Stratospheric Anticyclones and their Interactions with the Troposphere

该项目旨在提高我们对反气旋或高压系统（北半球/南半球的顺时针/逆时针旋转环流）的理解，这些系统位于地球表面以上10-50公里的大气层中，被称为平流层。这些平流层反气旋，包括北半球的阿留申高压和大西洋高压以及南半球的澳大利亚高压，与每个半球冬季极点的平流层极地涡旋（低压系统）以及在地球表面附近产生冷空气爆发的天气系统共同演化。该项目的结果将有助于揭示平流层过程，并改进它们对具有社会重要性和高影响的天气事件（如冷空气爆发和冬季风暴）的预测。本项目资助1名博士后和1名本科生，为培养下一代科学家做出贡献。该项目的研究方法将在PI教授的课程中使用，从而将这些方法介绍给参与该项目的学生之外的更多学生。将使用具有各种特殊设计配置（例如，有/没有地形）的大气模型进行数值实验，以揭示大陆尺度近地表温度异常发生的条件，这些异常单独或与扰乱极地涡旋的平流层过程共同作用。数值实验还将用于揭示导致不同地理区域近地面冷空气爆发的平流层温度异常模式。该项目将对平流层环流系统及其与地球表面天气的耦合产生根本性的新见解，包括关于近地表冷空气爆发及其受平流层过程调节的新知识。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The project aims to advance our understanding of anticyclones or high pressure systems (clockwise/counterclockwise turning circulations in the Northern/Southern Hemisphere) in the layer of the atmosphere within 10-50 km above the earth's surface, which is called as Stratosphere. These stratospheric anticyclones, including the Aleutian High and Atlantic High of the Northern Hemisphere, and Australian High in the Southern Hemisphere, are co-evolved with the stratospheric polar vortex (low-pressure systems) over each hemisphere's winter pole as well as weather systems that produce cold-air outbreaks near the earth's surface. The outcome of the project would help reveal stratospheric processes and improve their predictions societally important and high-impact weather events, such as cold-air outbreaks and winter storms. This project supports a post-doctoral fellow and undergraduate student, contributing to the training of next generation of scientists. The project's research methods will be used in courses taught by the PI, thus introducing these methods to a larger body of students outside of those working on the project. Numerical experiments with an atmospheric model with various specially designed configurations (e.g., with/without topography) will be used to reveal the conditions under which continental scale near-surface temperature anomalies would occur, acting alone or in concert with the stratospheric processes that disturb the polar vortex. Numerical experiments will also be used to disclose the patterns of stratospheric temperature anomalies that lead to near-surface cold-air outbreaks in different geographical regions. The project will yield fundamental new insights into stratospheric circulation systems and their coupling with the weather at the earth's surface, including new knowledge about near-surface cold-air outbreaks and their regulation by stratospheric processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.