Gain Immediate access to our Essays
FREE access exchanged for your work, or pay £9.99
... They suggest an average thickness of 3 to 3.5 meters and little change in time. Declassified submarine sonar observations of the ice draft taken between 1958 and 1976 corroborate this information. However, the unclassified cruises of the SCICEX program, 1993-199t show a significant, locally variable, thinning of the ice by 1-2 meters (Rothrock et al., 2000). It is likely that most of this thinning occurred in the last two decades of the century. These findings are supported by satellite-based passive microwave observations, which are capable of distinguishing first-year from multi-year ice, that the area fraction covered by my multi-year ice has shrunk by 14% between 1978 and 1998 (Johannessen et al., 1999). The average thinning of the ice appears to be the result of both the diminished fraction of multi-year ice and the relative thinning of all ice categories. Both the shrinking and thinning of the arctic sea ice cover appear to ...