University of Western Australia
A study by an international team of researchers has predicted more El Nino events are likely to occur during the next decade.
The study, co-authored by Professor Chari Pattiaratchi, from UWA’s School of Engineering and Oceans Institute, and Professor Arnoldo Valle-Levinson, from University of Florida and 2024 Gledden Fellow at UWA, was published in Environmental Research Letters.
“The global atmosphere-ocean system is dominated by the El Nino Southern Oscillation events which have a significant influence on rainfall and air and sea temperatures around the globe,” Professor Pattiaratchi said.
“These events impact people’s safety, food, water, health, and economy and our research has found they are likely to occur more often.”
El Nino Southern Oscillation events are related to variations of sea surface temperature anomalies in the tropical Pacific Ocean with periods varying between two and seven years. Astronomical tides are controlled by the moon-sun-earth system over different times scales.
The study examined the gravitational pull of the moon on the oceans and its implications on water and air temperatures, rising sea levels, coastal flooding, rain, river discharge and heat transport.
Researchers analysed long-term climate indices and found a strong relationship between tidal variability and El Nino events.
The findings suggest that astronomic forces may influence El Nino events and indicate the possibility of more of these events occurring over the next decade.
“The ocean off WA has a strong connection to the Pacific Ocean through Indonesia and therefore is influenced by El Nino Southern Oscillation,” Professor Pattiaratchi said.
“El Nino events results in weaker Leeuwin Current and a stronger Capes Current, less likelihood of marine heat waves, stronger southerly winds and sea breezes, and lower mean sea levels. There is also the possibility of lower winter rainfall.”