Time Evolution of Baroclinic Wave Activity in Stormtracks and Its Relationship with Jetstream Structure

风暴路径中斜压波活动的时间演化及其与急流结构的关系

• 批准号: 8922132
• 负责人: John Wallace
• 金额: $ 6.61万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-05-15 至 1993-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8922132&HistoricalAwards=false
• 关键词: Time; Evolution; Baroclinic; Wave; Activity

In the Northern Hemisphere winter, most of the synoptic scale storm activity is observed in two widely-separated midlatitude stormtracks, along the east coasts of Asia and the United States. There is evidence that the variability in wave (or storm) activity and the position of the stormtrack are related to low frequency variability of the basic flow in which they are embedded. Further, it appears that the waves influence the evolution of the basic flow pattern. While much evidence has been gathered in an averaged sense, there is still a need to understand the time evolution of the interactions. The purpose of this research is to investigate the time evolution of synoptic scale waves and along the major stormtracks and to relate it to low-frequency changes in the basic flow, specifically the structure of the jetstream. The study employs a 30-year data set. This research has important implications for improving medium and long range weather forecasting. If time permits, the PIs will also examine the relationship between the low-level easterly jet over Africa and the so-called easterly or African waves.

在北半球冬季，大多数天气尺度的风暴活动是在两条相距很远的中纬度风暴路径上观测到的，它们沿着亚洲和美国的东海岸。有证据表明，波浪（或风暴）活动的可变性和风暴路径的位置与它们所在的基本流的低频可变性有关。此外，波浪似乎影响了基本流型的演变。虽然在平均意义上已经收集了许多证据，但仍然需要了解相互作用的时间演变。本研究的目的是探讨天气尺度波和主要风暴路径的时间演变，并将其与基本气流，特别是急流结构的低频变化联系起来。这项研究采用了一组30年的数据。本研究对提高中长期天气预报水平具有重要意义。如果时间允许，PIs还将研究非洲上空低空东风急流与所谓的东风或非洲波之间的关系。