The inference of atmospheric temperature profiles from ground-based measurements of microwave emission from atmospheric oxygen

It is well known that the microwave thermal emission from the atmosphere as observed at the ground is related to the vertical temperature profile of the atmosphere by a quasi-linear integral equation. We have measured the spectrum of the microwave emission at the zenith in the 5–6-mm band of atmospheric oxygen during December 1967 and August 1968. From these measurements we have obtained temperature profiles for the first 10 km of the troposphere using the statistical estimation technique of Westwater and Strand (1967). We treat the nonlinearity in the integral equation due to the temperature dependence of the oxygen absorption coefficient by iteration. The inferred profiles compare favorably with concurrently obtained radiosonde profiles. The absolute accuracy of the microwave radiometric measurements is 1°–2°K, and the rms agreement between the inferred profiles and concomitant radiosonde profiles is within 2°–5°K.