Vertical Cross Sections
In previous chapters the diagnosis of a cyclogenesis was clearly made and supported by the numerical parameters in model fields on pressure surfaces. To gain more insight in the vertical structure of the PV-anomalies and the vertical structure of the frontal system, the use of cross sections can be very helpful.
Vertical Cross Sections (VCS) trough the frontal system
In the next chapter several numerical parameters in the vertical cross sections are discussed for the significant development phases of the cyclone.
|
17 Oct 2004: 06UTC |
|
17 Oct 2004: 18UTC |
|
18 Oct 2004: 06UTC |
Summary of the investigations in this chapter
With use of vertical cross sections the vertical structure of the PV-anomaly became very clear: In time we detected a downward protrusion of stratospheric air. As the cyclogenesis proces goes on, also in the lower levels a PV anomaly can be seen. The two anomalies seems to interact and giving reason to the strong development. The stationary character of the system can be explained by the vorticity fields. In a nearly East-West cross section, the PVA maximum is located almost in the same area as the vorticity maximum. Therefore eastward propagation of the trough is hardly possible. So, the PVA maximum is indicating not the movement of the trough, but the deepening of the trough. In previous chapter this idea was already supported by the geopotential height fields at 300 and 500 hPa.