HEAT BUDGET OF THE BARENTS SEA SURFACE IN WINTER

Variability of the total heat balance (HB) of the Barents Sea during the cold period of the year has been studied. The cold period is that of cooling of the sea surface when the heat flux is permanently oriented towards the atmosphere. The contribution of two major components of the HB, i. e. sensible and latent heat fluxes, to the observed increase of the total winter heat transfer at the sea-atmosphere interface has been estimated. Data on short-wave and long-wave radiation fluxes, and sensible and latent heat values were obtained from the atmos-pheric reanalysis of the European Center for Medium-term Weather Forecasting ERA5. HB of the sea surface was calculated as a sum of short-wave and long-wave radiation fluxes and those of sensible and latent heat. The total HB, as well as the total flux of sensible and latent heat for the cold period were calculated by summing up the corresponding values between the start and end dates of the cooling season. Calculations demonstrated an increase in the sum of HB over the cold season for the northern part of the Barents Sea (up to 2000 MJ/m2 over 40 years), and a decrease in the southern part of the sea (up to 1000 MJ/m2 over 40 years). In the northern part of the sea, the contribution of sensible and latent heat fluxes decreases to 0,3-0,4. The observed trend of sum of HB over the cold season and its turbulent components could with high probability be explained by increasing difference between air temperature and sea surface temperature.