A Study of the Radiative Dissipation of Planetary Waves Using Satellite Data

Abstract

Radiative dissipation coefficients for the observed, large-scale temperature waves in the middle atmosphere are presented and discussed. These have been calculated using LIMS measurements of the temperature, ozone, and water vapor distributions in a broadband radiative heating model. The total dissipation rate is determined by contributions due to thermal emission by the three gases considered and the absorption of solar radiation by ozone, which is important in the high stratosphere. The relative contribution of each gas to the total dissipation coefficient is discussed; this scales approximately with the contribution to the radiative balance of the atmosphere. In the winter hemisphere, the results are comparable with linearized estimates of the radiative dissipation coefficient, consistent with the deep vertical structure of the waves. Tropical dissipation rates are markedly different; in the middle and high stratosphere the analytical results of Fels are confirmed for the observed waves. Some evidence is tentatively presented for wave amplification by radiative processes in the low stratosphere, arising from absorption by the 9.6-?m bands of ozone.