ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-6-5163-2006 Differences between ground Dobson, Brewer and satellite TOMS-8, GOME-WFDOAS total ozone observations at Hradec Kralove, Czech Vanicek K. 1 Solar and Ozone Observatory, Czech Hydrometeorological Institute, Hvezdarna 456, 50008 Hradec Kralove, Czech Republic 14 11 2006 6 12 5163 5171 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/6/5163/2006/acp-6-5163-2006.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/6/5163/2006/acp-6-5163-2006.pdf

This paper presents key results achieved by an analysis of the relation between high-quality simultaneous Dobson, Brewer ground and TOMS-V8, GOME-WFDOAS satellite total ozone observations for Hradec Kralove, Czech Republic. Statistically significant seasonal differences with maxima up to 4% of monthly averages have been found between Dobson and Brewer measurements during the winter/spring months. These differences can influence estimations of ozone trends if combined data series are used after replacing a Dobson instrument by a Brewer spectrophotometer. The differences can be attributed mostly to the influence of temperature on ozone absorption coefficients and to total sulphur dioxide. Similar seasonal differences exist between Dobson, GOME and Brewer, TOMS data sets at Hradec Kralove while Dobson versus TOMS and Brewer versus GOME observations fit well with each other within the instrumental accuracy of spectrophotometers. The above findings are supposed to be relevant to other mid and high latitude stations and they have been confirmed by several independent analyses. The conclusions should be considered by data users because the differences between particular ground and satellite data sets can influence validation of satellite ozone observing systems and analyses of recovery of the ozone layer in mid and high latitudes, among others.

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