Measurement and Scaling of Lake Surface Skin Temperatures

Water temperature microprofiles at the air-water interface of a stratified lake were measured concurrently with moderate wind speeds of 0.8-8.2 ms(-1) above the lake surface. The day-time measurements revealed the cool skin effect of water surface temperatures that triggers the cooling of the lake surface and the occurrence of natural convection. Natural convection velocity scale mediates the thickness of the diffusive thermal sublayer and the corresponding net heat flux at the interface. The diffusive thermal sublayer thickness ranged from 0.7 to 3.6 mm. The temperature microprofiles and proposed parameterization of skin-to-bulk temperatures enable similarity scaling of temperature microprofiles over the diffusive thermal sublayer thickness. The proposed parameterizations allow for the estimation of diffusive thermal sublayer thickness and skin-to-bulk temperature difference in the presence of natural convection. Our results have the potential to facilitate the validation and integration of satellite-derived lake surface temperatures.

Automated summary

This study measured water temperature microprofiles at the air-water interface of a stratified lake under moderate wind speeds. The measurements revealed the cool skin effect and occurrence of natural convection. Proposed parameterization methods allow for estimation of diffusive thermal sublayer thickness and skin-to-bulk temperature difference, facilitating the validation and integration of satellite-derived lake surface temperatures.