Multidecadal variability in the climate system over the Indian Ocean region during the austral summer

Abstract

Decadal to multidecadal variability across the Indo-Pacific region has been detected in sea surface temperature (SST), mean sea level pressure (MSLP), and surface wind fields over both the landmasses and the oceans. The broad periods before and after the 1940s show important differences in features such as Indian southwest monsoonal rainfall and circulation patterns, relationships between austral summer rainfall in southern Africa and the El Nino-Southern Oscillation phenomenon, and Australasian MSLP. In an effort to isolate such fluctuations and work toward understanding the physical dynamics operating on such timescales, SST, MSLP, atmospheric circulation, vertical motion, and cloudiness anomalies are constructed and analyzed for austral summer (JFM) conditions over the Indian Ocean region during four 21-yr epochs since 1900. -from Authors