Can granular fluctuations in the solar photosphere produce temperature inhomogeneities at the height of the temperature minimum?

Details Can granular fluctuations in the solar photosphere produce temperature inhomogeneities at the height of the temperature minimum? Can granular fluctuations in the solar photosphere produce temperature inhomogeneities at the height of the temperature minimum?

Mar 1988

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1988a%26a...193..281s&link_type=abstract

Astronomy and Astrophysics (ISSN 0004-6361), vol. 193, no. 1-2, March 1988, p. 281-290.

Astronomy and Astrophysics

Astrophysics

22

Photosphere, Radiative Transfer, Solar Atmosphere, Solar Granulation, Temperature Distribution, Carbon Monoxide, Gas Dynamics, Nonlinear Equations, Surface Temperature, Time Dependence

Scientific paper

We investigate the possibility that the relatively small photospheric temperature fluctuations associated with convective granules may lead to large temperature inhomogeneities at the height of the temperature minimum in stars like the Sun. Our procedure is to construct two-dimensional models of the gas dynamics and radiation transport for the upper convection zone and for the atmosphere up to a height of about 600 km above τross = 1. We include infrared line absorption by the CO molecule and investigate its effect at different effective temperatures. We find that below Teff ≍ 5900 K, molecular cooling produces a steep temperature gradient with an associated convection zone at a height of ≍ 500 km, and a very low surface temperature (Tsurf < 3000 K). For atmospheres with effective temperatures between 5900 K and 6100 K (or hotter), it depends on initial conditions whether a "cool phase" or a "hot phase" upper atmosphere is obtained: both solutions are possible in equilibrium. The calculations always show very homogeneous temperatures in the upper part of the model, roughly corresponding to the location of the temperature minimum. We argue that our failure to find temperature inhomogeneities, although they are suggested by 1-dimensional models, is to be expected because (i) in two and three dimensions horizontal fluctuations of the radiation field decrease rapidly with increasing height above the continuum-forming level, and (ii) the development of significant temperature differences would be counteracted by effective mixing due to horizontal winds. The sort of disparate temperature regions suggested by observations can then only be horizontally separated if they are maintained segregated by magnetic fields or by 3-D circulation.

Affiliated with

Also associated with

No associations

Rating

Can granular fluctuations in the solar photosphere produce temperature inhomogeneities at the height of the temperature minimum? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Can granular fluctuations in the solar photosphere produce temperature inhomogeneities at the height of the temperature minimum?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Can granular fluctuations in the solar photosphere produce temperature inhomogeneities at the height of the temperature minimum? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1670097