Turbulence and anomalous heat fluxes in the atmospheres of Mars and Venus

2012

Vertical profiles of the turbulence parameters calculated for the planet averaged conditions from the experimental data on the turbulent fluctuations of temperature and wind velocity are presented. Improved formulas accounting for the difference between the atmospheric gas on Venus and an ideal one, and the large difference in its thermal capacity at different altitudes, are used. The commonly used formula for the poten tial temperature describing the atmospheres of the Earth and Mars is inapplicable to the atmosphere of Venus. It has been shown that the opinion on the absence of turbulence in the atmosphere of Venus is based on over estimated values of the dynamic Richardson number obtained from the smoothed profiles of wind velocity, while its actual values are below unity due to the large wind velocity gradients produced by buoyancy waves. To improve the global circulation models of the atmosphere of Venus, it is necessary to use the currently avail able turbulence parameters calculated from experimental data.

“…In this case, the shear (Kelvin-Helmholtz) instability induces turbulence (see, e.g., Shakina, 1990;Izakov, 2001;2007).…”

Section: The Small Scale Turbulence Parameters Of the Atmospherementioning

confidence: 99%

“…7). It is convenient to call this amazing phenomenon anomalous turbulent convec tion (Izakov, 2001;2007).…”

Section: The Small Scale Turbulence Parameters Of the Atmosphereunclassified

Section: The Small Scale Turbulence Parameters Of the Atmospherementioning

confidence: 99%

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On the small-scale turbulence parameters in the atmosphere of venus and their use in the global circulation models

2012

“…The author, in his previous papers, summarized the experimental data and theoretical estimates to show that turbulence is permanently present in the atmosphere of Venus up to its turbopause and considerably affects its composition, thermal regime, and dynamics. It was shown why some authors had previously proclaimed turbulence to be absent on Venus and under which conditions turbulence occurs at stable stratification (Izakov, 2001a(Izakov, , 2001b(Izakov, , 2002a(Izakov, , 2002b(Izakov, , 2003.…”

Section: Introductionmentioning

confidence: 99%

Turbulence in the troposphere of Venus: refined characteristics and new estimates

2005

Based on spaceborne experimental data, characteristics of turbulence are calculated for the Venusian troposphere under conditions corresponding to the planet-averaged flux of solar radiation, which is equal to its value at a solar zenith angle of 66 ° . Additionally, given experimental data on radiation fluxes and their numerical calculations, turbulence characteristics were calculated for a solar zenith angle of 45 ° . The turbulence pattern is significantly different for small and large solar zenith angles. At large solar zenith angles, there exist an anomalous downward turbulent heat flux above 7-10 km and a normal upward flux at lower heights. At small zenith angles, the turbulent flux is normal throughout the entire troposphere. The dissipation of turbulent energy contributes significantly to the atmospheric heating in a wide range of altitudes. The spectrum of the time and space scales of dissipative processes in the troposphere is very wide and changes with height.

“…One of these problems is whether turbulence exists in the atmosphere of Venus and what its role might be. It was shown why some authors had previously proclaimed turbulence to be absent on Venus and under which conditions turbulence occurs at stable stratification (Izakov, 2001a(Izakov, , 2001b(Izakov, , 2002a(Izakov, , 2002b(Izakov, , 2003. The author, in his previous papers, summarized the experimental data and theoretical estimates to show that turbulence is permanently present in the atmosphere of Venus up to its turbopause and considerably affects its composition, thermal regime, and dynamics.…”

Section: Introductionmentioning

confidence: 99%

Turbulence in the troposphere of Venus: Refined characteristics and new estimates

2005