A dust bowl in a trans-continental arc

...Delhi is cursed with poor geography as far as air pollution is concerned. The capital city lies to the north-east of the Thar Desert, to the north-west of the central plains and to the south-west of the Himalayas. As winds arrive from the coasts, bringing with them pollutants picked up along the way, they get ‘trapped’ right before the Himalayas. The air pressure pushes from one direction, and with the inability to escape quickly in the other, the particulate matter accumulates over the northern plains. This accumulation and entrapment affect not only Delhi, but the entire expanse between Punjab in the west to West Bengal in the east. Imagine this as a “bowl” that collects pollutants, with only a narrow outlet for it to escape...

...North India’s air suffers from similarly challenging topography. In fact, India happens to be in the middle of a large transcontinental “arc” with high particulate pollution. This “arc” is the mass of land with high air pollution levels starting from Mauritania, Algeria, and Mali in the north-west of Africa, right up to China on the east of Asia. Countries in between this vast geographical landscape—including Libya, Egypt, Saudi Arabia, Iran, Afghanistan, Pakistan, and India—all have high particulate pollution.