Delineation of Precipitation Areas Using Meteosat Infrared and Visible Data in the Region of the United Kingdom

Abstract

The relationship between precipitation and infrared and visible satellite data is investigated in the vicinity of the United Kingdom. The investigation uses histograms of Meteosat data, built up from many half-hourly fields, which represent the frequency distribution of the pixels as a function of temperature and brightness. Separate histograms are produced for pixels classified as ?precipitation? and ?no precipitation? by coincident radar observations. The study is conducted separately for four distinct synoptic types: cold fronts, warm fronts, cold-air convection, and mesoscale convective systems (MCSs). A method is presented that uses this information to delineate areas of precipitation. It is found that the use of combined infrared and visible satellite data yields better results than using infrared alone for all four synoptic types and is better than visible date alone for the majority. Use of visible data alone is better than using infrared data by itself, except for warm-front cases. The results indicate that the ability of the satellite data to delineate precipitation decreases in the following order of synoptic regime: cold frontal, MCS, warm frontal. The most difficult regime to delineate is cold-air convection.