throughout the full annual cycle at time series stations in the subarctic and subtropical gyres and basin-wide regions sampled by container ship transects. The high-latitude regions show large PP discrepancies in winter and spring and strong effects of deep winter mixed layers on annual EP that cannot be accounted for in current satellite-based approaches. These results underscore the need to evaluate satellite- and model-based estimates using multiple productivity parameters measured over broad ocean regions throughout the annual cycle.
    Description: NDSEG Fellowship from the Office of Naval Research; NSF Graduate Research Fellowship; ARCS Foundation Fellowship
    Description: 2017-02-28
    Keywords: North Pacific ; Productivity ; Biological pump ; Carbon cycle
    Repository Name: Woods Hole Open Access Server
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  • 6
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    Influence of biological carbon export on ocean carbon uptake over the annual cycle across the North Pacific Ocean (2017)
    John Wiley & Sons
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 31 (2017): 81–95, doi:10.1002/2016GB005527.
    Description: We evaluate the influences of biological carbon export, physical circulation, and temperature-driven solubility changes on air-sea CO2 flux across the North Pacific basin (35°N–50°N, 142°E–125°W) throughout the full annual cycle by constructing mixed layer budgets for dissolved inorganic carbon (DIC) and pCO2, determined on 15 container ship transects between Hong Kong and Long Beach, CA, from 2008 to 2012. Annual air-sea CO2 flux is greatest in the western North Pacific and decreases eastward across the basin (2.7 ± 0.9 mol C m−2 yr−1 west of 170°E, as compared to 2.1 ± 0.3 mol C m−2 yr−1 east of 160°W). East of 160°W, DIC removal by annual net community production (NCP) more than fully offsets the DIC increase due to air-sea CO2 flux. However, in the region west of 170°E influenced by deep winter mixing, annual NCP only offsets ~20% of the DIC increase due to air-sea CO2 flux, requiring significant DIC removal by geostrophic advection. Temperature-driven solubility changes have no net influence on pCO2 and account for 〈25% of annual CO2 uptake. The seasonal timing of NCP strongly affects its influence on air-sea CO2 flux. Biological carbon export from the mixed layer has a stronger influence on pCO2 in summer when mixed layers are shallow, but changes in pCO2 have a stronger influence on air-sea CO2 flux in winter when high wind speeds drive more vigorous gas exchange. Thus, it is necessary to determine the seasonal timing as well as the annual magnitude of NCP to determine its influence on ocean carbon uptake.
    Description: NDSEG Fellowship from the Office of Naval Research; NSF Graduate Research Fellowship; NSF Ocean Sciences Grant Numbers: 0628663, 1259055; NOAA Climate Program Office Grant Number: A10OAR4310088
    Description: 2017-07-21
    Keywords: Carbon cycle ; North Pacific ; Biological pump
    Repository Name: Woods Hole Open Access Server
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  • 7
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    Effects of sinking velocities and microbial respiration rates on the attenuation of particulate carbon fluxes through the mesopelagic zone (2015)
    John Wiley & Sons
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 2015. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 29 (2015): 175–193, doi:10.1002/2014GB004935.
    Description: The attenuation of sinking particle fluxes through the mesopelagic zone is an important process that controls the sequestration of carbon and the distribution of other elements throughout the oceans. Case studies at two contrasting sites, the oligotrophic regime of the Bermuda Atlantic Time-series Study (BATS) and the mesotrophic waters of the west Antarctic Peninsula (WAP) sector of the Southern Ocean, revealed large differences in the rates of particle-attached microbial respiration and the average sinking velocities of marine particles, two parameters that affect the transfer efficiency of particulate matter from the base of the euphotic zone into the deep ocean. Rapid average sinking velocities of 270 ± 150 m d−1 were observed along the WAP, whereas the average velocity was 49 ± 25 m d−1 at the BATS site. Respiration rates of particle-attached microbes were measured using novel RESPIRE (REspiration of Sinking Particles In the subsuRface ocEan) sediment traps that first intercepts sinking particles then incubates them in situ. RESPIRE experiments yielded flux-normalized respiration rates of 0.4 ± 0.1 day−1 at BATS when excluding an outlier of 1.52 day−1, while these rates were undetectable along the WAP (0.01 ± 0.02 day−1). At BATS, flux-normalized respiration rates decreased exponentially with respect to depth below the euphotic zone with a 75% reduction between the 150 and 500 m depths. These findings provide quantitative and mechanistic insights into the processes that control the transfer efficiency of particle flux through the mesopelagic and its variability throughout the global oceans.
    Description: Funding was provided by the University of Alaska Fairbanks, Woods Hole Oceanographic Institution (WHOI) Rinehart Access to the Sea Program, the WHOI Coastal Oceans Institute, WHOI Academic Programs Office, and the National Science Foundation (NSF) for support of PAL (ANT-0823101), FOODBANCS, and WAPflux (ANT- 83886600) projects. A grant from the NSF Carbon and Water Program (06028416) supported the development of these methods.
    Description: 2015-08-25
    Keywords: Biological pump ; Marine particles ; Carbon flux ; Sinking velocity ; Microbial respiration
    Repository Name: Woods Hole Open Access Server
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  • 8
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    A spectral study of the mid-latitude sporadic E layer characteristic oscillations comparable to those of the tidal and the planetary waves (2015)
    Elsevier Science Limited
    Details
    Publication Date: 2022-02-02
    Description: In this paper different spectral analyses are employed to investigate the tidal and planetary wave peri-odicities imprinted in the following two main characteristics of the sporadicE(Es)layer: the top fre-quency (ftEs) and the lowest virtual height(h′Es). The study is based on ionograms recorded during the summertime of 2013, and precisely in June, July, August and September, by the Advanced Ionospheric Sounder by Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed at Rome (41.8°N, 12.5°E) and Gibilmanna (37.9°N, 14.0°E), Italy. It was confirmed that the diurnal and semidiurnal atmospheric tides play a fundamental role in the formation of the mid-latitude Eslayers, acting through their vertical wind-shear forcing of the long-living metallic ions in the lower thermosphere, and at the same time it was found that the planetary atmospheric waves might affect the Es layers acting through their horizontal wind-shear forcing with periods close to the normal Rossby modes, that is 2, 5, 10 and 16 days. The wavelet analysis shows also that the ftEs and h′Es tidal oscillations undergo a strong amplitude modulation with periods of several days and with important differences between the two parameters. This amplitude modulation, characterizing markedly the first thirty days of the ftEs spectrogram, suggests that Es layers areaffected indirectly by planetary waves through their nonlinear interaction with the atmospheric tides at lower altitudes. This study wants to be a continuation of the Haldoupis et al.(2004) work in order to verify their results for the foEs characteristic and on the other hand to extend the study also to the h′Es characteristic not yet shown so far. Anyhow, the study confirms that ionosonde data, especially those registered in summertime, represent a powerful tool for studying tidal and planetary waves properties and their climatology in the mesosphere–low-thermosphere region.
    Description: Published
    Description: 34-44
    Description: 2A. Fisica dell'alta atmosfera
    Description: JCR Journal
    Description: restricted
    Keywords: Sporadic Elayer ; Tidal waves ; Planetary waves ; Waveletanalysis ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 01. Atmosphere::01.02. Ionosphere::01.02.02. Dynamics ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 9
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    On the solar cycle dependence of the amplitude modulation characterizing the mid-latitude sporadic E layer diurnal periodicity (2015)
    Elsevier Science Limited
    Details
    Publication Date: 2022-02-02
    Description: Spectral analyses are employed to investigate how the diurnal periodicity of the critical frequency of the sporadic E (Es) layer varies with solar activity. The study is based on ionograms recorded at the ionospheric station of Rome (41.8°N, 12.5°E), Italy, from 1976 to 2009, a period of time covering three solar cycles. It was confirmed that the diurnal periodicity is always affected by an amplitude modulation with periods of several days, which is the proof that Es layers are affected indirectly by planetary waves through their non linear interaction with atmospheric tides at lower altitudes. The most striking features coming out from this study is however that this amplitude modulation is greater for high-solar activity than for low-solar activity.
    Description: Published
    Description: 29-35
    Description: 2A. Fisica dell'alta atmosfera
    Description: 1IT. Reti di monitoraggio e Osservazioni
    Description: 4IT. Banche dati
    Description: JCR Journal
    Description: open
    Keywords: Sporadic E layer ; Mid-latitude ionosphere ; Tidal and Planetary wave ; Nonlinear interaction ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 01. Atmosphere::01.02. Ionosphere::01.02.02. Dynamics ; 01. Atmosphere::01.02. Ionosphere::01.02.04. Plasma Physics ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques ; 05. General::05.07. Space and Planetary sciences::05.07.01. Solar-terrestrial interaction ; 05. General::05.07. Space and Planetary sciences::05.07.02. Space weather
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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  • 10
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    20 March 2015 solar eclipse influence on sporadic E layer (2015)
    Elsevier Science Limited
    Details
    Publication Date: 2021-06-07
    Description: This paper shows how the solar eclipse occurred on 20 March 2015 influenced the sporadic E (Es) layer as recorded by the Advanced Ionospheric Sounder by Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed at Rome (41.8°N, 12.5°E) and Gibilmanna (37.9°N, 14.0°E), Italy. In these locations, the solar eclipse was only partial, with the maximum area of the solar disk obscured by the Moon equal to ~54% at Rome and ~45% at Gibilmanna. Nevertheless, it is shown that the strong thermal gradients that usually accompany a solar eclipse, have significantly influenced the Es phenomenology. Specifically, the solar eclipse did not affect the Es layer in terms of its maximum intensity, which is comparable with that of the previous and next day, but rather in terms of its persistence. In fact, both at Rome and Gibilmanna, contrary to what typically happens in March, the Es layer around the solar eclipse time is always present. On the other hand, this persistence is also confirmed by the application of the height–time–intensity (HTI) technique. A detailed analysis of isoheight ionogram plots suggests that traveling ionospheric disturbances (TIDs) likely caused by gravity wave (GW) propagation have played a significant role in causing the persistence of the Es layer.
    Description: Published
    Description: 2064–2072
    Description: 1A. Geomagnetismo e Paleomagnetismo
    Description: 2A. Fisica dell'alta atmosfera
    Description: 1IT. Reti di monitoraggio e Osservazioni
    Description: JCR Journal
    Description: restricted
    Keywords: Mid-latitude ionosphere ; E sporadic layer ; Solar eclipse ; Gravity wave ; Height–time–intensity technique ; 01. Atmosphere::01.02. Ionosphere::01.02.99. General or miscellaneous ; 01. Atmosphere::01.02. Ionosphere::01.02.04. Plasma Physics ; 01. Atmosphere::01.02. Ionosphere::01.02.05. Wave propagation ; 01. Atmosphere::01.02. Ionosphere::01.02.06. Instruments and techniques ; 05. General::05.07. Space and Planetary sciences::05.07.01. Solar-terrestrial interaction
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
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