What’s causing extreme weather in Tamil Nadu?

CHENNAI: As per meteorologists, all the prime oceanic parameters — La Nina, Indian Ocean Dipole (IOD) and MJO (Madden-Julian oscillation) — are in favourable positions at the same time, favouring the formation and strengthening of weather systems in Bay of Bengal.

Besides, contribution of climate change cannot be negated. Rise in global temperatures has increased frequency of heavy rains. The Indian Ocean is warming at a faster rate, with sea-surface temperatures (SST) rising above average. 26.5 degree Celsius is the threshold value, past which conditions are favourable for rapid intensification of weather system. SST now stands close to 29 degrees.

GP Sharma, president-meteorology and climate change, Skymet Weather, said, “The impact of rise in ocean temperature is more than compared to land temperature. This has also increased the shelf life of weather systems, which then tends to travel inland for longer duration.”

“Climate change has led to a rise in SST, resulting in sea level rise by 10 to 15 per cent,” said Mrutyunjay Mohapatra, director general of meteorology, IMD. Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, Pune, said, “An important aspect of climate change for the east coast is that extreme weather and climate events are overlapping. Now, sea level is also rising in the background. Hence, the flood level due to storm surge and rains are rising year on year,” Roxy said.