The warming Arabian Sea is contributing to the formation of deep cloud systems, resulting in extremely heavy rainfall in Kerala over short periods of time. This phenomenon increases the likelihood of landslides in hilly areas like Wayanad, where at least 123 people have died and 128 have been injured due to recent landslides. S Abhilash, director of the Advanced Centre for Atmospheric Radar Research at CUSAT, explained that the active monsoon offshore trough affecting the Konkan region has led to significant rainfall in northern Kerala districts such as Kasargod, Kannur, Wayanad, Calicut, and Malappuram. The saturated soil from two weeks of rainfall has exacerbated the situation.
Formation of deep cloud systems
Abhilash highlighted that a deep mesoscale cloud system formed off the Arabian Sea coast on Monday, leading to extremely heavy rain in Wayanad, Calicut, Malappuram, and Kannur. He noted that similar deep cloud formations were observed during the 2019 Kerala floods.
Research on atmospheric instability
Research by Abhilash and other scientists indicates that the southeast Arabian Sea is warming, causing thermodynamic instability in the atmosphere above Kerala. This instability, linked to climate change, allows the formation of deep clouds, extending the rain-bearing belt southward from the northern Konkan belt.
Studies on rainfall patterns
Studies published in Climate and Atmospheric Science and Elsevier journals found that rainfall along India's west coast is becoming more convective, with heavy rainfall hotspots shifting southward. This shift increases the probability of landslides in Kerala's Western Ghats during the monsoon season.
Severe rainfall recorded
According to the India Meteorological Department, several automatic weather stations in Kerala's districts recorded rainfall between 19 cm and 35 cm. Some stations reported over 30 cm of rain in 24 hours. The Met Office predicts continued heavy rainfall in the state over the next two days.
Erratic monsoon patterns
Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, stated that monsoon patterns have become erratic, leading to more rainfall in shorter periods. This change results in frequent landslides and floods along the Western Ghats from Kerala to Maharashtra.
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