Evaluation of Sea Ice Motion in the Western Ross Sea Using AVHRR Imagery

摘要

It has been shown that in regions not influenced by coastal effects, sea ice moves primarily in response to the wind. Researchers working in the Arctic have found that nearly 70% of the variance of ice motion can be explained by the geostrophic wind alone. A relationship between geostrophic wind, surface wind, and sea ice motion in the southwestern portion of the Ross Sea is examined here. Sea ice motion is obtained from applying a Maximum Cross Correlation (MCC) routine to two Advanced Very High Resolution Radiometer (AVHRR) scenes temporally separated by twenty-four hours. This motion is then compared with geostrophic and surface winds acquired from the National Centers for Environmental Prediction (NCEP) Medium Range Forecast (MRF) model, as well as Automatic Weather Station (AWS) surface winds. An attempt is made to support the results obtained by Thorndike and Colony in regions not dominated by coastal effects. It is found that in the southwestern Ross Sea, the ice motion tends to deviate from previous findings. In the coastal regions, this deviation is attributed to the strong katabatic winds flowing down from the Antarctica Plateau. In the regions away from the coast, other forces such as internal and hydrodynamic stresses may have caused the discrepancy.