296 
List of Figures 
List of Figures 
Atmospheric Physics 
Figure 2-1: Sea level pressure (hPa) for the gale “Kerstin“ of March, 31 2010 together 
with grid positions of weather-typing scheme and classification (Cyclonic/Gale). ... 42 
Figure 2-2: Percent frequencies of reduced weather types for 2008 (blue) and 2009 (red) 
along with empirical distributions for 1971-2000 (stacked columns). Percentile range 
Min to Max, internal interval limits at 10, 25, 50 (median, continuous stepline), 75 and 
90% 52 
Figure 2-3: As Figure 2-2, except for monthly absolute frequencies (days) 53 
Figure 2-4: As Figure 2-2, except for 2010 and 2011. ^4 
Figure 2-5: As Figure 2-2, except for monthly absolute frequencies (days) in 2010 and 
2011 55 
Figure 2-6: Weather-type transitions, annual climatology. The arc length of a ring section 
reflects the frequency f in days of weather type X (marginal sum of countmatrix ф in 
Table 2-19). The segments within section X depict stacked frequencies of transitions 
Y*X-X (column entries); they are colored after the preceding weather type and 
given in ascending order; the leftover portion of section X is associated with self 
transitions Y—X — X. Transitions X— Y*X (row entries), colored after the succeeding 
weather type, are identified by the sockets of Bézier ribbons. The ribbons have color 
X, if f(X — Y) > f(Y X), otherwise color Y. The figure was created with the software 
package Circos (KRZYWINSKI et al. 2009) 57 
Figure 2-7: Same as Figure 2-6, except for 2008 and 2009 59 
Figure 2-8: As Figure 2-6, except for 2010 and 2011 60 
Figure 2-9: Seasonal sea level pressure distributions (SLP, hPa). Left: NCEP/NCAR cli 
matology (1971-2000). Middle: 2008, SLP & SLP anomalies (colored, contour spa 
cing 1 hPa). Right: 2009, ... Red: Distribution type (SLP or SLP/SLPA) and season 
(JFM, AMJ, ... - winter, spring ...) 61 
Figure 2-10: As Figure 2-9, except for 2010 and 2011 62 
Figure 2-11: Monthly sea level pressure distributions (SLP, hPa) in 2008 together with 
departures from the NCEP/NCAR climatology for 1971-2000 (SLPA, colored, con 
tourspacing 1 hPa). Red: Distribution type (SLP/SLPA) and month (J, F,... - January, 
February...) 63 
Figure 2-12: As Figure 2-11, except for 2009 64 
Figure 2-13: As Figure 2-11, except for 2010 65 
Figure 2-14: As Figure 2-11, except for 2011 66 
Figure 2-15: Seasonal 50% probability ellipses for the „North Sea Wind“ (1 - win 
ter - JFM, 2 - spring, etc.); top: 2008, bottom: 2009 67 
Figure 2-16: As Figure 2-15, except for 2010 and 2011 68 
Figure 2-17: Progressive daily vectors of the “North Sea Wind’’ with ensemble and cli- 
matology. Markers indicate the first day in a month, years final points of ensemble 
members. All trajectories start at 1 -(0,0), and proceed by adding consecutive, daily 
wind vectors. Dividing the along-path length of a trajectory and the linear distance 
between any two markers by the associated time interval in days yields the scalar 
wind velocity and the vectorial wind speed in m/s for that period 71 
Figure 2-18: As Figure 2-17, except for 2010 and 2011 72