Atmospheric Blocking: Dynamics and Responses to Climate Change

大气阻塞：气候变化的动态和响应

• 批准号: 1552385
• 负责人: Zhiming Kuang
• 金额: $ 54.04万
• 依托单位: Harvard 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: 2016-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1552385&HistoricalAwards=false
• 关键词: Atmospheric; Blocking; Dynamics; Responses; Climate

Atmospheric blocking events are an important contributor to high impact extreme weather events. Improving the forecasts of blocking events and assessing how the frequency, severity, and location of such events may change with climate change are of substantial societal importance. Synoptic eddies have been shown to play a critical role in the dynamics of atmospheric blocking events by maintaining the blocking pattern but the understanding of their role is currently not sufficiently complete and quantitative. The goals of the proposed research are 1) to improve the dynamical understanding of atmospheric blocking events through developing a quantitative assessment of synoptic-eddy forcing of blocks. 2) to employ this dynamical understanding to investigate how blocking events will change with climate change and how blocks can be better simulated in climate and weather models. The proposed research will employ numerical experiments with a hierarchy of general circulation models, reanalysis data, and archived results of full-physics general circulation models such as Coupled Model Intercomparison Project models. The research has three components: the first is to study the eddy-forcing mechanism using idealized modeling experiments which to isolate and develop a quantitative understanding of this mechanism. The same idealized framework will be used to investigate how the speed and latitude of jet streams, different patterns of quasi-stationary planetary waves, and moisture modulate this mechanism. The second component is to test this understanding using the reanalysis data and to gain further insight into the dynamic of observed blocking events. The third component is to apply this understanding to examine the performance of full-physics models in simulating blocking, and to provide a more reliable and conclusive prediction on how blocking events will change in the future.

大气阻塞事件是导致高影响极端天气事件的重要原因。改善阻止事件的预测并评估此类事件的频率，严重性和位置如何随着气候变化而变化，这非常重要。概念涡流已被证明通过保持阻塞模式在大气阻塞事件的动力学中起着至关重要的作用，但对其作用的理解目前尚不完全完整和定量。拟议的研究的目标是1）通过对块的天气码头强迫进行定量评估，以提高对大气阻塞事件的动态理解。 2）采用这种动态理解来研究阻塞事件将如何随气候变化而变化，以及如何在气候和天气模型中更好地模拟块。拟议的研究将采用数值实验，该实验通过一般循环模型，重新分析数据的层次结构以及全相物理通用循环模型的存档结果，例如耦合模型比较项目模型。该研究具有三个组成部分：第一个组成部分是使用理想化的建模实验研究涡流机制，以隔离和发展对该机制的定量理解。相同的理想化框架将用于研究喷气流的速度和纬度如何，准平台行星波的不同模式以及水分调节这种机制。第二个组成部分是使用重新分析数据测试这种理解，并进一步了解观察到的阻塞事件的动态。第三个组成部分是运用这种理解来检查全物理模型在模拟阻塞时的性能，并为阻止事件如何在将来如何变化提供更可靠和结论性的预测。