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A two‐dimensional numerical study of horizontal roll vortices in the neutral atmospheric boundary layer
Author(s) -
Mason P. J.,
Sykes R. I.
Publication year - 1980
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 - 10.1002/qj.49710644808
Subject(s) - geostrophic wind , eddy , turbulence , buoyancy , vortex , planetary boundary layer , mechanics , boundary layer , physics , atmospheric sciences , mixing (physics) , atmosphere (unit) , scale (ratio) , meteorology , geology , quantum mechanics
The dynamics of large‐scale, horizontal roll vortices in the neutral planetary boundary layer are investigated by means of a two‐dimensional numerical model. The rolls are assumed to be two‐dimensional and are calculated explicitly, while small‐scale turbulence is parametrized by a mixing‐length hypothesis. Although buoyancy effects are never negligible in the atmosphere, the assumptions of the turbulence modelling are supported by atmospheric observations of large eddies which are highly elongated in a direction close to that of the geostrophic wind, together with the observed partitioning of turbulence energy between the large eddies and a distinctly smaller scale. The results indicate a strong sensitivity to the roll orientation, and also the presence of a slow variation on the Coriolis timescale.