The temperature dependence of collision-induced state changes

Parmenter, C. S.; Seaver, Mark

doi:10.1016/0009-2614(79)85162-3

Cited by 22 publications

(1 citation statement)

References 10 publications

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“…H, C1, and F quench CO 2 rapidly compared to noble gases, such as He, Ne, and Xe (Chu etal., 1983;Flynn and Weston, 1986). The large cross sections and the negative temperature dependences at low collision energies for such systems have been ascribed to the formation of long-lived collision complexes in the presence of strong attractive chemical, hydrogen bonding or Van der Waals forces (Ewing, 1978;Linet al, 1979;Parmenter and Seaver, 1979;Gordon, 1981 ;McClelland et al, 1979). The lifetime of a collision complex is longer at low collision energies, and the longer-lived the collision complex, the greater the probability that the energy in the vibrational mode may flow into the weak bond of the complex and cause its dissociation.…”

Section: Ir Heating and 15-pm Coolingmentioning

confidence: 99%

Structure, luminosity, and dynamics of the Venus thermosphere

Fox

Bougher

1991

Space Sci Rev

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We review here observations and models related to the chemical and thermal structures, airglow and auroral emissions and dynamics of the Venus thermosphere, and compare empirical models of the neutral densities based in large part on in situ measurements obtained by the Pioneer Venus spacecraft.Observations of the intensities of emissions are important as a diagnostic tool for understanding the chemical and physical processes taking place in the Venus thermosphere. Measurements, ground-based and from rockets, satellites, and spacecraft, and model predictions of atomic, molecular and ionic emissions, are presented and the most important sources are elucidated. Coronas of hot hydrogen and hot oxygen have been observed to surround the terrestrial planets. We discuss the observations of and production mechanisms for the extended exospheres and models for the escape of lighter species from the atmosphere. Over the last decade and a half, models have attempted to explain the unexpectedly cold temperatures in the Venus thermosphere; recently considerable progress has been made, although some controversies remain. We review the history of these models and discuss the heating and cooling mechanisms that are presently considered to be the most important in determining the thermal structure. Finally, we discuss major aspects of the circulation and dynamics of the thermosphere: the sub-solar to anti-solar circulation, superrotation, and turbulent processes.

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