Propagation of electromagnetic waves in the lower ionosphere of Titan

Towards the end of 2004 during the descent of the HUYGENS probe the Permittivity, Wave and Altimetry instrument (PWA) as part of the HASI experiment will investigate electrical properties and electric field fluctuations in the atmosphere of Titan below 170 km. We have modelled the propagation of low frequency electromagnetic waves in the lower ionosphere of Titan. The ionisation in this altitude range (below 400 km) is mainly produced by galactic cosmic rays. Electromagnetic waves could be generated by lightning phenomena at very low altitudes. A major emphasis of our work is on the calculation of the wave attenuation using the electron densities and collision frequencies from the model by Molina-Cuberos et al. (1999, J. Geophys. Res., 104, 21,997-22,024). © 2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.