On Algebraic Perturbations in the Atmospheric Boundary Layer
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A simple model for the development of submesoscale perturbations in the atmospheric boundary layer (ABL) is proposed. The growth of perturbations is associated with the shear algebraic instability of the wind velocity profile in the ABL. Seeking optimum values of such perturbations (streaks) allows one to solve the problem of estimating their scales, which turn out to be about 100–200 m vertically and 300–600 m horizontally. Similar scales are also revealed for experimental data on the structure of the wind field in the lower part of the ABL; the data were obtained in 2017 and 2018 in summer at the Tsimlyansk Scientific Station of the Obukhov Institute of Atmospheric Physics during acoustic sounding of the atmosphere with a high-resolution three-component Doppler minisodar.
Keywords:atmospheric boundary layer algebraic growth optimal perturbations streaks
We are grateful to M.V. Kalashnik, V.F. Kramar, and M.A. Kallistratova for their interest in the work and useful discussions, as well as to a reviewer for critical and constructive notes which allowed us to improve the exposition of the results of this investigation.
The investigations were supported by the Russian Foundation for Basic Research, project nos. 17-05-01116 and 18-35-00600, as well as by major projects of the Presidium of the Russian Academy of Sciences, KP19-259/P1 and KP19-278/P20.
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