edu.ucar.opensky::articles:42309 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T18:51:52.984960 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.net/ark:/85065/d7jm2fxj https://doi.org/10.25935/temb-ys31 https Related Dataset #1 ORN NDA MEFISTO Sun EDR FITS data collection https://doi.org/10.25935/x1yw-1w68 https Related Dataset #2 ORN NDA NewRoutine Sun EDR FITS data collection Imaging a large coronal loop using type U solar radio burst interferometry 2024-04-01T00:00:00Z publication https://n2t.net/ark:/85065/d7jm2fxj https://doi.org/10.3847/1538-4357/ad26fd Zhang, J. author Reid, H. A. S. author Carley, E. author Lamy, L. author Zucca, P. author Zhang 张, PeiJin 沛锦 author Cecconi, B. author UCAR/NCAR - Library publisher Solar radio U-bursts are generated by electron beams traveling along closed magnetic loops in the solar corona. Low-frequency (&lt;100 MHz) U-bursts serve as powerful diagnostic tools for studying large-sized coronal loops that extend into the middle corona. However, the positive frequency drift component (descending leg) of U-bursts has received less attention in previous studies, as the descending radio flux is weak. In this study, we utilized LOFAR interferometric solar imaging data from a U-burst that has a significant descending leg component, observed between 10 and 90 MHz on 2020 June 5th. By analyzing the radio source centroid positions, we determined the beam velocities and physical parameters of a large coronal magnetic loop that reached just about 1.3 R &#8857; in altitude. At this altitude, we found the plasma temperature to be around 1.1 MK, the plasma pressure around 0.20 mdyn, cm &#8722;2 , and the minimum magnetic field strength around 0.07 G. The similarity in physical properties determined from the image suggests a symmetric loop. The average electron beam velocity on the ascending leg was found to be 0.21 c , while it was 0.14 c on the descending leg. This apparent deceleration is attributed to a decrease in the range of electron energies that resonate with Langmuir waves, likely due to the positive background plasma density gradient along the downward loop leg. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication <style type="text/css"></style><span style="font-family:Arial;font-size:10pt;font-style:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span> None eng geoscientificInformation