Heat Flux and Ocean Surface Skin Temperature

The temperature of the ocean right at the surface is usually a few tenths of a degree Celsius (0.2 to 0.5 °C) cooler than the bulk temperature just a millimeter below the surface. Even though the difference is small, on a global scale the effect is important for estimating the uptake of CO2 by the ocean. This so-called "cool skin effect" is due to the typical conditions of cooling at the surface that results in a net flow of heat from the ocean to the atmosphere. The amount of the cooling depends on the magnitude of this net upward heat flux as well as the wind speed. We will install instrumentation at the top of the mast to measure the parameters necessary to study this effect. A weather station will measure wind, air temperature, relative humidity, and downward shortwave (solar) and longwave (clouds) radiation from the sky. The skin temperature will be measured using an infrared thermometer and the near-surface bulk temperature will be measured by a trailing thermistor known as a "sea snake". Since most measurements of the cool skin effect have been made in the open ocean, this is an unprecedented opportunity to study the cool skin in the coastal zone.