Statistics of an Unstable Barotropic Jet from a Cumulant Expansion
Statistics of an Unstable Barotropic Jet from a Cumulant Expansion
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累积量膨胀引起的不稳定正压射流的统计
DOI：
10.1175/2007jas2510.1
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
T. Schneider
中科院分区：
文献类型：
--
作者：
J. Marston;E. Conover;T. Schneider
研究了旋转球上正压气流的低阶等时统计特性。流动由线性松弛驱动，朝向不稳定的纬向急流。对于相对较短的弛豫时间，流动由临界层波主导。对于足够长的弛豫时间，流动是湍流。从二阶累积展开得到的统计数据进行比较，在直接数值模拟中积累的，揭示了不同的弛豫时间的扩展的优势和局限性。
Low-order equal-time statistics of a barotropic flow on a rotating sphere are investigated. The flow is driven by linear relaxation toward an unstable zonal jet. For relatively short relaxation times, the flow is dominated by critical-layer waves. For sufficiently long relaxation times, the flow is turbulent. Statistics obtained from a second-order cumulant expansion are compared to those accumulated in direct numerical simulations, revealing the strengths and limitations of the expansion for different relaxation times.