Christoph Andrea Keller

Christoph Andrea Keller

  • SCIENTIST
  • 301.614.6945
  • NASA/GSFC
  • Mail Code: 610.1
  • Greenbelt , MD 20771
  • Employer: UNIVERSITIES SPACE RESEARCH ASSOCIATION
  • Research Interests

    Tropospheric composition

    Dr. Christoph Keller’s research is focused on improving the representation of reactive trace gases in atmospheric models. He uses the GEOS-Chem chemistry module within the GEOS Earth System model to simulate and better understand the evolution of air pollutants such as ozone and nitrogen dioxide. He uses atmospheric observations to further improve model constraints, in particular emissions. He also develops new methods to emulate processes relevant to atmospheric chemistry based on machine learning. Keller is the principal developer of the GEOS composition forecast (GEOS-CF) model.


     

    Positions/Employment

    1/2016 - Present

    Scientist / Senior Scientist

    NASA GMAO / USRA, Greenbelt, Maryland
    • Development of a multispecies data assimilation system for atmospheric constituents (ozone, carbon monoxide, nitrogen dioxide).
    • Development and maintenance of the GEOS-Chem atmospheric chemistry module within GEOS-5.
    2/2012 - 1/2016

    Research Associate

    School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
    • Development of the Harvard NASA emissions component (HEMCO), a stand-alone software component for calculating emissions in global atmospheric models. Additional information about HEMCO can be found at http://wiki.seas.harvard.edu/geos-chem/index.php/HEMCO.
    • Coupling of the GEOS-Chem chemical transport model to the GEOS-5 Earth System Model.

    Education

    • Ph.D., Atmospheric and Climate Science, EMPA / ETH Zurich (2012)
    • M.Sc., Atmospheric and Climate Science, ETH Zurich (2008)
    • B.Sc., Earth Sciences, ETH Zurich (2006)

    Publications

    Refereed

    Malings, C., K. E. Knowland, C. A. Keller, and S. E. Cohn. 2021. "Sub‐City Scale Hourly Air Quality Forecasting by Combining Models, Satellite Observations, and Ground Measurements." Earth and Space Science, 8 (7): [10.1029/2021ea001743]

    Johnson, M. S., K. Strawbridge, K. E. Knowland, C. Keller, and M. Travis. 2021. "Long-range transport of Siberian biomass burning emissions to North America during FIREX-AQ." Atmospheric Environment, 252: 118241 [10.1016/j.atmosenv.2021.118241]

    Keller, C. A., K. E. Knowland, B. N. Duncan, et al. J. Liu, D. C. Anderson, S. Das, R. A. Lucchesi, E. W. Lundgren, J. M. Nicely, E. Nielsen, L. E. Ott, E. Saunders, S. A. Strode, P. A. Wales, D. J. Jacob, and S. Pawson. 2021. "Description of the NASA GEOS Composition Forecast Modeling System GEOS‐CF v1.0." Journal of Advances in Modeling Earth Systems, 13 (4): [10.1029/2020ms002413]

    Keller, C. A., M. J. Evans, K. E. Knowland, et al. C. A. Hasenkopf, S. Modekurty, R. A. Lucchesi, T. Oda, B. B. Franca, F. C. Mandarino, M. V. Díaz Suárez, R. G. Ryan, L. H. Fakes, and S. Pawson. 2021. "Global impact of COVID-19 restrictions on the surface concentrations of nitrogen dioxide and ozone." Atmospheric Chemistry and Physics, 21 (5): 3555-3592 [10.5194/acp-21-3555-2021]

    DeLang, M. N., J. S. Becker, K.-L. Chang, et al. M. L. Serre, O. R. Cooper, M. G. Schultz, S. Schröder, X. Lu, L. Zhang, M. Deushi, B. Josse, C. A. Keller, J.-F. Lamarque, M. Lin, J. Liu, V. Marécal, S. A. Strode, K. Sudo, S. Tilmes, L. Zhang, S. E. Cleland, E. L. Collins, M. Brauer, and J. J. West. 2021. "Mapping Yearly Fine Resolution Global Surface Ozone through the Bayesian Maximum Entropy Data Fusion of Observations and Model Output for 1990–2017." Environmental Science & Technology, acs.est.0c07742 [10.1021/acs.est.0c07742]

    Forster, P. M., H. I. Forster, M. J. Evans, et al. M. J. Gidden, C. D. Jones, C. A. Keller, R. D. Lamboll, C. L. Quéré, J. Rogelj, D. Rosen, C.-F. Schleussner, T. B. Richardson, C. J. Smith, and S. T. Turnock. 2020. "Current and future global climate impacts resulting from COVID-19." Nature Climate Change, (Accepted) [10.1038/s41558-020-0883-0]

    Strode, S. A., J. S. Wang, M. Manyin, et al. B. Duncan, R. Hossaini, C. A. Keller, S. E. Michel, and J. W. White. 2020. "Strong sensitivity of the isotopic composition of methane to the plausible range of tropospheric chlorine." Atmospheric Chemistry and Physics, 20 (14): 8405-8419 [10.5194/acp-20-8405-2020]

    Lin, H., X. Feng, T.-M. Fu, et al. H. Tian, Y. Ma, L. Zhang, D. J. Jacob, R. M. Yantosca, M. P. Sulprizio, E. W. Lundgren, J. Zhuang, Q. Zhang, X. Lu, L. Zhang, L. Shen, J. Guo, S. D. Eastham, and C. A. Keller. 2020. "WRF-GC (v1.0): online coupling of WRF (v3.9.1.1) and GEOS-Chem (v12.2.1) for regional atmospheric chemistry modeling – Part 1: Description of the one-way model." Geoscientific Model Development, 13 (7): 3241-3265 [10.5194/gmd-13-3241-2020]

    Velegar, M., N. B. Erichson, C. A. Keller, and J. N. Kutz. 2019. "Scalable diagnostics for global atmospheric chemistry using Ristretto library (version 1.0)." Geoscientific Model Development, 12 (4): 1525-1539 [10.5194/gmd-12-1525-2019]

    Keller, C. A., and M. J. Evans. 2019. "Application of random forest regression to the calculation of gas-phase chemistry within the GEOS-Chem chemistry model v10." Geoscientific Model Development, 12 (3): 1209-1225 [10.5194/gmd-12-1209-2019]

    Chang, K.-L., O. R. Cooper, J. J. West, et al. M. L. Serre, M. G. Schultz, M. Lin, V. Marécal, B. Josse, M. Deushi, K. Sudo, J. Liu, and C. A. Keller. 2019. "A new method (M3Fusion-v1) for combining observations and multiple model output for an improved estimate of the global surface ozone distribution." Geoscientific Model Development, 12 (3): 955-978 [10.5194/gmd-12-955-2019]

    Hu, L., C. A. Keller, M. S. Long, et al. T. Sherwen, B. Auer, A. Da Silva, J. E. Nielsen, S. Pawson, M. A. Thompson, A. L. Trayanov, K. R. Travis, S. K. Grange, M. J. Evans, and D. J. Jacob. 2018. "Global simulation of tropospheric chemistry at 12.5 km resolution: performance and evaluation of the GEOS-Chem chemical module (v10-1) within the NASA GEOS Earth system model (GEOS-5 ESM)." Geoscientific Model Development, 11 (11): 4603-4620 [10.5194/gmd-11-4603-2018]

    Weagle, C. L., G. Snider, C. Li, et al. A. van Donkelaar, S. Philip, P. Bissonnette, J. Burke, J. Jackson, R. Latimer, E. Stone, I. Abboud, C. Akoshile, N. X. Anh, J. R. Brook, A. Cohen, J. Dong, M. D. Gibson, D. Griffith, K. B. He, B. N. Holben, R. Kahn, C. A. Keller, J. S. Kim, N. Lagrosas, P. Lestari, Y. L. Khian, Y. Liu, E. A. Marais, J. V. Martins, A. Misra, U. Muliane, R. Pratiwi, E. J. Quel, A. Salam, L. Segev, S. N. Tripathi, C. Wang, Q. Zhang, M. Brauer, Y. Rudich, and R. V. Martin. 2018. "Global Sources of Fine Particulate Matter: Interpretation of PM2.5 Chemical Composition Observed by SPARTAN using a Global Chemical Transport Model." Environmental Science & Technology, 52 (20): acs.est.8b01658 [10.1021/acs.est.8b01658]

    Eastham, S. D., M. S. Long, C. A. Keller, et al. E. Lundgren, R. M. Yantosca, J. Zhuang, C. Li, C. J. Lee, M. Yannetti, B. M. Auer, T. L. Clune, J. Kouatchou, W. M. Putman, M. A. Thompson, A. L. Trayanov, A. M. Molod, R. V. Martin, and D. J. Jacob. 2018. "GEOS-Chem High Performance (GCHP v11-02c): a next-generation implementation of the GEOS-Chem chemical transport model for massively parallel applications." Geoscientific Model Development, 11 (7): 2941-2953 [10.5194/gmd-11-2941-2018]

    Yu, K., C. A. Keller, D. J. Jacob, et al. A. M. Molod, S. D. Eastham, and M. S. Long. 2018. "Errors and improvements in the use of archived meteorological data for chemical transport modeling: an analysis using GEOS-Chem v11-01 driven by GEOS-5 meteorology." Geoscientific Model Development, 11 (1): 305-319 [10.5194/gmd-11-305-2018]

    Zhu, J., X. Xia, J. Wang, et al. J. Zhang, C. Wiedinmyer, J. A. Fisher, and C. A. Keller. 2017. "Impact of Southeast Asian smoke on aerosol properties in Southwest China: First comparison of model simulations with satellite and ground observations." Journal of Geophysical Research: Atmospheres, 122 (7): 3904-3919 [10.1002/2016jd025793]

    Long, M. S., R. Yantosca, J. E. Nielsen, et al. C. A. Keller, A. da Silva, M. P. Sulprizio, S. Pawson, and D. J. Jacob. 2015. "Development of a grid-independent GEOS-Chem chemical transport model (v9-02) as an atmospheric chemistry module for Earth system models." Geosci. Model Dev., 8 (3): 595-602 [10.5194/gmd-8-595-2015]

    Keller, C. A., M. S. Long, R. M. Yantosca, et al. A. M. Da Silva, S. Pawson, and D. J. Jacob. 2014. "HEMCO v1.0: a versatile, ESMF-compliant component for calculating emissions in atmospheric models." Geoscientific Model Development, 7 (4): 1409-1417 [10.5194/gmd-7-1409-2014]

    Non-Refereed

    Knowland, K. E., C. A. Keller, and R. A. Lucchesi. 2020. "File Specification for GEOS-CF Products." GMAO Office Note No. 17 (Version 1.1), 37pp, available from http://gmao.gsfc.nasa.gov/pubs/office_notes

    Publications

    Refereed

    Malings, C., K. E. Knowland, C. A. Keller, and S. E. Cohn. 2021. "Sub‐City Scale Hourly Air Quality Forecasting by Combining Models, Satellite Observations, and Ground Measurements." Earth and Space Science 8 (7): [10.1029/2021ea001743]

    Johnson, M. S., K. Strawbridge, K. E. Knowland, C. Keller, and M. Travis. 2021. "Long-range transport of Siberian biomass burning emissions to North America during FIREX-AQ." Atmospheric Environment 252 118241 [10.1016/j.atmosenv.2021.118241]

    Keller, C. A., K. E. Knowland, B. N. Duncan, et al. J. Liu, D. C. Anderson, S. Das, R. A. Lucchesi, E. W. Lundgren, J. M. Nicely, E. Nielsen, L. E. Ott, E. Saunders, S. A. Strode, P. A. Wales, D. J. Jacob, and S. Pawson. 2021. "Description of the NASA GEOS Composition Forecast Modeling System GEOS‐CF v1.0." Journal of Advances in Modeling Earth Systems 13 (4): [10.1029/2020ms002413]

    Keller, C. A., M. J. Evans, K. E. Knowland, et al. C. A. Hasenkopf, S. Modekurty, R. A. Lucchesi, T. Oda, B. B. Franca, F. C. Mandarino, M. V. Díaz Suárez, R. G. Ryan, L. H. Fakes, and S. Pawson. 2021. "Global impact of COVID-19 restrictions on the surface concentrations of nitrogen dioxide and ozone." Atmospheric Chemistry and Physics 21 (5): 3555-3592 [10.5194/acp-21-3555-2021]

    DeLang, M. N., J. S. Becker, K.-L. Chang, et al. M. L. Serre, O. R. Cooper, M. G. Schultz, S. Schröder, X. Lu, L. Zhang, M. Deushi, B. Josse, C. A. Keller, J.-F. Lamarque, M. Lin, J. Liu, V. Marécal, S. A. Strode, K. Sudo, S. Tilmes, L. Zhang, S. E. Cleland, E. L. Collins, M. Brauer, and J. J. West. 2021. "Mapping Yearly Fine Resolution Global Surface Ozone through the Bayesian Maximum Entropy Data Fusion of Observations and Model Output for 1990–2017." Environmental Science & Technology acs.est.0c07742 [10.1021/acs.est.0c07742]

    Forster, P. M., H. I. Forster, M. J. Evans, et al. M. J. Gidden, C. D. Jones, C. A. Keller, R. D. Lamboll, C. L. Quéré, J. Rogelj, D. Rosen, C.-F. Schleussner, T. B. Richardson, C. J. Smith, and S. T. Turnock. 2020. "Current and future global climate impacts resulting from COVID-19." Nature Climate Change (Accepted) [10.1038/s41558-020-0883-0]

    Strode, S. A., J. S. Wang, M. Manyin, et al. B. Duncan, R. Hossaini, C. A. Keller, S. E. Michel, and J. W. White. 2020. "Strong sensitivity of the isotopic composition of methane to the plausible range of tropospheric chlorine." Atmospheric Chemistry and Physics 20 (14): 8405-8419 [10.5194/acp-20-8405-2020]

    Lin, H., X. Feng, T.-M. Fu, et al. H. Tian, Y. Ma, L. Zhang, D. J. Jacob, R. M. Yantosca, M. P. Sulprizio, E. W. Lundgren, J. Zhuang, Q. Zhang, X. Lu, L. Zhang, L. Shen, J. Guo, S. D. Eastham, and C. A. Keller. 2020. "WRF-GC (v1.0): online coupling of WRF (v3.9.1.1) and GEOS-Chem (v12.2.1) for regional atmospheric chemistry modeling – Part 1: Description of the one-way model." Geoscientific Model Development 13 (7): 3241-3265 [10.5194/gmd-13-3241-2020]

    Velegar, M., N. B. Erichson, C. A. Keller, and J. N. Kutz. 2019. "Scalable diagnostics for global atmospheric chemistry using Ristretto library (version 1.0)." Geoscientific Model Development 12 (4): 1525-1539 [10.5194/gmd-12-1525-2019]

    Keller, C. A., and M. J. Evans. 2019. "Application of random forest regression to the calculation of gas-phase chemistry within the GEOS-Chem chemistry model v10." Geoscientific Model Development 12 (3): 1209-1225 [10.5194/gmd-12-1209-2019]

    Chang, K.-L., O. R. Cooper, J. J. West, et al. M. L. Serre, M. G. Schultz, M. Lin, V. Marécal, B. Josse, M. Deushi, K. Sudo, J. Liu, and C. A. Keller. 2019. "A new method (M3Fusion-v1) for combining observations and multiple model output for an improved estimate of the global surface ozone distribution." Geoscientific Model Development 12 (3): 955-978 [10.5194/gmd-12-955-2019]

    Hu, L., C. A. Keller, M. S. Long, et al. T. Sherwen, B. Auer, A. Da Silva, J. E. Nielsen, S. Pawson, M. A. Thompson, A. L. Trayanov, K. R. Travis, S. K. Grange, M. J. Evans, and D. J. Jacob. 2018. "Global simulation of tropospheric chemistry at 12.5 km resolution: performance and evaluation of the GEOS-Chem chemical module (v10-1) within the NASA GEOS Earth system model (GEOS-5 ESM)." Geoscientific Model Development 11 (11): 4603-4620 [10.5194/gmd-11-4603-2018]

    Weagle, C. L., G. Snider, C. Li, et al. A. van Donkelaar, S. Philip, P. Bissonnette, J. Burke, J. Jackson, R. Latimer, E. Stone, I. Abboud, C. Akoshile, N. X. Anh, J. R. Brook, A. Cohen, J. Dong, M. D. Gibson, D. Griffith, K. B. He, B. N. Holben, R. Kahn, C. A. Keller, J. S. Kim, N. Lagrosas, P. Lestari, Y. L. Khian, Y. Liu, E. A. Marais, J. V. Martins, A. Misra, U. Muliane, R. Pratiwi, E. J. Quel, A. Salam, L. Segev, S. N. Tripathi, C. Wang, Q. Zhang, M. Brauer, Y. Rudich, and R. V. Martin. 2018. "Global Sources of Fine Particulate Matter: Interpretation of PM2.5 Chemical Composition Observed by SPARTAN using a Global Chemical Transport Model." Environmental Science & Technology 52 (20): acs.est.8b01658 [10.1021/acs.est.8b01658]

    Eastham, S. D., M. S. Long, C. A. Keller, et al. E. Lundgren, R. M. Yantosca, J. Zhuang, C. Li, C. J. Lee, M. Yannetti, B. M. Auer, T. L. Clune, J. Kouatchou, W. M. Putman, M. A. Thompson, A. L. Trayanov, A. M. Molod, R. V. Martin, and D. J. Jacob. 2018. "GEOS-Chem High Performance (GCHP v11-02c): a next-generation implementation of the GEOS-Chem chemical transport model for massively parallel applications." Geoscientific Model Development 11 (7): 2941-2953 [10.5194/gmd-11-2941-2018]

    Yu, K., C. A. Keller, D. J. Jacob, et al. A. M. Molod, S. D. Eastham, and M. S. Long. 2018. "Errors and improvements in the use of archived meteorological data for chemical transport modeling: an analysis using GEOS-Chem v11-01 driven by GEOS-5 meteorology." Geoscientific Model Development 11 (1): 305-319 [10.5194/gmd-11-305-2018]

    Zhu, J., X. Xia, J. Wang, et al. J. Zhang, C. Wiedinmyer, J. A. Fisher, and C. A. Keller. 2017. "Impact of Southeast Asian smoke on aerosol properties in Southwest China: First comparison of model simulations with satellite and ground observations." Journal of Geophysical Research: Atmospheres 122 (7): 3904-3919 [10.1002/2016jd025793]

    Long, M. S., R. Yantosca, J. E. Nielsen, et al. C. A. Keller, A. da Silva, M. P. Sulprizio, S. Pawson, and D. J. Jacob. 2015. "Development of a grid-independent GEOS-Chem chemical transport model (v9-02) as an atmospheric chemistry module for Earth system models." Geosci. Model Dev. 8 (3): 595-602 [10.5194/gmd-8-595-2015]

    Keller, C. A., M. S. Long, R. M. Yantosca, et al. A. M. Da Silva, S. Pawson, and D. J. Jacob. 2014. "HEMCO v1.0: a versatile, ESMF-compliant component for calculating emissions in atmospheric models." Geoscientific Model Development 7 (4): 1409-1417 [10.5194/gmd-7-1409-2014]

    Non-Refereed

    Knowland, K. E., C. A. Keller, and R. A. Lucchesi. 2020. "File Specification for GEOS-CF Products." GMAO Office Note No. 17 (Version 1.1), 37pp, available from http://gmao.gsfc.nasa.gov/pubs/office_notes

                                                                                                                                                                                            
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