Ocean Heat and Seasonal Sea Ice Thickness in the Southern Ocean

Abstract

Typical values of the winter air-sea ice heat flux in the seasonal sea ice region of the Weddell Sea imply that the observed thermodynamic sea ice thickness in the region is much thinner than that expected in the absence of ice divergence or ocean sensible heat flux. Therefore, the ice must be dynamically thinned by ice divergence and/or by the presence of an ocean sensible heat flux which reduces the latent heat loss component of the air-sea heat flux and thus reduces the amount of ice growth. For an average air-sea heat flux of 35 W/m2 over ~5 months of the winter ice covered cooling period, the amount of ice thinned must be ~1.6 m.