On the amount of heavy molecular ions in Titan's ionosphere

J. E. Wahlund, M. Galand, I. Müller-Wodarg, J. Cui, Roger Yelle, F. J. Crary, K. Mandt, B. Magee, J. H. Waite, D. T. Young, A. J. Coates, P. Garnier, K. Ågren, M. André, A. I. Eriksson, T. E. Cravens, V. Vuitton, D. A. Gurnett, W. S. Kurth

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

We present observational evidence that the ionosphere of Titan below an altitude of 1150 km is a significant source of heavy (>100 amu) molecular organic species. This study is based on measurements by five instruments (RPWS/LP, RPWS/E, INMS, CAPS/ELS, CAPS/IBS) onboard the Cassini spacecraft during three flybys (T17, T18, T32) of Titan. The ionospheric peaks encountered at altitudes of 950-1300 km had densities in the range 900-3000 cm-3. Below these peaks the number densities of heavy positively charged ions reached 100-2000 cm-3 and approached 50-70% of the total ionospheric density with an increasing trend toward lowest measured altitudes. Simultaneously measured negatively charged ion densities were in the range 50-150 cm-3. These results imply that ~105-106 heavy positively charged ions/m3/s are continuously recombining into heavy neutrals and supply the atmosphere of Titan. The ionosphere may in this way produce 0.1-1 Mt/yr of heavy organic compounds and is therefore a sizable source for aerosol formation. We also predict that Titan's ionosphere is dominated by heavy (>100 amu) molecular ions below 950 km.

Original languageEnglish (US)
Pages (from-to)1857-1865
Number of pages9
JournalPlanetary and Space Science
Volume57
Issue number14-15
DOIs
StatePublished - Dec 2009

Fingerprint

Titan
molecular ions
ionospheres
ionosphere
heavy ions
ion
caps
ionospherics
aerosol formation
low altitude
organic compounds
organic compound
aerosols
ions
spacecraft
trends
atmospheres
atmosphere

Keywords

  • Aerosol formation
  • Cassini
  • Heavy molecular ions
  • Ionospheric physics
  • Titan aeronomy
  • Titan's ionosphere

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Wahlund, J. E., Galand, M., Müller-Wodarg, I., Cui, J., Yelle, R., Crary, F. J., ... Kurth, W. S. (2009). On the amount of heavy molecular ions in Titan's ionosphere. Planetary and Space Science, 57(14-15), 1857-1865. https://doi.org/10.1016/j.pss.2009.07.014

On the amount of heavy molecular ions in Titan's ionosphere. / Wahlund, J. E.; Galand, M.; Müller-Wodarg, I.; Cui, J.; Yelle, Roger; Crary, F. J.; Mandt, K.; Magee, B.; Waite, J. H.; Young, D. T.; Coates, A. J.; Garnier, P.; Ågren, K.; André, M.; Eriksson, A. I.; Cravens, T. E.; Vuitton, V.; Gurnett, D. A.; Kurth, W. S.

In: Planetary and Space Science, Vol. 57, No. 14-15, 12.2009, p. 1857-1865.

Research output: Contribution to journalArticle

Wahlund, JE, Galand, M, Müller-Wodarg, I, Cui, J, Yelle, R, Crary, FJ, Mandt, K, Magee, B, Waite, JH, Young, DT, Coates, AJ, Garnier, P, Ågren, K, André, M, Eriksson, AI, Cravens, TE, Vuitton, V, Gurnett, DA & Kurth, WS 2009, 'On the amount of heavy molecular ions in Titan's ionosphere', Planetary and Space Science, vol. 57, no. 14-15, pp. 1857-1865. https://doi.org/10.1016/j.pss.2009.07.014
Wahlund JE, Galand M, Müller-Wodarg I, Cui J, Yelle R, Crary FJ et al. On the amount of heavy molecular ions in Titan's ionosphere. Planetary and Space Science. 2009 Dec;57(14-15):1857-1865. https://doi.org/10.1016/j.pss.2009.07.014
Wahlund, J. E. ; Galand, M. ; Müller-Wodarg, I. ; Cui, J. ; Yelle, Roger ; Crary, F. J. ; Mandt, K. ; Magee, B. ; Waite, J. H. ; Young, D. T. ; Coates, A. J. ; Garnier, P. ; Ågren, K. ; André, M. ; Eriksson, A. I. ; Cravens, T. E. ; Vuitton, V. ; Gurnett, D. A. ; Kurth, W. S. / On the amount of heavy molecular ions in Titan's ionosphere. In: Planetary and Space Science. 2009 ; Vol. 57, No. 14-15. pp. 1857-1865.
@article{42f3cfe8ac334d41ac8f2a28f2b3accf,
title = "On the amount of heavy molecular ions in Titan's ionosphere",
abstract = "We present observational evidence that the ionosphere of Titan below an altitude of 1150 km is a significant source of heavy (>100 amu) molecular organic species. This study is based on measurements by five instruments (RPWS/LP, RPWS/E, INMS, CAPS/ELS, CAPS/IBS) onboard the Cassini spacecraft during three flybys (T17, T18, T32) of Titan. The ionospheric peaks encountered at altitudes of 950-1300 km had densities in the range 900-3000 cm-3. Below these peaks the number densities of heavy positively charged ions reached 100-2000 cm-3 and approached 50-70{\%} of the total ionospheric density with an increasing trend toward lowest measured altitudes. Simultaneously measured negatively charged ion densities were in the range 50-150 cm-3. These results imply that ~105-106 heavy positively charged ions/m3/s are continuously recombining into heavy neutrals and supply the atmosphere of Titan. The ionosphere may in this way produce 0.1-1 Mt/yr of heavy organic compounds and is therefore a sizable source for aerosol formation. We also predict that Titan's ionosphere is dominated by heavy (>100 amu) molecular ions below 950 km.",
keywords = "Aerosol formation, Cassini, Heavy molecular ions, Ionospheric physics, Titan aeronomy, Titan's ionosphere",
author = "Wahlund, {J. E.} and M. Galand and I. M{\"u}ller-Wodarg and J. Cui and Roger Yelle and Crary, {F. J.} and K. Mandt and B. Magee and Waite, {J. H.} and Young, {D. T.} and Coates, {A. J.} and P. Garnier and K. {\AA}gren and M. Andr{\'e} and Eriksson, {A. I.} and Cravens, {T. E.} and V. Vuitton and Gurnett, {D. A.} and Kurth, {W. S.}",
year = "2009",
month = "12",
doi = "10.1016/j.pss.2009.07.014",
language = "English (US)",
volume = "57",
pages = "1857--1865",
journal = "Planetary and Space Science",
issn = "0032-0633",
publisher = "Elsevier Limited",
number = "14-15",

}

TY - JOUR

T1 - On the amount of heavy molecular ions in Titan's ionosphere

AU - Wahlund, J. E.

AU - Galand, M.

AU - Müller-Wodarg, I.

AU - Cui, J.

AU - Yelle, Roger

AU - Crary, F. J.

AU - Mandt, K.

AU - Magee, B.

AU - Waite, J. H.

AU - Young, D. T.

AU - Coates, A. J.

AU - Garnier, P.

AU - Ågren, K.

AU - André, M.

AU - Eriksson, A. I.

AU - Cravens, T. E.

AU - Vuitton, V.

AU - Gurnett, D. A.

AU - Kurth, W. S.

PY - 2009/12

Y1 - 2009/12

N2 - We present observational evidence that the ionosphere of Titan below an altitude of 1150 km is a significant source of heavy (>100 amu) molecular organic species. This study is based on measurements by five instruments (RPWS/LP, RPWS/E, INMS, CAPS/ELS, CAPS/IBS) onboard the Cassini spacecraft during three flybys (T17, T18, T32) of Titan. The ionospheric peaks encountered at altitudes of 950-1300 km had densities in the range 900-3000 cm-3. Below these peaks the number densities of heavy positively charged ions reached 100-2000 cm-3 and approached 50-70% of the total ionospheric density with an increasing trend toward lowest measured altitudes. Simultaneously measured negatively charged ion densities were in the range 50-150 cm-3. These results imply that ~105-106 heavy positively charged ions/m3/s are continuously recombining into heavy neutrals and supply the atmosphere of Titan. The ionosphere may in this way produce 0.1-1 Mt/yr of heavy organic compounds and is therefore a sizable source for aerosol formation. We also predict that Titan's ionosphere is dominated by heavy (>100 amu) molecular ions below 950 km.

AB - We present observational evidence that the ionosphere of Titan below an altitude of 1150 km is a significant source of heavy (>100 amu) molecular organic species. This study is based on measurements by five instruments (RPWS/LP, RPWS/E, INMS, CAPS/ELS, CAPS/IBS) onboard the Cassini spacecraft during three flybys (T17, T18, T32) of Titan. The ionospheric peaks encountered at altitudes of 950-1300 km had densities in the range 900-3000 cm-3. Below these peaks the number densities of heavy positively charged ions reached 100-2000 cm-3 and approached 50-70% of the total ionospheric density with an increasing trend toward lowest measured altitudes. Simultaneously measured negatively charged ion densities were in the range 50-150 cm-3. These results imply that ~105-106 heavy positively charged ions/m3/s are continuously recombining into heavy neutrals and supply the atmosphere of Titan. The ionosphere may in this way produce 0.1-1 Mt/yr of heavy organic compounds and is therefore a sizable source for aerosol formation. We also predict that Titan's ionosphere is dominated by heavy (>100 amu) molecular ions below 950 km.

KW - Aerosol formation

KW - Cassini

KW - Heavy molecular ions

KW - Ionospheric physics

KW - Titan aeronomy

KW - Titan's ionosphere

UR - http://www.scopus.com/inward/record.url?scp=70449527525&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70449527525&partnerID=8YFLogxK

U2 - 10.1016/j.pss.2009.07.014

DO - 10.1016/j.pss.2009.07.014

M3 - Article

AN - SCOPUS:70449527525

VL - 57

SP - 1857

EP - 1865

JO - Planetary and Space Science

JF - Planetary and Space Science

SN - 0032-0633

IS - 14-15

ER -