Seven years of TOMS total ozone data are currently available. Recently a new ozone retrieval algorithm based on improved ozone absorption cross section was implemented that has introduced 6--7% discontinuity in the archived data sets at the end of the 5th year of instrument operation. Until all data are reprocessed with the new algorithm users can use a table of correction factors given in this paper to make the data set internally consistent.

This paper also presents a comparison of TOMS results with Amundsen Scott Dobson station. Though the agreement in most years is good, in 1983--84 the Dobson station reported unusually high values of ozone while TOMS was the very low ozone values associated with the Antarctica ozone hole.