CEDAR: Characteristics of Front Like Structures in Polar Mesospheric Clouds

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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.