中高层O_(2)A带夜气辉时空分布特征

Spatial and Temporal Distribution of O_(2) A-Band Night Airglow in Mesosphere and Lower Thermosphere

气辉是中高层大气的重要光化学现象,其中O_(2)A带(762 nm)气辉是进行中高层温度探测的最佳观测目标之一。基于Optical Spectrograph and InfraRed Imaging System(OSIRIS)在2008年间探测的O_(2)A带夜气辉辐亮度数据,研究了该气辉全球性时空分布特征。对于夜气辉辐亮度在不同纬度带内的海拔-季度分布,研究结果表明,O_(2)A带夜气辉辐亮度的高值存在于海拔95 km附近,同时南北半球A带夜气辉辐亮度随季节的变化特征刚好相反,北半球辐亮度高值出现在第二、三季度,而南半球辐亮度高值出现在第一、四季度。另外,对于夜气辉辐亮度在不同季度的纬度-经度分布,发现O_(2)A带夜气辉在经向分布较均匀,而纬向分布波动较大。辐亮度高值所在的纬度区间在不同季度具有差异性。研究结果与相关文献相似,证明了本结果的正确性。同时,从气辉季度变化规律和影响因素的角度分析,推断夜气辉的分布具有周年往复的趋势。O_(2)A带夜气辉的时空分布特征对后续仪器设计的研究有重要意义。

Airglow is an important photochemical phenomenon in the mesosphere and lower thermosphere region(MLT region),and O_(2)A-band(762 nm)airglow is one of the best observation targets for temperature detection in the MLT region.The radiance data of O_(2)A-band night airglow observed by the Optical Spectrograph and InfraRed Imaging System(OSIRIS)in 2008 were used to study the global spatial and temporal distribution of the night airglow.For the altitude-quarter distribution of night airglow radiance in different latitudes,the results indicated that the highest radiance of O_(2)A-band night airglow existed near the altitude of 95 km.In contrast,the seasonal variations of O_(2)A-band night airglow in the Northern Hemisphere and the Southern Hemisphere were opposite.To be specific,the highest radiance appeared in the second and third quarters in the Northern Hemisphere but in the first and fourth quarters in the Southern Hemisphere.The latitude-longitude distribution of night airglow radiance in different quarters shows that the longitudinal distribution of O_(2)A-band night airglow is relatively uniform,while the latitudinal distribution fluctuates widely.The latitude region of the highest radiance varies in different quarters.The above results are consistent with those in the relevant literature,which prove the correctness of our results.Furthermore,the analysis of the seasonal variation law of airglow and its influencing factors reveals that the distribution of night airglow has an annual reciprocating trend.The spatial and temporal distributions of O_(2)A-band night airglow are of great significance for further research on instrument design.