The Climate Machine: Tropical vs Midlatitude Clouds


Tropical Low Clouds

Tropical low clouds do little to change OLR since the tropical atmosphere is already optically thick. Also, they do not significantly alter greatly surface downwelling longwave radiation. 

Thus they have little longwave impact at the surface or TOA. However, they do reflect sunlight. Since the longwave and shortwave impact of tropical low clouds do not offset each other, they play a particularly important role in cooling the planet.

Midlatitude and Polar Low Clouds

Midlatitude and polar low clouds lead to surface warming

They lead to significantly more downwelling longwave radiation hitting the surface and thus warm the surface. They also reduce OLR and reflect sunlight. Thus, they have both a global warming (longwave) and cooling (solar) effect.

 

If global warming were to lead to more low clouds in the tropics how would this feedback on the Earth system. Would an increase in low clouds in midlatitudes have as strong of an impact?



Also, examine the differences in how low and high clouds impact climate.