HR: 1340h
AN: SH13A-1142    [Abstracts]
TI: Photospheric Oscillations in the Solar Atmosphere: Driving Chromospheric Spicules and Coronal Waves
AU: * De Pontieu, B
EM: bdp@lmsal.com
AF: Lockheed Martin Solar & Astrophysics Lab, 3251 Hanover St., Org. ADBS, B. 252, San Francisco, CA 94304 United States
AU: Erdelyi, R
EM: R.von.Fay-Siebenburgen@sheffield.ac.uk
AF: Space and Atmosphere Research Center Dept. of Applied Math University of Sheffield, Hounsfield Road Hicks Building, Sheffield, S3 7RH UK United Kingdom
AU: De Moortel, I
EM: ineke@mcs.st-and.ac.uk
AF: School of Mathematics and Statistics University of St. Andrews, North Haugh, St. Andrews, KY16 9ss United Kingdom
AU: Metcalf, T
EM: metcalf@lmsal.com
AF: Lockheed Martin Solar & Astrophysics Lab, 3251 Hanover St., Org. ADBS, B. 252, San Francisco, CA 94304 United States
AB: There are now many observations of oscillations and waves with periods around 5 minutes in the solar transition region and corona. We provide an observational overview of 5 minute periodicity in upper transition region moss, the low legs of coronal loops, and chromospheric spicules in active region plage. The source of the 5 minute periodicity is unclear, since photospheric p-modes are evanescent in the upper photosphere which should prevent them from propagating into the chromosphere, transition region and corona. Using a numerical model we show that photospheric oscillations can propagate into the low atmosphere as long as they are guided along a magnetic flux tube that is inclined away from the vertical. The leaked photospheric oscillations develop non-linearly into shocks at low chromospheric heights because of the density decrease with height. The upward traveling shocks and resulting rebound shocks of the chromosphere lead to periodic upward chromospheric flows, which in a recent paper we have identified as the periodic spicules that we observe in active region plage. After passage through the spicule, these shocked photospheric oscillations propagate into the corona. We suggest that TRACE observations of propagating acoustic waves in the corona are shocked and tunneled photospheric oscillations. We also explore whether these coronal waves can be exploited to determine the connectivity between photosphere and corona, and thus perform seismology of the lower solar atmosphere.
DE: 7507 Chromosphere
DE: 7509 Corona
DE: 7524 Magnetic fields
DE: 7529 Photosphere
DE: 7546 Transition region
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting