A senior climate scientist warned that the warming of the Arabian Sea is contributing to the development of deep cloud systems, which are causing extremely heavy rainfall in Kerala over shorter periods. This phenomenon is also heightening the risk of landslides in the region. Early Tuesday, a series of landslides in the hilly areas of Kerala's Wayanad district, triggered by extremely heavy rain, resulted in the deaths of at least 123 people and injured 128 others. Many people are feared to be trapped under the debris.
S Abhilash, the director of the Advanced Centre for Atmospheric Radar Research at Cochin University of Science and Technology (CUSAT) said Kasargod, Kannur, Wayanad, Calicut, and Malappuram districts have been receiving copious rainfall due to the active monsoon offshore trough affecting the entire Konkan region for the last two weeks.
After two weeks of continuous rainfall, the soil was already saturated when a deep mesoscale cloud system formed off the coast in the Arabian Sea on Monday. This system caused extremely heavy rain in Wayanad, Calicut, Malappuram, and Kannur, leading to localized landslides, a senior climate scientist told PTI. "The clouds were very deep, similar to those seen during the 2019 Kerala floods," Abhilash said.
Also Read| Wayanad Landslides: Death Toll Climbs to 143; Bad Weather Disrupts Rescue Operation in Kerala.
He noted that scientists have observed a trend of very deep cloud systems forming over the southeast Arabian Sea. He added that, at times, these systems move inland, similar to the event in 2019. "Our research found that the southeast Arabian Sea is becoming warmer, causing the atmosphere above this region, including Kerala, to become thermodynamically unstable," Abhilash said.
He explained that climate change is causing the rain-bearing belt with deep clouds to extend southward, which is driving the increase in extremely heavy rainfall.
Research by Abhilash and other scientists, published in the Climate and Atmospheric Science journal in 2022, indicated that rainfall along the west coast of India is becoming more convective. Additionally, a 2021 study by Abhilash and researchers from IITM and IMD, published in Elsevier, found that a hotspot of heavy rainfall in the Konkan region (between 14 degrees and 16 degrees north) appears to have shifted southward, potentially leading to severe consequences.
The India Meteorological Department (IMD) reported that automatic weather stations across Thrissur, Palakkad, Kozhikode, Wayanad, Kannur, Malappuram, and Ernakulam districts recorded rainfall amounts ranging from 19 cm to 35 cm.