SYDNEY, July 26 (Xinhua) -- Global El Nino weather events can be traced to two main atmosphere-ocean oscillations, a discovery that significantly improves the understanding of one of the world's most crucial and complex climate processes, according to latest Australian-linked research.
"We used to think of El Nino being fairly well explained by simple conceptual models," the study's co-author Dr Dietmar Dommenget, from Monash University's School of Earth, Atmosphere and Environment, said in a statement on Thursday.
"However, as the number of El Nino events we have observed has increased, its complex behavior has become more apparent, revealing interesting interactions with the atmosphere and other ocean basins," he said.
El Nino events are characterized by an unusual warming of the central to eastern equatorial Pacific, which can last up to one year, according to the university. Its remote "ripple effects" can not only be found in the atmosphere, but also in ocean currents, ecosystems, the occurrence of natural disasters and economies.
The study involved a group of 40 climate scientists from 11 countries analyzing large amounts of climate observations and computer model simulations covering temperature, wind and ocean current configurations to trace the main mechanisms behind El Nino.
Weather events and atmospheric circulation changes induced by temperature changes in the Indian and Atlantic oceans were found to be important factors behind the "constant excitation" of tropical Pacific climate systems, interactions that in turn helped fuel El Nino irregularities, said the researchers.
"Our study reveals that there is a hidden structure in the seemingly chaotic and unpredictable occurrence of El Nino events," said the study's lead author Axel Timmermann, from South Korea's Pusan National University. The findings have been published in scientific journal Nature.
The next step will be to conduct more comprehensive climate modeling studies in a more realistic setting to determine any shifts in El Nino characteristics amid climate change, said the researchers.
