HR: 1340h
AN: A33D-0942    [Abstracts]
TI: Air-Ice Interactions Associated with a Storm Process in a 2-Dimentional Coupled Model
AU: * Cheng, B
EM: Bin.Cheng@fimr.fi
AF: Finnish Institute of Marine Research, P. O. Box 33, FIN-00931, Finland, FIN-00931 Finland
AU: Zhang, X
EM: xdz@iarc.uaf.edu
AF: International Arctic Research Center, 930 Koyukuk Dr., Fairbanks, AK 99775 United States
AU: Vihma, T
EM: timo.vihma@fmi.fi
AF: Finnish Institute of Marine Research, P. O. Box 33, FIN-00931, Finland, FIN-00931 Finland
AU: Walsh, J E
EM: jwalsh@iarc.uaf.edu
AF: International Arctic Research Center, 930 Koyukuk Dr., Fairbanks, AK 99775 United States
AB: The SHEBA deployment was carried out for an entire year from October 1997 to October 1998 and captured an outstanding warm air advection event in the middle of May 1998, when a well-developed cyclonic system moved slowly northward from the Bering Sea and the Gulf of Alaska. The Beaufort Sea was covered by the advection of warm air mass from east to west during a period from 10th through 12th May. We employed a 2-dimentional high resolution coupled atmospheric boundary layer (ABL) and sea-ice thermodynamics model to investigate the air-ice interactions during this period. The model domain was configured in the dominant direction of the prevailing winds and extended 420km downwind from the SHEBA Camp with a horizontal resolution of 5 km. The ABL had 50 levels from surface up to 3 km, while the snow and the sea-ice had 10 vertical layers, respectively, in the model. The ABL inflow boundary condition was updated every hour based on the SHEBA rawinsounding data. The ABL and the sea-ice models were spun up to a quasi-equilibrium in which the modeled surface temperature was close to the AVHRR retrieval skin temperature. During the three-day simulation, the model apparently captured the warm air advection well. The modeled spatial distribution of surface temperatures were close to the AVHRR derived values. An increase of temperature occured in the snow and upper sea-ice layer, in response to the penetration of solar radiation and invasion of warm air mass into the model domain. The former factor predominantes, while the latter amplifies the effects of the former. Heat accumulates in the snow layer, a response in part to the increasing solar radiation during this transition season. Due to the increases of air moisture carried by the advection, condensation occurs. The diurnal amplitude of the low-level air temperature and the snow/ice temperature is damped in the simulation. Parallel simulation in an uncoupled model provided insight into the feedback produced by the coupling.
DE: 3300 ATMOSPHERIC PROCESSES
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 3349 Polar meteorology
DE: 3364 Synoptic-scale meteorology
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005