A 5-YEAR EVALUATION OF THE REPRESENTATIVENESS OF THE TROPOSPHERIC OZONE RESIDUAL AT NONCLIMATOLOGICAL PERIODS

Daily values, monthly averages, and seasonal averages of the troposphe ric ozone residual (TOR) were estimated using the Total Ozone Mapping Spectrometer (TOMS) and the Solar Backscattered Ultraviolet (SEW) data for the five-year period 1985-1989. Comparisons were made at these va rious timescales between TOR and tropospheric ozone using data from ei ght ozonesonde stations within the region 50 degrees N to 50 degrees S and between normalized departures of the TOR and surface ozone data a veraged over four 5 degrees latitude by 5 degrees longitude squares wi thin the eastern United States. These comparisons were accomplished to determine the usefulness of the TOR to represent tropospheric ozone a t nonclimatological periods. The results indicated that the annual cyc le of the TOR determined using monthly and seasonally averaged values provides a realistic depiction of the annual cycle of tropospheric ozo ne in the northern hemisphere; that is, approximately a 2% mean error and an 81% correlation. However, in a limited number of comparisons (H ilo and Natal), the annual cycle of the TOR represented the annual cyc le of tropospheric ozone at tropical latitudes poorly; that is, approx imately a 38% mean error and a 59% correlation.