Geomagnetic lunar and solar daily variations during the last 100 years

Yamazaki, Yosuke and Kosch, Michael (2014) Geomagnetic lunar and solar daily variations during the last 100 years. Journal of Geophysical Research, 119 (8). pp. 6732-6744. ISSN 0148-0227

[thumbnail of jgra51196]
PDF (jgra51196)
jgra51196.pdf - Published Version
Available under License Creative Commons Attribution.

Download (1MB)


This paper describes long-term changes in the geomagnetic lunar (L) and solar (S) daily variations. We analyze the eastward component of the geomagnetic field observed at eight midlatitude stations during 1903–2012. The amplitude and phase for the semidiurnal component of the L and S variations are examined. Both L and S amplitudes correlate with the solar activity index F10.7, revealing a prominent 11 year solar cycle. In both cases, the correlation is slightly better with inline image than F10.7. The sensitivity of the L variation to solar activity is comparable with that of the S variation. The solar cycle effect is also found in the phase of the S variation but not apparent in the phase of the L variation. The ratio in the amplitude of the L to S variation shows a long-term decrease (approximately 10% per century), which may be due to a reduction in lunar tidal waves from the lower atmosphere to the upper atmosphere in association with climate change.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Geophysical Research
Additional Information:
©2014. The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Uncontrolled Keywords:
?? geomagnetic daily variationsionospheric currentssolar activityupper atmospherelong-term variationsclimate changeearth and planetary sciences (miscellaneous)geophysicsatmospheric sciencespace and planetary science ??
ID Code:
Deposited By:
Deposited On:
11 Aug 2014 23:06
Last Modified:
31 Jan 2024 00:26