On the Validation of the Nimbus 7 LIMS Version 6 Stratospheric Ozone

The Nimbus 7 LIMS experiment obtained daily distributions of ozone from late October 1978 through late May 1979 and with good vertical resolution and spatial sampling along its orbital tangent tracks. The historic LIMS Version 5 (V5) dataset was archived in 1982. Studies of those data revealed detailed information about the roles of chemistry and transport on the distribution of ozone in the stratosphere for the latitudes of 64S to 84N. Although its profiles were of good quality throughout most of the stratosphere, both the simulation and validation studies indicated that the accuracy of the V5 ozone became less good below about the 30-hPa level at low latitudes and below the 50-hPa level at middle and high latitudes, especially during polar winter. A LIMS Version 6 (V6) algorithm was developed some years later, in part, to improve on the quality of the ozone profiles in the lower stratosphere. That V6 profile dataset was created in 2001 and archived in 2002. In this paper we present comparisons of the LIMS V6 ozone with the SBUV Version 8 (V8) data, with the preliminary SAGE I Version 6 data, and with balloon ECC ozonesonde soundings from several stations. The findings indicate significant improvements in accuracy for LIMS V6 ozone in the lower stratosphere and better vertical and horizontal sampling for the changes in ozone at polar latitudes and throughout the Arctic winter period. This revised ozone dataset should provide for a better assessment of the effects of chemistry and transport on polar and middle latitude ozone for the Northern Hemisphere winter of 1978-79, when the loss of ozone due to reactive chlorine from heterogeneous processes was not as significant as it is today.