Abstract

It is well recognized that important information on the kinetics (winds) and on the microphysics occurring in planetary atmospheres is contained in intensity profiles of individual atomic and molecular spectral lines. In some cases, unique information is revealed by observing at Doppler-limited spectral resolution, such as the discovery of a naturally occurring CO₂ laser near 75-km altitude on Mars. Other examples include the discovery of the failure of local thermodynamic equilibrium in the first 15 km above the surface of Mars, discovery of strong nonthermal emission from Venus, measurement of Venusian winds from Doppler-limited spectroscopy, the measurement of strong emission cores in C₂H₆ lines on Jupiter, and the measurement of dynamical heating in the polar mesosphere of Mars. All these discoveries were made with ground-based infrared heterodyne spectroscopy, a convenient technique for observing fully resolved line profiles.

© 1985 Optical Society of America