RUI: Dynamical Coupling during Major Stratospheric Sudden Warming

一个主要的平流层突然变暖（SSW）以北半球冬季极涡的突然破裂为特征，可以引起中间层显著和意想不到的变化，最近的证据表明平流层顶在80公里处升高。平流层和中间层之间的联系可能与重力波（GWs）和行星波（PWs）有关，它们是时空谱两端的动力特征。在此背景下，本项目试图通过(1)表征平流层和中间层中GWs和PWs的来源/特性，以及(2)评估它们在驱动这种耦合和平流层顶升高中的作用和相互作用来阐明主要ssw的平流层-中间层耦合。它将采用三管齐下、多尺度的方法，以国家大气研究中心（NCAR）的全大气群落气候模型（WACCM）、俄克拉荷马大学的高级区域预测系统（ARPS）和观测为基础。利用WACCM，将对分解的行星尺度和参数化的GW强迫以及波致环流进行研究，波致环流增强了向平流层的示踪剂输送并影响了地表气候。在高空间分辨率下，ARPS模拟将明确地解析大部分GW活动直至中低层。通过ARPS，阐明的GW性质将有助于澄清其来源和在WACCM中看到的强迫。最后，将检查卫星观测和分析产品（具有推断和参数化的GW影响），并将其与模式结果进行比较。这项工作的广泛影响是多方面的。在过去十年中，对主要ssw的研究主要集中在它们对对流层的潜在影响上。通过扩大目前的观点，包括中间层和GWs的细节，可以通过该项目获得关于SSW演化的新见解。此外，相关的项目活动旨在丰富课堂内外的本科教育。参与的本科生将进行实验，分析模型和观测数据，并展示研究成果。最后，该项目提供本科生研究培训和接触尖端的地球物理研究，这一点(1)在类似的国家支持的文科院校可能无法获得，(2)在南卡罗来纳州和更大的东南地区是独一无二的。

Characterized by an abrupt break-down of the Northern Hemisphere winter polar vortex, a major stratospheric sudden warming (SSW) can elicit notable and unexpected changes in the mesosphere, as underlined by recent evidence of an elevated stratopause at 80 km. The connection between the stratosphere and mesosphere is potentially tied to gravity waves (GWs) and planetary waves (PWs), dynamical features on the opposite ends of the spatiotemporal spectrum. Given this background, this project seeks to illuminate the stratosphere-mesosphere coupling with respect to major SSWs by (1) characterizing the sources/properties of GWs and PWs in the stratosphere and mesosphere, and by (2) assessing their roles and interactions in driving this coupling and the elevated stratopause. It will employ a three pronged, multiple-scaled approach, based on the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM), the University of Oklahoma's Advanced Regional Prediction System (ARPS), and observations. Using WACCM, resolved planetary-scale and parameterized GW forcings will be examined along with the wave-induced circulation that enhances tracer transport into the stratosphere and influences surface climate. With high spatial resolution, the ARPS simulations will explicitly resolve much of the GW activities up to the lower mesosphere. Through ARPS, the elucidated GW properties will help clarify their sources and forcings seen in WACCM. Finally, satellite observations and analysis products (with inferred and parameterized GW influence) will be examined and compared to model results. The broader impacts of this work are multifold. In the past decade, examinations of major SSWs have focused predominantly on their potential impacts on the troposphere. By broadening the current views to include the mesosphere and details of GWs, new insights on SSW evolution can be obtained through this project. Additionally, related project activities aim to enrich undergraduate education inside and outside the classroom. Participating undergraduates will conduct experiments, analyze model and observational data, and present research results. Finally, the project offers undergraduate research training and exposure to cutting-edge geophysical research that (1) may not otherwise be available at similar state-supported Liberal Arts institutions and that (2) is unique in South Carolina and the greater Southeastern Region.