Effects of Cold Air Outbreaks on Evaporation and Heat Loss from Three Regions in the Gulf of Mexico

Abstract

Simultaneous hourly measurements of atmospheric pressure; wind speed; and air, sea-surface, and dew-point temperatures from three regions in the Gulf of Mexico in 1996 are incorporated in the analysis of sensible and latent heat fluxes and the evaporation rate from the Gulf to the atmosphere. The three regions included in the study are the deep western Gulf, the northern Gulf continental shelf break near De Soto Canyon, and the northern Gulf nearshore environment at Grand Isle, LA. After the case study of a severe cold air outbreak is presented, monthly variations of evaporation and heat fluxes are investigated. It is found that on an annual basis the sensible heat flux is nearly the same between the nearshore and the shelf break regions. For the latent heat flux, the northern shelf break and deep western Gulf are nearly equal and are higher than the northern nearshore region. Also, the evaporation rate and the rainfall amount are approximately in balance in the northern Gulf nearshore environment.