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GEOS–Chem Wiki

GEOS-Chem Community Mission: to advance understanding of human and natural influences on the environment through a comprehensive, state-of-the-science, readily accessible global model of atmospheric composition. The GEOS–Chem model is a global 3-D model of atmospheric composition driven by assimilated meteorological observations from the Goddard Earth Observing System (GEOS) of the NASA Global Modeling and Assimilation Office. It is applied by research groups around the world to a wide range of atmospheric composition problems, Central management and support of the model is provided by the Atmospheric Chemistry Modeling Group at Harvard University.

GEOS-Chem overview
Past releases	Current release: GEOS-Chem 12.9.3	Future releases

News

• 11 Dec 2020: A GEOS-Chem Google Scholar page is now available! Click 'Follow' to be notified of new publications. Contact Gongda Lu with issues or questions.
• 06 Aug 2020: GEOS-Chem 12.9.3 is now available!
• 30 May 2020 Read the GEOS-Chem Newsletter, Spring 2020 Edition!
• 02 Apr 2020: The GEOS-Chem Youtube Channel has 100+ subscribers and a new URL: https://youtube.com/c/geoschem!
• 03 Feb 2020: View our GEOS-Chem "dry-run" tutorial at our GEOS-Chem Youtube channel!
• 17 Sep 2019: NASA/GMAO is now producing GEOS chemical forecasts (GEOS-CF) using GEOS-Chem coupled to the NASA/GEOS ESM!
• 14 Jun 2019: We have overhauled the GEOS-Chem wiki to make content easier to understand. If you miss the old front page, it can still be viewed HERE.

For access to all past GEOS-Chem newsletters, visit this page.

Documentation

GEOS-Chem manuals and tutorials

The table below lists the various manual pages for GEOS-Chem and its related software packages.

Item	Description	Documentation is located at:
GEOS-Chem Classic	GEOS-Chem single-node implementation (using 1-64 computational cores)	Getting Started with GEOS-Chem (wiki page)
GCHP	GEOS-Chem multi-node "high performance" implementation (using 100's - 1000's of computational cores)	gchp.readthedocs.io
GEOS-Chem on the cloud	Instructions for running GEOS-Chem on the Amazon Web Services EC2 cloud-computing platform	cloud.geos-chem.org
WRF-GC	GEOS-Chem coupled to the WRF GCM	wrf.geos-chem.org
HEMCO	The Harmonized Emissions Component	hemco.readthedocs.io
GCPy	The GEOS-Chem Python Toolkit	gcpy.readthedocs.io
GEOS-Chem Adjoint	The GEOS-Chem adjoint model (NOTE: maintained separately from GEOS-Chem)	GEOS-Chem Adjoint (wiki page)
GEOS-Chem Videos	Tutorial videos for GEOS-Chem, GCHP, HEMCO, GCPy, and related topics	youtube.com/c/geos-chem
GEOS-Chem Guides	Short manuals giving a deeper dive into various GEOS-Chem topics (such as compilers, netCDF, diagnostics, etc.)	GEOS-Chem Guides (wiki page)

General information about GEOS-Chem

The table below lists where you can find general information about GEOS-Chem

Item	Description	Documentation is located at:
Welcome Letter	A welcome letter for new users of GEOS-Chem	GEOS-Chem welcome letter for new users (wiki page)
GEOS-Chem Overview	A welcome letter for new users of GEOS-Chem	GEOS-Chem overview (wiki page)
GEOS-Chem Versions	A list of GEOS-Chem versions	GEOS-Chem versions (wiki page)
GEOS-Chem Species List	Information about species used in the GEOS-Chem chemistry mechanisms	Guide to species in GEOS-Chem (wiki page)
Requesting Suppport	A guide to creating GEOS-Chem support requests using the Github issue trackers	Submitting GEOS-Chem support requests (wiki page)
Submitting code or data	Guidelines for submitting new science updates or new data sources for inclusion into GEOS-Chem	Submitting updates for inclusion in GEOS-Chem (wiki page)