Observational-Numerical Study of Maritime Extratropical Cyclones Using FGGE (First GARP Global Experiment) Data.
Abstract
Analyses of First GARP Global Experiment (FGGE) data have been used to study three cases of maritime extratropical cyclone development. It has been demonstrated that these FGGE analyses are consistent with the observations through synoptic comparisons and satellite interpretations. Quasi-Lagrangian diagnostic budgets of mass, vorticity, angular momentum and heat have been computed in pressure coordinates for observed and model-generated cyclones. The roles of jet streaks and small static stability in the lower troposphere during rapid development of maritime cyclones have been documented. Vertical circulation trends in the mass budget are consistent with the sea-level pressure evolution in each case. Inward transport of vorticity due to the jet streak coincides with the rapid development phase. Vorticity budgets of these maritime cyclones appear to be consistent with earlier studies of continental cyclones. To complement the observational studies, similar diagnostic studies hace been done for numerical simulations of maritime cyclogenesis under straight upper-level flow. These studies demonstrate that similar physical mechanisms are involved in the simulated storms as were found in the FGGE-based studies. Two sets of numerical model predictions from the FGGE analyses were examined for an explosively deepening cyclone over the western North Pacific Ocean. Both models predicted the most rapid deepening phase too early and resulted in too low sea-level pressures.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1985
- Accession Number
- ADA157390
Entities
People
- C. H. Wash
- C. S. Liou
- J. E. Peak
- R. L. Elsberry
Organizations
- Naval Postgraduate School