HR: 16:35h
AN: SH24A-05    [Abstracts]
TI: Modeling of the Radio Metric Emission of the Quiet Sun Corona Using Potential Field Source Surface Extrapolations
AU: * Marque, C
EM: christophe.marque@nrl.navy.mil
AF: Universities Space Research Association, Naval Research Laboratory 4555 Overlook Av SW, Washington, DC 20375 United States
AU: Wang, Y
EM: ywang@pinoak.nrl.navy.mil
AF: Naval Research Laboratory, 4555 Overlook Av SW, Washington, DC 20375 United States
AU: Thernisien, A F
EM: arnaud.thernisien@nrl.navy.mil
AF: Universities Space Research Association, Naval Research Laboratory 4555 Overlook Av SW, Washington, DC 20375 United States
AU: Howard, R A
EM: russ.howard@nrl.navy.mil
AF: Naval Research Laboratory, 4555 Overlook Av SW, Washington, DC 20375 United States
AU: Vourlidas, A
EM: angelos.vourlidas@nrl.navy.mil
AF: Naval Research Laboratory, 4555 Overlook Av SW, Washington, DC 20375 United States
AB: We present the result of a modeling of the Quiet Sun corona in the metric radio range (F~150-450 MHz). At these frequencies, the radio emission is dominated by non-thermal emissions (plasma emissions) due to populations of accelerated electrons, and, when the solar activity is low or moderate, by the thermal emission of the corona (bremsstrahlung). While this emission mechanism is well known, depending only on the electron density and temperature, the difficulties arise from the refraction that affects the radio waves propagating in the corona, which depends on the electron density distribution. In order to build a realistic description of the electron and temperature distribution in the corona for a given date, we have used Potential Field Source Surface extrapolations, based on synoptic maps of the photospheric magnetic field. The density and temperature distribution is based on scaling laws which depend on the field strength as well as the length of the loops. We use radio data from the Nancay Radioheliograph to constraint the free parameters of these scaling laws, and make qualitative and quantitative comparisons between the radio images and the simulations.
DE: 7509 Corona
DE: 7524 Magnetic fields
DE: 7534 Radio emissions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly