Stereoscopic Measurements of Coronal Doppler Velocities with Solar Orbiter

by Olena Podladchikova, Louise Harra, Krzysztof Barczynski, Cristina Mandrini, and Solar Orbiter Mission Consortium

Hosted by Physikalisch-Meteorologisches Observatorium Davos (PMOD/WRC) on September 10, 2020


The Solar Orbiter mission, whose orbit is outside the Sun-Earth line, opens up novel opportunities for the combined analysis of measurements by solar imagers and spectrometers. For the first time different spectrometers will be located at wide angles with each other allowing 3D spectroscopy in the solar atmosphere. In order to develop a methodology for these opportunities, we make use of the Hinode EUV Imaging Spectrometer (EIS) and Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) and by employing solar rotation we simulate the measurements of two spectrometers that have different views of solar corona. The resulting data allows us to apply stereoscopic tie-pointing and triangulation techniques designed for SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) imaging suite on the STEREO (Solar Terrestrial Relations Observatory) spacecraft pair and perform three-dimensional analysis of Doppler shifts of quasi-stationary active region.

We present a technique that allows the accurate reconstruction of the 3D velocity vector in plasma flows along open and closed magnetic loops. This technique will be applied to the real situation of two spacecraft at different separations with spectrometers onboard. This will include the Solar Orbiter Spectral Imaging of the Coronal Environment (SPICE), the Solar Orbiter Extreme Ultraviolet Imager (EUI), the Interface Region Imaging Spectrograph (IRIS) and Hinode EIS spectrometers and we summarise how these can be coordinated. This 3D spectroscopy is a new research domain that will aid the understanding of the complex flows that take place throughout the solar atmosphere.