Is Delhi the PRIMARY source for Chennai Smog? Physics says NO
The plume picture has sparked a debate saying Delhi's bad air has traveled to Chennai resulting in Chennai smog. Well, well, well, pictures without physics based explanation are extremely dangerous and some weather bloggers are proving their point simply using the images. Here, I try to explain the physics (in my capacity from what I know about fluid dynamics and thermodynamics). Before that, let us lay downs some facts. Fact : Chennai is reeling under a smog. No doubt about it. Some people are diverting the debate to smog vs fog. Realise that smog is nothing but smoke+fog . So, fog is indeed a part and parcel of smog. The smoke particles get attached to the misty fog. Even if the fog goes away (due to solar convection), the smoke can hang around like a haze or drop down to ground levels (resulting in irritation and pollution to your face - when you wipe down, you will see brown or black dust). But it is a cycle, where fog will again form due to dew point concept. S