Marine heatwaves in the Bay of Bengal cause heavier monsoon rains. Photo: © Ian.CuiYi /

Accurate monitoring of marine heatwaves needed for the Indian Ocean

A recent study shows that marine heatwaves in the Indian Ocean affect the Indian summer monsoon rainfall. The incidence of marine heatwaves (events with extremely high temperatures) has increased because of climate change. According to the study, marine heatwaves in the western Indian Ocean and the north Bay of Bengal are coupled with a reduction in monsoon rainfall over the central Indian subcontinent. Monsoon rainfall over southwest India is increasing, however, due to marine heatwaves that occur in the Bay of Bengal.

At present, a deeper understanding of the relationship between marine heatwaves (and between other factors) and rainfall is hampered by a lack of necessary monitoring data. Such data could be also used for forecasting marine heatwaves in the Indian Ocean.

A roadmap known as InDOOS, comprising four primary improvements to the current observation system, has been proposed. These improvements concern the upscaling of biological and chemical measurements, expanding monitoring to the western tropics, higher resolution for upper ocean processes, and developments regarding key coastal regions as well as the deep ocean.



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