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.
Preliminary findings of a comprehensive scientific survey examining the impact of the climate change-related 2016 mass bleaching in the Maldives indicate that all reefs surveyed were affected by the event. Approximately 60% of all coral colonies assessed - and up to 90% in some sites - were bleached.
Preliminary findings of a comprehensive scientific survey examining the impact of the climate change-related 2016 mass bleaching in the Maldives indicate that all reefs surveyed were affected by the event. Approximately 60% of all coral colonies assessed - and up to 90% in some sites - were bleached.
A new study published in the international journal Nature Communications has revealed how Western Australia's coral reefs have been affected by changing ocean currents, rising sea surface temperatures and sea level variability.
The role of COVID-19 pandemic lockdown in improving air quality was reported extensively for land regions globally. However, limited studies have explored these over oceanic areas close to high anthropogenic activities and emissions. The Bay of Bengal (BoB) basin is one such region adjacent to the highly populated South Asian region. We find that Aerosol Optical Depth (AOD) over the BoB declined by as much as 0.1 or 30% during the peak lockdown of April 2020 compared to long-term climatology during 2003-2019. Simultaneously, the sea surface temperature (SST) rose by 0.5-1.5°C over the central and north-western parts of the BoB with an average increase of 0.83°C. We show that up to 30% of this observed warming is attributable to reduced atmospheric aerosols. The study highlights the importance of anthropogenic emissions reduction due to COVID lockdown on short-term changes to SST over ocean basins with implications to regional weather.
The role played by oceans - not only the Atlantic and Pacific, but also the Indian Ocean - in South American climate variability is one of the topics researched by Marcelo BARREIRO, Head of Atmospheric Sciences at Uruguay's University of the Republic (UDELAR).