Downstream Development over the North Pacific Ocean

预测温带“产生天气的”扰动的一个重要问题是了解这些特征如何从一个地方传播到另一个地方。例如，北美的日常天气模式受到源自北太平洋并随后向东传播的天气尺度扰动的影响。这种扰动如何以及在何种情况下迅速向下游扩散，影响了北美的天气，这是一个公开而重要的问题。哈基姆博士将检验他的假设，即北太平洋急流的结构特性，如风和温度的水平和垂直剖面，会影响下游对气旋形成事件的反应，因为气流特性控制着波浪的生长和传播方式。该研究将包括诊断北太平洋西部发生的气旋形成事件演变的观测结果，确定有利于下游发展的流动模式，分析此类事件的操作模型误差特征，并使用理想化的纬向变化喷射流模拟下游发展。这些结果可作为今后有关北美大陆上游有针对性和加强的观测的研究的基础。

An important problem in forecasting extratropical "weather-producing" disturbances involves understanding how these features propagate from one location to another. For example, daily weather patterns over North America are influenced by synoptic-scale disturbances that originate over the North Pacific Ocean and subsequently propagate eastward. Exactly how and under circumstances this rapid downstream spreading of disturbances affects the weather over North America is an open and important question. Dr. Hakim will test his hypothesis for how this occurs, namely that the structural properties of the North Pacific jet stream, such as the horizontal and vertical profiles of wind and temperature, affect the downstream response to cyclogenesis events since the flow properties control how the waves grow and propagate. The study will include diagnosing observations of the evolution of cyclogenesis events occurring over the western North Pacific ocean and identifying flow regimes conducive for downstream development, analyzing operational model error characteristics for such events, and modeling downstream development using idealized zonally varying jet streams. The results may serve as a basis for future studies concerned with targeted and enhanced observations upstream from the North American continent.