Premium
Geomagnetic activity indicates large amplitude for sunspot cycle 24
Author(s) -
Hathaway David H.,
Wilson Robert M.
Publication year - 2006
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 - 10.1029/2006gl027053
Subject(s) - solar minimum , coronal mass ejection , solar cycle 22 , solar cycle 24 , solar cycle 23 , amplitude , solar maximum , sunspot , earth's magnetic field , solar cycle , physics , atmospheric sciences , solar wind , solar flare , environmental science , astrophysics , magnetic field , optics , quantum mechanics
The level of geomagnetic activity near the time of solar activity minimum has been shown to be a reliable indicator for the amplitude of the following solar activity maximum. The geomagnetic activity index aa can be split into two components: one associated with solar flares, prominence eruptions, and coronal mass ejections which follows the solar activity cycle and a second component associated with recurrent high speed solar wind streams which is out of phase with the solar activity cycle. This second component often peaks before solar activity minimum and has been one of the most reliable indicators for the amplitude of the following maximum. The size of the recent maximum in this second component indicates that solar activity cycle 24 will be much higher than average – similar in size to cycles 21 and 22 with a peak smoothed sunspot number of 160 ± 25.