Articles | Volume 12, issue 6
https://doi.org/10.5194/tc-12-1939-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/tc-12-1939-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Mercury in the Arctic tundra snowpack: temporal and spatial concentration patterns and trace gas exchanges
Yannick Agnan
CORRESPONDING AUTHOR
Sorbonne Université, CNRS, EPHE, UMR Metis, 75252 Paris, France
Division of Atmospheric Sciences, Desert Research Institute, Reno,
Nevada 89523, USA
Thomas A. Douglas
US Army Cold Regions Research and Engineering Laboratory, PO Box
35170, Fort Wainwright, Alaska 99709, USA
Detlev Helmig
Institute of Arctic and Alpine Research, University of Colorado,
Boulder, Colorado 80309, USA
Jacques Hueber
Institute of Arctic and Alpine Research, University of Colorado,
Boulder, Colorado 80309, USA
Daniel Obrist
CORRESPONDING AUTHOR
Department of Environmental, Earth, and Atmospheric Sciences,
University of Massachusetts, Lowell, MA 01854, USA
Division of Atmospheric Sciences, Desert Research Institute, Reno,
Nevada 89523, USA
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Brieuc F. Hardy, Clélia Van de Casteele, Louis Vandebroek, and Yannick Agnan
EGUsphere, https://doi.org/10.5194/egusphere-2026-3765, https://doi.org/10.5194/egusphere-2026-3765, 2026
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The concept of soil health is becoming increasingly popular. Yet, the way to measure it remains unclear. We developed a general framework to measure not only soil health (the relative level of an indicator with respect to soil intrinsic potential), which central for sustainable soil management, but also absolute soil quality (the state of an indicator representative of a soil function regarding an absolute maximum), which is necessary in land planning, to match land use with soil capabilities.
Noé Vandevoorde, Igor Turine, Alodie Blondel, and Yannick Agnan
SOIL, 12, 17–35, https://doi.org/10.5194/soil-12-17-2026, https://doi.org/10.5194/soil-12-17-2026, 2026
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Cover crops (CC) are known to help capture nitrates, but their role in mitigating pesticide impacts has been less studied. We evaluated how two CC densities (vs. bare soil) affected pesticide residues in soil and solution over 3 months in a greenhouse pot experiment. Our results show that well-developed CCs enhance pesticide biodegradation across a wide range of active substances, likely by sustaining active edaphic microbiota. This further confirms the role of CCs in groundwater protection.
Elisabeth Mauclet, Yannick Agnan, Catherine Hirst, Arthur Monhonval, Benoît Pereira, Aubry Vandeuren, Maëlle Villani, Justin Ledman, Meghan Taylor, Briana L. Jasinski, Edward A. G. Schuur, and Sophie Opfergelt
Biogeosciences, 19, 2333–2351, https://doi.org/10.5194/bg-19-2333-2022, https://doi.org/10.5194/bg-19-2333-2022, 2022
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Arctic warming and permafrost degradation largely affect tundra vegetation. Wetter lowlands show an increase in sedges, whereas drier uplands favor shrub expansion. Here, we demonstrate that the difference in the foliar elemental composition of typical tundra vegetation species controls the change in local foliar elemental stock and potential mineral element cycling through litter production upon a shift in tundra vegetation.
Jinyang Du, K. Arthur Endsley, Kazem Bakian Dogaheh, John S. Kimball, Mahta Moghaddam, Thomas A. Douglas, Asem Melebari, Sepehr Eskandari, Jinhyuk E. Kim, Jane Whitcomb, Yuhuan Zhao, and Sophia Henze
The Cryosphere, 20, 4277–4291, https://doi.org/10.5194/tc-20-4277-2026, https://doi.org/10.5194/tc-20-4277-2026, 2026
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Active layer thickness (ALT) is a sensitive indicator of the thawing Alaskan frozen soil, which may lead to increased greenhouse gas emissions, vegetation changes, and infrastructure damage. This study represents a multi-scale assessment of ALT spatial variations using observations including intensive field sampling, and drone, airborne and satellite remote sensing. Our study allows for improved interpretation of remote sensing and process-based ALT simulations for the changing Arctic.
Brieuc F. Hardy, Clélia Van de Casteele, Louis Vandebroek, and Yannick Agnan
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The concept of soil health is becoming increasingly popular. Yet, the way to measure it remains unclear. We developed a general framework to measure not only soil health (the relative level of an indicator with respect to soil intrinsic potential), which central for sustainable soil management, but also absolute soil quality (the state of an indicator representative of a soil function regarding an absolute maximum), which is necessary in land planning, to match land use with soil capabilities.
Christine L. Olson, Kevin Schaefer, Alyssa Azaroff, Hélène Angot, Sasiri Bandara, Thomas A. Douglas, Bo Elberling, Maria Florencia Fahnestock, Xinbin Feng, Charlotte Haugk, Gustaf Hugelius, Erfan Jahangir, Sofi Jonsson, Shichang Kang, Adam Kirkwood, Jennifer Korosi, Igor Lehnherr, Artem Lim, Rinat Manasypov, Dmitriy Moskovchenko, Mina Nasr, Daniel Obrist, David Olefeldt, Connor Olson, Oleg Pokrovsky, Laura Sereni, Sarah Shakil, M. Isabel Smith, Jens Søndergaard, Jeroen Sonke, Kasia Staniszewska, Jens Strauss, Kyra St. Pierre, Lauren Thompson, Andrey Yurtaev, Yanxu Zhang, and Scott Zolkos
Earth Syst. Sci. Data, 18, 4509–4522, https://doi.org/10.5194/essd-18-4509-2026, https://doi.org/10.5194/essd-18-4509-2026, 2026
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Permafrost regions store large amounts of mercury, a toxic pollutant that can be released as the ground warms. We combined thousands of measurements from soils, plants, water, and lake sediments into one open database to better understand where mercury is stored and how it moves. The results show clear differences among environments and reveal major data gaps, helping improve future research, monitoring, and decision-making.
Hailey Webb, Ethan Pierce, Benjamin W. Abbott, William B. Bowden, Yaping Chen, Yating Chen, Thomas A. Douglas, Joel F. Eklof, Eugénie S. Euskirchen, Moritz Langer, Isla H. Myers-Smith, Irina Overeem, Jens Strauss, Katey Walter Anthony, Kang Wang, Matthew A. Whitley, and Merritt R. Turetsky
Earth Syst. Sci. Data, 18, 3147–3164, https://doi.org/10.5194/essd-18-3147-2026, https://doi.org/10.5194/essd-18-3147-2026, 2026
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We created a database of 19,540 thawing permafrost sites across Alaska, including both abrupt and non-abrupt thaw features and explored relationships with elevation, slope, and incoming solar radiation. We use the database to show that existing ground ice maps are too coarse to predict abrupt thaw risk. This database can enhance predictions of future thaw and guide planning and adaptation strategies.
Valentina Ekimova, MacKenzie A. Nelson, Taylor Sullivan, Thomas A. Douglas, Howard E. Epstein, and Matthew G. Jull
The Cryosphere, 20, 265–283, https://doi.org/10.5194/tc-20-265-2026, https://doi.org/10.5194/tc-20-265-2026, 2026
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Permafrost beneath Arctic communities is highly sensitive to surface heat and moisture. Geophysics at four Utqiaġvik (Alaska) sites shows that infrastructure – buildings, roads, snow fences – reshapes snow and drainage, redirecting heat and water. Thaw deepens near disturbed ground, while undisturbed, vegetated terrain stays shallower or heaves. Local land use and surface conditions can outweigh regional climate signals, guiding design, maintenance, and risk planning for Arctic infrastructure.
Noé Vandevoorde, Igor Turine, Alodie Blondel, and Yannick Agnan
SOIL, 12, 17–35, https://doi.org/10.5194/soil-12-17-2026, https://doi.org/10.5194/soil-12-17-2026, 2026
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Cover crops (CC) are known to help capture nitrates, but their role in mitigating pesticide impacts has been less studied. We evaluated how two CC densities (vs. bare soil) affected pesticide residues in soil and solution over 3 months in a greenhouse pot experiment. Our results show that well-developed CCs enhance pesticide biodegradation across a wide range of active substances, likely by sustaining active edaphic microbiota. This further confirms the role of CCs in groundwater protection.
David Brodylo, Lauren V. Bosche, Ryan R. Busby, Elias J. Deeb, Thomas A. Douglas, and Juha Lemmetyinen
The Cryosphere, 19, 6127–6148, https://doi.org/10.5194/tc-19-6127-2025, https://doi.org/10.5194/tc-19-6127-2025, 2025
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We combined field-based snow depth and snow water equivalent (SWE) measurements, remote sensing data, and machine learning to estimate snow depth and SWE over a 10 km2 local scale area in Sodankylä, Finland. Associations were found for snow depth and SWE with carbon- and mineral-based forest surface soils, alongside dry and wet peatbogs. This approach to upscale field-based snow depth and SWE measurements to a local scale can be used in regions that regularly experience snowfall.
Yugo Kanaya, Roberto Sommariva, Alfonso Saiz-Lopez, Andrea Mazzeo, Theodore K. Koenig, Kaori Kawana, James E. Johnson, Aurélie Colomb, Pierre Tulet, Suzie Molloy, Ian E. Galbally, Rainer Volkamer, Anoop Mahajan, John W. Halfacre, Paul B. Shepson, Julia Schmale, Hélène Angot, Byron Blomquist, Matthew D. Shupe, Detlev Helmig, Junsu Gil, Meehye Lee, Sean C. Coburn, Ivan Ortega, Gao Chen, James Lee, Kenneth C. Aikin, David D. Parrish, John S. Holloway, Thomas B. Ryerson, Ilana B. Pollack, Eric J. Williams, Brian M. Lerner, Andrew J. Weinheimer, Teresa Campos, Frank M. Flocke, J. Ryan Spackman, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Ralf M. Staebler, Amir A. Aliabadi, Wanmin Gong, Roeland Van Malderen, Anne M. Thompson, Ryan M. Stauffer, Debra E. Kollonige, Juan Carlos Gómez Martin, Masatomo Fujiwara, Katie Read, Matthew Rowlinson, Keiichi Sato, Junichi Kurokawa, Yoko Iwamoto, Fumikazu Taketani, Hisahiro Takashima, Mónica Navarro-Comas, Marios Panagi, and Martin G. Schultz
Earth Syst. Sci. Data, 17, 4901–4932, https://doi.org/10.5194/essd-17-4901-2025, https://doi.org/10.5194/essd-17-4901-2025, 2025
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The first comprehensive dataset of tropospheric ozone over oceans/polar regions is presented, including 77 ship/buoy and 48 aircraft campaign observations (1977–2022, 0–5000 m altitude), supplemented by ozonesonde and surface data. Air masses isolated from land for 72+ hours are systematically selected as essentially oceanic. Among the 11 global regions, they show daytime decreases of 11–16 % in the tropics, while near-zero depletions are rare, unlike in the Arctic, implying different mechanisms.
Thomas A. Douglas, M. Torre Jorgenson, Taylor Sullivan, and Caiyun Zhang
The Cryosphere, 19, 3991–4009, https://doi.org/10.5194/tc-19-3991-2025, https://doi.org/10.5194/tc-19-3991-2025, 2025
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Permafrost thaw across Earth's high latitudes is leading to dramatic changes in vegetation and hydrology. We undertook a two-decade-long study on the Tanana Flats near Fairbanks, Alaska, to measure permafrost thaw and associated ground surface subsidence via field-based and remote-sensing techniques. The study identified strengths and limitations of the three methods we used to quantify permafrost thaw degradation.
Anna C. Talucci, Michael M. Loranty, Jean E. Holloway, Brendan M. Rogers, Heather D. Alexander, Natalie Baillargeon, Jennifer L. Baltzer, Logan T. Berner, Amy Breen, Leya Brodt, Brian Buma, Jacqueline Dean, Clement J. F. Delcourt, Lucas R. Diaz, Catherine M. Dieleman, Thomas A. Douglas, Gerald V. Frost, Benjamin V. Gaglioti, Rebecca E. Hewitt, Teresa Hollingsworth, M. Torre Jorgenson, Mark J. Lara, Rachel A. Loehman, Michelle C. Mack, Kristen L. Manies, Christina Minions, Susan M. Natali, Jonathan A. O'Donnell, David Olefeldt, Alison K. Paulson, Adrian V. Rocha, Lisa B. Saperstein, Tatiana A. Shestakova, Seeta Sistla, Oleg Sizov, Andrey Soromotin, Merritt R. Turetsky, Sander Veraverbeke, and Michelle A. Walvoord
Earth Syst. Sci. Data, 17, 2887–2909, https://doi.org/10.5194/essd-17-2887-2025, https://doi.org/10.5194/essd-17-2887-2025, 2025
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Wildfires have the potential to accelerate permafrost thaw and the associated feedbacks to climate change. We assembled a dataset of permafrost thaw depth measurements from burned and unburned sites contributed by researchers from across the northern high-latitude region. We estimated maximum thaw depth for each measurement, which addresses a key challenge: the ability to assess impacts of wildfire on maximum thaw depth when measurement timing varies.
Andrew O. Langford, Raul J. Alvarez II, Kenneth C. Aikin, Sunil Baidar, W. Alan Brewer, Steven S. Brown, Matthew M. Coggan, Patrick D. Cullis, Jessica Gilman, Georgios I. Gkatzelis, Detlev Helmig, Bryan J. Johnson, K. Emma Knowland, Rajesh Kumar, Aaron D. Lamplugh, Audra McClure-Begley, Brandi J. McCarty, Ann M. Middlebrook, Gabriele Pfister, Jeff Peischl, Irina Petropavlovskikh, Pamela S. Rickley, Andrew W. Rollins, Scott P. Sandberg, Christoph J. Senff, and Carsten Warneke
EGUsphere, https://doi.org/10.5194/egusphere-2024-1938, https://doi.org/10.5194/egusphere-2024-1938, 2024
Preprint withdrawn
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High ozone (O3) formed by reactions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) can harm human health and welfare. High O3 is usually associated with hot summer days, but under certain conditions, high O3 can also form under winter conditions. In this study, we describe a high O3 event that occurred in Colorado during the COVID-19 quarantine that was caused in part by the decrease in traffic, and in part by a shallow inversion created by descent of stratospheric air.
Matthew J. Rowlinson, Mat J. Evans, Lucy J. Carpenter, Katie A. Read, Shalini Punjabi, Adedayo Adedeji, Luke Fakes, Ally Lewis, Ben Richmond, Neil Passant, Tim Murrells, Barron Henderson, Kelvin H. Bates, and Detlev Helmig
Atmos. Chem. Phys., 24, 8317–8342, https://doi.org/10.5194/acp-24-8317-2024, https://doi.org/10.5194/acp-24-8317-2024, 2024
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Ethane and propane are volatile organic compounds emitted from human activities which help to form ozone, a pollutant and greenhouse gas, and also affect the chemistry of the lower atmosphere. Atmospheric models tend to do a poor job of reproducing the abundance of these compounds in the atmosphere. By using regional estimates of their emissions, rather than globally consistent estimates, we can significantly improve the simulation of ethane in the model and make some improvement for propane.
Charles E. Miller, Peter C. Griffith, Elizabeth Hoy, Naiara S. Pinto, Yunling Lou, Scott Hensley, Bruce D. Chapman, Jennifer Baltzer, Kazem Bakian-Dogaheh, W. Robert Bolton, Laura Bourgeau-Chavez, Richard H. Chen, Byung-Hun Choe, Leah K. Clayton, Thomas A. Douglas, Nancy French, Jean E. Holloway, Gang Hong, Lingcao Huang, Go Iwahana, Liza Jenkins, John S. Kimball, Tatiana Loboda, Michelle Mack, Philip Marsh, Roger J. Michaelides, Mahta Moghaddam, Andrew Parsekian, Kevin Schaefer, Paul R. Siqueira, Debjani Singh, Alireza Tabatabaeenejad, Merritt Turetsky, Ridha Touzi, Elizabeth Wig, Cathy J. Wilson, Paul Wilson, Stan D. Wullschleger, Yonghong Yi, Howard A. Zebker, Yu Zhang, Yuhuan Zhao, and Scott J. Goetz
Earth Syst. Sci. Data, 16, 2605–2624, https://doi.org/10.5194/essd-16-2605-2024, https://doi.org/10.5194/essd-16-2605-2024, 2024
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NASA’s Arctic Boreal Vulnerability Experiment (ABoVE) conducted airborne synthetic aperture radar (SAR) surveys of over 120 000 km2 in Alaska and northwestern Canada during 2017, 2018, 2019, and 2022. This paper summarizes those results and provides links to details on ~ 80 individual flight lines. This paper is presented as a guide to enable interested readers to fully explore the ABoVE L- and P-band SAR data.
Ting Wang, Buyun Du, Inke Forbrich, Jun Zhou, Joshua Polen, Elsie M. Sunderland, Prentiss H. Balcom, Celia Chen, and Daniel Obrist
Biogeosciences, 21, 1461–1476, https://doi.org/10.5194/bg-21-1461-2024, https://doi.org/10.5194/bg-21-1461-2024, 2024
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The strong seasonal increases of Hg in aboveground biomass during the growing season and the lack of changes observed after senescence in this salt marsh ecosystem suggest physiologically controlled Hg uptake pathways. The Hg sources found in marsh aboveground tissues originate from a mix of sources, unlike terrestrial ecosystems, where atmospheric GEM is the main source. Belowground plant tissues mostly take up Hg from soils. Overall, the salt marsh currently serves as a small net Hg sink.
Kevin R. Barry, Thomas C. J. Hill, Marina Nieto-Caballero, Thomas A. Douglas, Sonia M. Kreidenweis, Paul J. DeMott, and Jessie M. Creamean
Atmos. Chem. Phys., 23, 15783–15793, https://doi.org/10.5194/acp-23-15783-2023, https://doi.org/10.5194/acp-23-15783-2023, 2023
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Ice-nucleating particles (INPs) are important for the climate due to their influence on cloud properties. To understand potential land-based sources of them in the Arctic, we carried out a survey near the northernmost point of Alaska, a landscape connected to the permafrost (thermokarst). Permafrost contained high concentrations of INPs, with the largest values near the coast. The thermokarst lakes were found to emit INPs, and the water contained elevated concentrations.
Brandon Bottorff, Michelle M. Lew, Youngjun Woo, Pamela Rickly, Matthew D. Rollings, Benjamin Deming, Daniel C. Anderson, Ezra Wood, Hariprasad D. Alwe, Dylan B. Millet, Andrew Weinheimer, Geoff Tyndall, John Ortega, Sebastien Dusanter, Thierry Leonardis, James Flynn, Matt Erickson, Sergio Alvarez, Jean C. Rivera-Rios, Joshua D. Shutter, Frank Keutsch, Detlev Helmig, Wei Wang, Hannah M. Allen, Johnathan H. Slade, Paul B. Shepson, Steven Bertman, and Philip S. Stevens
Atmos. Chem. Phys., 23, 10287–10311, https://doi.org/10.5194/acp-23-10287-2023, https://doi.org/10.5194/acp-23-10287-2023, 2023
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The hydroxyl (OH), hydroperoxy (HO2), and organic peroxy (RO2) radicals play important roles in atmospheric chemistry and have significant air quality implications. Here, we compare measurements of OH, HO2, and total peroxy radicals (XO2) made in a remote forest in Michigan, USA, to predictions from a series of chemical models. Lower measured radical concentrations suggest that the models may be missing an important radical sink and overestimating the rate of ozone production in this forest.
Vanessa Selimovic, Damien Ketcherside, Sreelekha Chaliyakunnel, Catherine Wielgasz, Wade Permar, Hélène Angot, Dylan B. Millet, Alan Fried, Detlev Helmig, and Lu Hu
Atmos. Chem. Phys., 22, 14037–14058, https://doi.org/10.5194/acp-22-14037-2022, https://doi.org/10.5194/acp-22-14037-2022, 2022
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Arctic warming has led to an increase in plants that emit gases in response to stress, but how these gases affect regional chemistry is largely unknown due to lack of observational data. Here we present the most comprehensive gas-phase measurements for this area to date and compare them to predictions from a global transport model. We report 78 gas-phase species and investigate their importance to atmospheric chemistry in the area, with broader implications for similar plant types.
Detlev Helmig, Alex Guenther, Jacques Hueber, Ryan Daly, Wei Wang, Jeong-Hoo Park, Anssi Liikanen, and Arnaud P. Praplan
Atmos. Meas. Tech., 15, 5439–5454, https://doi.org/10.5194/amt-15-5439-2022, https://doi.org/10.5194/amt-15-5439-2022, 2022
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This research demonstrates a new method for determination of the chemical reactivity of volatile organic compounds that are emitted from the leaves and needles of trees. These measurements allow elucidating if and how much of these emissions and their associated reactivity are captured and quantified by currently applicable chemical analysis methods.
Albane Barbero, Roberto Grilli, Markus M. Frey, Camille Blouzon, Detlev Helmig, Nicolas Caillon, and Joël Savarino
Atmos. Chem. Phys., 22, 12025–12054, https://doi.org/10.5194/acp-22-12025-2022, https://doi.org/10.5194/acp-22-12025-2022, 2022
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The high reactivity of the summer Antarctic boundary layer results in part from the emissions of nitrogen oxides produced during photo-denitrification of the snowpack, but its underlying mechanisms are not yet fully understood. The results of this study suggest that more NO2 is produced from the snowpack early in the photolytic season, possibly due to stronger UV irradiance caused by a smaller solar zenith angle near the solstice.
Elisabeth Mauclet, Yannick Agnan, Catherine Hirst, Arthur Monhonval, Benoît Pereira, Aubry Vandeuren, Maëlle Villani, Justin Ledman, Meghan Taylor, Briana L. Jasinski, Edward A. G. Schuur, and Sophie Opfergelt
Biogeosciences, 19, 2333–2351, https://doi.org/10.5194/bg-19-2333-2022, https://doi.org/10.5194/bg-19-2333-2022, 2022
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Arctic warming and permafrost degradation largely affect tundra vegetation. Wetter lowlands show an increase in sedges, whereas drier uplands favor shrub expansion. Here, we demonstrate that the difference in the foliar elemental composition of typical tundra vegetation species controls the change in local foliar elemental stock and potential mineral element cycling through litter production upon a shift in tundra vegetation.
Hélène Angot, Connor Davel, Christine Wiedinmyer, Gabrielle Pétron, Jashan Chopra, Jacques Hueber, Brendan Blanchard, Ilann Bourgeois, Isaac Vimont, Stephen A. Montzka, Ben R. Miller, James W. Elkins, and Detlev Helmig
Atmos. Chem. Phys., 21, 15153–15170, https://doi.org/10.5194/acp-21-15153-2021, https://doi.org/10.5194/acp-21-15153-2021, 2021
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After a multidecadal global decline in atmospheric abundance of ethane and propane (precursors of tropospheric ozone and aerosols), previous work showed a reversal of this trend in 2009–2015 in the Northern Hemisphere due to the growth in oil and natural gas production in North America. Here we show a temporary pause in the growth of atmospheric ethane and propane in 2015–2018 and highlight the critical need for additional top-down studies to further constrain ethane and propane emissions.
Cited articles
Alaska Division of Oil and Gas: Regional geology of the north slope of
Alaska, 1 ∕ 1 000 000, State of Alaska, Department of Natural
Resources, Division of Oil and Gas, Anchorage, 2008.
Angot, H., Dastoor, A., De Simone, F., Gårdfeldt, K., Gencarelli, C. N.,
Hedgecock, I. M., Langer, S., Magand, O., Mastromonaco, M. N., Nordstrøm,
C., Pfaffhuber, K. A., Pirrone, N., Ryjkov, A., Selin, N. E., Skov, H., Song,
S., Sprovieri, F., Steffen, A., Toyota, K., Travnikov, O., Yang, X., and
Dommergue, A.: Chemical cycling and deposition of atmospheric mercury in
polar regions: review of recent measurements and comparison with models,
Atmos. Chem. Phys., 16, 10735–10763,
https://doi.org/10.5194/acp-16-10735-2016, 2016a.
Angot, H., Magand, O., Helmig, D., Ricaud, P., Quennehen, B., Gallée, H.,
Del Guasta, M., Sprovieri, F., Pirrone, N., Savarino, J., and Dommergue, A.:
New insights into the atmospheric mercury cycling in central Antarctica and
implications on a continental scale, Atmos. Chem. Phys., 16, 8249–8264,
https://doi.org/10.5194/acp-16-8249-2016, 2016b.
Atwell, L., Hobson, K. A., and Welch, H. E.: Biomagnification and
bioaccumulation of mercury in an arctic marine food web: insights from stable
nitrogen isotope analysis, Can. J. Fish. Aquat. Sci., 55, 1114–1121,
https://doi.org/10.1139/f98-001, 1998.
Barker, A. J., Douglas, T. A., Jacobson, A. D., McClelland, J. W., Ilgen, A.
G., Khosh, M. S., Lehn, G. O., and Trainor, T. P.: Late season mobilization
of trace metals in two small Alaskan arctic watersheds as a proxy for
landscape scale permafrost active layer dynamics, Chem. Geol., 381, 180–193,
https://doi.org/10.1016/j.chemgeo.2014.05.012, 2014.
Bergin, M. H., Jaffrezo, J.-L., Davidson, C. I., Dibb, J. E., Pandis, S. N.,
Hillamo, R., Maenhaut, W., Kuhns, H. D., and Makela, T.: The contributions of
snow, fog, and dry deposition to the summer flux of anions and cations at
Summit, Greenland, J. Geophys. Res.-Atmos., 100, 16275–16288,
https://doi.org/10.1029/95JD01267, 1995.
Brooks, S., Lindberg, S., Southworth, G., and Arimoto, R.: Springtime
atmospheric mercury speciation in the McMurdo, Antarctica coastal region,
Atmos. Environ., 42, 2885–2893, https://doi.org/10.1016/j.atmosenv.2007.06.038, 2008.
Brooks, S. B., Saiz-Lopez, A., Skov, H., Lindberg, S. E., Plane, J. M. C.,
and Goodsite, M. E.: The mass balance of mercury in the springtime arctic
environment, Geophys. Res. Lett., 33, L13812, https://doi.org/10.1029/2005GL025525, 2006.
de Caritat, P., Hall, G., Gìslason, S., Belsey, W., Braun, M.,
Goloubeva, N. I., Olsen, H. K., Scheie, J. O., and Vaive, J. E.: Chemical
composition of arctic snow: concentration levels and regional distribution of
major elements, Sci. Total Environ., 336, 183–199,
https://doi.org/10.1016/j.scitotenv.2004.05.031, 2005.
Cherry, J. E., Déry, S. J., Cheng, Y., Stieglitz, M., Jacobs, A. S., and
Pan, F.: Climate and hydrometeorology of the Toolik Lake region and the
Kuparuk River basin, in: Alaska's changing arctic: ecological consequences
for tundra, streams, and lakes, edited by: Hobbie, J. E. and Kling, G. W.,
21–60, Oxford University Press, New York, 2014.
Cobbett, F. D., Steffen, A., Lawson, G., and van Heyst, B. J.: GEM fluxes and
atmospheric mercury concentrations (GEM, RGM and Hgp) in the Canadian Arctic
at Alert, Nunavut, Canada (February–June 2005), Atmos. Environ., 41,
6527–6543, https://doi.org/10.1016/j.atmosenv.2007.04.033, 2007.
Corbitt, E. S., Jacob, D. J., Holmes, C. D., Streets, D. G., and Sunderland,
E. M.: Global source-receptor relationships for mercury deposition under
present-day and 2050 emissions scenarios, Environ. Sci. Technol., 45,
10477–10484, https://doi.org/10.1021/es202496y, 2011.
Craig, H.: Isotopic variations in meteoric waters, Science, 133, 1702–1703,
https://doi.org/10.1126/science.133.3465.1702, 1961.
Dominé, F. and Shepson, P. B.: Air-snow interactions and atmospheric
chemistry, Science, 297, 1506–1510, https://doi.org/10.1126/science.1074610, 2002.
Dommergue, A., Ferrari, C. P., Poissant, L., Gauchard, P.-A., and Boutron, C.
F.: Diurnal cycles of gaseous mercury within the snowpack at
Kuujjuarapik/Whapmagoostui, Québec, Canada, Environ. Sci. Technol., 37,
3289–3297, https://doi.org/10.1021/es026242b, 2003.
Dommergue, A., Sprovieri, F., Pirrone, N., Ebinghaus, R., Brooks, S.,
Courteaud, J., and Ferrari, C. P.: Overview of mercury measurements in the
Antarctic troposphere, Atmos. Chem. Phys., 10, 3309–3319,
https://doi.org/10.5194/acp-10-3309-2010, 2010.
Douglas, T. A. and Sturm, M.: Arctic haze, mercury and the chemical
composition of snow across northwestern Alaska, Atmos. Environ., 38,
805–820, https://doi.org/10.1016/j.atmosenv.2003.10.042, 2004.
Douglas, T. A., Sturm, M., Simpson, W. R., Brooks, S., Lindberg, S. E., and
Perovich, D. K.: Elevated mercury measured in snow and frost flowers near
Arctic sea ice leads, Geophys. Res. Lett., 32, L04502,
https://doi.org/10.1029/2004GL022132, 2005.
Douglas, T. A., Sturm, M., Simpson, W. R., Blum, J. D., Alvarez-Aviles, L.,
Keeler, G. J., Perovich, D. K., Biswas, A., and Johnson, K.: Influence of
snow and ice crystal formation and accumulation on mercury deposition to the
Arctic, Environ. Sci. Technol., 42, 1542–1551, https://doi.org/10.1021/es070502d, 2008.
Douglas, T. A., Loseto, L. L., Macdonald, R. W., Outridge, P., Dommergue, A.,
Poulain, A., Amyot, M., Barkay, T., Berg, T., Chételat, J., Constant, P.,
Evans, M., Ferrari, C., Gantner, N., Johnson, M. S., Kirk, J., Kroer, N.,
Larose, C., Lean, D., Nielsen, T. G., Poissant, L., Rognerud, S., Skov, H.,
Sørensen, S., Wang, F., Wilson, S., and Zdanowicz, C. M.: The fate of
mercury in arctic terrestrial and aquatic ecosystems, a review, Environ.
Chem., 9, 321–355, https://doi.org/10.1071/EN11140, 2012.
Douglas, T. A., Sturm, M., Blum, J. D., Polashenski, C., Stuefer, S.,
Hiemstra, C., Steffen, A., Filhol, S., and Prevost, R.: A pulse of mercury
and major ions in snowmelt runoff from a small arctic Alaska watershed,
Environ. Sci. Technol., 51, 11145–11155, https://doi.org/10.1021/acs.est.7b03683, 2017.
Driscoll, C. T., Mason, R. P., Chan, H. M., Jacob, D. J., and Pirrone, N.:
Mercury as a global pollutant: sources, pathways, and effects, Environ. Sci.
Technol., 47, 4967–4983, https://doi.org/10.1021/es305071v, 2013.
Enrico, M., Le Roux, G., Heimbürger, L.-E., Van Beek, P., Souhaut, M.,
Chmeleff, J., and Sonke, J. E.: Holocene atmospheric mercury levels
reconstructed from peat bog mercury stable isotopes, Environ. Sci. Technol.,
51, 5899–5906, https://doi.org/10.1021/acs.est.6b05804, 2017.
Essery, R. and Pomeroy, J.: Vegetation and topographic control of wind-blown
snow distributions in distributed and aggregated simulations for an arctic
tundra basin, J. Hydrometeorol., 5, 735–744,
https://doi.org/10.1175/1525-7541(2004)005<0735:VATCOW>2.0.CO;2, 2004.
Essery, R., Li, L., and Pomeroy, J.: A distributed model of blowing snow over
complex terrain, Hydrol. Process., 13, 2423–2438,
https://doi.org/10.1002/(SICI)1099-1085(199910)13:14/15<2423::AID-HYP853>3.0.CO;2-U,
1999.
Faïn, X., Grangeon, S., Bahlmann, E., Fritsche, J., Obrist, D.,
Dommergue, A., Ferrari, C. P., Cairns, W., Ebinghaus, R., Barbante, C.,
Cescon, P., and Boutron, C.: Diurnal production of gaseous mercury in the
alpine snowpack before snowmelt, J. Geophys. Res., 112, D21311,
https://doi.org/10.1029/2007JD008520, 2007.
Faïn, X., Ferrari, C. P., Dommergue, A., Albert, M., Battle, M., Arnaud,
L., Barnola, J.-M., Cairns, W., Barbante, C., and Boutron, C.: Mercury in the
snow and firn at Summit Station, Central Greenland, and implications for the
study of past atmospheric mercury levels, Atmos. Chem. Phys., 8, 3441–3457,
https://doi.org/10.5194/acp-8-3441-2008, 2008.
Faïn, X., Obrist, D., Pierce, A., Barth, C., Gustin, M. S., and Boyle, D.
P.: Whole-watershed mercury balance at Sagehen Creek, Sierra Nevada, CA,
Geochim. Cosmochim. Acta, 75, 2379–2392, https://doi.org/10.1016/j.gca.2011.01.041,
2011.
Faïn, X., Helmig, D., Hueber, J., Obrist, D., and Williams, M. W.:
Mercury dynamics in the Rocky Mountain, Colorado, snowpack, Biogeosciences,
10, 3793–3807, https://doi.org/10.5194/bg-10-3793-2013, 2013.
Ferrari, C. P., Dommergue, A., Boutron, C. F., Jitaru, P., and Adams, F. C.:
Profiles of mercury in the snow pack at Station Nord, Greenland shortly after
polar sunrise, Geophys. Res. Lett., 31, L03401, https://doi.org/10.1029/2003GL018961,
2004.
Ferrari, C. P., Gauchard, P.-A., Aspmo, K., Dommergue, A., Magand, O.,
Bahlmann, E., Nagorski, S., Temme, C., Ebinghaus, R., Steffen, A., Banic, C.,
Berg, T., Planchon, F., Barbante, C., Cescon, P., and Boutron, C. F.:
Snow-to-air exchanges of mercury in an Arctic seasonal snow pack in
Ny-Ålesund, Svalbard, Atmos. Environ., 39, 7633–7645,
https://doi.org/10.1016/j.atmosenv.2005.06.058, 2005.
Ferrari, C. P., Padova, C., Faïn, X., Gauchard, P.-A., Dommergue, A.,
Aspmo, K., Berg, T., Cairns, W., Barbante, C., Cescon, P., Kaleschke, L.,
Richter, A., Wittrock, F., and Boutron, C.: Atmospheric mercury depletion
event study in Ny-Ålesund (Svalbard) in spring 2005, Deposition and
transformation of Hg in surface snow during springtime, Sci. Total Environ.,
397, 167–177, https://doi.org/10.1016/j.scitotenv.2008.01.064, 2008.
Fitzgerald, W. F., Engstrom, D. R., Lamborg, C. H., Tseng, C.-M., Balcom, P.
H., and Hammerschmidt, C. R.: Modern and historic atmospheric mercury fluxes
in Northern Alaska: global sources and arctic depletion, Environ. Sci.
Technol., 39, 557–568, https://doi.org/10.1021/es049128x, 2005.
Fitzgerald, W. F., Hammerschmidt, C. R., Engstrom, D. R., Balcom, P. H.,
Lamborg, C. H., and Tseng, C.-M.: Mercury in the Alaskan arctic, in Alaska's
changing arctic: ecological consequences for tundra, streams, and lakes,
edited by: Hobbie, J. E. and Kling, G. W., Oxford University Press, New York,
287–302, 2014.
Garbarino, J. R., Snyder-Conn, E., Leiker, T. J., and Hoffman, G. L.:
Contaminants in Arctic snow collected over Northwest Alaskan sea ice, Water.
Air. Soil Pollut., 139, 183–214, https://doi.org/10.1023/A:1015808008298, 2002.
Gat, J. R.: Isotope hydrology: a study of the water cycle, World Scientific,
London, 2010.
King, M. D. and Simpson, W. R.: Extinction of UV radiation in arctic snow at
Alert, Canada (82∘ N), J. Geophys. Res.-Atmos., 106, 12499–12507,
https://doi.org/10.1029/2001JD900006, 2001.
Kirk, J. L., St. Louis, V. L., and Sharp, M. J.: Rapid reduction and
reemission of mercury deposited into snowpacks during atmospheric mercury
depletion events at Churchill, Manitoba, Canada, Environ. Sci. Technol., 40,
7590–7596, https://doi.org/10.1021/es061299+, 2006.
Krnavek, L., Simpson, W. R., Carlson, D., Domine, F., Douglas, T. A., and
Sturm, M.: The chemical composition of surface snow in the Arctic: Examining
marine, terrestrial, and atmospheric influences, Atmos. Environ., 50,
349–359, https://doi.org/10.1016/j.atmosenv.2011.11.033, 2012.
Lalonde, J. D., Poulain, A. J., and Amyot, M.: The role of mercury redox
reactions in snow on snow-to-air mercury transfer, Environ. Sci. Technol.,
36, 174–178, https://doi.org/10.1021/es010786g, 2002.
Landers, D. H., Ford, J., Gubala, C., Monetti, M., Lasorsa, B. K., and
Martinson, J.: Mercury in vegetation and lake sediments from the U.S. Arctic,
Water Air. Soil Pollut., 80, 591–601, https://doi.org/10.1007/BF01189711, 1995.
Lindberg, S. E., Hanson, P. J., Meyers, T. P., and Kim, K.-H.: Air/surface
exchange of mercury vapor over forests – the need for a reassessment of
continental biogenic emissions, Atmos. Environ., 32, 895–908,
https://doi.org/10.1016/S1352-2310(97)00173-8, 1998.
Liptzin, D., Williams, M. W., Helmig, D., Seok, B., Filippa, G., Chowanski,
K., and Hueber, J.: Process-level controls on CO2 fluxes from a seasonally
snow-covered subalpine meadow soil, Niwot Ridge, Colorado, Biogeochemistry,
95, 151–166, https://doi.org/10.1007/s10533-009-9303-2, 2009.
Mann, E., Meyer, T., Mitchell, C. P. J., and Wania, F.: Mercury fate in
ageing and melting snow: development and testing of a controlled laboratory
system, J. Environ. Monit., 13, 2695–2702, https://doi.org/10.1039/C1EM10297D, 2011.
Mann, E., Ziegler, S., Mallory, M., and O'Driscoll, N.: Mercury
photochemistry in snow and implications for arctic ecosystems, Environ. Rev.,
22, 331–345, https://doi.org/10.1139/er-2014-0006, 2014.
Mann, E. A., Mallory, M. L., Ziegler, S. E., Tordon, R., and O'Driscoll, N.
J.: Mercury in Arctic snow: quantifying the kinetics of photochemical
oxidation and reduction, Sci. Total Environ., 509–510, 115–132,
https://doi.org/10.1016/j.scitotenv.2014.07.056, 2015.
Monson, R. K., Burns, S. P., Williams, M. W., Delany, A. C., Weintraub, M.,
and Lipson, D. A.: The contribution of beneath-snow soil respiration to total
ecosystem respiration in a high-elevation, subalpine forest, Global
Biogeochem. Cy., 20, GB3030, https://doi.org/10.1029/2005GB002684, 2006.
Moore, C. W., Obrist, D., Steffen, A., Staebler, R. M., Douglas, T. A.,
Richter, A., and Nghiem, S. V.: Convective forcing of mercury and ozone in
the Arctic boundary layer induced by leads in sea ice, Nature, 506, 81–84,
https://doi.org/10.1038/nature12924, 2014.
National Atmospheric Deposition Program: NRSP-3, NADP Program Office,
Illinois State Water Survey, University of Illinois, Champaign, IL 61820.,
2017.
Nerentorp Mastromonaco, M., Gårdfeldt, K., Jourdain, B., Abrahamsson, K.,
Granfors, A., Ahnoff, M., Dommergue, A., Méjean, G., and Jacobi, H.-W.:
Antarctic winter mercury and ozone depletion events over sea ice, Atmos.
Environ., 129, 125–132, https://doi.org/10.1016/j.atmosenv.2016.01.023, 2016.
Norman, A. L., Barrie, L. A., Toom-Sauntry, D., Sirois, A., Krouse, H. R.,
Li, S. M., and Sharma, S.: Sources of aerosol sulphate at Alert:
apportionment using stable isotopes, J. Geophys. Res.-Atmos., 104,
11619–11631, https://doi.org/10.1029/1999JD900078, 1999.
Obrist, D., Tas, E., Peleg, M., Matveev, V., Faïn, X., Asaf, D., and
Luria, M.: Bromine-induced oxidation of mercury in the mid-latitude
atmosphere, Nat. Geosci., 4, 22–26, https://doi.org/10.1038/ngeo1018, 2011.
Obrist, D., Pokharel, A. K., and Moore, C.: Vertical profile measurements of
soil air suggest immobilization of gaseous elemental mercury in mineral soil,
Environ. Sci. Technol., 48, 2242–2252, https://doi.org/10.1021/es4048297, 2014.
Obrist, D., Agnan, Y., Jiskra, M., Olson, C. L., Colegrove, D. P., Hueber,
J., Moore, C. W., Sonke, J. E., and Helmig, D.: Tundra uptake of atmospheric
elemental mercury drives Arctic mercury pollution, Nature, 547, 201–204,
https://doi.org/10.1038/nature22997, 2017.
Oechel, W. C., Vourlitis, G., and Hastings, S. J.: Cold season CO2
emission from arctic soils, Global Biogeochem. Cy., 11, 163–172,
https://doi.org/10.1029/96GB03035, 1997.
Pearson, C., Schumer, R., Trustman, B. D., Rittger, K., Johnson, D. W., and
Obrist, D.: Nutrient and mercury deposition and storage in an alpine snowpack
of the Sierra Nevada, USA, Biogeosciences, 12, 3665–3680,
https://doi.org/10.5194/bg-12-3665-2015, 2015.
Poulain, A. J., Lalonde, J. D., Amyot, M., Shead, J. A., Raofie, F., and
Ariya, P. A.: Redox transformations of mercury in an Arctic snowpack at
springtime, Atmos. Environ., 38, 6763–6774,
https://doi.org/10.1016/j.atmosenv.2004.09.013, 2004.
Schroeder, W. H. and Munthe, J.: Atmospheric mercury – An overview, Atmos.
Environ., 32, 809–822, https://doi.org/10.1016/S1352-2310(97)00293-8, 1998.
Schroeder, W. H., Anlauf, K. G., Barrie, L. A., Lu, J. Y., Steffen, A.,
Schneeberger, D. R., and Berg, T.: Arctic springtime depletion of mercury,
Nature, 394, 331–332, https://doi.org/10.1038/28530, 1998.
Selin, N. E.: Global biogeochemical cycling of mercury: a review, Annu. Rev.
Environ. Resour., 34, 43–63, https://doi.org/10.1146/annurev.environ.051308.084314,
2009.
Seok, B., Helmig, D., Williams, M. W., Liptzin, D., Chowanski, K., and
Hueber, J.: An automated system for continuous measurements of trace gas
fluxes through snow: an evaluation of the gas diffusion method at a subalpine
forest site, Niwot Ridge, Colorado, Biogeochemistry, 95, 95–113,
https://doi.org/10.1007/s10533-009-9302-3, 2009.
Shaver, G. R. and Chapin, F. S.: Production: biomass relationships and
element cycling in contrasting arctic vegetation types, Ecol. Monogr., 61,
1–31, https://doi.org/10.2307/1942997, 1991.
Siegenthaler, U. and Oeschger, H.: Correlation of 18O in
precipitation with temperature and altitude, Nature, 285, 314–317,
https://doi.org/10.1038/285314a0, 1980.
Simpson, W. R., von Glasow, R., Riedel, K., Anderson, P., Ariya, P.,
Bottenheim, J., Burrows, J., Carpenter, L. J., Frieß, U., Goodsite, M.
E., Heard, D., Hutterli, M., Jacobi, H.-W., Kaleschke, L., Neff, B., Plane,
J., Platt, U., Richter, A., Roscoe, H., Sander, R., Shepson, P., Sodeau, J.,
Steffen, A., Wagner, T., and Wolff, E.: Halogens and their role in polar
boundary-layer ozone depletion, Atmos. Chem. Phys., 7, 4375–4418,
https://doi.org/10.5194/acp-7-4375-2007, 2007.
Snyder-Conn, E., Garbarino, J. R., Hoffman, G. L., and Oelkers, A.: Soluble
trace elements and total mercury in arctic alaskan snow, Arctic, 50,
201–215, 1997.
Sprovieri, F., Pirrone, N., Ebinghaus, R., Kock, H., and Dommergue, A.: A
review of worldwide atmospheric mercury measurements, Atmos. Chem. Phys., 10,
8245–8265, https://doi.org/10.5194/acp-10-8245-2010, 2010.
St. Louis, V. L., Sharp, M. J., Steffen, A., May, A., Barker, J., Kirk, J.
L., Kelly, D. J. A., Arnott, S. E., Keatley, B., and Smol, J. P.: Some
sources and sinks of monomethyl and inorganic mercury on Ellesmere Island in
the Canadian high Arctic, Environ. Sci. Technol., 39, 2686–2701,
https://doi.org/10.1021/es049326o, 2005.
Steffen, A., Schroeder, W., Bottenheim, J., Narayan, J., and Fuentes, J. D.:
Atmospheric mercury concentrations: measurements and profiles near snow and
ice surfaces in the Canadian Arctic during Alert 2000, Atmos. Environ., 36,
2653–2661, https://doi.org/10.1016/S1352-2310(02)00112-7, 2002.
Steffen, A., Douglas, T., Amyot, M., Ariya, P., Aspmo, K., Berg, T.,
Bottenheim, J., Brooks, S., Cobbett, F., Dastoor, A., Dommergue, A.,
Ebinghaus, R., Ferrari, C., Gardfeldt, K., Goodsite, M. E., Lean, D.,
Poulain, A. J., Scherz, C., Skov, H., Sommar, J., and Temme, C.: A synthesis
of atmospheric mercury depletion event chemistry in the atmosphere and snow,
Atmos. Chem. Phys., 8, 1445–1482, https://doi.org/10.5194/acp-8-1445-2008, 2008.
Steffen, A., Bottenheim, J., Cole, A., Douglas, T. A., Ebinghaus, R., Friess,
U., Netcheva, S., Nghiem, S., Sihler, H., and Staebler, R.: Atmospheric
mercury over sea ice during the OASIS-2009 campaign, Atmos. Chem. Phys., 13,
7007–7021, https://doi.org/10.5194/acp-13-7007-2013, 2013.
Steffen, A., Bottenheim, J., Cole, A., Ebinghaus, R., Lawson, G., and
Leaitch, W. R.: Atmospheric mercury speciation and mercury in snow over time
at Alert, Canada, Atmos. Chem. Phys., 14, 2219–2231,
https://doi.org/10.5194/acp-14-2219-2014, 2014.
Sturm, M. and Liston, G. E.: The snow cover on lakes of the Arctic Coastal
Plain of Alaska, USA, J. Glaciol., 49, 370–380,
https://doi.org/10.3189/172756503781830539, 2003.
Toom-Sauntry, D. and Barrie, L. A.: Chemical composition of snowfall in the
high Arctic: 1990–1994, Atmos. Environ., 36, 2683–2693,
https://doi.org/10.1016/S1352-2310(02)00115-2, 2002.
Uematsu, M., Kinoshita, K., and Nojiri, Y.: Scavenging of insoluble particles
from the marine atmosphere over the sub-arctic north Pacific, J. Atmos.
Chem., 35, 151–163, https://doi.org/10.1023/A:1006219028497, 2000.
US EPA: Method 1631: Mercury in water by oxidation, purge and trap, and cold
vapor atomic fluorescence spectrometry, United States Environmental
Protection Agency, 2002.
Van Dam, B., Helmig, D., Burkhart, J. F., Obrist, D., and Oltmans, S. J.:
Springtime boundary layer O3 and GEM depletion at Toolik Lake, Alaska, J.
Geophys. Res.-Atmos., 118, 3382–3391, https://doi.org/10.1002/jgrd.50213, 2013.
Short summary
In this study, we investigated mercury dynamics in an interior arctic tundra at Toolik Field Station (200 km from the Arctic Ocean) during two full snow seasons. We continuously measured atmospheric, snow gas phase, and soil pores mercury concentrations. We observed consistent concentration declines from the atmosphere to snowpack to soils, indicating that soils are continuous sinks of mercury. We suggest that interior arctic snowpacks may be negligible sources of mercury.
In this study, we investigated mercury dynamics in an interior arctic tundra at Toolik Field...