CEDAR: Characteristics of Front Like Structures in Polar Mesospheric Clouds

该合同授予弗吉尼亚理工学院和大学，将支持对卫星成像数据的研究，重点是极地中间层云的形态。本研究将对该地区的动态特性进行统计评价。中间层是一个将大气从地面耦合到地球空间的区域，充满了动力波结构。利用卫星平台成像极地夏季中间层为控制该区域的动力过程提供了丰富的视觉线索，并有助于形成极地中间层云（PMCs），这些云通常发生在空间边缘（~82-86 km）的高纬度（60°N）夏季中间层。先前对这些图像的研究发现了复杂的空间结构（面纱，带，漩涡，空洞等），这些结构被认为是大气重力波（GWs），湍流或开尔文亥姆霍兹不稳定性的表现。这项由该奖项支持的研究将使用广泛的NASA/AIM数据库（15个季节）的云图，结合一致的背景气象（温度、水蒸气）和模型模拟，对探测到的各种形式进行统计量化。这项研究将集中在pmc中常见的“锋”状结构上，这是一种孤立的波或尖锐的阶梯状边界，将中间层云区和无云区分开。以往对中间层锋面的研究都是个案研究，而本研究旨在对这些独特云形态的特征进行全面的统计研究。这项工作将支持一名女性科学家，从而改善航空学界的性别多样性。这项工作还将支持研究生学习有价值的技能和培训，这将有助于这个人进入多元化的STEM劳动力。虽然中间层的动力学本身是复杂的，但对PMC锋面全球特征的全面统计研究将促进对控制夏季高纬度中间层的大气过程的理解。重力波传播的射线追踪与中间层与对流层耦合的研究相结合，将提供有关夏季潜在的中间层GW源的信息，这将有助于改进包含重力波行为表征的全球气候模式。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

The award to Virginia PolyTechnic Institute and University will support a study of satellite imaging data with emphasis upon polar mesosphere cloud forms. This study would evaluate statistically the dynamical properties of this region. The mesosphere is a region that couples the atmosphere from the ground to geospace and is populated with dynamical wave structures. Imaging the polar summer mesosphere with a satellite platform provides rich visual clues to the dynamic processes that control this region and contribute to the formation of Polar Mesospheric Clouds (PMCs) which typically occur in the high-latitude (60°N) summer mesosphere at the edge of space (~82-86 km). Previous study of these images found complex spatial structures (veils, bands, vortex, voids etc.) that have been taken to be signatures of atmospheric gravity waves (GWs), turbulence, or the manifestation of the Kelvin Helmholtz instability. The study supported by this award would use the extensive NASA/AIM database (15 seasons) of cloud images combined with coincident background meteorology (temperature, water vapor) and model simulations to develop a statistical quantification of the various forms detected. This study would focus on the ‘front’ like structure often seen in PMCs, which is a solitary wave or a sharp step-like boundary that separates a mesospheric cloud and no cloud regions. While previous work on mesospheric fronts have been case studies, this study aims to provide a comprehensive statistical study on the characteristics of these unique cloud forms. This work would support a female scientist thus improving gender diversity in the aeronomy community. This work would also support a graduate student who is expected to learn valuable skills and training that would help the entrance of that person into a diverse STEM workforce.While the dynamics of the mesosphere is inherently complicated, a comprehensive statistical study of the global characteristics of PMC fronts will advance the understanding of the atmospheric processes that control the summer high-latitude mesosphere. A ray-tracing of gravity wave propagation combined with the study of the mesosphere coupling with the troposphere would provide information about potential summer mesospheric GW sources that would help improve global climate models that incorporate a representation of gravity wave behavior.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.