Unprecedented warm sea surface temperature (SST) anomalies were observed off the west coast of Australia in February-March 2011. Peak SST during a 2-week period were 5°C warmer than normal, causing widespread coral bleaching and fish kills. Understanding the climatic drivers of this extreme event, which we dub "Ningaloo Niño", is crucial for predicting similar events under the influence of global warming. Here we use observational data and numerical models to demonstrate that the extreme warming was mostly driven by an unseasonable surge of the poleward-flowing Leeuwin Current in austral summer, which transported anomalously warm water southward along the coast. The unusual intensification of the Leeuwin Current was forced remotely by oceanic and atmospheric teleconnections associated with the extraordinary 2010-2011 La Niña. The amplitude of the warming was boosted by both multi-decadal trends in the Pacific toward more La Niña-like conditions and intraseasonal variations in the Indian Ocean.
Massive seagrass beds in Western Australia's Shark Bay - a UNESCO World Heritage Site - haven't recovered much from the devastating heat wave of 2011, according to a new study demonstrating how certain vital ecosystems may change drastically in a warming climate.
In recent years, enormous socioeconomic damage has been wreaked by recurrent abnormal weather events around the world. The seedbed for this abnormal weather is climate variability events on a massive spatiotemporal scale - those that cover thousands of kilometers and continue over months and years. Here we will review an article featured on the cover of the November 28, 2013 issue of Nature Geoscience on research predicting how a climate variability event in the tropical Indian Ocean, known as the Indian Ocean Dipole (IOD), will change with global warming in the future.
The increased frequency of drought observed in eastern Africa over the last 20 years is likely to continue as long as global temperatures continue to rise, according to new research published in Climate Dynamics.