Theory of Trace Gas Distributions in the Lower Stratosphere and Near the Tropopause

这项研究的目的是推进全球范围内的示踪气体传输和示踪气体分布的理论，以及示踪剂-示踪剂的关系。 现有的理论已经相当成功地描述了全球跟踪分布在平流层和解释不同的示踪剂示踪剂的关系，在热带和midlatitutde平流层和冬季极涡的部分孤立的地区。 然而，现有的理论还没有得到充分的发展，无法利用这些非常紧凑且可重复的关系的全部信息内容，此外，该理论在对流层顶附近失败，在那里，痕量气体混合比的大垂直梯度使一些基本假设无效。为了解决这些问题，理论的发展与痕量气体输运的建模，模型的结果既指导理论的发展，并提供理论预测的测试。 四项主要任务是：（1）修改现有理论，使理论在对流层顶附近和通过对流层顶有效，（2）研究控制由示踪气体定义的对流层顶的位置和形状的因素，（3）澄清总的全球示踪气体通量和示踪剂-示踪剂关系的形状之间的关系，（4）示踪关系的非紧性分析。更广泛的影响集中在培养年轻科学家从事这类科学活动方面。这项培训涉及一名博士后学者通过直接参与工作;研究生参加主要研究员关于平流层气象学和运输的常规课程，其中将纳入最新的工作成果;以及本科生，他们有机会通过麻省理工学院的本科生研究机会计划参与工作的组成部分。

The aim of this research is to advance the theory of trace gas transport and trace gas distributions on the global scale, and of tracer-tracer relationships. Existing theory has been quite successful in describing global trace distributions in the stratosphere and in explaining the observed different tracer-tracer relationships in the partly isolated regions of the tropical and midlatitutde stratosphere and the wintertime polar vortex. Yet existing theory has not been sufficiently well developed to exploit the full information content of these remarkably compact and reproducible relationships and, moreover, the theory fails near the tropopause where large vertical gradients of trace gas mixing ratios render some of the underlying assumptions invalid. To address these issues, theoretical development is conducted in concert with modeling of trace gas transport, the model results both guiding the theoretical development and providing tests of theoretical predictions. The four main tasks are: (1) modification of existing theory to render the theory valid near and through the tropopause, (2) investigation of factors controlling the location and shape of the tropopause as defined by trace gases, (3) clarification of the relationship between gross global trace gas fluxes and the shape of tracer-tracer relationships, and (4) analysis of non-compactness in tracer relationships.Broader impacts center on training of young scientists in this type of scientific activity. This training involves a postdoctoral scholar through direct involvement in the work; graduate students taking the principal investigator's regular course on stratospheric meteorology and transport, which will incorporate the latest results of the work; and undergraduates who are offered the opportunity to involve in components of the work through MIT's Undergraduate Research Opportunities Program.