Vertical Cross Sections
Vertical cross sections are important tools as they allow a view into the vertical extension of synoptic and mesoscale systems. In this chapter the main aspects of interest is: The physical state of the cloud band in the vertical dimension in respect to a frontal character:- the W-E oriented cloud band in the beginning, the comma tail and later on the frontal cloud band of the synopic-scale cloud spiral under consideration
Vertical Cross Sections (VCS) for the growing cloudspiral
In this chapter, relevant parameters are presented in a vertical cross section for an initial (1st March 2004:06 UTC) and an end stage (2nd March 2004:12 UTC). The main question of interest is if there are frontal characteristics from the very beginning or only later or not at all. To have a common nomenclatur is the system under consideration in the whole case study called “the growing cloud spiral”.
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Cloudspiral: 1st March 2004: 06UTC |
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Cloudspiral: 2nd March 2004: 12UTC |
Summary of the investigations in this chapter
From the Vertical Cross sections it seems to be clear that the development of the first cloud elements of the “growing cloud spiral” do happen under two conditions: 1.) behind a W-E oriented frontal cloud band and 2.) at a N-S oriented bacolinic boundary. This boundary shows in the very beginning a low level frontal zone with CA in low levels and WA only in higher levels but during the development of the cloud spiral the frontal surface becomes more and more vertically extended, the transition of CA to WA happens exactly on top of the frontal surface and the configuration of isentropes as well as all other parameters changes from a typical CT type to a typical occlusion type.
The latter fact is in contradiction with the history of this case which is not the typical history of an occlusion process.