CAREER: Exploring the Role of Vapor Buoyancy in Clouds, Circulation and Climate

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。与干燥空气相比，水蒸气的浮力效应源于其较低的分子量。由于水蒸气是地球大气中的一种微量气体，其浮力效应通常被认为是微不足道的。因此，在气候和大尺度动力学的研究中，它被忽视了。然而，首席研究员（PI）最近表明，由于水蒸气的浮力效应，冷空气在热带自由对流层中上升-这一发现需要对该主题给予更多关注。因此，为了促进我们对蒸汽浮力的理解，这项工作将研究蒸汽浮力如何影响热带大气中的温度，云和环流。该项目将有助于减轻未来气候变化的不确定性，并改善气候模型中蒸汽浮力的代表性。此外，该项目将创建新的大学课程材料，并建立一个教育计划，为萨克拉门托地区的高中和大学生提供积极的学习经验，他们大多来自代表性不足的群体。该项目将检验这样一种假设，即蒸汽浮力使热带大气的干燥地区升温，从而影响向外的长波辐射、静态稳定性、云的分布，从而影响气候敏感性。研究方法包括分析卫星观测，进行不同复杂性的数值模拟，并诊断最先进的气候模拟。该教育计划将通过实施动手旋转罐实验来改善大学和K-12水平的大气和气候教学。对于大学生，PI将开发关于水蒸气如何影响大规模环流的新课程模块和课程项目，补充主要关注干动力学的现有材料。PI还将为萨克拉门托地区的高中教师组织培训讲习班。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).The buoyancy effect of water vapor arises from its lower molecular mass compared to dry air. Because water vapor is a trace gas in Earth’s atmosphere, its buoyancy effect is often considered to be negligibly small. It is thus overlooked in studies of climate and large-scale dynamics. However, the principal investigator (PI) has recently shown that cold air rises in the tropical free troposphere due to this buoyancy effect of water vapor – a finding that calls for greater attention on the topic. Hence, to advance our understanding of vapor buoyancy, the work will investigate how vapor buoyancy affects temperature, clouds, and circulation in the tropical atmosphere. This project will help mitigate the uncertainty surrounding future climate change and improve the representation of vapor buoyancy in climate models. Additionally, the project will create new college course materials and establish an education program that provide active learning experiences for high school and university students in the Sacramento area, who are mostly from underrepresented groups. The project will test the hypothesis that vapor buoyancy warms the dry regions of the tropical atmosphere, which can subsequently affect outgoing longwave radiation, static stability, cloud distribution and, thereby, climate sensitivity. The research approach includes analyzing satellite observations, performing numerical simulations of varying complexity, and diagnosing state-of-art climate simulations. The education program will improve teaching on atmosphere and climate at both the university and K-12 levels by implementing hands-on rotating tank experiments. For university students, the PI will develop new course modules and class projects on how water vapor influences large-scale circulations, complementing existing materials that mainly focus on dry dynamics. The PI will also organize training workshops for high-school teachers in the Sacramento area.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.