Linkage between Malawi Rainfall and Global Sea Surface Temperature

抄録

  Correlations between summer rainfall in Malawi and global sea surface temperature (SST) were studied to elucidate the linkage between SST and rainfall. We used SSTs for the period 1979–2011 and rainfall data for 1981–2012 from nine stations, which were grouped into two zones on the basis of inter-station rainfall correlations. The Pearson correlation coefficient was used to test the hypothesis that the main influence on summer rainfall in Malawi was the Indian Ocean SST rather than the Pacific or Atlantic SST. We found that summer rainfall was more strongly correlated with the Indian Ocean SST compared to the Atlantic and Pacific Ocean SSTs. The correlations were more significant for northern stations than for central and southern stations. These results agree with other findings, the suggestion being that different climatic drivers influence the climate of different parts of Malawi. Northern areas are strongly influenced by the SST Indian Ocean dipole, whereas central and southern areas are strongly linked to the SST in the subtropical Indian Ocean. The results reveal that SST in the Atlantic Ocean off South Africa also affects Malawi rainfall. We conclude that the Indian Ocean SST, including in particular the SST dipole strongly influences Malawi rainfall.