Ocean Dynamics 
Ô Springer 
Number 
12°E 16°E 20°E 24°E 28°E 
SSS on 20140613+01 h 
Min 
12°E 16°E 20°E 24°E 28°E 
Max 
63°N 
60°N 
57°N 
54° N 
12°E 16°E 20°E 24°E 28°E 
Stdev 
Mean 
Median 
63°N 
60°N 
57°N 
54°N 
63°N 
60°N 
57°N 
54° N 
12°E 16°E 20°E 24°E 28°E 12°E 16°E 20°E 24°E 28°E 12°E 16°E 20°E 24°E 28°E 
Fig. 3 Example showing the number of forecasts per grid cell (a), ensemble minimum (b) and ensemble maximum (c), standard deviation (d), MME 
mean (e), and MME median (f) of SSS 01-h forecast in the Baltic Sea 
and differences in tidal phase in the models. Thus, high 
values of angles might give the wrong impression of very 
strong varying forecasts. 
This relationship between the patterns of the statistics dur 
ing the storm event is displayed on most days in the North Sea 
and the Baltic Sea, also when the currents are generally lower. 
High SSC occur in the Skagerrak and Kattegat and are often 
connected to high standard deviation between the forecasts in 
this region. Due to the higher resolution of the forecasts in the 
Baltic Sea, patterns are more detailed than in the North Sea. 
However, to make a qualitative comparison between the fore 
casts for the narrow Transition Area, even higher resolution of 
model grids is needed for this region. 
3.3 Water transport 
Owing to differing grid extensions and orientations, not every 
model delivers transport data at each transect. However, the 
major central part of the North Sea is covered by six models. 
Daily maps are produced separately for the North Sea and the 
Baltic Sea (Fig. 7). Since water transports in the Baltic Sea are 
typically smaller than in the North Sea, it is important to note 
that the scale factor of the arrows is different in both maps and 
thus cannot be directly compared. If the ensemble mean is 
close to 0, the CV index (see Sect. 2.2.3) is in a critical area 
and should be handled carefully. A CV index greater than 3 
appears mostly when the ensemble mean is close to 0 either 
due to very low transports or due to opposed transport direc 
tion. Temporarily, there occur major product disagreements in 
some regions which are further evaluated in Sect. 4.4. But, 
mostly, there seems to be a stable agreement between the 
products; seasonal differences like higher transports in winter 
and lower transports in summer are reflected by most of the 
products. The mean circulation patterns in North Sea and 
Baltic Sea are generally well represented by the water trans 
ports, i.e., major transport through the English Channel,