Abstract
From in-situ meteorological and ice observation in early February of 1996 and 1997, we estimate the heat budget in the ice cover of the southern Okhotsk Sea. Ice concentration and ice thickness distribution required for its calculation are obtained quantitatively from video analysis. One dimensional-thermodynamical model is used to calculate heat flux. The total heat flux is obtained by summing up the areally weighted heat flux on each ice thickness. As a result, the following characteristics are found in this region. (1) Due to relatively thin ice thickness, turbulent heat flux (sensible+latent) is upward, showing that the sea ice region gives turbulent heat to atmosphere. (2) Thin ice and open area contribute significantly to the total turbulent heat flux over the whole area. (3) Thermodynamical ice growth is limited to below 1cm per day on average. The first and third results are the characteristics of this area located at a relatively low latitude, while the second one is generally observed for polar regions. The results also suggest that surface melting occur at daytime mainly due to solar radiation. The salinity of sea ice samples shows the values lower than that of the first-year ice in the polar regions and rather similar to that of the multi-year ice, which is lowered by surface melting during summer; this may support this suggestion.
