Second-moment budgets and mixing intensity in the stably stratified atmospheric boundary layer over thermally heterogeneous surfaces
Second-moment budgets and mixing intensity in the stably stratified atmospheric boundary layer over thermally heterogeneous surfaces
复制标题
热非均质表面稳定分层大气边界层的二阶矩预算和混合强度
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
P. Sullivan
中科院分区：
文献类型：
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作者：
D. Mironov;P. Sullivan
摘要采用大涡模拟（LES）方法，分析了下垫面水平温度非均质性对稳定分层边界层湍流结构和混合强度的影响。比较了固定风驱动流的理想LESs、均匀表面温度和非均匀表面温度。LES数据用于计算统计矩，估计湍流动能（TKE）、温度方差和温度通量的预算，并评估维持预算中各项的相对重要性。与以前的大多数研究不同，基于les的秒矩预算的估计充分考虑了亚电网规模的贡献。非均匀表面上的SBL湍流更大，方差（和TKE）更大，垂直混合更好，与均匀表面相比更深。两种情况之间最显著的差异表现在温度变化及其预算上。因为表面…
AbstractThe effect of horizontal temperature heterogeneity of the underlying surface on the turbulence structure and mixing intensity in the stably stratified boundary layer (SBL) is analyzed using large-eddy simulation (LES). Idealized LESs of flows driven by fixed winds and homogeneous and heterogeneous surface temperatures are compared. The LES data are used to compute statistical moments, to estimate budgets of the turbulence kinetic energy (TKE), of the temperature variance and of the temperature flux, and to assess the relative importance of various terms in maintaining the budgets. Unlike most previous studies, the LES-based second-moment budgets are estimated with due regard for the subgrid-scale contributions.The SBL over a heterogeneous surface is more turbulent with larger variances (and TKE), is better vertically mixed, and is deeper compared to its homogeneous counterpart. The most striking difference between the cases is exhibited in the temperature variance and its budget. Because of surfac...