Air quality dips due to poor wind speed

New Delhi: Delhi’s air quality deteriorated marginally on Saturday and settled in the poor category from moderate on Friday.

Central Pollution Control Board (CPCB) data showed Delhi’s overall AQI on Saturday at 231. On Friday, the air quality had improved to reach 137. IMD scientists said that the wind speed had slowed down slightly on Saturday compared to Friday, but it was still enough to have facilitated pollution dispersion.

VK Soni, head of IMD’s environment monitoring research centre, said the average wind speed during the day remained around 8-10kmph. On Friday, however, the wind speed had peaked to around 15 kmph during the day and on Thursday night too the wind speed was high.

“The average wind speed recorded on Thursday night was also around 8kmph, which is rare because winds tend to slow down at night. During the day too, the winds have been favourable for the dispersion of pollutants. Today (Saturday), the wind speed was high but not as high as it was on Friday, thus the increased AQI,” Soni said.

Union ministry of earth sciences’ air quality monitoring centre, System of Air Quality and Weather Forecasting and Research (Safar), data shows that on Friday 499 fires were spotted over Punjab and Haryana, and its contribution to the Capital’s PM 2.5 levels was around 4%.

Soni also said that the air quality is expected to remain between moderate and poor range till November 30, after which there is a forecast for deterioration.

Kuldeep Srivastava, head of IMD’s regional weather forecasting centre, also said that gradually wind speed will deteriorate from Sunday.

“Over the last few days because of the impact of a western disturbance over the hills, the winds have picked up speed, but it will slow down again,” he said.

Srivastava said that the temperature in Delhi and NCR is also expected to fall in the coming days because of the continuing snowfall in the regions of Jammu and Kashmir, Himachal Pradesh, Ladakh and parts of Uttarakhand.

On Friday, the minimum temperature recorded at the Safdarjung observatory, which is considered the official recording for the city, was 10.1 degree Celsius. The maximum temperature was 26.4 degree Celsius.

“The normal minimum temperature for the first week of December is around 9-9.5 degrees Celsius. We are expecting the temperature this time to be a couple of degrees lower. From November 30, the minimum is likely to be around 7-8 degrees Celsius,” Srivastava said.