A radiative-conductive model is constructed to study short-term effects of various carbon dioxide concentrations on the atmospheric boundary layer for different seasons. The distribution of the exchange coefficient is modeled with the aid of the KEYPS formula. Infrared radiation calculations are carried out by means of the emissivity method and by assuming that water vapor and carbon dioxide are the only radiatively active gases. Global radiation is computed by specification of Linke's turbidity factor.
It is found that doubling the carbon dioxide concentration increases the temperature near the ground by approximately one-half of one degree if clouds are absent. A sevenfold increase of the present normal carbon dioxide concentration increases the temperature near the ground by approximately one degree. Temperature profiles resulting from presently observed carbon dioxide concentration and convective cloudiness of 50% or less are compared with those resulting from doubled carbon dioxide concentrations and the same amounts of cloud cover. Again, it is found that a doubling of carbon dioxide increases the temperature in the lower boundary layer by about one-half of one degree.
The present results are obtained on the basis of fixed temperature boundary conditions as contrasted to the study ofManabe andWetherald (1967). Howeve, the conclusions are not addressed to global climate change, but to the distribution of the temperature of the air layer near the ground.