Results are presented from experimental lidar studies of fluctuation spectra of the coefficient of backscattering in the atmospheric surface layer. Significant differences are found between the fluctuation spectra of scattering and of wind speed, presumably explained away as the effects of temperature stratification and of convective turbulence. When stratification of the surface layer is stable there appears a "sub-area of buoyancy" (the Boljiano-Monin spectrum) in fluctuation spectra of the coefficient of backscattering.