Mesoscale spectral analysis of in situ horizontal and vertical wind measurements at 6 km

As part of the ALOHA/ANLC-93 campaign to investigate atmospheric dynamics, in situ wind measurements collected at 6 km with the gust probe sensor attached to the National Center for Atmospheric Research Electra aircraft were analyzed for 16 flight segments between 61 degrees N and 14 degrees S and between 92 degrees W and 170 degrees W over land and water. Horizontal wavenumber spectra for the vertical wind and both zonal and meridional horizontal-wind components were calculated. The zonal and meridional wavenumber spectra exhibited a decrease in the spectral slope from similar to 1.98+/-0.02 for wavelengths between 2 km and 100 km to similar to 3.18 +/- 0.06 for the longer wavelengths between similar to 100 km and similar to 330 km. The wavenumber spectrum for the vertical wind component showed a -2 power law dependence for wavelengths in excess of 5 km and a generally flat shape at shorter wavelengths. An increase in power at the wavelength of similar to 10 km was detected for the meridional wavenumber spectrum. These results were compared with predictions from two spectral models and with spectral results from other observations.