HR: 0800h
AN: C11B-0451    [Abstracts]
TI: A preliminary study of AMSR-E sea ice temperature products for snow-ice flooding detection
AU: * Xie, H
EM: hongjie.xie@utsa.edu
AF: Laboratory for Remote Sensing and Geoinformatics, UTSA, One UTSA Cycle, San Antonio, TX 78249, United States
AU: Lewis, M
EM: michael.lewis@swri.org
AF: Laboratory for Remote Sensing and Geoinformatics, UTSA, One UTSA Cycle, San Antonio, TX 78249, United States
AU: Ackley, S F
EM: stephen.ackley@utsa.edu
AF: Laboratory for Remote Sensing and Geoinformatics, UTSA, One UTSA Cycle, San Antonio, TX 78249, United States
AB: In this study, we examined AMSR-E Sea Ice Temperature product as compared with ice mass balance buoy data from the Southern GLOBEC (Global Ocean Ecosystems Dynamics) project in the Marguerite Bay area on the west side of the Antarctic peninsula (Perovich et al. 2004). This area was noted by Perovich et al. (2004) to have extensive surface flooding of ice floes during the 2001 and 2002 austral spring seasons. Co-located and concurrent AMSR-E Daily Averaged Brightness Temperatures and Sea Ice Temperature (L3, 25 km) data were obtained from a pixel or pixels corresponding to the daily position of the buoy. Several results have been found. (1) the AMSR-E product is generally significantly colder than the actual snow-ice temperature as measured by the buoys, which brings into question its value as a representative of snow-ice temperature, as we have documented previously (Lewis and Xie, 2006; Lewis et al., 2006). (2) when the buoy interface temperature rises to ~~271 K, indicative of surface flooding (Sept. 16), the AMSR-E temperature, instead of a corresponding rise, shows a drop almost instantaneously (within the daily frequency of measurement) of 6?0 K below the buoy interface temperature, although nearly 7 days prior to the buoy interface temperature~{!/~}s indication of surface flooding. As another flooding event (Oct. 29) is indicated by the buoy temperature rise at the end of the record, the AMSR-E again undergoes a sharp decline of 6?0 K, this time nearly at the same time as the buoy temperature indication of flooding. We explain that the good match of the later event, Oct. 29, may be representative of a regional large flooding event, while the Sept. 9 event was actually the first representative flooding event for the region. But locally, at the buoy position, this event did not happen until Sept. 16 as snow depth continued to increase. This result suggests that snow-ice interface flooding events may be detected by rapid brightness temperature decreases from AMSR-E, in contrast to actual interface temperature increases resulting from the sea water intrusion. This analysis projects a great potential of using the AMSR-E temperature to detect flooding events of regional scale. More previous in-situ measurements and their relative AMSR-E data will be analyzed to further test this hypothesis. ht
UR: http://www.utsa.edu/LRSG/
DE: 0736 Snow (1827, 1863)
DE: 0750 Sea ice (4540)
DE: 0758 Remote sensing
DE: 0794 Instruments and techniques
SC: Cryosphere [C]
MN: 2007 Fall Meeting