Impulse excitation and damping of slow standing mode oscillations in hot coronal loops

Authors Organisations
Type Conference Proceeding (Non-Journal item)
Original languageEnglish
Title of host publicationSOHO 15 Workshop:
Subtitle of host publicationCoronal Heating
Pages443-447
Number of pages5
Edition575
Publication statusPublished - 2004
EventSOHO 15 Workshop: Coronal Heating - , United Kingdom of Great Britain and Northern Ireland
Duration: 06 Sep 200409 Sep 2004

Publication series

NameEuropean Space Agency, (Special Publication) ESA SP
ISSN (Print)0379-6566

Conference

ConferenceSOHO 15 Workshop: Coronal Heating
CountryUnited Kingdom of Great Britain and Northern Ireland
Period06 Sep 200409 Sep 2004
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Abstract

A new theoretical model for the study of slow standing mode oscillations in hot (T > 6 MK) active region coronal loops is presented. These oscillations are observed by the SUMER spectrometer on board the SoHO satellite. The model contains the transition region and the upper chromosphere which enables us to study the entire process of hot loop oscillations - from the impulsive footpoint excitation phase to the rapid damping phase. It is shown that the oscillations can be excited by an impulsive heat deposition due to, e.g., nonlinear Alfvén wave energy deposition or magnetic reconnection at the chromospheric footpoint. The existence of the standing mode oscillations is determined by the duration of the heat deposition. The oscillations are excited most efficiently when the duration of the heat deposition is proportional to the fundamental period of the loop. The amount of released energy determines the oscillation amplitude. The combined effects of thermal conduction and compressive viscosity on the damping time in hot gravitationally stratified loops are much stronger than the effect of chromospheric leakage. The dynamic response of the transition region to the impulsive energy release is examined.

Keywords

  • Corona, Loop oscillations, Sun