A complementary analysis for SAGE II data profiles

We present a screened and gridded SAGE II data set, as a complement to the profile data available for the 19 years of records from November 1984 through December 2003. The data screening method is described, and differences between screened and unscreened data are presented. Extensive changes occur in the water vapor data set, which has excessive values in many regions without the screening. Screened NO2 values are larger in the middle stratosphere, for the zonal average by up to 10-15%, and reduced in the lower stratosphere zonally by up to 15-30%, while zonal average ozone values are as much as 20-30% larger in the lower stratosphere and upper troposphere. Many of these changes are due to interference effects from aerosols and clouds, but additional bad data points, isolated by visual inspection, occur for no obvious reason. The screening procedures also remove spurious trends. This data set is available via CD-ROM.