Maritime continent winter circulation as a predictor of El Nio-Southern Oscillation (ENSO) influence on Ethiopia summer rainfall

摘要

Summer rainfall over the cropping region of Ethiopia is related to the precursor winter circulation around the Maritime Continent and El Niño–Southern Oscillation (ENSO) development and influence. Investigation of this link reveals that sea surface temperature (SST) in the north Indian Ocean and China Sea are anomalously cold and there are low level north-westerly wind anomalies around the Maritime Continent prior to dry summers in Ethiopia. The analysis shows that wind anomalies spread into the Pacific - increasing convection, and across the Indian Ocean and Africa - suppressing convection. Two indices that represent Asian winter monsoon penetration near the Maritime Continent are used to predict Ethiopian summer rainfall at long-lead time. The hindcast fit of the statistical algorithm exceeds 50% during the satellite era (1981-2014).