Water absorbs much more solar radiation than land.
...water, especially large bodies of water like a lake or ocean, are able to absorb more energy than land without warming.
...It is important to remember that the air is not heated directly from above by the sun. In fact, most of the incoming solar energy actually passes right through the atmosphere. However, as the land absorbs this energy, heat is radiated back into the atmosphere (from the earth), warming the overlying air. Some of this heat is transported to higher levels in the atmosphere through convection.
On the other hand, since the temperature of the water remains relatively constant throughout the day, the air over the water is not heated from below (as over land), resulting in lower air temperatures over the water.
http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/fw/sea/htg.rxml
And I am amused by how your second paragraph is self-contradictory. You say water both absorbs less radiation and more radiation. LMAO!
Edited by Alferd Packer at 12:28:44 on 04/07/17