Coronal heating events in high-cadence TRACE data

Citation
J. Ireland et al., Coronal heating events in high-cadence TRACE data, SOLAR PHYS, 190(1-2), 1999, pp. 207-232
Citations number
27
Categorie Soggetti
Space Sciences
Journal title
SOLAR PHYSICS
ISSN journal
00380938 → ACNP
Volume
190
Issue
1-2
Year of publication
1999
Pages
207 - 232
Database
ISI
SICI code
0038-0938(199912)190:1-2<207:CHEIHT>2.0.ZU;2-4
Abstract
On March 23rd 1999 a set of TRACE (Transition Region and Coronal Explorer) observations were taken in support of Solar and Heliospheric Observatory (S OHO)/TRACE Joint Observing Program 83. The program is designed to look for coronal heating mechanisms operating at high cadence and to observe their d ynamical effects on coronal loop density, temperature and magnetic structur e. We present here a study of 27 small, dynamic brightening events seen in this data. These events are seen in the quiet-Sun areas surrounding the act ive region. The data itself consists of 157 171 Angstrom 512x512 arc sec im ages at 1 arc sec resolution and 9 second cadence, a previously unavailable combination of cadence, resolution and image size. Three classes of events are introduced: complex, intermediate and simple. All three classes share the property of being dynamic on small time and length scales but differ in the complexity of their behavior. We find that the brightenings across all classes exhibit variations as part of a distribution of time scales (90-40 0 s) peaked around 228 s. The brightenings are no more than 5 arc sec in di ameter. Motions between brightenings occur on time scales from 9 to 90 s an d on length scales no greater than 10 arc sec. These motions have velocitie s estimated to be in the range 89-174 km s(-1). The position of these event s in the spectrum of previously observed coronal heating events is discusse d.