MELBOURNE, Oct. 20 (Xinhua) -- The strong El Nino currently underway in the Pacific Ocean raises the specter of marine heatwaves and coral bleaching once again threatening Australia's Great Barrier Reef, new research finds.
The research has revealed the complex interplay of atmospheric patterns and weather systems thousands of kilometers apart that can combine in a recipe potentially fatal for coral reefs, according to a statement released Monday by Australia's Monash University.
Sea-surface temperatures in the Coral Sea off Australia's northern Queensland can rise during "doldrums," periods of weak winds, reduced cloud cover and dry, descending air, researchers said, adding when these conditions persist, the ocean heats up for longer, potentially accelerating warming and contributing to coral bleaching.
An active El Nino raises the level of background threat, and a prolonged spell of doldrums during a strong El Nino phase could contribute to marine heatwaves and increase the risk of harmful mass coral bleaching, according to the study published in Weather and Climate Dynamics.
The researchers at Monash University and the University of Melbourne found that easterly trade winds normally cool reef waters by stirring the upper ocean and helping heat escape its surface, but persistent doldrums suppress this natural cooling process.
The team said their findings provide the most comprehensive explanation yet of how doldrums form and persist over the Great Barrier Reef, with future work exploring whether existing computer models can predict these events. ■
