Group Introduction

The Solar Wind Group at the University of Wales, Aberystwyth is a newly established group in the Department of Physics and forms an important part of the research activity of the Department of Physics, graded 4 in the last two UK Research Assessment Exercise.  The members of the group (Prof. Shadia Habbal, Dr. Xing Li, Dr. Lorraine Allen) previously were affiliated with Harvard-Smithsonian Center for Astrophysics and joined the group in the past few years.

 The solar physics and solar wind group at Aberystwyth is involved in complementing theoretical investigations of the acceleration of the solar wind with observations of the inner corona. Remote sensing coronal observations from coronagraphs, eclipses and SOHO, together with interplanetary measurements in and out of the ecliptic, are used to map the source regions of the fast and slow solar wind.  Plasma parameters can be determined from coronal spectral line measurements. Coronal spectral lines are produced by ions in the extended corona which resonantly scatter the radiation from the solar disk, or by electron collisional excitation. From spectral line observations, ion temperatures, outflow velocities and wave activities can be derived.  Our unique approach is to use  solar wind models developed in this group to compare with these observations. Some very important information, which is not immediately available from data, can be obtained. For instance, we used this technique to discover that that oxygen ions are already much faster than protons at three solar radii.

 Theoretical investigations of coronal expansion and solar wind acceleration involve understanding the behavior of the plasma during the transition from the Coulomb collision-dominated region to the collisionless region. In recent years, the group has taken a leading role in the development of multi-fluid hydrodynamic solar wind models. Ion cyclotron waves have been studied in these models to explore their interaction with plasma species in the solar wind. These waves have been found to be able to strongly shape the temperature anisotropy of the solar wind ions. Both 1D fluid models and 2D global MHD models have been developed in this group to study the complex nature of the coronal heating and solar wind acceleration processes.