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Role of centennial geomagnetic changes in local atmospheric ionization
Author(s) -
Usoskin I. G.,
Korte M.,
Kovaltsov G. A.
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl033040
Subject(s) - earth's magnetic field , cosmic ray , atmospheric sciences , latitude , ionization , environmental science , troposphere , ionosphere , geomagnetic latitude , centennial , physics , climatology , geology , geophysics , astrophysics , astronomy , geography , magnetic field , ion , archaeology , quantum mechanics
Many studies of solar‐terrestrial relation are based on globally (or hemispherically) averaged quantities, including the average cosmic ray flux. However, regional effects of cosmic ray induced ionization due to geomagnetic changes may be comparable to or even dominate over the solar signal at mid‐latitudes on centennial‐to‐millennial time scales. We show that local changes of the tropospheric ionization due to fast migration of the geomagnetic axis are crucial on centennial time scale, and the use of global averages may smear an important effect. We conclude that changes of the regional tropospheric ionization at mid‐latitudes are defined by both geomagnetic changes and solar activity, and none of the two processes can be neglected. This substantiates a necessity for a careful analysis of the regional, not global, indices at mid‐latitudes and offers a new possibility to disentangle direct (solar radiation) and indirect (via cosmic rays) effects in the solar‐terrestrial relations.