COMPARISON OF PASSIVE MICROWAVE SEA ICE ALGORITHMS FOR DETECTING THE TREND OF GLOBAL WARMING

摘要

The passive microwave sensors on board satellite allow us to monitor the distribution of sea ice on global basis. In this study, two passive microwave sea ice algorithms, namely NASA Team algorithm and Bootstrap algorithms, were compared to examine their difference on detecting the trend of total sea ice area in the Arctic and the Sea of Okhotsk. The analysis was performed for the time frame of 1978 to 2004 using SMMR and SSM/I data. The decrease trend of the total sea ice cover and averaged ice concentration of the Arctic and the Sea of Okhotsk were observed in both algorithms. The difference of the both algorithms was rather small for the total Arctic, but was rather large for the Sea of Okhotsk. The authors have compared a SSM/I sea ice concentration image with a MODIS image taken on the same day for the Sea of Okhotsk, and examined the difference of the algorithms in details.