Science Bit
University of Colorado, Rutgers, NOAA
Snow cover, glaciers, and global warming
Two separate studies at the University of Colorado at Boulder
(CU) deal with possible symptoms of global warming. One team
of researchers has found that the levels of Northern
Hemisphere sea ice and snow cover in 1990 were the lowest
since satellite records began in 1973, apparently as a result
of record high surface temperatures that year. The
scientists, Mark Serreze, James Maslanik, Jeffrey Key, and
Raymond Kokaly of the CU/NOAA Cooperative Institute for
Research in Environmental Sciences (CIRES) and David Robinson
of Rutgers University, studied observations from satellites,
weather stations, ships, and the Arctic Ocean Buoy Program,
which provides weather information from buoys dropped by
plane onto drifting pieces of sea ice. The data were analyzed
by computer at CIRES. The researchers also found that 1993
was the second-lowest year on record for sea ice, and snow
cover has been below normal since the late 1980s. The
results of the NSF-supported study were published in the 15
August Geophysical Research Letters. For more
information, contact Serreze (303-492-2963 or
serreze@Kryos.colorado.edu) or Peter Caughey (303-492-4007 or
caughey@spot.colorado.edu).
Mark Meier, a glaciologist at CU's Institute of Arctic and
Alpine Research, reports that the volume of the world's
glaciers outside of Greenland and the Antarctic has
diminished markedly in the past century, and the rate of loss
appears to be accelerating. Meier says that the total mass
of small glaciers worldwide has apparently diminished by
about 11% since the late 19th Century. In some places the
change has been more dramatic; the European Alps appear to
have lost more than 50% of their ice. Annual changes in the
volume of the world's glaciers appear to be related primarily
to changes in air temperature, Meier explains; the observed
shrinkage does not appear to be related to any global change
in precipitation. An estimate of long-term temperature
trends from glacier volume change indicates global warming of
a little over half a degree Celsius. Meier can be reached at
303-492-6556 or Mark.Meier@colorado.edu, or contact James
Scott (303-492-3114 or scottjr@spot.colorado.edu).
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Edited by Carol Rasmussen,
carolr@ucar.edu
Prepared for the Web by Jacque Marshall
Last revised: Tue Apr 4 09:06:54 MDT 2000