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Evolution of stratosphere–troposphere singular vectors
Author(s) -
de Vries Hylke,
Hooghoudt JanOtto,
Verkley W. T. M.
Publication year - 2011
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.786
Subject(s) - stratosphere , troposphere , potential vorticity , atmospheric sciences , instability , zonal flow (plasma) , rossby wave , environmental science , geostrophic wind , climatology , physics , vorticity , geology , meteorology , mechanics , vortex , plasma , quantum mechanics , tokamak
Abstract Stratospheric conditions affect the tropospheric circulation on a variety of time‐scales. This article addresses two issues in stratosphere–troposphere interaction that are relevant for time‐scales up to a week: the basic growth mechanisms involved and the role of the stratospheric shear. Idealized simulations are conducted of initially stratospheric perturbations that maximize tropospheric total disturbance energy with a lead time of 5 days, assuming linear quasi‐geostrophic dynamics and simplified zonal flow. The evolution is analysed in terms of the basic interactions between three Rossby‐wave components. On the f ‐plane (constant Coriolis parameter), the three‐component analysis is very accurate (the error stays within 1% of vertically integrated total energy) because all available growth mechanisms are captured. Energy growth occurs initially through the Orr mechanism, subsequently through resonance and finally through (normal‐mode) shear instability. On the β ‐plane (Coriolis parameter varying linearly with latitude), errors increase because westward retrogression of the untilting potential vorticity structure is neglected by the three‐component model. Further study reveals that the tropospheric energy growth strongly depends on the value of the stratospheric shear. Copyright © 2011 Royal Meteorological Society