Kochi: The El Nino with continuous warming of sea surface temperatures in the tropical Pacific Ocean leading to anomalous atmospheric circulation coupled with an anticyclone circulation overhead of South Indian Peninsula is leading to extreme hot climate and very less summer rain over Kerala, says a key Met scientist.
“The year 2019 was expected to witness an El-Nino, with continuous warming of sea surface temperatures in the tropical Pacific Ocean. The Australian Meteorologi- cal Bureau predicts a 70% chance of El-Nino this year. El-Nino results in below average rains over the Indian region and increased surface temperatures,” says Dr M. G. Manoj, a research scientist with Advanced Centre for Atmospheric Radar Research (ACARR) of Cochin University of Science and Technology (Cusat) in Kochi.
“The east coast India has already started warming due to anomalous atmospheric circulation. The presence of an anticyclonic circulation, another significant weather controlling parameter, overhead South Indian Peninsula region, blocks vertical development of clouds. This leads to clear-sky condition and prevalence of above-average temperatures across the state.”
He also pointed out that the Arabian Sea adjoining Kerala coast is also unusually warm now with the Sea Surface Temperature (SST) touching as high as 30° C.
“Generally SST greater than 26.5 °C is favourable for low pressure/depression formation and widespread rainfall. However, the abnormal anticyclone circulation is preventing their formation,” Dr Manoj said explaining the reason for very less summer rain this time.
“This is the time when the sun’s rays are falling perpendicular to the Equator around March 21, known as the spring equinox. We expect an increase in temperature during and after this period. Now there is a shortage of pre-monsoon rainfall across the state with districts such as Kasaragod, Kannur, Kozhikode and Palakkad witnessing a complete no-rain period. This also has amplified the heat anomaly over these places.”
He pointed to another factor in the urban heat island (UHI) effect, which characterises warmer air over urban/metropolitan region compared to its surroundings, due to anthropogenic activities including deforestation, land use/land cover changes in the form of reduction in natural canopy and marshal lands, spatial expansion of tarred roads with black surface, increased number of concrete buildings, vehicles and air-conditioners apart from burning of waste materials and wildfires.
Sunstroke, burn cases increase
More people in the state have suffered from sunstrokes and burns with the mercury level continuing to rise. Two cases of sunstroke, 23 heat rashes and 35 sunburns were reported from various places on Tuesday. The sunstroke occurred in Ernakulam district.
The Indian Meteorological Depar -tment has predicted 3 to 4 degrees rise in temperatures in many parts till Thursday.
The districts likely to be affected are Thiruvananthapuram, Kollam, Pathanamt- hitta, Ernakulam, Thrissur, Malappuram, Kannur and Kasargod. The public have been advised to avoid direct sun from 11 a.m. to 3 p.m. A total of 148 chickenpox cases were also reported on Tuesday, while the number was 147 on Monday....