Collaborative Research: A Global View of Topographically Bound Low Level Jets

合作研究：地形限制低空急流的全球视野

• 批准号: 1601623
• 负责人: Wayne Schubert
• 金额: $ 29.69万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601623&HistoricalAwards=false
• 关键词: Collaborative; Research; Global; View; Topographically

Topographically bound low-level jets are strong, persistent winds in the lower atmosphere associated with elevated terrain features such as mountain ranges and plateaus. Examples include the persistent northerly and southerly flows on opposite sides of the Rocky Mountains in North America and the Andes Mountains in South America, and the easterly flow that surrounds Antarctica. The goal of this project is to understand what causes these jets and to study their impacts on climate. Previous work developed a two-dimensional theory which explains such jets as a balanced dynamical response of the atmosphere in response to forcing by solar heating and infrared radiative cooling of the elevated terrain. Computed results using simplified terrain profiles showed qualitative agreement with observed winds in two-dimensional cross sections through the Andes and Antarctica. This project will extend the theory to three dimensions, taking into account the effects of the earth's spherical shape and the full shape of the elevated terrain. Solutions of the resulting equations will be computed using a novel numerical method which refines the grid where needed to obtain accurate solutions with minimal computational work. Solutions will be computed for jets associated with several regions of complex terrain around the globe, such as Antarctica, the Tibetan Plateau, Greenland, and the Rockies and Andes, and validated by comparison with observational data.Beyond developing our fundamental understanding of atmospheric dynamics, this work has societal relevance due to the importance of low-level jets for regional climate. For example, the Great Plains low-level jet is responsible for a substantial portion of the moisture transport into the eastern half United States which sustains agriculture, and the low-level jet off the eastern coast of Africa is a major component of the Indian monsoon which greatly affects many aspects of life in the Indian subcontinent. This project will also contribute to developing the future scientific workforce by supporting and training two graduate students in research, and training one undergraduate student in computational mathematics and modern scientific programming. Finally, the methods developed in this project will be made available to researchers in atmospheric dynamics through software codes, so that they can be applied to a wide array of scientific problems.

地形绑定的低级喷气式喷气式很强，在与高山脉和高原等地形特征相关的较低大气中持续的风。 例子包括北美落基山脉和南美安第斯山脉山脉的对面的持续北方和南方流动，以及南极洲周围的东方流动。该项目的目的是了解导致这些喷气机的原因并研究它们对气候的影响。 先前的工作开发了一种二维理论，该理论解释了这种喷气机，例如大气的平衡动力响应，响应太阳能加热和高架地形的红外辐射冷却。 使用简化的地形谱进行了计算的结果，显示了通过安第斯山脉和南极的二维横截面中观察到的风的定性一致性。 考虑到地球的球形形状和高架地形的完整形状的影响，该项目将将理论扩展到三个维度。 将使用一种新型的数值方法来计算所得方程的溶液，该方法在需要以最小的计算工作获得准确的解决方案的情况下完善了网格。 Solutions will be computed for jets associated with several regions of complex terrain around the globe, such as Antarctica, the Tibetan Plateau, Greenland, and the Rockies and Andes, and validated by comparison with observational data.Beyond developing our fundamental understanding of atmospheric dynamics, this work has societal relevance due to the importance of low-level jets for regional climate.例如，大平原低级喷气式飞机负责向美国东半部的大部分水分运输，该水分持续了农业，而非洲东海岸的低级喷气式飞机是印度季风的主要组成部分，这极大地影响了印度次陆地生命的许多方面。 该项目还将通过支持和培训两名研究生研究并培训一名计算数学和现代科学节目的本科生，从而有助于发展未来的科学劳动力。 最后，该项目中开发的方法将通过软件代码提供给大气动力学的研究人员，以便将其应用于各种科学问题。