Open AccessComment on “Variations of total solar irradiance produced by structural changes in the solar interior”
Author(s) -
Foukal P.,
Spruit H.
Publication year - 2004
Publication title -
eos, transactions american geophysical union
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.316
H-Index - 86
eISSN - 2324-9250
pISSN - 0096-3941
DOI - 10.1029/2004eo490005
Subject(s) - sunspot , dynamo , solar irradiance , irradiance , convection zone , hydrostatic equilibrium , solar cycle , physics , dynamo theory , atmospheric sciences , variation (astronomy) , convection , solar maximum , astrophysics , meteorology , magnetic field , astronomy , optics , quantum mechanics , solar wind
In a recent Eos article, Sofia [2004] argues for the influence on irradiance variation of global changes in the Sun's structure associated with its magnetic dynamo. These changes would act in addition to the relatively well understood modulation by dark sunspots and bright faculae at the surface. His assessment of the present observational evidence for such a global change agrees with our earlier conclusion that it is not widely convincing at the present time [ Foukal , 2003]. But Sofia's article also claims (1) that the numerical results obtained by him and his collaborators at Yale disagree with and correct earlier work, and (2) that a hydrostatic approximation is not adequate for variations on the 11‐year solar cycle timescale. These surprising claims are based on the results of recently published hydrostatic models [e.g., Sofia and Li , 2004] using the same mixing length approximation for convective heat transport used in earlier work [ Spruit , 1982, 1991; Gilliland , 1988].