Intercomparison between ground based and TOMS/EP satellite southern hemisphere ozone data. New results

We present new results of the intercomparison between ozone total column data registered at the Southern Hemisphere with the World Meteorological Organization ground stations of the Southern Cone Ozone Project placed in Uruguay, Argentina and the Antarctic continent, with the Total Ozone Mapping Spectrometer (TOMS) instrument on board the Earth Probe satellite and with the Global Ozone Monitoring Experiment (GOME) instrument on board the Earth Remote Sensing (ERS-2) satellite. At least for the region and period considered, GOME/ERS-2 ozone data gives lower mean systematic relative difference (-1.4 3.2) % than TOMS/EP (4.8 2.7) % with respect to ground spectroradiometers. An analysis of possible causes for the large systematic difference in this last case has been considered: differences with respect to a similar instrument placed in another satellite both measuring the same geophysical variable at different orbits; difference with respect to GOME/ERS-2 satellite measurements in the entire region; possible influence on TOMS data of the difference in reflectivity at the high latitude ice (snow)-sea boundary. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.