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Updated: Apr 14, 2026
10:29
Experimental Methodology for Estimation of Local Heat Fluxes and Burning Rates in Steady Laminar Boundary Layer Diffusion Flames
Published on: June 1, 2016
12.5K
Modelling nanoflares in active regions and implications for coronal heating mechanisms
P J Cargill1, H P Warren2, S J Bradshaw3
1Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW, UK School of Mathematics and Statistics, University of St Andrews, St Andrews KY16 9SS, UK p.cargill@imperial.ac.uk.
Summary
New solar observations reveal that solar active regions are heated by frequent, small nanoflare events. These events occur rapidly, suggesting a new model for coronal heating.
Area of Science:
- Solar Physics
- Astrophysics
- Plasma Physics
Background:
- Solar active regions (ARs) are areas of intense magnetic activity on the Sun.
- Understanding the heating mechanisms of ARs is crucial for solar physics.
- Previous models struggled to explain the observed temperatures in ARs.
Purpose of the Study:
- To investigate the heating mechanisms of solar active regions using recent spacecraft data.
- To propose a new model for solar active region heating based on impulsive events.
Main Methods:
- Analysis of observational data from the Hinode and Solar Dynamics Observatory spacecraft.
- Modeling of magnetic field heating processes in the solar corona.
Main Results:
- Solar active regions are heated by numerous small, impulsive events called nanoflares.
- The time between nanoflares in a magnetic strand is estimated to be 500-2000 seconds.
- A weak 'hot' component (above 10^6.6 K) is present, with nanoflare energies as low as 10^23 ergs.
Conclusions:
- The findings support a model of small, rapid heating events in a stressed coronal magnetic field.
- Observed properties are inconsistent with models requiring long energy build-up or steady heating.
- The cooling time between nanoflares is comparable to the time between events on a magnetic strand.
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