Delhi’s air quality in moderate category, mercury expected to settle around 41°C
The mercury touched 40.2°C at 2.30 pm on Monday in Safdarjung, the base weather station, at a time when humidity was at 45%, taking the heat index, or real feel, to 52°C, the highest so far this year
Delhi’s air quality was in the moderate category on Friday morning as the mercury was expected to settle around 41 degree Celsius on Tuesday.
Moist east wind raised humidity levels in the Capital on Monday. Combined with temperatures of over 40°C made most locations unbearably sultry. The mercury touched 40.2°C at 2.30 pm on Monday in Safdarjung, the base weather station, when humidity was at 45%, taking the heat index, or real feel, to 52°C, the highest so far this year.
Delhi’s wet-bulb temperature was 32.11°C on Sunday, also the highest so far for the Capital this year. Both these measures are likely to remain high. Relief is expected from June 30. The minimum temperature on Tuesday is expected to be 31 degrees Celsius.
According to Central Pollution Control Board, the hourly air quality index (AQI) was 126 at 9 am on Tuesday. An AQI between zero and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’, and 401 and 500 ‘severe’.
On Monday, the monitoring agency System of Air Quality and Weather Forecasting and Research said AQI indicates ‘moderate’ air quality with PM10 as the primary pollutant. “Dust (size > 2.5 micrometer) contributes ~ 60% to PM10. For the next 3 days (28th, 29th, 30th) peak wind speed is likely to be ~ 18-20 km/h causing moderate dispersion and AQI is likely to be within ‘moderate’. Moderate temperature (~ 39-40 deg C) and mixing layer height (~ 2.5-3.0 km) maintains moderate ventilation by convection improving air quality.”
