Climate of the Greenland ice sheet using a high-resolution climate model - Part 2: Near-surface climate and energy balance
Climate of the Greenland ice sheet using a high-resolution climate model - Part 2: Near-surface climate and energy balance
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DOI：
10.5194/tc-4-529-2010
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发表时间：
2010-01-01
期刊：
影响因子：
5.2
通讯作者：
van de Berg, W. J.
中科院分区：
文献类型：
--
作者：
Ettema, J.;van den Broeke, M. R.;van de Berg, W. J.
利用1958-2008年期间区域大气气候模式的输出，给出了格陵兰冰盖上近地表变量和地表能量平衡分量的空间变异性。冰盖近地表温度受地表高度、纬度、经度、大小平流、夏季融化的发生和中尺度地形特征的影响。由于地表持续的长波冷却，大气边界层的特点是温度逆温很强。与平缓倾斜的表面相结合，辐射损失保持了持续的卡特式风。这种辐射热损失主要由向地表输送的湍流感热来平衡。在夏季，地表接近辐射平衡，导致风速较低。吸收短波辐射和重新冻结融化的水所产生的正的次表层热流是地表升华和融化的热源。最强的温度差(>；13℃)出现在东北坡，那里有最强的绝热风(>；9ms(-1))和最低的相对湿度(
The spatial variability of near-surface variables and surface energy balance components over the Greenland ice sheet are presented, using the output of a regional atmospheric climate model for the period 1958-2008. The model was evaluated in Part 1 of this paper.The near-surface temperature over the ice sheet is affected by surface elevation, latitude, longitude, large-scale and small-scale advection, occurrence of summer melt and mesoscale topographical features. The atmospheric boundary layer is characterised by a strong temperature inversion, due to continuous longwave cooling of the surface. In combination with a gently sloping surface the radiative loss maintains a persistent katabatic wind. This radiative heat loss is mainly balanced by turbulent sensible heat transport towards the surface. In summer, the surface is near radiative balance, resulting in lower wind speeds. Absorption of shortwave radiation and a positive subsurface heat flux due to refreezing melt water are heat sources for surface sublimation and melt.The strongest temperature deficits (>13 degrees C) are found on the northeastern slopes, where the strongest katabatic winds (>9 ms(-1)) and lowest relative humidity (