CAM-Chem results for a subset of the globe and a range of dates can be downloaded from this page. Output is provided every 6 hours. Each request is provided as a single netcdf file. We strongly recommend that you download a single day for your region to check the file size and then request a range of dates that will result in a manageable file size. Requests for time spans longer than 32 days are not supported. Questions about CAM-Chem and requests for additional dates can be addressed to Rebecca Buchholz (buchholz at ucar . edu).
Direct data download is also avalailable from the NCAR Research Data Archive; registration is required. If you are retrieving the entire globe, please register and download directly from the NCAR RDA instead.
The 'date' and 'datesec' variables contain the date and time of the CAM-Chem output. To verify the date of the downloaded files, please use 'ncdump -v date'. The program ncview does not properly interpret the 'time' variable and calculates an erroneous date.
CAM-Chem results are available for January 1, 2001 to December 31, 2020.
Further details are available at the Wiki page
CESM2.1: CAM-Chem as Boundary Conditions.
For more recent dates, consider using
If you require further information, please contact Rebecca Buchholz (buchholz at ucar . edu).
To cite the data directly, please use:
Buchholz, R. R., Emmons, L. K., Tilmes, S., & The CESM2 Development Team, (2019). CESM2.1/CAM-chem Instantaneous Output for Boundary Conditions. UCAR/NCAR - Atmospheric Chemistry Observations and Modeling Laboratory. Subset used† XXX, Accessed* dd mmm yyyy, https://doi.org/10.5065/NMP7-EP60.
†Please fill in the "subset used" with region and/or date of the subset you used (e.g. Lat: -10 to 10, Lon: 100 to 150, September 2015 - February 2016).
*Please fill in the "Accessed" date with the day, month, and year that you last accessed the data (e.g. - 5 Aug 2011).
We suggest to also cite the following paper that discusses the new configuration of CESM2/CAM-chem and assesses chemical species, including using output from this boundary condition simulation.
Emmons, L. K., Schwantes, R. H., Orlando, J. J., Tyndall, G., Kinnison, D., Lamarque, J.‐F., et al., (2020). The Chemistry Mechanism in the Community Earth System Model version 2 (CESM2). Journal of Advances in Modeling Earth Systems, 12, e2019MS001882, https://doi.org/10.1029/2019MS001882.