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The role of the environmental flow in the development of secondary frontal cyclones
Author(s) -
Renfrew Ian A.,
Thorpe Alan J.,
Bishop Craig H.
Publication year - 1997
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.49712354210
Subject(s) - frontogenesis , baroclinity , cyclone (programming language) , cyclogenesis , barotropic fluid , front (military) , geology , diabatic , vorticity , synoptic scale meteorology , shearing (physics) , potential vorticity , meteorology , climatology , mechanics , adiabatic process , physics , mesoscale meteorology , vortex , oceanography , engineering , thermodynamics , geotechnical engineering , field programmable gate array , embedded system
The impact of the environmental flow on the development of secondary frontal cyclones is investigated. Several case‐studies are examined as examples of secondary frontal‐cyclone events observed in the North Atlantic‐western Europe sector. A simple measure of growth is defined to chart their development. The vorticity attribution technique of Bishop is utilized to calculate the action of the large‐scale (environmental) flow on the fronts. In particular the environmental along‐front stretching—shown to be important in theoretical models of frontal instabilities—is calculated. The role of the environmental deformation appears to be crucial: as part of a baroclinic life cycle, stretching deformation acts to build up a front but suppress along‐front waves; if the stretching rate diminishes, barotropic instabilities may then break out. Diagnostics are examined to try to ascertain the growth mechanisms at work in each frontal‐cyclone case. A range of values for the commonly prescribed deformation‐frontogenesis and shearing‐frontogenesis parameters are calculated.