The Seasonality of the Heat Budget on the Ross Sea Continental Shelf in a Coupled Regional Ocean-Sea Ice-Ice Shelf Model

The Heat Content (HC) of water masses on the Ross Sea continental shelf plays an important role in regulating the circulations and the basal melting of the Ross Ice Shelf (RIS). Yet, the evolution of the HC on the Ross Sea continental shelf is still not clear due to the sparsity of observation. By employing a coupled regional ocean-sea ice-ice shelf model for the Ross Sea, this study analyzes the heat budget of water masses over the continental shelf and in the RIS cavity. According to the topographic features and the HC density, the continental shelf region has been divided into seventeen subdomains. The heat budget of the middle layer for every subdomain has been analyzed. In addition, the heat budget for the RIS cavity is assessed for the first time. Owing to Modified Circumpolar Deep Water intrusion, water masses over the eastern shelf are warmer than over the western shelf, with the coldest water identified in the southwestern inner shelf. The horizontal heat flux mainly provides heat to the continental shelf, while the atmospheric forcing tends to warm up the ocean during the ice-melting period and cool down the ocean during the ice-freezing period. The vertical heat flux is generally upward and transports heat from the deep layer to the upper layer. In the RIS cavity, the seasonal cycle of the HC is dominated by the horizontal flux across the RIS front rather than the basal thermal forcing of the RIS.