Publication Abstracts
Canuto 2011
, 2011: Stellar mixing: III. The case of a passive tracer. Astron. Astrophys., 528, A78, doi:10.1051/0004-6361/201015372.
In Papers I-II, we derived the expressions for the turbulent diffusivities of momentum, temperature T, and mean molecular weight μ. Since the scalar T-μ fields are active tracers (by influencing the density and thus the velocity field), whereas passive tracers such as 7Li are carried along by the flow without influencing it, it would be unjustified to use the diffusivities of the T-μ fields to represent the diffusivity of passive tracers. In this paper, we present the first derivation of a passive tracer diffusivity. Some key results are: a) In the general 3D case, the passive tracer diffusivity is a tensor given in algebraic form; b) the diffusivity tensor depends on shear, vorticity, T, and μ-gradients, thus including double diffusion and differential rotation; c) in the 1D version of the model, the passive tracer diffusivity is a scalar denoted by Kc; d) in doubly stable regimes, ∇μ > 0, ∇-∇ad < 0, Kc is nearly the same as those of the T-μ fields; e) in semi-convection regimes, ∇μ > 0, ∇-∇ad > 0, Kc is larger than that of the μ-field; f) in salt fingers regimes ∇μ < 0, ∇-∇ad < 0, Kc is smaller than that of the μ-field; and finally, g) in the only case we know of a direct measurement of a passive tracer diffusivity, the oceanographic North Atlantic Tracer Release Experiment (NATRE), the model reproduces the data quite closely.
Export citation: [ BibTeX ] [ RIS ]
BibTeX Citation
@article{ca07320o,
author={Canuto, V. M.},
title={Stellar mixing: III. The case of a passive tracer},
year={2011},
journal={Astronomy and Astrophysics},
volume={528},
pages={A78},
doi={10.1051/0004-6361/201015372},
}
[ Close ]
RIS Citation
TY - JOUR ID - ca07320o AU - Canuto, V. M. PY - 2011 TI - Stellar mixing: III. The case of a passive tracer JA - Astron. Astrophys. JO - Astronomy and Astrophysics VL - 528 SP - A78 DO - 10.1051/0004-6361/201015372 ER -
[ Close ]
