ALBERT

Description: MicroHH 1.0: a computational fluid dynamics code for direct numerical simulation and large-eddy simulation of atmospheric boundary layer flows Chiel C. van Heerwaarden, Bart J. H. van Stratum, Thijs Heus, Jeremy A. Gibbs, Evgeni Fedorovich, and Juan-Pedro Mellado Geosci. Model Dev. Discuss., doi:10.5194/gmd-2017-41,2017 Manuscript under review for GMD (discussion: open, 0 comments) MicroHH ( ww.microhh.org ) is a new and open source computational fluid dynamics code for the simulation of turbulent flows in the atmosphere. It is made the simulate atmospheric flows up to the finest detail levels at very high resolution. It has been designed from scratch in order to use a modern design that allows the code to run on more than 10.000 cores, as well as on a Graphical Processing Unit.

Description: Historical (1750–2014) anthropogenic emissions of reactive gases and aerosols from the Community Emission Data System (CEDS) Rachel M. Hoesly, Steven J. Smith, Leyang Feng, Zbigniew Klimont, Greet Janssens-Maenhout, Tyler Pitkanen, Jonathan J. Seibert, Linh Vu, Robert J. Andres, Ryan M. Bolt, Tami C. Bond, Laura Dawidowski, Nazar Kholod, Jun-ichi Kurokawa, Meng Li, Liang Liu, Zifeng Lu, Maria Cecilia P. Moura, Patrick R. O'Rourke, and Qiang Zhang Geosci. Model Dev. Discuss., doi:10.5194/gmd-2017-43,2017 Manuscript under review for GMD (discussion: open, 0 comments) Historical emission trends are key inputs to earth systems and atmospheric chemistry models. We present a new data set of historical (1750–2014) anthropogenic gases (CO, CH 4 , NH 3 , NO X , SO 2 , NMVOC, BC, OC, and CO 2 ) developed with the Community Emissions Database System (CEDS). This improves on existing inventories as it uses consistent methods and data across emissions species, has annual resolution for a longer and more recent time series, and is designed to be transparent and reproducible.

Description: Modelling of sediment transport and morphological evolution under the combined action of waves and currents Guilherme Franz, Matthias T. Delpey, David Brito, Lígia Pinto, Paulo Leitão, and Ramiro Neves Ocean Sci. Discuss., doi:10.5194/os-2017-8,2017 Manuscript under review for OS (discussion: open, 0 comments) The paper describes a numerical modelling methodology capable of reproducing the hydrodynamics, sediment transport and morphological evolution of coastal zones under the combined action of waves and currents. The long-term beach response to different designs of coastal defence structures was assessed, as well as the formation of multiple sandbars on the beach slope. The methodology can be applied in engineering studies in order to evaluate the best solution to protect the coast against erosion.

Description: Evaluating the effect of alternative carbon allocation schemes in a land surface model (CLM4.5) on carbon fluxes, pools and turnover in temperate forests Francesc Montané, Andrew M. Fox, Avelino F. Arellano, Natasha MacBean, M. Ross Alexander, Alex Dye, Daniel A. Bishop, Valerie Trouet, Flurin Babst, Amy E. Hessl, Neil Pederson, Peter D. Blanken, Gil Bohrer, Christopher M. Gough, Marcy E. Litvak, Kimberly A. Novick, Richard P. Phillips, Jeffrey D. Wood, and David J. P. Moore Geosci. Model Dev. Discuss., doi:10.5194/gmd-2017-74,2017 Manuscript under review for GMD (discussion: open, 0 comments) How carbon is allocated to different plant tissues (leaves, stem, and roots) determines carbon residence time and thus remains a central challenge for understanding the global carbon cycle. In this paper, we used a state-of-the-art land surface model (CLM4.5) with its standard carbon allocation scheme, and we implemented alternative carbon allocation schemes based on published papers. One of the alternative allocation schemes improved aboveground biomass estimates in most of our sites.

Description: Heterogeneity measures in hydrological frequency analysis: review and new developments Ana I. Requena, Fateh Chebana, and Taha B. M. J. Ouarda Hydrol. Earth Syst. Sci., 21, 1651-1668, doi:10.5194/hess-21-1651-2017, 2017 The notion of a measure to quantify the degree of heterogeneity of a region from which information is required to estimate the magnitude of events at ungauged sites is introduced. These heterogeneity measures are needed to compare regions, evaluate the impact of particular sites, and rank the performance of delineating methods. A framework to define and assess their desirable properties is proposed. Several heterogeneity measures are presented and/or developed to be assessed, giving guidelines.

Description: Long-term projections of global water use for electricity generation under the Shared Socioeconomic Pathways and climate mitigation scenarios Nozomi Ando, Sayaka Yoshikawa, Shinichiro Fujimori, and Shinjiro Kanae Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2017-27,2017 Manuscript under review for HESS (discussion: open, 0 comments) Electricity generation may become a key factor that accelerates water scarcity. In this study, we estimated the future global water use for electricity generation from 2005 to 2100 in 17 global sub-regions. Consequently, We indicated that the socioeconomic changes had a larger impact on water withdrawal and consumption for electricity generation, compared with the climate mitigation changes represented by the climate mitigation scenarios.

Description: Recent changes in terrestrial water storage in the Upper Nile Basin: an evaluation of commonly used gridded GRACE products Mohammad Shamsudduha, Richard G. Taylor, Darren Jones, Laurent Longuevergne, Michael Owor, and Callist Tindimugaya Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2017-146,2017 Manuscript under review for HESS (discussion: open, 0 comments) This study tests the ability of five commonly used GRACE satellite datasets to measure a large and accurately observed reduction in water storage of 75 km 3 that occurred in the Lake Victoria Basin of East Africa from 2004 to 2006. Substantial differences among the datasets to represent the amplitude of this change in the total terrestrial water storage are revealed. Resolving changes in groundwater storage specifically from GRACE data is hindered by uncertainty in simulated soil moisture data.

Description: Identification of dominant hydrogeochemical processes for groundwaters in the Algerian Sahara supported by inverse modeling of chemical and isotopic data Rabia Slimani, Abdelhamid Guendouz, Fabienne Trolard, Adnane Souffi Moulla, Belhadj Hamdi-Aïssa, and Guilhem Bourrié Hydrol. Earth Syst. Sci., 21, 1669-1691, doi:10.5194/hess-21-1669-2017, 2017 Unpublished chemical and isotopic data taken in November 1992 from the three major Saharan aquifers, namely the Continental Intercalaire (CI), the Complexe Terminal (CT) and the phreatic aquifer (Phr), were integrated with original samples in order to chemically and isotopically characterize the largest Saharan aquifer system and investigate the processes through which groundwaters acquire their mineralization. Instead of classical Debye–Hückel extended law, a specific interaction theory (SIT) model, recently incorporated in PHREEQC 3.0, was used. Inverse modeling of hydrochemical data constrained by isotopic data was used here to quantitatively assess the influence of geochemical processes: at depth, the dissolution of salts from the geological formations during upward leakage without evaporation explains the transitions from CI to CT and to a first end member, a cluster of Phr (cluster I); near the surface, the dissolution of salts from sabkhas by rainwater explains another cluster of Phr (cluster II). In every case, secondary precipitation of calcite occurs during dissolution. All Phr waters result from the mixing of these two clusters together with calcite precipitation and ion exchange processes. These processes are quantitatively assessed by the PHREEQC model. Globally, gypsum dissolution and calcite precipitation were found to act as a carbon sink.

Description: Estimation of bubbled-mediated air/sea gas exchange from concurrent DMS and CO 2 transfer velocities at intermediate-high wind speeds Thomas G. Bell, Sebastian Landwehr, Scott D. Miller, Warren J. de Bruyn, Adrian Callaghan, Brian Scanlon, Brian Ward, Mingxi Yang, and Eric S. Saltzman Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-85,2017 Manuscript under review for ACP (discussion: open, 0 comments) The mechanisms that determine the air/sea exchange of gases such as carbon dioxide are not well understood. During a research cruise in the North Atlantic, we simultaneously measured the air/sea transfer of two gases with contrasting solubility over a range in wind and wave conditions. We compare the transfer of these gases to improve understanding of how bubbles from breaking waves may mediate air/sea gas fluxes.

Description: Sources and atmospheric processing of winter aerosols in Seoul, Korea: insights from real-time measurements using a high-resolution aerosol mass spectrometer Hwajin Kim, Qi Zhang, Gwi-Nam Bae, Jin Young Kim, and Seung Bok Lee Atmos. Chem. Phys., 17, 2009-2033, doi:10.5194/acp-17-2009-2017, 2017 We discuss characteristics, sources, and size distributions of the PM 1 composition and OA components in Seoul, Korea, in winter. The serious pollution observed was caused by a combination of various factors, including meteorological conditions, emissions from local primary sources, secondary formation, and transport of air masses from upwind locations. This will be very useful for enacting effective PM reduction strategies for Korea as well as for the broader northern pan-Eurasian region.

Description: Aerosol concentrations determine the height of warm rain and ice initiation in convective clouds over the Amazon basin Ramon Campos Braga, Daniel Rosenfeld, Ralf Weigel, Tina Jurkat, Meinrat O. Andreae, Manfred Wendisch, Ulrich Pöschl, Christiane Voigt, Christoph Mahnke, Stephan Borrmann, Rachel I. Albrecht, Sergej Molleker, Daniel A. Vila, Luiz A. T. Machado, and Lucas Grulich Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1155,2017 Manuscript under review for ACP (discussion: open, 0 comments) We have investigated how pollution aerosols affect the height above cloud base of rain and ice hydrometeor initiation and the subsequent vertical evolution of cloud droplet size and number concentrations in growing convective cumulus. For this purpose we used in-situ data of hydrometeor size distributions measured with instruments mounted on HALO (High Altitude and Long Range Research Aircraft) during the ACRIDICON-CHUVA campaign over the Amazon during September 2014. The results show that the height of rain initiation by collision and coalescence processes ( D r , in units of meters above cloud base) is linearly correlated with the number concentration of droplets ( N d in cm −3 ) nucleated at cloud base ( D r  ≈ 5  N d ). When N d exceeded values of about 1000 cm −3 , D r became greater than 5000 m, and particles of precipitation size were initiated as ice hydrometeors. Therefore, no liquid water raindrops were observed within growing convective cumulus during polluted conditions. Furthermore, also the formation of ice particles took place at higher altitudes in the clouds in polluted conditions, because the resulting smaller cloud droplets froze at colder temperatures compared to the larger drops in the unpolluted cases. The measured vertical profiles of droplet effective radius ( r e ) were close to those estimated by assuming adiabatic conditions ( r ea ), supporting the hypothesis that the entrainment and mixing of air into convective clouds is almost completely inhomogeneous. Secondary nucleation of droplets on aerosol particles from biomass burning and air pollution reduced re below r ea , which further inhibited the formation of raindrops and ice particles and resulted in even higher altitudes for rain and ice initiation.

Description: Quantifying nutrient fluxes with a new hyporheic passive flux meter (HPFM) Julia Vanessa Kunz, Michael D. Annable, Jaehyun Cho, Wolf von Tümpling, Kirk Hatfield, Suresh Rao, Dietrich Borchardt, and Michael Rode Biogeosciences, 14, 631-649, doi:10.5194/bg-14-631-2017, 2017 The hyporheic zone, the subsurface region of streams, is a key compartment for in-stream nutrient retention. Knowledge on actual hyporheic processing rates is still limited due to methodological restrictions which are mainly related to the high local and temporal variability of subsurface flow patterns and nutrient transformation processes. We present a new device which allows quantitative assessment of hyporheic nutrient fluxes and demonstrate its advantages in an exemplary field testing.

Description: Simulating precipitation decline under a Mediterranean deciduous Oak forest: effects on isoprene seasonal emissions and predictions under climatic scenarios Anne-Cyrielle Genard-Zielinski, Christophe Boissard, Elena Ormeño, Juliette Lathière, Ilja M. Reiter, Henri Wortham, Jean-Philippe Orts, Brice Temine-Roussel, Bertrand Guenet, Svenja Bartsch, Thierry Gauquelin, and Catherine Fernandez Biogeosciences Discuss., doi:10.5194/bg-2017-17,2017 Manuscript under review for BG (discussion: open, 0 comments) From seasonal in situ observations on how a Mediterranean ecosystem responds to drought, a specific isoprene emission (ER) algorithm was developed, upon which 2100 projections (IPCC RCP2.6 and RCP8.5 scenarios) were made. ER were found to be mainly sensitive to soil water content, and poorly represented by current empirical emission model. Drought was found to aggravate thermal stress on ER, increase ER intensity and their frequency response to environmental conditions (present and future).

Description: Evaluating environmental drivers of spatial variability in free-living nematode assemblages along the Portuguese margin Lidia Lins, Frederik Leliaert, Torben Riehl, Sofia Pinto Ramalho, Eliana Alfaro Cordova, André Morgado Esteves, and Ann Vanreusel Biogeosciences, 14, 651-669, doi:10.5194/bg-14-651-2017, 2017 Anthropogenic impacts in the deep sea are regarded as high disturbers of the deep-sea bottom. This study focus in trying to understand the impact of disturbance in the ecosystem and how important functions, such as hydrodynamics and surface primary productivity, affect benthic organisms. Our results showed that high sediment variability due to hydrodynamics, and consequently disturbance, combined with high resource availability are probably the main factors promoting deep-sea species coexistence

Description: Small-scale variability in geomorphological settings influences mangrove-derived organic matter export in a tropical bay Geraldina Signa, Antonio Mazzola, James Kairo, and Salvatrice Vizzini Biogeosciences, 14, 617-629, doi:10.5194/bg-14-617-2017, 2017 Using a combined analytical approach (fatty acid and isotopic markers), we found that the different settings of the creeks flowing into Gazi Bay influenced the mangrove export to the adjacent seagrasses and coral reef. Given the major influence that organic matter exchange between habitats has on organic matter availability and consumption by fauna, the small-scale variability in mangrove export may have far-reaching consequences for local food webs and for the functioning of the whole ecosystem.

Description: Temperature variability in the Iberian Range since 1602 inferred from tree-ring records Ernesto Tejedor, Miguel Ángel Saz, José María Cuadrat, Jan Esper, and Martín de Luis Clim. Past, 13, 93-105, doi:10.5194/cp-13-93-2017, 2017 Through this study, and inferred from 316 series of tree-ring width, we developed a maximum temperature reconstruction that is significant for much of the Iberian Peninsula (IP). This reconstruction will not only help to understand the past climate of the IP but also serve to improve future climate change scenarios particularly affecting the Mediterranean area.

Description: Temperature variability in the Iberian Range since 1602 inferred from tree-ring records Ernesto Tejedor, Miguel Ángel Saz, José María Cuadrat, Jan Esper, and Martín de Luis Clim. Past, 13, 93-105, doi:10.5194/cp-13-93-2017, 2017 Through this study, and inferred from 316 series of tree-ring width, we developed a maximum temperature reconstruction that is significant for much of the Iberian Peninsula (IP). This reconstruction will not only help to understand the past climate of the IP but also serve to improve future climate change scenarios particularly affecting the Mediterranean area.

Description: Biome changes in Asia since the mid-Holocene – an analysis of different transient Earth system model simulations Anne Dallmeyer, Martin Claussen, Jian Ni, Xianyong Cao, Yongbo Wang, Nils Fischer, Madlene Pfeiffer, Liya Jin, Vyacheslav Khon, Sebastian Wagner, Kerstin Haberkorn, and Ulrike Herzschuh Clim. Past, 13, 107-134, doi:10.5194/cp-13-107-2017, 2017 The vegetation distribution in eastern Asia is supposed to be very sensitive to climate change. Since proxy records are scarce, hitherto a mechanistic understanding of the past spatio-temporal climate–vegetation relationship is lacking. To assess the Holocene vegetation change, we forced the diagnostic biome model BIOME4 with climate anomalies of different transient climate simulations.

Description: Biome changes in Asia since the mid-Holocene – an analysis of different transient Earth system model simulations Anne Dallmeyer, Martin Claussen, Jian Ni, Xianyong Cao, Yongbo Wang, Nils Fischer, Madlene Pfeiffer, Liya Jin, Vyacheslav Khon, Sebastian Wagner, Kerstin Haberkorn, and Ulrike Herzschuh Clim. Past, 13, 107-134, doi:10.5194/cp-13-107-2017, 2017 The vegetation distribution in eastern Asia is supposed to be very sensitive to climate change. Since proxy records are scarce, hitherto a mechanistic understanding of the past spatio-temporal climate–vegetation relationship is lacking. To assess the Holocene vegetation change, we forced the diagnostic biome model BIOME4 with climate anomalies of different transient climate simulations.

Description: Using street view imagery for 3D survey of rock slope failures Jérémie Voumard, Antonio Abellan, Pierrick Nicolet, Marie-Aurélie Chanut, Marc-Henri Derron, and Michel Jaboyedoff Nat. Hazards Earth Syst. Sci. Discuss., doi:10.5194/nhess-2017-49,2017 Manuscript under review for NHESS (discussion: open, 0 comments) We discuss here the challenges and limitations on surveying rock slope failures using 3D reconstruction from images acquired from Street View Imagery (SVI) and processed with modern photogrammetric workflows. Despite some clear limitations and challenges, this manuscript demonstrates that this original approach might allow obtaining preliminary 3D models of an area without on-field images. Furthermore, the pre-failure topography can be obtained for sites where it would not be available otherwise.

Description: Using street view imagery for 3D survey of rock slope failures Jérémie Voumard, Antonio Abellan, Pierrick Nicolet, Marie-Aurélie Chanut, Marc-Henri Derron, and Michel Jaboyedoff Nat. Hazards Earth Syst. Sci. Discuss., doi:10.5194/nhess-2017-49,2017 Manuscript under review for NHESS (discussion: open, 0 comments) We discuss here the challenges and limitations on surveying rock slope failures using 3D reconstruction from images acquired from Street View Imagery (SVI) and processed with modern photogrammetric workflows. Despite some clear limitations and challenges, this manuscript demonstrates that this original approach might allow obtaining preliminary 3D models of an area without on-field images. Furthermore, the pre-failure topography can be obtained for sites where it would not be available otherwise.

Description: A simple method for retrieving significant wave height from Dopplerized X-band radar Ruben Carrasco, Michael Streßer, and Jochen Horstmann Ocean Sci., 13, 95-103, doi:10.5194/os-13-95-2017, 2017 The significant wave height (Hs) is one of the most relevant parameters to describe a sea state statistically. This parameter is commonly monitored by measurement devices placed in the water (wave rider buoy, ADCP), which require expensive maintenance. In this study, X-band radar, generally used for ship navigation, was modified to measure water particle speeds using the Doppler effect. Based on the obtained data, a simple method is introduced to remotely estimate Hs with a reasonable accuracy.

Description: A simple method for retrieving significant wave height from Dopplerized X-band radar Ruben Carrasco, Michael Streßer, and Jochen Horstmann Ocean Sci., 13, 95-103, doi:10.5194/os-13-95-2017, 2017 The significant wave height (Hs) is one of the most relevant parameters to describe a sea state statistically. This parameter is commonly monitored by measurement devices placed in the water (wave rider buoy, ADCP), which require expensive maintenance. In this study, X-band radar, generally used for ship navigation, was modified to measure water particle speeds using the Doppler effect. Based on the obtained data, a simple method is introduced to remotely estimate Hs with a reasonable accuracy.

Description: Continuum model of wave propagation in fragmented media: linear damping approximation Maxim Khudyakov, Arcady V. Dyskin, and Elena Pasternak Nonlin. Processes Geophys. Discuss., doi:10.5194/npg-2017-3,2017 Manuscript under review for NPG (discussion: open, 0 comments) In order to assess energy loss during wave propagation in fragmented media, an impact model is proposed. The proposed model can be expressed by or used together with other linear damping models, which is important for the determination of mechanical characteristics of such media and mineral exploration.

Description: Continuum model of wave propagation in fragmented media: linear damping approximation Maxim Khudyakov, Arcady V. Dyskin, and Elena Pasternak Nonlin. Processes Geophys. Discuss., doi:10.5194/npg-2017-3,2017 Manuscript under review for NPG (discussion: open, 0 comments) In order to assess energy loss during wave propagation in fragmented media, an impact model is proposed. The proposed model can be expressed by or used together with other linear damping models, which is important for the determination of mechanical characteristics of such media and mineral exploration.

Description: Book review: Wildlife in the Anthropocene – Conservation after Nature Isabelle Arpin Geogr. Helv., 72, 79-80, doi:10.5194/gh-72-79-2017, 2017 No abstract available.

Description: The Future of Earth Observation in Hydrology Matthew F. McCabe, Matthew Rodell, Douglas E. Alsdorf, Diego G. Miralles, Remko Uijlenhoet, Wolfgang Wagner, Arko Lucieer, Rasmus Houborg, Niko E. C. Verhoest, Trenton E. Franz, Jiancheng Shi, Huilin Gao, and Eric F. Wood Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2017-54,2017 Manuscript under review for HESS (discussion: open, 0 comments) We examine the opportunities and challenges that technological advances in Earth observation will present to the hydrological community. From advanced space-based sensors, to unmanned aerial vehicles and ground-based distributed networks, these emergent systems are set to revolutionise our understanding and interpretation of hydrological and related processes.

Description: The Future of Earth Observation in Hydrology Matthew F. McCabe, Matthew Rodell, Douglas E. Alsdorf, Diego G. Miralles, Remko Uijlenhoet, Wolfgang Wagner, Arko Lucieer, Rasmus Houborg, Niko E. C. Verhoest, Trenton E. Franz, Jiancheng Shi, Huilin Gao, and Eric F. Wood Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2017-54,2017 Manuscript under review for HESS (discussion: open, 0 comments) We examine the opportunities and challenges that technological advances in Earth observation will present to the hydrological community. From advanced space-based sensors, to unmanned aerial vehicles and ground-based distributed networks, these emergent systems are set to revolutionise our understanding and interpretation of hydrological and related processes.

Description: A reconstruction of 1 August 1674 thunderstorms over the Low Countries Gerard van der Schrier and Rob Groenland Nat. Hazards Earth Syst. Sci., 17, 157-170, doi:10.5194/nhess-17-157-2017, 2017 On 1 August 1674, very severe thunderstorms occurred along a squall line from northern France to the northern parts of Holland, where damages were particularly severe. Using reported and pictured observations of damages, a reconstruction of this storm is made and an interpretation using modern meteorological concepts is given. Special attention is given to the city of Utrecht, which was hit hardest and where the impact of this storm is still recognisable in the cityscape.

Description: Synoptic fluctuation of the Taiwan Warm Current in winter on the East China Sea shelf Jiliang Xuan, Daji Huang, Thomas Pohlmann, Jian Su, Bernhard Mayer, Ruibin Ding, and Feng Zhou Ocean Sci., 13, 105-122, doi:10.5194/os-13-105-2017, 2017 Research on the summer TWC has been conducted previously; however, the spatial structure and temporal variation of the winter TWC are less known due to its weak mean velocity. Therefore, FVCOM was used to evaluate the spatial patterns of TWC synoptic fluctuations. We observed that the TWC fluctuations appear mainly to the north of Taiwan and in the inshore area. Our results will be useful in the dynamical understanding of the winter TWC and its impact on cross-shore transport.

Description: Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol Nga Lee Ng, Steven S. Brown, Alexander T. Archibald, Elliot Atlas, Ronald C. Cohen, John N. Crowley, Douglas A. Day, Neil M. Donahue, Juliane L. Fry, Hendrik Fuchs, Robert J. Griffin, Marcelo I. Guzman, Hartmut Herrmann, Alma Hodzic, Yoshiteru Iinuma, José L. Jimenez, Astrid Kiendler-Scharr, Ben H. Lee, Deborah J. Luecken, Jingqiu Mao, Robert McLaren, Anke Mutzel, Hans D. Osthoff, Bin Ouyang, Benedicte Picquet-Varrault, Ulrich Platt, Havala O. T. Pye, Yinon Rudich, Rebecca H. Schwantes, Manabu Shiraiwa, Jochen Stutz, Joel A. Thornton, Andreas Tilgner, Brent J. Williams, and Rahul A. Zaveri Atmos. Chem. Phys., 17, 2103-2162, doi:10.5194/acp-17-2103-2017, 2017 Oxidation of biogenic volatile organic compounds by NO 3 is an important interaction between anthropogenic and natural emissions. This review results from a June 2015 workshop and includes the recent literature on kinetics, mechanisms, organic aerosol yields, and heterogeneous chemistry; advances in analytical instrumentation; the current state NO 3 -BVOC chemistry in atmospheric models; and critical needs for future research in modeling, field observations, and laboratory studies.

Description: Measurements of sub-3 nm particles using a particle size magnifier in different environments: from clean mountain top to polluted megacities Jenni Kontkanen, Katrianne Lehtipalo, Lauri Ahonen, Juha Kangasluoma, Hanna E. Manninen, Jani Hakala, Clémence Rose, Karine Sellegri, Shan Xiao, Lin Wang, Ximeng Qi, Wei Nie, Aijun Ding, Huan Yu, Shanhu Lee, Veli-Matti Kerminen, Tuukka Petäjä, and Markku Kulmala Atmos. Chem. Phys., 17, 2163-2187, doi:10.5194/acp-17-2163-2017, 2017 The concentrations of ~1–3 nm particles were investigated at nine sites around the world. Sub-3 nm particle concentrations were highest at the sites with strong anthropogenic influence. Electrically neutral particles dominated sub-3 nm particle concentrations in polluted environments and in boreal forest during spring and summer. Sub-3 nm particle concentrations were observed to be determined by the availability of precursor vapors rather than the sink caused by preexisting aerosol particles.

Description: Laser Ablation ICP-MS of Size-Segregated Atmospheric Particles Collected with a MOUDI Cascade Impactor: A Proof of Concept Marin S. Robinson, Irena Grgić, Vid S. Šelih, Martin Šala, Marsha Bitsui, and Johannes T. van Elteren Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2016-411,2017 Manuscript under review for AMT (discussion: open, 0 comments) Knowing the size and elemental composition of airborne particles is necessary to understand their impact on human health. A widely used instrument for collecting size-segregated particles is the multi-orifice uniform deposit impactor (MOUDI). Laser ablation ICP-MS in imaging mode provided multi-elemental analysis of size-segregated particles with excellent sensitivity. The maps generated offered insights regarding the uniformity of the elemental distribution.

Description: Post-processing to remove residual clouds from aerosol optical depth retrieved using the Advanced Along Track Scanning Radiometer Larisa Sogacheva, Pekka Kolmonen, Timo H. Virtanen, Edith Rodriguez, Giulia Saponaro, and Gerrit de Leeuw Atmos. Meas. Tech., 10, 491-505, doi:10.5194/amt-10-491-2017, 2017 Clouds reflect solar light much more strongly than aerosol particles. Therefore, the retrieval of aerosol optical depth is usually only attempted over cloud-free areas. A very strict cloud detection scheme has to be applied to remove all cloudy pixels. However, often not all clouds are detected. To remove possibly cloud-contaminated pixels, a cloud post-processing algorithm has been designed, which effectively solves the problem and results in smoother AOD maps and improved validation results.

Description: MUSICA MetOp/IASI {H 2 O, δ D} pair retrieval simulations for validating tropospheric moisture pathways in atmospheric models Matthias Schneider, Christian Borger, Andreas Wiegele, Frank Hase, Omaira E. García, Eliezer Sepúlveda, and Martin Werner Atmos. Meas. Tech., 10, 507-525, doi:10.5194/amt-10-507-2017, 2017 The characteristics of {H 2 O, δ D} pair space-based remote sensing data depend on the atmospheric and surface conditions, which compromises their usage for model evaluation studies. This paper shows how the problem can be overcome by simulating MUSICA MetOp/IASI {H 2 O, δ D} remote sensing products for any given model atmosphere. The remote sensing retrieval simulator is freely provided as a MATLAB and Python routine.

Description: Amplification of global warming through pH-dependence of DMS-production simulated with a fully coupled Earth system model Jörg Schwinger, Jerry Tjiputra, Nadine Goris, Katharina Six, Alf Kirkevåg, Øyvind Seland, Christoph Heinze, and Tatiana Ilyina Biogeosciences Discuss., doi:10.5194/bg-2017-33,2017 Manuscript under review for BG (discussion: open, 0 comments) Transient global warming under the high emission scenario RCP8.5 is amplified by up to 6 % if a pH-dependency of marine DMS-production is assumed. Importantly, this additional warming is not spatially homogeneous but shows a pronounced north-south gradient. Over the Antarctic continent, the additional warming is almost twice the global average. In the Southern Ocean we find a small DMS-climate feedback that counteracts the original reduction of DMS-production due to ocean acidification.

Description: Isoprene emission and photosynthesis during heat waves and drought in black locust Ines Bamberger, Nadine K. Ruehr, Michael Schmitt, Andreas Gast, Georg Wohlfahrt, and Almut Arneth Biogeosciences Discuss., doi:10.5194/bg-2017-32,2017 Manuscript under review for BG (discussion: open, 0 comments) We studied the effects of two weeks long summer heat waves and drought on photosynthesis and isoprene emissions in black locust trees. While photosynthesis decreased, isoprene emission increased sharply in response to heat and heat-drought stress. Comparing isoprene emissions at the same temperature, however, demonstrated that stressed trees emitted less isoprene than expected. This reveals that in order to predict isoprene emissions during heat waves, model parameters need to be re-evaluated.

Description: Evaluation of Turbulence Measurement Techniques from a Single Doppler Lidar Timothy A. Bonin, Aditya Choukulkar, W. Alan Brewer, Scott P. Sandberg, Ann M. Weickmann, Yelena Pichugina, Robert M. Banta, Steven P. Oncley, and Daniel E. Wolfe Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2017-35,2017 Manuscript under review for AMT (discussion: open, 0 comments) Three different techniques for measuring turbulent quantities from a single Doppler lidar are evaluated against in situ observations for verification. A six-beam method generally produced the most accurate measurements of the turbulence quantities evaluated. Generally, turbulence kinetic energy can be accurately measured across all scales from a Doppler lidar. Individual velocity variances are measured less accurately, and velocity covariances are shown to be difficult to measure.

Description: Strato-mesospheric carbon monoxide profiles above Kiruna, Sweden (67.8 ° N, 20.4 ° E), since 2008 Niall J. Ryan, Mathias Palm, Uwe Raffalski, Richard Larsson, Gloria Manney, Luis Millán, and Justus Notholt Earth Syst. Sci. Data, 9, 77-89, doi:10.5194/essd-9-77-2017, 2017 We present a self-consistent data set of carbon monoxide (CO) in the Arctic middle atmosphere above Kiruna, Sweden, between 2008 and 2015. The data are retrieved from measurements made by the ground-based radiometer, KIMRA, and are compared to coincident CO data measured by the satellite instrument MLS. KIMRA shows agreement with MLS over the altitude range in which KIMRA is sensitive (48–84 km) and the data show the signatures of dynamic processes such as sudden stratospheric warmings.

Description: A Global Model of Predicted Peregrine Falcon ( Falco peregrinus ) Distribution with Open Source GIS Code and 104 Open Access Layers for use by the global public Sumithra Sriram and Falk Huettmann Earth Syst. Sci. Data Discuss., doi:10.5194/essd-2016-65,2017 Manuscript under review for ESSD (discussion: open, 0 comments) Using the best-available open access data from GBIF, and a compilation of over a hundred high resolution global GIS layers that incorporated variables such as biological, climatic, and socio-economic predictors, we built the first generalizable model ever obtained using 104 predictors on a 1 km scale, predicting the potential ecological niche of Peregrine Falcons ( Falco peregrinus ) around the world. The GIS layers can be found at https://scholarworks.alaska.edu/handle/11122/7151.

Description: Soil Moisture Estimation Based on Probabilistic Inversion over Heterogeneous Vegetated Fields Using Airborne PLMR Brightness Temperature Chunfeng Ma, Xin Li, and Shuguo Wang Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2017-34,2017 Manuscript under review for HESS (discussion: open, 0 comments) We present a SM estimation based on the combination of Bayesian probabilistic inversion with airborne L‐band radiometer observations. The work has obtained a desirable SM estimation and uncertainty quantification, which may offer an insight into the future SM inversion based on passive microwave remote sensing.

Description: A GIS-based monitoring and early warning system for cover-collapse sinkholes in karst terrane in Wuhan, China Li Xueping, Xiao Shangde, Tang Huiming, and Peng Jinsheng Nat. Hazards Earth Syst. Sci. Discuss., doi:10.5194/nhess-2017-22,2017 Manuscript under review for NHESS (discussion: open, 0 comments) A GIS-based monitoring and early warning system for cover-collapse sinkholes in karst terrane in Wuhan, China has been established so as to reduce disastrous losses caused by karst collapse. Three types warning criteria for cover-collapse sinkholes has been established in the system. Three levels have been used to classify the warning grade. Level I refers to the stat safe ; level II refers becoming dangerous ; and level III refers dangerous .

Description: North Atlantic deep water formation and AMOC in CMIP5 models Céline Heuzé Ocean Sci. Discuss., doi:10.5194/os-2017-2,2017 Manuscript under review for OS (discussion: open, 0 comments) Climate models are the best tool available to estimate the ocean’s response to climate change, notably sea level rise. To trust the models, we need to compare them to the real ocean in key areas. Here we do so in the North Atlantic, where deep waters form, and show that inaccurate location, extent and frequency of the formation impact the representation of the global ocean circulation and how much heat enters the Arctic. We also study the causes of the errors, in order to improve future models.

Description: North Atlantic deep water formation and AMOC in CMIP5 models Céline Heuzé Ocean Sci. Discuss., doi:10.5194/os-2017-2,2017 Manuscript under review for OS (discussion: open, 0 comments) Climate models are the best tool available to estimate the ocean’s response to climate change, notably sea level rise. To trust the models, we need to compare them to the real ocean in key areas. Here we do so in the North Atlantic, where deep waters form, and show that inaccurate location, extent and frequency of the formation impact the representation of the global ocean circulation and how much heat enters the Arctic. We also study the causes of the errors, in order to improve future models.

Description: Formation of secondary organic aerosols from the ozonolysis of dihydrofurans Yolanda Diaz-de-Mera, Alfonso Aranda, Larisa Bracco, Diana Rodriguez, and Ana Rodriguez Atmos. Chem. Phys., 17, 2347-2357, doi:10.5194/acp-17-2347-2017, 2017 Criegee intermediates are involved in the formation of secondary organic aerosols. How? Recent works show that they contribute to the oxidation of SO 2 to SO 3 . We have found that the studied ozonolysis reactions only led to nucleation in the presence of SO 2 , which behaved as a catalyst. So the role of SO 2 to form SOA depends on the structure of the alkene. For these reactions, the formation of low-volatility organic acid is expected to be responsible for nucleation, since SO 3 was not released.

Description: The recent increase of atmospheric methane from 10 years of ground-based NDACC FTIR observations since 2005 Whitney Bader, Benoît Bovy, Stephanie Conway, Kimberly Strong, Dan Smale, Alexander J. Turner, Thomas Blumenstock, Chris Boone, Martine Collaud Coen, Ancelin Coulon, Omaira Garcia, David W. T. Griffith, Frank Hase, Petra Hausmann, Nicholas Jones, Paul Krummel, Isao Murata, Isamu Morino, Hideaki Nakajima, Simon O'Doherty, Clare Paton-Walsh, John Robinson, Rodrigue Sandrin, Matthias Schneider, Christian Servais, Ralf Sussmann, and Emmanuel Mahieu Atmos. Chem. Phys., 17, 2255-2277, doi:10.5194/acp-17-2255-2017, 2017 An increase of 0.31 ± 0.03 % year −1 of atmospheric methane is reported using 10 years of solar observations performed at 10 ground-based stations since 2005. These trend agree with a GEOS-Chem-tagged simulation that accounts for the contribution of each emission source and one sink in the total methane. The GEOS-Chem simulation shows that anthropogenic emissions from coal mining and gas and oil transport and exploration have played a major role in the increase methane since 2005.

Description: Origin and variability of volatile organic compounds observed at an Eastern Mediterranean background site (Cyprus) Cécile Debevec, Stéphane Sauvage, Valérie Gros, Jean Sciare, Michael Pikridas, Iasonas Stavroulas, Thérèse Salameh, Thierry Leonardis, Vincent Gaudion, Laurence Depelchin, Isabelle Fronval, Roland Sarda-Esteve, Dominique Baisnée, Bernard Bonsang, Chrysanthos Savvides, Mihalis Vrekoussis, and Nadine Locoge Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1178,2017 Manuscript under review for ACP (discussion: open, 0 comments) An intensive field campaign was conducted in March 2015 in the Eastern Mediterranean region, at a background site of Cyprus. we performed a detailed analysis of the chemical composition of air masses in gas and aerosol phase and we applied a source apportionment analysis in order to identify the various origins of VOCs. The results suggest that VOCs are mainly of biogenic and regional background origins.

Description: Abundances of isotopologues and calibration of CO 2 greenhouse gas measurements Pieter P. Tans, Andrew M. Crotwell, and Kirk W. Thoning Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2017-34,2017 Manuscript under review for AMT (discussion: open, 0 comments) We have developed a method to calculate the fractional distribution of CO 2 across all of its component isotopologues based on measured δ 13 C and δ 18 O values. The fractional distribution can be used with known total CO 2 to calculate each component isotopologue individually, in units of mole fraction. The technique is applicable to any molecule where isotopologue-specific values are desired. We used it with a new CO 2 calibration system to account for isotopic differences among the primary CO 2 standards that define the WMO X2007 CO 2 in air calibration scale and between the primary standards and standards in subsequent levels of the calibration hierarchy. The new calibration system uses multiple laser spectroscopic techniques to measure amount of substance fractions (in mole fraction units) of the three major CO 2 isotopologues ( 16 O 12 C 16 O, 16 O 13 C 16 O, and 18 O 12 C 16 O) individually. The three measured values are then combined into total CO 2 (accounting for the rare unmeasured isotopologues), δ 13 C, and δ 18 O values. The new calibration system significantly improves our ability to transfer the WMO CO 2 calibration scale with low uncertainty through our role as the World Meteorological Organization Global Atmosphere Watch Central Calibration Laboratory for CO 2 . Our current estimates for reproducibility of the new calibration system are ±0.01 μmol mol −1 CO 2 , ±0.2 ‰ δ 13 C, and ±0.2 ‰ δ 18 O, all at 68 % confidence interval (CI).

Description: Observations and model simulations of snow albedo reduction in seasonal snow due to insoluble light-absorbing particles during 2014 Chinese survey Xin Wang, Wei Pu, Yong Ren, Xuelei Zhang, Xueying Zhang, Jinsen Shi, Hongchun Jin, Mingkai Dai, and Quanliang Chen Atmos. Chem. Phys., 17, 2279-2296, doi:10.5194/acp-17-2279-2017, 2017 A 2014 snow survey was performed across northeastern China to analyze light absorption of ILAPs in seasonal snow, and modeling studies were conducted to compare snow albedo reduction due to assumptions of internal–external mixing of BC in snow and different snow grain shapes. The results show that the simulated snow albedos from both SAMDS and SNICAR agree well with the observed values at low ILAP mixing ratios, but they tend to be higher than surface observations at high ILAP mixing ratios.

Description: In situ chemical measurement of individual cloud residue particles at a mountain site, South China Qinhao Lin, Guohua Zhang, Long Peng, Xinhui Bi, Xinming Wang, Fred J. Brechtel, Mei Li, Duohong Chen, Ping'an Peng, Guoying Sheng, and Zhen Zhou Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-23,2017 Manuscript under review for ACP (discussion: open, 0 comments) A ground-based counterflow virtual impactor coupled with a single-particle aerosol mass spectrometer (SPAMS) was used to assess the mixing state of individual cloud residue particles. Abundant aged EC cloud residues that internally mixed with inorganic salts were found in air masses from northerly polluted areas. K-rich cloud residues significantly increased within southwesterly air masses. This study increases our understanding of the impacts of aerosols on cloud droplets in South China.

Description: Quantifying and improving the performance of the Laser Ablation Aerosol Particle Time of Flight Mass Spectrometer (LAAPToF) instrument Maria A. Zawadowicz, Sara Lance, John T. Jayne, Philip Croteau, Douglas R. Worsnop, Fabian Mahrt, Thomas Leisner, and Daniel J. Cziczo Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2017-1,2017 Manuscript under review for AMT (discussion: open, 0 comments) Single Particle Mass Spectrometers (SPMSs) are instruments that detect single aerosol particles, size them and provide their mass spectra. Laser Ablation Aerosol Particle Time of Flight Mass Spectrometer (LAAPToF) is the newest commercial addition to this instrument family. In this paper, we quantify its initial performance and describe simple hardware changes that resulted in an improvement in optical particle counting efficiency. We also discuss LAAPToF in context of other SPMS instruments.

Description: VHF antenna pattern characterization by the observation of meteor head echoes Toralf Renkwitz, Carsten Schult, and Ralph Latteck Atmos. Meas. Tech., 10, 527-535, doi:10.5194/amt-10-527-2017, 2017 The knowledge of the actual radiation pattern is crucial for the analysis of radar echoes and is also an important indicator of the radar's health status. The method described here allows the radiation pattern to be characterized by observing meteor head echoes. In contrast to previous studies we generate angular occurrence maps of meteor trajectory points for periods of normal and limited radar functionality to derive the radiation pattern and compare them thorough simulation results.

Description: Precipitable Water Characteristics during the 2013 Colorado Flood using Ground-Based GPS Measurements Hannah K. Huelsing, Junhong Wang, Carl Mears, and John J. Braun Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2016-414,2017 Manuscript under review for AMT (discussion: open, 0 comments) The precipitable water (PW) was examined for the 2013 Colorado Flood to determine how climatologically abnormal this event was. The seasonal PW maximum extended into early September and the September monthly mean PW exceeded the 99 th percentile of climatology with a value 25 % higher than the 40 year climatology. The above normal, near saturation PW values during the flood were the result of large-scale moisture transport into Colorado from the eastern tropical Pacific and the Gulf of Mexico.

Description: Abundances of isotopologues and calibration of CO 2 greenhouse gas measurements Pieter P. Tans, Andrew M. Crotwell, and Kirk W. Thoning Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2017-34,2017 Manuscript under review for AMT (discussion: open, 0 comments) We have developed a method to calculate the fractional distribution of CO 2 across all of its component isotopologues based on measured δ 13 C and δ 18 O values. The fractional distribution can be used with known total CO 2 to calculate each component isotopologue individually, in units of mole fraction. The technique is applicable to any molecule where isotopologue-specific values are desired. We used it with a new CO 2 calibration system to account for isotopic differences among the primary CO 2 standards that define the WMO X2007 CO 2 in air calibration scale and between the primary standards and standards in subsequent levels of the calibration hierarchy. The new calibration system uses multiple laser spectroscopic techniques to measure amount of substance fractions (in mole fraction units) of the three major CO 2 isotopologues ( 16 O 12 C 16 O, 16 O 13 C 16 O, and 18 O 12 C 16 O) individually. The three measured values are then combined into total CO 2 (accounting for the rare unmeasured isotopologues), δ 13 C, and δ 18 O values. The new calibration system significantly improves our ability to transfer the WMO CO 2 calibration scale with low uncertainty through our role as the World Meteorological Organization Global Atmosphere Watch Central Calibration Laboratory for CO 2 . Our current estimates for reproducibility of the new calibration system are ±0.01 μmol mol −1 CO 2 , ±0.2 ‰ δ 13 C, and ±0.2 ‰ δ 18 O, all at 68 % confidence interval (CI).

Description: Quantifying and improving the performance of the Laser Ablation Aerosol Particle Time of Flight Mass Spectrometer (LAAPToF) instrument Maria A. Zawadowicz, Sara Lance, John T. Jayne, Philip Croteau, Douglas R. Worsnop, Fabian Mahrt, Thomas Leisner, and Daniel J. Cziczo Atmos. Meas. Tech. Discuss., doi:10.5194/amt-2017-1,2017 Manuscript under review for AMT (discussion: open, 0 comments) Single Particle Mass Spectrometers (SPMSs) are instruments that detect single aerosol particles, size them and provide their mass spectra. Laser Ablation Aerosol Particle Time of Flight Mass Spectrometer (LAAPToF) is the newest commercial addition to this instrument family. In this paper, we quantify its initial performance and describe simple hardware changes that resulted in an improvement in optical particle counting efficiency. We also discuss LAAPToF in context of other SPMS instruments.

Description: Comparison of four inverse modelling systems applied to the estimation of HFC-125, HFC-134a and SF 6 emissions over Europe Dominik Brunner, Tim Arnold, Stephan Henne, Alistair Manning, Rona L. Thompson, Michela Maione, Simon O'Doherty, and Stefan Reimann Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-19,2017 Manuscript under review for ACP (discussion: open, 0 comments) Hydrofluorocarbons (HFCs) and SF 6 are industrially produced gases with a large greenhouse gas warming potential. In this study, we estimated the emissions of HFCs and SF 6 over Europe by combining measurements at three background stations with four different models systems. We identified significant differences between our estimates and nationally reported numbers, but also found that the network of only 3 sites in Europe is insufficient to reliably attribute emissions to individual countries.

Description: Atmospheric CO 2 observations and models suggest strong carbon uptake by forests in New Zealand Kay Steinkamp, Sara E. Mikaloff Fletcher, Gordon Brailsford, Dan Smale, Stuart Moore, Elizabeth D. Keller, W. Troy Baisden, Hitoshi Mukai, and Britton B. Stephens Atmos. Chem. Phys., 17, 47-76, doi:10.5194/acp-17-47-2017, 2017 The exchange of carbon dioxide between the land biosphere in New Zealand and the atmosphere is estimated by combining measurements of the concentration of the gas in the air with model simulations of atmospheric circulation. The results indicate that over the study period of 2011–2013, New Zealand is a larger net sink for CO 2 than estimated in the National Inventory Report. Regions in the western South Island, especially those covered predominantly by forests, contribute the most to this signal.

Description: Air quality improvement in a megacity: implications from 2015 Beijing Parade Blue pollution control actions Wen Xu, Wei Song, Yangyang Zhang, Xuejun Liu, Lin Zhang, Yuanhong Zhao, Duanyang Liu, Aohan Tang, Daowei Yang, Dandan Wang, Zhang Wen, Yuepeng Pan, David Fowler, Jeffrey L. Collett Jr., Jan Willem Erisman, Keith Goulding, Yi Li, and Fusuo Zhang Atmos. Chem. Phys., 17, 31-46, doi:10.5194/acp-17-31-2017, 2017 This paper evaluates the effectiveness of emission control measures implemented in Beijing during the Parade Blue period by integrating our own results, official-released data and modeling data. We demonstrate that emission control measures make a major contribution to air quality improvement in Beijing and surrounding regions. We conclude a joint local and regional control of secondary aerosol precursors to be key to curbing air pollution in Beijing.

Description: Simultaneous measurements of new particle formation in 1-second time resolution at a street site and a rooftop site Yujiao Zhu, Caiqing Yan, Renyi Zhang, Zifa Wang, Mei Zheng, Huiwang Gao, Yang Gao, and Xiaohong Yao Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1143,2017 Manuscript under review for ACP (discussion: open, 0 comments) In this paper we use two identical FMPS for simultaneously measuring particle number size distributions at a street site and a rooftop site. The street canyon likely exerts distinct seasonal effects on new particle formation (NPF) because of on-road vehicle emissions: reduced NPF in spring but enhanced NPF in winter. The oxidization of biogenic organics plays a role in growing new particles. This study contributes to the understanding of enhanced NPF and new particles growth in the atmosphere.

Description: Improved provincial emission inventory and speciation profiles of anthropogenic non-methane volatile organic compounds: a case study for Jiangsu, China Yu Zhao, Pan Mao, Yaduan Zhou, Yang Yang, Jie Zhang, Shekou Wang, Yanping Dong, Fangjian Xie, Yiyong Yu, and Wenqing Li Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1121,2017 Manuscript under review for ACP (discussion: open, 0 comments) We improve and evaluate NMVOC emission inventory for Jiangsu. Field measurements were conducted to obtain NMVOC source profiles of typical chemical engineering processes. The emission inventory of NMVOC with chemistry profiles was developed for 2005–2014, and the uncertainties were quantified. The discrepancies between various inventories in source profiles and spatial patterns were evaluated. Chemistry transport model was applied to test the improvement of the provincial NMVOC inventory.

Description: Wintertime aerosol chemistry and haze evolution in an extremely polluted city of North China Plain: significant contribution from coal and biomass combustions Haiyan Li, Qi Zhang, Qiang Zhang, Chunrong Chen, Litao Wang, Zhe Wei, Shan Zhou, Caroline Parworth, Bo Zheng, Francesco Canonaco, André S. H. Prévôt, Ping Chen, Hongliang Zhang, and Kebin He Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1058,2017 Manuscript under review for ACP (discussion: open, 0 comments) The sources and aerosol evolution processes of the severe pollution episodes were investigated in Handan during wintertime using real-time measurements. An in-depth analysis of the data uncovered that primary emissions from coal combustion and biomass burning together with secondary formation of sulfate (mainly from SO 2 emitted by coal combustion) are important driving factors for haze evolution. Our findings provide useful insights into air pollution control in the heavily polluted regions.

Description: Global deposition of total reactive nitrogen oxides from 1996 to 2014 constrained with satellite observations of NO 2 columns Jeffrey A. Geddes and Randall V. Martin Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1100,2017 Manuscript under review for ACP (discussion: open, 0 comments) Here we apply NO 2 observations from multiple satellite records with the help of a chemical transport model to constrain the global deposition of reactive nitrogen oxides (NO y ) over the last two decades. NO y deposition decreased by up to 60 % in eastern North America, doubled in regions of East Asia, and declined by 20 % in parts of Western Europe. We also find changes in the export of NO y via atmospheric transport, with direct impacts on countries downwind of source regions.

Description: Overview of the European framework for online integrated air quality and meteorology modelling (EuMetChem) Alexander Baklanov Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1174,2017 Manuscript under review for ACP (discussion: open, 0 comments) The article provides an introduction to the COST Action ES1004 – European framework for online integrated air quality and meteorology modelling (EuMetChem) – goals and outcomes for this Special Issue "Coupled chemistry–meteorology modelling: status and relevance for numerical weather prediction, air quality and climate communities" which collects key scientific papers of EuMetChem and its collaborators from different continents.

Description: Wintertime aerosol chemistry and haze evolution in an extremely polluted city of North China Plain: significant contribution from coal and biomass combustions Haiyan Li, Qi Zhang, Qiang Zhang, Chunrong Chen, Litao Wang, Zhe Wei, Shan Zhou, Caroline Parworth, Bo Zheng, Francesco Canonaco, André S. H. Prévôt, Ping Chen, Hongliang Zhang, and Kebin He Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1058,2017 Manuscript under review for ACP (discussion: open, 0 comments) The sources and aerosol evolution processes of the severe pollution episodes were investigated in Handan during wintertime using real-time measurements. An in-depth analysis of the data uncovered that primary emissions from coal combustion and biomass burning together with secondary formation of sulfate (mainly from SO 2 emitted by coal combustion) are important driving factors for haze evolution. Our findings provide useful insights into air pollution control in the heavily polluted regions.

Description: Improved provincial emission inventory and speciation profiles of anthropogenic non-methane volatile organic compounds: a case study for Jiangsu, China Yu Zhao, Pan Mao, Yaduan Zhou, Yang Yang, Jie Zhang, Shekou Wang, Yanping Dong, Fangjian Xie, Yiyong Yu, and Wenqing Li Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1121,2017 Manuscript under review for ACP (discussion: open, 0 comments) We improve and evaluate NMVOC emission inventory for Jiangsu. Field measurements were conducted to obtain NMVOC source profiles of typical chemical engineering processes. The emission inventory of NMVOC with chemistry profiles was developed for 2005–2014, and the uncertainties were quantified. The discrepancies between various inventories in source profiles and spatial patterns were evaluated. Chemistry transport model was applied to test the improvement of the provincial NMVOC inventory.

Description: Air Stagnations for China (1985–2014): Climatological Mean Features and Trends Qianqian Huang, Xuhui Cai, Yu Song, and Tong Zhu Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1072,2017 Manuscript under review for ACP (discussion: open, 0 comments) Air stagnation is an important meteorological measurement for unfavorable air pollution conditions. Previous studies found that stagnation events are usually related to air pollution episodes. Now China is experiencing heavy air pollutions, but to our knowledge, little is known about air stagnations of this country. In this manuscript, we conducted a comprehensive investigation of air stagnation climatology in China, based on sounding and surface observations across the country.

Description: Overview of the European framework for online integrated air quality and meteorology modelling (EuMetChem) Alexander Baklanov Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1174,2017 Manuscript under review for ACP (discussion: open, 0 comments) The article provides an introduction to the COST Action ES1004 – European framework for online integrated air quality and meteorology modelling (EuMetChem) – goals and outcomes for this Special Issue "Coupled chemistry–meteorology modelling: status and relevance for numerical weather prediction, air quality and climate communities" which collects key scientific papers of EuMetChem and its collaborators from different continents.

Description: Simultaneous measurements of new particle formation in 1-second time resolution at a street site and a rooftop site Yujiao Zhu, Caiqing Yan, Renyi Zhang, Zifa Wang, Mei Zheng, Huiwang Gao, Yang Gao, and Xiaohong Yao Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1143,2017 Manuscript under review for ACP (discussion: open, 0 comments) In this paper we use two identical FMPS for simultaneously measuring particle number size distributions at a street site and a rooftop site. The street canyon likely exerts distinct seasonal effects on new particle formation (NPF) because of on-road vehicle emissions: reduced NPF in spring but enhanced NPF in winter. The oxidization of biogenic organics plays a role in growing new particles. This study contributes to the understanding of enhanced NPF and new particles growth in the atmosphere.

Description: Regional effects of atmospheric aerosols on temperature: an evaluation of an ensemble of on-line coupled models Rocío Baró, Laura Palacios-Peña, Alexander Baklanov, Alessandra Balzarini, Dominik Brunner, Renate Forkel, Marcus Hirtl, Luka Honzak, Juan Luis Pérez, Guido Pirovano, Roberto San José, Wolfram Schröder, Johannes Werhahn, Ralf Wolke, Rahela Zabkar, and Pedro Jiménez-Guerrero Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1157,2017 Manuscript under review for ACP (discussion: open, 0 comments) The objective of this work is to assess whether the inclusion of atmospheric aerosol-radiation-cloud interactions in an ensemble of on-line regional chemistry/climate models improves the simulation results for maximum, mean and minimum temperature over Europe. The results indicate that including these feedbacks clearly improves the spatio-temporal variability of the temperature signal simulated by current models, having broad implications for reducing the uncertainty in climate projections.

Description: A missing source of aerosols in Antarctica – beyond long-range transport, phytoplankton, and photochemistry Michael R. Giordano, Lars E. Kalnajs, Anita Avery, J. Douglas Goetz, Sean M. Davis, and Peter F. DeCarlo Atmos. Chem. Phys., 17, 1-20, doi:10.5194/acp-17-1-2017, 2017 This paper summarizes two field measurements of particles and gases made in coastal Antarctica and represents the first real-time composition measurements of particles in this understudied area of the world. Using the combined data from both field measurements, we find that there is a constant background of particles in coastal Antarctica and that they are mostly sulfate. Seasonal transitions from winter to spring add additional particles, and that from spring to summer adds additional sulfate.

Description: Secondary organic aerosol formation from in situ OH, O 3 , and NO 3 oxidation of ambient forest air in an oxidation flow reactor Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Amber M. Ortega, Juliane L. Fry, Steven S. Brown, Kyle J. Zarzana, William Dube, Nicholas L. Wagner, Danielle C. Draper, Lisa Kaser, Werner Jud, Thomas Karl, Armin Hansel, Cándido Gutiérrez-Montes, and Jose L. Jimenez Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1080,2017 Manuscript under review for ACP (discussion: open, 0 comments) Ambient forest air was oxidized by OH, O 3 , or NO 3 inside an oxidation flow reactor, leading to formation of particulate matter from any gaseous precursors found in the air. Closure was achieved between the amount of particulate mass formed from O 3 and NO 3 oxidation and the amount predicted from speciated gaseous precursors, which was in contrast to previous results for OH oxidation (Palm et al. ACP 2016). Elemental analysis of the particulate mass formed in the reactor is presented.

Description: Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM Cheng Zhou and Joyce E. Penner Atmos. Chem. Phys., 17, 21-29, doi:10.5194/acp-17-21-2017, 2017 Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water with increased aerosol loading may have been overestimated in climate models. Here, by simulating the same shallow, warm clouds using a global climate model (CAM5) and a cloud resolving model (CRM) which has more complete and detailed cloud physics, we show how a climate model can overestimate the aerosol cloud lifetime effect due to its simplified representation of cloud processes.

Description: Four years of atmospheric mercury records in Northwestern Patagonia (Argentina): potential sources, concentration patterns and influence of environmental variables observed at the GMOS EMMA station Maria C. Diéguez, Patricia E. Garcia, Mariantonia Bencardino, Francesco D'Amore, Jessica Castagna, Sergio Ribeiro Guevara, and Francesca Sprovieri Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1076,2017 Manuscript under review for ACP (discussion: open, 0 comments) First continuous records of gaseous elemental Hg (GEM) concentrations monitored at the GMOS EMMA monitoring station in Nahuel Huapi National Park (Northwestern Patagonia, Argentina) showed seasonal and daily variation with mean values higher during spring and winter (ca. 0.92 ng m −3 ) and higher day-time levels across all seasons. GEM levels were determined by the westerly winds and backward trajectory analysis highlighted the influence of clean oceanic air masses and volcanoes in the Andes.

Description: Regional effects of atmospheric aerosols on temperature: an evaluation of an ensemble of on-line coupled models Rocío Baró, Laura Palacios-Peña, Alexander Baklanov, Alessandra Balzarini, Dominik Brunner, Renate Forkel, Marcus Hirtl, Luka Honzak, Juan Luis Pérez, Guido Pirovano, Roberto San José, Wolfram Schröder, Johannes Werhahn, Ralf Wolke, Rahela Zabkar, and Pedro Jiménez-Guerrero Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1157,2017 Manuscript under review for ACP (discussion: open, 0 comments) The objective of this work is to assess whether the inclusion of atmospheric aerosol-radiation-cloud interactions in an ensemble of on-line regional chemistry/climate models improves the simulation results for maximum, mean and minimum temperature over Europe. The results indicate that including these feedbacks clearly improves the spatio-temporal variability of the temperature signal simulated by current models, having broad implications for reducing the uncertainty in climate projections.

Description: Photochemical aging of organic and inorganic ambient aerosol from the Potential Aerosol Mass (PAM) reactor experiment in East Asia Eunha Kang, Meehye Lee, William H. Brune, Taehyung Lee, and Joonyoung Ahn Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1133,2017 Manuscript under review for ACP (discussion: open, 0 comments) The Potential Aerosol Mass (PAM) reactor expedites slow atmospheric oxidation reactions and enables to observe chemical aging processes and determine the aerosol-forming power of an air mass. A PAM reactor was first deployed at Baengnyeong Island in the Yellow Sea and experiment results confirm the key role of SO 2 in generating secondary aerosols in northeast Asia and the contribution of organics to secondary aerosols is more variable during transport in the atmosphere.

Description: Atmospheric CO 2 observations and models suggest strong carbon uptake by forests in New Zealand Kay Steinkamp, Sara E. Mikaloff Fletcher, Gordon Brailsford, Dan Smale, Stuart Moore, Elizabeth D. Keller, W. Troy Baisden, Hitoshi Mukai, and Britton B. Stephens Atmos. Chem. Phys., 17, 47-76, doi:10.5194/acp-17-47-2017, 2017 The exchange of carbon dioxide between the land biosphere in New Zealand and the atmosphere is estimated by combining measurements of the concentration of the gas in the air with model simulations of atmospheric circulation. The results indicate that over the study period of 2011–2013, New Zealand is a larger net sink for CO 2 than estimated in the National Inventory Report. Regions in the western South Island, especially those covered predominantly by forests, contribute the most to this signal.

Description: A missing source of aerosols in Antarctica – beyond long-range transport, phytoplankton, and photochemistry Michael R. Giordano, Lars E. Kalnajs, Anita Avery, J. Douglas Goetz, Sean M. Davis, and Peter F. DeCarlo Atmos. Chem. Phys., 17, 1-20, doi:10.5194/acp-17-1-2017, 2017 This paper summarizes two field measurements of particles and gases made in coastal Antarctica and represents the first real-time composition measurements of particles in this understudied area of the world. Using the combined data from both field measurements, we find that there is a constant background of particles in coastal Antarctica and that they are mostly sulfate. Seasonal transitions from winter to spring add additional particles, and that from spring to summer adds additional sulfate.

Description: Why do general circulation models overestimate the aerosol cloud lifetime effect? A case study comparing CAM5 and a CRM Cheng Zhou and Joyce E. Penner Atmos. Chem. Phys., 17, 21-29, doi:10.5194/acp-17-21-2017, 2017 Observation-based studies have shown that the aerosol cloud lifetime effect or the increase of cloud liquid water with increased aerosol loading may have been overestimated in climate models. Here, by simulating the same shallow, warm clouds using a global climate model (CAM5) and a cloud resolving model (CRM) which has more complete and detailed cloud physics, we show how a climate model can overestimate the aerosol cloud lifetime effect due to its simplified representation of cloud processes.

Description: Air quality improvement in a megacity: implications from 2015 Beijing Parade Blue pollution control actions Wen Xu, Wei Song, Yangyang Zhang, Xuejun Liu, Lin Zhang, Yuanhong Zhao, Duanyang Liu, Aohan Tang, Daowei Yang, Dandan Wang, Zhang Wen, Yuepeng Pan, David Fowler, Jeffrey L. Collett Jr., Jan Willem Erisman, Keith Goulding, Yi Li, and Fusuo Zhang Atmos. Chem. Phys., 17, 31-46, doi:10.5194/acp-17-31-2017, 2017 This paper evaluates the effectiveness of emission control measures implemented in Beijing during the Parade Blue period by integrating our own results, official-released data and modeling data. We demonstrate that emission control measures make a major contribution to air quality improvement in Beijing and surrounding regions. We conclude a joint local and regional control of secondary aerosol precursors to be key to curbing air pollution in Beijing.

Description: Secondary organic aerosol formation from in situ OH, O 3 , and NO 3 oxidation of ambient forest air in an oxidation flow reactor Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Amber M. Ortega, Juliane L. Fry, Steven S. Brown, Kyle J. Zarzana, William Dube, Nicholas L. Wagner, Danielle C. Draper, Lisa Kaser, Werner Jud, Thomas Karl, Armin Hansel, Cándido Gutiérrez-Montes, and Jose L. Jimenez Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1080,2017 Manuscript under review for ACP (discussion: open, 0 comments) Ambient forest air was oxidized by OH, O 3 , or NO 3 inside an oxidation flow reactor, leading to formation of particulate matter from any gaseous precursors found in the air. Closure was achieved between the amount of particulate mass formed from O 3 and NO 3 oxidation and the amount predicted from speciated gaseous precursors, which was in contrast to previous results for OH oxidation (Palm et al. ACP 2016). Elemental analysis of the particulate mass formed in the reactor is presented.

Description: Four years of atmospheric mercury records in Northwestern Patagonia (Argentina): potential sources, concentration patterns and influence of environmental variables observed at the GMOS EMMA station Maria C. Diéguez, Patricia E. Garcia, Mariantonia Bencardino, Francesco D'Amore, Jessica Castagna, Sergio Ribeiro Guevara, and Francesca Sprovieri Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1076,2017 Manuscript under review for ACP (discussion: open, 0 comments) First continuous records of gaseous elemental Hg (GEM) concentrations monitored at the GMOS EMMA monitoring station in Nahuel Huapi National Park (Northwestern Patagonia, Argentina) showed seasonal and daily variation with mean values higher during spring and winter (ca. 0.92 ng m −3 ) and higher day-time levels across all seasons. GEM levels were determined by the westerly winds and backward trajectory analysis highlighted the influence of clean oceanic air masses and volcanoes in the Andes.

Description: Global deposition of total reactive nitrogen oxides from 1996 to 2014 constrained with satellite observations of NO 2 columns Jeffrey A. Geddes and Randall V. Martin Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1100,2017 Manuscript under review for ACP (discussion: open, 0 comments) Here we apply NO 2 observations from multiple satellite records with the help of a chemical transport model to constrain the global deposition of reactive nitrogen oxides (NO y ) over the last two decades. NO y deposition decreased by up to 60 % in eastern North America, doubled in regions of East Asia, and declined by 20 % in parts of Western Europe. We also find changes in the export of NO y via atmospheric transport, with direct impacts on countries downwind of source regions.

Description: Seasonal and Spatial Changes in Trace Gases over Megacities from AURA TES Observations Karen E. Cady-Pereira, Vivienne H. Payne, Jessica L. Neu, Kevin W. Bowman, Kazuyuki Miyazaki, Eloise A. Marais, Susan Kulawik, Zitely A. Tzompa-Sosa, and Jennifer D. Hegarty Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-110,2017 Manuscript under review for ACP (discussion: open, 0 comments) Air quality is a major issue for megacities. Our paper looks at satellite measurements over Mexico City and Lagos of several trace gases gases related to air quality to determine the temporal and spatial variability of these gases, and relates this variability to local conditions, such as topography, winds and biomass burning events. We find that while Mexico City is known for severe pollution events, the levels of of pollution in Lagos are much higher and more persistent.

Description: An assessment of geographical distribution of different plant functional types over North America simulated using the CLASS-CTEM modelling framework Rudra K. Shrestha, Vivek K. Arora, Joe R. Melton, and Laxmi Sushama Biogeosciences Discuss., doi:10.5194/bg-2017-35,2017 Manuscript under review for BG (discussion: open, 0 comments) Computer models of vegetation provide a tool to assess how future changes in climate may affect geographical distribution of vegetation. However, such models must first be assessed for their ability to reproduce present day geographical distribution of vegetation. Here, we assess the ability of one such dynamic vegetation model. We find that while the model is broadly successful in reproducing the geographical distribution of trees and grasses in North America some limitations remain.

Description: The Fire Modeling Intercomparison Project (FireMIP), phase 1: experimental and analytical protocols with detailed model descriptions Sam S. Rabin, Joe R. Melton, Gitta Lasslop, Dominique Bachelet, Matthew Forrest, Stijn Hantson, Jed O. Kaplan, Fang Li, Stéphane Mangeon, Daniel S. Ward, Chao Yue, Vivek K. Arora, Thomas Hickler, Silvia Kloster, Wolfgang Knorr, Lars Nieradzik, Allan Spessa, Gerd A. Folberth, Tim Sheehan, Apostolos Voulgarakis, Douglas I. Kelley, I. Colin Prentice, Stephen Sitch, Sandy Harrison, and Almut Arneth Geosci. Model Dev., 10, 1175-1197, doi:10.5194/gmd-10-1175-2017, 2017 Global vegetation models are important tools for understanding how the Earth system will change in the future, and fire is a critical process to include. A number of different methods have been developed to represent vegetation burning. This paper describes the protocol for the first systematic comparison of global fire models, which will allow the community to explore various drivers and evaluate what mechanisms are important for improving performance. It also includes equations for all models.

Description: Effects of vernal equinox solar eclipse on temperatures and wind directions in Switzerland Werner Eugster, Carmen Emmel, Sebastian Wolf, Nina Buchmann, Joseph P. McFadden, and C. David Whiteman Atmos. Chem. Phys. Discuss., https//doi.org/10.5194/acp-2017-321,2017 Manuscript under review for ACP (discussion: open, 0 comments) The effects of penumbral shading of the solar eclipse of 20 March 2015 on near-surface meteorology across Switzerland (occultation 65.8–70.1 %) was investigated. Temperature effects at 184 weather stations are put into context of temperature drops reported in the literature since 1834. A special focus is however put on wind direction effects observed at six flux sites (with 20-Hz data) and 165 meteorological stations (with 10-min resolution data). Results show the importance of local topography.

Description: Aerosol optical properties and instantaneous radiative forcing based on high temporospatial resolution CARSNET ground-based measurements over eastern China Huizheng Che, Bing Qi, Hujia Zhao, Xiangao Xia, Philippe Goloub, Oleg Dubovik, Victor Estelles, Emilio Cuevas-Agulló, Luc Blarel, Yunfei Wu, Jun Zhu, Rongguang Du, Yaqiang Wang, Hong Wang, Ke Gui, Jie Yu, Yu Zheng, Tianze Sun, Quanliang Chen, Guangyu Shi, and Xiaoye Zhang Atmos. Chem. Phys. Discuss., https//doi.org/10.5194/acp-2017-530,2017 Manuscript under review for ACP (discussion: open, 0 comments) Variations in the optical properties of aerosols and their effects on radiative forcing were investigated based on long-term synchronous observations from 2011 to 2015 over seven CARSNET adjacent urban, suburban and rural sites in the Yangtze River Delta, Eastern China. This is the first time to do the detailed, long-term, ground-based aerosol optical properties observations in metropolis scale (~10–40 km) in China to improve the aerosol retrieval and simulation performance in future.

Description: A Bayesian posterior predictive framework for weighting ensemble regional climate models Yanan Fan, Roman Olson, and Jason P. Evans Geosci. Model Dev., 10, 2321-2332, https://doi.org/10.5194/gmd-10-2321-2017, 2017 We develop a novel and principled Bayesian statistical approach to computing model weights in climate change projection ensembles of regional climate models. The approach accounts for uncertainty in model bias, trend and internal variability. The weights are easily interpretable and the ensemble weighted models are shown to provide the correct coverage and improve upon existing methods in terms of providing narrower confidence intervals for climate change projections.

Description: A Bayesian posterior predictive framework for weighting ensemble regional climate models Yanan Fan, Roman Olson, and Jason P. Evans Geosci. Model Dev., 10, 2321-2332, https://doi.org/10.5194/gmd-10-2321-2017, 2017 We develop a novel and principled Bayesian statistical approach to computing model weights in climate change projection ensembles of regional climate models. The approach accounts for uncertainty in model bias, trend and internal variability. The weights are easily interpretable and the ensemble weighted models are shown to provide the correct coverage and improve upon existing methods in terms of providing narrower confidence intervals for climate change projections.

Description: Statistical characteristics of convective wind gusts in Germany Susanna Mohr, Michael Kunz, Alexandra Richter, and Bodo Ruck Nat. Hazards Earth Syst. Sci., 17, 957-969, https://doi.org/10.5194/nhess-17-957-2017, 2017 Due to the small-scale and non-stationary nature of the convective wind gusts usually associated with thunderstorms, there is a considerable lack of knowledge regarding their characteristics and statistics. Thus, we investigated the temporal and spatial distribution, intensity, and return values of those wind events in Germany. The study constitutes a fundamental addition to an improved understanding of convective wind gusts and serves as basis for further risk assessments.

Description: Statistical characteristics of convective wind gusts in Germany Susanna Mohr, Michael Kunz, Alexandra Richter, and Bodo Ruck Nat. Hazards Earth Syst. Sci., 17, 957-969, https://doi.org/10.5194/nhess-17-957-2017, 2017 Due to the small-scale and non-stationary nature of the convective wind gusts usually associated with thunderstorms, there is a considerable lack of knowledge regarding their characteristics and statistics. Thus, we investigated the temporal and spatial distribution, intensity, and return values of those wind events in Germany. The study constitutes a fundamental addition to an improved understanding of convective wind gusts and serves as basis for further risk assessments.

Description: Reanalysis of a 10-year record (2004–2013) of seasonal mass balances at Langenferner/Vedretta Lunga, Ortler Alps, Italy Stephan Peter Galos, Christoph Klug, Fabien Maussion, Federico Covi, Lindsey Nicholson, Lorenzo Rieg, Wolfgang Gurgiser, Thomas Mölg, and Georg Kaser The Cryosphere, 11, 1417-1439, https://doi.org/10.5194/tc-11-1417-2017, 2017 Records of glacier mass balance represent important data in climate science and their uncertainties affect calculations of sea level rise and other societally relevant environmental projections. In order to reduce and quantify uncertainties in mass balance series obtained by direct glaciological measurements, we present a detailed reanalysis workflow which was applied to the 10-year record (2004 to 2013) of seasonal mass balance of Langenferner, a small glacier in the European Eastern Alps. The approach involves a methodological homogenization of available point values and the creation of pseudo-observations of point mass balance for years and locations without measurements by the application of a process-based model constrained by snow line observations. We examine the uncertainties related to the extrapolation of point data using a variety of methods and consequently present a more rigorous uncertainty assessment than is usually reported in the literature. Results reveal that the reanalyzed balance record considerably differs from the original one mainly for the first half of the observation period. For annual balances these misfits reach the order of  〉 300 kg m −2 and could primarily be attributed to a lack of measurements in the upper glacier part and to the use of outdated glacier outlines. For winter balances respective differences are smaller (up to 233 kg m −2 ) and they originate primarily from methodological inhomogeneities in the original series. Remaining random uncertainties in the reanalyzed series are mainly determined by the extrapolation of point data to the glacier scale and are on the order of ±79 kg m −2 for annual and ±52 kg m −2 for winter balances with values for single years/seasons reaching ±136 kg m −2 . A comparison of the glaciological results to those obtained by the geodetic method for the period 2005 to 2013 based on airborne laser-scanning data reveals that no significant bias of the reanalyzed record is detectable.

Description: Reanalysis of a 10-year record (2004–2013) of seasonal mass balances at Langenferner/Vedretta Lunga, Ortler Alps, Italy Stephan Peter Galos, Christoph Klug, Fabien Maussion, Federico Covi, Lindsey Nicholson, Lorenzo Rieg, Wolfgang Gurgiser, Thomas Mölg, and Georg Kaser The Cryosphere, 11, 1417-1439, https://doi.org/10.5194/tc-11-1417-2017, 2017 Records of glacier mass balance represent important data in climate science and their uncertainties affect calculations of sea level rise and other societally relevant environmental projections. In order to reduce and quantify uncertainties in mass balance series obtained by direct glaciological measurements, we present a detailed reanalysis workflow which was applied to the 10-year record (2004 to 2013) of seasonal mass balance of Langenferner, a small glacier in the European Eastern Alps. The approach involves a methodological homogenization of available point values and the creation of pseudo-observations of point mass balance for years and locations without measurements by the application of a process-based model constrained by snow line observations. We examine the uncertainties related to the extrapolation of point data using a variety of methods and consequently present a more rigorous uncertainty assessment than is usually reported in the literature. Results reveal that the reanalyzed balance record considerably differs from the original one mainly for the first half of the observation period. For annual balances these misfits reach the order of  〉 300 kg m −2 and could primarily be attributed to a lack of measurements in the upper glacier part and to the use of outdated glacier outlines. For winter balances respective differences are smaller (up to 233 kg m −2 ) and they originate primarily from methodological inhomogeneities in the original series. Remaining random uncertainties in the reanalyzed series are mainly determined by the extrapolation of point data to the glacier scale and are on the order of ±79 kg m −2 for annual and ±52 kg m −2 for winter balances with values for single years/seasons reaching ±136 kg m −2 . A comparison of the glaciological results to those obtained by the geodetic method for the period 2005 to 2013 based on airborne laser-scanning data reveals that no significant bias of the reanalyzed record is detectable.

Description: Real time analysis of insoluble particles in glacial ice using single particle mass spectrometry Matthew Osman, Maria A. Zawadowicz, Sarah B. Das, and Daniel J. Cziczo Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2017-151,2017 Manuscript under review for AMT (discussion: open, 0 comments) This study presents the first-time attempt at using time-of-flight single particle mass spectrometry (SPMS) as an emerging, online technique for measuring insoluble particles in glacial snow and ice. Using samples from two Greenlandic ice cores, we show that SPMS can constrain the aerodynamic size, composition, and relative abundance of most particulate types on a per-particle basis, reducing the preparation time and resources required of conventional, filter-based particle retrieval methods.

Description: Characterization of the Particle Emission from Ships Operating at Sea Using Unmanned Aerial Vehicles Tommaso F. Villa, Reece Brown, E. Rohan Jayaratne, L. Felipe Gonzalez, Lidia Morawska, and Zoran D. Ristovski Atmos. Meas. Tech. Discuss., https//doi.org/10.5194/amt-2017-146,2017 Manuscript under review for AMT (discussion: open, 0 comments) This research demonstrates the use of an unmanned aerial vehicle (UAV) to characterize the gaseous (CO 2 ) and particle (10–500 nm) emissions of a ship at sea. The field study was part of the research voyage The Great Barrier Reef as a significant source of climatically relevant aerosol particles on-board the RV Investigator around the Australian Great Barrier Reef. Measurements of the RV Investigator exhaust plume were carried out while the ship was operating at sea, at a steady engine load of 30 %. The UAV system was flown autonomously using several different programmed paths. These incorporated different altitudes and distances behind the ship in order to investigate the optimal position to capture the ship plume. Five flights were performed, providing a total of 27 horizontal transects perpendicular to the ship exhaust plume. Results show that the most appropriate altitude and distance to effectively capture the plume was 25 m above sea level and 20 m downwind. Particle number (PN) emission factors (EF) were calculated in terms of number of particles emitted (#) per weight of fuel consumed (Kg fuel). Fuel consumption was calculated using the simultaneous measurements of plume CO 2 concentration. Calculated EFPN were between 9.19 × 1014 and 5.15 × 1015 #∙(Kg fuel) −1 . These values are in line with those reported in the literature for ship emissions ranging from 0.2 6.2 × 1016 #∙(Kg fuel) −1 to 6.2 × 1016 #∙(Kg fuel) −1 . This UAV system successfully assessed ship emissions to derive emission factors (EFs) under real world conditions. This is significant as, for the first time, it provides a reliable, inexpensive and accessible way to assess and potentially regulate ship emissions.

Description: A decadal time series of water vapor and D / H isotope ratios above Zugspitze: transport patterns to central Europe Petra Hausmann, Ralf Sussmann, Thomas Trickl, and Matthias Schneider Atmos. Chem. Phys., 17, 7635-7651, https://doi.org/10.5194/acp-17-7635-2017, 2017 We present FTIR soundings (2005–15) of water vapor (H 2 O) and its isotope ratio (δD) at Zugspitze. Significant {H 2 O, δD} signatures are found for intercontinental transport events and stratospheric air intrusions to central Europe using backward trajectories and validation by lidar and in situ data. Our results show that {H 2 O, δD} observations at Zugspitze can serve as indicators for moisture pathways and long-range-transport events, potentially impacting central European climate and air quality.

Description: Tracking an Atmospheric River in a Warmer Climate: from Water Vapor to Economic Impacts Francina Dominguez, Sandy Dall'erba, Shuyi Huang, Andre Avelino, Ali Mehran, Huancui Hu, Arthur Schmidt, Lawrence Schick, and Dennis Lettenmaier Earth Syst. Dynam. Discuss., https//doi.org/10.5194/esd-2017-64,2017 Manuscript under review for ESD (discussion: open, 0 comments) Atmospheric rivers (ARs) account for most of the extreme flooding events in the northwestern coast of the US. In a warmer climate, ARs in this region are projected to become more frequent and intense. We present an integrated modeling system to quantify the atmospheric-hydrologic-hydraulic and economic impacts an AR event in western Washington. Our integrated modeling tool provides communities in the region a range of possible future physical and economic impacts associated with AR flooding.

Description: Estimating global cropland production from 1961 to 2010 Pengfei Han, Ning Zeng, Fang Zhao, and Xiaohui Lin Earth Syst. Dynam. Discuss., https//doi.org/10.5194/esd-2017-49,2017 Manuscript under review for ESD (discussion: open, 0 comments) Global cropland net primary production has tripled over the last fifty years. However, long-term comparisons across global croplands are scarce due to the lack of detailed management data. Here, we conducted a simulation study of global cropland production from 1961 to 2010 using VEGAS model. We modified the key parameter associated with the Green Revolution. The updated results decreased the root mean square error ~ 45 %, suggesting it is important to calibrate key parameters at regional scales.

Description: The challenge of forecasting impacts of flash floods: test of a simplified hydraulic approach and validation based on insurance claim data Guillaume Le Bihan, Olivier Payrastre, Eric Gaume, David Moncoulon, and Frederic Pons Hydrol. Earth Syst. Sci. Discuss., https//doi.org/10.5194/hess-2017-344,2017 Manuscript under review for HESS (discussion: open, 0 comments) This paper illustrates how an integrated flash flood monitoring (or forecasting) system may be designed to directly provide information on possibly flooded areas and associated impacts on a very detailed river network and over large territories. The approach is extensively tested in the regions of Alès and Draguignan, located in south-eastern France. Validation results are presented in terms of accuracy of the estimated flood extents and related impacts (based on insurance claim data).

Description: The challenge of forecasting impacts of flash floods: test of a simplified hydraulic approach and validation based on insurance claim data Guillaume Le Bihan, Olivier Payrastre, Eric Gaume, David Moncoulon, and Frederic Pons Hydrol. Earth Syst. Sci. Discuss., https//doi.org/10.5194/hess-2017-344,2017 Manuscript under review for HESS (discussion: open, 0 comments) This paper illustrates how an integrated flash flood monitoring (or forecasting) system may be designed to directly provide information on possibly flooded areas and associated impacts on a very detailed river network and over large territories. The approach is extensively tested in the regions of Alès and Draguignan, located in south-eastern France. Validation results are presented in terms of accuracy of the estimated flood extents and related impacts (based on insurance claim data).