CEDAR-TIMED: Colorado State Sodium Lidar Update

研究人员将把科罗拉多州窄带钠激光雷达从用于测量温度和钠密度垂直分布的单光束系统升级为能够同时测量热通量、纬向风和纬向风、纬向动量通量和纬向动量通量的双光束系统。 拟议的升级使激光雷达的功率孔径产品加倍，使具有几种操作几何形状的双光束操作成为可能。 CSU激光雷达现已进入第七个运行年头，并在中层顶区域（80-105公里）提供了独特的观测。 升级后将能够更好地确定平均温度、风和潮汐结构的季节变化，并评价热通量和动量通量的垂直梯度。 中层顶是大气层的一个重要区域，重力波在这里沉积能量和动量，迫使非绝热平均对流流动，据信这是在这些高度观测到的夏季寒冷和冬季温暖温度的原因。这些观测将支持CEDAR/TIMED的科学目标。 CEDAR代表耦合，能量学和大气区域动力学，是一个全球变化计划，将理论建模与地面测量相结合，以研究高层大气和电离层。 TIMED（Thermosphere，Ionosphere，Mesosphere Energetics and Dynamics）是美国国家航空航天局的一个卫星计划，用于研究类似的大气层区域。 CEDAR/TIMED联合方案旨在协调地面和空间观测，以更好地了解低热层和电离层的物理过程。

The investigators will upgrade the Colorado State narrowband sodium lidar from a one-beam system for measuring vertical profiles of temperature and sodium density to a two-beam system capable of simultaneously measuring heat flux, zonal and meridional winds, zonal momentum flux, and meridional momentum flux. The proposed upgrade doubles the power-aperture product of the lidar, making possible a two-beam operation with several operation geometries. The CSU lidar is now in its seventh year of operation and has provided unique observations in the mesopause region (80-105 km). The upgrade will allow better determination of the seasonal variations of mean temperature, winds, and tidal structure, and the evaluation of vertical gradients of heat flux and momentum flux. The mesopause is an important region of the atmosphere where gravity waves, depositing energy and momentum, force a diabatic mean meridional flow that is believed to be responsible for the cold summer and warm winter temperatures observed at those altitudes. These observations will support CEDAR/TIMED science goals. CEDAR, which stands for Coupling, Energetics, and Dynamics of Atmospheric Regions, is a global change program that combines theoretical modeling with ground-based measurements to study the upper atmosphere and ionosphere. TIMED, for Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics, is a NASA satellite program to study similar regions of the atmosphere. The joint CEDAR/TIMED program aims to coordinate ground-based and space-based observations to achieve better understanding of physical processes in the lower thermosphere and ionosphere.