Imaging the global solar wind flow in EUV

Abstract

[1] We advance the original concept of imaging the three-dimensional solar wind flow (Gruntman, 2001a) by characterizing expected heliospheric EUV signatures under assumptions of a realistic solar wind. Charge exchange collisions between the solar wind alpha particles and heliospheric atomic hydrogen produce unique emissions in the 30.4-nm line. All-sky images at 30.4 nm with high spectral resolution reveal the three-dimensional flow properties of the solar wind, including the flow in the regions over the Sun's poles, and the variability of the global solar wind properties during the 11-year solar cycle. We simulate global heliospheric images at 30.4 nm for a realistic three-dimensional solar wind with the Sun's effective magnetic dipole tilted with respect to the spin axis, resulting in a complex flow pattern of the plasma. We show that the physical properties of the flow would permit averaging over several rotations of the Sun, thus realistically limiting the total number of all-sky images to a few per year. This feature effectively establishes the sensitivity requirements for an experiment to image the global solar wind.