HR: 1340h
AN: SH53B-0315    [Abstracts]
TI: The asymmetry in sunspot area and magnetic flux variations in 1996-2004 extracted from the Solar Feature Catalogues
AU: Zharkov, S I
EM: s.zharkov@brad.ac.uk
AF: Bradford University, Cybernetics Department , Bradford, BD7 1DP United Kingdom
AU: * Zharkova, V V
EM: v.v.zharkova@brad.ac.uk
AF: Bradford University, Cybernetics Department , Bradford, BD7 1DP United Kingdom
AB: This research utilizes a searchable Solar Feature Catalogue (SFC) for sunspots created from the SOHO/MDI full disk whitelight images and magnetograms in 1996-2004 using the automated pattern recognition techniques {\bf $http://www.cyber.brad.ac.uk/egso/$}. A comparison of sunspot areas from the SFC with the averaged sunspot numbers published in the Sunspot Index Data Centre (SIDC) verified the detected sunspots with their correlation with sunspots areas on agiven day that revealed a very good detection accuracy of $86%$ for the whole period 1996-2003. The latitudinal (N-S) and longitudinal variations of sunspot areas, a total and resulting, or excess, magnetic flux are presented for the whole period of observations. The total sunspot areas measured from a single solar image have shown to have a strong Northern-Southern asymmetry that reveals the similar trend in the cumulative sunspot areas. At the start of the cycle from 1996 until 1999 the Northern hemisphere area trails the Southern one then followed by a bigger increase of the areas in the Northern hemisphere. The excess magnetic flux confined in sunspots also shows a significant N-S asymmetry being mostly negative in the Southern hemisphere and positive in the Northern one. However, towards the solar minimum in 1996 and in 2003-4 the excess flux becomes positive in the Southern and negative in the Northern hemispheres. These variations of total and excess magnetic fluxes during the solar cycle are compared with a few solar dynamo models.
DE: 7514 Energetic particles (2114)
DE: 7524 Magnetic fields
DE: 7538 Solar irradiance
DE: 2479 Solar radiation and cosmic ray effects
DE: 1650 Solar variability
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting