CEDAR: Global and Seasonal Occurrence and Characteristics of Mesospheric Bores

该奖项是一项实验性的努力，旨在描述地球大气中罕见但强烈的扰动，这些扰动通常是肉眼可见的，是从地平线延伸到地平线的称为气辉的微弱光学发射的大带。这些扰动是被称为中间层孔的大气波。这些波的特点是一个广泛的传播“阶梯状”的增强或耗尽气辉的锋面区域跟随一列波。中间层孔具有很大的亮度振幅（通常为10%），可以通过中间层低热层（MLT）区域传输大量的能量和动量。波动动力学显著影响MLT和高层大气区域的大尺度温度和环流结构。了解波对MLT区域的全部影响对于获得大气过程的完整物理图像是重要的。这项工作将利用八个现有的地基光学成像系统的数据，以及一套共同定位的多诊断仪器和卫星数据，以调查MLT区域中层孔和其他锋面重力波的全球和季节性发生特征。这项工作将：1）进行全球调查和表征这些波和估计的动量通量有助于MLT使用波士顿大学的全天空成像仪网络，和2）利用共定位地面多诊断测量和卫星测量，以补充成像仪数据，以充分表征传播环境和重力波的传播modes.This奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

This award is an experimental effort to characterize rare but strong disturbances in the Earth's atmosphere that are often visible to the naked eye as large bands of faint optical emission called airglow that extend from horizon to horizon. These disturbances are atmospheric waves that are known as mesospheric bores. These waves are characterized by an extensive propagating "step-like" frontal region of enhanced or depleted airglow followed a train of waves. Mesospheric bores exhibit large brightness amplitudes (typically 10%) and can transport large amounts of energy and momentum through the mesosphere-lower-thermosphere (MLT) region. The wave dynamics significantly affects the large-scale temperature and circulation structure of the MLT and higher atmospheric regions. Understanding the full scope of wave effects on the MLT region is important for obtaining a complete physical picture of atmospheric processes. This work will utilize the data from eight existing ground-based optical imaging systems, together with a suite of co-located multi-diagnostic instrumentation and satellite data, to investigate the global and seasonal occurrence characteristics of mesospheric bores and other frontal gravity waves in the MLT region. The effort will:1) conduct a global survey and characterization of these waves and an estimate of the momentum flux contributing to the MLT using the Boston University all-sky imager network, and2) utilize co-located ground-based multi-diagnostic measurements and satellite measurements to supplement the imager data in order to fully characterize both the propagation environment and the gravity wave propagation modes.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.