基于钠激光雷达观测数据的中间层顶大气温度分布特性研究

Studies for Mesopause Temperature Distribution Characteristics Based on the Sodium Lidar Data

作为中间层和热层的边界层,中间层顶存在多种能量交换方式,是大气能量耦合的重要区域。本文利用部署于中国科学院廊坊临近空间大气探测站的钠荧光多普勒激光雷达2013年的观测数据,研究了廊坊上空中间层顶区域大气温度的年度和季节分布特性,并分析了影响温度分布的多种因素。年平均温度廓线图显示,中间层顶位于约97.5 km高度处,温度约191.2 K。受放热化学反应的影响,年平均温度廓线91 km高度处出现了一个198 K的相对温度高点。中间层顶区域大气温度的季节分布受太阳辐射和大气动力学因素综合影响,夏季在大气动力学影响下,中间层顶高度较低,位于88 km高度处,温度也较低,约177 K;冬季太阳辐射起主导作用,中间层顶位于99 km高度处,温度为181 K。通过拟合月平均温度分析了中间层顶区域大气温度年变化和半年变化的振幅和相位特征。结果显示,中间层顶区域上部温度分布主要受太阳辐射的影响;在中间层顶区域下部,大气波动主导了温度分布。

As the boundary of mesosphere and thermosphere,mesopause is an important area for studying the middle and upper atmosphere,many energy coupling processes happen here,study for the temperature distribution characters will improve our understanding of the climatology of this region.This paper studies the annual and seasonal temperature distribution characteristics based on the Langfang sodium lidar data in 2013.Results show that,the annual mean mesopause locates at around 97.5 km with the temperature 191.2 K.Under the influence of exothermic chemical reactions,there is a relative maximum temperature 198 K at 91 km on the annual profile.The seasonal temperature at mesopause region is influenced by solar radiation and atmospheric dynamics.In winter,solar radiation is the primary factor,producing a higher mesopause of 181 K at 99 km altitude.In summer,the rising atmosphere from lower altitude makes a colder mesopause at 88 km altitude with the temperature 177 K.Harmonic analysis demonstrates a strong change in annual amplitudes over a rather small altitude range,coupling with the annual phase profile,and it is shown that dynamics in lower mesopause region and solar radiation in upper mesopause region play the key role in determining the thermal structure respectively.