What causes haze? Is it simply humidity, or pollution, or ? There seems to be a great deal of it in the summer, here in the US. Yesterday, leaving BHM there was a light layer that almost looked like an overcast cloud deck but it wasnt - and it had burned off by about the Atlanta area and from there up to BWI was clear with a very distinct view of the ground and small puffy clouds. Leaving BWI later that day, they had a light layer of haze but when we got to BHM it was extremely thick, blinding. But from the ground you could have good visibility of 8 -10 miles, but if you look up you can barely make out the shapes of the clouds from the haze. It was not cloudy/overcast, there was sun. Later when the sun set the haze was so thick that the sun was a massive red ball.
I've noticed that even from the ground, we seem to have this haze very often. I wonder if certain parts of the country have it more than others (well except for smog in L.A.)? Do people in other parts of the world have it this bad too?