Tamil Nadu heatwave scorching Kerala

Kochi: The  sweltering heat in the past two days has made the people worry about the climatic changes occurring in the state.   The scientists say that it  is the result of an unprecedented phenomenon taking place in the atmosphere.

“Usually,  wind comes from different directions at different layers in different heights in the atmosphere. In Kerala this happens from the Arabian Sea, Indian Ocean and Tamil Nadu region. Interestingly, for the past two days, this has happened in all layers only from the Tamil Nadu region where dry weather exists, crossing the Western Ghats,”  says Dr  M.G. Manoj, research scientist with the newly-established Advanced Centre for Atmospheric Radar Research at the Cochin University of Science and Technology.

Dr Manoj told DC on Monday  that the Western Ghats stand at 1 to 1.5-km height bordering the state in the east.

The dry wind crossing the mountains move downwards. “In that motion,  compression takes place and leads to the process called compressional warming or adiabatic warming by which the heat increases,” he said.

Another phenomenon adding to the escalation in atmospheric temperature for the past two days has been  the presence of dark clouds cover in the afternoon.

“When the atmosphere is clear during morning and until afternoon, it generates heat and by evening if the sky remains clear, the heat gets reradiated into the outer space lowering the surface temperature. However, if the sky is cloudy, this process fails to take place and the heat remains trapped in the lower atmosphere leading to sweltering heat. Humidity in the atmosphere has also increased during the past one week,” said Dr Manoj.

During monsoon, the wind blows from the south-west direction while during other seasons it blows from north-east and south-east directions, he said.