Oort, A. H., and A. Taylor, 1969: On the kinetic energy spectrum near the ground. Monthly Weather Review, 97 (9), 623-636.
Abstract: For six stations in the northeastern United States, the spectrum of horizontal
wind speed was analyzed using 10 yr of 1-min averaged, hourly surface reports.
The fast Fourier transform technique was employed to estimate the spectrum
between 1 cycle/2 hr and 1 cycle/2 yr.
The kinetic energy spectra show two major spikes at periods of 24 hr and
1 yr. However, most of the energy is contained in the traveling cyclones
and anticyclones with periods between 2 and 7 days. The apparent discrepancy
between Van der Hoven's results and our results concerning the existence
of an important diurnal cycle in the kinetic energy can be explained by
Blackadar's theory of the diurnal wind variation with height. Van der Hoven's
spectrum represents conditions near the top of the surface layer, while
our data were taken well within the surface layer. A line-by-line investigation
of the diurnal peak reveals a very sharp line at 2400 hr with two side lobes
3.9 min away from the main line. These side lobes are probably caused by
an annual modulation of the diurnal cycle.
The spectra tentatively corrected for aliasing give some indication of the
existence of a spectral gap between small-scale turbulence and mesoscale
phenomena.