Surface wind variability on spatial scales from 1 to 1000 km observed during TOGA COARE

Near-surface wind spectra are considered from three very different data sources, covering a range of spatial scales from 10⁰ to 10³ km. The data were observed during the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment intensive observation period spanning November 1992 to February 1993. Spectra are examined from low-resolution yet spatially and temporally complete National Centers for Environmental Prediction reanalysis wind fields, moderate resolution satellite-based ERS-1 scatterometer winds, and high-resolution aircraft observations from the National Center for Atmospheric Research Electra. Combined spectra (kinetic energy vs wavenumber k) from these data demonstrate a power-law relation over the entire range in spatial scales, with a best-fit slope very near k^-5/3. Energy spectra for subsets of the data support spectral slopes of k^-5/3 and k^-2, but there is little evidence for a slope of k^-3.