The use of direct readout, high resolution TOVS data in short and medium range weather predictions

Abstract Since 1983, the UK Meteorological Office has been receiving the direct readout transmissions of TIROS-N Operational Vertical Sounder (TOVS) data from the NOAA satellites and routinely deriving high resolution temperature and humidity profiles for the North Atlantic/European area. These profiles are used by forecasters in the production of subjective analyses and are also used in the operational coarse- and fine-mesh numerical analysis schemes. The process of deriving these profiles using locally derived regression coefficients is described with a brief account of a new cloud clearing process now being tested. Characteristics of profiles and 1000-500MB thickness fields derived from the retrieval data when compared with conventional profiles and fields, which have been noted over a two year period, are described. An example of a comparison of profiles from TOVS data with collocated radiosonde profiles is also shown. Finally, work on new retrieval methods is outlined.