Wet and dry surfaces

[nadia86]

Imagine two adjacent playing fields one with a wet and the other with a dry surface. If you simultaneously measured air temp above each surface on a summy afternoon where would you expect to find the higher temp. Why?

[Mortartube]

I would suggest above the wet one. Evaporation has a cooling effect on the surface being evaporated from. Therefore the evaporate in the airspace above the wet field would be carrying heat away from the surface of the field. This is just an educated guess.

[newtron]

The dry surface would have the higher temperature above it. As Mortatube said, evaporation has a cooling effect, but the heat is not being carried away. it is being used as energy to change the the liquid water to water vapor. This energy (heat) is most likely coming from the sun's radiation on the surface.

http://en.wikipedia.org/wiki/Latent_heat