Shrivastav, Arpit Kumar ; Bose, Rohan ; Molnar, Momchil ; Plowman, Joseph ; Chitta, Lakshmi Pradeep ; Pant, Vaibhav ; Hassler, Don ; Seaton, Daniel B ; Patel, Ritesh ; Mierla, Marelina ; Zhukov, Andrei ; Berghmans, David

Poster presented at AGU Annual Meeting, New Orleans LA on 2025-12-19

Abstract: Large-scale coronal structures, such as streamers and pseudostreamers, are potential sources of the slow solar wind, contributing to its structured nature and variability. However, the mechanisms driving solar wind generation within these structures remain poorly understood. In this study, we analyzed a pseudostreamer observed on the limb using the Full Sun Imager (FSI), with its footpoints captured by the High Resolution Imager (HRIEUV) and Spectroscopic Imaging of the Coronal Environment (SPICE). HRIEUV observations show the presence of propagating disturbances (PDs) near the footpoints, extending to heights of 50–60 Mm in several open strands of the pseudostreamer. The projected velocities of these PDs ranged from 27 to 250 km/s, with an average of 121±48 km/s. The PDs are periodic with an average of ~ 11 minutes in these open magnetic strands. SPICE provides Doppler velocity maps in these regions, indicating the presence of blueshifts near the pseudostreamer base. Additionally, the FSI imaging sequence indicates signatures of downflows arising from interactions between open and closed magnetic field structures within the pseudostreamer. The dynamics within the pseudostreamer and the presence of PDs at the base shed light on the origin of the solar wind in large-scale structures. The identified PDs could contribute to plasma transport into the outer corona, guided by the magnetic topology of the pseudostreamer, and provide mass flux to the solar wind.

Keyword(s): Solar Orbiter ; EUI ; psuedostreamer ; middle corona
Note: SH51E-1211
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