Combined STELab, EISCAT, ESR, and MERLIN IPS observations of the solar wind

Abstract

The technique of interplanetary scintillation (IPS) can be used to probe interplanetary space between the Sun and Earth most-commonly in terms of speed and also by using the scintillation-level (<i>g</i>-level) as a proxy for density. We combine the large spatial-scale 3D tomographic techniques previously only applied to IPS data from the Solar Terrestrial Environment Laboratory (STELab) array, Nagoya University in Japan, and the previously operational Cambridge IPS system in England, with the finer-scale capabilities of the longer baselines between the systems of the Multi-Element Radio-Linked Interferometer Network (MERLIN) in the UK, and the European Incoherent SCATter (EISCAT) radar and the EISCAT Svalbard Radar (ESR) in northern Scandinavia. Using the UCSD 3D reconstruction technique, we present results of detailed measurements of speed in the solar wind and also those of solar wind flow-directions, constrained by the large-scale density tomography through the use of a kinematic model, as well as applying this tomographic technique for the first time to the MERLIN, EISCAT, and ESR IPS solar wind speed observations in terms of velocity.