[Duck From NY]

Originally Posted by Guiltyspark

The sky in Korea and China always looks so gray. I assume massive pollution from northern China is to blame.

I don't think visible smog would be able to pass over the ocean water of the Yellow Sea.

Greater Seoul is one of the largest metros in the world, and it's mostly surrounded by mountains to the North, East, and South. The prevailing winds come from the West, so I imagine they have a situation similar to L.A. where the emissions they produce get bottle necked in to the valleys. From what I understand, though, they are rapidly pushing to reverse the problem with additional green space and low-emission buses.