HR: 10:35h
AN: C12B-02 INVITED     [Abstracts]
TI: Ice shelf tides: Modeling, detection and removal
AU: * Padman, L
EM: padman@esr.org
AF: Earth & Space Research, 3350 SW Cascade Ave., Corvallis, OR 97333 United States
AU: Fricker, H A
EM: hafricker@ucsd.edu
AF: Institute of Geophysics and Planetary Physics, Scripps Institution fo Oceanography, University of California, Sab Diego, La Jolla, CA 92093 United States
AU: King, M A
C12B-02 AF: School of Civil Engineering and Geoscience, Cassie Building, University of Newcastle, Newcastle upon Tyne, NE1 7RU United Kingdom
AB: The ocean tide is the dominant source of vertical motion for the floating ice shelves surrounding Antarctica, the most important cause of sub-ice-shelf ocean mixing and basal melt, and a significant contributor to the gravity signal detected by the GRACE satellite mission. For applications such as long-term trend detection from satellite altimetry and gravity, accurate removal of the tide is an essential processing step. However, tide model accuracy for Antarctic regions is lower than for mid-latitude oceans, for two reasons: (1) basic model inputs such as coastline/grounding-line locations, water depth, and sub-ice-shelf water column thickness are poorly known; and (2) there is no high quality data set of sea surface (and ice shelf) elevation comparable to the TOPEX/Poseidon radar altimetry available for the ice-free ocean equatorward of 66 degrees. In this talk we review recent efforts to identify the optimum tide model from presently available models, then discuss methods for further improving the accuracy of Antarctic tide models through assimilation of multiple data types including satellite altimetry from the ERS and ICESat missions and in situ data from ice shelf GPS and ocean moorings. We conclude with a discussion of progress towards prediction of tidal displacements of the ice shelf within the grounding zone (GZ), an effort which depends on improving maps of the grounding line location and GZ width and decreasing tide model grid spacing to order 1 km.
DE: 0728 Ice shelves
DE: 0798 Modeling
SC: Cryosphere [C]
MN: Fall Meeting 2005