Department of Meteorology. North Atlantic eddy-driven jet and circulation patterns: Structures, preferred paths and transitions. Abdel Hannachi. Tim Woollings & Brian Hoskins. 1. Background 2. Jet positions and circulation patterns 3. Preferred paths and transitions 4. Summary. Background.
North Atlantic eddy-driven jet and circulation patterns: Structures, preferred paths and transitions
Tim Woollings & Brian Hoskins
2. Jet positions and circulation patterns
3. Preferred paths and transitions
et al (2009)
Rennert & Wallace,
J. Clim, 2009
Non-Gaussian grid points
(1%) of NH winter SLP
NH winter MSLP skewness
et al (2009)
the jet latitude with time
(Woollings et al. 2010, QJ)
Jet positions and circulation regimes associated with jet stream.
Jet preferred locations
PDF of North Atlantic jet
latitude (three modes)
Z500 anomaly pattern associated with the
preferred jet locations
Circulation regimes associated with jet stream.
number of components
Scatter plot within EOFs associated with jet stream.
1 and 2 and the three component mixture model
(colours refer to latitude anomalies)
Preferred paths and transition probabilities associated with jet stream.
We get the most persistent regimes
We start getting preferred paths
Between regimes in state space
Preferred path towards GB regime (southern jet position) associated with jet stream.
Sequence of the fourth
regime centroid in a
mixture with K=4, and
delay parameter of 40
Z500, contour interval 10 m
B = associated with jet stream.north - south
Transition path (GB) and wave-breaking
Blocking index: reversal in on PV2 surface
Mean state of blocking index (delay space) associated with transition path toward WB
Computed using the mixture model:
Probability model: no need to classify each datum