Two-dimensional advection model for interpolation of ozone satellite data

A 2D advection model is developed at KNMI to advect and assimilate total ozone using a windfield at a single pressure level. The Advection Model KNMI with a resolution of 110 × 110 km² describes the transport of total ozone, considering ozone as a passive tracer, using a simple linear advection equation. Ozone data measured by the TOVS instrument on the NOAA polar satellites and windfields from the MARS archives of ECMWF are used. By means of the AMK model the TOVS total ozone maps, which are hampered by missing data, can be replaced by global total ozone maps at a given time without gaps in the data. The windfield that must be used for transporting total ozone is, however, not obvious. In this paper it is shown that the 200 hPa windfield is the optimal windfield to choose for advecting total ozone. Ground-based data are often used for validation of satellite measurements. By advection of the satellite total ozone data to the same location and time as the ground-based measurements, validation can in principle be improved. In this paper, Brewer total ozone measured at De Bilt, TOVS total ozone and assimilated TOVS total ozone, for the pixel closest to De Bilt, are compared and the results are discussed.