中国不同纬度背景Na层夜间和季节变化特征的激光雷达研究  

Lidar studies on the nighttime and seasonal variations of background sodium layer at different latitudes in China

作　　者：龚少华[1,2] 杨国韬[1] 徐寄遥[1] 薛向辉[3] 焦菁[1] 田大伟[1] 傅军[2] 刘正宽[1] 

机构地区：[1]中国科学院国家空间科学中心空间天气国家重点实验室,北京100190 [2]海南师范大学物理与电子工程学院,海口571158 [3]中国科学技术大学地球和空间科学学院,合肥230026

出　　处：《地球物理学报》2013年第8期2511-2521,共11页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41264006;40905012);中国博士后科学基金(20110490609);海南省自然科学基金(413127)资助

摘　　要：基于子午工程的北京、合肥和海南三个Na荧光激光雷达对中国不同纬度上空夜间背景Na层的长期观测,分析了我国沿东经120°N上空Na层的夜间变化和季节变化特征.对照2010年12月17日夜间三个雷达站的观测结果,发现三个地方Na层的夜间变化并不具有相关性.Na层长期变化的年加半年变化拟合结果显示,北京和合肥上空Na层柱密度具有明显的年变化特点,而海南上空Na层柱密度的半年变化特征更明显;Na层的质心高度和RMS宽度具有明显的半年变化特点,但海南地区Na层的RMS宽度的长期变化不具有半年变化特征.Na层参数的统计和对照显示,Na层柱密度的季节变化与大气温度季节变化相关,在冬季最大,在夏季最小.Na层柱密度随纬度升高而增大,同时年变化性逐渐增强;质心高度随纬度变化趋势不明显,但三个地方Na层质心高度的长期变化都具有较明显的半年变化特征;在各个月份中,北京地区Na层RMS宽度最大,合肥地区Na层RMS宽度最小,海南地区居中.Abstract Based on the long-term observation data obtained by Meridian Project sodium lidars at Beijing （40.47°N,115.97°E）, Hefei （31.87°N,117.23°E） and Hainan （19.99°N,110.34°E）, the nighttime and seasonal variations of background sodium layer over China have been investigated along 120°N. Observation results from three lidars on Dec. 17, 2010 show that, the nighttime variations of sodium layer above three different locations do not correlated to each other. The Annual Plus Semiannual Fits to the long-term observation data of sodium layer parameters reveal that the background sodium layer changed with seasons differently at different latitudes. The column abundances of sodium layer over Beijing and Hefei varied annually, and the one over Hainan changed with seasons semiannually. The centroid heights and RMS widths of sodium layer at three locations nearly semiannually varied with seasons. However, the seasonal variation of RMS width of sodium layer observed at Hainan exhibited an annual variation characteristic. Statistics and comparisons on the parameters of sodium layer illustrate that the seasonal variation of sodium density is correlative with the change of temperature of background atmosphere. It has the maximum in summer and minimum in winter, respectively. With the growth of latitude, the sodium density increases and the annual variation characteristic gets more obvious. There is no clear latitude dependence on the centroid height of sodium layer, but all of them observed at three locations changed semiannually with seasons. The RMS width of sodium layer is always biggest at Beijing （middle and upper latitude） and smallest at Hefei （middle latitude） in every month of the year, and it is the medium at Hianan （lower latitude）.

关 键 词：Na激光雷达 Na层夜间和季节变化特征 纬度相关性 

分 类 号：P351[天文地球—空间物理学]