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Solar Physics: From the Deep Interior to the Hot Corona

  • Dermott J. Mullan
Conference paper
Part of the Lecture Notes in Physics book series (LNP, volume 556)

Abstract

We present an overview of the thermal properties of the Sun from the hot interior to the hot corona. For pedagogical reasons, we confine the discussion to certain relevant solutions of the energy conservation equation. In the interior, quantitative information can be obtained by using a polytropic equation of state: internal temperatures obtained in this way are found to be reliable to about 10%, and we can obtain a good estimate of the depth of the convection zone. In the chromosphere, acoustic waves originating in the convection zone do work on the gas: as the gas heats up, the atomic energy levels of many elements (especially hydrogen) exert a strong thermostatic control so that the temperature is confined to a steady value in the range 5000-104 K. In long-lived coronal loops, a steady state balance between thermal conduction and radiative losses causes the temperature of the electrons to lie in the range (1-2) million K. Coronal ions are heated to greater temperatures than electrons. In flares, processes of heating and cooling are explicitly non-steady, and short-lived excursions to temperatures as high as 25 million K (or more) are observed in the largest flares.

Keywords

Solar Wind Coronal Hole Solar Corona Solar Atmosphere Convection Zone 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Dermott J. Mullan
    • 1
  1. 1.Bartol Research InstituteUniversity of DelawareNewarkUSA

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