Radar characterization of the basal interface across the grounding zone of an ice-rise promontory in East Antarctica
Radar characterization of the basal interface across the grounding zone of an ice-rise promontory in East Antarctica
复制标题
南极洲东部冰升海角接地区基底界面的雷达特征
DOI：
10.3189/2012aog60a106
复制
发表时间：
2012
影响因子：
2.9
通讯作者：
H. Conway
中科院分区：
文献类型：
--
作者：
K. Matsuoka;F. Pattyn;D. Callens;H. Conway
摘要对东南极洲德龙宁毛德地一个冰隆岬和邻近的罗伊博杜安冰架上一条42 km长的剖面上基底界面沿着返回的雷达功率进行了分析，以推断基底反射率的空间变化，从而推断基底环境。从基底反射功率中提取基底反射率需要一个冰内衰减模型。我们用两种方法估计衰减：（1）使用温度依赖模型，输入来自热机械冰流模型;（2）使用雷达方法，线性近似几何校正的返回功率与冰厚度。这两种方法给出了不同的结果。我们认为，使用模拟的温度剖面计算的衰减比广泛使用的雷达方法更强大，特别是在深度平均衰减空间变化的位置，或在那里的基础反射率的模式与冰厚的模式相关。
Abstract Radar power returned from the basal interface along a 42 km long profile over an ice-rise promontory and the adjacent Roi Baudouin ice shelf, Dronning Maud Land, East Antarctica, is analyzed to infer spatial variations in basal reflectivity and hence the basal environment. Extracting basal reflectivity from basal returned power requires an englacial attenuation model. We estimate attenuation in two ways: (1) using a temperature-dependent model with input from thermomechanical ice-flow models; and (2) using a radar method that linearly approximates the geometrically corrected returned power with ice thickness. The two methods give different results. We argue that attenuation calculated using a modeled temperature profile is more robust than the widely used radar method, especially in locations where depth-averaged attenuation varies spatially or where the patterns of basal reflectivity correlate with the patterns of the ice thickness.