Dr. Junhua Liu

Dr. Junhua Liu

  • Scientist
  • 301.614.5739
  • NASA/GSFC
  • Mail Code: 614
  • Greenbelt , MD 20771
  • Employer: USRA
  • Brief Bio

    Dr. Junhua Liu joined USRA/GESTAR in Nov 2013. Her current research focuses on quantifying the factors controlling the observed interannual variations and trends in tropospheric O3 and precursors during the past 20 years using an ensemble of satellite, aircraft, surface observations and GMI model, and investigating their interaction with the Earth’s climate. Prior to joining USRA, GSFC, Junhua worked as post-doctoral fellow and research associate at Harvard University on seasonal and interannual variations of carbon monoxide (CO) in the tropical troposphere and lower stratosphere and its inference for vertical transport using Aura satellite data and the GEOS-Chem model.

    Research Interests

    Dr. Liu's main research interests lie in understanding the processes affecting atmospheric composition in the troposphere and lower stratosphere, specifically the sources, chemical evolution and transport pathways.

     

    Current Projects

    Atmospheric Composition Analysis:

    Using global chemistry transport model (CTM) and chemistry climate models (CCM) along with in-situ and satellite measurements to understand the global distribution of atmospheric trace gases as well as their trends and interannual variations.

    My ongoing work is using a high-resolution (~50km) GEOS-5 Replay simulation with the Global Modeling Initiative (GMI) chemical mechanism, and its various tracer diagnostics to exam the spatial distribution and vertical extent of impacts of stratosphere – troposphere exchange (STE) on tropospheric ozone. Furthermore, quantifying the contributions of stratospheric and anthropogenic effects on tropospheric ozone radiative forcing and on regional air quality. Understanding how tropospheric ozone and associated radiative forcing will change in the future and investigating their interactions with Earth’s climate.
     

    Observational-Based Atmospheric Model Evaluation:

    Participating in the development of the Global Modeling and Assimilation Office (GMAO) composition forecasting system in GEOS-5, by providing ozone, PM2.5, NOX evaluations and building up benchmark plots of model outputs. Developing an observational-based evaluation package for the long-term CCM and CTM simulations.

    Field Mission Support and Data Analysis:

    Participating in the modeling effort for the Atmospheric Tomography Mission (ATom). Providing chemistry forecasting with GEOS-5 model for the missions. Using ATom CO, Ozone observations and model simulations to examine the spatial and temporal representativeness of ATom transects.

    Positions/Employment

    1/2017 - Present

    Scientist II

    USRA, NASA/GSFC, code 614
    11/2013 - 12/2016

    Scientist I

    USRA, NASA/GSFC, code 614
    7/2011 - 10/2013

    Research Associate

    Atmospheric Chemistry Modeling Group, Harvard University, Cambridge MA 02138
    7/2008 - 7/2011

    Postdoc Research Fellow

    Atmospheric Chemistry Modeling Group, Harvard University, Cambridge MA

    Education

    Ph.D.(2008), Climatology/Paleoclimatology, Duke University, Durham, NC

    B.S. (2002), Environmental Geochemistry, University of Science and Technology of China (USTC), Hefei, Anhui, China

    Professional Service

    Reviewer for several scientific journals including: Journal of Geophysical Research, Atmospheric Chemistry and Physics, Atmospheric Environment, and Geoscitific Model Development.

    Grants

    03/01/2017 - 02/29/2020 Quantifying the effects of STE on tropospheric ozone interannual variability and trends, radiative forcing, and air quality, NASA ROSES, NASA NRA #: NNH16ZDA001N-ACMAP
    PI ; 0.5 FTE
    11/01/2013 - 10/31/2016 Impact of meteorology and emissions on the interannual variations and trends of tropospheric ozone using the Global Model Initiative Combo model, NASA ROSES
    1.0 FTE

    Selected Publications

    Refereed

    Strode, S. A., J. Liu, L. Lait, et al. R. Commane, B. Daube, S. Wofsy, A. Conaty, P. Newman, and M. Prather. 2018. "Forecasting carbon monoxide on a global scale for the ATom-1 aircraft mission: insights from airborne and satellite observations and modeling." Atmospheric Chemistry and Physics, 18 (15): 10955-10971 [10.5194/acp-18-10955-2018]

    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]

    Prather, M. J., X. Zhu, C. M. Flynn, et al. S. A. Strode, J. M. Rodriguez, S. D. Steenrod, J. Liu, J.-F. Lamarque, A. M. Fiore, L. W. Horowitz, J. Mao, L. T. Murray, D. T. Shindell, and S. C. Wofsy. 2017. "Global atmospheric chemistry – which air matters." Atmospheric Chemistry and Physics, 17 (14): 9081-9102 [10.5194/acp-17-9081-2017]

    Ziemke, J. R., S. A. Strode, A. R. Douglass, et al. J. Joiner, A. Vasilkov, L. D. Oman, J. Liu, S. E. Strahan, P. K. Bhartia, and D. P. Haffner. 2017. "A cloud-ozone data product from Aura OMI and MLS satellite measurements." Atmospheric Measurement Techniques, 10 (11): 4067-4078 [10.5194/amt-10-4067-2017]

    Liu, J., J. M. Rodriguez, A. M. Thompson, et al. J. A. Logan, A. R. Douglass, M. A. Olsen, S. D. Steenrod, and F. Posny. 2016. "Origins of tropospheric ozone interannual variation over Réunion: A model investigation." J. Geophys. Res. Atmos., 121 (1): 521 - 537 [10.1002/ 2015JD023981]

    Crowley, T. J., S. P. Obrochta, and J. Liu. 2014. "Recent global temperature “plateau” in the context of a new proxy reconstruction." Earth's Future, 2 (5): 281-294 [10.1002/2013EF000216]

    Liu, J., J. A. Logan, L. T. Murray, H. C. Pumphrey, and I. A. Megretskaia. 2013. "Transport analysis and source attribution of seasonal and interannual variability of CO in the tropical upper troposphere and lower stratosphere,." Atmos. Chem. Phys., 13: 129-146 [10.5194/acp-13-129-2013]

    Liu, J., J. A. Logan, D. B. Jones, et al. N. J. Livesey, I. Megretskaia, C. Carouge, and P. Nedelec. 2010. "Analysis of CO in the tropical troposphere using Aura satellite data and the GEOS-Chem model: insights into transport characteristics of the GEOS meteorological products." Atmos. Chem. Phys., 10: 12207–12232 [10.5194/acp-10-12207-2010]

    Liu, G., L. Zheng, N. S. Duzgoren-Aydin, et al. L. Gao, J. Liu, and Z. Peng. 2007. "Health Effects of Arsenic, Fluorine, and Selenium from Indoor Burning of Chinese Coal." Reviews of Environmental Contamination and Toxicology, 89-106 [10.1007/978-0-387-35368-5_4]

    Ballantyne, A. P., M. Lavine, T. J. Crowley, J. Liu, and P. Baker. 2005. "Meta-analysis of tropical surface temperatures during the Last Glacial Maximum." Geophys. Res. Lett, 52 (5): [10.1029/2004GL021217]

    Loarie, S. R., S. Chakraborty, K. Dexter, et al. A. Fleming-Davies, A. Gronewold, J. Liu, A. McBride, and E. Pollina. . "Density dependence and population growth: Evaluating classical and Bayesian approaches to parameter estimation and model selection. In J.S. Clark "Statistical computation for environmental sci. in R". ."

    Brief Bio

    Dr. Junhua Liu joined USRA/GESTAR in Nov 2013. Her current research focuses on quantifying the factors controlling the observed interannual variations and trends in tropospheric O3 and precursors during the past 20 years using an ensemble of satellite, aircraft, surface observations and GMI model, and investigating their interaction with the Earth’s climate. Prior to joining USRA, GSFC, Junhua worked as post-doctoral fellow and research associate at Harvard University on seasonal and interannual variations of carbon monoxide (CO) in the tropical troposphere and lower stratosphere and its inference for vertical transport using Aura satellite data and the GEOS-Chem model.

    Selected Publications

    Refereed

    Strode, S. A., J. Liu, L. Lait, et al. R. Commane, B. Daube, S. Wofsy, A. Conaty, P. Newman, and M. Prather. 2018. "Forecasting carbon monoxide on a global scale for the ATom-1 aircraft mission: insights from airborne and satellite observations and modeling." Atmospheric Chemistry and Physics 18 (15): 10955-10971 [10.5194/acp-18-10955-2018]

    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]

    Prather, M. J., X. Zhu, C. M. Flynn, et al. S. A. Strode, J. M. Rodriguez, S. D. Steenrod, J. Liu, J.-F. Lamarque, A. M. Fiore, L. W. Horowitz, J. Mao, L. T. Murray, D. T. Shindell, and S. C. Wofsy. 2017. "Global atmospheric chemistry – which air matters." Atmospheric Chemistry and Physics 17 (14): 9081-9102 [10.5194/acp-17-9081-2017]

    Ziemke, J. R., S. A. Strode, A. R. Douglass, et al. J. Joiner, A. Vasilkov, L. D. Oman, J. Liu, S. E. Strahan, P. K. Bhartia, and D. P. Haffner. 2017. "A cloud-ozone data product from Aura OMI and MLS satellite measurements." Atmospheric Measurement Techniques 10 (11): 4067-4078 [10.5194/amt-10-4067-2017]

    Liu, J., J. M. Rodriguez, A. M. Thompson, et al. J. A. Logan, A. R. Douglass, M. A. Olsen, S. D. Steenrod, and F. Posny. 2016. "Origins of tropospheric ozone interannual variation over Réunion: A model investigation." J. Geophys. Res. Atmos. 121 (1): 521 - 537 [10.1002/ 2015JD023981]

    Crowley, T. J., S. P. Obrochta, and J. Liu. 2014. "Recent global temperature “plateau” in the context of a new proxy reconstruction." Earth's Future 2 (5): 281-294 [10.1002/2013EF000216]

    Liu, J., J. A. Logan, L. T. Murray, H. C. Pumphrey, and I. A. Megretskaia. 2013. "Transport analysis and source attribution of seasonal and interannual variability of CO in the tropical upper troposphere and lower stratosphere,." Atmos. Chem. Phys. 13 129-146 [10.5194/acp-13-129-2013]

    Liu, J., J. A. Logan, D. B. Jones, et al. N. J. Livesey, I. Megretskaia, C. Carouge, and P. Nedelec. 2010. "Analysis of CO in the tropical troposphere using Aura satellite data and the GEOS-Chem model: insights into transport characteristics of the GEOS meteorological products." Atmos. Chem. Phys. 10 12207–12232 [10.5194/acp-10-12207-2010]

    Liu, G., L. Zheng, N. S. Duzgoren-Aydin, et al. L. Gao, J. Liu, and Z. Peng. 2007. "Health Effects of Arsenic, Fluorine, and Selenium from Indoor Burning of Chinese Coal." Reviews of Environmental Contamination and Toxicology 89-106 [10.1007/978-0-387-35368-5_4]

    Ballantyne, A. P., M. Lavine, T. J. Crowley, J. Liu, and P. Baker. 2005. "Meta-analysis of tropical surface temperatures during the Last Glacial Maximum." Geophys. Res. Lett 52 (5): [10.1029/2004GL021217]

    Loarie, S. R., S. Chakraborty, K. Dexter, et al. A. Fleming-Davies, A. Gronewold, J. Liu, A. McBride, and E. Pollina. . "Density dependence and population growth: Evaluating classical and Bayesian approaches to parameter estimation and model selection. In J.S. Clark "Statistical computation for environmental sci. in R". ."

                                                                                                                                                                                            
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