Preprocessing of total ozone content as an input parameter to UV Index forecast calculations

In this paper we present a simple method to correct satellite based measurements of the total ozone content of the atmosphere (TOC) to be valid without any spatial restriction. The method delivers also a global data set of TOC, which can be used for the operational forecast of the erythemally effective ultraviolet (UV) irradiance, in the form of the UV Index. The method is based on TOC measurements made by NASA's Earth Probe TOMS. Corrections are applied to gain TOC values that are in good agreement with ground‐based measurements. The algorithm of Kriging is applied for interpolation and for filling up gaps in grids. This method is validated by a comparison to measurements of TOC from the ground made at 5 observatories between 50°N and 30°S and between 285 m and 3106 m asl. From an auto‐correlation analysis with different time lags it is shown that the assumption of TOC persistency of a 2‐day period guarantees a quality that is convenient with the requirements of UV Index forecast procedures. For a wide zonal range covering 34% of the Earth's surface only a small improvement can be made by more sophisticated TOC forecast models, since uncertainties of our scheme are already on the order of the intrinsic uncertainties of the measuring devices.