摘要
测量夜间135.6nm大气气辉辐射强度是目前有效的电离层探测方式之一,我国即将在风云三号卫星上搭载仪器,利用该波段夜气辉辐射测量来反演电子总含量(本文所指电子总含量表示卫星高度以下大气柱的电子含量)及峰值电子密度,因此非常有必要开展相关的气辉发光模型及反演研究.在介绍氧原子135.6nm波段夜气辉激发机制基础上,考虑辐射在传输过程中受到大气氧原子的散射及氧气分子的吸收,采用迭代法求解包含多次散射及大气吸收衰减的辐射传输方程,得到该波段的体发射率,最终通过考虑包含辐射传输的路径积分计算得到135.6nm气辉辐射强度值.对结果的分析表明:该气辉模型能较好地描述体发射率随高度的分布特征,计算得到的135.6nm夜气辉辐射强度在不同时空及太阳活动的分布与相应条件下峰值电子密度(NmF2)及电子总含量(TEC)的分布基本一致.相同的时空及太阳活动输入条件下,模式计算的135.6nm夜气辉辐射强度与国外同类模式结果的值平均偏差约为3%.文中最后介绍了通过135.6nm夜气辉的辐射强度探测来反演电离层峰值电子密度NmF2及电子总含量TEC的反演方法.
Measuring the nighttime OI 135.6 nm airglow emissions for the study of ionosphere changes has been used as one of the most common ways to detect ionosphere at present. The sensor of measuring the nighttime OI 135.6 nm airglow emissions for obtaining the total electron content and peak electron density will be on board the FY-3 meteorological satellite of China. Because of few far-ultraviolet airglow radiative research in our country, the associated airglow emitting models and the retrieval algorithm study are imperative. Based on the nighttime OI 135.6 nm airglow excitation mechanism research, considering the radiative scattering of the atmospheric oxygen atoms and absorption of oxygen molecules in the band at the radiative transfer process, theiterative method was used to solve the radiative transfer equation including multiple scattering and the atmospheric absorption attenuation. The volume emissive rates at the band could be obtained. Furthermore the radiative intensity was calculated by the path integral calculation of radiative transfer at 135.6 nm band. Analysis of the results shows that the airglow model could be used to describe the volume emissive rates with height distribution well. The 135.6 nm radiative intensities calculated at different spatial temporal distribution and solar activity conditions have a good consistency with NmF2 and TEC. Under the same conditions of spatial temporal and solar activity input conditions, the radiative intensity calculated by the model was compared with similar foreign model and the mean deviation was 3 %, and further confirms the correctness of the model. This paper finally introduced the retrieval algorithm of NmF2 and TEC by measuring the nighttime OI 135.6 nm airglow emissions.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2014年第11期3679-3687,共9页
Chinese Journal of Geophysics
基金
国家自然科学基金(41005013)项目资助
关键词
夜气辉
电子总含量
峰值电子密度
辐射传输
辐射强度
Night airglow
Total electron content
Peak electron density
Radiative transfer
Radiative intensity
