Serial Clustering of Extratropical Cyclones
- 1 August 2006
- journal article
- Published by American Meteorological Society in Monthly Weather Review
- Vol. 134 (8), 2224-2240
- https://doi.org/10.1175/mwr3160.1
Abstract
The clustering in time (seriality) of extratropical cyclones is responsible for large cumulative insured losses in western Europe, though surprisingly little scientific attention has been given to this important property. This study investigates and quantifies the seriality of extratropical cyclones in the Northern Hemisphere using a point-process approach. A possible mechanism for serial clustering is the time-varying effect of the large-scale flow on individual cyclone tracks. Another mechanism is the generation by one “parent” cyclone of one or more “offspring” through secondary cyclogenesis. A long cyclone-track database was constructed for extended October–March winters from 1950 to 2003 using 6-h analyses of 850-mb relative vorticity derived from the NCEP–NCAR reanalysis. A dispersion statistic based on the variance-to-mean ratio of monthly cyclone counts was used as a measure of clustering. It reveals extensive regions of statistically significant clustering in the European exit region of the North Atlantic storm track and over the central North Pacific. Monthly cyclone counts were regressed on time-varying teleconnection indices with a log-linear Poisson model. Five independent teleconnection patterns were found to be significant factors over Europe: the North Atlantic Oscillation (NAO), the east Atlantic pattern, the Scandinavian pattern, the east Atlantic–western Russian pattern, and the polar–Eurasian pattern. The NAO alone is not sufficient for explaining the variability of cyclone counts in the North Atlantic region and western Europe. Rate dependence on time-varying teleconnection indices accounts for the variability in monthly cyclone counts, and a cluster process did not need to be invoked.Keywords
This publication has 41 references indexed in Scilit:
- Sensitivity of Feature-Based Analysis Methods of Storm Tracks to the Form of Background Field RemovalMonthly Weather Review, 2003
- Identification of cyclone‐track regimes in the North AtlanticQuarterly Journal of the Royal Meteorological Society, 1997
- On Energy Flux and Group Velocity of Waves in Baroclinic FlowsJournal of the Atmospheric Sciences, 1994
- Frontal Wave Stability during Moist Deformation Frontogenesis. Part II: The Suppression of Nonlinear Wave DevelopmentJournal of the Atmospheric Sciences, 1994
- Frontal Wave Stability during Moist Deformation Frontogenesis. Part I: Linear Wave DynamicsJournal of the Atmospheric Sciences, 1994
- On the Dynamics of a Storm TrackJournal of the Atmospheric Sciences, 1993
- Classification, Seasonality and Persistence of Low-Frequency Atmospheric Circulation PatternsMonthly Weather Review, 1987
- Systematic errors in the behaviour of cyclones in the ECMWF operational modelsTellus A: Dynamic Meteorology and Oceanography, 1985
- REVIEW OF MODERN METEOROLOGY—12. The problem of tropical hurricanesQuarterly Journal of the Royal Meteorological Society, 1954
- THE DYNAMICS OF LONG WAVES IN A BAROCLINIC WESTERLY CURRENTJournal of Meteorology, 1947