On Thursday, January 17, 2013 9:52:46 AM UTC, Freddie wrote:
There are two kinds of fog, radiation and advection.

What about sea fog?

Most sea fog is advection fog. Warm moist air runs over cool sea whose

surface temperature is below the dewpoint temperature of the air.

Thanks for that, but it seems not to explain the sharp edges that North

Sea fog has on occasion

That is due to very small variations in sea surface temperature or low-level

humidity

or the isolated but regular days when radiation fog over south Dorset

drifts out over Lyme Bay and not only becomes sea fog but expands its area

when clear of the coast.

This is advection fog - moist air moving out to sea. Probably expanding due

to further evaporation of moisture from the sea surface.


Thanks. It has always intrigued me why the fog does not disperse in winter when moving over sea temperatures that are higher than the land, but I have noticed it persist for two or three days; a number of times over the last few years.