2010年海口上空突发钠层事件观测

使用钠荧光激光雷达观测2010年低纬度地区海口(20.0°N, 110.3°E)上空突发钠层事件. 2010年总计观测时间为458h, 观测到突发钠层事件38次, 即每观测12h有1次突发钠层事件发生. 结合武汉上空突发钠层数据, 对比巴西低纬度地区数据, 揭示低纬度地区突发钠层频发现象. 观测到2010年12月30日突发钠层峰值时刻钠层密度廓线具有很好的空间对称性. 分析了距海口激光雷达西南约160km中国海南澹州(19.5°N, 109.1°E)的测高仪数据, 检测了13对突发钠层和电离层偶发事件, 结果表明突发钠层与Es有很强的相关性. 通过 分析低纬度地区上空突发钠层峰值径迹平均速度发现, 大多数突发钠层峰值向 下运动. 

Observation of Sporadic Sodium Layer over Haikou of China in 2010

Sodium lidar observations of Sporadic Sodium Layers (SSL) in 2010 at a low-latitude location (Haikou, China, 20.0°N, 110.3°E) are reported in this paper. The wavelength of the dye laser is set to 589nm by a sodium fluorescence cell. The energy and divergence of the beam are about 45mJ and 1mrad, respectively. The repetition rate of Nd:YAG laser is 30Hz. The backscattered fluorescence photons from the sodium layer are collected by a telescope with a 1000mm diameter primary mirror. From 38 SSLs events detected in about 458h of observation, an SSL occurrence rate of 1 event every 12h at our location was obtained. This result, combined with previous studies at a mid-latitude location (Wuhan, China, 31°N, 114°E), and compared with the SSLs at a low-latitude location (Brazil, 23°S, 46°W), reveals that the SSL occurrence can be frequent at a low-latitude location of Haikou, China. The profiles of a peak density of the SSL were very spatial symmetry on Dec. 30, 2010. With respect to the correlation with sporadic E, the ionosphere data obtained by an ionosonde operated at Danzhou, China (19.5°N, 109.1°E), about 160km southwest of Haikou lidar station, have been examined. By statistical analysis of 13 events, when simultaneous SSL data and ionograms are available, a considerable correlation was found between sporadic E layers and the SSLs. The sporadic sodium layers have average downward vertical velocities at Haikou, China.