Structure and Dynamics of the Solar Wind

Abstract

Due to high temperature and very small temperature gradient with height, the solar corona is not in hydrostatic equilibrium but is continuously expanding into the inter-planetary space. The expanding coronal plasma is known as the solar wind and its characteristics are studies by 'insitu' and indirect methods. In this paper, we shall highlight capabilities of indirect measurements carried out by the interplanetary scintillation (IPS) technique. A new method for estimation of the solar wind speed using IPS observations of a single station is described. The advantage of this method which is based on refractive scattering approach over the earlier procedures is discussed. It seems that this method can be satisfactorily used in almost all situations of scattering inthe solar wind. The determination of solar wind speed requires theoretical simulation of the observed spectra in most cases, but some of the observations which happen to satisfy the diffractive scattering limits are easier to deal with the new method.