| Indian Ocean SST and precipitation in the littoral regions of the Indian Ocean are examined with the aim of assessing predictability of precipitation in regions with critical socio-economic impact. Empirical relationships are found to varying degrees and with differing degrees of statistical stationarity. We find SST precursors to monsoon rainfall in India, Africa, Indonesia and Australia and investigate the degree to which these precursors are independent of ENSO. We find significant correlations between SST and precipitation with SST leading by 1 to 4 seasons, thus suggesting the possibility of forecasting precipitation with long lead. An attempt is made to interpret these relationships in the context of existing theories regarding the climate of the Indian Ocean and the monsoons, and the relationship between the monsoon climate and the variability of the Indian and Pacific Oceans. We test the hypothesis that the empirical relationships between SST and rainfall are related to SST variability in the Indian Ocean associated with the tropospheric biennial oscillation (TBO). We find empirical evidence to support this hypothesis. |
