In order to address questions pertaining to atmospheric composition, chemical models of varying complexity have been implemented as modules into the GEOS-5 General Circulation Model. Simple chemical modules (with linearized production and loss) are used to investigate issues related to atmospheric transport and emissions. More complex chemical modules have been implemented through various collaborative ventures:

  1. A detailed representation of stratospheric chemistry, developed in the Atmospheric Chemistry and Dynamics Laboratory (Code 614) at NASA GSFC is been used to investigate connections between ozone and the circulation. This version of GEOS-5 with chemistry constitutes the first version of the GEOS CCM (Chemistry-Climate Model) which was used extensively in the WMO-SPARC "Chemistry-Climate Model Validation" (CCMVal) exercise and contributed to the WMO-UNEP Scientific Assessment of Ozone Depletion. This model version is also being used as a coupled "Atmosphere-Ocean" model, in collaborative projects funded by NASA's Modeling and Analysis Program (MAP).
  2. The stratosphere-troposphere chemical mechanism developed by NASA’s Global Modeling Initiative (GMI), implemented more recently into GEOS-5, is used in a more complex version of the GEOS CCM — this allows for a more accurate computation of the radiative forcing of ozone on climate than in the model with stratosphere-only chemistry. Pioneering simulations are being performed to demonstrate our ability to represent chemistry-circulation coupling at ultra-high spatial resolution (about 25km), which allow us to apply NASA's High-Performance Computing systems to topical issues related to air pollution.
  3. In collaboration with scientists at Harvard University, the GEOS-Chem chemical mechanism is being implemented into GEOS-5. This coupled model will be used to address several questions related to pollutant emissions, especially in an assimilation system that uses NASA’s satellite observations.


» Chemistry-Climate Model Project

» High-resolution GEOS-5 simulations of stratospheric ozone intrusions (GMAO article with animation)


« GMAO Modeling