Second update for all 2020 GMI model output data at NDACC

Mea culpa, mea culpa! This summer we discovered there was another bug hiding in our 2020 simulation. If you happened to look at tropospheric ozone from May-Dec you might have wondered how the world got so polluted, especially with reduced travel during the pandemic. This affected all 2020 files. Please replace any 2020 file you currently have with a new one.

The new Dobson, Sonde, and Lidar files have 'MR2V4' in their name, while the current FTIR files are ‘MR2V3’. All files can be downloaded via anonymous ftp from


Please see the March 2021 news article for additional information on the GMI CTM model version used for the MR2V3 and MR2V4 files. As always, please contact Susan Strahan ( for additional model support or questions.