Ozone in ERA-40: 1991-1996

Ozone in ERA-40: 1991-1996
Date Published
ERA-40 Project Report Series
Document Number
A. Dethof
Event Series/Collection
ERA Report
Abstract This paper takes a first look at the quality of the ozone analysis in the ERA-40 project between 1991 and 1996. In the ERA-40 analysis system TOMS and SBUV data from various platforms are assimilated between 1991 and 1996. The analyzed total column ozone field is generally good and has a realistic seasonal cycle. The large scale structures of the analyzed stratospheric ozone are also reasonable. However, there are problems with the vertical structure of the analyzed ozone fields, particularly in the troposphere and polar regions. These problems come from the background errors for ozone which are used in ERA-40 until October 1996 and which have significant anti-correlations between the stratosphere and the troposphere.