Measurement and Scaling of Lake Surface Skin Temperatures

Abstract

Inland water and ocean surface temperatures are a “global thermometer” of the planet. These water surface temperatures provide an important coupling channel between aquatic and atmosphere environments and mediate the exchange of energy and chemicals between the two. We measured and analyzed temperature profiles in the proximity of air-water interface in a small stratified lake. These measurements revealed a “cool skin” effect – colder water temperatures at the lake surface than those just below it. This cool skin effect triggers the convective cooling of the subsurface water. We propose a model to quantify the cool skin effect in the presence of natural convection. The proposed model can potentially facilitate verification and integration of large-scale measurements of satellite-derived surface water temperatures and may assist the estimation of greenhouse gas transport across lake and ocean surfaces.