HR: 0800h
AN: U21C-0620    [Abstracts]
TI: High Resolution Recovery of Amazon Basin Water Storage Change Using Line-Of-Sight (LOS) Gravity Difference Data from GRACE
AU: * Chen, Y
EM: chen.862@osu.edu
AF: the ohio state university, 275 Mendenhall Lab., 125 S. Oval Mall, columbus, oh 43210,
AU: Alsdorf, D
EM: alsdorf.1@osu.edu
AF: the ohio state university, 275 Mendenhall Lab., 125 S. Oval Mall, columbus, oh 43210,
AU: Beighley, R
EM: beighley@mail.sdsu.edu
AF: San Diego State University, 5500 Campanile Drive, San Diego, CA 92182,
AU: Shum, C
EM: ckshum@osu.edu
AF: the ohio state university, 275 Mendenhall Lab., 125 S. Oval Mall, columbus, oh 43210,
AU: Schaffrin, B
EM: schaffrin.1@osu.edu
AF: the ohio state university, 275 Mendenhall Lab., 125 S. Oval Mall, columbus, oh 43210,
AB: GRACE Level 1B data have been analyzed and processed to recover continental water storage in a regional solution, by first estimating in situ Line-Of-Sight (LOS) gravity differences simultaneously with the relative position and velocity vectors of the twin GRACE satellites. This new approach has been validated using a simulation study over the Amazon basin (with three different regularization methods to stabilize the downward continuation solutions) and it is demonstrated that the method achieves an improved spatial resolution as compared to some of the other GRACE processing techniques, including global spherical harmonic solutions, and regional solution using in situ geopotential differences. When compared with a fine-scale (20 km full-wavelength) hydrologic model of the Amazon basin, which accounts for the modeling of surface, subsurface, channel and floodplain stores and fluxes, the GRACE solutions show no discernible time lags with respect to the hydrologic model, resolving the controversy of the allegedly observed 1–2 month lags between GRACE and a number of global hydrologic models. The comparison also enables quantification of the respective contributors of the Amazon Basin water flow dynamics.
DE: 1217 Time variable gravity (7223, 7230)
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
DE: 1846 Model calibration (3333)
DE: 1847 Modeling
DE: 1855 Remote sensing (1640)
SC: Union [U]
MN: 2007 Fall Meeting