HR: 09:00h
AN: C31B-05 INVITED     [Abstracts]
TI: The Properties and Ice Production of the Ross Sea Polynya during 1992-2002, and its Interaction with Large Icebergs in 2000-2002
AU: * Martin, S
EM: seelye@ocean.washington.edu
AF: University of Washington, School of Oceanography, Box 357940, Seattle, WA 98195-7940 United States
AU: Drucker, R
EM: robert@ocean.washington.edu
AF: University of Washington, School of Oceanography, Box 357940, Seattle, WA 98195-7940 United States
AU: Kwok, R
EM: ron@rgps1.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Holt, B
EM: ben@pacific.jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AB: The Ross Shelf polynya (RSP) occurs in the western Ross Sea adjacent to the Ross Ice Shelf. It is the largest Antarctic winter polynya, and compared to the other western Ross Sea polynya at Terra Nova Bay (TNB), is relatively unstudied. The importance of both polynyas is that they generate the High Salinity Shelf Water (HSSW), which interacts with the ice shelf to form Antarctic deep and bottom water. For 1992-2002, we use meteorological, MODIS, SSM/I, SAR and for 2002, AMSR data to determine the properties of the RSP and compare them with the TNB. The polynya areas are calculated using a 0-10 cm SSM/I 37 GHz thin ice algorithm with a 25-km resolution; the heat loss is calculated from the ice thickness and meteorological data. The comparison shows that the mean area and ice production of the RSP is six times that of the TNB. Further, for the RSP, 1992-2002 study period divides into three parts, 1992-1999, when no major icebergs were present, 2000 and 2002, when large icebergs of length 100-200 km and width 20-40 km calved and drifted across the RSP, and 2001, when berg B-15A was grounded at its south end on Ross Island. In 2001, the long axis of B-15A was at right angles to the shelf, in 2000 and 2002, the long axes of the bergs were generally parallel to the shelf. For 2000 and 2002, the bergs inhibited the RSP, while new polynyas formed downwind of the bergs. During 2000, the presence of these multiple new polynyas enhanced the ice production by 50 percent. Because similar calving occurred in 1987 and sometime between 1948-1955, the impact of large icebergs on the Ross Sea polynya productivity may need to be considered in estimates of the bottom water production.
UR: http://polar.ocean.washington.edu/ROSS/
DE: 0732 Icebergs
DE: 0750 Sea ice (4540)
DE: 0758 Remote sensing
DE: 4207 Arctic and Antarctic oceanography (9310, 9315)
DE: 4540 Ice mechanics and air/sea/ice exchange processes (0700, 0750, 0752, 0754)
SC: Cryosphere [C]
MN: Fall Meeting 2005