A new study from the Centre for Earth, Ocean and Atmospheric Sciences (CEOAS) at the University of Hyderabad (UoH) throws light on the impact of climate change on the water-holding capacity of the atmosphere and found that warming exacerbates the intensity of rain events.

The scaling of extreme rainfall with temperature showed a clear shift in the peak temperature, suggesting that very extreme rainfall events may intensify.

The study was carried out by Dr Stella Jes Varghese, a Science and Engineering Research Board (SERB) National Post-doctoral Fellow at CEOAS, under the guidance of Professor Ashok Karumuri. The collaborative research also involved scientists from CSIR Fourth Paradigm Institute, Indian Institute of Technology (IIT) Bombay and Meteorological Research Institute (MRI) in Japan.

The study anticipates that the altered radiative forcing due to global warming will not only heat up the upper atmosphere but also stabilise it, offsetting the effect of increased humidity on precipitation intensity. This argument finds support in the lack of a pronounced increase in vertical pressure velocity.

The research also identified a future decrease in cloud cover along with an increase in cloud water content, suggesting a shift in the cloud type to more convective clouds in future, leading to extreme rains. As a result, the Indian summer monsoon season is expected to have short bursts of convective rains leading to extreme rainfall events but drier conditions for most days.

For the study, researchers used outputs from present-day climate simulations and future climate change projection experiments conducted using a high-resolution global climate model of Japan. For a more robust result, runs from different high resolution models have to be incorporated, said a release from the university.