Long-term trends in geomagnetic daily variation
Macmillan, Susan; Droujinina, A.. 2007 Long-term trends in geomagnetic daily variation. Earth, Planets and Space, 59 (3). 391-395.Before downloading, please read NORA policies.
Long-term changes in the magnetic environment of the Earth are of interest to those studying space weather and climate change, particularly in the upper atmosphere. In this paper we examine long-term changes in daily variation as derived from hourly mean values from 14 geomagnetic observatories around the world. Their time series date back to the beginning of the 20th century. We find that there are similar features in all the records, with peaks in the amplitudes of the daily variation occurring in the 1950s and 1980s, and a small upward trend of 1.3 nT/century corresponding to an increase of over 10%. The extrema coincide with those seen in solar irradiance proxy data, in particular the F10.7 flux density dataset which starts in 1947.
|Programmes:||BGS Programmes > Seismology and Geomagnetism|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||22 Sep 2008 14:06|
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