Speaker
Description
First Name: Yingjie
Last Name: Zhu
Affiliation: ETH Zürich
All Authors: Yingjie Zhu, Tom Schad, Louise Harra, Sage Constantinou, Krzysztof Barczynski, Sarah Jaeggli, Enrico Landi, Judit Szente, Ioannis Kontogiannis, Adriana De-Sassi
Abstract: Active regions (ARs), in particular the quasi-open, fan-like loops at their boundaries, are suggested as one of the potential source regions of slow solar wind during solar maximum. Recent in situ measurements from Solar Orbiter and Parker Solar Probe indicate that the solar wind undergoes continuous acceleration in interplanetary space through the dissipation of Alfvén wave energy. In this study, we quantify the Alfvén wave energy flux in closed and quasi-open loop systems within an AR observed by the National Science Foundation’s Daniel K. Inouye Solar Telescope (DKIST). The state-of-the-art spectropolarimetric observations of the Fe XIII 1074 and 1079 nm lines obtained with the Cryogenic Near Infrared Spectropolarimeter (Cryo-NIRSP) enable direct measurements of the line-of-sight (LOS) magnetic field, electron density, and non-thermal line broadening, which are key parameters for deriving the Alfvén wave energy flux. Using triangulation between FSI 174 and AIA 171 observations, we estimate orientations of quasi-open field lines relative to the POS and apply geometric corrections to the Alfvén wave energy flux inferred from the LOS magnetic field. Our results provide essential constraints on models of coronal heating and solar wind acceleration.