Measurements of velocity and temperature fluctuations were made over a period including a solar eclipse of 80% totality to determine the response of surface layer to the change in ground heat flux. The response of the rms velocity fluctuation lags behind that of the rms temperature fluctuation by about 20 min. Although the velocity spectrum exhibits a good inertial subrange for the whole period of observation, the inertial subrange in the temperature spectrum disappears shortly after the start of the eclipse. It is found that during the eclipse the surface layer turbulence approximately follows a continuum of equilibrium states in response to stability changes brought about by the change in surface heat flux.