List of Figures 
210 
Nordseezustand 2003 
Fig. 3-8: As Fig. 3-7, but for 2002 56 
Fig. 3-9: Seasonal percent frequency distributions of observed wind speed and direction at 
>UFS DB< in 2003 59 
Fig. 3-10: Seasonal percent frequency distributions of wave height and direction at position 
>UFS DB< in 2003 (WAM-Model, DWD). Note log 2 -scaling of horizontal axis (k) 60 
Fig. 3-11: Seasonal percent frequency distributions of wave height and direction at position 
»Entenschnabel« in 2003 (WAM-Model, DWD). Note log 2 -scaling of horizontal axis (k).... 63 
Fig. 3-12: Fligh-water levels at Cuxhaven in 2003 (rel. to ordnance datum) together with 1971 - 
2000 base period monthly means and 95%-band as well as intramonthy 90%-limits 66 
Fig. 3-13: Fligh-water levels at Cuxhaven and NW-componentofthe »North Sea Wind« (2003). 
66 
Fig. 3-14: Monthly SSTanomalies in 2003 as departures from 1971 - 1993 climatology. Contour 
interval is 0.5 K. 69 
Fig. 3-15: Seasonal cycle of areal mean weekly SST of the North Sea from December2002 throu 
gh November2003 and ensemble of corresponding cycles since 1968. Size of monthly clima 
te bullets (radius) gives interannual standard deviation for base period 1971 - 1993 70 
Fig. 3-16: Seasonal cycle 2003 of monthly mean SST at Flelgoland Reede together with 1971 - 
2000 base period monthly means and 95%-band (climatology ±1.96 standard deviations). 
70 
Fig. 3-17: Sketch of annual temperature swing (mean and seasonal extremes) in continental 
and maritime climates (CON & MAR) as well as in cool and warm mishmash-climates (MMC/ 
cold-regime & MMW/ warm-regime) 77 
Fig. 3-18: Serial mon thly North Sea SST anomalies (base period 1971-1993). Filled circles indica 
te anomalies beyond ± 1.96 s, green curve is a low-pass smoother of width 24 month. Regime 
lengths and boundaries are given through a step function (cf. text) 72 
Fig. 3-19: Seasonal percent frequency distributions of geostrophic wind speed and direction 
across the North Sea for warm (1991 - 2000, top) and cold SST regime (1978 - 1987, middle). 
Left panel is for winter (JFM=January - March), right panel for summer (JAS = July -Septem 
ber), bottom panel shows seasonal regime difference. The 0.5 % contour (stippled) encloses 
about 98 % of all samples (900 for JFM, 920 for JAS). Cumulative differences within ± 0.5 % 
envelopes (bottom) amount to ±18% for JFM and ±15% for JAS. Velocity is expressed in 
units of hPa per 10° latitude at 55°N, 1 unit being equivalent to 1.2 Kt or 0.62 m/s 75 
Fig. 3-20: Temperature stratification (°C) in summer2003 (RV Gauss, Reise #405) 78 
Fig. 3-21: Temperature stratification (°C) in 2003 at MARNET stations >Deutsche Bucht<, >Ems< 
and >NSB Ik Sensor depths: 3,6, 10,15,20,25,30,35 m 79 
Fig. 3-22: Geographical distribution of heat content per unit volume in August 2003 and July 
2002 81 
Fig. 3-23: Fleat content per unit water column along 58° N in August 2003, model vs. observati 
ons 82 
Fig. 3-24: Seasonal evolution of North Sea heat content in 2002 and 2003 (model data) toge 
ther with 1971 - 2000 base period monthly means and 95%-band (climatology ±1.96 stan 
dard deviations). Obs = Gauss #385 (Jui 2002), Gauss #405 (Aug 2003) 83 
Fig. 3-25: Monthly mean North Sea heat content (xlO 21 J) with anomalies and percentiles (%), 
and NAO-Index (Loewe and Koslowski 1998). Low-pass filter width 6 month. Color-steps for 
percentiles: 1,5,10,25,50,75,90,95,99% 84 
Fig. 3-26: North Sea heat content versus SST (annual means) 85 
Fig. 3-27: North Sea heat content (annual means) versus winter NAO-Index (Dec-Jan-Feb, Loe 
we and Koslowski 1998) 85