Dr. Helen M Amos

Dr. Helen M Amos

  • SR. RESEARCH SCIENTIST
  • 301.286.8417
  • NASA/GSFC
  • Mail Code: 610
  • Greenbelt , MD 20771
  • Employer: SCIENCE SYSTEMS AND APPLICATIONS INC
  • Brief Bio

    Dr. Helen Amos is an Earth System scientist interested in applications to public health. Dr. Amos joined the GLOBE Observer program in September 2018, where she coordinates outreach to the scientific research community. Prior to joining GLOBE Observer, Dr. Amos was a AAAS Science & Technology Policy fellow on the Innovation Team at the US Environmental Protection Agency in Washington, DC. Dr. Amos received her PhD in atmospheric chemistry  from Harvard University in 2014.  

    ORCiD 0000-0002-0297-6643.

    Publications

    Refereed

    Wagner, C. C., H. M. Amos, C. P. Thackray, et al. Y. Zhang, E. W. Lundgren, G. Forget, C. L. Friedman, N. E. Selin, R. Lohmann, and E. M. Sunderland. 2019. "A global 3-D ocean model for polychlorinated biphenyls (PCBs): Benchmark compounds for understanding the impacts of global change on neutral persistent organic pollutants." Global Biogeochemical Cycles, [10.1029/2018gb006018]

    Amos, H. M., C. F. Miniat, J. Lynch, et al. J. Compton, P. H. Templer, L. A. Sprague, D. Shaw, D. Burns, A. Rea, D. Whitall, L. Myles, D. Gay, M. Nilles, J. Walker, A. K. Rose, J. Bales, J. Deacon, and R. Pouyat. 2018. "What Goes Up Must Come Down: Integrating Air and Water Quality Monitoring for Nutrients." Environmental Science & Technology, 52 (20): 11441-11448 [10.1021/acs.est.8b03504]

    Sun, R., M. Jiskra, H. M. Amos, et al. Y. Zhang, E. M. Sunderland, and J. E. Sonke. 2018. "Modelling the mercury stable isotope distribution of Earth surface reservoirs: Implications for global Hg cycling." Geochimica et Cosmochimica Acta, (In Press) [10.1016/j.gca.2018.11.036]

    Kocman, D., S. Wilson, H. Amos, et al. K. Telmer, F. Steenhuisen, E. Sunderland, R. Mason, P. Outridge, and M. Horvat. 2017. "Toward an Assessment of the Global Inventory of Present-Day Mercury Releases to Freshwater Environments." International Journal of Environmental Research and Public Health, 14 (2): 138 [10.3390/ijerph14020138]

    Horowitz, H. M., D. J. Jacob, Y. Zhang, et al. T. S. Dibble, F. Slemr, H. M. Amos, J. A. Schmidt, E. S. Corbitt, E. A. Marais, and E. M. Sunderland. 2017. "A new mechanism for atmospheric mercury redox chemistry: implications for the global mercury budget." Atmospheric Chemistry and Physics, 17 (10): 6353-6371 [10.5194/acp-17-6353-2017]

    Zhang, Y., D. J. Jacob, H. M. Horowitz, et al. L. Chen, H. M. Amos, D. P. Krabbenhoft, F. Slemr, V. L. St. Louis, and E. M. Sunderland. 2016. "Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions." Proceedings of the National Academy of Sciences, 113 (3): 526-531 [10.1073/pnas.1516312113]

    Sun, R., D. G. Streets, H. M. Horowitz, et al. H. M. Amos, G. Liu, V. Perrot, J.-P. Toutain, H. Hintelmann, E. M. Sunderland, and J. E. Sonke. 2016. "Historical (1850–2010) mercury stable isotope inventory from anthropogenic sources to the atmosphere." Elementa: Science of the Anthropocene, 4: 000091 [10.12952/journal.elementa.000091]

    Weiss-Penzias, P., H. M. Amos, N. E. Selin, et al. M. S. Gustin, D. A. Jaffe, D. Obrist, G.-R. Sheu, and A. Giang. 2015. "Use of a global model to understand speciated atmospheric mercury observations at five high-elevation sites." Atmospheric Chemistry and Physics, 15 (3): 1161-1173 [10.5194/acp-15-1161-2015]

    Amos, H. M., J. E. Sonke, D. Obrist, et al. N. Robins, N. Hagan, H. M. Horowitz, R. P. Mason, M. Witt, I. M. Hedgecock, E. S. Corbitt, and E. M. Sunderland. 2015. "Observational and Modeling Constraints on Global Anthropogenic Enrichment of Mercury." Environmental Science & Technology, 49 (7): 4036-4047 [10.1021/es5058665]

    Gustin, M. S., H. M. Amos, J. Huang, M. B. Miller, and K. Heidecorn. 2015. "Measuring and modeling mercury in the atmosphere: a critical review." Atmospheric Chemistry and Physics, 15 (10): 5697-5713 [10.5194/acp-15-5697-2015]

    Zhang, Y., D. J. Jacob, S. Dutkiewicz, et al. H. M. Amos, M. S. Long, and E. M. Sunderland. 2015. "Biogeochemical drivers of the fate of riverine mercury discharged to the global and Arctic oceans." Global Biogeochemical Cycles, 29 (6): 854-864 [10.1002/2015gb005124]

    Sofen, E. D., B. Alexander, E. J. Steig, et al. M. H. Thiemens, S. A. Kunasek, H. M. Amos, A. J. Schauer, M. G. Hastings, J. Bautista, T. L. Jackson, L. E. Vogel, J. R. McConnell, D. R. Pasteris, and E. S. Saltzman. 2014. "WAIS Divide ice core suggests sustained changes in the atmospheric formation pathways of sulfate and nitrate since the 19th century in the extratropical Southern Hemisphere." Atmospheric Chemistry and Physics, 14 (11): 5749-5769 [10.5194/acp-14-5749-2014]

    Jaffe, D. A., S. Lyman, H. M. Amos, et al. M. S. Gustin, J. Huang, N. E. Selin, L. Levin, A. ter Schure, R. P. Mason, R. Talbot, A. Rutter, B. Finley, L. Jaeglé, V. Shah, C. McClure, J. Ambrose, L. Gratz, S. Lindberg, P. Weiss-Penzias, G.-R. Sheu, D. Feddersen, M. Horvat, A. Dastoor, A. J. Hynes, H. Mao, J. E. Sonke, F. Slemr, J. A. Fisher, R. Ebinghaus, Y. Zhang, and G. Edwards. 2014. "Progress on Understanding Atmospheric Mercury Hampered by Uncertain Measurements." Environmental Science & Technology, 48 (13): 7204-7206 [10.1021/es5026432]

    Amos, H. M., D. J. Jacob, D. Kocman, et al. H. M. Horowitz, Y. Zhang, S. Dutkiewicz, M. Horvat, E. S. Corbitt, D. P. Krabbenhoft, and E. M. Sunderland. 2014. "Global Biogeochemical Implications of Mercury Discharges from Rivers and Sediment Burial." Environmental Science & Technology, 48 (16): 9514-9522 [10.1021/es502134t]

    Horowitz, H. M., D. J. Jacob, H. M. Amos, D. G. Streets, and E. M. Sunderland. 2014. "Historical Mercury Releases from Commercial Products: Global Environmental Implications." Environmental Science & Technology, 48 (17): 10242-10250 [10.1021/es501337j]

    Amos, H. M., D. J. Jacob, D. G. Streets, and E. M. Sunderland. 2013. "Legacy impacts of all-time anthropogenic emissions on the global mercury cycle." Global Biogeochemical Cycles, 27 (2): 410-421 [10.1002/gbc.20040]

    Fisher, J. A., D. J. Jacob, A. L. Soerensen, et al. H. M. Amos, E. S. Corbitt, D. G. Streets, Q. Wang, R. M. Yantosca, and E. M. Sunderland. 2013. "Factors driving mercury variability in the Arctic atmosphere and ocean over the past 30 years." Global Biogeochemical Cycles, 27 (4): 1226-1235 [10.1002/2013gb004689]

    Amos, H. M., D. J. Jacob, C. D. Holmes, et al. J. A. Fisher, Q. Wang, R. M. Yantosca, E. S. Corbitt, E. Galarneau, A. P. Rutter, M. S. Gustin, A. Steffen, J. J. Schauer, J. A. Graydon, V. L. Louis, R. W. Talbot, E. S. Edgerton, Y. Zhang, and E. M. Sunderland. 2012. "Gas-particle partitioning of atmospheric Hg(II) and its effect on global mercury deposition." Atmospheric Chemistry and Physics, 12 (1): 591-603 [10.5194/acp-12-591-2012]

    Alexander, B., D. J. Allman, H. M. Amos, et al. T. D. Fairlie, J. Dachs, D. A. Hegg, and R. S. Sletten. 2012. "Isotopic constraints on the formation pathways of sulfate aerosol in the marine boundary layer of the subtropical northeast Atlantic Ocean." Journal of Geophysical Research: Atmospheres, 117 (D6): [10.1029/2011jd016773]

    Fisher, J. A., D. J. Jacob, A. L. Soerensen, et al. H. M. Amos, A. Steffen, and E. M. Sunderland. 2012. "Riverine source of Arctic Ocean mercury inferred from atmospheric observations." Nature Geoscience, 5 (7): 499-504 [10.1038/ngeo1478]

    Zhang, Y., L. Jaeglé, A. van Donkelaar, et al. R. V. Martin, C. D. Holmes, H. M. Amos, Q. Wang, R. Talbot, R. Artz, S. Brooks, W. Luke, T. M. Holsen, D. Felton, E. K. Miller, K. D. Perry, D. Schmeltz, A. Steffen, R. Tordon, P. Weiss-Penzias, and R. Zsolway. 2012. "Nested-grid simulation of mercury over North America." Atmospheric Chemistry and Physics, 12 (14): 6095-6111 [10.5194/acp-12-6095-2012]

    Schauer, A. J., S. A. Kunasek, E. D. Sofen, et al. J. Erbland, J. Savarino, B. W. Johnson, H. M. Amos, R. Shaheen, M. Abaunza, T. L. Jackson, M. H. Thiemens, and B. Alexander. 2012. "Oxygen isotope exchange with quartz during pyrolysis of silver sulfate and silver nitrate." Rapid Communications in Mass Spectrometry, 26 (18): 2151-2157 [10.1002/rcm.6332]

    Kunasek, S. A., B. Alexander, E. J. Steig, et al. E. D. Sofen, T. L. Jackson, M. H. Thiemens, J. R. McConnell, D. J. Gleason, and H. M. Amos. 2010. "Sulfate sources and oxidation chemistry over the past 230 years from sulfur and oxygen isotopes of sulfate in a West Antarctic ice core." Journal of Geophysical Research, 115 (D18): D18313 [10.1029/2010jd013846]

    Non-Refereed

    Walker, J. T., G. M. Beachley, H. M. Amos, et al. J. S. Baron, J. Bash, R. Baumgardner, M. D. Bell, K. B. Benedict, X. Chen, D. W. Clow, A. Cole, J. G. Coughlin, K. Cruz, R. W. Daly, S. M. Decina, E. M. Elliot, M. E. Fenn, L. Ganzeveld, K. Gebhart, S. S. Isil, B. M. Kerschner, R. S. Larson, T. Lavery, G. G. Lear, T. Macy, M. A. Mast, K. Mishoe, K. H. Morris, P. E. Padgett, R. V. Pouyat, M. Puchalski, H. O. Pye, A. W. Rea, M. F. Rhodes, C. M. Rogers, R. Saylor, R. Scheffe, B. A. Schichtel, D. B. Schwede, G. A. Sexstone, B. C. Sive, P. H. Templer, T. Thompson, D. Tong, G. A. Wetherbee, T. H. Whitlow, Z. Wu, Z. Yu, and L. Zhang. 2019. "Science needs for continued development of total nitrogen deposition budgets in the United States." U.S. Environmental Protection Agency, Washington, DC EPA 601/R-19/001: 391 [Full Text (Link)]

    Education

    Harvard University, Department of Earth & Planetary Sciences, PhD, 2009-2014.

    University of Washington, Department of Atmospheric Sciences, BS, 2005-2009. 

    Positions/Employment

    9/2018 - Present

    Senior Research Scientist

    SSAI, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
    9/2016 - 8/2018

    AAAS Science & Technology Policy Fellow

    US Environmental Protection Agency, Washington, DC, USA
    2/2016 - 8/2016

    Research Scientist

    Amos Environmental, LLC, Washington, DC, USA
    6/2014 - 1/2016

    Postdoctoral Fellow

    Harvard University, TH Chan School of Public Health, Cambridge, Massachusetts, USA

    Awards

    National Science Foundation Graduate Research Fellowship, 2011-2014

    American Meteorological Society Fellowship, sponsored by NASA’s Earth Science Division, 2009-2010

    Washington Scholar, 2005-2009

    Teaching Experience

    Teaching Fellow for Engineering Sciences 169: Seminar on Global Pollution Issues: Case Study of Mercury Biogeochemistry, Professor Elsie M. Sunderland, Spring Semester 2013

    Teaching Fellow for Earth & Planetary Sciences 200: Atmospheric Chemistry (Graduate Level), Harvard University, Professor Daniel J. Jacob, Fall Semester 2010

    Teaching Fellow for Engineering Sceinces 6: Intro to Environmental Science and Technology (Undergraduate Level), Harvard University, Professor Scot Martin, Spring Semester 2011

    Professional Societies

    American Association for the Advancement of Science, 2016 - Present
    American Geophysical Union, 2009 - Present
    Earth Science Women's Network, 2009 - Present

    Brief Bio

    Dr. Helen Amos is an Earth System scientist interested in applications to public health. Dr. Amos joined the GLOBE Observer program in September 2018, where she coordinates outreach to the scientific research community. Prior to joining GLOBE Observer, Dr. Amos was a AAAS Science & Technology Policy fellow on the Innovation Team at the US Environmental Protection Agency in Washington, DC. Dr. Amos received her PhD in atmospheric chemistry  from Harvard University in 2014.  

    ORCiD 0000-0002-0297-6643.

    Publications

    Refereed

    Wagner, C. C., H. M. Amos, C. P. Thackray, et al. Y. Zhang, E. W. Lundgren, G. Forget, C. L. Friedman, N. E. Selin, R. Lohmann, and E. M. Sunderland. 2019. "A global 3-D ocean model for polychlorinated biphenyls (PCBs): Benchmark compounds for understanding the impacts of global change on neutral persistent organic pollutants." Global Biogeochemical Cycles [10.1029/2018gb006018]

    Amos, H. M., C. F. Miniat, J. Lynch, et al. J. Compton, P. H. Templer, L. A. Sprague, D. Shaw, D. Burns, A. Rea, D. Whitall, L. Myles, D. Gay, M. Nilles, J. Walker, A. K. Rose, J. Bales, J. Deacon, and R. Pouyat. 2018. "What Goes Up Must Come Down: Integrating Air and Water Quality Monitoring for Nutrients." Environmental Science & Technology 52 (20): 11441-11448 [10.1021/acs.est.8b03504]

    Sun, R., M. Jiskra, H. M. Amos, et al. Y. Zhang, E. M. Sunderland, and J. E. Sonke. 2018. "Modelling the mercury stable isotope distribution of Earth surface reservoirs: Implications for global Hg cycling." Geochimica et Cosmochimica Acta (In Press) [10.1016/j.gca.2018.11.036]

    Kocman, D., S. Wilson, H. Amos, et al. K. Telmer, F. Steenhuisen, E. Sunderland, R. Mason, P. Outridge, and M. Horvat. 2017. "Toward an Assessment of the Global Inventory of Present-Day Mercury Releases to Freshwater Environments." International Journal of Environmental Research and Public Health 14 (2): 138 [10.3390/ijerph14020138]

    Horowitz, H. M., D. J. Jacob, Y. Zhang, et al. T. S. Dibble, F. Slemr, H. M. Amos, J. A. Schmidt, E. S. Corbitt, E. A. Marais, and E. M. Sunderland. 2017. "A new mechanism for atmospheric mercury redox chemistry: implications for the global mercury budget." Atmospheric Chemistry and Physics 17 (10): 6353-6371 [10.5194/acp-17-6353-2017]

    Zhang, Y., D. J. Jacob, H. M. Horowitz, et al. L. Chen, H. M. Amos, D. P. Krabbenhoft, F. Slemr, V. L. St. Louis, and E. M. Sunderland. 2016. "Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions." Proceedings of the National Academy of Sciences 113 (3): 526-531 [10.1073/pnas.1516312113]

    Sun, R., D. G. Streets, H. M. Horowitz, et al. H. M. Amos, G. Liu, V. Perrot, J.-P. Toutain, H. Hintelmann, E. M. Sunderland, and J. E. Sonke. 2016. "Historical (1850–2010) mercury stable isotope inventory from anthropogenic sources to the atmosphere." Elementa: Science of the Anthropocene 4 000091 [10.12952/journal.elementa.000091]

    Weiss-Penzias, P., H. M. Amos, N. E. Selin, et al. M. S. Gustin, D. A. Jaffe, D. Obrist, G.-R. Sheu, and A. Giang. 2015. "Use of a global model to understand speciated atmospheric mercury observations at five high-elevation sites." Atmospheric Chemistry and Physics 15 (3): 1161-1173 [10.5194/acp-15-1161-2015]

    Amos, H. M., J. E. Sonke, D. Obrist, et al. N. Robins, N. Hagan, H. M. Horowitz, R. P. Mason, M. Witt, I. M. Hedgecock, E. S. Corbitt, and E. M. Sunderland. 2015. "Observational and Modeling Constraints on Global Anthropogenic Enrichment of Mercury." Environmental Science & Technology 49 (7): 4036-4047 [10.1021/es5058665]

    Gustin, M. S., H. M. Amos, J. Huang, M. B. Miller, and K. Heidecorn. 2015. "Measuring and modeling mercury in the atmosphere: a critical review." Atmospheric Chemistry and Physics 15 (10): 5697-5713 [10.5194/acp-15-5697-2015]

    Zhang, Y., D. J. Jacob, S. Dutkiewicz, et al. H. M. Amos, M. S. Long, and E. M. Sunderland. 2015. "Biogeochemical drivers of the fate of riverine mercury discharged to the global and Arctic oceans." Global Biogeochemical Cycles 29 (6): 854-864 [10.1002/2015gb005124]

    Sofen, E. D., B. Alexander, E. J. Steig, et al. M. H. Thiemens, S. A. Kunasek, H. M. Amos, A. J. Schauer, M. G. Hastings, J. Bautista, T. L. Jackson, L. E. Vogel, J. R. McConnell, D. R. Pasteris, and E. S. Saltzman. 2014. "WAIS Divide ice core suggests sustained changes in the atmospheric formation pathways of sulfate and nitrate since the 19th century in the extratropical Southern Hemisphere." Atmospheric Chemistry and Physics 14 (11): 5749-5769 [10.5194/acp-14-5749-2014]

    Jaffe, D. A., S. Lyman, H. M. Amos, et al. M. S. Gustin, J. Huang, N. E. Selin, L. Levin, A. ter Schure, R. P. Mason, R. Talbot, A. Rutter, B. Finley, L. Jaeglé, V. Shah, C. McClure, J. Ambrose, L. Gratz, S. Lindberg, P. Weiss-Penzias, G.-R. Sheu, D. Feddersen, M. Horvat, A. Dastoor, A. J. Hynes, H. Mao, J. E. Sonke, F. Slemr, J. A. Fisher, R. Ebinghaus, Y. Zhang, and G. Edwards. 2014. "Progress on Understanding Atmospheric Mercury Hampered by Uncertain Measurements." Environmental Science & Technology 48 (13): 7204-7206 [10.1021/es5026432]

    Amos, H. M., D. J. Jacob, D. Kocman, et al. H. M. Horowitz, Y. Zhang, S. Dutkiewicz, M. Horvat, E. S. Corbitt, D. P. Krabbenhoft, and E. M. Sunderland. 2014. "Global Biogeochemical Implications of Mercury Discharges from Rivers and Sediment Burial." Environmental Science & Technology 48 (16): 9514-9522 [10.1021/es502134t]

    Horowitz, H. M., D. J. Jacob, H. M. Amos, D. G. Streets, and E. M. Sunderland. 2014. "Historical Mercury Releases from Commercial Products: Global Environmental Implications." Environmental Science & Technology 48 (17): 10242-10250 [10.1021/es501337j]

    Amos, H. M., D. J. Jacob, D. G. Streets, and E. M. Sunderland. 2013. "Legacy impacts of all-time anthropogenic emissions on the global mercury cycle." Global Biogeochemical Cycles 27 (2): 410-421 [10.1002/gbc.20040]

    Fisher, J. A., D. J. Jacob, A. L. Soerensen, et al. H. M. Amos, E. S. Corbitt, D. G. Streets, Q. Wang, R. M. Yantosca, and E. M. Sunderland. 2013. "Factors driving mercury variability in the Arctic atmosphere and ocean over the past 30 years." Global Biogeochemical Cycles 27 (4): 1226-1235 [10.1002/2013gb004689]

    Amos, H. M., D. J. Jacob, C. D. Holmes, et al. J. A. Fisher, Q. Wang, R. M. Yantosca, E. S. Corbitt, E. Galarneau, A. P. Rutter, M. S. Gustin, A. Steffen, J. J. Schauer, J. A. Graydon, V. L. Louis, R. W. Talbot, E. S. Edgerton, Y. Zhang, and E. M. Sunderland. 2012. "Gas-particle partitioning of atmospheric Hg(II) and its effect on global mercury deposition." Atmospheric Chemistry and Physics 12 (1): 591-603 [10.5194/acp-12-591-2012]

    Alexander, B., D. J. Allman, H. M. Amos, et al. T. D. Fairlie, J. Dachs, D. A. Hegg, and R. S. Sletten. 2012. "Isotopic constraints on the formation pathways of sulfate aerosol in the marine boundary layer of the subtropical northeast Atlantic Ocean." Journal of Geophysical Research: Atmospheres 117 (D6): [10.1029/2011jd016773]

    Fisher, J. A., D. J. Jacob, A. L. Soerensen, et al. H. M. Amos, A. Steffen, and E. M. Sunderland. 2012. "Riverine source of Arctic Ocean mercury inferred from atmospheric observations." Nature Geoscience 5 (7): 499-504 [10.1038/ngeo1478]

    Zhang, Y., L. Jaeglé, A. van Donkelaar, et al. R. V. Martin, C. D. Holmes, H. M. Amos, Q. Wang, R. Talbot, R. Artz, S. Brooks, W. Luke, T. M. Holsen, D. Felton, E. K. Miller, K. D. Perry, D. Schmeltz, A. Steffen, R. Tordon, P. Weiss-Penzias, and R. Zsolway. 2012. "Nested-grid simulation of mercury over North America." Atmospheric Chemistry and Physics 12 (14): 6095-6111 [10.5194/acp-12-6095-2012]

    Schauer, A. J., S. A. Kunasek, E. D. Sofen, et al. J. Erbland, J. Savarino, B. W. Johnson, H. M. Amos, R. Shaheen, M. Abaunza, T. L. Jackson, M. H. Thiemens, and B. Alexander. 2012. "Oxygen isotope exchange with quartz during pyrolysis of silver sulfate and silver nitrate." Rapid Communications in Mass Spectrometry 26 (18): 2151-2157 [10.1002/rcm.6332]

    Kunasek, S. A., B. Alexander, E. J. Steig, et al. E. D. Sofen, T. L. Jackson, M. H. Thiemens, J. R. McConnell, D. J. Gleason, and H. M. Amos. 2010. "Sulfate sources and oxidation chemistry over the past 230 years from sulfur and oxygen isotopes of sulfate in a West Antarctic ice core." Journal of Geophysical Research 115 (D18): D18313 [10.1029/2010jd013846]

    Non-Refereed

    Walker, J. T., G. M. Beachley, H. M. Amos, et al. J. S. Baron, J. Bash, R. Baumgardner, M. D. Bell, K. B. Benedict, X. Chen, D. W. Clow, A. Cole, J. G. Coughlin, K. Cruz, R. W. Daly, S. M. Decina, E. M. Elliot, M. E. Fenn, L. Ganzeveld, K. Gebhart, S. S. Isil, B. M. Kerschner, R. S. Larson, T. Lavery, G. G. Lear, T. Macy, M. A. Mast, K. Mishoe, K. H. Morris, P. E. Padgett, R. V. Pouyat, M. Puchalski, H. O. Pye, A. W. Rea, M. F. Rhodes, C. M. Rogers, R. Saylor, R. Scheffe, B. A. Schichtel, D. B. Schwede, G. A. Sexstone, B. C. Sive, P. H. Templer, T. Thompson, D. Tong, G. A. Wetherbee, T. H. Whitlow, Z. Wu, Z. Yu, and L. Zhang. 2019. "Science needs for continued development of total nitrogen deposition budgets in the United States." U.S. Environmental Protection Agency, Washington, DC EPA 601/R-19/001 391 [Full Text (Link)]

                                                                                                                                                                                            
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