Solar Science and Space Weather with the Murchison Widefield Array

The two key phenomenon involved in Space Weather - magnetic reconnection and particle acceleration at shocks and magnetic reconnection sites - are both yet to be understood in sufficient detail. Due to the nature of the emission mechanisms involved, radio observations, especially at metric wavelengths, are sensitive to the local magnetic fields, carry information about particle acceleration sites and shocks where they are produced, and originate at coronal heights which are hard to probe by most other means. Radio observations are unique in that they have they can be used to study the precursors, the drivers as well as the consequences of Space Weather events. The pre-eruption phase of a coronal mass ejection (CME) is often associated with the type III solar bursts. The CME shock location, motion and morphology can be studied using the type II emission. The gyrosynchrotron emission from the accelerated electrons trapped in the CME plasma allow us to estimate the CME magnetic field, among other parameters. Due to Faraday rotation, the CME plasma leaves an imprint of its magnetic topology on the linearly polarised light from background radio sources. A large number of such observations sampling many lines of sight through the CME as it traverses the vast interplanetary space can, in principle, allow to us estimate the 3D magnetic field configuration of the CME, eventually leading to robust Space Weather prediction. Upon arrival on Earth, the terrestrial impact of the CMEs can also be measured using ionospheric observations.