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Development of a Grid-Independent Geos-Chem Chemical Transport Model (v9-02) as an Atmospheric Chemistry Module for Earth System ModelsThe GEOS-Chem global chemical transport model (CTM), used by a large atmospheric chemistry research community, has been re-engineered to also serve as an atmospheric chemistry module for Earth system models (ESMs). This was done using an Earth System Modeling Framework (ESMF) interface that operates independently of the GEOSChem scientific code, permitting the exact same GEOSChem code to be used as an ESM module or as a standalone CTM. In this manner, the continual stream of updates contributed by the CTM user community is automatically passed on to the ESM module, which remains state of science and referenced to the latest version of the standard GEOS-Chem CTM. A major step in this re-engineering was to make GEOS-Chem grid independent, i.e., capable of using any geophysical grid specified at run time. GEOS-Chem data sockets were also created for communication between modules and with external ESM code. The grid-independent, ESMF-compatible GEOS-Chem is now the standard version of the GEOS-Chem CTM. It has been implemented as an atmospheric chemistry module into the NASA GEOS- 5 ESM. The coupled GEOS-5-GEOS-Chem system was tested for scalability and performance with a tropospheric oxidant-aerosol simulation (120 coupled species, 66 transported tracers) using 48-240 cores and message-passing interface (MPI) distributed-memory parallelization. Numerical experiments demonstrate that the GEOS-Chem chemistry module scales efficiently for the number of cores tested, with no degradation as the number of cores increases. Although inclusion of atmospheric chemistry in ESMs is computationally expensive, the excellent scalability of the chemistry module means that the relative cost goes down with increasing number of cores in a massively parallel environment.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Long, M. S. (Harvard Univ. Cambridge, MA, United States)
Yantosca, R. (Harvard Univ. Cambridge, MA, United States)
Nielsen, J. E (Science Systems and Applications, Inc. Lanham, MD, United States)
Keller, C. A. (Universities Space Research Association Greenbelt, MD, United States)
Da Silva, A. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Sulprizio, M. P. (Harvard Univ. Cambridge, MA, United States)
Pawson, S. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Jacob, D. J. (Harvard Univ. Cambridge, MA, United States)
Date Acquired
January 31, 2017
Publication Date
March 13, 2015
Publication Information
Publication: Geoscientific Model Development
Volume: 8
Issue: 3
Subject Category
Computer Programming and Software
Geosciences (General)
Report/Patent Number
Funding Number(s)
Distribution Limits