HR: 1340h
AN: C33A-0336    [Abstracts]
TI: Data Assimilation Methods for Estimating the Mass Balance of Large Ice Sheets.
AU: Arthern, R J
EM: rart@pcmail.nerc-bas.ac.uk
AF: Physical Science Division British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AU: * Hindmarsh, R C
EM: rcah@bas.ac.uk
AF: Physical Science Division British Antarctic Survey, High Cross Madingley Road, Cambridge, CB3 0ET United Kingdom
AB: We describe progress towards applying data assimilation methods for estimating the mass balance of the large ice-sheets covering Greenland and Antarctica. Data assimilation has the advantage over conventional methods of bringing all relevant measurements to bear on the estimation of changes in the mass of ice sheets. Observations of elevation change, ice flow velocity, ice thickness, and snow accumulation can all be incorporated. An optimal estimation algorithm has been developed, and used successfully to estimate mass balance of the small ice cap of Berkner Island. This paper discusses the additional challenges posed by extending the approach to the much larger scale of Antarctica. To perform successful inversions on this scale, methods for reduced rank approximation of the covariance of the state vector of an isothermal ice flow model have been developed. Numerical simulations are used to identify the data sources and sampling necessary for succesful inversion using this technique.
DE: 9310 Antarctica
DE: 1827 Glaciology (1863)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting