HR: 1330h
AN: SP43B-05    [Abstracts]
TI: Quasi periodicities in the Fluctuations of the Axisymmetric Solar Magnetic Field from Independent Component Analysis
AU: * McDonald, D P
EM: daniel.mcdonald@csun.edu
AF: California State University, Northridge, Department of Physics, CSUN , Northridge, CA 91330 United States
AU: Cadavid, A C
EM: ana.cadavid@csun.edu
AF: California State University, Northridge, Department of Physics, CSUN , Northridge, CA 91330 United States
AU: Lawrence, J K
EM: john.lawrence@csun.edu
AF: California State University, Northridge, Department of Physics, CSUN , Northridge, CA 91330 United States
AU: Ruzmaikin, A
EM: aruzmaik@mail1.jpl.nasa.gov
AF: Jet Propulsion Laboratory, Jet Propulsion Laboratory California Institute of Technology, Pasadena, CA 91109 United States
AB: Observed solar, interplanetary and geomagnetic time series contain quasi periodicities on the order of 1 to 2.5 years. The further discovery of 1.3 year fluctuations in helioseismic observations suggests that a variety of signals may be related to the underlying dynamo in the Sun. We have applied the methods of principal component analysis (PCA) and independent component analysis (ICA) to search for the coherent structures (PCA) and independent global modes (ICA) of the axisymmetric solar magnetic field. While PCA was shown to be effective in identifying the coherent modes that describe the 22 yr solar cycle, ICA uncovers the independent global modes with characteristic 1 to 2.5 yr quasi periods observed in heliospheric and helioseismic time series. We found that five modes effectively describe the data in both spatial and temporal domains. Two modes describe the polar and high latitude fields, and present 1-1.5 year quasi periodicities. The other three modes correspond to low and mid-latitude phenomena and show both 1.3 year and 1.7 year variations. By comparing the characteristic timescales, dates of occurrence and heliocentric latitudes of these modes, we connect them to their manifestations in heliospheric time series.
DE: 7524 Magnetic fields
DE: 7529 Photosphere
SC: Solar Physics Division - AAS [SP]
MN: 2005 Joint Assembly