Book contents
- Frontmatter
- Contents
- Contributors
- Introduction
- Prologue 1 The genesis of Cassini-Huygens
- Prologue 2 Building a space flight instrument: a PI's perspective
- 1 The origin and evolution of Titan
- 2 Titan's surface geology
- 3 Thermal structure of Titan's troposphere and middle atmosphere
- 4 The general circulation of Titan's lower and middle atmosphere
- 5 The composition of Titan's atmosphere
- 6 Storms, clouds, and weather
- 7 Chemistry of Titan's atmosphere
- 8 Titan's haze
- 9 Titan's upper atmosphere: thermal structure, dynamics, and energetics
- 10 Titan's upper atmosphere/exosphere, escape processes, and rates
- 11 Titan's ionosphere
- 12 Titan's magnetospheric and plasma environment
- Index
- References
3 - Thermal structure of Titan's troposphere and middle atmosphere
Published online by Cambridge University Press: 05 January 2014
- Frontmatter
- Contents
- Contributors
- Introduction
- Prologue 1 The genesis of Cassini-Huygens
- Prologue 2 Building a space flight instrument: a PI's perspective
- 1 The origin and evolution of Titan
- 2 Titan's surface geology
- 3 Thermal structure of Titan's troposphere and middle atmosphere
- 4 The general circulation of Titan's lower and middle atmosphere
- 5 The composition of Titan's atmosphere
- 6 Storms, clouds, and weather
- 7 Chemistry of Titan's atmosphere
- 8 Titan's haze
- 9 Titan's upper atmosphere: thermal structure, dynamics, and energetics
- 10 Titan's upper atmosphere/exosphere, escape processes, and rates
- 11 Titan's ionosphere
- 12 Titan's magnetospheric and plasma environment
- Index
- References
Summary
3.1 Introduction
The thermal structure of an atmosphere is a product of radiative processes and dynamical transports. Indeed, the study of the distribution of temperature and pressure (as well as of winds and humidity) and its temporal behavior has played a key role in the development of terrestrial meteorology (Brunt, 1939). The distribution of gaseous constituents, produced by photo- or ion-chemistry, can affect atmospheric temperatures, if the gases are radiatively active, as does the distribution of clouds and aerosols. The redistribution of trace gases, clouds, and aerosols by atmospheric motions can materially affect an atmosphere's thermal structure.
Like Earth, Titan has a well defined troposphere, stratosphere, and mesosphere (the latter two layers comprise the middle atmosphere). Figure 3.1 depicts representative temperature profiles for the two atmospheres. Barometric pressure is used as the vertical coordinate. In these units the terrestrial and Titan profiles look roughly similar, except that Earth is much warmer, and its stratopause is at a higher pressure. Were the two sets of profiles depicted using geometric height instead of pressure as the vertical coordinate, Titan's temperature profile would look much more extended. This is mainly because its surface gravitational acceleration (g = 1.34 m s-2) is 14 percent that of Earth. Indeed, because Titan's atmosphere is so extended, the decrease of gravity with altitude matters.
- Type
- Chapter
- Information
- TitanInterior, Surface, Atmosphere, and Space Environment, pp. 102 - 121Publisher: Cambridge University PressPrint publication year: 2014
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