Speaker
Description
First Name: Arpit Kumar
Last Name: Shrivastav
Affiliation: Southwest Research Institute, Boulder, Colorado
All Authors: Rohan Bose, Momchil Molnar, Joseph Plowman, Lakshmi Pradeep Chitta, Vaibhav Pant, Donald Hassler, Tania Varesano, Ritesh Patel, Daniel B. Seaton, Marelina Mierla, Andrei N. Zhukov, David Berghmans
Abstract: Large-scale coronal structures, such as streamers and pseudostreamers, are believed to be potential sources of the slow solar wind, contributing to its structured nature and variability. However, the physical mechanisms that release plasma from these structures into the solar wind are still not well understood. In this study, we investigate a pseudostreamer observed off-limb with the Full Sun Imager (FSI), while its footpoints were simultaneously captured by the High Resolution Imager (HRIEUV) and the Spectral Imaging of the Coronal Environment (SPICE). HRIEUV data reveal the presence of propagating disturbances (PDs) near the pseudostreamer boundary, extending up to heights of 50–60 Mm along several open strands. These PDs exhibit projected velocities between 27 and 250 km/s and show quasi-periodic behavior with an average period of approximately 11 minutes. SPICE Doppler velocity maps and abundance diagnostics indicate persistent blueshifts and coronal composition near the pseudostreamer base. We assess whether the observed blueshifts are associated with upflows or downflows using 3D reconstruction from CROBAR. Additionally, the FSI imaging sequence shows signatures of downflows arising from interactions between magnetic field structures near the pseudostreamer cusp. These results highlight the complex dynamics occurring within pseudostreamers and indicate that the inner- and middle coronal processes in these structures can facilitate plasma transport into the outer corona, thereby contributing to the generation of the solar wind.