Collaborative Research: Timescales for Large-Scale Tropospheric Transport - Inversions of Trace-Gas Measurements and Connections with Dynamics

臭氧、水蒸气、二氧化碳和气溶胶在低层大气中的分布受输送的强烈影响。量化这种传输对于理解和预测空气质量、气候变化和平流层臭氧消耗至关重要。这个合作项目将结合使用微量气体测量和模型模拟。这一努力还将促进研究生和博士后的培训和学习。本研究的材料。该研究的材料将被纳入约翰霍普金斯大学（JHU）研究生教育和研究培训（IGERT）关于水、气候和健康的综合计划的核心课程，以及约翰霍普金斯大学和哥伦比亚大学的教师培训课程。这项研究的结果将在国际科学会议上广泛传播，发表在同行评议的期刊上，并在网站上发布非技术报告。一个特别重要的量是从北半球人口稠密地区运输的过境时间分布（TTD），那里有大量污染物及其前体的排放。最大熵反演将与地面和飞机痕量气体测量一起使用，以约束TTDs。这些数据约束的TTDs将与化学输运模式模拟和气象分析相结合，以检查季节和年际变化以及与大气动力学的联系。化学气候模式整合将用于探索运输如何随气候变化。具体而言，本项目将提供以下数据：(1)对自空气最后一次与北半球大陆区域接触以来的TTDs进行有数据约束的估计，包括季节和年际变化；(2)对流层输运时间尺度的关键动力学控制知识；(3)了解对流层运输如何随气候变化而变化。综合起来，这些将从根本上解开化学和运输在形成对流层组成中的作用，对理解空气质量、气候变化和平流层臭氧具有重要意义。

The distribution of ozone, water vapor, carbon dioxide and aerosols in the lower atmosphere are strongly influenced by transport. Quantifying this transport is central to understanding and predicting air quality, climate change, and stratospheric ozone depletion. This collaborative project will use a combination of trace gas measurements and model simulations. The effort will also promote training and learning of graduate students a a postdoctoral fellow. Material from this research. Materials from the research will be included in a core course for the Johns Hopkins University (JHU) Integration of Graduate Education and Research Training (IGERT) program on Water, Climate and Health, as well as teacher training courses at JHU and Columbia University. The results of the research will be widely disseminated at international science meetings, publishing in peer-reviewed journals, and posts of non-technical reports on websites.A particularly important quantity is the transit-time distribution (TTD) for transport from Northern Hemisphere populated regions, where there are large emissions of pollutants and their precursors. Maximum entropy inversions will used together with surfaceand aircraft trace gas measurements to constrain the TTDs. These data-constrained TTDs will be combined with chemical transport model simulations and meteorological analyses to examine seasonal and interannual variations, and connections with atmospheric dynamics. Chemistry climate model integrations will be used to explore how the transport changes with climate. Specifically, this project will provide the following: (1) data-constrained estimates of the TTDs since air was last in contact with Northern Hemisphere continental regions, including seasonal and interannual variations; (2) knowledge of the key dynamical controls on tropospheric transport timescales; and (3) an understanding of how tropospheric transport may change in response to climate. In combination these will allow a fundamental disentangling of the roles of chemistry and transport in shaping the composition of the troposphere, with important implications for understanding of air quality, climate change, and stratospheric ozone.