Jennifer A. Logan
Senior Research Fellow
School of Engineering and Applied Sciences
Harvard University

DEVELOPMENT AND ANALYSIS OF THE GLOBAL MODELING INITIATIVE (GMI) MODEL

BACKGROUND:

The Global Modeling Initiative (GMI) is developing and maintaining a state-of-the-art modular 3-D chemistry and transport model that can be used for scientific studies, as well as to assess the impact of various natural and anthropogenic perturbations on atmospheric composition. The GMI model also serves as a test-bed for model improvements.  We have been involved in the development of the GMI model since its early days.  The GMI model was designed to be able to run with different meteorological datasets, chemistry schemes, emissions, etc.  At present the model is run with meteorological fields from the NASA/Goddard GEOS-4 GCM, and with GEOS-4 assimilated fields.  The most recent version of the model, the Combo model, includes stratospheric and tropospheric chemistry.  Several elements of the tropospheric part of the model have their heritage in the GEOS-Chem model, including the chemical scheme and the emissions.

OBJECTIVES:

  • To reduce uncertainties in model results and predictions by understanding processes that contribute most to differences in model simulations, and by evaluating model results with observations
  • To contribute to the assessment of anthropogenic perturbations to the Earth system.

APPROACH:

  • Contribute updates to GEOS-Chem algorithms and data sets to the GMI model
  • Evaluate the GMI tropospheric simulations with surface, sonde, aircraft, and satellite data
  • Participate in the Hemispheric Transport of Air Pollution (HTAP) Study

PEOPLE: Jennifer Logan, Inna Megretskaia

COLLABORATORS: Jose Rodriguez, Bryan Duncan, David Considine, Susan Strahan

REFERENCES:

  • Considine, D. B., J. A. Logan, and M. A. Olsen, Evaluation of near-tropopause ozone distributions in the Global Modeling Initiative combined stratosphere/troposphere model with ozonesonde data (2008), Atmos. Chem. Phys., 8, 2365-2385. [PDF]

SUPPORT: NASA