Laboratory for
Climatology and Remote Sensing

Abstract:

An analysis of heavy precipitation dynamics during the strongest Super El Niño of the last century (1997/98) for Ecuador and northern Peru is presented. Additionally, a unique event of severe flooding in the Rio Ica catchment (central Peruvian Andes) during this event is examined. All investigations are based on the exploitation of satellite data. Precipitation maps are calculated by means of the Enhanced Convective Stratiform Technique (ECST) and Cloud Motion Winds (CMW) are extracted from time series of GOES-8 data. AVHRR-based sea surface temperatures are also used as data of the Precipitation Radar (PR) onboard the TRMM platform. Spatio-temporal dynamics of heavy precipitation during EN 1997/98 has been proven to reveal the same mechanisms as during a normal El Niño (1991/92). However, rainfall amount is significantly increased. Evidence for clear spill-over effects of cirrus remainders from the Amazon on rainfall formation in the coastal lowlands could be found by means of TRMM PR data and CMWs. The study reveals that the severe flood event in the Rio Ica catchment was caused by anomalous strong zonal trades which initiated the heavy precipitation event from the Amazon lowlands.