Aerosols: The key to understanding Titan's lower ionosphere

作者：Molina Cuberos G J^*; Cardnell S; Garcia Collado A J; Witasse O; Lopez Moreno J J

来源：Planetary and Space Science, 2018, 153: 157-162.

DOI：10.1016/j.pss.2018.02.007

• Titan
• Comic rays
• Aerosols
• Charge concentration
• Ionosphere

The Permittivity Wave and Altimetry system on board the Huygens probe observed an ionospheric hidden layer at a much lower altitude than the main ionosphere during its descent through the atmosphere of Titan, the largest satellite of Saturn. Previous studies predicted a similar ionospheric layer. However, neither previous nor post Huygens theoretical models have been able to reproduce the measurements of the electrical conductivity and charge densities reported by the Mutual Impedance (MI) and Relaxation Probe (RP) sensors. The measurements were made from an altitude of 140 km down to the ground and show a maximum of charge densities of to approximate to 2 x 10(9) m(-3) positive ions and aa approximate to 450 x 10(6) m(-3) electrons at approximately 65 km. Such a large difference between positive and negative charge densities has not yet been understood. Here, by making use of electron and ion capture processes in to aerosols, we are able to model both electron and positive ion number densities and to reconcile experimental data and model results.

• 出版日期2018-4