Open AccessNeutral Air Wind Influences deduced from Solar Cycle Changes in the F2 region Equatorial Anomaly
Author(s) -
Brown G. M.
Publication year - 1973
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1973.tb03417.x
Subject(s) - sunspot , solar maximum , solar minimum , longitude , trough (economics) , atmospheric sciences , geology , solar cycle , latitude , anomaly (physics) , solar cycle 24 , f region , ionization , range (aeronautics) , geodesy , physics , solar wind , ionosphere , geophysics , plasma , ion , magnetic field , materials science , condensed matter physics , quantum mechanics , economics , composite material , macroeconomics
Summary The positions of the F2 equatorial trough and mid‐latitude crests can be determined with considerable precision at longitudes where it is possible to restrict data to a very narrow range of longitude. Detailed changes in the position of the crests at the equinoxes have been studied for sunspot maximum and sunspot minimum conditions, and it is shown how several features can be qualitatively accounted for in terms of the influence of the thermospheric neutral air winds on the F2 ionization. The solar cycle influence arises from the fact that the velocity of such winds is primarily controlled by the ion drag forces, and is therefore considerably greater at sunspot minimum than at sunspot maximum.