10 
BSH 
Ozeanographischer Zustandsbericht 
are due in part to biological production and remineralization, respectively. Evidence for these 
opposing biological processes is also found in vertical profiles of oxygen saturation along 
latitudinal transects. In the gross, nutrient concentrations were close to long-term means for 
the period 1984-2000. Generally, highest concentrations were observed in the German Bight. 
German Bight 
The oceanographic state of the German Bight is estimated from local observations and 
model data, which are the more representative of this sea area the coarser the averaging 
period. An exception is the circulation statistics presented here, which is based on a 
subjective classification of daily near-surface current fields as produced by the BSH model. 
Also in 2002, cyclonic circulation was the most frequent pattern, at about 40%. The most 
notable difference as compared to previous years consisted in a prolonged stable phase of 
this circulation type in January and February as a result of contemporaneous vigorous 
westerly winds (NAO + ). 
Wind and wave conditions are documented by wind measurements at light-vessel Deutsche 
Bucht, wave data from the DWD (Deutscher Wetterdienst) model at the same position, as 
well as wave measurements near Helgoland. The distributions of wind and wave directions 
closely resembled one another and, in particular, were bimodal. The wind distribution 
showed a broad maximum extending from S to W, and a sharper, narrow maximum for 
easterly winds (ENE to ESE). Higher and extreme wind speeds up to 25 m/s were recorded 
at wind directions between SW and NW. The highest waves reached 7 to 8 m and were 
observed to roll in from the same directions. 
Sea surface temperature (SST) and salinity (SSS) are assessed from time series at Helgo 
land Roads. 2002 is the 2 nd warmest year on record dating back to 1873. The annual mean 
SST of 11.0 °C is in exact accord with the annual mean North Sea SST. Moreover, both SST 
series are in excellent agreement about alternating cold and warm regimes in their common 
space of time (1968-2002). It thus appears safe to say that the contemporary warm phase 
that commenced in 1989 is the longest and most intense in 130 years for both Helgoland 
Roads and the entire North Sea. The statistical dependence of SST on the NAO is non 
stationary and not detectable outside the winter half-year. 
Continental runoff rates significantly exceeding long-term means occurred not only since 
August but also - prematurely - in late winter 2001/2002. Hence, salinities at Helgoland 
Roads were anomalously low in fall and winter and above normal during the rest of the year. 
As a result, the phase advance in 2002 features a six month shift vis-à-vis the climatological 
annual cycle. This phase shift appears typical of the current saline regime that has prevailed 
since around 1989. At least since the 1960s, saline and fresh regimes appear to have 
corresponded to the observed warm and cold SST regimes. Possibly this holds true for the 
entire North Sea. 
Nutrient concentrations from automatic analyzers at MARNET station Deutsche Bucht largely 
cover the 2002 annual cycle. Exceedingly large precipitation and runoff rates caused steep 
jumps in concentrations in February that correlate inversely with simultaneous salinity 
measurements. The impacts of the Elbe river’s flood of the century in August were next to 
untraceable from the data records because of a several-week equipment failure from Sep 
tember 17. In addition, SSS data for the better part of the second half of the year were either 
discarded on account of biofouling or still appear compromised for this reason or others. 
The final cause of the Elbe-flood was a Vb or backdoor depression that, after a detour across 
the Mediterranean, traversed the Eastern Alps and became stationary over eastern Germany 
on August 12. Gale-force northwesterly winds in the rear of this vast depression caused a 
doubling in precipitation due to orographic convection along the windward side of the high 
lands. The flood showed in a significant drop in salinity on September 4 at Helgoland Roads. 
A secondary depression in salinity on September 20 signifies the return of diluted waters 
from the north on account of changing wind and current patterns in between both datings.