基于等时层和冰组构联合约束的三维冰盖模式研究

The rising of sea level caused by climate warming is the global focus of attention. The melt of polar ice sheet is the main reason of sea level rising. So it has important scientific significance to understand the behavior and the evolving trend of ice sheet. Ice sheet modeling is the most efficient tools for reconstructing and predicting the mechanism and evolution of ice sheet, and become the frontier and hot research field. This application aimed at the deficiency of isochrone constraint model used in the complex environment of ice sheet, present identifying the fabric and ice flow based on polarimetric radar, which solve the uncertainty of parameters on the fabric and ice flow in isochrone constraint model, and achieve the joint constraint of isochrone and fabric, and then form a best solution for modeling complex sub-ice environment. It is important for improving the predicting ability of ice sheet modeling. The main research procedure covers: 1. the ice flow recognition based on polarimetric radar data. 2. extraction technology of typical parameters in polarimetric radar data. 3. using full Stokes anisotropic model with fabric constraint and obtaining the ice flow model for the following model. 4 the combined constraint of fabric and isochrone for modeling and get the age curve matching with the radar isochrone. 5. based on modeling comparison, applying the new model to complex sites, as Dome A.

气候变暖导致的海平面上升是全球关注的焦点问题。极地冰盖融化是海平面上升的主要原因，因此理解和把握冰盖的行为和演化趋势具有重要的科学意义。冰盖模式是重建和预测冰盖流动机制和演化规律最有效的技术手段，成为国际冰盖研究的前沿热点领域。本申请针对复杂冰下环境模拟时等时层约束模式的不足，提出利用极化雷达识别组构和冰流特征，解决等时层约束模式中冰流以及组构各向异性模式中组构不确定性问题，实现等时层和组构联合约束，形成面向复杂冰下环境模拟的最佳解决方案，对于提高冰盖模式预测能力具有重要意义。主要研究内容包括：1.极化雷达冰流识别技术研究。2.极化雷达特征参数提取技术研究，为后续模式提供约束参数。3.完全Stokes各向异性冰盖模式研究，使用组构等约束，为后续模式提供冰流场模型。4. 等时层和组构联合约束冰盖模式研究，获得与等时层匹配的冰龄曲线。5.在模式对比基础上，将研究成果应用于Dome A等复杂区域

冰盖模式是重建和预测冰盖流动和演化过程最有效的技术手段，成为国际冰盖研究的前沿热点领域。然而基于Glen法则的各向同性冰盖模式存在明显的局限性，难以适应复杂冰盖模拟需求，迫切需要考虑组构各向异性等关键影响因素；但如何获取和充分利用冰盖内部组构信息一直国际冰盖研究的前沿重难点研究方向。本课题从各向异性冰盖电磁传播理论分析入手，研发一种利用全极化雷达探测数据提取和识别组构和冰流特征的方法技术并实现冰盖组构成像。然后改进现有各向异性冰盖模式，充分利用全极化雷达提取的组构和等时层信息，实现面向复杂冰盖模拟需求的联合约束冰盖模式，并将相关研究成果应用于地球、火星冰盖研究以及月球探测，推动组构和冰盖演化机制研究的继续深化。组构成像结果揭示冰盖内存在软冰和硬冰交替出现的现象，证明与冰期间冰期气候变迁相关的灰尘微粒含量变化相关，在此基础上构建出新的冰盖内组构、应力场的分布及其演化模型。