S.A.J. Shirazi
Winter in sprawling Lahore spells horror for thousands of residents. Not because of cold but due to the phenomenon of smog. Let your gaze roam over the cityscape while standing on top of the Yadgar-e-Pakistan and one finds how the skyline of the minarets and domes looks dark and sad against the clouds of thick smog.
The fog is triggered by temperature inversion – the formation of a static layer of cooler air close to the ground as the nighttime temperature drops. Normally, air closer to the ground is warmer than the air above it, and therefore rises. Inversions are frequent on winter nights after the ground has cooled down so much that it begins to chill the air closest to it often causing mist to form as water vapor precipitates on dust particles. Normally the morning sun swiftly breaks through the mist and heats the ground, which warms the air above it, breaking the inversion.



























































