[P-PS01] Outer Solar System Exploration Today, and Tomorrow

12:30 PM - 12:45 PM JST(3:30 AM - 3:45 AM UTC)

[PPS01-03] Simulation study of Jupiter's stratosphere: development of a new radiation code and impacts on the dynamics

*Takeshi KURODA¹, Alexander S. Medvedev², Jisesh Sethunadh², Paul Hartogh² (1.Planetary Plasma and Atmospheric Research Center, Tohoku University, 2.Max Planck Institute for Solar System Research)

Keywords:

Jupiter,Stratosphere,Atmospheric radiation,Atmospheric dynamics,Gas giants,JUICE

We have developed a new radiation code of radiative heating and cooling for Jupiter's upper troposphere and stratosphere (10³ to 10^-3 hPa) suitable for general circulation models (GCMs). It is based on the correlated k-distribution approach, and accounts for all the major radiative mechanisms in the Jovian atmosphere (heating due to absorption of solar radiation by CH₄, and cooling in the infrared by C₂H₆, C₂H₂, CH₄ and collision-induced transitions of H₂-H₂ and H₂-He). The code can be applied for Saturn and extrasolar gas giants. Vertical 1-D calculations using this code demonstrated that temperature of Jupiter's stratosphere is close to radiative-convective equilibrium, and that the radiative relaxation time decreases exponentially with height (from 10⁸ s near the tropopause to 10⁵ s in the upper stratosphere). The latter differs from the study of Conrath et al. (1990), which showed the very long (〜10⁸ s) relaxation time approximately constant throughout the stratosphere. Our calculations with the GCM show that the radiative relaxation time suggested by Conrath et al. (1990) is too long, and cannot sustain convergence of model solutions. With the newly derived vertical profile of relaxation time, simulations converge and produce realistic temperature and wind in Jovian stratosphere.