A Reynolds-averaged turbulence modelling approach to the maintenance of the Venus superrotation

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

A maintenance mechanism of an approximately linear velocity profile of the Venus zonal flow or superrotation is explored, with the aid of a Reynolds-averaged turbulence modelling approach. The basic framework is similar to that of Gierasch (Meridional circulation and maintenance of the Venus atmospheric rotation. J. Atmos. Sci. 1975, 32, 1038-1044) in the sense that the mechanism is examined under a given meridional circulation. The profile mimicking the observations of the flow is initially assumed, and its maintenance mechanism in the presence of turbulence effects is investigated from a viewpoint of the suppression of energy cascade. In the present work, the turbulent viscosity is regarded as an indicator of the intensity of the cascade. A novelty of this formalism is the use of the isotropic turbulent viscosity based on a non-local time scale linked to a large-scale flow structure. The mechanism is first discussed qualitatively. On the basis of these discussions, the two-dimensional numerical simulation of the proposed model is performed, with an initially assumed superrotation, and the fast zonal flow is shown to be maintained, compared with the turbulent viscosity lacking the non-local time scale. The relationship of the present model with the current general circulation model simulation is discussed in light of a crucial role of the vertical viscosity.

Original languageEnglish
Pages (from-to)614-639
Number of pages26
JournalGeophysical and Astrophysical Fluid Dynamics
Volume107
Issue number6
DOIs
Publication statusPublished - 2013 Dec

Fingerprint

superrotation
Venus (planet)
Venus
maintenance
Turbulence
viscosity
turbulence
Viscosity
zonal flow
meridional circulation
modeling
cascades
turbulence effects
timescale
flow structure
Flow structure
velocity profile
simulation
general circulation model
velocity distribution

Keywords

  • Reynolds-averaged turbulence modelling
  • Superrotation
  • Turbulence suppression
  • Venus

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Geophysics
  • Mechanics of Materials
  • Computational Mechanics
  • Astronomy and Astrophysics

Cite this

@article{733e4714bd7047bcad116b133bc0c5eb,
title = "A Reynolds-averaged turbulence modelling approach to the maintenance of the Venus superrotation",
abstract = "A maintenance mechanism of an approximately linear velocity profile of the Venus zonal flow or superrotation is explored, with the aid of a Reynolds-averaged turbulence modelling approach. The basic framework is similar to that of Gierasch (Meridional circulation and maintenance of the Venus atmospheric rotation. J. Atmos. Sci. 1975, 32, 1038-1044) in the sense that the mechanism is examined under a given meridional circulation. The profile mimicking the observations of the flow is initially assumed, and its maintenance mechanism in the presence of turbulence effects is investigated from a viewpoint of the suppression of energy cascade. In the present work, the turbulent viscosity is regarded as an indicator of the intensity of the cascade. A novelty of this formalism is the use of the isotropic turbulent viscosity based on a non-local time scale linked to a large-scale flow structure. The mechanism is first discussed qualitatively. On the basis of these discussions, the two-dimensional numerical simulation of the proposed model is performed, with an initially assumed superrotation, and the fast zonal flow is shown to be maintained, compared with the turbulent viscosity lacking the non-local time scale. The relationship of the present model with the current general circulation model simulation is discussed in light of a crucial role of the vertical viscosity.",
keywords = "Reynolds-averaged turbulence modelling, Superrotation, Turbulence suppression, Venus",
author = "A. Yoshizawa and Hiromichi Kobayashi and Norihiko Sugimoto and N. Yokoi and Yutaka Shimomura",
year = "2013",
month = "12",
doi = "10.1080/03091929.2013.803546",
language = "English",
volume = "107",
pages = "614--639",
journal = "Geophysical and Astrophysical Fluid Dynamics",
issn = "0309-1929",
publisher = "Taylor and Francis Ltd.",
number = "6",

}

TY - JOUR

T1 - A Reynolds-averaged turbulence modelling approach to the maintenance of the Venus superrotation

AU - Yoshizawa, A.

AU - Kobayashi, Hiromichi

AU - Sugimoto, Norihiko

AU - Yokoi, N.

AU - Shimomura, Yutaka

PY - 2013/12

Y1 - 2013/12

N2 - A maintenance mechanism of an approximately linear velocity profile of the Venus zonal flow or superrotation is explored, with the aid of a Reynolds-averaged turbulence modelling approach. The basic framework is similar to that of Gierasch (Meridional circulation and maintenance of the Venus atmospheric rotation. J. Atmos. Sci. 1975, 32, 1038-1044) in the sense that the mechanism is examined under a given meridional circulation. The profile mimicking the observations of the flow is initially assumed, and its maintenance mechanism in the presence of turbulence effects is investigated from a viewpoint of the suppression of energy cascade. In the present work, the turbulent viscosity is regarded as an indicator of the intensity of the cascade. A novelty of this formalism is the use of the isotropic turbulent viscosity based on a non-local time scale linked to a large-scale flow structure. The mechanism is first discussed qualitatively. On the basis of these discussions, the two-dimensional numerical simulation of the proposed model is performed, with an initially assumed superrotation, and the fast zonal flow is shown to be maintained, compared with the turbulent viscosity lacking the non-local time scale. The relationship of the present model with the current general circulation model simulation is discussed in light of a crucial role of the vertical viscosity.

AB - A maintenance mechanism of an approximately linear velocity profile of the Venus zonal flow or superrotation is explored, with the aid of a Reynolds-averaged turbulence modelling approach. The basic framework is similar to that of Gierasch (Meridional circulation and maintenance of the Venus atmospheric rotation. J. Atmos. Sci. 1975, 32, 1038-1044) in the sense that the mechanism is examined under a given meridional circulation. The profile mimicking the observations of the flow is initially assumed, and its maintenance mechanism in the presence of turbulence effects is investigated from a viewpoint of the suppression of energy cascade. In the present work, the turbulent viscosity is regarded as an indicator of the intensity of the cascade. A novelty of this formalism is the use of the isotropic turbulent viscosity based on a non-local time scale linked to a large-scale flow structure. The mechanism is first discussed qualitatively. On the basis of these discussions, the two-dimensional numerical simulation of the proposed model is performed, with an initially assumed superrotation, and the fast zonal flow is shown to be maintained, compared with the turbulent viscosity lacking the non-local time scale. The relationship of the present model with the current general circulation model simulation is discussed in light of a crucial role of the vertical viscosity.

KW - Reynolds-averaged turbulence modelling

KW - Superrotation

KW - Turbulence suppression

KW - Venus

UR - http://www.scopus.com/inward/record.url?scp=84887988590&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84887988590&partnerID=8YFLogxK

U2 - 10.1080/03091929.2013.803546

DO - 10.1080/03091929.2013.803546

M3 - Article

AN - SCOPUS:84887988590

VL - 107

SP - 614

EP - 639

JO - Geophysical and Astrophysical Fluid Dynamics

JF - Geophysical and Astrophysical Fluid Dynamics

SN - 0309-1929

IS - 6

ER -