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X-ray Beam Induced Current Measurements for Multi-Modal X-ray Microscopy of Solar Cells
Published on: August 20, 2019
Evidence for wave heating in the solar corona
1Columbia Astrophysics Laboratory, Columbia University, New York, New York 10027, USA. mhahn@astro.columbia.edu
Annals of the New York Academy of Sciences
|May 17, 2013
Summary
Coronal heating remains a mystery, but new evidence shows that Alfvén waves, a type of solar wave, do dissipate energy at lower heights, potentially solving the mystery of the Sun's hot corona.
Area of Science:
- Solar Physics
- Astrophysics
- Plasma Physics
Background:
- The Sun's corona is millions of degrees hotter than its surface (photosphere).
- Understanding coronal heating is a major unsolved problem in astrophysics.
- Convective motion below the photosphere is the accepted energy source.
Purpose of the Study:
- To investigate the mechanisms of energy transport from the Sun's photosphere to its corona.
- To determine how mechanical energy is deposited as heat in the corona.
- To evaluate the role of waves, specifically Alfvén waves, in coronal heating.
Main Methods:
- Analysis of observational data related to wave propagation in the solar corona.
- Testing theoretical predictions of wave damping mechanisms.
- Investigating the location and efficiency of energy dissipation for Alfvén waves.
Main Results:
- Unambiguous observational evidence confirms that Alfvén waves damp at lower coronal heights.
- This damping occurs at sufficiently low altitudes to be significant for coronal heating.
- Challenges the previous understanding that Alfvén waves remain undamped in the corona.
Conclusions:
- Wave-driven models, particularly those involving Alfvén waves, are strongly supported by new findings.
- The observed damping of Alfvén waves provides a viable mechanism for coronal heating.
- This research offers a key insight into one of astrophysics' most significant challenges.
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