中间层与低热层二氧化碳体积混合比的年际变化特征研究  

Interannual variations of carbon dioxide volume mixing ratio in the mesosphere and lower thermosphere

作　　者：刘栋 董雁冰[1] 毛宏霞[1] 包醒东 魏合理 LIU Dong;DONG YanBing;MAO HongXia;BAO XingDong;WEI HeLi(Science and Technology on Optical Radiation Laboratory,Beijing Institute of Environmental Feature,Beijing 100854,China;Key Laboratory of Atmospheric Optical Radiation,Anhui Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Hefei 230031,China)

机构地区：[1]北京环境特性研究所光学辐射重点实验室,北京100854 [2]中国科学院安徽光学精密机械研究所中国科学院大气光学重点实验室,合肥230031

出　　处：《地球物理学报》2021年第2期429-440,共12页Chinese Journal of Geophysics

基　　金：光学辐射重点实验室基金项目(JCKYS2019204012);国家自然科学基金项目(41505023)资助.

摘　　要：利用17年的SABER(Sounding of the Atmosphere using Broadband Emission Radiometry)Level2C数据研究了中间层与低热层大气(MLT, Mesosphere and Lower Thermosphere) CO2 VMR(Volume Mixing Ratio)的年际变化特征.使用多元线性回归模型对双月平均时间序列拟合,定量地提取各变化特征.结果表明,SABER CO2 VMR长期趋势在中间层保持在5.5%/decade左右,在中间层顶和低热层降低至4.5%/decade左右;结果与模式预测在统计意义上相符.长期趋势没有显著的纬度差异,但在各纬度上都具有明显的季节依赖,MLT CO2 VMR长期趋势的季节性改变源自低层大气长期趋势季节性改变.SABER CO2 VMR对QBO (Quasi-Biannual Oscillation)和ENSO (El Nino-Southern Oscillation)在绝大多数区域没有统计显著的响应;对太阳活动11年循环以负响应为主,在部分区域出现的微弱正响应目前没有合适的物理机制解释.Employing 17-year SABER(Sounding of the Atmosphere using Broadband Emission Radiometry) Level2 C data, the interannual variations of CO2 VMR(Volume Mixing Ratio) in the MLT(Mesosphere and Lower Thermosphere) have been investigated. The multiple linear regression fitting was applied to the bimonthly time series for each latitude bin between 50°S and 50°N from 65 km to 110 km. The results show that the long-term trend of SABER CO2 VMR is about 5.5%/decade in the mesosphere and decreases to about 4.5%/decade in the mesopause and lower thermosphere, which is statistically consistent with the prediction of the model. The noticeable variation of the latitudinal long-term trend has not been found. On the other hand, the seasonal dependence of the trend is visible at all latitudes, which is attributed to the upward propagation of the seasonal dependence of CO2 VMR trend at lower atmosphere. The response to QBO(Quasi-Biannual Oscillation) and ENSO(El Nino-Southern Oscillation) of SABER CO2 VMR is statistically negligible. The response to 11-year solar cycle is negative in the most regions above 80 km owing to the MLT CO2 photolysis and eddy mixing. However, small but statistically significant positive response to solar cycle is present between 65 km and 75 km and at 105 km near equator, which has no appropriate physical mechanism to explain yet.

关 键 词：中间层与低热层 二氧化碳 年际变化 

分 类 号：P351[天文地球—空间物理学]