Author(s): Peng Lu; Zhijun Li
Keywords: No Keywords
Abstract: Many interesting characteristics of sea ice drift depends on the ratio of atmospheric drag coefficient (Ca) to oceanic drag coefficient (Cw), but a thorough discussion on this issue has not yet been done because of the imbalanced studies on Ca and Cw. Based on a new parameterization of sea ice oceanic drag coefficient, we found a way to gain an insight into this ratio. The dependences of Ca/Cw on the floe aspect ratio, ridging intensity, ridge sail/keel slope, and surface/bottom roughness were discussed, through the parameterizations on the atmospheric and oceanic drag coefficients of sea ice. The results reveals that Ca/Cw increases obviously with increasing ice concentration (A) for ice floes in the marginal ice zone, while remains at a steady level (0.2~0.25) for floes in the central ice zone. For varying surface/underside morphology, the ratio also increases with an increase in the ratio of surface skin friction drag coefficient (Cs′) to bottom skin friction drag coefficient (Cs), and the ratio of ridge sail form drag coefficient (Cr′) to ridge keel form drag coefficient (Cr). Moreover, the ratio Ca/Cw also changes with the floe aspect ratio and ridging intensity, which determine the dominance of ridge form drag and surface skin friction among the total drag forces.