基于卫星遥感和测高数据的南极冰盖冰流速和接地线动态变化监测

Ice flow velocity is an indispensable parameter for the calculation of ice flux. And the ice flux across the grounding line is the main output component of ice sheet mass balance. Monitoring the dynamic changes of ice velocity and grounding line is of great significance for the study of ice shelf collapse, ice flow dynamics, ice sheet mass balance, global climate and environment changes, etc. Based on time-series data, mainly composed of radar interferometry data and supplemented with altimetry data and optical images, the dynamic monitoring of ice velocity and grounding line are studied in this project. This study aims to accurately determinate the ice flow velocity and monitor the seasonal and annual changes based on differential InSAR and offset tracking. And the feature tracking and GPS are chosen as the complementary methods. Meanwhile, the grounding line and its spatio-temporal changes of ice shelves and outlet glaciers will be dedected with differential InSAR and satellite altimetry. And optical and SAR images are taken as the complementary data. Moreover, the analysis of the changes in ice velocity and grounding line and the estimate of ice mass balance will be carried out in this project, which provide important reference for the future study of ice flow dynamics, global sea level, global climate and environment changes, etc.

冰流速是计算冰通量不可缺少的参数，而流过接地线处的冰通量是陆地冰物质平衡中主要的物质支出项。监测两极冰盖冰流速及接地线变化，对于研究两极冰架崩解、冰流动力学模型、冰盖物质平衡及对全球气候和环境的影响等具有重大意义。本研究以星载雷达干涉数据为主体，辅以测高数据、光学卫星影像等多源遥感数据构成时间序列，以监测冰流速和接地线的动态变化为主线，开展冰盖动态变化监测研究。基于差分干涉测量和偏移量跟踪，辅以特征跟踪和GPS测量，高精度定量监测冰流速及其季节和年际变化；基于差分干涉测量和卫星测高数据，辅以光学和SAR影像，探测冰架和溢出冰川的接地线并监测其时空变化特征；并对冰流速和接地线的变化原因进行深入分析，对冰架、溢出冰川物质平衡状态进行评价，为后续的冰流动力学分析、全球海平面变化研究以及全球气候变化研究等提供重要参数。

冰流速是计算冰通量不可缺少的参数，而流过接地线处的冰通量是陆地冰物质平衡中主要的物质支出项。监测两极冰盖冰流速及接地线变化，对于研究两极冰架崩解、冰流动力学模型、冰盖物质平衡及对全球气候和环境的影响等具有重大意义。本项目以监测冰流速和接地线的动态变化为主线，完善现有算法，提高参数产品精度，实现了冰川动态变化的高精度定量监测，分析并总结了其动态变化的规律与原因；此外，利用多源遥感数据监测冰盖高程变化，冰架、冰川和海岸线的变化，冰面融化和冰下湖的活动情况，为后续的南极冰架动态变化监测提供数据和技术基础；最后利用冰流速和接地线结果评价东南极Amery冰架的物质平衡状态。本项目的主要研究成果包括：冰面流速的高精度测定及季节和年际变化提取；接地线探测及时空变化特征分析；冰盖表面高程及高程变化提取；南极冰架、冰川和海岸线变化监测；冰面融化对冰盖动力过程和物质平衡的影响分析；南极冰下湖活动监测及水文分析；冰架/冰川物质平衡状态的评价。