Classification of new-ice in the Greenland Sea using Satellite SSM/I radiometer and SeaWinds scatterometer data and comparison with ice model

In the ice covered waters of the Greenland Sea the polarisation ratio of QuikSCAT SeaWinds Ku-band (13.4 GHz) scatterometer measurements and the polarisation ratio of DMSP-SSM/I 19 GHz radiometer measurements are used in combination to classify new-ice and mature ice. In particular, the formation of the new-(frazil/pancake)-ice ‘Odden’ (8° W, 75° N) March 11th–18th, 2001, is used in the study. The results of the ice cover classification in the Greenland Sea are compared to model parameters from a sea ice model. The classification of each ice pixel is performed using its backscatter and radiative properties as reflected in the polarisation ratio. Our results based on these comparisons show that the transformation into older mature (sheet) ice occurs within 5–10 days. During one day the new-ice cover increased by 33 000 km2. The new-ice appears in March 2001 as a peninsula (maximum extent 56 000 km2) appended to the belt of older ice drifting along the East Coast of Greenland. These results are consistent with the ice model and with Radarsat images. Furthermore, using the ice model it is demonstrated that the new-ice/mature ice threshold in the classification corresponds to the physical transition of the ice cover from pancake ice to a consolidated young-ice sheet. The classification of each pixel into ice or water is done using two scatterometer parameters, namely the polarisation ratio and the daily standard deviation of the backscatter.