Ajil Kottayil, scientist at Advanced Centre for Atmospheric Radar Research, Cochin University of Science and Technology, gives his take on the heavy rain in Kerala.
The current spell of heavy rains over Kerala is the result of severe depressions in the south east Arabian Sea and Bay of Bengal.
This situation has intensified the monsoon low-level jet stream which is an important component for the formation of rain-bearing clouds during monsoon season.
For 3-4 days
The depression once triggered can cause extreme rainfall, which will continue for three or four days. The depth of the cloud determines the amount of rain it can deliver; a deep cloud causes heavy rainfall while for the shallow forms, we may expect moderate rain.
The thunder and lightning spells witnessed during the current rainy season indicate the formation of deep clouds. Satellite data analysis reveals an intense depression and consequently the formation of deep clouds.
This scenario has resulted in the intense downpour currently being witnessed in Kerala. In the regions that witnessed landslides, there is a strong possibility of cloudburst.
To subside soon
This situation will be suppressed in the next couple of days due to presence of a low-pressure region near the Gujarat coast which may reduce the intensity of the monsoon low-level jet stream and hence the strength of the rain.
The intensification of typhoons in the next few days over Pacific Ocean could also neutralise the conditions which have led to heavy rainfall.
Preparedness
The time and again incidence of extreme rainfall reiterates that climate change is clearly in action. It is also high time that the government and people of Kerala begin to think strategically on measures for future preparedness and mitigation, to avert the dangers from flooding which could happen in future monsoon seasons as well.
(As told to
G. Krishnakumar)
