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Alfvén waves in the lower solar atmosphere
David B Jess1, Mihalis Mathioudakis, Robert Erdélyi
1Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, Belfast, BT7 1NN, Northern Ireland, UK. d.jess@qub.ac.uk
Science (New York, N.Y.)
|March 21, 2009
Summary
Scientists detected Alfvén waves in the Sun's atmosphere, originating from a bright point. These torsional oscillations provide a mechanism for heating the solar corona, a long-standing mystery in solar physics.
Area of Science:
- Solar physics
- Plasma astrophysics
- Stellar atmosphere dynamics
Background:
- The mechanisms driving energy flow and heating in the solar atmosphere remain poorly understood.
- Investigating oscillatory phenomena offers insights into energy transport processes.
Purpose of the Study:
- To detect and characterize oscillatory phenomena in the solar atmosphere.
- To identify the wave modes responsible for energy transport and coronal heating.
Main Methods:
- Wavelet analysis of oscillatory phenomena associated with a large solar bright-point group.
- Measurement of oscillation amplitude, periodicity, and Doppler velocities.
- Analysis of intensity oscillations and transversal displacements to rule out wave modes.
Main Results:
- Detection of oscillations with periods from 126 to 700 seconds and 2.6 km/s amplitude.
- Oscillations are coupled with chromospheric Doppler shifts (average 23 km/s blue shift).
- Identification of torsional Alfvén waves with a +/-22 degree twist and a 180-degree phase shift, indicating global induction.
Conclusions:
- The detected torsional Alfvén waves are a significant energy transport mechanism in the solar atmosphere.
- The energy flux from these waves is sufficient to account for solar coronal heating.
- This finding provides a potential solution to the long-standing problem of coronal heating.
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