I remember at CLK we had a beautiful day,wind was calm you could see for miles and even Macau.
Then a northerly wind picked up.You could see a wall of brown shi
y soup rolling in,just like a North Sea fog or harr.With 10 minutes we were 900 m IRVR,and the sky was Chinese grey/green.
I think the some of the polution in town is caused by traffic,and is trapped in the bowl.The majority of it is imported from the Mainland.