Radar Studies of the Polar Summer Mesosphere

在极高纬度地区的雷达观测显示，在极地夏季中间层中存在一个增强的后向散射区域。大气层的这个区域是地球上最冷的地方，也是地球上最高的云：北极夜光云的观测地点。在之前nsf资助的一项研究中，该提案的PI提出了一个理论，即增强的雷达回波是带电的气溶胶，这些粒子像雪一样缓慢向下漂移。虽然不被接受，但PI将继续通过更详细地研究带电气溶胶模型解释雷达观测的方式来调查这一想法。此外，该项目还将专门研究北极夜光云与极地夏季中间层中增强的雷达回波之间的关系。

Radar observations at very high latitudes have revealed the existence of a region of enhanced backscatter in the polar summer mesosphere. This region of the atmosphere is the coldest place on earth and is the location at which the highest clouds on earth are observed: arctic noctilucent clouds. In a previous NSF-funded study, the PI of this proposal has put forth the theory that the enhanced radar echoes are charged aerosols and that these particles are drifting slowly downward analogous to snow. Although not accepted, the PI will continue to investigate this idea by studying in more detail the manner in which the charged aerosol model can account for the radar observations. Furthermore, the PI will address specifically the question of the association between arctic noctilucent clouds and these enhanced radar echoes in the polar summer mesosphere.