HR: 0800h
AN: U21C-0623    [Abstracts]
TI: Antarctic ice sheet mass balance estimation by combing GRACE, ICESat and in situ data
AU: * Yamamoto, K
EM: yamamoto@kugi.kyoto-u.ac.jp
AF: Geophysics, Science, Kyoto University, Kitashirakawa Oiwake-Cho, Kyoto, 6068502, Japan
AU: Fukuda, Y
EM: fukuda@kugi.kyoto-u.ac.jp
AF: Geophysics, Science, Kyoto University, Kitashirakawa Oiwake-Cho, Kyoto, 6068502, Japan
AU: Doi, K
EM: doi@nipr.ac.jp
AF: National Institute of Polar Research, 1-9-10, Kaga, Itabashi-ku, Tokyo, 1738515, Japan
AB: An accurate knowledge of Antarctic ice sheet mass balance is one of the important problems for the studies of global sea level change and climate change. One of the advantages to use GRACE gravity field solutions for the study of Antarctic ice sheet mass balance is that GRACE can reveal total mass balance over Antarctica, which is closely related to the global sea level changes, e.g. Velicogna and Wahr (2006). Because of the expanding of the time span of the released data sets and the improvement of the data quality, we can obtain more reliable interannual mass trend with GRACE data. However, the estimated total Antarctic ice sheet mass balance still has large uncertainty because of the large difference of the PGR estimation with several ice models and the difference of GRACE solutions between the 3 data centers. To decrease such uncertainty and to obtain more reliable ice sheet mass trend, we have to validate the estimated values of GRACE mass trends and the PGR predictions. It is important to investigate the smaller regional scale mass trends under considering the spatial distribution of the Antarctic mass trend because of the different geographical and geological feature by each region. Thus, in this study, we firstly investigated three prominent mass trend areas in Antarctica. We discussed the main sources of the each mass trend and estimated ice sheet mass components by combing the results of in situ and other satellite observed data, e.g. snow-stakes data, continuous GPS results and ICESat data. We also investigated other small mass trend areas. Because of the large area, they give relatively large contribution to the total Antarctic mass trend even if the trend is small. Thus, considering the contribution of the mass trends of each small region to the total Antarctic ice sheet mass variation, we finally discussed how much the total Antarctic ice sheet mass estimation is improved and the uncertainty is decrease by investigating the small scale mass variation in detail.
DE: 0762 Mass balance (1218, 1223)
DE: 1217 Time variable gravity (7223, 7230)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1621 Cryospheric change (0776)
SC: Union [U]
MN: 2007 Fall Meeting