Analyzing airglow measurements can yield a lot of information about the MLT region of the atmosphere. Many studies have focused on understanding how airglow responds to CO2 increase and solar cycle variations. This paper examines how CO2 increase, solar cycle variation and geomagnetic activity each influence volume emission rate (VER), VER peak height and airglow intensity. The results from simulated induced variations of O(1S) greenline, O2(0,1) atmospheric band, and OH(8,3) airglow show that the airglow intensities and peak VERs of the three emissions are correlated and in phase with F10.7 solar cycle variations, and the airglow intensities and peak VERs exhibit linear relationships with the CO2 increase (see left side figure). After more evaluation of the results, this study also shows that the VER peak heights are mostly out of phase and exhibit an inverse relationship with the Ap-index (used as a proxy for geomagnetic activity), and the CO2 increase gradually lowers the VER peak heights of OH(8,3) and O(1S) greenline by 0.2km over a 55 year time period but doesn’t change the VER peak height of O2(0,1) atmospheric band. (see right side figure). Overall, the results presented in this paper suggest that airglow in the MLT region is influenced by F10.7 solar cycle variation, CO2 increase, and geomagnetic activity. Similarly, the results also show that CO2 increase has a weaker effect than the F10.7 solar cycle variations and Ap-index.

 

Reference: Huang, T.-Y., Influences of CO2 increase, solar cycle variation, and geomagnetic activity on airglow from 1960 to 2015, Journal of Atmospheric and Solar-Terrestrial Physics (2017), http://dx.doi.org/10.1016/j.jastp.2017.06.008