GMAO Mission

The Global Modeling and Assimilation Office (GMAO) is a unique organization that uses computer models and data assimilation techniques to enhance NASA's program of Earth Observations.

GMAO members perform research, develop models and assimilation systems, and produce quasi-operational products in support of NASA's missions. The "Goddard Earth Observing System" (GEOS) family of models is used for applications across a wide range of spatial scales, from kilometers to many tens of kilometers. The modular structure of the models allow inclusion of a range of physical, chemical, and biological processes, which are chosen according to the application.

Originally formed to support NASA's "Earth Observing System" (EOS) mission, GMAO's role has evolved to include newer space- and aircraft-based observations. Data products are provided to the instrument teams from the three EOS platforms (Terra, Aqua and Aura), as well as to the science teams of NASA's latest space-based missions and for field campaigns. Forefront modeling studies support the planning of future missions. Advanced data assimilation studies demonstrate the impacts of NASA data types in weather prediction and other fields. NASA's historical observations are used alongside other data types to produce climate-quality datasets of the Earth System.

Research activities, including system development, focus on numerous time and space scales. This web site includes five major themes: "Weather Analysis and Prediction," "Seasonal-Decadal Analysis and Prediction," "Reanalysis," "Global Mesoscale Modeling," and "Observing System Science.". Although connected, these five thematic areas represent distinct activities in which the GMAO makes unique contributions to scientific understanding, bridging the gaps between intensive computer modeling and observations.

Modeling in the GMAO has adopted the Earth System Modeling Framework, which promotes a modular structure that allows model components to be connected together in a relatively straightforward manner. This approach promotes structured programming using modules or component models to treat specific physical, chemical, or biological processes. Used carefully, ESMF allows for proper treatment of coupling among different processes, such as the indirect and direct affects of aerosols on clouds and the terrestrial radiation balance.

The modular nature of ESMF has also allowed GMAO to make advances in Earth System modeling, without having to have front-line developers for all components of the Earth System. Collaborative endeavors include the development and implementation of components that originate in outside institutions, such as the atmospheric dynamical core, the physical ocean model, and the atmospheric aerosol modules, alongside in-house developments such as the atmospheric physics packages, the land-surface hydrology, and the ocean biogeochemistry modules.