HR: 1330h
AN: SH13C-03    [Abstracts]
TI: Active Region Oscillations and Their Relation to the Magnetic Field Topology
AU: * Muglach, K
EM: kmuglach@gmx.de
AF: ARTEP Inc., Naval Research Laboratory, 4555 Overlook Ave, Washington, DC United States
AU: Hofmann, A
AF: Astrophysikalisches Institut Potsdam, An der Sternwarte 16, Potsdam, Germany
AU: Staude, J
AF: Astrophysikalisches Institut Potsdam, An der Sternwarte 16, Potsdam, Germany
AB: In this contribution we present an analysis of time sequences of MDI intensity and Doppler velocity together with simultaneous filtergrams taken by TRACE at 1700A in an active region. The high frequency halos found in MDI velocity and the deficiency of high frequency power sampled at the height of the TRACE UV filter around the active region can be explained by an interaction of the acoustic wave field with the magnetic field of the active region. From a magnetic field extrapolation we calculate the plasma β for the complete TRACE FOV up to the base of the corona. The contours giving the location of β approximately 1 where h=500 km agree very well with the decrease in 1700A high frequency power.
DE: 7507 Chromosphere
DE: 7524 Magnetic fields
DE: 7529 Photosphere
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly