Predictions of the electrical conductivity and charging of the aerosols in Titan's nighttime atmosphere Journal Article uri icon



  • The electrical conductivity and electrical charge on Titan's atmosphere are computed for altitudes between 0 and 400 km on the nightside for which the main source of ionization is galactic cosmic rays (GCR). Unlike the dayside, electrical charging of the aerosol particles at night is not only negative but also time‐dependent. Hence a time‐dependent model must be employed for computations of electron and ion densities as well as aerosol charging over the night hemisphere. After developing a method for computing the time‐dependent charge states of the aerosol particles, we found that that at altitudes above about 60 km (the effusion range) the charging of the aerosols at the antisolar point is quite close to that at steady state; however, at lower altitudes where (the slow) diffusion of the electrons and ions prevails, the electron density is larger (and the charging of the aerosol particles is smaller) than at steady state. Because polycyclic aromatic hydrocarbons (PAHs) are expected in Titan's atmosphere and have been observed in the laboratory and found to be electrophillic, we have included the formation of negative ions in the aerosol charging model. Such ions are of major importance at night between about 170 and 360 km where they capture most of the negative charge. As a result they greatly reduce the electron density and thus the electrical conductivity in that altitude range. The charge distributions at 50 km (diffusion range), 150 km (effusion range with few negative ions), and 250 km (effusion range) are presented.

publication date

  • April 1, 2007

has restriction

  • closed

Date in CU Experts

  • June 9, 2014 3:42 AM

Full Author List

  • Whitten RC; Borucki WJ; Tripathi S

author count

  • 3

Other Profiles

International Standard Serial Number (ISSN)

  • 0148-0227

Additional Document Info


  • 112


  • E4