Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT, United Kingdom.
Phys Rev Lett. 2013 Mar 8;110(10):104502. doi: 10.1103/PhysRevLett.110.104502. Epub 2013 Mar 5.
We present direct statistical simulation of jet formation on a β plane, solving for the statistics of a fluid flow via an expansion in cumulants. Here we compare an expansion truncated at second order (CE2) to statistics accumulated by direct numerical simulations. We show that, for jets near equilibrium, CE2 is capable of reproducing the jet structure (although some differences remain in the second cumulant). However, as the degree of departure from equilibrium is increased (as measured by the zonostrophy parameter), the jets meander more and CE2 becomes less accurate. We discuss a possible remedy by inclusion of higher cumulants.
我们在β平面上呈现射流形成的直接统计模拟，通过累积量展开来求解流体流动的统计数据。在这里，我们将二阶截断展开（CE2）与直接数值模拟累积的统计数据进行比较。我们表明，对于接近平衡的射流，CE2 能够再现射流结构（尽管在第二累积量中仍然存在一些差异）。然而，随着偏离平衡的程度增加（以纬向度参数衡量），射流变得更加曲折，CE2 的准确性降低。我们通过包含更高阶累积量来讨论一种可能的补救方法。
