Adding further greenhouse gases to the atmosphere warms the ocean cool skin layer, which in turn reduces the amount of heat flowing out of the ocean. (skepticalscience.com)
So the mechanism should cause a decline in skin temperature gradients with increased cloud cover (more downward heat radiation), and there should also be a decline in the difference between cool skin layer and ocean bulk temperatures - as less heat escapes the ocean under increased atmospheric warming. (skepticalscience.com)
Conduction from atmosphere to ocean is not the only (and I suspect not even the primary) manner by which energy transfers from the atmosphere into the ocean cool skin layer. (skepticalscience.com)