Nordseezustand 2004 
209 
List of Figures 
Atmospheric Physics 
Fig. 2-1: NAO Index 2004. Ik: Ponta Delgada & Akureyri (Loewe and Koslowski 1998), Ipf6(lk): 
low-pass filtered (6 month), cruuea: Gibraltar & Southwest Island, cpccdb: Amplitude of NAO 
pattern from rotated principal component analysis of700 hPa height anomalies 33 
Fig. 2-2: NAO phase portrait as percent frequency distribution of monthly dynamic NAO states 
since 1879. Contours 0.5, 1, 1.5 and 2% are lines of equal relative state density (i.e. rel. #of 
states per square-bin, 0.6 x 0.6). The sequences of 12 yellow and 12 blue circles (1,2,..., 8, 9, 
O, N, D) show the temporal evolution in 2004 of raw (yellow) and low-pass filtered (6 month, 
blue) monthly mean states, respectively. 34 
Fig. 2-3: Sea level pressure (hPa) for the SW-gale of Oct, 4 2004 together with grid positions of 
weather-typing scheme 36 
Fig. 2-4: Percent frequency distribution of daily circulation states for the period 1971 - 2000 to 
gether with classification criteria 37 
Fig. 2-5: Air circulation around high (A) and low pressure systems (C) 38 
Fig. 2-6: Seasonal frequencies of reduced weather types in 2004 along with percentiles of empir 
ical distributions for 1971 - 2000 (stacked columns); percentile range: 1 - 99, internal interval 
limits at 5,25,50 (median), 75,95% 42 
Fig. 2-7: As Fig. 2-6, except for monthly frequencies 43 
Fig. 2-8: Classified seasonal sea level pressure distributions (hPa). Left: climatology (1971 - 
2000), middle: 2004, right: anomalies; 1 = Winter = January, February, March etc. 46 
Fig. 2-9: Monthly climatology of sea level pressure (hPa), base period 1971 - 2000 47 
Fig. 2-10: Mon thly sea level pressure distributions (hPa) in 2004 49 
Fig. 2-11: Monthly SLP-anomalies (hPa) in 2004 50 
Fig. 2-12: Seasonal 50%-probability ellipses for the »North Sea Wind« (l=winter=JFM, 
2=spring, etc.); top: 2004, bottom: 2003 52 
Fig. 2-13: Progressive daily vectors of the »North Sea Wind« with ensemble and climatology. 
Markers indicate the first day in a month, years final points of ensemble members 54 
Fig. 2-14: Seasonal cycle in 2004 of monthly averaged daily global radiation totals at Norder- 
ney together with intramonthly extremes, 1971 -2000 base period monthly means, and 
95%-band (climatology ± 1.96 standard deviations). 1 Idem 2 is equivalent to a radiation 
flux density of 116 Wm 2 57 
Fig. 2-15: Monthly air surface temperatures at Norderney for 2004 together with 1971 - 2000 
base period means, and 95%-band (dimatology ± 1.96 standard deviations) 58 
Physical Oceanography 
Fig. 3-1: Seasonal surface drculation of the North Sea in 2004 (JFM = January-February-March, 
AMJ ...). Vector mean currents from >BSFIcmod<. Stability (%, colored) is the ratio of vector 
mean current to mean magnitude 65 
Fig. 3-2: Volume transport through the Strait of Dover in 2004 (BSFIcmod); 1 Sv=10 6 m 3 /s... 66 
Fig. 3-3: Volume transport through the Kattegat in 2004 (BSFIcmod); 1 Sv=10 6 m 3 /s 67 
Fig. 3-4: Classification scheme for daily residual currents in the German Bight. 68 
Fig. 3-5: Seasonal frequencies of circulation patterns in the German Bight for2003 and 2004.. 
70