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Modelling non‐linear interactions between wind forced flows in surface frontal regions
Author(s) -
Xing Jiuxing,
Davies Alan M.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl019490
Subject(s) - physics , vorticity , mechanics , geology , shear (geology) , forcing (mathematics) , internal wave , wind shear , inertial frame of reference , computational physics , geophysics , classical mechanics , wind speed , vortex , atmospheric sciences , meteorology , petrology
A non‐linear numerical model with wind forcing at a frequency ω and the inertial frequency f is used to examine the processes giving rise to energy at the (ω + f) and ∣ω − f∣ frequencies in a surface frontal region. Calculations show that vorticity associated with shear in the along frontal jet leads to regions of internal wave propagation (wave frequency > local effective inertial) or trapping. In regions of propagation the non‐linear term involving vertical velocity at frequency ω and vertical shear of lateral velocity at f is the main source of interaction. In trapped regions horizontal current gradients are the main source of interaction. These calculations in part explain the variability found in internal wave energy spectra.