摘要
瑞利多普勒激光雷达可对平流层和中间层大气的水平风速和温度进行连续观测。中国科学技术大学最新研制的瑞利测风测温激光雷达增加了多普勒频率校准装置,可实现对晴空天气下15~70 km大气的水平风速和温度的高精度观测。分析了该激光雷达系统2018年9~10月在我国西北部地区的水平风速和温度连续观测数据,通过提取风速和温度扰动、频谱分析、重力波模型参数拟合及Hodograph分析,计算重力波的垂直波长、固有周期、水平和垂直传播方向等参数。从224 h的观测数据中共计提取到重力波384个波次。在这些重力波事件中,53.9%的垂直传播方向为向上。风速和温度的波动幅度分别集中在10~20 m/s和10~20 K,70%以上的垂直波长在5~10 km范围内,极少出现15 km以上的波动;水平波长在100~200 km左右,固有周期<5 h的波动占比较大,水平传播方向以西偏北20°和东偏南20°的相向的方向为主导。
Rayleigh Doppler Lidar was often used for horizontal wind speed and temperature observation in stratosphere and middle atmosphere.University of Science and Technology of China introduced a Doppler frequency calibration device in the newly developed Lidar system,which can achieve high-precision observation of the horizontal wind speed and temperature of 15-70 km of the atmosphere under clear sky.The continuous observation data of the horizontal wind speed and temperature of the Lidar system was analyzed in the northwest area of China from September to October,2018.The gravity wave parameters,such as the vertical wavelength,natural period,horizontal and vertical propagation directions,were reached by extracting wind speed and temperature disturbance,spectrum analysis,gravity wave model parameter fitting and Hodograph.A total of 384 gravity waves were extracted from 224 h of observation data.In these waves,53.9%of the vertical propagation direction is upward.Fluctuation amplitude of wind speed and temperature is concentrated at 10-20 m/s and 10-20 K.More than 70%of the vertical wavelength is in a range of 5-10 km,and fluctuations of more than 15 km rarely occurred.The horizontal wavelength is centered at 100 km to 200 km,and the dominant intrinsic period is less than 5 h.The horizontal propagation direction is dominated by the opposing directions of 20°west-northwest and 20°east-south.The distribution characteristics of gravity waves are consistent with the local dominant wind direction and the distribution of surrounding mountains.
作者
张楠楠
赵若灿
孙东松
韩淤利
陈冲
Zhang Nannan;Zhao Ruocan;Sun Dongsong;Han Yuli;Chen Chong(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China)
出处
《红外与激光工程》
EI
CSCD
北大核心
2020年第S02期191-196,共6页
Infrared and Laser Engineering
基金
国家自然科学基金(41904136)
