Determination of Coronal Magnetic fields from Type II Band Splitting and Density Measurement

Details Determination of Coronal Magnetic fields from Type II Band Splitting and Density Measurement Determination of Coronal Magnetic fields from Type II Band Splitting and Density Measurement

Jun 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006spd....37.0904c&link_type=abstract

American Astronomical Society, SPD meeting #37, #9.04; Bulletin of the American Astronomical Society, Vol. 38, p.236

Astronomy and Astrophysics

Astronomy

Scientific paper

We have derived the magnetic field and Alfven speed in the low corona (1.5-2.0 solar radii) from the observations of type II band-splitting and coronal WL polarization during the 2004 August 18 CME. The data used are the radio spectrum obtained with Green Bank Solar Radio Burst Spectrometer (GBSRBS) and the coronal polarization brightness measured with MK 4 coronameter of Mauna Loa Solar Observatory (MLSO). We estimated a density jump and the Alfven Mach number from the splitting frequency ratio of the burst under the assumption that the band splitting is due to plasma radiation from upstream and downstream of the coronal shock, respectively. The estimated Alfvenic Mach number is 1.4-1.5, nearly constant during the propagation. We also determined the coronal background density by inversion of the coronal polarization data and used the density and type II frequency to determine the shock speed. While the density is determined over a wide area, we select the density along the streamer under the assumption that the type II burst is generated at the interface of the CME flank and streamer interaction. Alfven speed is then derived from the shock speed and the Alfven Mach number, which lies in range from 540 to 440 km/s. Finally, the magnetic field strength is derived from the Alfven speed and density along the path of the shock: 1.3 G-2.0 G (1.5-2.0 solar radii). The Alfven speed and the magnetic field derived in this study are comparable to those calculated from the active coronal magnetic field model by Dulk and McLean and the one-fold Newkirk coronal density model.

Affiliated with

Also associated with

No associations

Rating

Determination of Coronal Magnetic fields from Type II Band Splitting and Density Measurement does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Determination of Coronal Magnetic fields from Type II Band Splitting and Density Measurement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Determination of Coronal Magnetic fields from Type II Band Splitting and Density Measurement will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1328659