Previous abstract Next abstract

Session 2 - Everything Else.
Display session, Friday, June 27
Ballroom C, Chair: Richard Canfield

[2.47] Scale Dependence of Photospheric Magnetic, Velocity and Temperature Structure

J. K. Lawrence (CSUN), A. C. Cadavid (CSUN), A. A. Ruzmaikin (JPL)

Time series fluctuations may show different structure when observed at different time scale resolutions. Thus, wavelet analysis reveals that fluctuations in the International Sunspot Number are intermittent (that is, distributed with kurtosis K>0) on scales less than 2 yr, but truncated (K<0) on time scales between 2-8 yr. Terrestrial temperature fluctuations are normally distributed (K=0) over discrete timescale bands (<1 yr, 4-6 yr, 13 yr) interspersed by regimes of intermittence (1-4 yr) and truncation (6-13 yr).\par Similar effects occur for spatial phenomena. We employ various continuous, two-dimensional wavelets to analyze digital solar images in Cartesian projection (simultaneous, co-registered San Fernando Observatory magnetic, Doppler and continuum images; SOHO/MDI high resolution Doppler images) and full-disk images in hemispheric projection (KPNO magnetograms, SOHO/MDI Doppler images).\par The temperature and velocity data are normally distributed at all scales up to 64 arc sec, though the temperature gradients are slightly intermittent (K\approx1). The magnetic data are mostly intermittent. Wavelet power spectra for KPNO full-disk magnetograms are quite featureless and indicate scale invariance of the magnetic structures. Structural spectra of both active and quiet sun images, however, show a strong peak in intermittence at a scale near 8 arc sec. Wavelet analysis permits localization of structures in space as well as in spatial scale. The highly intermittent structures can be mapped and are found to be located not in active regions but in some, though not all, areas of low magnetic activity.\par We discuss possible physical relationships among the magnetic, velocity and temperature distributions studied.

The author(s) of this abstract have provided an email address for comments about the abstract:

Program listing for Friday