Weather Regimes and Preferred Transition Paths In a Three-Level . . .

• Main Authors: D. Kondrashov, K. Ide, M. Ghil
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2003
• Subjects: Arctic; North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.8.4770; http://www.atmos.ucla.edu/tcd/PREPRINTS/KGIpaper.pdf

Multiple flow regimes are reexamined in a global, three-level, quasi-geostrophic model with realistic topography in spherical geometry. This QG3 model, using a T21 triangular truncation in the horizontal, has a fairly realistic climatology for Northern Hemisphere winter, and exhibits multiple regimes that resemble those found in atmospheric observations. Four regimes are robust to changes in the classification method, k-means vs. mixture modeling, and its parameters. These regimes correspond roughly to opposite phases of the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO), respectively. The Markov