Mahesh Palawat, Skymet Weather's vice president of meteorology and climate change, tweeted today that Delhi is cooler at 4.4 degrees than Shimal at 5.4 degrees. The reason for this could be the clear skies over Delhi and the partly cloudy skies over Shimla. He went on to say that during the night, the energy emitted by the Earth is caught between the cloud and the earth. He further said that this is referred to as the Greenhouse Effect.
He wrote, “At 4.4 degree #Delhi in colder than #Shimal 5.4 degree. Reason may be clear skies over Delhi and partly cloudy sky over Shimla. Energy released by #Earth during night get trapped between cloud and earth. Known as #Greenhouse effect. #HimachalPradesh @SkymetWeather @JATINSKYMET”
At 4.4 degree #Delhi in colder than #Shimal 5.4 degree. Reason may be clear skies over Delhi and partly cloudy sky over Shimla. Energy released by #Earth during night get trapped between cloud and earth. Known as #Greenhouse effect. #HimachalPradesh @SkymetWeather @JATINSKYMET— Mahesh Palawat (@Mpalawat) December 22, 2021
The cold wave in Delhi eased marginally on Wednesday as freezing northwesterly winds slowed under the impact of a Western Disturbance sweeping northwest India. The minimum temperature at the Safdarjung Observatory, which serves as the city's official thermometer, was 4.4 degrees Celsius. On Monday and Tuesday, the observatory recorded a cold wave, with minimum temperatures of 3.2 degrees Celsius and 4 degrees Celsius, respectively. Minimum temperatures were 7.6 degrees Celsius, 4.2 degrees Celsius, 6.7 degrees Celsius, and 4.8 degrees Celsius at Palam, Lodhi Road, Ridge, and Ayanagar, respectively. If the minimum temperature in the plains falls below 4 degrees Celsius, the IMD announces a cold wave. When the minimum temperature falls below 10 degrees Celsius and is 4.5 degrees below average, a cold wave is declared.
Under the influence of two back-to-back western disturbances in northwest India, the temperature is expected to rise up to eight degrees Celsius by the weekend, according to an official with the India Meteorological Department. At 9 a.m., the capital's air quality index (AQI) was 399. On Tuesday, air pollution levels in the national capital had risen to the 'severe' category, with the 24-hour average AQI reading 402, a day after the Centre's air quality council eased construction and demolition restrictions in Delhi-NCR. According to weather experts, 'very poor' to 'severe' air quality is expected till December 27.