Krzysztof Wargan

Krzysztof Wargan

  • RESEARCH SCIENTIST
  • 301.614.5521
  • NASA/GSFC
  • Mail Code: 610.1
  • Greenbelt , MD 20771
  • Employer: SCIENCE SYSTEMS AND APPLICATIONS INC
  • Research Interests

    Atmospheric ozone

     

    Constituent data assimilation

     

    Upper troposphere - lower stratosphere transport and dynamics

     

    Positions/Employment

    2/2012 - Present

    Chief Research Scientist

    Science Systems and Applications, Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt, MD 20771 USA  
    9/2010 - 1/2012

    Research Scientist

    Science Applications International Corporation, Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt, MD 20771 USA  
    6/2009 - 8/2010

    Research Assistant

    Imperial College London, Department of Physics Imperial College London London United Kingdom  
    1/2002 - 2/2009

    Support scientist

    Science Applications International Corporation, Global Modeling and Assimilation Office NASA Goddard Space Flight Center Greenbelt, MD 20771 USA  

    Education

     2001: PhD in mathematics, the George Washington University. Washington, DC

    1994: Master's degree in mathematics, University of Gdańsk, Gdańsk, Poland

    Professional Service

    • Member of the AMS Middle Atmosphere Committee
    • 2018 WMO/UNEP Scientific Assessment of Ozone Depletion: reviewer
    • SPARC Reanalysis Intercomparison Project (S-RIP): point of contact for NASA reanalyses
    • SPARC Reanalysis Intercomparison Project (S-RIP): Coauthor of Chapters 2, 4, and 7 of the S-RIP Report currently in preparation

    Grants

    04/20/2017 Modeling Analysis and Prediction 16-MAP16-0165, NASA

    A New Look at Stratospheric Chemistry With Multispecies Chemical Data Assimilation
     

    ; Principal Investigator

    Selected Publications

    Refereed

    Kramarova, N. A., J. R. Ziemke, L.-K. Huang, et al. J. R. Herman, K. Wargan, C. J. Seftor, G. J. Labow, and L. D. Oman. 2021. "Evaluation of Version 3 Total and Tropospheric Ozone Columns From Earth Polychromatic Imaging Camera on Deep Space Climate Observatory for Studying Regional Scale Ozone Variations." Frontiers in Remote Sensing, 2: [10.3389/frsen.2021.734071]

    Manney, G. L., M. L. Santee, Z. D. Lawrence, K. Wargan, and M. J. Schwartz. 2021. "A Moments View of Climatology and Variability of the Asian Summer Monsoon Anticyclone." Journal of Climate, 1-69 [10.1175/jcli-d-20-0729.1]

    Wargan, K., B. Weir, G. L. Manney, S. E. Cohn, and N. J. Livesey. 2020. "The Anomalous 2019 Antarctic Ozone Hole in the GEOS Constituent Data Assimilation System With MLS Observations." Journal of Geophysical Research: Atmospheres, 125 (18): [10.1029/2020jd033335]

    Orbe, C., K. Wargan, S. Pawson, and L. D. Oman. 2020. "Mechanisms Linked to Recent Ozone Decreases in the Northern Hemisphere Lower Stratosphere." Journal of Geophysical Research: Atmospheres, 125 (9): [10.1029/2019jd031631]

    Wargan, K., N. Kramarova, B. Weir, S. Pawson, and S. M. Davis. 2020. "Toward a Reanalysis of Stratospheric Ozone for Trend Studies: Assimilation of the Aura Microwave Limb Sounder and Ozone Mapping and Profiler Suite Limb Profiler Data." Journal of Geophysical Research: Atmospheres, 125 (4): [10.1029/2019jd031892]

    Tegtmeier, S., J. Anstey, S. Davis, et al. R. Dragani, Y. Harada, I. Ivanciu, R. Pilch Kedzierski, K. Krüger, B. Legras, C. Long, J. S. Wang, K. Wargan, and J. S. Wright. 2020. "Temperature and tropopause characteristics from reanalyses data in the tropical tropopause layer." Atmospheric Chemistry and Physics, 20 (2): 753-770 [10.5194/acp-20-753-2020]

    Lawrence, Z. D., G. L. Manney, and K. Wargan. 2018. "Reanalysis intercomparisons of stratospheric polar processing diagnostics." Atmospheric Chemistry and Physics, 18 (18): 13547-13579 [10.5194/acp-18-13547-2018]

    Wargan, K., C. Orbe, S. Pawson, et al. J. R. Ziemke, L. D. Oman, M. A. Olsen, L. Coy, and K. E. Knowland. 2018. "Recent decline in extratropical lower stratospheric ozone attributed to circulation changes." Geophysical Research Letters, [10.1029/2018gl077406]

    Levelt, P. F., J. Joiner, J. Tamminen, et al. J. P. Veefkind, P. K. Bhartia, D. C. Stein Zweers, B. N. Duncan, D. G. Streets, H. Eskes, R. van der A, C. McLinden, V. Fioletov, S. Carn, J. de Laat, M. DeLand, S. Marchenko, R. McPeters, J. Ziemke, D. Fu, X. Liu, K. Pickering, A. Apituley, G. González Abad, A. Arola, F. Boersma, C. Chan Miller, K. Chance, M. de Graaf, J. Hakkarainen, S. Hassinen, I. Ialongo, Q. Kleipool, N. Krotkov, C. Li, L. Lamsal, P. Newman, C. Nowlan, R. Suleiman, L. G. Tilstra, O. Torres, and K. Wargan. 2018. "The Ozone Monitoring Instrument: overview of 14 years in space." Atmospheric Chemistry and Physics, 18 (8): 5699-5745 [10.5194/acp-18-5699-2018]

    Nielsen, J. E., S. Pawson, A. Molod, et al. B. Auer, A. M. da Silva, A. R. Douglass, B. Duncan, Q. Liang, M. Manyin, L. D. Oman, W. Putman, S. E. Strahan, and K. Wargan. 2017. "Chemical Mechanisms and Their Applications in the Goddard Earth Observing System (GEOS) Earth System Model." Journal of Advances in Modeling Earth Systems, [10.1002/2017ms001011]

    Jaeglé, L., R. Wood, and K. Wargan. 2017. "Multi-year composite view of ozone enhancements and stratosphere-to-troposphere transport in dry intrusions of northern hemisphere extratropical cyclones." Journal of Geophysical Research: Atmospheres, [10.1002/2017jd027656]

    Davis, S. M., M. I. Hegglin, M. Fujiwara, et al. R. Dragani, Y. Harada, C. Kobayashi, C. Long, G. L. Manney, E. R. Nash, G. L. Potter, S. Tegtmeier, T. Wang, K. Wargan, and J. S. Wright. 2017. "Assessment of upper tropospheric and stratospheric water vapor and ozone in reanalyses as part of S-RIP." Atmospheric Chemistry and Physics, 17 (20): 12743-12778 [10.5194/acp-17-12743-2017]

    Manney, G. L., M. I. Hegglin, Z. D. Lawrence, et al. K. Wargan, L. F. Millán, M. J. Schwartz, M. L. Santee, A. Lambert, S. Pawson, B. W. Knosp, R. A. Fuller, and W. H. Daffer. 2017. "Reanalysis comparisons of upper tropospheric–lower stratospheric jets and multiple tropopauses." Atmospheric Chemistry and Physics, 17 (18): 11541-11566 [10.5194/acp-17-11541-2017]

    Knowland, K. E., L. E. Ott, B. N. Duncan, and K. Wargan. 2017. "Stratospheric intrusion-influenced ozone air quality exceedances investigated in the NASA MERRA-2 Reanalysis." Geophysical Research Letters, 44 (10): 691–10,701 [10.1002/2017gl074532]

    Gelaro, R., W. McCarty, M. J. Suárez, et al. R. Todling, A. Molod, L. Takacs, C. Randles, A. Darmenov, M. G. Bosilovich, R. Reichle, K. Wargan, L. Coy, R. Cullather, C. Draper, S. Akella, V. Buchard, A. Conaty, A. da Silva, W. Gu, G.-K. Kim, R. Koster, R. Lucchesi, D. Merkova, J. E. Nielsen, G. Partyka, S. Pawson, W. Putman, M. Rienecker, S. D. Schubert, M. Sienkiewicz, and B. Zhao. 2017. "The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)." Journal of Climate, 30: 5419–5454 [10.1175/jcli-d-16-0758.1]

    Wargan, K., G. Labow, S. Frith, et al. S. Pawson, N. Livesey, and G. Partyka. 2017. "Evaluation of the Ozone Fields in NASA’s MERRA-2 Reanalysis." Journal of Climate, 30 (8): 2961–2988 [10.1175/jcli-d-16-0699.1]

    Liu, J., J. M. Rodriguez, S. D. Steenrod, et al. A. R. Douglass, J. A. Logan, M. A. Olsen, K. Wargan, and J. R. Ziemke. 2017. "Causes of interannual variability over the southern hemispheric tropospheric ozone maximum." Atmospheric Chemistry and Physics, 17 (5): 3279-3299 [10.5194/acp-17-3279-2017]

    Fujiwara, M., J. S. Wright, G. L. Manney, et al. L. J. Gray, J. Anstey, T. Birner, S. Davis, E. P. Gerber, V. L. Harvey, M. I. Hegglin, C. R. Homeyer, J. A. Knox, K. Krüger, A. Lambert, C. S. Long, P. Martineau, B. M. Monge-Sanz, M. L. Santee, S. Tegtmeier, S. Chabrillat, D. G. Tan, D. R. Jackson, S. Polavarapu, G. P. Compo, R. Dragani, W. Ebisuzaki, Y. Harada, C. Kobayashi, W. McCarty, K. Onogi, S. Pawson, A. Simmons, K. Wargan, J. S. Whitaker, and C.-Z. Zou. 2017. "Introduction to the SPARC Reanalysis Intercomparison Project (S-RIP) and overview of the reanalysis systems." Atmospheric Chemistry and Physics, 1-52 [10.5194/acp-2016-652]

    Olsen, M. A., K. Wargan, and S. Pawson. 2016. "Tropospheric column ozone response to ENSO in GEOS-5 assimilation of OMI and MLS ozone data." Atmos. Chem. Phys., 16 (11): 7091-7103 [10.5194/acp-16-7091-2016]

    Ott, L. E., B. N. Duncan, A. M. Thompson, et al. G. Diskin, Z. Fasnacht, A. O. Langford, M. Lin, A. M. Molod, J. E. Nielsen, S. E. Pusede, K. Wargan, A. J. Weinheimer, and Y. Yoshida. 2016. "Frequency and impact of summertime stratospheric intrusions over Maryland during DISCOVER-AQ (2011): New evidence from NASA's GEOS-5 simulations." J. Geophys. Res. Atmos., [10.1002/2015jd024052]

    Coy, L., K. Wargan, A. M. Molod, W. R. McCarty, and S. Pawson. 2016. "Structure and Dynamics of the Quasi-Biennial Oscillation in MERRA-2." J. Climate, 29:14: 5339-5354 [10.1175/jcli-d-15-0809.1]

    Wargan, K., and L. Coy. 2016. "Strengthening of the Tropopause Inversion Layer During the 2009 Sudden Stratospheric Warming: A MERRA-2 Study." Journal of the Atmospheric Sciences, [10.1175/jas-d-15-0333.1]

    Wargan, K., S. Pawson, M. A. Olsen, et al. J. C. Witte, A. R. Douglass, J. R. Ziemke, S. E. Strahan, and J. E. Nielsen. 2015. "The Global Structure of Upper Troposphere-Lower Stratosphere Ozone in GEOS-5: A Multi-Year Assimilation of EOS Aura Data." J. Geophys. Res. - Atmos, 120: 2013-2036 [10.1002/2014JD022493]

    Ziemke, J. R., M. A. Olsen, J. C. Witte, et al. A. R. Douglass, S. E. Strahan, K. Wargan, X. Liu, M. Schoeberl, K. Yang, T. Kaplan, S. Pawson, B. N. Duncan, P. Newman, P. K. Bhartia, and M. K. Heney. 2014. "Assessment and applications of NASA ozone data products derived from Aura OMI/MLS satellite measurements in context of the GMI chemical transport model." J. Geophys. Res. Atmos., 119 (9): 5671-5699 [10.1002/2013JD020914]

    Remsberg, E., M. Natarajan, T. Fairlie, et al. K. Wargan, S. Pawson, L. Coy, G. Lingenfelser, and G. Kim. 2013. "On the inclusion of Limb Infrared Monitor of the Stratosphere version 6 ozone in a data assimilation system." J. Geophys. Res. Atmos., 118 (14): 7982-8000 [10.1002/jgrd.50566]

    Doughty, D. C., A. M. Thompson, M. R. Schoeberl, et al. I. Stajner, K. Wargan, and W. C. Hui. 2011. "An intercomparison of tropospheric ozone retrievals derived from two Aura instruments and in-situ measurements in western North America in 2006." J. Geophys. Res., doi: 116: D06303 [10.1029/2010JD014703]

    Wargan, K., S. Pawson, I. Stajner, and V. Thouret. 2010. "Spatial structure of assimilated ozone in the upper troposphere and lower stratosphere." J. Geophys. Res., 115 (D24): D24316 [10.1029/2010JD013941]

    Stajner, I., K. Wargan, S. Pawson, et al. H. Hayashi, L. P. Chang, R. C. Hudman, L. Froidevaux, N. Livesey, P. Levelt, A. M. Thompson, D. W. Tarasick, R. Stuebi, S. B. Andersen, M. Yela, G. Koenig-Laslo, F. J. Schmidlin, and J. C. Witte. 2008. "Assimilated Ozone from EOS-Aura: Evaluation of the Tropopause Region and Tropospheric Columns." J. Geophys. Res.-Atmos., 113: D15S32 [doi:10.1029/2007JD008863]

    Stajner, I., K. Wargan, L. Chang, et al. H. Hayashi, S. Pawson, and H. Nakajima. 2006. "Assimilation of ozone profiles from the Improved Limb Atmospheric Spectrometer-II: Study of Antarctic ozone." JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 111 (D11): [10.1029/2005JD006448]

    Wargan, K., I. Stajner, S. Pawson, R. Rood, and W. Tan. 2005. "Assimilation of ozone data from the Michelson Interferometer for Passive Atmospheric Sounding." QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, 131 (611): [10.1256/qj.04.184]

    Stajner, I., and K. Wargan. 2004. "Antarctic stratospheric ozone from the assimilation of occultation data." GEOPHYSICAL RESEARCH LETTERS, 31 (18): [10.1029/2004GL020846]

    Non-Refereed

    Mccarty, W. R., L. Coy, R. Gelaro, et al. A. Huang, D. Merkova, E. B. Smith, M. E. Sienkiewicz, and K. Wargan. 2016. "MERRA-2 Input Observations: Summary and Assessment." Technical Report Series on Global Modeling and Data Assimilation 46 (NASA/TM–2016-104606):

    Bosilovich, M. G., S. R. Akella, L. Coy, et al. R. I. Cullather, C. S. Draper, R. Gelaro, R. M. Kovach, Q. Liu, A. M. Molod, P. M. Norris, K. Wargan, C. Yang, R. H. Reichle, L. L. Takacs, Y. V. Vikhliaev, S. C. Bloom, A. Collow, S. Firth, G. J. Labow, G. S. Partyka, S. Pawson, O. Reale, S. D. Schubert, and M. J. Suarez. 2015. "MERRA-2: Initial Evaluation of the Climate." NASA Technical Report Series on Global Modeling and Data Assimilation 43 (NASA/TM–2015–10): 139 pp.

    Gelaro, R., W. M. Putman, S. Pawson, et al. C. S. Draper, A. M. Molod, P. M. Norris, L. E. Ott, N. C. Privé, O. Reale, D. Achuthavarier, M. G. Bosilovich, V. J. Buchard, W. C. Chao, L. Coy, R. I. Cullather, A. M. Da Silva, A. S. Darmenov, R. M. Errico, M. Fuentes, M.-J. Kim, R. D. Koster, W. R. Mccarty, J. Nattala, G. S. Partyka, S. D. Schubert, G. R. Vernieres, Y. V. Vikhliaev, and K. Wargan. 2015. "Evaluation of the 7-km GEOS-5 Nature Run." NASA Technical Report Series on Global Modeling and Data Assimilation 36 (NASA/TM-2014-104606):

    Selected Publications

    Refereed

    Kramarova, N. A., J. R. Ziemke, L.-K. Huang, et al. J. R. Herman, K. Wargan, C. J. Seftor, G. J. Labow, and L. D. Oman. 2021. "Evaluation of Version 3 Total and Tropospheric Ozone Columns From Earth Polychromatic Imaging Camera on Deep Space Climate Observatory for Studying Regional Scale Ozone Variations." Frontiers in Remote Sensing 2 [10.3389/frsen.2021.734071]

    Manney, G. L., M. L. Santee, Z. D. Lawrence, K. Wargan, and M. J. Schwartz. 2021. "A Moments View of Climatology and Variability of the Asian Summer Monsoon Anticyclone." Journal of Climate 1-69 [10.1175/jcli-d-20-0729.1]

    Wargan, K., B. Weir, G. L. Manney, S. E. Cohn, and N. J. Livesey. 2020. "The Anomalous 2019 Antarctic Ozone Hole in the GEOS Constituent Data Assimilation System With MLS Observations." Journal of Geophysical Research: Atmospheres 125 (18): [10.1029/2020jd033335]

    Orbe, C., K. Wargan, S. Pawson, and L. D. Oman. 2020. "Mechanisms Linked to Recent Ozone Decreases in the Northern Hemisphere Lower Stratosphere." Journal of Geophysical Research: Atmospheres 125 (9): [10.1029/2019jd031631]

    Wargan, K., N. Kramarova, B. Weir, S. Pawson, and S. M. Davis. 2020. "Toward a Reanalysis of Stratospheric Ozone for Trend Studies: Assimilation of the Aura Microwave Limb Sounder and Ozone Mapping and Profiler Suite Limb Profiler Data." Journal of Geophysical Research: Atmospheres 125 (4): [10.1029/2019jd031892]

    Tegtmeier, S., J. Anstey, S. Davis, et al. R. Dragani, Y. Harada, I. Ivanciu, R. Pilch Kedzierski, K. Krüger, B. Legras, C. Long, J. S. Wang, K. Wargan, and J. S. Wright. 2020. "Temperature and tropopause characteristics from reanalyses data in the tropical tropopause layer." Atmospheric Chemistry and Physics 20 (2): 753-770 [10.5194/acp-20-753-2020]

    Lawrence, Z. D., G. L. Manney, and K. Wargan. 2018. "Reanalysis intercomparisons of stratospheric polar processing diagnostics." Atmospheric Chemistry and Physics 18 (18): 13547-13579 [10.5194/acp-18-13547-2018]

    Wargan, K., C. Orbe, S. Pawson, et al. J. R. Ziemke, L. D. Oman, M. A. Olsen, L. Coy, and K. E. Knowland. 2018. "Recent decline in extratropical lower stratospheric ozone attributed to circulation changes." Geophysical Research Letters [10.1029/2018gl077406]

    Levelt, P. F., J. Joiner, J. Tamminen, et al. J. P. Veefkind, P. K. Bhartia, D. C. Stein Zweers, B. N. Duncan, D. G. Streets, H. Eskes, R. van der A, C. McLinden, V. Fioletov, S. Carn, J. de Laat, M. DeLand, S. Marchenko, R. McPeters, J. Ziemke, D. Fu, X. Liu, K. Pickering, A. Apituley, G. González Abad, A. Arola, F. Boersma, C. Chan Miller, K. Chance, M. de Graaf, J. Hakkarainen, S. Hassinen, I. Ialongo, Q. Kleipool, N. Krotkov, C. Li, L. Lamsal, P. Newman, C. Nowlan, R. Suleiman, L. G. Tilstra, O. Torres, and K. Wargan. 2018. "The Ozone Monitoring Instrument: overview of 14 years in space." Atmospheric Chemistry and Physics 18 (8): 5699-5745 [10.5194/acp-18-5699-2018]

    Nielsen, J. E., S. Pawson, A. Molod, et al. B. Auer, A. M. da Silva, A. R. Douglass, B. Duncan, Q. Liang, M. Manyin, L. D. Oman, W. Putman, S. E. Strahan, and K. Wargan. 2017. "Chemical Mechanisms and Their Applications in the Goddard Earth Observing System (GEOS) Earth System Model." Journal of Advances in Modeling Earth Systems [10.1002/2017ms001011]

    Jaeglé, L., R. Wood, and K. Wargan. 2017. "Multi-year composite view of ozone enhancements and stratosphere-to-troposphere transport in dry intrusions of northern hemisphere extratropical cyclones." Journal of Geophysical Research: Atmospheres [10.1002/2017jd027656]

    Davis, S. M., M. I. Hegglin, M. Fujiwara, et al. R. Dragani, Y. Harada, C. Kobayashi, C. Long, G. L. Manney, E. R. Nash, G. L. Potter, S. Tegtmeier, T. Wang, K. Wargan, and J. S. Wright. 2017. "Assessment of upper tropospheric and stratospheric water vapor and ozone in reanalyses as part of S-RIP." Atmospheric Chemistry and Physics 17 (20): 12743-12778 [10.5194/acp-17-12743-2017]

    Manney, G. L., M. I. Hegglin, Z. D. Lawrence, et al. K. Wargan, L. F. Millán, M. J. Schwartz, M. L. Santee, A. Lambert, S. Pawson, B. W. Knosp, R. A. Fuller, and W. H. Daffer. 2017. "Reanalysis comparisons of upper tropospheric–lower stratospheric jets and multiple tropopauses." Atmospheric Chemistry and Physics 17 (18): 11541-11566 [10.5194/acp-17-11541-2017]

    Knowland, K. E., L. E. Ott, B. N. Duncan, and K. Wargan. 2017. "Stratospheric intrusion-influenced ozone air quality exceedances investigated in the NASA MERRA-2 Reanalysis." Geophysical Research Letters 44 (10): 691–10,701 [10.1002/2017gl074532]

    Gelaro, R., W. McCarty, M. J. Suárez, et al. R. Todling, A. Molod, L. Takacs, C. Randles, A. Darmenov, M. G. Bosilovich, R. Reichle, K. Wargan, L. Coy, R. Cullather, C. Draper, S. Akella, V. Buchard, A. Conaty, A. da Silva, W. Gu, G.-K. Kim, R. Koster, R. Lucchesi, D. Merkova, J. E. Nielsen, G. Partyka, S. Pawson, W. Putman, M. Rienecker, S. D. Schubert, M. Sienkiewicz, and B. Zhao. 2017. "The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2)." Journal of Climate 30 5419–5454 [10.1175/jcli-d-16-0758.1]

    Wargan, K., G. Labow, S. Frith, et al. S. Pawson, N. Livesey, and G. Partyka. 2017. "Evaluation of the Ozone Fields in NASA’s MERRA-2 Reanalysis." Journal of Climate 30 (8): 2961–2988 [10.1175/jcli-d-16-0699.1]

    Liu, J., J. M. Rodriguez, S. D. Steenrod, et al. A. R. Douglass, J. A. Logan, M. A. Olsen, K. Wargan, and J. R. Ziemke. 2017. "Causes of interannual variability over the southern hemispheric tropospheric ozone maximum." Atmospheric Chemistry and Physics 17 (5): 3279-3299 [10.5194/acp-17-3279-2017]

    Fujiwara, M., J. S. Wright, G. L. Manney, et al. L. J. Gray, J. Anstey, T. Birner, S. Davis, E. P. Gerber, V. L. Harvey, M. I. Hegglin, C. R. Homeyer, J. A. Knox, K. Krüger, A. Lambert, C. S. Long, P. Martineau, B. M. Monge-Sanz, M. L. Santee, S. Tegtmeier, S. Chabrillat, D. G. Tan, D. R. Jackson, S. Polavarapu, G. P. Compo, R. Dragani, W. Ebisuzaki, Y. Harada, C. Kobayashi, W. McCarty, K. Onogi, S. Pawson, A. Simmons, K. Wargan, J. S. Whitaker, and C.-Z. Zou. 2017. "Introduction to the SPARC Reanalysis Intercomparison Project (S-RIP) and overview of the reanalysis systems." Atmospheric Chemistry and Physics 1-52 [10.5194/acp-2016-652]

    Olsen, M. A., K. Wargan, and S. Pawson. 2016. "Tropospheric column ozone response to ENSO in GEOS-5 assimilation of OMI and MLS ozone data." Atmos. Chem. Phys. 16 (11): 7091-7103 [10.5194/acp-16-7091-2016]

    Ott, L. E., B. N. Duncan, A. M. Thompson, et al. G. Diskin, Z. Fasnacht, A. O. Langford, M. Lin, A. M. Molod, J. E. Nielsen, S. E. Pusede, K. Wargan, A. J. Weinheimer, and Y. Yoshida. 2016. "Frequency and impact of summertime stratospheric intrusions over Maryland during DISCOVER-AQ (2011): New evidence from NASA's GEOS-5 simulations." J. Geophys. Res. Atmos. [10.1002/2015jd024052]

    Coy, L., K. Wargan, A. M. Molod, W. R. McCarty, and S. Pawson. 2016. "Structure and Dynamics of the Quasi-Biennial Oscillation in MERRA-2." J. Climate 29:14 5339-5354 [10.1175/jcli-d-15-0809.1]

    Wargan, K., and L. Coy. 2016. "Strengthening of the Tropopause Inversion Layer During the 2009 Sudden Stratospheric Warming: A MERRA-2 Study." Journal of the Atmospheric Sciences [10.1175/jas-d-15-0333.1]

    Wargan, K., S. Pawson, M. A. Olsen, et al. J. C. Witte, A. R. Douglass, J. R. Ziemke, S. E. Strahan, and J. E. Nielsen. 2015. "The Global Structure of Upper Troposphere-Lower Stratosphere Ozone in GEOS-5: A Multi-Year Assimilation of EOS Aura Data." J. Geophys. Res. - Atmos 120 2013-2036 [10.1002/2014JD022493]

    Ziemke, J. R., M. A. Olsen, J. C. Witte, et al. A. R. Douglass, S. E. Strahan, K. Wargan, X. Liu, M. Schoeberl, K. Yang, T. Kaplan, S. Pawson, B. N. Duncan, P. Newman, P. K. Bhartia, and M. K. Heney. 2014. "Assessment and applications of NASA ozone data products derived from Aura OMI/MLS satellite measurements in context of the GMI chemical transport model." J. Geophys. Res. Atmos. 119 (9): 5671-5699 [10.1002/2013JD020914]

    Remsberg, E., M. Natarajan, T. Fairlie, et al. K. Wargan, S. Pawson, L. Coy, G. Lingenfelser, and G. Kim. 2013. "On the inclusion of Limb Infrared Monitor of the Stratosphere version 6 ozone in a data assimilation system." J. Geophys. Res. Atmos. 118 (14): 7982-8000 [10.1002/jgrd.50566]

    Doughty, D. C., A. M. Thompson, M. R. Schoeberl, et al. I. Stajner, K. Wargan, and W. C. Hui. 2011. "An intercomparison of tropospheric ozone retrievals derived from two Aura instruments and in-situ measurements in western North America in 2006." J. Geophys. Res. doi: 116 D06303 [10.1029/2010JD014703]

    Wargan, K., S. Pawson, I. Stajner, and V. Thouret. 2010. "Spatial structure of assimilated ozone in the upper troposphere and lower stratosphere." J. Geophys. Res. 115 (D24): D24316 [10.1029/2010JD013941]

    Stajner, I., K. Wargan, S. Pawson, et al. H. Hayashi, L. P. Chang, R. C. Hudman, L. Froidevaux, N. Livesey, P. Levelt, A. M. Thompson, D. W. Tarasick, R. Stuebi, S. B. Andersen, M. Yela, G. Koenig-Laslo, F. J. Schmidlin, and J. C. Witte. 2008. "Assimilated Ozone from EOS-Aura: Evaluation of the Tropopause Region and Tropospheric Columns." J. Geophys. Res.-Atmos. 113 D15S32 [doi:10.1029/2007JD008863]

    Stajner, I., K. Wargan, L. Chang, et al. H. Hayashi, S. Pawson, and H. Nakajima. 2006. "Assimilation of ozone profiles from the Improved Limb Atmospheric Spectrometer-II: Study of Antarctic ozone." JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 111 (D11): [10.1029/2005JD006448]

    Wargan, K., I. Stajner, S. Pawson, R. Rood, and W. Tan. 2005. "Assimilation of ozone data from the Michelson Interferometer for Passive Atmospheric Sounding." QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY 131 (611): [10.1256/qj.04.184]

    Stajner, I., and K. Wargan. 2004. "Antarctic stratospheric ozone from the assimilation of occultation data." GEOPHYSICAL RESEARCH LETTERS 31 (18): [10.1029/2004GL020846]

    Non-Refereed

    Mccarty, W. R., L. Coy, R. Gelaro, et al. A. Huang, D. Merkova, E. B. Smith, M. E. Sienkiewicz, and K. Wargan. 2016. "MERRA-2 Input Observations: Summary and Assessment." Technical Report Series on Global Modeling and Data Assimilation 46 (NASA/TM–2016-104606):

    Bosilovich, M. G., S. R. Akella, L. Coy, et al. R. I. Cullather, C. S. Draper, R. Gelaro, R. M. Kovach, Q. Liu, A. M. Molod, P. M. Norris, K. Wargan, C. Yang, R. H. Reichle, L. L. Takacs, Y. V. Vikhliaev, S. C. Bloom, A. Collow, S. Firth, G. J. Labow, G. S. Partyka, S. Pawson, O. Reale, S. D. Schubert, and M. J. Suarez. 2015. "MERRA-2: Initial Evaluation of the Climate." NASA Technical Report Series on Global Modeling and Data Assimilation 43 (NASA/TM–2015–10) 139 pp.

    Gelaro, R., W. M. Putman, S. Pawson, et al. C. S. Draper, A. M. Molod, P. M. Norris, L. E. Ott, N. C. Privé, O. Reale, D. Achuthavarier, M. G. Bosilovich, V. J. Buchard, W. C. Chao, L. Coy, R. I. Cullather, A. M. Da Silva, A. S. Darmenov, R. M. Errico, M. Fuentes, M.-J. Kim, R. D. Koster, W. R. Mccarty, J. Nattala, G. S. Partyka, S. D. Schubert, G. R. Vernieres, Y. V. Vikhliaev, and K. Wargan. 2015. "Evaluation of the 7-km GEOS-5 Nature Run." NASA Technical Report Series on Global Modeling and Data Assimilation 36 (NASA/TM-2014-104606):

                                                                                                                                                                                            
    NASA Logo, National Aeronautics and Space Administration