Volume 486, Number 3, August II 2008
|Page(s)||1003 - 1007|
|Published online||29 May 2008|
Cycle dependence of the longitudinal-latitudinal sunspot motion correlations
Heliophysical Observatory of the Hungarian Academy of Sciences 4010 Debrecen PO Box 30, Hungary e-mail: firstname.lastname@example.org; email@example.com
Accepted: 10 April 2008
Aims. It is well known that the azimuthal and meridional shifts of sunspots are correlated and that the correlation exhibits a latitudinal distribution, which is expected due to the Coriolis effect. We study the temporal behaviour of this latitudinal distribution.
Methods. We analyze the daily positions of sunspot groups, provided by the Debrecen Photoheliographic Data and the Greenwich Photoheliographic Results and correlation values, which were mapped in latitudinal bins. The latitudinal distributions were examined for each year.
Results. We derive a sunspot-motion correlation that exhibits a Coriolis-type latitudinal distribution on long timescales, which are typical for the yearly distributions; at cycle maximum, however, unexpected distortions can occur.
Conclusions. The causes of the weakening of the Coriolis-pattern remain unclear. Possible relations of the phenomenon to the Gnevyshev-gap, the polarity reversal of the main magnetic field, and some mid-period fluctuations are discussed.
Key words: Sun: activity / Sun: rotation / sunspots
© ESO, 2008
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.