Researchers from IIT Madras and IIT Bombay have said the rains have grown more unpredictable than before, and this bodes ill for a country whose economic well-being is critically linked to seasonal rains.
A team of IIT Madras and IIT Bombay studied the rainfall pattern in India over the past century and published the results in the peer-reviewed journal Public Library of Science, a non-profit science, technology and medicine publisher based in San Francisco. The research delved into the impact of climate change on the temporal and spatial rainfall patterns through the analysis of historic data and simulation studies.
The team comprised Dr. Subimal Ghosh and Dr. Subhankar Karmakar from IIT Bombay, Dr. K.S. Kasiviswanathan, Dr. K.P. Sudhir and Dr. Sachin Gunthe from IIT Madras along with their research students. The research was supported by the Max Planck Partner Group at IIT Madras, Department of Science and Technology, Government of India, and the Ministry of Earth Sciences.
The researchers did not observe convection-based rains, which occur in areas where there is excess moisture. This is significant as it contradicts the traditional notion of dry areas becoming drier and wet areas becoming wetter in response to climate change.
Many recent observations both at the meteorological level and from local perceptions revealed that monsoon the has grown more unpredictable than before. The research said calamities such as the Kerala floods and water scarcity in Tamil Nadu bear testimony to the vagaries of the monsoon.
Dr. Gunthe of IIT Madras said, “The regional aspects of the Indian summer monsoon rain pattern are difficult to understand because it is affected by many factors. In order to discern rainfall patterns reliably, we used the India Meteorological Department’s daily rainfall data for 1901 to 2004 and performed simulations taking into consideration phenomena such as maximum temperature, minimum temperature, rainfall and wind velocity.”
Dr. Gunthe said the model was validated with satellite-based observation from the European Space Agency-Climate Change Initiative on soil moisture.