Dynamics of the Midlatitude Circulation and Implications for a Changing Climate

中纬度环流的动态及其对气候变化的影响

• 批准号: 1144302
• 负责人: Geoffrey Vallis
• 金额: $ 60.63万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1144302&HistoricalAwards=false
• 关键词: Dynamics; Midlatitude; Circulation; Implications; Changing

This project studies the dynamical processes responsible two fundamental aspects of the general circulation of the atmosphere: the central latitude of the midlatitude jet streams and their accompanying storm tracks and surface westerlies, and the height and sharpness of the midlatitude tropopause. The work considers both the climatological mean jet position and tropopause height, and the changes in position and height that are likely to occur due to the overall warming of the atmosphere by greenhouse gas increases. Research on the latitude of the jet streams will consider, among other things, the interaction between the eddy-driven jets associated with the storm tracks, and the subtropical jets found on the poleward flanks of the Hadley cells. Research on the tropopause will consider the importance of atmospheric radiation balance in determing its height and sharpness, rather than the mixing effect of wavy atmospheric motions associated with the storm tracks. Jet latitude and tropopause height are closely associated, as previous research shows that each can influence the other. Research will be conducted through a hierarchy of atmospheric models, starting from the simplest possible numerical framework and progressing to comprehensive, state-of-the-art climate models.The work will, if successful, lead to improved understanding of the climate system and its response to changes in forcing, and so contribute toward improved predictions of the societal impacts of increasing greenhouse gas concentrations. The work will also have broader impacts through the teaching and outreach activities of the principal investigators. In addition, the project will fund and train a graduate student, thereby providing for the future scientific workforce in the area of atmospheric general circulation and climate dynamics.

该项目研究影响大气环流两个基本方面的动力过程：中纬度急流的中心纬度及其伴随的风暴路径和表面西风带，以及中纬度对流层顶的高度和锐度。 这项工作考虑了气候平均急流位置和对流层顶高度，以及由于温室气体导致大气整体变暖而可能发生的位置和高度的变化。 对急流纬度的研究将考虑与风暴路径相关的涡流驱动急流与哈德利环流极向侧翼发现的亚热带急流之间的相互作用。 对流层顶的研究将考虑大气辐射平衡在确定其高度和锐度方面的重要性，而不是与风暴路径相关的波浪状大气运动的混合效应。 急流纬度和对流层顶高度密切相关，之前的研究表明，两者可以相互影响。 研究将通过一系列大气模型进行，从最简单的数值框架开始，逐步发展到最先进的综合气候模型。这项工作如果成功，将提高对气候系统及其对强迫变化的响应的理解，从而有助于改进对温室气体浓度增加的社会影响的预测。 这项工作还将通过主要研究人员的教学和推广活动产生更广泛的影响。 此外，该项目还将资助和培训一名研究生，从而为大气环流和气候动力学领域的未来科学劳动力提供支持。