Generation of Aerosol Particles via Nucleation of

Meteoric Dust and Cloud Upwelling in the Upper Haze of

VenusYuk Yung, Peter Gao,

Xi Zhang, David Crisp, and Charles G. Bardeen

DPS 44October 17th, 2012

Observations: The Upper Haze is variable on the order of days

Luz, D. et al. (2011) – 3.8 μm VIRTIS radiance maps of Polar Vortex

Observations: The Upper Haze is variable on the order of days

Luz, D. et al. (2011) – 3.8 μm VIRTIS radiance maps of Polar Vortex

Markiewicz, W. J. et al. (2007) – UV images from VMC of southern hemisphere

Observations: Upper Haze variability is variable

Wilquet, V. et al. (2012) – Extinction profiles from solar occultations during mid 2007 (top) and early 2008 (bottom)

Observations: Upper Haze variability is variable

Wilquet, V. et al. (2012) – Extinction profiles from solar occultations during mid 2007 (top) and early 2008 (bottom)

Understanding the variability of the

Upper Haze leads to insights on atmospheric dynamics,

chemistry, and the interactions

between the hazes and the clouds.

CARMA 3.0• 1D aerosol microphysics + vertical transport model• Developed by Turco, R. P. et al.(1979)• Upgraded to version 3.0 by Bardeen, C. G. et al. (2011)

CARMA 3.0• 1D aerosol microphysics + vertical transport model• Developed by Turco, R. P. et al.(1979)• Upgraded to version 3.0 by Bardeen, C. G. et al. (2011)Model Setup• Standard Venus atmosphere from Seiff, A. et al. (1985).• Sulfate/sulfur nuclei + sulfuric acid vapour production rates from Imamura, T. and Hashimoto, G. L. (2001).• Eddy diffusion coefficient from Imamura, T. and Hashimoto, G. L. (2001) and Hunten, D. M. et al. (1983).• Meteoric dust production profile from Kalashnikova, O. et al. (2000).• Run for 107 seconds.

Results: Number density and particle size

Results: Number density and particle size

Mode 2’ or 3?

Mode 2

Mode 1

Results: Gas concentration vs. data

Radio OccultationsSVP

Model Results

Results: Number density vs. data

LCPS

Results: Upper haze size distribution

78 km81 km84 km

88 km93 km

Results: Upper haze size distribution

Meteoric dust production only

Sulfur nuclei production only

Both

78 km81 km84 km

88 km93 km

Results: Upper haze size distribution

Meteoric dust production only

Sulfur nuclei production only

Both

The Upper Haze appears to be a mix of particles nucleated in situ and upwelling

cloud particles.

78 km81 km84 km

88 km93 km

Results: A qualitative look at the 2 “modes”

“Large mode”

“Small mode”

Results: A qualitative look at the 2 “modes”

“Large mode”

“Small mode”

Results: Wind effects (preliminary)

Results: Wind effects (preliminary)

Solid – Original distributionDotted – After 105s of winds

Dashed – 105s after end of winds

Conclusions

Conclusions

1. CARMA 3.0 can reproduce fairly accurately the number density of aerosols vs. altitude, as detected by Pioneer Venus’ LCPS.

Conclusions

1. CARMA 3.0 can reproduce fairly accurately the number density of aerosols vs. altitude, as detected by Pioneer Venus’ LCPS.

2. Modes 1 and 2 can be seen in the resulting size distributions, with a possible mode 2’ or 3 at lower altitudes.

Conclusions

1. CARMA 3.0 can reproduce fairly accurately the number density of aerosols vs. altitude, as detected by Pioneer Venus’ LCPS.

2. Modes 1 and 2 can be seen in the resulting size distributions, with a possible mode 2’ or 3 at lower altitudes.

3. The upper haze appears to be a mix of particles nucleated in situ and upwelling cloud particles.

Conclusions

1. CARMA 3.0 can reproduce fairly accurately the number density of aerosols vs. altitude, as detected by Pioneer Venus’ LCPS.

2. Modes 1 and 2 can be seen in the resulting size distributions, with a possible mode 2’ or 3 at lower altitudes.

3. The upper haze appears to be a mix of particles nucleated in situ and upwelling cloud particles.

4. Qualitatively splitting the equilibrium upper haze size distribution into a small and large mode results in number densities of the modes matching the data within a factor of 2-3.

Conclusions

1. CARMA 3.0 can reproduce fairly accurately the number density of aerosols vs. altitude, as detected by Pioneer Venus’ LCPS.

2. Modes 1 and 2 can be seen in the resulting size distributions, with a possible mode 2’ or 3 at lower altitudes.

3. The upper haze appears to be a mix of particles nucleated in situ and upwelling cloud particles.

4. Qualitatively splitting the equilibrium upper haze size distribution into a small and large mode results in number densities of the modes matching the data within a factor of 2-3.

5. Transient winds lasting about a day can increase the number density of the upper haze by an order of magnitude and create multi-modal size distributions, matching the observations, at least qualitatively.

THE END

Yuk Yung, Peter Gao, Xi Zhang, David Crisp, and

Charles G. BardeenDPS 44

October 17th, 2012

Model Setup Imamura, T. and Hashimoto, G. L. (2001)

Model Setup Kalashnikova, O. et al. (2000)

Meteoric DustProduction Profile

Model Setup Seiff, A. et al. (1985)

Model Setup Seiff, A. et al. (1985)

Model Setup Imamura, T. and Hashimoto, G. L. (2001) and Hunten, D. M. et al. (1983)