Initial Value Problem Theory of Cyclogenesis and the Predictability of Flows

该项目的总体目标是更好地了解天气尺度天气系统的发展，这可能最终导致改善天气预报。首席研究员之前的工作集中在流动的结构，或“初始值”，如何对扰动的后续发展做出贡献。他将沿着两条路线扩展这项研究。第一个任务是继续他对造成气旋形成的物理机制的研究；另一个是探索大尺度大气流动的可预测性。观测证据表明，背景大气气流中的变形和切变对某些类型的气旋形成起着重要作用。首席研究员已经展示了背景气流中的切变对气旋能量发展的影响。他将扩展这项工作，以观察汇合和分散对流动扰动的影响。虽然这一主题已被广泛研究，但对大气可预测性的理论估计仍然相差很大，数值天气预报实验的结果也是如此。原因似乎是流动状态的可预测性的可变性，也就是说，某些类型的流动本质上比其他类型的流动更可预测。首席研究员将探索数值模型中误差的增长，并试图区分那些可预测的流动和那些不能作为流动特性函数的流动。

The overall goal of this project is to better understand the development of synoptic scale weather systems, which may ultimately lead to improved weather forecasts. The principal investigator's previous work has focused how the structure of the flow, or "initial value", contributes to subsequent development of perturbations. He will extend this research along two lines. The first thrust is to continue his investigations into the physical mechanism(s) responsible for cyclogenesis; the other is to explore the predictability of large scale atmospheric flows. Observational evidence suggests that deformation, as well as shear, in the background atmospheric flow plays an important role for certain types of cyclogenesis. The principal investigator already has shown the effect of shear in the background flow on the energetic development of cyclones. He will extend this work to look at the effect of confluence and difluence on perturbations in the flow. While the subject has been studied extensively, theoretical estimates of the predictability of the atmosphere still vary widely as do the results from numerical weather prediction experiments. The reason appears to be variability in the predictability of the flow regimes, that is, certain types of flows are inherently more predictable than others. The principal investigator will explore the growth of error in numerical models and attempt to distinguish between those flows which are predictable and those which are not as a function of flow characteristics.