Non detection of lightning signature in the Huygens RLF_VLF data

Details Non detection of lightning signature in the Huygens RLF_VLF data Non detection of lightning signature in the Huygens RLF_VLF data

Oct 2011

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011epsc.conf..583h&link_type=abstract

EPSC-DPS Joint Meeting 2011, held 2-7 October 2011 in Nantes, France. http://meetings.copernicus.org/epsc-dps2011, p.583

Other

Scientific paper

Long before Huygens landed on Titan, none of the two Voyager flybys had revealed any impulsive electromagnetic emission from Titan and the question of a possible lightning activity and related biochemistry reactions remained open. However, the modelling of the ionospheric altitude profile predicted the existence of multiple layers. The upper ones, induced by photons and precipitated energetic electrons were crossed by Cassini during its closest flybys, whereas the lower ionosphere, produced by galactic cosmic rays, was detected in situ during the descent of the Huygens probe. One of the main objectives of the Permittivity, Waves and Altimetry (PWA) experiment, a part of the Huygens Atmospheric Structure Instrument (HASI), was to measure in situ the electron and ion densities in the lower ionosphere with two different and overlapping techniques, a mutual impedance probe (MIP) and a relaxation probe (RP). MIP consists of a transmitting dipole that injects a known sinusoidal current in the medium and of a receiving dipole that measures the induced potential. The latter also measured the natural electromagnetic waves confined within the ionospheric cavity that could not be detected by the Voyager spacecraft, nor by Cassini. The two relevant frequency domains are the ELF range (~10-100 Hz), for the global Schumann resonance and its harmonics, and the VLF range (1-10 kHz), for the transverse resonances (tweeks). Average energy spectra were computed on board and telemetered to ground. The wideband electric receiver revealed the steady presence of an intense emission at 36 Hz throughout the descent, shown in fig. 1 that was reminiscent of a Schumann resonance [3,10]. The 36 Hz emission and its production mechanism was the subject of numerous investigations by the PWA team (see [1] and a companion presentation by Béghin et al., in GP3 Session ESPC-DPS2011- 194). No particular emission was observed in the VLF range. Another team of scientists led by J. Morente revisited the PWA data set and expressed a somewhat different opinion (see [5-7] for ELF and [4.8.9] for VLF). They claimed that these measurements carried the indication of a multitude of resonances and harmonics, thus irrefutably proving the existence of lightning activity on Titan. It can however be demonstrated that their interpretation is based on artefacts generated by an improper analysis of the data.

Affiliated with

Also associated with

No associations

Rating

Non detection of lightning signature in the Huygens RLF_VLF data does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Non detection of lightning signature in the Huygens RLF_VLF data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non detection of lightning signature in the Huygens RLF_VLF data will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1478440