Delhi Pollution has been in the hazardous /severe category most of the time Since beginning of November. Although there was marginal relief in between and AQI index came down to a very poor category, even then, air quality index has been bad over Delhi and NCR.
The smoke from stubble burning from Punjab and Haryana was at its peak during last 4 to 5 days. This year, withdrawal of monsoon commenced late and Southwest monsoon continued upto mid October. Therefore, the farmers of Punjab Haryana and West Uttar Pradesh did not have enough time to dispose the stubble. That is the reason farmers got a very small window for disposing the stubble, which was its peak.
Another important factor was the weather condition after withdrawal of Monsoon. North westerly winds commenced, which carried the smoke of stubble burning from Punjab and Haryana towards Delhi and NCR and wind speed remained on lower side.
Therefore, the smoke from stubble Burning was carried to Delhi and NCR. In the absence of strong winds it persisted over national capital and was not dispersed to wider area.
Now winds are from easterly and south easterly direction and speed is a very low therefore we do not expect any significant improvement in pollution levels. There are mild chances of light rain on November 20 over parts of South Haryana, Southwest Uttar Pradesh and Delhi but this light rain cannot wash away the pollutants, which is why pollution levels are expected to persist.
Wind speed may pickup pace once again from November 21 or 22nd. During that time northwesterly moderate winds may give marginal relief, but significant relief is not expected until winds are continuous and rains are lashing the region. Thus, significant relief is not expected from the high pollution levels.
