Comparison of ground-based Dobson and satellite EP-TOMS total ozone measurements over Vernadsky station, Antarctica, 1996-2005

Total ozone content derived from version 8 of the Earth Probe Total Ozone Mapping Spectrometer (EP-TOMS) satellite data was compared with that from ground-based data obtained with the Dobson spectrophotometer no. 031 at the Ukrainian Antarctic Vernadsky station. The period of comparison is 1996-2005. The statistics for cloudy and clear sky observations are presented separately, in order to assess the influence of cloudiness on the difference between the satellite and ground-based measurements. The main findings obtained from the TOMS-Dobson difference analysis were: (i) a significant disagreement between clear and cloudy sky differences of about 9%, which is almost the same value as in version 7; and (ii) the difference for all data equals -2.0% (2625 days), whereas in cloudless and cloudy conditions the difference is 4.1% (137 days) and -4.5% (1048 days), respectively. We conclude that the TOMS (Dobson) measurements are mostly responsible for the data disagreement in clear (cloudy) sky conditions.