Abstract
Improvements are provided here for the ozone reference model which is to be incorporated in the COSPAR International Reference Atmosphere (CIRA). The ozone reference model will provide considerable information on the global ozone distribution, including ozone vertical structure as a function of month and latitude from approximately 25 to 90 km, combining data from five recent satellite experiments (Nimbus 7 LIMS, Nimbus 7 SBUV, AE-2 SAGE, Solar Mesosphere Explorer (SME) UVS, and SME IR). The improved models described here use reprocessed AE-2 SAGE data (sunset) and extend the use of SAGE data from 1981 to the period 1981–1983. It is found that these SAGE data agree at all latitudes and months with the ozone reference model within 15 percent and result in modifications in the reference model of less than 4 percent. In the mesosphere, a model of nighttime conditions (= 10 p.m.) has been added using Nimbus 7 LIMS data between pressures of 0.5 mb to 0.05 mb (= 54 to 70 km). Minimum nightside ozone mixing ratios occur at about 0.2 mb (= 61 km). The ratio of nightside LIMS data to dayside (= 3 p.m.) SME data gives diurnal variations as large as a factor of 6 at the highest levels. At 0.1 mb (= 66 km), the night-day diurnal variation can exceed 3 and maximizes during solstice periods near 45 degrees in the summer hemisphere and near the Equator during equinoctial periods. This may largely result from the dayside ozone being more strongly photodissociated by the more directly incident summer Sun at mid latitudes and the equinoctial Sun at the Equator. Comparisons are shown between the ozone reference model and various non-satellite measurements at different levels in the middle atmosphere.
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