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Are granules good tracers of solar surface velocity fields?

Rieutord, M; Roudier, T; Ludwig, Hans-Günter LU ; Nordlund, Å and Stein, R (2001) In Astronomy & Astrophysics 377. p.14-17
Abstract
Using a numerical simulation of compressible convection with radiativetransfer mimicking the solar photosphere, we compare the velocity fieldderived from granule motions to the actual velocity field of the plasma.We thus test the idea that granules may be used to trace large-scalevelocity fields at the sun's surface. Our results show that this isindeed the case provided the scale separation is sufficient. We thusestimate that neither velocity fields at scales less than 2500 km nortime evolution at scales shorter than 0.5 hr can be faithfully describedby granules. At larger scales the granular motions correlate linearlywith the underlying fluid motions with a slope of ≲2 reachingcorrelation coefficients up to ~ 0.9.
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
CONVECTION, SUN: GRANULATION, SUN: PHOTOSPHERE
in
Astronomy & Astrophysics
volume
377
pages
14 - 17
publisher
EDP Sciences
external identifiers
  • scopus:0035493989
ISSN
0004-6361
DOI
10.1051/0004-6361:20011160
language
English
LU publication?
yes
id
d1ad6668-0500-43ce-8f96-7a10fb5634cf (old id 130140)
date added to LUP
2007-07-13 15:03:45
date last changed
2018-04-15 04:08:32
@article{d1ad6668-0500-43ce-8f96-7a10fb5634cf,
  abstract     = {Using a numerical simulation of compressible convection with radiativetransfer mimicking the solar photosphere, we compare the velocity fieldderived from granule motions to the actual velocity field of the plasma.We thus test the idea that granules may be used to trace large-scalevelocity fields at the sun's surface. Our results show that this isindeed the case provided the scale separation is sufficient. We thusestimate that neither velocity fields at scales less than 2500 km nortime evolution at scales shorter than 0.5 hr can be faithfully describedby granules. At larger scales the granular motions correlate linearlywith the underlying fluid motions with a slope of ≲2 reachingcorrelation coefficients up to ~ 0.9.},
  author       = {Rieutord, M and Roudier, T and Ludwig, Hans-Günter and Nordlund, Å and Stein, R},
  issn         = {0004-6361},
  keyword      = {CONVECTION,SUN: GRANULATION,SUN: PHOTOSPHERE},
  language     = {eng},
  pages        = {14--17},
  publisher    = {EDP Sciences},
  series       = {Astronomy & Astrophysics},
  title        = {Are granules good tracers of solar surface velocity fields?},
  url          = {http://dx.doi.org/10.1051/0004-6361:20011160},
  volume       = {377},
  year         = {2001},
}