Collaborative Research: Nonlinear Stability of Zonally Varying Flows

这项研究的目的是为了更好地了解 大气扰动的非线性动力学和演变 嵌入在纬向变化的基流中。 这项研究将 使用β平面上的两层斜压模式和 球坐标正压模式 双层模型 将允许PI检查斜压，正压和 地形过程，并评估其在 的区域特征和时间变异性， 纬向气流和波浪扰动。 研究与 正压模式将评估使用球形 在模拟这些类型的流动几何。 在弱的情况下， 非线性，模型的解决方案将获得解析 使用渐近展开和多个空间和时间尺度。 在此限制之外，将使用光谱变换方法来 用数值方法求解。 这些调查可以提供 进一步了解这些观测到的大气特征， 区域性气旋生成、阻塞和低频变率。 该项目正在与下列机构合作开展： Terrence Nathan博士，爱荷华州州立大学，NSF资助 ATM-8813296

The goal of this research is to better understand the nonlinear dynamics and evolution of atmospheric disturbances embedded in a zonally varying basic flow. The research will be done using a two-layer baroclinic model on the beta-plane and a spherical coordinate barotropic model. The two-layer model will allow the PIs to examine baroclinic, barotropic and topographic processes and to assess the their combined role in determining the regional character and time variability of the zonal flow and wave disturbances. The research with the barotropic model will to assess the impact of using spherical geometry in simulating these types of flows. In cases of weak nonlinearity, model solutions will be obtained analytically using asymptotic expansions and multiple space and time scales. Outside this limit, spectral transform methods will be used to obtain solutions numerically. These investigations may provide further insight into such observed atmospheric features as regional cyclogenesis, blocking, and low frequency variability. This project is being carried out in collaboration with Dr. Terrence Nathan, Iowa State University, under NSF grant ATM-8813296.