SwePub
Sök i LIBRIS databas

  Utökad sökning

onr:"swepub:oai:DiVA.org:uu-263043"
 

Sökning: onr:"swepub:oai:DiVA.org:uu-263043" > Influence of local ...

Influence of local ionization on ionospheric densities in Titan's upper atmosphere

Sagnieres, Luc B. M. (författare)
Univ London, London, England
Galand, Marina (författare)
Univ London, London, England
Cui, Jun (författare)
Chinese Acad Sci, Beijing, Peoples R China
visa fler...
Lavvas, Panayotis P. (författare)
Univ Reims, Reims, France
Vigren, Erik (författare)
Uppsala universitet,Institutet för rymdfysik, Uppsalaavdelningen
Vuitton, Veronique (författare)
Inst Planetol & Astrophys Grenoble, Grenoble, France
Yelle, Roger V. (författare)
Univ Arizona, Tucson, USA
Wellbrock, Anne (författare)
Univ Coll London, England.
Coates, Andrew J. (författare)
Univ Coll London, England.
visa färre...
 (creator_code:org_t)
2015
2015
Engelska.
Ingår i: Journal of Geophysical Research - Space Physics. - 2169-9380 .- 2169-9402. ; 120:7, s. 5899-5921
  • Tidskriftsartikel (refereegranskat)
Abstract Ämnesord
Stäng  
  • Titan has the most chemically complex ionosphere of the solar system. The main sources of ions on the dayside are ionization by EUV solar radiation and on the nightside include ionization by precipitated electrons from Saturn's magnetosphere and transport of ions from the dayside, but many questions remain open. How well do models predict local ionization rates? How strongly do the ionization processes drive the ionospheric densities locally? To address these questions, we have carried out an analysis of ion densities from the Ion and Neutral Mass Spectrometer (INMS) from 16 close flybys of Titan's upper atmosphere. Using a simple chemical model applied to the INMS data set, we have calculated the ion production rates and local ionization frequencies associated with primary ions and . We find that on the dayside the solar energy deposition model overestimates the INMS-derived production rates by a factor of 2. On the nightside, however, the model driven by suprathermal electron intensities from the Cassini Plasma Spectrometer Electron Spectrometer sometimes agrees and other times underestimates the INMS-derived production rates by a factor of up to 2-3. We find that below 1200km, all ion number densities correlate with the local ionization frequency, although the correlation is significantly stronger for short-lived ions than long-lived ions. Furthermore, we find that, for a given N-2 local ionization frequency, has higher densities on the dayside than on the nightside. We explain that this is due to CH4 being more efficiently ionized by solar photons than by magnetospheric electrons for a given amount of N-2 ionization.

Ämnesord

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)
NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

Nyckelord

Titan
ionization processes
Cassini
upper atmosphere

Publikations- och innehållstyp

ref (ämneskategori)
art (ämneskategori)

Hitta via bibliotek

Till lärosätets databas

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy