Imágenes TRMM para identificar patrones de precipitación e índices ENSO en Ecuador

Abstract

Understanding spatio-temporal precipitation patterns and how they are related to ENSO are important to predict the spatial impact of ENSO events and develop early warning systems. While ENSO has been previously studied in Ecuador using rain gauge data, its impact on the spatial rainfall pattern is largely unknown. Thus, the purpose of this study was to use the Tropical Rainfall Measuring Mission satellite imagery (TRMM) to identify spatio-temporal patterns of precipitation from January to April, the season more affected by ENSO in Ecuador, and their relation with ENSO indexes. Principal component analysis was applied over the 16-year TRMM imagery, and score time series were correlated with the tropical Pacific surface sea temperature (tP SST) of Niño 1+2 region as well as with the Trans Niño Index (TNI). Results suggest that TNI and Niño 1+2 indicators are both needed to estimate the impact of tP SST on the precipitation during JA season. Strong positive anomalies on Niño 1+2 are positively correlated with higher precipitation in coastal plain of Ecuador and below average precipitation in the Amazon region. High values of TNI are directly related to an enhancement of precipitation all over the country.