Open AccessType II solar radio bursts: Modeling and extraction of shock parameters
Author(s) -
Hillan D. S.,
Cairns I. H.,
Robinson P. A.
Publication year - 2012
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2011ja016754
Subject(s) - shock (circulatory) , spectral line , shock wave , physics , computational physics , algorithm , meteorology , computer science , mechanics , astronomy , medicine
This first paper in a two part series summarizes the current theory and the data‐driven solar wind model for simulating dynamic spectra of type II radio bursts. It also introduces performance metrics and techniques for extraction of model shock parameters from these dynamic spectra. We use an iterative downhill simplex method which compares two dynamic spectra and quantitatively assesses and improves the agreement using two figures of merit: the first is based on the correlation function and the second is based on a normalized differences over the data set. By maximizing the agreement we are able to extract the input model shock parameters to within 30% or better when using model solar winds of increasing complexity. The effects on the spectra predicted and on the figures of merit from changing the model shock parameters and solar wind model are also investigated. The iterative downhill extraction method is then applied to the type II dynamic spectrum predicted using a realistic model solar wind and a shock model estimated for an observed type II event. The shock parameters are recovered to within 10% of the correct solution.