The power distribution between symmetric and anti-symmetric components of the tropical wavenumber-frequency spectrum

Abstract A yet unexplained feature of the tropical wavenumber-frequency spectrum is its parity distributions, i.e., distribution power between meridionally symmetric and anti-symmetric components spectrum. Due to linearity decomposition Fourier analysis, total spectral equals sum contained in each these two components. However, need not be evenly distributed Satellite observations reanalysis data provide ample evidence that biased towards component. Using an intermediate-complexity model idealized moist atmosphere, we find nearly insensitive large-scale forcing, including topography, ocean heat fluxes, land-sea contrast. On other hand, a small-scale (stochastic) forcing has capacity affect at large spatial scales via upscale (inverse) turbulent energy cascade. These results are qualitatively explained by considering effects triad interactions on distribution. According proposed mechanism, any bias or anti-symmetric, leads regardless source variability responsible for onset asymmetry. As this process also associated with generation features Tropics convection, present study demonstrates physical deep-convection