Global modelling of the lithosphere and mantle and explaning geoid signal by merging of tomography derived mantle flow models with full thermal convection models including lateral viscosity variations

S重力场和大地水准面对地球内部的密度结构和动力学过程非常敏感，这些结构和动力学过程强烈地影响着地球表面。全球完整和均匀的重力和大地水准面模型及其时间变化是由新的CHAMP和GRACE卫星以前所未有的精度提供的。这些数据为更好地了解全球地球结构和动力学提供了独特的机会，新的重力数据将与其他数据(地震P、S速度、地表地形、全球定位系统得出的表面速度、热流)一起用于研究全球地球结构，定量描述潜在的动力和热对流过程，并模拟地球S表面的相关响应。这些目标将通过建立一个描述地幔和地壳的主要性质和动力学的全球三维地球模型来实现。由于全球过程强烈影响区域构造制度，还将特别注意区域尺度上的时间相关过程的跨尺度模拟，例如碰撞带和相关的时间相关重力信号。因此，该项目将试图从地球动力学过程的角度解释静态重力场的主要长波贡献、弱的高阶区域变化和非常弱的时间变化。

The Earth¿s gravity field and geoid are very sensitive to the density structure and dynamic processes within the Earth that strongly influence its surface. Globally complete and homogenous gravity and geoid models as well as their temporal variations are, being provided by the new satellite missions CHAMP and GRACE with unprecedented accuracy. These data offer a unique opportunity to better understand global Earth structure and dynamics, The new gravity data will be used with other data (seismic P-, S-velocities, surface topography, GPS-derived surface velocities, heat flow) to investigate global Earth structure, to quantitatively describe the underlying dynamic and thermal convection processes, and to model the associated response of the Earth¿s surface. These goals will be achieved by the construction of a global 3D model of the Earth that describes the main properties and dynamics of the mantle and crust. Because global processes strongly influence regional tectonic regimes, special attention will also be placed on cross-scale modelling of time-dependent processes on regional scales such as collision zones and the associated timedependent gravity signals. Thus this project will attempt to explain both the dominating long wavelength contributions of the static gravity field, the weak higher degree regional variations and the very weak temporal variations in terms of geodynamic processes.