Time series analysis of SMMR and SSM/I data for climate change detection

Sea ice is a sensitive component of the climate system, such that reductions in the Arctic and Antarctic sea ice covers could be indicative of greenhouse warming. The most consistent source of information on sea ice parameters is microwave remote sensing from polar-orbiting satellites. Previous analyses of Scanning Multichannel Microwave Radiometer (SMMR) data from 1978-87 revealed a significant decrease in Arctic sea ice extent with no changes in the Antarctic. The authors extend the record to 1994 by including data from the subsequent Special Sensor Microwave Imager (SSM/I). This involves intercalibrating the SMMR-SSM/I data during their six-week overlap period, achieved at the sea ice concentration level using the NORSEX algorithm. Time series analysis of the merged 1978-94 continuous sea ice time series reveals continued decreases in Arctic ice extent and area. Moreover, the authors find a slight decrease in Antarctic ice extent during the period. The brevity of the records reiterates the need for longer, continuous microwave time series to identify long-term trends