Collaborative Research: Calculation of Antarctic Gravity Field from GRACE satellite data and comparison with independent measurements

合作研究：利用 GRACE 卫星数据计算南极重力场并与独立测量结果进行比较

• 批准号: 0338278
• 负责人: Robin Bell
• 金额: --
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0338278&HistoricalAwards=false
• 关键词: Collaborative; Research; Calculation; Antarctic; Gravity

This is a proposal to process the GRACE satellite range, range-rate, and range-acceleration data with a goal to obtain a map of the geoid over the Antarctic with spatial resolution between 35 and 100 km. The free-air gravity derived from this geoid should fundamentally change our view on geological structure and history of the Antarctic continent in much the same way that the GEOSAT mission impacted our understanding of plate tectonics in the world's oceans. Due to resource limitations, however, the GRACE project team will not use the range and its derivatives to generate high spatial resolution estimates of the gravity field along the satellite ground track. The new geoid and derived free-air gravity field will require development of an algorithm to process the range, range-rate and range acceleration data and convert them to a self-consistent geoid. The GRACE-derived gravity field will be compared with marine, airborne gravity and land-based surveys as well as with major geological features of the Antarctic continent to assess wavelength resolution. This comparison will require the integration of the airborne and marine data sets and determination of the subglacial topography for some of the airborne surveys. Once the new geoid and derived fee-air gravity have been generated, the continent-wide subglacial topography could be estimated via an optimal co-kriging interpolation of the available bedrock measurements and the geoid, joint with the statistical relationships describing the spatial variation of topography, and the spatial correlation of the geoid and topography. The subglacial topography will be also determined using an alternative approach, the Parker inversion method. These products will be made available to the ice sheet modeling community. The new continent-wide subglacial topography will be used in combination with altimetric ice surface elevations to calculate a new estimate of Antarctic ice sheet volume, which can be used to calibrate the eustatic sea-level curve from oxygen isotope data for the present and maximum possible variations of the global sea level curve. The new subglacial topography estimates will also be used to interpret geologic structures of the Antarctic and the processes responsible for their formation. This research will have several areas of broader impact and intellectual merit: (a) the map of subglacial topography, together with an improved estimate of the Antarctic ice volume, will be an important contribution to the science goals of the Antarctic Climate Evolution initiative (ACE). Modeling the nucleation of the East Antarctic ice sheet relies on high-quality subglacial topography models, as well as modeling the drainage of the entire ice sheet. (b) The proposed GRACE-derived gravity approach, if proven to be successful, can be applied to the Arctic region and indeed to the entire world. While the Arctic gravity field is of high quality south of 82 N (ERS-1 orbit coverage), a large polar gap remains. Mapping the main geological features in these hard-to-reach parts of the world from satellite measurements would be a significant step forward in understanding the plate tectonic features of the Artic and Antarctic and should extend significantly recent marine geological and tectonic studies of the region.

这是处理GRACE卫星范围，范围率和加速数据的建议，其目标是在南极范围内以35至100 km的空间分辨率获得地图图。从该大地衍生出的自由气重力应从根本上改变我们对南极大陆的地质结构和历史的看法，就像Geosat任务影响了我们对世界海洋中板块构造的理解一样。但是，由于资源限制，Grace项目团队不会使用范围及其衍生工具来对沿卫星地面轨道的重力场进行高空间分辨率估算。新的Geoid和派生的自由压力场将需要开发算法来处理范围，范围速率和范围加速度数据，并将其转换为自一致的大地型。将宽限的重力场与海洋，空中重力和陆基调查以及南极大陆的主要地质特征进行比较，以评估波长分辨率。这种比较将需要对某些空气传播调查的空降和海洋数据集的整合以及测定冰川地形的测定。一旦产生了新的Geoid和衍生的费用引力，就可以通过最佳的可用基岩测量值的最佳共同插入插值来估算大陆范围内的冰片地形，并且与统计关系的统计关系，描述了地图的空间变化，以及统计关系的统计关系，以及地图的空间互相互动，以及地理位置和座椅的空间相关性。冰川地形还将使用替代方法（Parker倒置方法）确定。这些产品将提供给冰盖建模社区。新的范围范围范围的冰川地形将与高空冰表面高程结合使用，以计算南极冰盖体积的新估计值，可用于从氧气同位素数据中校准Eustatic Sea层型曲线，以实现当前和最大的全球海平面海平面曲线变化。新的冰川地形估计值还将用于解释南极的地质结构及其造成其形成的过程。这项研究将具有更广泛的影响和智力优点的几个领域：（a）冰川地形地图以及对南极冰量的改进，将是对南极气候进化倡议（ACE）科学目标的重要贡献。建模南极冰盖的成核依赖于高质量的亚冰块地形模型，以及对整个冰盖的排水进行建模。 （b）拟议中的宽限期重力方法，如果被证明是成功的，则可以应用于北极地区，甚至可以应用于整个世界。虽然北极重力场位于82 N（ERS-1轨道覆盖范围）的高质量南部，但仍然存在较大的极性间隙。通过卫星测量来映射世界难以触及的部分的主要地质特征将是理解Artic and Attroctic的板块构造特征的重要一步，并应大大扩展该地区的海洋地质和构造研究。