Equatorial ozone profiles from the ground to 52 km during the southern hemisphere autumn

Abstract

We report the results of an ozone measurement campaign conducted at Natal, Brazil (5.9°S, 35.2°W) from March 25 to April 15, 1985. Seven profiles were obtained during this period, using ROCOZ‐A and electrochemical concentration cell ozonesondes, standard U.S. meteorological radiosondes, and Super‐Loki datasondes. Complete profiles of ozone, pressure, and temperature were obtained from the ground to 52 km, and all of the profiles correspond with site overpasses by ozone instruments on NASA and National Oceanic and Atmospheric Administration satellites. The profiles from this measurement series show reasonable agreement with established satellite climatologies. Stratospheric ozone variability was 2% or less during the 3 weeks of the measurement campaign, with stratospheric temperature and pressure variabilities half that amount. Low variability at a single location for this period implies comparable uniformity for ozone profiles over a large area around the measurement site. This condition at Natal removes the requirement of exact concurrence between satellite and local ozone measurements, allowing comparisons of larger sets of profiles and improving the precision of the intercomparisons. Regional ozone stability also allows an overall intercomparison of ozone measurements among the four satellites without the need for zonal mean averages. The auxiliary pressure and temperature profiles presented here allow the use of this data set as a transfer standard between satellite instruments with different fundamental ozone measurements. Finally, the low ozone variability in the stratosphere at Natal during this measurement series should provide an opportunity for high‐quality intercomparisons of measured and modeled ozone concentrations in the equatorial stratosphere and lower mesosphere as well as a consistency check among satellite ozone measurements.