Pitfalls in radar diagnosis of ice‐sheet bed conditions: Lessons from englacial attenuation models
Pitfalls in radar diagnosis of ice‐sheet bed conditions: Lessons from englacial attenuation models
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雷达诊断冰盖床状况的陷阱：冰川衰减模型的教训
DOI：
10.1029/2010gl046205
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发表时间：
2011
影响因子：
5.2
通讯作者：
K. Matsuoka
中科院分区：
文献类型：
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作者：
K. Matsuoka
从冰盖床返回的雷达功率已被广泛接受为床条件的指标。然而，床返回功率还取决于冰内衰减，这主要是冰温的函数。在这里，使用一维衰减模型，它表明，在大多数情况下，床返回功率的变化主要是由冰内衰减的变化，而不是床反射率。积累速率和地热通量异常都可能干扰解释。因此，已被广泛接受的分析雷达算法可能会产生湿/干床的错误描绘。在诊断床况时需要更仔细的考虑。浅层冰内雷达反射体的空间分布可以作为积累率的代表，而积累率会影响冰温，从而影响返回功率。我认为，有必要同时解释返回功率和englacial-reflector模式，以提高床诊断。
Radar power returned from ice‐sheet beds has been widely accepted as an indicator of bed conditions. However, the bed returned power also depends on englacial attenuation, which is primarily a function of ice temperature. Here, using a one‐dimensional attenuation model, it is demonstrated that, in most cases, variations in bed returned power are dominated by variations in englacial attenuation, rather than bed reflectivity. Both accumulation rate and geothermal flux anomalies can interfere with the interpretation. With the consequence, analytical radar algorithms that have been widely accepted likely yield false delineations of wet/dry beds. More careful consideration is needed when diagnosing bed conditions. Spatial patterns of shallow englacial radar reflectors can be used as a proxy for accumulation rates, which affect ice temperature and thus returned power. I argue that it is necessary to simultaneously interpret the returned power and englacial‐reflector patterns to improve the bed diagnosis.