On the feasibility of using the tropospheric ozone residual for nonclimatological studies on a quasi‐global scale

The tropospheric ozone residual (TOR) was estimated using total ozone mapping spectrometer (TOMS), Stratospheric Aerosol and Gas Experiment (SAGE), and solar backscatter ultraviolet (SBUV) data for nonclimatological periods (i.e., daily values, weekly averages, and monthly averages). The TOR is the difference between the total ozone from TOMS and the stratospheric ozone estimated using either SAGE or SBUV ozone data and the National Meteorological Center tropopause pressure data. Comparison of the TOMS/SAGE TOR with ozonesonde data and with area‐averaged surface ozone data for nonclimatological periods was very poor. The month‐to‐month variations of the TOMS/SBUV TOR, on the other hand, compared very well with the month‐to‐month variations of the area‐averaged surface ozone concentrations, and the day‐to‐day variations of the tropospheric ozone using ozonesonde data from five stations compared reasonably well with the day‐to‐day variations of the TOR. However, the RMS difference between the TOMS/SBUV TOR and the tropospheric ozone from ozonesonde data was about 14.4 Dobson units (DU) and the mean difference about 8 DU, though the mean difference was about 1.5 DU at Boulder, Colorado.