EAPSI: Impacts of El Niño-Southern oscillation on Indian Ocean heat waves

Scannell Hillary A, Kennebunkport ME

Investigators

Abstract

Abrupt changes in sea surface temperature (SST) are known to disrupt fishery productivity and marine ecosystem functioning by affecting the survival and distribution of many commercially important marine species. A recent ocean heat wave in 2011 occurred off Western Australia and caused unprecedented warming in the southeast Indian Ocean. Understanding the causes and frequency of these extreme warming events are of particular interest to societal and marine sectors due to their adverse consequences. The frequency of Indian Ocean heat waves will be addressed in collaboration with Dr. Matthew England from the University of New South Wales in Australia. This project will use a unique combination of statistical and state-of-the-art climate models to quantify changes in the frequency of ocean heat waves in relation to the decadal variability of the El Niño-Southern Oscillation (ENSO). Dr. England is a noted climate expert in this region and has made significant contributions towards understanding the variability of SST in the Indian Ocean. This project will model El Niño teleconnection patterns in the equatorial Pacific with the spatial extent of extreme warming events in the Indian Ocean using Bayesian statistics coupled with global circulation model experiments. Much of the variance in Indian Ocean SST can be explained by ENSO-induced teleconnection patterns that manifest in the tropical Pacific Ocean. This suggests that Indian Ocean heat waves are not stochastic phenomena, but are rather modulated by a forced response due to ENSO. The transient interactions between ENSO teleconnections and extreme SST in the Indian Ocean are not completely understood, and the emergence of new, coupled climate models justifies the need for examining changes in climate variability and extreme oceanographic events. This NSF EAPSI award is funded in collaboration with the Australian Academy of Science.