Andes上空中间层和低热层中大气惯性重力波的激光雷达观测  

Lidar Observation of Atmospheric Inertial Gravity Waves in the Mesosphere and Lower Thermosphere in the Sky of Andes

作　　者：胡飞 黄开明[1] LIU Alan 杨遵勋 HU Fei;HUANG Kai-ming;YANG Zun-xun(School of Electronic Information, Wuhan University, Wuhan 430072, China;College of Arts and Sciences, Embry-Riddle Aeronautical University , Daytona Beach, Florida 86301, America)

机构地区：[1]武汉大学电子信息学院,武汉430072 [2]安柏瑞德航空大学文理学院,佛罗里达州,代托纳海滩86301

出　　处：《科学技术与工程》2019年第14期29-38,共10页Science Technology and Engineering

基　　金：国家自然科学基金(41474127,41674151)资助

摘　　要：利用Andes观测站(30. 3°S,70. 7°W)激光雷达2016年6月8~9日共11. 6 h的风场、温度以及钠原子数密度的观测数据,研究了一个在中间层顶区域惯性重力波活动事件。谱分析表明,这个惯性重力波的周期约6. 6 h,垂直波长约7. 5 km,水平波长约826 km。根据矢端曲线法分析发现,此惯性重力波的传播方向大约为西偏北38. 6°。计算出它的垂直群速度约0. 2 m·s-1,水平群速度约22. 9 m·s-1。射线追踪结果表明,上传惯性重力波可能来自于平流层的急流区域。虽然该惯性重力波不能达到不稳定性的阈值,但是理查德森数和浮力频率显示,由于不同扰动分量的叠加,导致了在一些高度和时间上,动力学的发生和对流不稳定性的存在。因此,叠加效应引起的不稳定性可能会对中间层-低热层中波的饱和度和幅度约束有显著影响。同时利用重力波偏振关系和惯性重力波纬向风扰动,计算出了经向风、温度和大气密度扰动,同时观测的经向风和温度扰动与计算的结果一致,表明观测到的准单色惯性重力波能很好满足重力波偏振关系。另外,计算得到的大气密度扰动与观测的钠原子数密度扰动相位一致,证实了中间层-低热层区域的钠原子可以作为重力波的示踪物。By using the 11. 6 h wind field,temperature and sodium atomic density observed data from the Na lidar system at Andes Lidar Observatory( 30. 3°S,70. 7°W) from 2212 UT 8 June to 1024 UT 9 June in 2016,a typical upward propagating inertial-gravity wave( IGW) in the mesosphere and lower thermosphere( MLT) was studied. The spectral analysis reveales that the period of the IGW was about 6. 6 h,vertical wavelengths is abut 7. 5 km and horizontal wavelengths was about 826 km. Hodograph technique showed that the IGW propagates in the horizontal direction about 38. 6° west of north and its horizontal group and vertical group velocities were 22. 9 m·s-1 and 0. 2 m·s-1 by calculated. The ray-tracing analysis indicated that the upward propagating IGW probably originates from the stratospheric unbalances flow over the Antarctic. Although the IGW could not reach the threshold of instability,Richardson number and buoyancy frequency display that the superposition of different disturbance components lead to the generation of dynamics and the existence of convective instability at some heights and times.Hence,the instability arising from the superposition effect might have a significant influence on wave saturation and amplitude constraint in the MLT. According the IGW polarization relations,the perturbation components of the meridional wind,temperature and atmospheric density were derived from the zonal wind perturbation. The meridional component,temperature and atmospheric density disturbance wene calculated by using the polarization relation of gravity wave and the zonal component disturbance of inertial gravity wave. At the same time,the observed and calculated values of meridional wind and temperature disturbance were consistent. The results show that the observed quasi-monochromatic inertial gravity wave can satisfy the polarization relation of gravity wave well. In addition,the phase of the calculated atmospheric density disturbance is consistent with that of the observed atomic number density disturbance confirmed tha

关 键 词：激光雷达观测 惯性重力波 矢端曲线法 偏振关系 射线追踪 

分 类 号：P353[天文地球—空间物理学]