基于特征跟踪方法的Amery冰架上游流速估算

冰川流速分析对于研究南极冰盖物质平衡、海平面上升和全球气候变化具有重要意义。以ALOS/PALSAR影像为数据源,采用SAR特征跟踪方法,结合DEM数据估算Amery冰架上游冰川流速。结果表明,Amery冰架上游主流线流速为540—720 m·a-1,冰川流速随海拔的降低逐渐减小。受基岩和两侧山体的影响,主流线流速大,越靠近两侧山体流速越小。这个结果与NASA 2000年利用SAR重复轨道干涉测量方法测定的流速接近。基于裸露岩石作为特征点的分析表明,该方法误差较小,获取的冰川流速比较可靠。

Upstream Velocity of the Amery Ice Shelf Derived from Satellite Radar Feature Tracking

The flow rates of glaciers hold special significance in the analysis of the mass balance of the Antarctic ice sheet and its effect on sea-level rise and global climate change. In this study, ALOS/PALSAR imagery was combined with a digital elevation model, and the synthetic aperture radar intensity feature tracking method was used to obtain the upstream glacier velocity of the Amery Ice Shelf. The results showed that the flow rate of the main streamline ranged from 540 to 720 m·a^-1 in the upstream region of the Amery Ice Shelf, and gradually decreased with decreasing elevation. Under the influence of bedrock and highlands on the two sides of the shelf, the flow rate of the main streamline was negatively correlated to the distance from the surrounding highlands. This result is in accord with the flow rate that was measured by NASA in 2000 using the radar repeat track interferometry method. Our analysis using bare rocks as reference points indicates that the associated error is relatively small and the ice flow rate obtained by this approach is reliable.