Absorption and emission in the 8-millimeter region by ozone in the upper atmosphere

Abstract

The absorption of solar radiation and the emission from the atmosphere (effective sky temperature) were measured over the ranges of the millimeter region corresponding to rotational lines of ozone centered at 30,056, 36,025, and 37,830 Mhz. The measurements were made possible by the special development of a frequency-switching radiometer and a gain-compensation technique. The contributions of ozone to atmospheric absorption and emission are evaluated from the solution of the radiative transfer equation on the basis of a line-width function of temperature and pressure and the ARDC 1959 standard atmosphere; the contributions of the water vapor and the oxygen are determined from the theories of Barrett and Chung for H•.O and Meeks for O•. The intensity of the 37,830-Mhz line calculated by Gora was verified in a laboratory study. The width of this line was also found to coincide with the 2340-Mhz value at standard atmospheric conditions as derived by Walshaw from the 9.6-• ozone band. Emission by the 30,056-Mhz line and absorption of the solar radiation by the 37,830-Mhz line were detected, with the line strengths in reasonable agreement with the model calculation. 6137

Passive remote sensing at microwave wavelengths

“…At present five resonances in the terrestrial atmosphere have been observed. Mouw and Silver [35] observed the 36.025-GHz line in absorption against the sun, Caton et al [31] observed the 37.836-GHz line in absorption and the 30.056-GHz line in emission, Barrett et al [36] observed the 23.861-GHz line in emission, and Caton et al [32] observed the 101.737-GHz line in both emission and absorption. For spectral resolution of a few megahertz, the line amplitudes in emission at zenith are generally a few tenths of a degree Kelvin except for the line at 101.737 GHz, which had an amplitude of a few degrees.…”