Validation of the GRACE-derived gravity variations in the Antarctic region

验证 GRACE 得出的南极地区重力变化

基本信息

批准号：
16310015
负责人：
SHIBUYA Kazou
金额：
$ 10.11万
依托单位：
National Institute of Polar Research
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16310015/
关键词：
GRACE satellite validation Antarctica VLBI GPS precise gravimetry OBP seepage meter

项目摘要

Our research aims at detecting gravity variations related with atmosphere-ocean-ice sheet change in the Antarctic region, and interpreting GRACE-satellite derived gravity variations together with the ground-truth geodetic validation data. From the analysis of 1999-2003 VLBI epoch campaign data, crustal uplift rate at Syowa Station was estimated as 4.6±2.2 mm/yr (Fukuzaki et al., 2005). This value is close to the DORIS result of 3.6±0.2 mm/yr by Amalvict et al. (2007), but is somewhat larger than the GPS result (1.4±0.2 mm/yr ; Ohzono et al., 2006) observed in the outcrop area of Lutzow-Holm Bay. The repeated absolute gravity measurements at Syowa Station revealed gravity decrease of-0.27 μGal/yr (Fukuda et al., 2006), and these space geodesy and precise gravimetry data are key factors to constrain glacial isostatic adjustment model as indicated by Makinen et al. (2007). Konishi et al. (2007) treated 17 years' onboard Shirase ship-gravimeter data with a unified drift correction model, and the obtained gravity anomalies will be used to improve static regional gravity field by joint Japan-Germany airborne geophysics surveys. This in turn will give us more precise and detailed dynamic gravity variations. As for new devices, OBPs deployed at (66°51'S, 37°49'E, 4600m sea depth) recorded sea-level change associated with the tsunami from the 2004 December 26 Sumatra Earthquake, and its loading effect to the SG and the STS was estimated by Nawa et al. (2007). It was shown that the residual OBP sea-level amplitudes after subtraction of tidal constituents have variations which are in phase with the GRACE monthly gravity variations. The seepage meter installed at the sea bottom of 800m in Lutzow-Holm Bay by JARE-46 recorded the value of 10^<-8> to 10^<-6> m/s, indicating the value of similar magnitude obtained in mid-latitudes. These two devices showed effectiveness of applicability in understanding water mass variations in the Antarctic region.

我们的研究旨在检测与南极地区大气-海洋-冰盖变化相关的重力变化，并根据对 1999-2003 年 VLBI 历元活动数据的分析来解释 GRACE 卫星得出的重力变化以及地面实况大地测量验证数据。，昭和站的地壳抬升率估计为 4.6±2.2 毫米/年（Fukuzaki 等，2005）。与 Amalvict 等人 (2007) 的 DORIS 结果 3.6±0.2 mm/yr 接近，但略大于在 2006 年露头区域观测到的 GPS 结果 (1.4±0.2 mm/yr)。 Lutzow-Holm 湾。昭和站的重复绝对重力测量显示重力减少了约 0.27 μGal/yr（Fukuda 等人， 2006），并且这些空间大地测量和精确重力测量数据是约束冰川均衡调整模型的关键因素，正如 Konishi 等人（2007）用 17 年的船载重力仪数据处理的那样。统一的漂移修正模型，获得的重力异常将用于日德联合机载地球物理勘测改善静态区域重力场。将为我们提供更精确和详细的动态重力变化。至于新设备，部署在（南纬 66°51'，东经 37°49'，海深 4600m）的 OBP 记录了与 2004 年 12 月 26 日苏门答腊地震海啸相关的海平面变化。 Nawa 等人 (2007) 估计了其对 SG 和 STS 的负载影响。减去潮汐成分后的变化与GRACE月重力变化同相。JARE-46安装在Lutzow-Holm湾800m海底的渗流计记录了10^<-8>至10^的值。 <-6> m/s，表明在中纬度地区获得的类似震级值。这两个装置在了解南极地区水体变化方面显示出适用性。