Nimbus-7 Total Ozone Observations of Western North Pacific Tropical Cyclones

Abstract

The Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) was used to map the distribution of total ozone around western North Pacific tropical cyclones from 1979 to 1982. The strong correlation between total ozone distribution and tropopause height found in the subtropical and midlatitudes made it possible for TOMS to monitor the propagation of upper-tropospheric waves and the mutual adjustment between these waves and tropical cyclones during their interaction. Changes in these total ozone patterns reflect the three-dimensional upper-tropospheric transport processes that are involved in tropical cyclone intensity and intensity and motion changes. The total ozone distributions indicate that 1) the mean upper-tropospheric circulations associated with western North Pacific and Atlantic tropical cyclones are similar; 2) more intense tropical cyclones have higher tropopauses around their centers; 3) more intense tropical cyclones have higher tropopauses on the anticyclonic-shear side of their outflow jets, which indicate that the more intense tropical cyclones have stronger outflow channels than less intense systems; 4) tropical cyclones that intensify (do not intensify) are within 10° (15°) latitude of weak (strong) upper-tropospheric troughs that are moderately rich (very rich) in total ozone; and 5) tropical cyclones turn to the left (right) when they move within approximately 15° latitude downstream of an ozone-poor (ozone-rich) upper-tropospheric ridge (trough).