E. Bjorgo et al., ANALYSIS OF MERGED SMMR-SSMI TIME-SERIES OF ARCTIC AND ANTARCTIC SEA-ICE PARAMETERS 1978-1995, Geophysical research letters, 24(4), 1997, pp. 413-416
The most consistent means of investigating the global sea ice cover is
by satellite passive microwave sensors, as these are independent of i
llumination and cloud cover. The Nimbus 7 Scanning Multichannel. Micro
wave Radiometer (SMMR) and the Defense Meteorological Satellite Progra
m (DMSP) Special Sensor Microwave Imager (SSMI) provide information on
the global sea ice cover from 1978 to present. The two instruments fl
ew simultaneously during a 6-week overlap period in July and August 19
87, thus enabling intercomparison of the two sensors. Brightness tempe
ratures are corrected for instrument drift and calibration differences
in order to produce continuous time series of monthly averaged Arctic
and Antarctic sea ice extent and sea ice area through the use of the
NOr-wegian Remote Sensing EXperiment (NORSEX) algorithm, which relates
brightness temperatures to ice concentration. Statistical analysis on
the time series estimates the decreases in Arctic ice extent and ice
area to be 4.5% and 5.7%, respectively, during the 16.8-year observati
on period. The overall trends established here serve to better define
and strengthen earlier assertions of a reduced ice cover, based on ana
lysis of SMMR and SSMI data taken separately. These results are consis
tent with GCM simulations that suggest retreat of the sea ice cover un
der global warming scenarios.