Adjustment of the Convective-Stratiform Technique (CST) to estimate 1991/93 El Nino rainfall distribution in Ecuador and Peru by means of Meteosat-3 IR data

Resumen

This Letter describes the adjustment of the Convective-Stratiform Technique (CST) to estimate 1991-93 El Nin o rainfall in Ecuador and Peru by means of IR radiation data recorded by the Meteosat-3 VISSR sensor. The adjustment includes (1) a regionalization of a one-dimensional cloud model using local radiosonde data, (2) a field-of-view correction of the VISSR-derived cloud top temperature to model requirements and (3) an adapted discrimination scheme between raining and non-raining clouds. Validation reveals a strong correlation between calculated and observed rainfall for all climatic regimes and rainfall intensities within the study area.