Nonlinear Stability of Zonally Varying Flows

本研究的目的是为了更好地理解在纬向变化的基本气流中嵌入的大气扰动的非线性动力学和演化。研究将采用β平面上的两层斜压模型和球坐标正压模型。双层模式将允许pi检查斜压、正压和地形过程，并评估它们在确定纬向流和波浪扰动的区域特征和时间变化方面的综合作用。正压模型的研究将评估使用球面几何来模拟这些类型的流动的影响。在弱非线性的情况下，利用渐近展开式和多空间和时间尺度解析得到模型解。在此限制之外，将使用谱变换方法来获得数值解。这些研究可以进一步深入了解观测到的大气特征，如区域气旋形成、阻塞和低频变率。该项目由美国国家科学基金会（NSF）资助，由纽约州立大学奥尔巴尼分校的Arthur Loesch博士合作进行。

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 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 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. Arthur Loesch, SUNY-Albany, under NSF grant ATM-8813621.