title: Global Warming and Northern Hemisphere Sea Ice Extent.
abstract: 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.
authors.affiliation: Department of Meteorology, University of Maryland, College Park, MD 20742, USA. Department of Environmental Sciences, Rutgers-The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ 08901-8551, USA. Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration (NOAA), Post Office Box 308, Princeton, NJ 08542, USA. Department of Atmospheric Sciences, University of Illinois, 105 South Gregory Street, Urbana, IL 61801, USA. Code 971, Oceans and Ice Branch, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Hadley Centre for Climate Prediction and Research, Meteorological Office, Bracknell, RG12 2SZ, UK. Climate Prediction Center, National Weather Service, National Centers for Environmental Prediction, NOAA, 5200 Auth Road, Room 800, Camp Springs, MD 20746, USA. Arctic and Antarctic Research Institute, 38 Bering Street, St. Petersburg 199397, Russia.
authors.initials: KY
authors.lastname: Vinnikov
authors.initials: A
authors.lastname: Robock
authors.initials: RJ
authors.lastname: Stouffer
authors.initials: JE
authors.lastname: Walsh
authors.initials: CL
authors.lastname: Parkinson
authors.initials: DJ
authors.lastname: Cavalieri
authors.initials: JF
authors.lastname: Mitchell
authors.initials: D
authors.lastname: Garrett
authors.initials: VF
authors.lastname: Zakharov