A theoretical interpretation of numerically generated probability density functions (PDFs) of intermittent plasma transport events in unforced zonal flows is provided within the Charney-Hasegawa-Mima (CHM) model. The governing equation is solved numerically with various prescribed density gradients that are designed to produce different configurations of parallel and anti-parallel streams. Long-lasting vortices form whose flow is governed by the zonal streams. It is found that the numerically generated PDFs can be matched with analytical predictions of PDFs based on the instanton method by removing the autocorrelations from the time series. In many instances the statistics generated by the CHM dynamics relaxes to Gaussian distributions for both the electrostatic and vorticity perturbations, whereas in areas with strong nonlinear interactions it is found that the PDFs are exponentially distributed.
翻译:在Charney-Hasegawa-Mima(CHM)模型中提供了对非强制地区流中间流等离子体传输事件的数值生成概率密度函数(PDFs)的理论解释。调节方程式用各种规定的密度梯度进行数字解析,这些梯度旨在产生平行流和反平行流的不同配置。流动受区域流管理的长效浮质形式。发现数字生成的PDFs可以与基于瞬时法的PDFs分析预测相匹配,方法是从时间序列中去除自动反差。在许多情况下,CHM动态生成的统计数据可以向高斯分布的电静态和多色性扰动,而在有强烈非线性互动的地区,发现PDFs是指数分布的。