HR: 13:45h
AN: C53A-01 INVITED     [Abstracts]
TI: Changes in Cloud Cover over the Arctic Seas from 1980-2002.
AU: * Schweiger, A J
EM: axel@apl.washington.edu
AF: University of Washington/Polar Science Center, 1013 NE 40th Steet, Seattle, Wa 98105 United States
AB: Winter and spring changes in cloudiness are compared over the arctic seas from the TOVS (TIROS Operational Vertical Sounder) Polar Pathinder retrievals and two separate datasets derived from the Advanced Very High Resolution Radiometer (AVHRR). All satellite products exhibit significant decreases in cloud fraction over the arctic seas during winter (December, January, February) on the order of 5%/decade. An equally striking increase in spring (March, April, May) cloudiness is evident from the TOVS Pathfinder (TPP) and the extended AVHRR Polar Pathfinder (APP-X) projects . Regionally these positive trends can be as large as 15%/decade. Surface observations from the Russian drifting meteorological stations are consistent with satellite- observed changes during the 1980s. Negative trends in spring cloud cloudiness reported by Comiso [2003] are in conflict with these findings. Spring changes in cloudiness are associated with changes in the atmospheric circulation. Changes in cloudiness have a direct impact on the radiation budget at the Arctic surface. Potenital links to the freshwater budget will be discussed.
DE: 4215 Climate and interannual variability (3309)
DE: 4540 Ice mechanics and air/sea/ice exchange processes
DE: 0320 Cloud physics and chemistry
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting