Air pollution in the Delhi-NCR region has been an alarming problem over the years. The pollution levels drastically increase during winter, covering the city with dense smog. In a new finding by NASA, a cause of this problem has been identified. Photos tweeted by The Weather Channel India show that stubble burning activities in neighbouring states partly cause the pollution to spike in this region. Satellite images captured by NASA depict stubble plumes gushing from these states towards Delhi-NCR. The photo caption read, "Every winter, Delhi pollution spikes drastically, partly due to the stubble burning activities in neighbouring states. Now, NASA has captured satellite images depicting stubble plumes gushing towards Delhi."
The Weather Channel India has explained the process of stubble burning. Farmers usually torch their crop residues to prepare the fields for the next season. The tweet read, "This annual activity leads to the exacerbation of recurring seasonal pollution."
The images captured by NASA depict a "river of smoke" emerging from crop residues torched in Punjab and Haryana. This stretches towards Delhi.
Often, the spike in air pollution is also attributed to fewer air currents during this season. However, this year's lingering monsoon helped to control the increase in pollution levels at the start of November. But the pollution spiked thereafter. NASA has identified more than 74,000 fire hotspots in Punjab till November 16.
Pawan Gupta, a USRA scientist at NASA's Marshall Space Flight Center, talked about the pollution levels on November 11. He said, "A conservative estimate is that at least 22 million people were affected by smoke on this one day."
The stubble burning processes spike up during winter and hence add up to the pollution.
The tweet thread explained that the drop in temperature and lack of winds during the winter months cause the air pollutants to stay trapped in the atmosphere for longer periods. Ultimately, it leads to various health hazards.
Delhi's pollution has become a concerning issue this year too.