SPICE Connection Mosaics to link the Sun's surface and the heliosphere

TL;DR

This paper analyzes the first connection mosaic from Solar Orbiter's SPICE instrument, linking coronal composition with in-situ solar wind measurements, revealing FIP fractionation and plasma characteristics in active regions.

Contribution

It introduces a novel connection mosaic analysis combining spectral diagnostics and composition measurements to trace the solar wind source regions.

Findings

Isothermal plasma around LogT=5.8 in active regions

Higher FIP-bias at coronal loop footpoints

Solar Orbiter connected to a slow solar wind source

Abstract

We present an analysis of the first connection mosaic made by the SPICE instrument on board of the ESA / NASA Solar Orbiter mission on March 2nd, 2022. The data will be used to map coronal composition that will be compared with in-situ measurements taken by SWA/HIS to establish the coronal origin of the solar wind plasma observed at Solar Orbiter. The SPICE spectral lines were chosen to have varying sensitivity to the First Ionization Potential (FIP) effect, and therefore the radiances of the spectral lines will vary significantly depending on whether the elemental composition is coronal or photospheric. We investigate the link between the behavior of sulfur with the hypothesis that Alfv\'en waves drive FIP fractionation above the chromosphere. We perform temperature diagnostics using line ratios and Emission Measure (EM) loci, and compute relative FIP biases using three different approaches (two line ratio (2LR), ratios of linear combinations of spectral lines (LCR), and differential emission measure (DEM) inversion) to perform composition diagnostics in the corona. We then compare the SPICE composition analysis and EUI data of the potential solar wind source regions to the SWA / HIS data products. Radiance maps are extracted from SPICE spectral data cubes, with values matching previous observations. We find isothermal plasma of around LogT = 5.8 for the active region loops targeted, and that higher FIP-bias values are present at the footpoints of the coronal loops associated with two active regions. Comparing the results with the SWA/HIS data products encourages us to think that Solar Orbiter was connected to a source of slow solar wind during this observation campaign. We demonstrate FIP fractionation in observations of the upper chromosphere and transition region, emphasized by the behavior of the intermediate-FIP element sulfur.