Investigation of non-equilibrium turbulence decay in the atmospheric boundary layer using Doppler lidar measurements
Year: 2024
Type: article
Abstract: . This work concerns analysis of turbulence in the Atmospheric Boundary Layer (ABL) short before and after the sunset. Based on a large set of the Doppler lidar measurements at rural and urban sites we analyze frequency spectra of vertical wind at different heights and show that they increasingly deviate from the −5/3 Kolmogorov’s prediction in the measured low-wavenumber part of the inertial range. We find that before the sunset the integral length scales tend to decrease with time. These findings contrast with a classical model of equilibrium decay of isotropic turbulence, which predicts that the scaling exponent should remain constant and equal to −5/3 and the integral length scale should increase in time. We explain the observations using recent theories of non-equilibrium turbulence. The presence of non-equilibrium suggests that classical parametrization schemes fail to predict turbulence statistics short before the sunset. By comparing the classical and the non-equilibrium models we conclude that the former may underestimate the dissipation rate of turbulence kinetic energy in the initial stages of decay.
Institutions: University of Warsaw, Poznań University of Life Sciences
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,725
OpenAlex ID: W4404858863