Comment on “Greenhouse cooling of the upper atmosphere”



The vertical distribution of temperature affects most of the atmosphere's wave-like phenomena and in particular, tides. In “Greenhouse Cooling of the Upper Atmosphere,” which appeared in the February 23, 1993, Eos, R. G. Roble's Figure 1 shows the present profile of temperature versus height and one predicted for the end of the next century from accumulation of greenhouse gases. The predicted profile shows about 10°C warming of the troposphere and cooling of the stratosphere and mesosphere, with maximum cooling, about −20°C, at the stratopause. The implications of this prediction for semidiurnal gravitational tides at the Earth's surface can be assessed qualitatively from dependence of tidal pressure on the two principal vertical modes of response to tidal excitation, namely the Lamb and Pekeris modes.