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Subphotospheric Convection

Published online by Cambridge University Press:  03 August 2017

Robert F. Stein  and
Åke Nordlund
Robert F. Stein
Affiliation:
Physics and Astronomy Department, Michigan State University, East Lansing, MI 48824, U.S.A.
Åke Nordlund
Affiliation:
Copenhagen University Obs., Øster Voldgade 3, Dk-1350 Copenhagen K, Denmark

Abstract

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Three-dimensional simulations of solar convection are described. The simulations show that viewing convection as a hierarchy of eddies does not properly represent the large scale topology. A better picture is to view convection as a broad warm upflow with embedded cool, narrow, downdrafts. These downdrafts penetrate many scale heights through the convection zone and carry most of the net convective flux. Near the solar surface there are extremely large fluctuations in the temperature (5000-11000 K), entropy and pressure (factor of four). Radiation temperature does not provide an accurate measure of the gas temperature at a given geometric depth, because the opacity is very temperature sensitive. The emergent intensity in the infrared is smaller and has a smaller contrast than in the visible. However, in terms of radiation temperature the infrared is hotter and has a higher contrast than the visible.

Keywords

convectioninfrared: starsSun: granulationSun: interior
Type
Part 3: Infrared Perspectives on Atmospheric Dynamics
Information
Symposium - International Astronomical Union , Volume 154: Infrared Solar Physics , 1994 , pp. 225 - 237
Copyright
Copyright © Kluwer 1994 

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