Frequently asked questions about GEOS-Chem
On this page we shall answer some commonly asked questions about GEOS-Chem.
- 1 Basic information about GEOS-Chem
- 2 Where can I get restart files for GEOS-Chem?
- 3 Running GEOS-Chem
- 4 GEOS-Chem errors
Basic information about GEOS-Chem
For new users
- I am a GEOS-Chem new user. What is expected of me?
- On what types of machines can I run GEOS-Chem?
- Can I use GEOS-Chem on cloud-computing platforms?
- What types of simulations can I run with GEOS-Chem?
- What is the horizontal resolution and vertical resolution of GEOS-Chem?
- Which meteorological data fields can be used by GEOS-Chem?
- To whom can I direct GEOS-Chem-related questions?
- What does the GEOS-Chem Steering Committee do?
- What do the GEOS-Chem Working Groups do?
- What does the GEOS-Chem Support Team do?
- I see that there are several GEOS-Chem email lists. How can I subscribe?
Where can I find information about ...
- the available chemical mechanisms in GEOS-Chem?
- the bromine chemistry mechanism in GEOS-Chem?
- the KPP chemical solver?
- the Linoz stratospheric ozone chemistry scheme?
- the stratospheric chemistry mechanism?
- Other chemistry simulations such as CO2, CH4, Hg, etc.?
- emissions options in GEOS-Chem?
- the advection scheme in GEOS-Chem?
- the boundary layer mixing schemes in GEOS-Chem?
- the cloud convection schemes in GEOS-Chem?
- The Dry deposition and Wet deposition schemes in GEOS-Chem?
- GEOS-Chem nested grid simulations?
- How do I download the GEOS-Chem source code and run directories?
- What should I do when I encounter an error while running GEOS-Chem?
- Do you have any information about GEOS-Chem performance and GEOS-Chem scalability?
- Where can I learn more about the GEOS-Chem Makefiles?
- Is there a comprehensive list of GEOS-Chem bugs and how they were fixed?
- I am new to programming. Do you have any online resources or tutorials?
- Are there any numerical issues that I should be aware of?
- Do you have any tools that would help me debug GEOS-Chem more efficiently?
- How can I tell if a variable has to be declared with !$OMP PRIVATE or !$OMP SHARED?
- How many CPUs may I use for my GEOS-Chem simulation?
- Why is GEOS-Chem not using all the CPUs that I requested?
High-Performance GEOS-Chem (GCHP)
Please see the GCHP main wiki page for information about GCHP.
Where can I get restart files for GEOS-Chem?
For instructions on how to obtain a set of sample restart files that you can use to spin up your own simulations, please see the Restart Files section of our GEOS-Chem basics wiki page.
Please see our Running GEOS-Chem wiki page.
How long does GEOS-Chem take to run?
It depends on your particular computing environment. We have posted several timing results from GEOS-Chem 7-day time test simulations.
GEOS-Chem seems to be running too slowly. What can I do?
You should be aware of several compile-time options that will slow down GEOS-Chem. Use these options only for debugging, but not in your production runs.
If you are archiving many diagnostic quantities are a high temporal resolution (e.g. every hour), then this will increase the run time of your simulation. You can try saving out less diagnostic quantities, or archiving at a lower temporal resolution (e.g. every day).