Influence of Persistent Wind Scour on the Surface Mass Balance of Antarctica
Influence of Persistent Wind Scour on the Surface Mass Balance of Antarctica
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DOI：
10.1038/ngeo1766
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发表时间：
2013-05
影响因子：
18.3
通讯作者：
Indrani DasH;R. Bell;T. Scambos;M. Wolovick;T. Creyts;M. Studinger;N. Frearson;J. Nicolas;J. Lenaerts;M. Broeke
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作者：
Indrani DasH;R. Bell;T. Scambos;M. Wolovick;T. Creyts;M. Studinger;N. Frearson;J. Nicolas;J. Lenaerts;M. Broeke
准确量化南极表面积雪是估计南极物质平衡以及对冰芯记录进行气候解释的关键制约因素。在南极洲上空，近地表的风沿着相对陡峭的地表斜坡加速，侵蚀和升华了雪。这种风力冲刷导致许多局部区域(≤200 平方公里)，减少了地表堆积，，，。南极表面物质平衡的估计依赖于稀疏点测量或粗略大气模型，这些模型没有捕捉到这些局部过程，并高估了风冲区的净质量输入。在这里，我们结合了对不整合地层的机载雷达观测和激光雷达获取的表面粗糙度测量，以确定东南极腹地Dome A上空广泛的风冲区。冲刷带是持久的，因为它们受基岩地形控制。在Dome A观测的基础上，我们开发了一个经验模式来预测整个南极大陆的风蚀带，发现这些带主要位于南极东部。我们估计，由于风的冲刷，南极2.7%-6.6%的表面积具有持续的负净积累，这表明，在目前的地表质量平衡计算中，整个大陆的雪量输入被高估了11-36.5GT yr−1。
Accurate quantification of surface snow accumulation over Antarctica is a key constraint for estimates of the Antarctic mass balance, as well as climatic interpretations of ice-core records,. Over Antarctica, near-surface winds accelerate down relatively steep surface slopes, eroding and sublimating the snow. This wind scour results in numerous localized regions (≤200 km2) with reduced surface accumulation,,,,. Estimates of Antarctic surface mass balance rely on sparse point measurements or coarse atmospheric models that do not capture these local processes, and overestimate the net mass input in wind-scour zones. Here we combine airborne radar observations of unconformable stratigraphic layers with lidar-derived surface roughness measurements to identify extensive wind-scour zones over Dome A, in the interior of East Antarctica. The scour zones are persistent because they are controlled by bedrock topography. On the basis of our Dome A observations, we develop an empirical model to predict wind-scour zones across the Antarctic continent and find that these zones are predominantly located in East Antarctica. We estimate that ∼ 2.7–6.6% of the surface area of Antarctica has persistent negative net accumulation due to wind scour, which suggests that, across the continent, the snow mass input is overestimated by 11–36.5 Gt yr−1in present surface-mass-balance calculations.