基于激光雷达手段的海南地区重力波与其波谱的季节分布特性研究

	基于激光雷达手段的海南地区重力波与其波谱的季节分布特性研究
	邹旭; 杨国韬; 王继红; 龚少华; 程学武; 岳川; 张铁民; 傅军
刊名	地球物理学报
	2015
卷号	58 期号:7 页码:2274-2282
关键词	海南激光雷达重力波季节分布青藏高原地形及对流赤道潜流
ISSN号	0001-5733
其他题名	Gravity wave parameters and their seasonal variations derived from Na lidar observations at Hainan, China
通讯作者	杨国韬,gtyang@spaceweather.ac.cn
中文摘要	利用子午工程海南激光雷达对我国海南地区上空进行持续观测,通过3年的累积观测数据对我国低纬度地区重力波活动的季节分布特性进行研究,依据重力波线性理论对海南地区上空的大气密度扰动规律、空间功率谱及时间频率谱进行分析,并通过选择波长在1 km至8 km范围内具有特定波长以及具有波动周期为60 min至25 min的特定频率的重力波辅助研究大气密度扰动的季节变化规律,总结得出海南地区重力波活动具有夏季大、春秋季小、而冬季依然频繁的季节性分布规律.结合海南地区特殊的地理位置与当地季节性气候特征分析得出海南地区上空重力波活动季节性变化的可能原因为青藏高原地形及我国南海地区存在的热带强对流与赤道潜流共同作用的结果.
英文摘要	Sodium lidar is recognized as a useful tool to investigate gravity wave (GW) which influences the circulation, structure and composition of middle and upper atmosphere notably. For further understanding GW and their characteristics, more sufficient observational data within global models, especially those at low latitude are extremely expected. Meanwhile, long-term observations are also quite helpful for the GW analysis. As one part of Meridian Project, the observational Na lidar system at Hainan (19. 50 degrees N, 109. 1 degrees E) employed the double wavelengths laser beam, which is consists of three channels for Mie scattering, Rayleigh scattering and broadband sodium fluorescence. A pulsed Nd:YAG laser was rebuilt to trigger off two green laser beams simultaneously, one of which was 532 nm and used to excite the Mie and Rayleigh scattering, and the other laser beam pumped by a pulsed dye laser was about 589 nm and with 30 mJ per pulse. Resonant fluorescence from the sodium layer was received by a Cassegrain telescope with a primary mirror of 1000 mm diameter. The lidar profiles are stored automatically in a computer. The temporal and spatial resolution was about 167s and 96 m, respectively. Seasonal variations of the GW activity and their spectra at Hainan were studied with comparison to the previous reports and the predictions of theories of GW saturation and dissipation. The seasonal variations of GW activity and characteristics spectra at Hainan are mainly presented as follows: (1) The mean RMS atmospheric density perturbation over Hainan are 5. 63 %, which at solstice are obviously larger than that near the equinox. And the GW activity in winter is still active, which are quite different from those reports at the middle latitude area. (2) Due to the linear theory, the m spectra were calculated which show power law shapes and their range of variation were between -2. 14 and -3. 56 with an annual mean value of -2. 93. The calculated omega spectra were between -1. 22 and -2. 36 with an annual mean value of -1. 80, respectively. (3) The amplitudes of atmospheric density perturbation spectra at m = 2 pi/8km, 2 pi/4km, 2 pi/2km, 2 pi/1km and omega = 2 pi/60min, 2 pi/40min, 2 pi/25min all exhibit large nightly variability as well as large seasonal variations, with the maxima occurring near the solstice. While in winter, their amplitudes indicated that the GW activity is still active, which are consistent with the RMS atmospheric density perturbation annual variations. (4) The seasonal variation regularity of the GW activity at Hainan and the possible GW source there were discussed. It is concluded that the reaction of the Qinghai-Tibet plateau with the convection and the equatorial undercurrent may be the main reason of the GW behaviors at Hainan. The seasonal variation of GW activity at Hainan were measured based on 3 year's observation. The RMS atmosphere perturbation, the vertical wave number spectral amplitudes at 2 pi/8km 2 pi/4km 2 pi/2km and 2 pi/1km and omega spectra with those frequencies at 2 pi/60min, 2 pi/40min, 2 pi/25min all show that the semiannual maxima occur near the solstices, while the GW activity in winter is still active, which is quite different from the middle latitude area. The vertical wave number spectra and frequency spectra were also calculated which were fitted well with the theoretical value. It is concluded that the fact of the Qinghai-Tibet plateau's topography, intense convection of South China Sea and the equatorial undercurrent could be the main reason of the GW's behaviors at Hainan.
收录类别	SCI ; EI ; CSCD
语种	中文
CSCD记录号	CSCD:5485562
内容类型	期刊论文
源URL	[http://ir.nssc.ac.cn/handle/122/4727]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	邹旭,杨国韬,王继红,等. 基于激光雷达手段的海南地区重力波与其波谱的季节分布特性研究[J]. 地球物理学报,2015,58(7):2274-2282.
APA	邹旭.,杨国韬.,王继红.,龚少华.,程学武.,...&傅军.(2015).基于激光雷达手段的海南地区重力波与其波谱的季节分布特性研究.地球物理学报,58(7),2274-2282.
MLA	邹旭,et al."基于激光雷达手段的海南地区重力波与其波谱的季节分布特性研究".地球物理学报 58.7(2015):2274-2282.