Study of Explosive and Nonexplosive Cyclogenesis During FGGE(First Global Garp Experiment)
Abstract
The purpose of this thesis is to analyze and evaluate explosive cyclogenesis during the winter of the First Global GARP Experiment (January to February 1979). Explosive cyclogenesis is defined as a decrease in the sea-level pressure at the rate of one mb per hour for a period of 12 h up to 24 h. The European Centre for Medium-range Weather Forecasts (ECMWF) provided the revised analyses for evaluation and comparison of important cyclone properties in a sample of 13 explosive developing cases and eight nonexplosive cases. The specific parameters being examined include the static stability, low-level absolute vorticity, vorticity advection, eddy and mean modes of the vorticity transport, upper-level divergence, kinematic vertical velocities and the strength of the low-level baroclinity. These parameters are compared at the initial, 12 and 24 hour time periods as well as the overall 24 hour average. The statistical relationships and magnitudes of these terms indicate the most significant physical mechanisms in explosive cyclone development compared to the nonexplosive storm group. The important outcome of these results is that the kinematic vertical velocity and the upper-level forcing mechanisms are statistically separable. The large values for the upper-level process suggest that the upper troposheric wave influence is most likely producing the stronger vertical motions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1988
- Accession Number
- ADA206521
Entities
People
- Eric J. Wright
Organizations
- Naval Postgraduate School