# title
On the ocean's upper boundary conditions in regions influenced by sea ice

# abstract
During recent years, studies with global ocean general circulation models (OGCMs) revealed strong dependencies of their performance on the way the impact of the atmosphere is prescribed, specifically how vigorously the upper ocean is tied to lower atmosphere conditions. The presence of sea ice introduces further complication to this prescription, due to its dynamic and thermodynamic characteristics, and due to its sensitive dependency on the ambient atmospheric and oceanic conditions. This study provides an overview over the highly nonlinear and interactive processes involved with sea ice modifying the upper boundary conditions for ocean models in polar regions. We address the physical representation of sea ice in present-day global OGCMs in comparison to regional state-of-the-art sea-ice models. We discuss the role of different external forcing fields, and various sea-ice forcing mechanisms considering the role of interactive boundary-layer processes. This discussion includes the nonlinear impact of subgrid-scale heterogeneities on the momentum forcing. Finally, the possible impact of sea ice on global ocean characteristics is discussed. Copyright  1996 Elsevier Science B.V. All rights reserved.