IMD looking for a link between regional temperature and transmission of Covid-19
There is no established link between temperature and virus transmission. We are only trying to study if there is.
DS PAI, senior scientist, IMD Pune
NEW DELHI: The April-May-June (AMJ) season is likely to be warmer than normal in most parts of the country, according to India Meteorological Department’s (IMD) seasonal outlook for temperatures during the summer season released on Monday.
IMD is also monitoring temperature data in all districts and sharing it with the National Disaster Management Authority (NDMA).
According to scientists, various agencies are correlating this temperature data with Covid-19 cases and transmission patterns -- the pursuance of a yet unproven theory that high temperature is the silver bullet that could stop spread of the coronavirus disease.
A non-peer-reviewed study by Sun Yat-sen University in China’s Guangzhou, published on February 22, contended that every 1-degree-Celsius rise in temperature reduced the spread of the disease, and concluded that the Sars-CoV-2 virus’s sensitivity to high temperature could prevent it from spreading in warmer countries during the summer.
Another non-peer-reviewed study from Harvard T.H. Chan
School of Public Health last month, however, pointed to sustained Sars-CoV-2 transmission in diverse climate conditions, from cold and dry provinces to tropical locations even within China, and concluded that “weather alone not necessarily lead to decline in case counts”.
IMD said a link between temperature and the virus is yet to be established.
“There is no established link between temperature and virus transmission. We are only trying to study if there is. Sharing anything on this will only create confusion because we are at a critical stage. Once data is analysed, we can arrive at a conclusion. We can expect to hit 35 degrees Celsius in north India in early April, and 40 degrees Celsius by April-end. Already parts of central and peninsular India are recording maximum temperature of 35 degrees or more,” said DS Pai, senior scientist at IMD Pune.
This summer, the frequency of heat waves in the core heat wave (HW) zone is also likely to be slightly above normal, according to IMD’s outlook. Regions that can expect average maximum temperature to be 0.5 to 1 degrees Celsius above normal include east and west Rajasthan, west Madhya Pradesh, Gujarat, Konkan, Goa, central Maharashtra, Marathawada, north and south interior Karnataka, coastal Karnataka, Rayalaseema and Kerala.
States and regions where the average minimum temperature is likely to be warmer than normal by more than 1 degree Celsius include east and west Rajasthan and Gujarat.
According to the outlook, there is 40% probability that maximum temperatures in the core heat wave zone during April to June 2020 will be above normal. The core HW zone covers Punjab, Himachal Pradesh, Uttarakhand, Delhi, Haryana, Rajasthan, Uttar Pradesh, Gujarat, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, West Bengal, Orissa,Telangana, Marathwada, central Maharashtra and coastal Andhra Pradesh.
Currently, there is a warm El Niño-Southern Oscillation (Enso)-neutral condition prevailing over the equatorial Pacific Ocean. The latest Monsoon Mission Coupled Forecasting System (MMCFS) forecast indicates that the Enso-neutral conditions are likely to continue during the entire forecast period.
“West Odisha has already recorded 40 degrees Celsius. Summer is approaching, but there is a delay in north India because of an unusually high number of western disturbances (WD). There were over six WDs in March. Another WD is expected today which will again bring rain to some regions of northwest India and reduce maximum temperature for a few days,” said RK Jenamani, senior scientist at National Weather Forecasting Centre.
According to IMD, a heat wave is recorded when the maximum temperature is 4-5 degrees Celsius above normal in regions where the normal maximum temperature is more than 40 degrees; and 5-6 degrees above normal where the normal maximum temperature is less that 40 degrees. A heat wave is also declared when the actual maximum temperature remains above 45 degrees Celsius at any place irrespective of its normal maximum temperature.