HR: 08:00h
AN: C11C-01    [Abstracts]
TI: Using Synthetic Aperture Radar and Lagrangian sea ice tracking to study the seasonal evolution of pack ice thickness and other characteristics
AU: * Heinrichs, J
EM: jheinric@fhsu.edu
AF: Fort Hays State University, 211 W 21, Hays, KS 67691, United States
AU: Coveney, E
EM: ewcoveney@scatcat.fhsu.edu
AF: Fort Hays State University, 211 W 21, Hays, KS 67691, United States
AU: Lane, S T
EM: stlane@scatcat.fhsu.edu
AF: Fort Hays State University, 211 W 21, Hays, KS 67691, United States
AB: Synthetic Aperture Radars (SARs) respond to the composition and structure of sea ice - which in turn are related to ice age and, indirectly, ice thickness. Examining the evolution of Arctic pack ice characteristics is particularly challenging, since this ice is continuously moving. The traditional Eulerian approach (studying the ice in a particular location) is not effective because ice from different source regions passes through any given study area. This study employed a Lagrangian approach, in which individual parcels of ice were tracked on their journeys through the Arctic. The time series of RADARSAT backscatter from the ice parcels was extracted and then analyzed using a semi-empirical forward simulation model to isolate the factors most responsible for backscatter variability. Results indicate that the backscatter variability of pack ice parcels during the winter and spring is primarily due to incidence angle, the amount of open water within the pack, and the formation and freezing of thin ice in leads. Also revealed in the SAR data are changes in the backscatter of first-year ice as the ice thickens. Changes in the thickness of multiyear ice during winter and spring have little effect on the radar backscatter. The onset of melt in the snow cover causes a precipitous drop in backscatter, after which the amount of liquid water in the snowpack becomes a major source of backscatter variability. Ice that survived summer melt was found to have significantly altered backscatter characteristics in the following winter.
DE: 0750 Sea ice (4540)
DE: 0758 Remote sensing
DE: 0770 Properties
SC: Cryosphere [C]
MN: 2007 Fall Meeting