Coupled Ion and Coupled Ion and Neutral Neutral Rotating Model Rotating Model of Titan’s of Titan’s Upper Upper Atmosphere Atmosphere V. De La Haye et. al. V. De La Haye et. al. (2008) (2008) Joseph Westlake University of Texas at San Antonio Southwest Research Institute [email protected]
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Coupled Ion and Neutral Rotating Model of Titan’s Upper Atmosphere V. De La Haye et. al. (2008)
Coupled Ion and Neutral Rotating Model of Titan’s Upper Atmosphere V. De La Haye et. al. (2008). Joseph Westlake University of Texas at San Antonio Southwest Research Institute [email protected]. Coupled ion and neutral rotating model of Titan’s upper atmosphere. Included processes - PowerPoint PPT Presentation
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Coupled Ion and Coupled Ion and Neutral Rotating Neutral Rotating Model of Titan’s Model of Titan’s
Upper Upper AtmosphereAtmosphere
V. De La Haye et. al. (2008)V. De La Haye et. al. (2008)
Coupled ion and neutral rotating Coupled ion and neutral rotating model of Titan’s upper atmospheremodel of Titan’s upper atmosphere
• Included processes– Photodissociation– Neutral chemistry– Ion-neutral chemistry– Electron recombination to
neutral production
• Also has a simplified chemical scheme (19 species)
• TA and T5 model runs published in De La Haye et al. (2008)
• 1-D composition model.• 36 neutral species• 47 ions • Both solar and magnetospheric energy inputs included • Rotation to account for diurnal variations
Ion Neutral Temp. Model:Ion Neutral Temp. Model: the rotating model – time constants the rotating model – time constants
considerationsconsiderations
• Comparison of the time constants:
– Time constants for neutral chemistry, diffusion and thermal structure are comparable to a Titan rotation zenith angle variation with day and night should be taken into account.
– The ion lifetimes are extremely short assumed to be instantaneous
Ion Neutral Temp. Model:Ion Neutral Temp. Model: modeling the atmospheric neutrals - modeling the atmospheric neutrals -
implementationimplementation
• The Chemistry Equation:
• Crank Nicholson Scheme:
• Solved for all species simultaneously using the Thomas algorithm
– Transform the tridiagonal matrix into an upper-triangular matrix then compute the unknown densities by taking into account the upper and lower boundary conditions and using back substitution (Tannehill et al., 1997)