Understanding the Structure and Energetics of Titan's Upper Atmosphere

ORAL

Abstract

Over the past 10 years, Cassini has directly observed the very upper regions of Titan's atmosphere with a suite of instruments. One of the most surprising discoveries is that the production of the complex organic haze appears to begin at the high altitudes observed by Cassini. This part of the atmosphere is not well understood on any planet and significant questions remain about the competing influences of the Sun, the charged particles and electrodynamic fields in Titan's space environment, and atmospheric waves. Previous work (e.g. Snowden et al. (2014)) showed that energy deposition rates in Titan's atmosphere due to the precipitation of magnetospheric electrons and ions are small compared to the energy flux due to solar EUV. However, some of these results relied on energy flux rates at Titan's exobase calculated from Voyager 1 data or data from a small number of Cassini flybys. Cassini has shown that the plasma environment around Titan is extremely variable and that the Voyager 1 conditions are not characteristic of an average plasma environment. Therefore, we further investigate the issue using particle tracing simulations for ions and a two-stream model for electrons in combination with a 3D model of Titan's induced magnetosphere.

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Authors

  • Darci Snowden

    Central Washington University

  • Mike Smith

    University of Kentucky, Michigan State University, University of Guelph, TRIUMF, Colorado School of Mines, Simon Fraser University, University of Texas at Dallas, Washington State University, Okinawa Institute of Science and Technology Graduate University, Japan, Institute for Quantum Science and Technology, University of Calgary, University of British Columbia, School of Physics and Astronomy, Tel Aviv U., Cyclotron Institute and Dept. of Physics and Astronomy, Texas A\&M U., Dept. of Physics and Astronomy, U. Manitoba, Dept. of Physics and Astronomy, U. British Columbia, TRIUMF, Vancouver, British Columbia, Department of Physics and Astronomy, University of Calgary, Institut f{\"u}r Kernphysik, Westf{\"a}lische Wilhelms-Universit{\"a}t, M{\"u}nster, Germany, Simon Fraser U./TRIUMF, U. British Columbia/TRIUMF, MPIK/TRIUMF, U. Manitoba, U. Surrey, TRIUMF/U. British Columbia, U. Manitoba/TRIUMF, McGill U., Simon Fraser U., Queen Mary University of London, Harvard University, University of Lethbridge, Georgia Institute of Technology, St. Mary's University, University of Washington, University of Auckland, Central Washington University

  • Mike Smith

    University of Kentucky, Michigan State University, University of Guelph, TRIUMF, Colorado School of Mines, Simon Fraser University, University of Texas at Dallas, Washington State University, Okinawa Institute of Science and Technology Graduate University, Japan, Institute for Quantum Science and Technology, University of Calgary, University of British Columbia, School of Physics and Astronomy, Tel Aviv U., Cyclotron Institute and Dept. of Physics and Astronomy, Texas A\&M U., Dept. of Physics and Astronomy, U. Manitoba, Dept. of Physics and Astronomy, U. British Columbia, TRIUMF, Vancouver, British Columbia, Department of Physics and Astronomy, University of Calgary, Institut f{\"u}r Kernphysik, Westf{\"a}lische Wilhelms-Universit{\"a}t, M{\"u}nster, Germany, Simon Fraser U./TRIUMF, U. British Columbia/TRIUMF, MPIK/TRIUMF, U. Manitoba, U. Surrey, TRIUMF/U. British Columbia, U. Manitoba/TRIUMF, McGill U., Simon Fraser U., Queen Mary University of London, Harvard University, University of Lethbridge, Georgia Institute of Technology, St. Mary's University, University of Washington, University of Auckland, Central Washington University