Effects of solar cycle variations on oxygen green line emission rate over Kiso, Japan

• Published in: Earth, planets, and space Vol. 63; no. 8; pp. 941 - 948
• Main Authors: Das, Uma, Pan, C. J., Sinha, H. S. S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.01.2011; Terra; Springer Nature B.V
• Subjects: Cosmochemistry. Extraterrestrial geology; Earth; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Emission; Emission analysis; Exact sciences and technology; Flux; Geology; Geophysics/Geodesy; Photometers; Quasi-biennial oscillation; Solar activity; Solar cycles; Far East; Asia; Japan; Hilbert-Huang Transform; Mesosphere; solar cycle effects; airglow; Very low frequency; Nightglow; wavelet transformation; Airglow; amplitude; correlation; Solar radio flux; solar activity; solar cycles; Quasi biennial oscillation; oxygen; Green line
• ISSN: 1343-8832; 1880-5981
• DOI: 10.5047/eps.2011.04.006

A sixteen year long dataset of mesospheric OI 557.7 nm green line nightglow emission rate, measured over Kiso (35.79°N, 137.63°E), Japan using ground-based photometers is spectrally investigated using the Hilbert-Huang Transform (HHT). The spectrograms reveal the presence of semi-annual, annual and quasi-biennial oscillations in consonance with the results obtained from wavelet analysis in an earlier study. In addition, due to the use of the HHT, we have been able to investigate the very low frequency solar cycle variation in the emission rate. It is found that there is a significant solar cycle effect on the oxygen green line emission rate. The mean amplitude of variation is approximately 20% and it is also found that it is maximum at midnight. A correlation study between the means of the emission rate and the solar radio flux at 10.7 cm also shows that the effect of solar activity on the oxygen green line emission rate is maximum at midnight.