Konstantin Y. Vinnikov,
1*
Alan Robock,
2
Ronald J. Stouffer,
3
John E. Walsh,
4
Claire L. Parkinson,
5
Donald J. Cavalieri,
5
John F. B. Mitchell,
6
Donald Garrett,
7
Victor F. Zakharov
8
Surface and satellite-based observations show a decrease
in Northern Hemisphere sea ice extent during the past 46 years. A comparison of these trends to control and transient integrations (forced by observed greenhouse gases and tropospheric sulfate aerosols)
from the Geophysical Fluid Dynamics Laboratory and Hadley Centre
climate models reveals that the observed decrease in Northern Hemisphere sea ice extent agrees with the transient simulations, and
both trends are much larger than would be expected from natural climate
variations. From long-term control runs of climate models, it was found
that the probability of the observed trends resulting from natural
climate variability, assuming that the models' natural variability is
similar to that found in nature, is less than 2 percent for the
1978-98 sea ice trends and less than 0.1 percent for the 1953-98 sea
ice trends. Both models used here project continued decreases in sea
ice thickness and extent throughout the next century.
1 Department of Meteorology, University of
Maryland, College Park, MD 20742, USA.
2 Department
of Environmental Sciences, Rutgers--The State University of New Jersey,
14 College Farm Road, New Brunswick, NJ 08901-8551, USA.
3 Geophysical Fluid Dynamics Laboratory, National
Oceanic and Atmospheric Administration (NOAA), Post Office Box 308, Princeton, NJ 08542, USA.
4 Department of
Atmospheric Sciences, University of Illinois, 105 South Gregory Street,
Urbana, IL 61801, USA.
5 Code 971, Oceans and Ice
Branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
6 Hadley Centre for Climate Prediction and Research,
Meteorological Office, Bracknell, RG12 2SZ, UK.
7 Climate Prediction Center, National Weather
Service, National Centers for Environmental Prediction, NOAA, 5200 Auth Road, Room 800, Camp Springs, MD 20746, USA.
8 Arctic and Antarctic Research Institute, 38 Bering
Street, St. Petersburg 199397, Russia.
*
To whom correspondence should be addressed. E-mail:
kostya{at}atmos.umd.edu
