HR: 0800h
AN: SH22A-0844    [Abstracts]
TI: Intensity and Velocity Structure of a Light Bridge in a Pore Seen by IBIS at NSO/DST: Analysis and Interpretation
AU: * Berrilli, F
EM: berrilli@roma2.infn.it
AF: Dipartimento di Fisica, Universita' di Roma Tor Vergata, V.le Ricerca Scientifica,1, Rome, I- 00133, Italy
AU: Giordano, S
EM: giordano@roma2.infn.it
AF: Dipartimento di Fisica, Universita' di Roma Tor Vergata, V.le Ricerca Scientifica,1, Rome, I- 00133, Italy
AU: Del Moro, D
EM: delmoro@roma2.infn.it
AF: Dipartimento di Fisica, Universita' di Roma Tor Vergata, V.le Ricerca Scientifica,1, Rome, I- 00133, Italy
AU: Penza, V
EM: penza@roma2.infn.it
AF: Dipartimento di Fisica, Universita' di Roma Tor Vergata, V.le Ricerca Scientifica,1, Rome, I- 00133, Italy
AB: Light bridges are bright structures separating umbral areas of pores or sunspots in two or more sub-regions. We analyze intensity and velocity small scale properties of a light bridge, observed in the pore AR10812, using both broad-band and monochromatic images acquired with the Interferometric BI-dimensional Spectrometer (IBIS) at the adaptive optics channel of the NSO/Dunn Solar Telescope. The observed pore shows a mean downward velocity of about -200 m/s and an external annulus with average downward velocity of -350 m/s. Besides, an elongated dark structure along light bridge axis matches a feeble upward plasma structure of about +100 m/s. We interpret this sort of reversed convective feature as a consequence of the higher gas pressure in a photospheric field-free cusp, above the light bridge, located between two magnetic walls. To reproduce this configuration, we developed a simple light bridge thermal model in which we consider a quiet field free region below a partially emptied of plasma magnetic region.
UR: http://www.fisica.uniroma2.it/~solare/index.htm
DE: 7524 Magnetic fields
DE: 7529 Photosphere
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting