Complex interactions between the ocean, atmosphere, sea ice, and floating glacial ice sheets in the Weddell Sea lead to surface waters becoming cooler, saltier, and therefore denser. The dense water sinks, carrying surface-acquired properties such as O₂ and CO₂ into the deep ocean where they are distributed throughout the world ocean. This process is called "ventilation" and plays a major role in the coupled global ocean and atmosphere. Any modification of the sea ice distribution by oceanic or atmospheric forcing is also relevant to climate modeling because the reflectivity of ice is much greater than open water, thus more ice implies much greater reflection rather than absorption of incoming solar radiation.

The most vigorous cooling and salinization of surface water occur over the continental shelf and under the ice shelves around the perimeter of the Weddell Sea. Many processes help to modify the surface water, and determine the final property of the modified water as it sinks down the continental slope. Tides play a role in this system, both directly and through interactions with other components of the atmosphere-ocean-ice (AOI) environment. Some of the mechanisms that are of interest to us are as follows.

• Tidal currents create turbulent mixing in the ocean, at the seabed, at the base of the ice, and in the stratified ocean interior.
• Tidal currents modify sea ice properties and distribution by (a) increased upper ocean mixing (mixing brings subsurface warm water up to where it can melt ice) and (b) through the dynamical effect of tide-induced ocean stress on the ice base. This process also modifies the heat exchange rate between the ocean and atmosphere.
• Tidal stirring under the ice shelves helps to melt the base of the shelves.
• Tidal strain on the shelf ice helps to create the rifts that eventually form the detachment points for new icebergs.

For these reasons, we have been funded to carry out several studies to improve our understanding of the distribution of tidal energy in the Weddell and Scotia Seas, and to investigate the effects of tides on other processes. Our studies to date fall into two categories: improving numerical models that predict tidal energy distribution; and using the models to understand the role of tides in the large-scale circulation of the Weddell Sea and its cover of sea ice. Future funded work includes a detailed study of the interactions of ocean tides with the glacial ice shelves. More information on specific projects can be found by following the links below.

• A Barotropic Ocean Tides Model of the Southern Ocean and Antarctic Seas
  
• A Barotropic Ocean Tides Model of the Weddell and Scotia Seas


• A Baroclinic Ocean Tides Model for the Southern Weddell Sea


• Tidal Forcing of Ice Motion and Divergence in the Southern Weddell Sea


• Analysis of Sub-Ice-Shelf Tides in the Weddell Sea Using SAR Interferometry
• Future Work