README for GMImetVsNonlinSZA.PL_T_AIRDENS.zmeans. files

These files contain output from the GEOSCCM SAGEIII replay simulation with GMI chemistry (simulation I32_S3_v2). 

Each file includes model output for pressure (PL), temperature (T), and air density (Airdens) as a function of latitude and signed solar zenith angle (SZA). Please note that SZA in these files, unlike the SZA in the NO2column and NO column files, is signed (positive or negative) to distinguish morning versus afternoon. The model output was first interpolated to the altitudes and SZA values given in the altitude and SZA dimensions, respecitively, and then zonally averaged. Since not all SZA values are present at every latitude and month, -9999 is used to indicate missing values. Files are provided for each year and month for the 2017-2021 period. In addition to the files for specific years and months (e.g. GMImetVsNonlinSZA.PL_T_AIRDENS.zmeans.201805.nc for May 2018), we also provide a monthly climatology created by averaging the values for each month over the years 2017-2020. These files have .clim. in the file name.

The format of these files is designed to correspond to that of the scaling factor files (GMIscaleFactorsVsNonlinSZA.zmeans.*) to facilitate unit conversion and the calculation of column values from the concentrations of O3, NO2, NO, or NO3 found in those files.