Hottest across globe, this April wasn’t harsh in India
Globally, this April was the second hottest on record in 141 years of record keeping by National Oceanic Atmospheric Administration (NOAA). But India was among the few spots in the world which recorded below average temperature in April. Parts of North America also recorded an unusually cold April.
April 2016 was the hottest April on record.
Scientists in India are trying to ascertain what could be causing such mild weather through the summer months -- and even in mid-May. Kota in Rajasthan and Khajuraho in Madhya Pradesh recorded the highest temperature on Wednesday at 41.6 degrees C, which is 3 to 4 degrees C lower than normal, according to the India Meteorogical department (IMD) scientists.
April 2020 marked the 44th consecutive April and the 424th consecutive month with temperatures above the 20th-century average, but the average April temperature in north and central India was 1 to 2 degrees below average, according to NOAA .
The warmest April temperatures were recorded across northern Asia or the Siberian region where temperatures were 4 degrees C above average or higher. Other very warm areas include western Australia, central Europe, the Gulf of Mexico, the Labrador and Bering seas, parts of the northern and southern Pacific Ocean, and Antarctica. Temperatures of 2 degrees C below average were recorded across Canada and contiguous parts of US.
The average temperatures in the January to April period in India was also average to lower than average, according to NOAA.
“The atmospheric dynamics are not conducive in India for temperatures to pick up. Local factors are not enough for temperatures to rise. Large scale atmospheric dynamics also affect [temperatures]. We have had a very high western disturbance activity this year, which has caused clouding on many days and has reduced solar radiation. There has been cold air incursion from the north. There could be many reasons for this, including North Atlantic Oscillation or Arctic Oscillation or sea ice melting in the Arctic. We have to analyse these factors,” said M Rajeevan Nair, secretary, ministry of earth sciences. North Atlantic Oscillation is a fluctuation of atmospheric pressure over the North Atlantic Ocean that has a strong effect on winter weather in Europe, Greenland, northeastern North America, North Africa, and northern Asia.
Between March 1 and May 13, the pre-monsoon season, central India received 157% excess rains; northwest India received 39% excess rains; and the country as whole received 19% excess rains.
“Yes we had relatively cold January and February and then mild weather in March and April but this could also be linked to climate variability. Only if it is unusually cool or if mild weather continues for a few years can we probably link it to climate change,” said Krishna Achuta Rao, Professor, Centre for Atmospheric Sciences at IIT Delhi.
In April, the global land and ocean surface temperature was 1.06 degree C above the 20th-century average of 13.7 degree C. This was the second highest April temperature, only April 2016 was warmer by 1.13°C degree C. Sea ice coverage for April 2020 was 6.5% below the 1981–2010 average and the fourth-smallest April extent on record for the Arctic.
Meanwhile, a low pressure area over southeast Bay of Bengal and adjoining south Andaman Sea has become well marked. It is very likely to concentrate into a depression over central parts of south Bay of Bengal on May 15 and further intensify into a cyclonic storm, Amphan, over the same region by May 16, IMD said. The cyclone may make landfall on West Bengal coast or in the northeast, according to private weather forecasters.