New Delhi
A steep rise in mean temperatures have been recorded across all seasons since 1996 onwards over India with the sharpest rising trend recorded in the pre-monsoon season, shows India Meteorological Department’s latest offering—Climate Data Service Portal.
The data highlights the impact of climate change on India’s mean temperature trends.
The portal launched on Tuesday on the occasion of World Meteorological Day has real time visualisation of meteorological data from across the country; climatological tables; visualisation of historical meteorological data including of monsoon rainfall pattern; mean temperature rise; frequency of cyclones etc.
According to IMD, the CDSP will help researchers and the government in climate change studies; planning and mitigation strategies; early warning to people etc. Statistical analysis of meteorological data in the portal is still under development.
CDSP also offers climatological data for each station. For example, for Safdarjung station, the mean maximum temperature from 1981 to 2010 has been 35.3 degree C and the highest temperature recorded in March at the station was 40.6 degree C on March 31, 1945. The mean wet bulb temperature recorded in June at 5.30 PM is 25.4 degree C; 27 degree C in July and 26.9 degree C in August—the three monsoon months.
Wet bulb temperature is the lowest temperature to which air can be cooled by the evaporation of water into the air at a constant pressure. It is therefore measured by wrapping a wet wick around the bulb of a thermometer and the measured temperature corresponds to the wet bulb temperature according to a paper in Science Direct.
{{/usCountry}}Wet bulb temperature is the lowest temperature to which air can be cooled by the evaporation of water into the air at a constant pressure. It is therefore measured by wrapping a wet wick around the bulb of a thermometer and the measured temperature corresponds to the wet bulb temperature according to a paper in Science Direct.
{{/usCountry}}A paper titled “The emergence of heat and humidity too severe for human tolerance” published in May 2020 said when it’s very hot and humidity is also extremely high, evaporation slows down and eventually stops. That point comes when the so-called the wet-bulb temperature reaches 35 degrees Celsius (95 degrees Fahrenheit).
IMD’s theme for World Meteorological Day was “Oceans, Our Climate and Weather’ with scientists highlighting the Ocean’s impact on weather and climate especially during the El-Nino and La-Nina phases. The Ocean is also a major driver of the global economy, carrying more than 90% of world trade and sustaining the 40% of humanity that lives within 100 km of the coast.
“Oceans absorb the greatest amount of solar radiation over 90%, the earth’s surface absorbs on 2.3% rest is absorbed by glaciers and other surfaces. So, you can imagine the impact of oceans on meteorology. ENSO episodes for example have a profound impact on weather conditions in US, India and many parts of the world,” said M Mohapatra, director general, IMD.
El Niño and the Southern Oscillation (ENSO) is a periodic fluctuation in sea surface temperature and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean according to the National Oceanic and Atmospheric Administration (NOAA).
ENSO has a major influence on weather and climate patterns such as heavy rains, floods and drought. El Niño has a warming influence on global temperatures, whilst La Niña has the opposite effect. In India for example, El Nino is associated with drought or weak monsoon while La Nina is associated with strong monsoon and above average rains and colder winters.