Open AccessOrographic cyclogenesis in a saturated atmosphere and intense precipitation: baroclinic modal solutions under the joint action of localized mountains and humidity
Author(s) -
Roberto Benzi,
Maurizio Fantini,
Roberto Mantovani,
Antonio Speranza
Publication year - 1997
Publication title -
annals of geophysics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.394
H-Index - 60
eISSN - 2037-416X
pISSN - 1593-5213
DOI - 10.4401/ag-3834
Subject(s) - cyclogenesis , baroclinity , orographic lift , tropical cyclogenesis , atmosphere (unit) , climatology , cyclone (programming language) , atmospheric sciences , precipitation , orography , environmental science , geology , meteorology , physics , field programmable gate array , computer science , computer hardware
In this paper we analyse the nature of orographic cyclogenesis in a saturated atmosphere by means of a simplified model based on the analysis of linear modal solutions.The space structure of fastest growing modal solutions suggests that three different scales of axtratropical atmospheric motion may simultaneously be activated in a single, growing, unstable mode: the orographic modulation of growing baroclinic modes extending, as we know from the classical modal theory of orographic cyclogenesis, from the scale typical of the primary, extra-tropical cyclone to the scale of the secondary, orographic cyclone, is also characterized by the (smaller) scale associated with strong ascending motion in a saturated atmosphere. Since ascending motion can be associated with intense precipitation, this result is important in view of its potential consequences both on the ability to achieve a good forecast of intense precipitation events in the Mediterranean and on the refinement of the theory of orographic cyclogenesis