Thiruvananthapuram: A sunny day in Kerala in August can be linked to the rapid warming of Indian Ocean, according to climate scientist Dr Roxy Mathew Koll. “The strength of the monsoon is dependent on the temperature difference between land and ocean. During summer, the land is usually warmer than the ocean and drives the moisture carrying monsoon winds. Now since the Indian Ocean warming is large, this temperature difference has decreased, reducing the strength of the monsoon,” he said.
He told DC over e-mail that this is also reflected in the consecutive droughts over South India, especially Kerala. “Right now, Kerala is going through the third consecutive summer monsoon drought,” he said. The senior scientist at Indian Institute of Tropical Meteorology, Pune, is the only Indian climate scientist to be a lead author of the Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate.
“India now has longer dry periods interspersed with short spells of heavy rainfall events. At IITM, our research on extreme rain events show that the climate change has led to a rise in widespread extreme rain events, leading to largescale floods over India,” he said. A warmer atmosphere holds more moisture resulting in two factors. One, the warm moist air, which is lighter than cold dry air, rises up. Two, as the atmosphere holds more moisture, it dumps all the moisture together as a heavy rainfall events. “These factors lead to erratic weather, including extreme rainfall events across the globe,” he said.
