Bhubaneswar: For the second time in successive months, Bhubaneswar rocked the mercury chart in the country. The Capital City of Odisha ruled as the hottest spot in the country in the last week of February, and the redux happened on March 31.
What has alarmed weather watchers here is while in the last week of February the IMD had not termed the abnormal rise of the mercury in the city as a heatwave, on March 31 the IMD officially informed that 'heat wave' ruled in Odisha and Bhubaneswar emerged as the hottest place in the country.
In fact, in the annals of the City's climatic history, the shooting up of mercury to 44.2 deg C on Wednesday has been a record.
Since the context of the Temple City climbing up to the hottest spot in India during the two successive months of February and March has been different, weather scientists, therefore, assign different causes behind the sizzling dance of mercury.
WHY BHUBANESWAR TURNS 'TATLAGARH'?
Listen to what heatwave expert and senior scientist in IMD Naresh Kumar says.
"As per our study of heatwaves in the country since 1961-2010, it has been observed that a heat trough or low runs from Jharkhand to north coastal Andhra Pradesh during the summer months of March to May. In tandem with the development of such a thermal low, when the hot and dry north-westerly winds are strong, the highest maximum temperature will be recorded in coastal stations, not interior places."
THE EVIDENCE: As per IMD weather analysis, the north-south trough from Jharkhand to north Coastal Andhra Pradesh extending up to 1.5 km above mean sea level persisted yesterday and today. The hot and dry wind flow to Odisha from the north-western direction had been the distinct weather feature on Wednesday. Moreover, the wind was strong too.
Since this phenomenon had propelled the mercury high in western districts, the real heat scene moved to Bhubaneswar. And the City recorded the highest temperature in the country.
WHY BHUBANESWAR, NO OTHER COASTAL PLACE?
Since Bhubaneswar is the interior plain among the coastal region, the mercury goes berserk here every time such weather phenomenon persists.
However, the phenomenon of 'urban heat island' plays its part in heating up the Temple City as it is the most urbanised city in Odisha.
As per the National Institute of Disaster Management (NIDM), Urban Heat Island (UHI) effect comes into play in Bhubaneswar as the city has more heat-absorbing surfaces like rooftops, buildings and paved surface (a new-found love of the Smart City development authorities).
Moreover, the trapping of hot air between the buildings, limited tree cover and other heat-trapping and heat-inducing factors such as fuel combustion and air conditioning, make the UHI play a big role in seeding an abnormal rise in the temperature when such weather conditions manifest in Odisha during summer, especially in months of March- April.
HISTORY OF HEAT WAVES IN ODISHA
- As per a study by senior scientist and heatwave expert Naresh Kumar, coastal regions in Odisha (including Bhubaneswar) have recorded the longest heatwave spell of 14 days during the study period of 1961-2010.
- Sundargarh witnessed the longest severe heatwave spell of 9-days during the period of 1961-2010.
- Bhubaneswar and other nearby are the only places in the State to record heatwave during the period of 1961-2010. And the duration has been only around 2-days. The trend was witnessed in 2016 and this March (2021).
- Coastal areas like Bhubaneswar, Cuttack and nearby places experience longer duration heatwave in April than their western counterparts.
- The month of May proves a blast furnace for Western Odisha. The 2021 forecast predicts a hotter western Odisha this May.