MODELING SUPER-FAST MAGNETOSONIC WAVES OBSERVED BY SDO IN ACTIVE REGION FUNNELS

Journal Article · Thu Oct 20 00:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/740/2/L33· OSTI ID:21565382

Ofman, L ^[1]; Liu, W; Title, A; Aschwanden, M ^[2]

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1. Department of Physics, Catholic University of America, Washington, DC 20064 (United States)
2. Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States)

Recently, quasi-periodic, rapidly propagating waves have been observed in extreme ultraviolet by the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) instrument in about 10 flare/coronal mass ejection (CME) events thus far. A typical example is the 2010 August 1 C3.2 flare/CME event that exhibited arc-shaped wave trains propagating in an active region (AR) magnetic funnel with {approx}5% intensity variations at speeds in the range of 1000-2000 km s{sup -1}. The fast temporal cadence and high sensitivity of AIA enabled the detection of these waves. We identify them as fast magnetosonic waves driven quasi-periodically at the base of the flaring region and develop a three-dimensional MHD model of the event. For the initial state we utilize the dipole magnetic field to model the AR and include gravitationally stratified density at coronal temperature. At the coronal base of the AR, we excite the fast magnetosonic wave by periodic velocity pulsations in the photospheric plane confined to a funnel of magnetic field lines. The excited fast magnetosonic waves have similar amplitude, wavelength, and propagation speeds as the observed wave trains. Based on the simulation results, we discuss the possible excitation mechanism of the waves, their dynamical properties, and the use of the observations for coronal MHD seismology.

• OSTI ID: 21565382
• Journal Information: Astrophysical Journal Letters, Vol. 740, Issue 2; Other Information: DOI: 10.1088/2041-8205/740/2/L33; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
EXTREME ULTRAVIOLET RADIATION
MAGNETIC FIELDS
MAGNETOACOUSTIC WAVES
MAGNETOHYDRODYNAMICS
MASS
PULSATIONS
SIMULATION
SOLAR CORONA
SOLAR FLARES
THREE-DIMENSIONAL CALCULATIONS
ATMOSPHERES
ELECTROMAGNETIC RADIATION
FLUID MECHANICS
HYDRODYNAMICS
HYDROMAGNETIC WAVES
MECHANICS
RADIATIONS
SOLAR ACTIVITY
SOLAR ATMOSPHERE
STELLAR ACTIVITY
STELLAR ATMOSPHERES
STELLAR CORONAE
STELLAR FLARES
ULTRAVIOLET RADIATION