Collaborative Research: Stratospheric Age in a Changing Climate: Connecting Theory, Models, and Observations

合作研究：气候变化中的平流层年龄：理论、模型和观测的联系

• 批准号: 1546585
• 负责人: Edwin Gerber
• 金额: $ 35.49万
• 依托单位: New York 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=1546585&HistoricalAwards=false
• 关键词: Collaborative; Research; Stratospheric; Age; Changing

Changes in the atmospheric circulation in response to anthropogenic forcing are expected to affect stratospheric water vapor and ozone recovery, with direct effects on surface temperatures, precipitation, and winds. Policy makers and the public rely on model projections of these changes. This research will develop strategies to validate model simulations with analytic theory, to identify and correct model biases, and to establish rigorous test to assess their fitness for climate projection. This project will also support the education and training of two graduate students. providing them the opportunity to develop a physical understanding of the atmospheric circulation and practical experience with high performance scientific computing.This project will connect theory, modeling, and observations of stratospheric transport. The Brewer-Dobson Circulation describes the transport of mass and trace gases through the stratosphere. In concert with chemical processes, it sets the distribution of water vapor and ozone through the middle atmosphere. Models nearly unanimously predict the Brewer-Dobson Circulation to increase in response to anthropogenic forcing, but the circulation cannot be observed directly, due to the slow time scale of overturning (on the order of years). In situ and satellite-based estimates of the "age of air," a measure of the transport time from the surface to stratosphere which can be estimated from observations of trace gases, however, do not robustly detect a change in transport. Some even suggest a weakening of the circulation, although large uncertainties imply that model trends are not inconsistent. The first goal of this project is to establish a connection between the stratospheric circulation and age distributions with three-dimensional atmospheric models. In particular, the latitudinal structure of age, which can be calculated directly from measurements of trace gases such as CO2 or SF6, will be related to the mean circulation of mass, which is diagnosed in climate model integrations. The second goal is to use these insights to evaluate stratospheric transport in numerical models, connecting standard tests of dynamical cores to the climatological properties of the circulation. Theoretical constraints on age transport will be used to detect biases in climate models arising from deficiencies in their representation of the circulation and/or tracer transport. The third and final goal is to evaluate the new tracer-transport diagnostics in the context of climate change.

对人为强迫的响应，大气循环的变化有望影响平流层水蒸气和臭氧回收，对表面温度，降水和风的直接影响。政策制定者和公众依靠这些变化的模型预测。这项研究将制定以分析理论验证模型模拟，识别和纠正模型偏见的策略，并建立严格的测试以评估其对气候投射的适合度。该项目还将支持两名研究生的教育和培训。为他们提供了对高性能科学计算的大气循环和实践经验的物理理解的机会。该项目将连接平流层运输的理论，建模和观察结果。 Brewer-Dobson循环描述了质量和痕量通过平流层的运输。与化学过程一致，它使水蒸气和臭氧的分布通过中间大气。模型几乎一致预测酿酒师循环会对人为强迫的响应增加，但是由于推翻的时间尺度缓慢（在几年的顺序上），无法直接观察到循环。原位和基于卫星的“空气年龄”的估计值是从表面到平流层的运输时间的量度，可以从痕量气体的观察结果中估算出来，但是，并不能强烈检测到运输的变化。尽管大型不确定性暗示模型趋势并不矛盾，但有些人甚至暗示了循环的削弱。该项目的第一个目标是通过三维大气模型在平流层循环与年龄分布之间建立联系。特别是，可以直接根据诸如CO2或SF6等痕量气体的测量值计算的年龄纬度结构与质量的平均循环有关，质量的平均循环是在气候模型积分中诊断出的。第二个目标是利用这些见解来评估数值模型中的平流层传输，将动态核心的标准测试与循环的气候特性联系起来。关于年龄运输的理论限制将用于检测因其在循环和/或示踪剂传输的代表时引起的气候模型中的偏见。第三个也是最终目标是在气候变化的背景下评估新的示踪剂传播诊断。