Effect of anomalous warming in the central Pacific on the Australian monsoon

The influence of sea surface temperature (SST) anomalies in the central Pacific Ocean on rainfall variability over Australia is investigated using observations and idealized simulations from an atmospheric general circulation model. We show that the SST warming centered at 180 degrees W is associated with increased monsoon precipitation over northern Australia from January to February and a decrease in December and March over the same region, leading to a shorter and more intense monsoon period. In recent years SST anomalies commonly associated with El Nino events have often exhibited a peak signature in the central, not eastern, Pacific. These so-called El Nino Modoki events are shown here to result in a markedly shorter and more intense Australian monsoon season. Citation: Taschetto, A. S., C. C. Ummenhofer, A. Sen Gupta, and M. H. England (2009), Effect of anomalous warming in the central Pacific on the Australian monsoon, Geophys. Res. Lett., 36, L12704, doi:10.1029/2009GL038416.