GOCE, Satellite Gravimetry and Antarctic Mass Transports
GOCE, Satellite Gravimetry and Antarctic Mass Transports
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DOI：
10.1007/s10712-011-9115-5
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发表时间：
2011-03
影响因子：
4.6
通讯作者：
R. Rummel;M. Horwath;W. Yi;A. Albertella;W. Bosch;R. Haagmans
中科院分区：
文献类型：
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作者：
R. Rummel;M. Horwath;W. Yi;A. Albertella;W. Bosch;R. Haagmans
2009年，欧洲空间局卫星使命GOCE（重力场和稳态海洋环流探测器）发射升空。其目标是精确和详细地确定地球的重力场和大地水准面。它的核心仪器是三轴重力梯度仪，在仪器坐标系内高精度地测量重力梯度分量Vxx、Vyy、Vz和Vz（重力位V的二阶导数），低精度地测量Vxy、Vyz。利用GPS（Global Positioning System）卫星的测量数据，从轨道上恢复了长波重力场。该使命的特点是精确的星星跟踪、太阳同步和极低（260公里）轨道、通过磁力扭矩进行角度控制以及极其坚固和热稳定的仪器环境。GOCE是对GRACE（重力恢复和气候实验）的补充，GRACE是2002年发射的另一个卫星重力使命。GRACE的目的是测量时间重力变化，尽管空间分辨率有限，GOCE的目标是最大的空间分辨率，在大空间尺度的精度为代价。因此，GOCE将不提供时间变化，但适合于恢复静止场的精细尺度。GRACE在提供南极冰盖大规模质量变化的时间序列方面非常成功。目前，各自的GRACE分析的重点是区域细化和时间趋势的变化。挑战之一是将冰量变化与冰川均衡调整分开。从几个月的GOCE数据中，已经可以恢复详细的重力梯度。这里介绍的是南极洲的情况。作为一种应用，GOCE重力梯度是对南极洲稀疏重力数据的重要补充。它们将有助于地壳和岩石圈场的研究。第二个应用领域是海洋环流。重力场模型GOCO01S的大地水准面使我们现在能够生成南极绕极流区域的平均动态海洋地形和地转流速的相当详细的地图。
In 2009 the European Space Agency satellite mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched. Its objectives are the precise and detailed determination of the Earth’s gravity field and geoid. Its core instrument, a three axis gravitational gradiometer, measures the gravity gradient componentsVxx,Vyy,VzzandVxz(second-order derivatives of the gravity potentialV) with high precision andVxy,Vyzwith low precision, all in the instrument reference frame. The long wavelength gravity field is recovered from the orbit, measured by GPS (Global Positioning System). Characteristic elements of the mission are precise star tracking, a Sun-synchronous and very low (260 km) orbit, angular control by magnetic torquing and an extremely stiff and thermally stable instrument environment. GOCE is complementary to GRACE (Gravity Recovery and Climate Experiment), another satellite gravity mission, launched in 2002. While GRACE is designed to measure temporal gravity variations, albeit with limited spatial resolution, GOCE is aiming at maximum spatial resolution, at the expense of accuracy at large spatial scales. Thus, GOCE will not provide temporal variations but is tailored to the recovery of the fine scales of the stationary field. GRACE is very successful in delivering time series of large-scale mass changes of the Antarctic ice sheet, among other things. Currently, emphasis of respective GRACE analyses is on regional refinement and on changes of temporal trends. One of the challenges is the separation of ice mass changes from glacial isostatic adjustment. Already from a few months of GOCE data, detailed gravity gradients can be recovered. They are presented here for the area of Antarctica. As one application, GOCE gravity gradients are an important addition to the sparse gravity data of Antarctica. They will help studies of the crustal and lithospheric field. A second area of application is ocean circulation. The geoid surface from the gravity field model GOCO01S allows us now to generate rather detailed maps of the mean dynamic ocean topography and of geostrophic flow velocities in the region of the Antarctic Circumpolar Current.