%0 Journal Article
%T Cyclogenesis in the lee of the Atlas Mountains: a factor separation numerical study
%A K. Horvath
%A L. Fita
%A R. Romero
%A B. Ivancan-Picek
%A I. Stiperski
%J Advances in Geosciences (ADGEO)
%D 2006
%I Copernicus Publications
%X The initiation of a deep and severe impact Mediterranean cyclone in the lee of Atlas Mountains is investigated by a series of numerical experiments using the MM5 forecast model. Roles of orography, surface sensible heat flux and an upper-level potential vorticity anomaly are identified using factor separation method. Results of model simulations show that orography blocking is responsible for generation of the low-level shallow vortex in the first phase of lee development. Upper-level potential vorticity is a principal ingredient of this event, responsible for a dominant deepening effect in the later stage of lee formation. Analysis of cyclone paths shows that orography tends to keep the cyclone stationary, while upper-level dynamical factors are crucial for advection of the system to the Mediterranean Sea. The most noteworthy influence of surface sensible heat flux is identified as an afternoon destruction of a surface baroclinic zone and associated weaker cyclogenesis.
%U http://www.adv-geosci.net/7/327/2006/adgeo-7-327-2006.html