基于激光雷达、气辉仪和流星雷达对海南岛中高层大气温度结构变化和重力波活动的观测与研究

Based on the long-term observations of atmospheric activities from lidar, airglow imager, and meteor radar, atmospheric temperature structures and gravity wave activities in the middle and upper atmosphere over Hainan (19.5°N, 109.1°E) will be studied in this proposal project. Lidar at Hainan Normal University, airglow imager and meteor radar at Fuke belong to the Chinese Meridian Project. Observations and researches of the middle and upper atmosphere, basing on the three instruments, are partially supported by the Project Supported by the Specialized Research Fund for State Key Laboratories..Hainan lidar is a dual-wavelength lidar (@532nm, @589nm), and the atmospheric temperature structure in the altitude range of 35-85 km can be measured by combining lidar signals from the Rayleigh scattering channel (532 nm) and the sodium resonance fluorescence channel (589 nm). To reveal the seasonal variation characteristics of atmospheric temperature over Hainan Island, lidar-observed results would be firstly contrasted to those from SABER/TIMED satellite and model NRLMSISE-00. And then, lidar-observed phenomena of Mesosphere inversion layer (MIL) will be statistically investigated, and their formation mechanism will be discussed in detail..For the study of AGW activities in this proposal, lidar-observed vertical temperature perturbations will be analyzed in wavelet analysis method. Gravity wave parameters such as vertical wavelength, period and phase velocity will be extracted. Simultaneous observations from airglow imager at Fuke will be analyzed to obtain the horizontal wavelength, phase velocity and propagation direction of AGWs observed in the mesopause region. Background wind information will be measured by meteor radar at Fuke, and the wind perturbations will be used to extract the intrinsic period and propagation directions of AGWs..According to the simultaneous observations from three instruments above, gravity wave propagations from the stratosphere into the upper mesosphere (35-105 km) will be investigated comprehensively, as well the effects of the wave saturation, dissipation and breaking. And the correlations between AGW activities and those lidar-observed abnormal temperature structures will be studied in this proposed project. .Hainan Island is near the equator and mainly controlled by the tropics marine climate. These works in our proposal can enhance the understanding of the atmospheric dynamics and climatology in lower latitude area. And they could be helpful for the clarification of AGW contributions to atmospheric dynamics in the middle and upper atmosphere. They are also helpful to the space weather forecasting and the establishment of global climate parameterization model.

基于子午工程海南师范大学双波长(532nm、589nm)激光雷达、海南富克台站气辉仪和流星雷达对海南上空大气活动的长期观测,本项目拟采用双波长激光雷达数据拼接方法完成中层大气(35-85 km)温度结构反演,开展海南岛中高层大气温度季节变化以及重力波活动的观测研究工作。对照模式以及SABER卫星的观测结果，揭示近赤道、濒海地区中层大气温度季节变化的区域特性，研究海南上空逆温层现象。分析激光雷达对温度垂直结构的探测结果，采用小波方法分析重力波引起的大气温度扰动，提取重力波的垂直参数；利用气辉仪和流星雷达的同时观测，得到重力波在中层顶附近的水平参数以及背景风场信息；研究平流层到中层顶高度范围中的重力波传播过程，以及重力波饱和和耗散对中高层大气的影响，揭示重力波活动与中层大气异常温度结构的相关性；拓宽人们对低纬度大气动力学过程以及气候学的认知，服务于空间天气预报和相关模型的建立。

基于国家重大科技基础设施“子午工程”项目激光雷达、NRLMSISE-00大气模式、SABER卫星和COSMIC卫星的测量数据，完成了Rayleigh激光雷达对中层大气温度探测的高精确反演与矫正技术开发；在此基础上，通过计算大气重力波活动导致的相对温度扰动，采用小波分析提取了重力波活动的特征参数，并完成了重力波扰动的垂直波数谱和时间频率谱的计算，探讨了大气重力波的饱和、破碎和耗散对背景大气的影响。同时，通过分析海南激光雷达在2011-2020年间的长期观测数据，完成了海南中层大气(30-65 km)温度结构的长期变化研究工作。结果表明，海南岛平流层顶位于 42-51 km 高度，中层大气日平均温度最高～262 K；中层大气温度变化呈现出明显不同于中高纬度地区的年、半年、季节变化特征；平流层顶温度的年际变化趋势对辐射通量F10.7指数变化有较明显的响应。另外，基于延庆和平泉激光雷达的2009-2020年间的长期观测数据，首次报道了我国上空中层云事件，并统计分析了这种罕见的云现象的特征，结合SABER卫星的水汽和温度观测结果，探讨了这种现象的可能形成机制，认为这种罕见的中纬度云现象的出现与全球气候变化导致的大气温度、水汽变化有直接关系，可能是全球气候变化的早期预警。除完成Rayleigh激光雷达对中层大气温度探测的高精确反演与数据矫正的关键技术开发外，这些研究成果揭示了近赤道、濒海地区中高层大气温度季节变化的区域特性，以及中层大气温度的长期变化对太阳活动变化的响应特征。重力波活动区域特性以及中层云的出现机制研究，在当前全球气候变暖的背景下，这些研究结果拓宽人们对我国不同纬度的大气动力学过程以及气候学的认知，能较好地服务于空间天气预报的需要和全球气候参数化模型的建立。