Fundamental astroplasma physics of the sun and heliosphere: Warwick Centre for Fusion Space and Astrophysics Rolling Grant Application

A quantitative understanding of the fundamental physical processes acting in the Sun's corona and solar wind is essential not only to the physics of the Sun and its connection to the Earth's environment, but it also enhances our knowledge of astrophysical plasma processes in general. For instance, the chromosphere is a natural laboratory for studying the MHD of partially ionised plasmas. Coronal magnetohydrodynamic (MHD) waves are of direct relevance to much of the dynamics such as solar flares and eruptions; coronal waves are capable of transferring energy and mechanical momentum from the convection zone into the corona and heliosphere and are associated with the development of plasma instabilities. The solar wind is accelerated to such an extent that it is in principle an MHD turbulence laboratory so that quantifying its fluctuations has direct implications for our understanding of MHD turbulence. Recently, the solar wind has also been found to be a laboratory for a kinetic range of turbulence on scales below the ion gyrofrequency on which MHD no longer holds. Understanding this kinetic range physics is also highly relevant to our understanding of how the corona is heated. Quantifying and understanding the fluctuating solar wind provides an important input into models for the propagation of cosmic rays in the heliosphere, and for magnetospheric dynamics for which the solar wind is the driver. The physics of warm dense matter is at an extreme boundary of our knowledge of plasma physics relevant to astrophysics. A quantitative understanding of these processes, closely coupled to observations, can be seen as either the means to understanding observed phenomena, such as cosmic rays, and the structure of gas giants, or as using the observed phenomena as a strong drive to understanding new fundamental plasma physics. These ideas, techniques and expertise that underpin this programme are thus of impact beyond plasma astrophysics.