北京上空中层顶区域重力波参数关系的激光雷达研究

基于子午工程项目北京钠激光雷达的长期观测数据(2010年4月到2011年9月), 采用Yang等人(2008)的重力波参数提取方法,提取了在253个夜晚2 208 h的有效观测时间里出现的162个钠层单色重力波的垂直波长、周期、幅度值和幅度增长因子参数值.统计分析显示激光雷达所观测到的中层顶区域重力波具有系统性的参数关系,z=0.226Tob0.530、KE=6.6610-10 kz-3.091和KE=8.9710-6 fob-1.696.这些实验观测结果验证了Gardner(1994)扩散滤波理论的结果,但同时发现仅认为波致涡流扩散是重力波衰减的主要途径是不完全正确的,其它因素引起的衰减在重力波的饱和和耗散机制中也起到了重要作用.

Lidar study on the parameter relations of gravity waves in the mesopause region at Beijing

Based on the long-term observations from Beijing sodium lidar of Chinese Meridian Project, 162 monochromatic gravity waves was distinguished in the sodium layer during the 2208 hours' observation in 253 nights(from 2010 April to 2011 September). The vertical wavelength, wave period, wave amplitude and its growth factor of every monochromatic gravity wave were precisely extracted with the method derived by Yang et al.(2008). Statistical results reveal that there are systematic relationships between those wave parameters, and they respectively are z=0.226Tob0.530、KE=6.6610-10 kz-3.091 and KE=8.9710-6 fob-1.696. Those results partially agree well with the results predicted by Gardner's(1994) diffusive filtering theory. However, it is found incorrect to regard the wave-induced eddy diffusivity as the only main damping processes of gravity waves. It is suggested that the damping processes caused by other possible factors also play important roles in the saturation and dissipation mechanisms of gravity waves.