Observing and Modeling the Upper-Troposphere-Lower-Stratosphere Moistening Processes across Scales

跨尺度对流层上层-平流层下层湿润过程的观测和建模

• 批准号: 2140235
• 负责人: Paul Staten
• 金额: $ 50.52万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2140235&HistoricalAwards=false
• 关键词: Observing; Modeling; Upper; Troposphere; Lower

Though quiescent compared to the troposphere below, the stratosphere influences life at the surface in important ways (like blocking harmful UV rays), each dependent on stratospheric water vapor. The primary source of water vapor in the lower stratosphere comes from the tropics, where year-round heating of the ocean surface by the sun fuels some of the world's most intense storms. Tropical thunderstorms loft water vapor into the upper troposphere. Whatever water vapor that is not freeze-dried at the cold point tropopause – the thermal boundary between the troposphere and the stratosphere – is free to enter the stratosphere, where it is distributed globally. However, most water vapor does not enter the stratosphere immediately above these storms, as this is also where the tropopause is coldest. Furthermore, the strongest storms do not necessarily occur over the warmest ocean surface. Leveraging the newly available high-resolution observations and a hierarchy of climate models, this project aims to better understand these issues involved in getting water vapor into the stratosphere. In collaboration with scientists at the National Center for Atmospheric Research (NCAR), the proposed activities will train a graduate student and involve the education programs at the investigator’s institution.This work will rely on state-of-the-art reanalyses, a hierarchy of numerical models, and the new COSMIC-II (Constellation Observing System for Meteorology Ionosphere and Climate II) fleet of global positioning system receivers to (1) examine how sea surface temperatures impact cold point tropopause (CPT) temperatures, (2) analyze the processes in the atmosphere that determine CPT temperature, and (3) determine when and where the CPT temperature matters most for stratospheric moisture uptake. The investigating team will first observe the relationships between sea surface temperature, CPT temperatures, and water vapor, then compare the observed relationships with those in model simulations. The team will also utilize numerical models to examine the impacts of resolution and sea surface temperature anomalies on CPT temperatures. In addition to being of interests to the climate science community, the emerging results on stratospheric change has implications for health and prosperity, as well as national defense (which was the original motivation for the study of stratospheric moisture and circulation during WWII). The proposed activities will support several outreach programs, including the training of K-12 teachers in Indiana through the Educating for Environmental Change initiative, and the recruitment of underrepresented minority students in Indiana through the Jim Holland Research Initiative in STEM Education.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

尽管与下方的对流层相比，平流层处于静止状态，但它以重要的方式影响地表生命（例如阻挡有害的紫外线），而每种方式都依赖于平流层的水蒸气。平流层低层水蒸气的主要来源来自热带地区，那里的海洋表面常年受到太阳的加热，助长了世界上一些最强烈的风暴。热带雷暴将水蒸气喷射到对流层上层。任何在对流层顶冷点（对流层和平流层之间的热边界）处未冻干的水蒸气都可以自由进入平流层，并在全球范围内分布。然而，大多数水蒸气不会进入这些风暴正上方的平流层，因为这也是对流层顶最冷的地方。此外，最强的风暴不一定发生在最温暖的海洋表面。利用新获得的高分辨率观测结果和气候模型层次结构，该项目旨在更好地了解水蒸气进入平流层所涉及的这些问题。与国家大气研究中心 (NCAR) 的科学家合作，拟议的活动将培训一名研究生，并涉及研究者机构的教育计划。这项工作将依靠最先进的再分析、数值模型层次结构和新的 COSMIC-II（气象电离层和气候星座观测系统 II）全球定位系统接收器组来 (1) 研究如何 海面温度影响冷点对流层顶 (CPT) 温度，(2) 分析大气中决定 CPT 温度的过程，(3) 确定 CPT 温度对平流层水分吸收最重要的时间和地点。调查小组将首先观察海面温度、CPT温度和水蒸气之间的关系，然后将观察到的关系与模型模拟中的关系进行比较。该团队还将利用数值模型来研究分辨率和海面温度异常对 CPT 温度的影响。除了引起气候科学界的兴趣外，平流层变化的新结果还对健康和繁荣以及国防产生影响（这是二战期间平流层水分和环流研究的最初动机）。拟议的活动将支持多项外展计划，包括通过环境变化教育计划对印第安纳州的 K-12 教师进行培训，以及通过吉姆·霍兰德 STEM 教育研究计划在印第安纳州招募代表性不足的少数族裔学生。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。