New Delhi, Nov. 9 -- Bulbul, a very severe cyclonic storm in the Bay of Bengal, which is likely to intensify further and cross the Sunderbans delta in West Bengal and Bangladesh, is the seventh cyclonic storm this year, of which four have unusually been in the Arabian sea.

The high overall number -- between 2011 and 2018, the number of cyclones was less than five a year, according to India Meteorological Department (IMD) data -- as well as the activity in the Arabian sea is being seen by scientists as yet another impact of climate change, which causes surface sea temperatures to rise.

Four cyclones-Vayu, Hikka, Kyarr and Maha -- developed over the Arabian Sea this year and three in the Bay of Bengal-Pabuk, Fani and Bulbul.

Among these, K...