Why do isotherms vary more over land than over the ocean?

Answer 1

very simple, land had widely different albedo's.
this is the amount of energy which is absorbed and re-emitted as heat. The ocean has a fairly constant albedo, where as on land you have different coloured rocks, which have different albedo's.
Trees, grass, black soil, all have different albedo's. This varying amount of energy gives rise to different amounts of convective heating of the air above it.

Every try walking from grass onto a sandy beach on a sunny day? well then you have first hand experience of the difference in absorbed energy and albedo.

do a web search for albedo, here is the wiki entry for it
http://en.wikipedia.org/wiki/Albedo

Answer 2

I would have to take issue with a few answers above. It is not that the ocean doesn't have significant differences in surface temperature, or albedo either. The fact is that these differences are spread out across ocean basins. On land you can go from desert to mountains in a few km, then back. For most of the ocean, the surface properties vary slowly. But, atmospheric isotherms over the separation regions of western boundary currents (Kuroshiro, Gulf Stream) are highly variable, so it is not the case everywhere.

It is correct that many terrestrial surfaces convert solar radiation to returned infrared far more efficiently than salt water. But the albedo of Northern Siberia is not much different than the Arctic ocean, so it is incorrect to characterize the whole ocean one way, and all land another.

Answer 3

simply put it is the radiative properties of land and ocean. Land acts as black body radiating energy back into the atmosphere more quickly than water, this means quicker warming, and less abillity to sustain constant temperatures

Answer 4

The Ocean water temp is more constant than land...

Answer 5

Because there are greater temperature differences over land than over sea.

Answer 6

Water and moisture are good stabalizers of temperature. That is why in arid, dry areas like deserts, you can get very hot days, and chilly nights.

Answer 7

temp