HR: 10:35h
AN: SH52C-02 [Abstracts]
TI: Propagating Alfven waves in Coronal Loops Observed by Hinode
AU: * Ofman, L
EM: ofman@waves.gsfc.nasa.gov
AF: Catholic University of America, NASA GSFC
Code 671, Greenbelt, MD 20771, United States
AU: Wang, T
EM: wangtj@helio.gsfc.nasa.gov
AF: Catholic University of America, NASA GSFC
Code 671, Greenbelt, MD 20771, United States
AB:
Observations made with Solar Optical Telescope (SOT) on board the Hinode
satellite reveal that coronal loop with flowing cool chromospheric material
exhibit periodic oscillation. Additional related observations were obtained by
EIS imaging spectrometer. The oscillations are visible for about 3 periods in
multiple strands of the loops in transverse direction to the loop axis,
suggesting that these are Alfvén waves propagating along the strands of the
loop. The period of the oscillations is about 2 minutes and the damping time is
on the order of 1000 seconds. The flow velocity of the cool material and the
phase speed of the waves were determined directly, by comparing frames of the
observed time sequence. The phase speed agrees with the expected speed of
standing waves for the observed loop length and period. We find that MHD model
of the waves in a coronal loop is in good agreement with observations. We also
find that the energy flux in the observed waves appears to be sufficient to
heat the loop to coronal temperatures.
DE: 7507 Chromosphere
DE: 7509 Corona
DE: 7524 Magnetic fields
DE: 7836 MHD waves and instabilities (2149, 2752, 6050)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting