Squall lines and rainfall over Western Africa during summer 1986 and 87

• Published in: Meteorology and atmospheric physics Vol. 90; no. 3-4; pp. 215 - 224
• Main Authors: GAYE, A, VILTARD, A, DE FELICE, P
• Format: Journal Article
• Language: English
• Published: Wien Springer 01-10-2005; New York, NY Springer Nature B.V; Springer Verlag
• Subjects: Earth, ocean, space; Exact sciences and technology; External geophysics; Meteorological satellites; Meteorology; Rain; Rainfall; Sciences of the Universe; Storms; Storms, hurricanes, tornadoes, thunderstorms; Water in the atmosphere (humidity, clouds, evaporation, precipitation); West Africa; Squall line; rainfall; Meteorological phenomenon; atmospheric precipitation; Space remote sensing; Africa; daily variations; Summer; Satellite observation; Pluviometry; Meteosat satellites; Severe weather; Thermal imaging; Measuring network
• ISSN: 0177-7971; 1436-5065
• DOI: 10.1007/s00703-005-0116-0

Using digitized IR images from the European satellite Meteosat, 153 squall lines (SLs) were observed over Western Africa during July, August and September 1986 and 87. The SL mean rainfall volume was computed using the daily rainfall amounts of more than 800 raingauges: 15km3 in 1986 and 22.5km3 in 1987. A mean amount of 15mm was collected per rainy episode at a given station, however, as only about half of the stations situated under a SL experienced a rainy episode, the rainfall amount averaged along the total SL's swath was 6.8mm. With the help of the 8 daily Meteosat slots the SL's area daily variation could be estimated: namely a minimum around noon and a maximum around midnight. Using the SLs displacements (east-west) one had access to the daily variation of the rainfall volume, a minimum in the morning and a maximum toward the end of the afternoon, as already found by several authors who used Meteosat images. [PUBLICATION ABSTRACT]