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

[2.42] The dynamic nature of the supergranular network

A. M. Title, C. J. Schrijver (SLISR), A. A. van Ballegooijen (CfA), H. J. Hagenaar (R.U.Utrecht), R. A. Shine (SLISR)

The magnetic field in the quiet solar photosphere evolves as flux concentrations fragment in response to sheared flows, merge when they collide with others of equal polarity, or (partially) cancel against concentrations of opposite polarity. Newly emerging flux, mostly in ephemeral regions, replaces the canceled flux in a matter of a few days. We present a quantitative statistical model to describe the resulting histogram of fluxes contained in concentrations of magnetic flux in the quiet network. We discuss this dynamic flux balance with respect to (i) the potential dispersal of flux in the photosphere as a function of ephemeral-region properties, (ii) sustaining the network--like pattern and mixed--polarity character of the network, and (iii) the formation of unipolar areas covering the polar caps. We establish that ephemeral regions are not the result of the re-emergence of previously cancelled network flux. Moreover, their emergence cannot be correlated to the emergence of active regions but must instead be relatively homogeneous. We also point out that the bulk of the quiet, mixed-polarity network is generated locally, and that only any relatively small polarity excess is the result of flux dispersal from active regions.

Program listing for Friday