Duration of the South America summer monsoon is increasing

We studied the interannual variability of the beginning, end and duration of South American monsoon system ( SAMS ) for the period 1956–2006. The mean beginning date was 10 October, whereas the mean end date was 6 April, and the mean duration was 174 days. The beginning of SAMS showed a tendency to start earlier and the end date showed a tendency to delay; thus, the duration of SAMS showed a tendency to increase by about 7 days in 10 years. We found that the beginning and end dates of SAMS have significant positive correlation with sea surface temperature ( SST ) of an earlier period at southwest Africa in the South Atlantic Ocean. This suggests the potential of SST in the prediction of the beginning and end dates of SAMS .