Collaborative Research: Integrating GEOS-Chem Atmospheric Chemistry into the Community Earth System Model (CESM)

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

This project will integrate a state-of-science atmospheric chemistry model (GEOS-Chem) into an Earth System Model (ESM) that provides state-of-the-art computer simulations of the Earth's past, present, and future climate states. This effort is a partnership between the National Center for Atmospheric Research (NCAR) and several academic institutions, including Harvard and the Massachusetts Institute of Technology, to expand the national capabilities for climate modeling and atmospheric chemistry research. The first objective of the project is to deliver a mature GEOS-Chem module within the Community Earth System Model (CESM) Earth System Model in the first year of the project. The resulting CESM2 configuration with GEOS-Chem (CESM2-GC) will be evaluated by comparison to a large ensemble of atmospheric observations and to CAM-chem, that is the CESM2 configuration with chemistry. The second objective is to incorporate the GEOS-Chem emissions tool (HEMCO) into the model as an independent component in CESM2, not only for computing emissions but also as a general regridding and as an I/O tool. The third objective is to implement GEOS-Chem and HEMCO into the future-generation CESM as part of the System for Integrated Modeling of the Atmosphere (SIMA) with interoperable components linked by common infrastructure through the Common Physics Framework (CPF). This will involve further partitioning of GEOS-Chem into its chemistry and deposition subcomponents under the CPF. To assess the general performance of the model, global datasets will be used to benchmark the standard GEOS-Chem simulations at each version update. These include surface monitoring data for ozone and aerosol species, ozonesondes, satellite observations of ozone, aerosol optical depth, BrO, and other species, and vertical profiles from NASA aircraft campaigns for a large ensemble of species in coherent regions worldwide. The project will train several graduate students, enhance the nation's infrastructure for research by creating a new modeling tool, and increase the pool of personnel skilled in software engineering, a need strongly identified within the community. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.