HR: 0800h
AN: C11B-0442    [Abstracts]
TI: A mechanism for increasing ice mass, pushing cold ice into the upper mixed layer of the ocean
AU: * Pruis, M J
EM: matt@nwra.com
AF: NorthWest Research Associates, 14508 NE 20th Street, Bellevue, WA 98007, United States
AU: Coon, M
EM: max@nwra.com
AF: NorthWest Research Associates, 14508 NE 20th Street, Bellevue, WA 98007, United States
AB: We are exploring a process which involves the rapid growth of ice when ice blocks are submerged into the upper ocean mixed layer, such as occurs during ice deformation events that involve the ridging or rafting of blocks of sea ice. Initial observations of this mechanism were obtained during the 2007 ice camp in the Beaufort Sea. Field observations indicate that between 10 to 15 percent new ice growth by mass occurs rapidly after the ice blocks are submerged. This ice growth is focused along the long linear features and leads to a focused line source of brine being input into the uppermost layer of the ocean. This line source of brine is enhanced by brine draining out of the lead ice that is rapidly warmed by being submerged in seawater. The rates and magnitudes of these two processes, new ice growth and brine drainage from the recently submerged ice blocks, are not equal, and understanding how they vary is important. We hypothesize that these fluxes are large enough to have dynamic implications and yield an enhanced oceanic heat flux. The increase in heat flux would be due to the circulation caused by the negative surface buoyancy flux related to the injection of dense brine at the ocean surface. We will explore parameterization of these processes for ice models which explicitly model the initiation and evolution leads and ridges.
DE: 0750 Sea ice (4540)
DE: 0754 Leads (4540)
DE: 0762 Mass balance (1218, 1223)
DE: 0764 Energy balance
DE: 0798 Modeling
SC: Cryosphere [C]
MN: 2007 Fall Meeting