Thermal conduction damping of longitudinal waves in coronal loops
Abstract
High cadence TRACE observations show that outward propagating intensity disturbances are a common feature in large coronal loops. An overview is given of measured parameters of such longitudinal waves in coronal loops. We found that loops that are situated above sunspot regions display intensity oscillations with periods centred around 3 minutes, whereas oscillations in `non-sunspot' loops show periods centred around 5 minutes. The observed longitudinal waves are interpreted as propagating slow magneto-acoustic waves and we show that the disturbances are not flare-driven but are most likely caused by an underlying driver exciting the loop footpoints. We found that (slightly enhanced) thermal conduction could account for the observed damping lengths.
- Publication:
-
Publications of the Astronomy Department of the Eotvos Lorand University
- Pub Date:
- February 2003
- Bibcode:
- 2003PADEU..13..127D