Spectra of air pressure fluctuations at the soil surface

Spectra of air pressure and wind were obtained that cover a frequency range from 10−4 to 102 Hz during both day and night with and without a corn crop. The pressure spectra were very similar to those previous workers obtained by different methods under different conditions. The spectral density for pressure decreased with approximately the −6/3 power of frequency for all conditions from about 108 to 10−3 μbar2/Hz over the entire frequency range. The corn crop had no obvious effects on the spectra, but the magnitude of the curves was strongly correlated with surface wind speed, at least for frequencies higher than 10−2.5 Hz.