Satellite Evidence for an Arctic Sea Ice Cover in Transformation
Ola M. Johannessen,
12*
Elena V. Shalina,
3
Martin W. Miles
14
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.
1 Nansen Environmental and Remote Sensing
Center, Edvard Griegsvei 3a, 5059 Bergen, Norway.
2 Geophysical Institute, University of Bergen, 5007 Bergen, Norway.
3 Nansen International Environmental
and Remote Sensing Center, Korpusnaya ulitsa 18, 197110 St. Petersburg,
Russia.
4 Department of Geography, University of
Bergen, Breiviksveien 40, 5045 Bergen, Norway.
*
To whom correspondence should be addressed. E-mail:
Ola.Johannessen{at}nrsc.no
