In:
Atmosphere, MDPI AG, Vol. 13, No. 10 ( 2022-09-25), p. 1567-
Abstract:
As wind shear increases, the quasi-two-dimensional structure of flows becomes more significant in the convective boundary layer (CBL), indicating that wind shear plays an essential role in the variation of the field of atmospheric flow. Therefore, sensitive numerical experiments based on Large Eddy Simulation (LES) techniques were conducted to comprehensively investigate the effects of wind shear on the spatial variations in the velocity and potential temperature (θ) horizontal fields. Under the constant surface heat flux condition, the main findings are summarized. Firstly, in the CBL, the variances of the streamwise velocity (u), cross-stream velocity (v), and θ enhance as wind shear increases, whereas the variance of vertical velocity (w) is insensitive to wind shear. Secondly, in the CBL, with increasing wind shear, low-wavenumber Power Spectrum Densities (PSDs) of u, v, w, and θ increase significantly, suggesting that the increasing wind shear always enhances the large-scale motions of the atmosphere (i.e., low-wavenumber PSD). Therefore, it is more likely that some mesoscale weather processes will be triggered. Thirdly, generally, in the high-wavenumber range, with increasing wind shear, the PSDs of u, v, and θ increase slightly, whereas the PSD of w decreases slightly. This study provides a new perspective for understanding the role of wind shear in the spatial variations of the horizontal fields of meteorological elements under the same conditions of surface heat flux.
Type of Medium:
Online Resource
ISSN:
2073-4433
DOI:
10.3390/atmos13101567
Language:
English
Publisher:
MDPI AG
Publication Date:
2022
detail.hit.zdb_id:
2605928-9
SSG:
23
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