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Simulation of the observed evening transition and nocturnal boundary layers: Large‐eddy simulation
Author(s) -
Beare R. J.,
Edwards J. M.,
Lapworth A. J.
Publication year - 2006
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1256/qj.05.64
Subject(s) - evening , boundary layer , parametrization (atmospheric modeling) , context (archaeology) , meteorology , large eddy simulation , morning , jet (fluid) , wind speed , atmospheric sciences , turbulence , mechanics , physics , environmental science , climatology , geology , optics , astronomy , paleontology , radiative transfer
Large‐eddy simulations are performed of two observed cases of evening transition boundary layers over land. Although generally similar to the observations, the simulations have a poor match to the ageostrophic wind above the boundary layer and overestimate the nocturnal 4 m wind speed. For one case, the nocturnal phase is also simulated using a close match to observations in the early evening, reproducing well the early morning boundary layer and jet. This is achieved with a moderate resolution (5 m) and also demonstrates the importance of a good initial wind state. In a numerical weather‐prediction context, these findings motivate improved wind profile observations around transition, and a better representation of the ageostrophic wind by the boundary‐layer parametrization. Copyright © 2006 Crown copyright