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GEOS–Chem Wiki

The 9th International GEOS-Chem Meeting (IGC9) will be held at Harvard from May 6-9, 2019. 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. This wiki is meant to facilitate communication between GEOS-Chem users and developers. If this is your first time here, check out the features page. If you would like to contribute to the wiki, please register as a user by clicking create account at the top right corner of this page. New information is continually being added to the wiki, so please check back here often, or even better, subscribe to the recent changes' RSS feed: you will not miss a discussion!

Past releases

Current release: GEOS-Chem 12.3.1

Future releases

General information about GEOS-Chem
Featured links
To get started with GEOS-Chem, please see our manuals: GEOS-Chem User's Guide and Getting Started With GCHP
Learn how you can run GEOS-Chem on the Amazon Web Services cloud computing platform!
Learn how you can use GEOS-Chem coupled with WRF!
For assistance with GEOS-Chem, please see: Submitting GEOS-Chem support requests
Introduction to GEOS-Chem and the International GEOS-Chem User Community
Overview of GEOS-Chem and its user community GEOS-Chem welcome letter for new users GEOS-Chem People & Projects GEOS-Chem Support Team GEOS-Chem newsletters GEOS-Chem versions Narrative description of GEOS-Chem GEOS-Chem public license and list of developers List of GEOS-Chem publications Recommendations for offering co-authorships to GEOS-Chem developers GEOS-Chem Search Engines	GEOS-Chem Steering Committee GEOS-Chem model development priorities GEOS-Chem Working Groups Adjoint Model and Data Assimilation Working Group Aerosols Working Group Carbon Cycle Working Group Chemistry-Ecosystem-Climate Working Group GEOS-Chem High Performance Working Group Hg and POPs Working Group Chemistry Working Group Emissions and Deposition Working Group Transport Working Group Stratospheric Working Group GEOS-Chem Nested Model
Getting started with GEOS-Chem
Basic information about getting set up with GEOS-Chem GEOS-Chem User's Guide Using GEOS-Chem on the Amazon Web Services Cloud GCHP User's Guide Using WRF-GC: GEOS-Chem interfaced with WRF Frequently asked questions about GEOS-Chem	Minimum system requirements for GEOS-Chem Downloading GEOS-Chem source code and data Creating GEOS-Chem run directories

GEOS-Chem Code Developers' Forums
Coding	Meteorology Fields
GEOS-Chem coding and debugging GEOS-Chem coding style guide List of GEOS-Chem bugs and in which version they were resolved Currently unresolved issues in GEOS-Chem Known GEOS-Chem issues caused by compiler bugs Common GEOS-Chem error messages Tips on how to debug GEOS-Chem effectively Debugging with the GEOS-Chem unit tester Performing Difference Tests with GEOS-Chem Submitting GEOS-Chem support requests Working with netCDF data files GEOS-Chem performance Speeding up GEOS-Chem Profiling GEOS-Chem Parallelizing GEOS-Chem with the OpenMP directives Passing array arguments efficiently in GEOS-Chem Floating point math issues	GEOS-Chem horizontal grids and vertical grids Overview of GMAO met data products Version history of GMAO met data products Available met data for nested grid simulations List of reprocessed met fields GMAO MERRA-2 List of MERRA-2 met fields used by GEOS-Chem Implementing MERRA-2 into GEOS-Chem GMAO GEOS-FP List of GEOS-FP met fields used by GEOS-Chem Implementing GEOS-FP into GEOS-Chem
Emissions	Chemistry
HEMCO emissions component HEMCO data directories The HEMCO User's Guide HEMCO examples HEMCO versions Emissions categories Grid-independent emissions Aerosol emissions Aircraft emissions Anthropogenic emissions Scale factors for anthropogenic emissions Biofuel emissions Biogenic emissions Biomass burning emissions Lightning NOx emissions Ship emissions Soil NOx emissions Volcanic emissions Historical and future emissions	GEOS-Chem chemistry mechanisms Stratopsheric chemistry options Specialty simulations Photolysis mechanisms used in GEOS-Chem Species in GEOS-Chem GEOS-Chem species database Physical properties of GEOS-Chem species GEOS-Chem species units Species indexing in GEOS-Chem Adding species to GEOS-Chem Adding passive species to GEOS-Chem Other resources FlexChem Chemistry Issues Centralized chemistry time step Process Analysis Diagnostics Linking GEOS-Chem to CMAQ Coupling GEOS-Chem with RRTMG DSMACC chemical box model
Dynamics	Deposition
Advection scheme TPCORE Boundary layer mixing Cloud convection Dynamic tropopause	Dry deposition Leaf area indices in GEOS-Chem Olson land map Wet deposition
Aerosols	Benchmarking and Evaluation
Aerosol-only simulation Aerosol optical properties Aerosol thermodynamical equilibrium Carbonaceous aerosols Mineral dust aerosols Secondary organic aerosols Sea salt aerosols Sulfate aerosols Aerosol Microphysics APM TOMAS	General info about GEOS-Chem benchmark simulations List of GEOS-Chem 1-year benchmark simulations Mean OH concentration 1-month benchmark timing results GEOS-Chem participation in community intercomparisons Satellite Instrument Specifications Table
Nested grid simulations	Diagnostics
GEOS-Chem nested grid simulations Setting up GEOS-Chem nested grid simulations Available met data for nested grid simulations Protocol for nested-grid data downloads Steps to setup new nested domains GEOS-Chem nested model publications	Available diagnostics in GEOS-Chem NetCDF format Binary punch (aka bpch) format ObsPack diagnostic Planeflight diagnostic Archiving diagnostics from HEMCO to netCDF files Diagnostic time step Additional diagnostics
Related projects	Other resources
GEOS-Chem HP GEOS-Chem Adjoint Coupling GEOS-Chem with other models FlexAOD ATom Related GEOS-Chem Projects	GEOS-Chem publications page on ResearcherID Presentations from the GCA1 meeting (2018) Presentations from the IGC8 Meeting (2017) Presentations from the IGC7 meeting (2015) Presentations from the IGC6 meeting (2013)

Reference Section
IDL	GAMAP
Using IDL (Harris Geospatial Solutions site) Structures in IDL Pointers in IDL Overview of Mathematics in IDL IDL Astronomy User's Library JHU/APL/S1R IDL routines page Craig Markwardt's IDL library Reading binary files in IDL	GAMAP web page GAMAP on-line users' guide GAMAP bugs and fixes GAMAP tips and tricks General GAMAP usage TVMAP cheat sheet File I/O with GAMAP Working with timeseries output in GAMAP Color and graphics with GAMAP Loading Color Tables in GAMAP v2.12 Working with color in IDL by Chris Holmes Regridding with GAMAP Date and time computations with GAMAP Text manipulation with GAMAP
Fortran	Perl
Fortran tutorials GNU Fortran compiler Intel Fortran Compiler	Perl.com Beginning Perl by Simon Cozens (free online book) Perl in 20 pages MediaWiki User's Guide Comprehensive Perl Archive Network (CPAN.org)
R	Python
The R project for statistical computing The R journal R by example Using R to analyze GEOS-Chem data	Python code for GEOS-Chem Python.org: Main site for all things Python Python.org Tutorial PythonWiki.org: List of tutorials and resources Google's Python tutorial
NCAR Command Language (NCL)	Wiki documentation
NCL main page NCL applications NCL documentation Sign up for NCL-Talk email list NCL4GC: NCL tools for GEOS-Chem	Features of the GEOS-Chem public wiki Customizing your GEOS-Chem Wiki Settings Sandbox MediaWiki FAQ MediaWiki User's Guide Examples of Wiki markup text One-page editing reference card Configuration Settings list MediaWiki release mailing list