Clouds have a significant impact on our climate by reflecting one-third of incoming solar rays to space and thereby keeping our planet cooler. Changes in cloud amount, type or height can have complex feedbacks on the climate systems. While warm rain reduced significantly over Indian monsoon region, the cold rain has escalated in recent decade. Indian monsoon has seen an increase in the frequency of intense floods as well as droughts. So it is necessary to understand the instantaneous impact of clouds on the rainfall characteristics.
A team led by Dr. Vijay P. Kanawade, Assistant Professor at Centre for Earth, Ocean and Atmospheric Sciences, University of Hyderabad has published the study on the response of raindrop size distribution (DSD) to changes in the cloud and meteorological conditions during monsoon season over Pune. The rainfall is usually classified into stratiform and convective rain, where the former is steady rainfall that occurs from horizontally developed clouds and later is intense rainfall fall from vertically developed clouds like active cumulus and cumulonimbus. Over Pune, stratiform rain was more frequent, but convective rain resulted in higher rain rates. The study highlights that the DSD response to the cloud properties is opposite in stratiform and convective rainfall regimes. This occurs due to the difference in the raindrop formation mechanism associated with both regimes of rainfall. The results from the paper will help in understanding the cloud responses and thereby improve the short-term prediction of heavy rainfall events in the future.
The work is led by Mr. Abin Thomas, who is pursuing doctoral studies with Dr. Vijay Kanawade, in collaboration with Dr. Kaustav Chakravarty and Dr. Atul K. Srivastava from Indian Institute of Tropical Meteorology, Ministry of Earth Sciences.