University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Tuesday, November 19th 2019
1:25 pm:
Space Physics Seminar in Tate 201-20
Speaker: Cynthia Cattell and Lindsay Glesener
Subject: Periodicities in Type III radio bursts observed by Parker Solar Probe and in coronal active regions

Periodicities have frequently been reported across many wavelengths in the solar corona. We focus on coordinated observations of Type III radio busts from the Fields instrument on Parker Solar Probe, of EUV emissions in the 211A and 171A bands by the SDO/AIA, and of solar flare x-rays by Nuclear Spectroscopic Telescope Array (NuSTAR) on April 12, 2019. Periodicities of ~ 5 minutes in the EUV in several areas of an active region are well correlated with the repetition rate of the Type III radio bursts. Detrended 211A light curves show periodic sawtooth profiles in one area, with rapid drops occurring slightly after the onset of the radio bursts. In this area, the detrended light curves for the 171A band show similar periodicity, with peaks lagging those seen in 211A. This is suggestive of rapid and impulsive cooling. NuSTAR x-rays provide evidence for a flare during the interval of Type III bursts but there is not a one to one correspondence between the x-rays and Type III bursts. Observations are somewhat consistent with previous studies showing correlated periodicities in 211A and Type II bursts, although periods are longer. Five minute periods have frequently been reported in sunspots

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.