HR: 0800h
AN: C41B-0203    [Abstracts]
TI: The role of melt onset timing in the recent extreme Arctic summer ice extent minima
AU: * Meier, W N
EM: walt@nsidc.org
AF: National Snow and Ice Data Center University of Colorado, UCB 449, Boulder, CO 80309 United States
AU: Stroeve, J
EM: stroeve@kryos.colorado.edu
AF: National Snow and Ice Data Center University of Colorado, UCB 449, Boulder, CO 80309 United States
AB: The recent reduction in summer ice cover in recent years has been one of the starkest indications of change in the Arctic. The September 2002 minimum extent was the lowest since the beginning of the satellite record in 1972. September 2003 was the second lowest on record and nearly as low as 2002. 2004 marks an unprecedented third year in a row of anomalously low ice extents. This marks a striking change from previous extreme low years, which have typically been followed by a rebound to higher ice extents the next year. Previous studies have indicated that a positive phase in the previous winter's Arctic Oscillation (AO) can lead to a larger export of thicker multiyear ice out of the Arctic through the Fram Strait. This results in a thinner average ice cover that is preconditioned for more extensive melt the following summer. However, in 2002-2004 the winter AO has been negative. Another possible factor leading to the September minimum extent is the length of the melt season. Warmer spring and summer temperatures that can result in earlier melt have been noted in many regions of anomalously low summer extents. Here, we investigate links between the timing of the melt onset, based on passive microwave data, with the following September extent as a possible factor in the extreme minima of the past three years.
DE: 9315 Arctic region
DE: 6969 Remote sensing
DE: 4207 Arctic and Antarctic oceanography
DE: 4275 Remote sensing and electromagnetic processes (0689)
DE: 4540 Ice mechanics and air/sea/ice exchange processes
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting