Estimates of turbulent diffusivities and energy dissipation rates from satellite measurements of spectra of stratospheric refractivity perturbations
- ISSN: 16807316
- DOI: 10.5194/acp-13-12107-2013
Approaches for estimations of effective turbulent diffusion and\nenergetic parameters from characteristics of anisotropic and isotropic\nspectra of perturbations of atmospheric refractivity, density and\ntemperature are developed. The approaches are applied to the data\nobtained with the GOMOS instrument for measurements of stellar\nscintillations on-board the Envisat satellite to estimate turbulent\nThorpe scales, L-T, diffusivities, K, and energy dissipation rates,\nepsilon, in the stratosphere. At low latitudes, effective values are L-T\nsimilar to 1-1.1 m, epsilon similar to (1.8-2.4) x 10(-5) Wkg(-1), and K\nsimilar to (1.2-1.6) x 10(-2) m(2) s(-1) at altitudes of 30-45 km in\nSeptember-November 2004, depending on different assumed values of\nparameters of anisotropic and isotropic spectra. Respective standard\ndeviations of individual values, including all kinds of variability, are\ndelta L-T similar to 0.6-0.7 m, delta epsilon similar to (2.3-3.5) x\n10(-5) Wkg(-1), and delta K similar to (1.7-2.6) x 10(-2) m(2) s(-1).\nThese values correspond to high-resolution balloon measurements of\nturbulent characteristics in the stratosphere, and to previous satellite\nstellar scintillation measurements. Distributions of turbulent\ncharacteristics at altitudes of 30-45 km in low latitudes have maxima at\nlongitudes corresponding to regions of increased gravity wave\ndissipation over locations of stronger convection. Correlations between\nparameters of anisotropic and isotropic spectra are evaluated.