Area of a polynya at Amery Ice Shelf derived from AMSR-E 89 GHz sea ice concentrations and MODIS images

Polynyas are persistent openings and/or thin ice in the ice cover. They play an important role in the air-sea interaction. Their accurate detection, including an estimate of shape and area, is therefore important. There is a polynya at the front of the Amery Ice Shelf (AIS). In this paper, a threshold of 70% of AMSR-E sea ice concentrations is selected to define a polynya and to calculate the area. In addition, the polynya is recognized from cloud free MODIS images. Comparing the area obtained from two different methods, a polynya is well simulated from AMSR-E sea ice concentration data and the correlation is 85%. This supplies another way to analyse the small polynya at the front of the AIS, including characteristics and interannual variability of area of this polynya, especially in winter when MODIS data can not be used.