The cyclonic disturbances over the North Indian Ocean, which includes the Arabian Sea, the Bay of Bengal and the land area in between, have gone through many significant changes in recent decades.
First, the number of cyclonic disturbances in the North Indian Ocean has declined considerably over the past four decades.
Second, this decline was mostly due to a rapid decrease in the number of cyclonic disturbances originating from the Bay of Bengal, the source of most past cyclones to have made landfall in south-east and west Asia. In contrast, the number of such disturbances originating from the Arabian Sea has been steadily increasing in recent years, though the count is still relatively low. More importantly, while the frequency of disturbances has decreased, the intensity of cyclones has increased in recent decades.
