Solar Physics Division Meeting 2000, June 19-22
Session 1. Helioseismology, Magnetic Fields, Chromosphere and Transition Region
Display, Chair: C. U. Keller, Monday-Thursday, June 19, 2000, 8:00am-6:00pm, Forum Ballroom

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[1.38] Properties and Time Variability of Solar Activity Structures

K. L. Harvey (SPRC), J. Barentine (NSO/NOAO)

We investigate the properties of active regions and the network based on the results of an image decomposition of the NSO/Kitt Peak magnetograms. Our decomposition technique uses the magnetic flux density, the spatial distribution of magnetic flux, filling factor, and the presence of sunspots to define six structures -- active regions, decaying active regions, sunspots, enhanced network, quiet network, and the quiet atmosphere (supergranular cell interiors). A total of 798 magnetograms were processed, providing 894 measurements of about 450 active regions and their associated sunspots. We will present the results of a study of the characteristics of the six structure classes, their total magnetic flux, area (surface and apparent), mean flux densities, the partitioning of plage and sunspots in active regions, and how these quantities vary with time during a three-year period from 1 January 1996 to 31 December 1998. This interval covers the minimum period between cycles 22 and 23 and the rise of cycle 23 activity.

The author(s) of this abstract have provided an email address for comments about the abstract: Karen Harvey, SPRC, 4720 Calle Desecada, Tucson, AZ 85718;

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