The Ocean Heat Wave Phenomenon and the Climatic Mechanisms at Play

Event type: 
27 August 2014

Climate Change Research Centre seminar room, Mathews Building, Kensington Campus, Sydney

Hillary A. Scannell
University of Maine, Orono, ME, USA
Climate Change Research Centre

Heat waves on land are becoming more frequent, intense, and persistent due to human induced climate change, and these large-scale events have had major impacts on human health and economic productivity. However, unlike terrestrial heat waves, little work has been done to understand the dynamics of heat waves in sea surface temperature. Recently, three “ocean heat waves” have been described: the 2012 event in the northwest Atlantic Ocean, the 2011 event in the east Indian Ocean, and the 2010 event in the south-central Pacific Ocean. These warming events were all regionally unprecedented and their intensities on par with the warming expected by the end of the century. Though only the north Atlantic and east Indian Ocean heat waves had documented impacts on both fisheries and ecosystems, ocean heat waves remain of great interest globally due to their potential adverse economic and ecological impacts.

At present, there is no precise definition of an ocean heat wave, and their communal properties (intensity, duration and spatial extent) have not been evaluated. I will present a detailed overview of the 2012, 2011 and 2010 ocean heat waves, while linking the commonalities between these extreme events. I will address the current challenges in indexing ocean heat waves and offer insights into the possible oceanic and atmospheric processes that give rise to these events. Furthermore, I will present developing research on the influences of the El Niño/Southern Oscillation and the Indian Ocean Dipole in preconditioning heat waves in the Indian and Pacific Oceans.