This study used a mid-latitude measurement of diurnal variations in the boundary layer to simulate thermal radiation for a clear sky. The emissivity growth method was used for the absorption by the five major greenhouse gases averaged over 10 cm-1 from line by line calculations. The vertical resolution of the model was 0.6 mb at the ground surface, and gradually increases to 100 mb in the middle troposphere. The importance to the calculated surface and outgoing infrared radiation due to detailed boundary layer structure and diurnal variations is demonstrated. Thus there is a need to carefully consider the near surface atmosphere in construction of radiation models for use in climate studies. ¿ American Geophysical Union 1994