Satellite Evidence for an Arctic Sea Ice Cover in Transformation.
Recent research using microwave satellite remote sensing data has established that there has been a reduction of about 3 percent per decade in the areal extent of the Arctic sea ice cover since 1978, although it is unknown whether the nature of the perennial ice pack has changed. These data were used to quantify changes in the ice cover's composition, revealing a substantial reduction of about 14 percent in the area of multiyear ice in winter during the period from 1978 to 1998. There also appears to be a strong correlation between the area of multiyear ice and the spatially averaged thickness of the perennial ice pack, which suggests that the satellite-derived areal decreases represent substantial rather than only peripheral changes. If this apparent transformation continues, it may lead to a markedly different ice regime in the Arctic, altering heat and mass exchanges as well as ocean stratification.
Johannessen
OM
Nansen Environmental and Remote Sensing Center, Edvard Griegsvei 3a, 5059 Bergen, Norway. Geophysical Institute, University of Bergen, 5007 Bergen, Norway. Nansen International Environmental and Remote Sensing Center, Korpusnaya ulitsa 18, 197110 St. Petersburg, Russia. Department of Geography, University of Bergen, Breiviksveien 40, 5045 Bergen, Norway.
Shalina
EV
Miles
MW