The GSFC TOMS CCD L3 5x5deg Monthly Tropospheric Column Ozone product (TrCO3_Monthly_TOMS) contains tropospheric column ozone amounts averaged by month from 1979 to 2005. Total column measurements are obtained from the Total Ozone Monitoring Sensor (TOMS) on the Nimbus-7 (1979-1993) and the Earth Probe (1996-2005) satellites. Tropospheric column ozone (TCO) is determined using the convective-cloud differential (CCD) method and is limited to the tropical region. In this method stratospheric column ozone (SCO) is estimated from the TOMS ozone observations over high altitude deep convective clouds and then subtracted from TOMS total column ozone.

The data are stored in an ASCII text file. Data are averaged monthly at 5 degree x 5 degree resolution between -30 degrees and +30 degrees. The single data file size is 2.5 MB.