Air quality deteriorates in Delhi due to reduction in wind speedUpdated: Jan 27, 2020, 23:58 IST
Air quality in Delhi deteriorated on Monday to “very poor” on the central pollution control board (CPCB) scale.
This is mainly due to a reduction in wind speed from over 20 kmph on January 23 to less than 10 kmph, the minimum windspeed required in Delhi to disperse pollutants.
“Northwesterly winds was very fast until January 25 night. Due to an approaching Western Disturbance (WD), wind direction changed to Easterly and there was light rain that only made pollutant dispersal more difficult. Pollution levels may reduce after it rains in parts of NCR tomorrow (Tuesday),” said Kuldeep Shrivastava, head, regional weather forecasting centre.
The CPCB’s air quality index (AQI) read 345 on Monday. It was 250 on January 25.
In its daily bulletin, the India Meteorological Department (IMD) on Monday said, “A fresh and active Western Disturbance is very likely to affect Western Himalayan region from Monday. It is very likely to cause fairly widespread to widespread rain/snow over Western Himalayan Region with isolated heavy rain/snow over Jammu & Kashmir and Himachal Pradesh on January 28 and over Uttarakhand on January 29.”
Widespread rain and thunderstorm is also likely from January 27 to 29 over Punjab, Haryana, Chandigarh, Delhi, Uttar Pradesh and isolated to scattered over Rajasthan, north Madhya Pradesh and parts of east India.
The approaching WD is the seventh in January. “On an average, there are three WDs in January,” said RK Jenamani, senior scientist at National Weather Forecasting Centre.
Ministry of earth sciences’ air quality early warning system said the air is likely to remain “poor” on Tuesday. It is likely to deteriorate marginally on Wednesday.
Rainfall in January is 70% above normal with 42% districts receiving large excess (60% or more than normal) rainfall including most parts of north and central India.Scattered to fairly widespread rain/thunderstorm over northwest India and northern plains is likely during next three days with peak activity on Tuesday. Dense fog is also likely over plains of northwest India during January 29 to 31.