CEDAR: Lidar and Radar Investigations of Turbulence in the Arctic Mesosphere and Lower Thermosphere

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The investigators will study wave-breaking, instability, and turbulence in the Arctic middle atmosphere. Specifically, an integrated study that combines lidar, radar, and satellite measurements will be conducted to characterize turbulence in the presence of persistent mesospheric inversion layers. The study will draw on established instruments at Chatanika, Alaska (65°N, 147°W); namely an established Rayleigh lidar and the Poker Flat Incoherent Scatter Radar. The lidar will yield high-resolution temperature and density measurements that allow characterization of the mesospheric inversion layers and wave activity in the mesosphere and lower thermosphere (MLT). The radar will provide spectral measurements of turbulence. These observations will provide a framework for characterizing turbulence in the presence of persistent instabilities in the upper mesosphere and lower thermosphere. The wintertime Arctic middle atmosphere provides a unique natural laboratory for observing large-scale wave breaking and persistent instabilities in the middle atmosphere. In the winter planetary waves, generated in the troposphere, routinely break in the stratosphere and mesosphere and disrupt the circulation. Studies to date indicate that the western Arctic may be a center of action for planetary wave breaking and formation of persistent mesospheric inversion layers due to the presence of the Aleutian anticyclone and the interactions between the anticyclone and the Arctic vortex during periods of enhanced planetary wave activity. The study's focus is on observations of waves and turbulence at the lower border of the Space Atmosphere Interaction Region (SAIR). This SAIR-based study addresses the coupling that is critical to a systems-based understanding of the atmosphere, represents a transition in geospace, and determines the current structure and composition of geospace and how it evolves. The research will fuse knowledge from remote sensing and geophysical fluid analysis, and directly support understanding in natural sciences. It will support education and training of students in science and engineering, employ and extend research infrastructure in the Arctic, enhance international collaborations, and promote collaboration amongst universities and laboratories in the US and Japan. The research results will be integrated into the University of Alaska programs and disseminated through a variety of professional, educational, and outreach programs.