Correlations on Arcsecond Scales Between Chromospheric and Transition Region Structures in Active Regions
Abstract
The discovery of active region moss, i.e, dynamic and bright upper transition region emission at chromospheric heights above active region (AR) plage, provides a powerful diagnostic to probe the structure, dynamics, energetics and coupling of the magnetized solar chromosphere and transition region (TR). Here we present an observational study of the interaction of the chromosphere with the TR moss, by studying correlations (or lack thereof) between emission at varying temperatures: from the low chromosphere (Ca II K-line), to the middle and upper chromosphere (wings of Hα), to the low transition region (C IV 1550 Å~at 0.1 MK), and the upper transition region (Fe IX/X 171 Å~at 1 MK and Fe XII 195 Å~at 1.5 MK). We use several datasets at high cadence (24 to 42 seconds) obtained with the Swedish Vacuum Solar Telescope (SVST, La Palma) and the Transition Region and Coronal Explorer (TRACE). This correlation analysis from low chromosphere to upper TR in AR plage quantifies and considerably expands on previous studies. Our results elucidate various issues, such as: 1. how the heating mechanisms of the chromosphere and lower and upper transition region are related (if at all), 2. how important heating of spicular jets is for the energy balance of the lower TR, 3. the occurrence of significant periodic activity at all levels of the transition region and its coherence over a wide range of temperatures, 4. which time scales dominate the dynamic behavior of the AR transition region, and, 5. whether the spatial and temporal variability of moss can be used as a diagnostic for coronal heating.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFMSH52A0439D
- Keywords:
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- 7507 Chromosphere;
- 7509 Corona;
- 7524 Magnetic fields;
- 7546 Transition region;
- 7549 Ultraviolet emissions