Near-surface climate and surface energy budget of Larsen C ice shelf, Antarctic Peninsula
Near-surface climate and surface energy budget of Larsen C ice shelf, Antarctic Peninsula
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DOI：
10.5194/tc-6-353-2012
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发表时间：
2011-10
期刊：
影响因子：
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通讯作者：
P. K. Munneke;M. Broeke;J. King;T. Gray;C. Reijmer
中科院分区：
文献类型：
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作者：
P. K. Munneke;M. Broeke;J. King;T. Gray;C. Reijmer
分析了2009年1月22日至2011年2月1日南极拉森C冰架上两个自动气象站（AWS）收集的数据，并将其用作计算表面能量预算（SEB）模型的输入，其中包括融化能量。这两个AWS在南北方向上相隔约70 km，近地面气象和SEB显示出相似性，尽管可以看到所有组分（最明显的是熔体通量）的微小差异。短波辐射的次表层反射对融化和雪温的影响是显著的，并进行了讨论。在冬季，地面的长波冷却完全由感热的向下湍流输送来补偿。在夏季，正的净辐射通量被融化补偿，并经常被向上的热量和水分湍流扩散补偿，导致冰架上空的升华和弱对流。2010年11月是突出的，当强大的西风流在南极半岛导致了干燥和温暖的风在冰架，造成温暖和阳光充足的条件。在这些条件下，短波和感热通量的增加大于净长波和潜热通量的减少，为显著融化提供能量。
Data collected by two automatic weather stations (AWS) on the Larsen C ice shelf, Antarctica, between 22 Jan- uary 2009 and 1 February 2011 are analyzed and used as input for a model that computes the surface energy budget (SEB), which includes melt energy. The two AWSs are sep- arated by about 70 km in the north-south direction, and both the near-surface meteorology and the SEB show similarities, although small differences in all components (most notably the melt flux) can be seen. The impact of subsurface absorp- tion of shortwave radiation on melt and snow temperature is significant, and discussed. In winter, longwave cooling of the surface is entirely compensated by a downward turbulent transport of sensible heat. In summer, the positive net radia- tive flux is compensated by melt, and quite frequently by up- ward turbulent diffusion of heat and moisture, leading to sub- limation and weak convection over the ice shelf. The month of November 2010 is highlighted, when strong westerly flow over the Antarctic Peninsula led to a dry and warm f¨ ohn wind over the ice shelf, resulting in warm and sunny conditions. Under these conditions the increase in shortwave and sensi- ble heat fluxes is larger than the decrease of net longwave and latent heat fluxes, providing energy for significant melt.