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Development of a Cloud Convection Model to Investigate the Jupiter's Atmosphere

Ko-ichiro Sugiyama (National Astronomical Observatory of Japan *1)
Masatsugu Odaka (Graduate School of Sciences, Hokkaido University)
Kensuke Nakajima (Faculty of Sciences, Kyushu University)
Yoshi-Yuki Hayashi (Graduate School of Science, Kobe University)

(Received 10 July, 2008; in revised form 23 January, 2009)

Abstract

We developed a two-dimensional cloud convection model that incorporates condensation of H2O and NH3 and the production reaction of NH4SH in order to examine the vertical profile of multi-composition clouds and characteristics of convective motion in Jupiter's atmosphere. The basic equations of the model are based on the quasi-compressible system[1] and the conservation equations of condensible species. Cloud microphysics and the effect of subgrid turbulence are implemented by the parameterization of Kessler (1969)[2] and Klemp and Wilhelmson (1978)[1], respectively. As a test run of the developed model, we perform a long-time numerical simulation of cloud convection driven by radiative cooling near the tropopause whose intensity is quite stronger than the real Jupiter. A visualization technique, "RGB composite", is proposed and employed in order to show the distribution of multi-composition clouds, and we examine both the vertical clouds structure of three-composition clouds and the characteristics of convective motion in a statistical equilibrium state. The result shows that H2O and NH4SH cloud particles are advected upward to altitudes above the NH3 condensation level, and cloud particles of all three species exist near the tropopause. The vertical cloud profiles are distinctly different from the classical three-layer structure that has been predicted by previous studies [3],[4]. The developed model is available form <URL: http://www.gfd-dennou.org/library/deepconv/index.htm.en>[5].

Contents

1. Introduction
2. Summary of the Developed Cloud Convection Model
2.1. Formulation
2.2. Discretization
2.3. Visualization of Multi-Composition Clouds
3. Long-Time Numerical Simulation of Cloud Convevtion
3.1. Set-up of the Experiment
3.2. Result (1): Vertical Motion and Atmospheric Structure
3.3. Result (2): Vertical Profiles of Clouds and Condensible Volatiles
3.4. Result (3): Static Stability
4. Summary

Appendix

A. Dynamic Framework
B. Thermodynamic Framework and Cloud Microphysical Model
C. Turbulent Mixing Parametarization
D. Artificial Dissipation Terms
E. Initial Mixing Ratios of Condensible Volatiles
F. Calculation of Thermodynamical Properties
G. Relationship between Static Stability and the Thermodynamical Variables
H. Acknowledgements
I. References
J. Authors and Addresses


*1: Present Affiliation: Graduate school of Sciences, Hokkaido University


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