Planetary atmospheres physical properties

Table 1 compares physical parameters of the planetary atmospheres discussed below. We separate these into two groups (1) the terrestrial planets (Venus, Earth, and Mars), and (2) the gas giant planets (Jupiter, Saturn, Uranus, and Neptune). Properties for the terrestrial planets are given at the observed surface conditions. Properties for the gas giant planets, which do not have observable solid surfaces, are given at the 1 bar atmospheric level. 

Chapter 5 by Lisa Kaltenegger examines our present knowledge of exoplanet atmospheres and future observational prospects, within the context of searching for biomarkers of extraterrestrial life. This is done on the assumption that physicochemical and biochemical characteristics of our only known life and their effects on planetary atmospheres constitute the search model. She first lists the exoplanet physical and chemical properties that have been measured so far by observational... 

Because radiation tends to be modified when it interacts with matter, it is possible to infer certain physical properties of planetary atmospheres and surfaces by studying their reflected and emitted radiation. Although these modifications are macroscopic in nature (they are manifested over an extended volume), their origins are contained in the processes of absorption, scattering, and emission of radiant energy on a microscopic scale. A quantitative assessment of the relation between these interactions and the resulting radiation field is known as the theory of radiative transfer. It is the purpose of this section to develop the equation central to this theory. 

The preceding chapter demonstrates how the basic thermal, compositional, and cloud structures of planetary atmospheres can be inferred from infrared measurements. Some information on surface properties is also available. So far, however, there has been no discussion of how underlying physical processes cause these structures to develop and evolve. That is the purpose of this chapter. 

Due to the crucial role of aqueous chemistry in a variety of environmental, biological, and industrial processes, experimental studies of ice remain an important field of modern physical chemistry. Examples of applied areas, which require knowledge of the physics and chemistry of various solid forms of water, include atmospheric chemistry and climate change, soil chemistry, planetary and interstellar chemistry, cryopreservation, and research into alternative energy sources. Furthermore, ice and water are uniquely accessible to computational modelling, due to the availability of extensive information on the intermolecular interactions in water-containing systems. Therefore, ice is often considered to be a model system for studies of fundamental properties of condensed molecular phases. 

The current status of exoplanet characterization shows a surprisingly diverse set of giant planets. For a subset of these, some properties have been measured or inferred using radial velocity (RV) measurements, micro-lensing, transits, and astrometry. These observations have yielded measurements of planetary mass, orbital elements, planetary radii and during the last few years, physical and chemical characteristics of the upper atmosphere of some of the transiting planets. Specifically, observations of transits, that provide a radius estimate for the planet, combined with RV information, that provide a mass estimate for the planet, have provided estimates of the density of... 

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