SEASONAL HEAT STORAGE IN THE NORTH ATLANTIC OCEAN

Abstract

The seasonal range in heat content of the upper two hundred meters of the water column has been calculated for latitude zones between 20N and 65N in the North Atlantic. The calculation was based on 20,000 bathythermograph observations. The average range in heat content from the end of January to the end of August for the entire area is 36 kg-cal per cm2. A maximum heat storage occurs in mid-latitude in an area just north of the mean position of the Gulf Stream. For comparison, the heat storage due to local heating was computed for the same area. Estimates of net radiation, evaporation and turbulent heat flux by Budyko (1955) were used for this purpose. The average change in heat content over the same period according to this calculation is 31 kg-cal per cm2. The results indicate that, for the Atlantic as a whole, seasonal changes in the transport of heat by ocean currents and/or seasonal changes in the exchange with deeper layers amplify heat storage near the surface at mid-latitudes but reduce it above 50N.