Stratospheric analyses provided by the UK Meteorological Office

Since late 1978, the UK Met Office (UKMO) has processed accurate radiance measurements of the stratosphere from a set of three radiometers (SSU, MSU and HIRS) flown on satellites in the TIROS series. The radiometers scan both sides of the sub-satellite track giving almost global coverage. UKMO uses its own retrieval algorithm to derive thicknesses from radiances. The retrieval is a linear, physical-statistical method which utilizes a reference set of temperature profiles as a priori data. Thicknesses are added to a contemporaneous field of geopotential height at 100HPa to give geopotential heights at standard pressure levels in the stratosphere up to 1HPa. Global synoptic fields for 12 GMT are produced every day on a regular latitude-longitude grid by linear interpolation in space and time. This paper describes the retrieval method and objective analysis in detail. It outlines the availability of data in the 12-year archive, and summarizes the main findings of several studies on data quality. Finally, it tells prospective users how to get the data, and what checks they should make before trying to interpret them.