Compilation of Summaries 
28 
System Nordsee 
2 of the Arctic Oscillation Index. Cyclones >Britta< (Nov. 1, 2006), >Franz< (Jan. 12, 
2007), >Orkun< (Mar. 18, 2007), and >Tilo< (Nov. 9, 2007) - the latter pertaining to 
the 2007/08 season - brought about storm surge heights well beyond 200 cm above 
MHW at the German coast. 
Air temperature and radiation (p. 102 sqs.) 
Though based on DWD observations at Norderney, the findings on global radiation 
and air temperature are of supraregional relevance. Departures in 2006 and 2007 
from respective climatological cycles were attributed to atmospheric circulation anom 
alies, related to one another and to surface temperature anomalies of the Northern 
Hemisphere due to NOAA's NCDC. 
The drastic surplus in July 2006 immediately followed by a deficit of conformable size 
in August constitutes one of the most prominent radiation anomalies. Reflecting it 
self in strong diametrical temperature excursions, this dichotomy resulted from steady 
quasistationary high pressure weather (Omega block), which at the end of the month 
was replaced with an equally persistent trough pattern. Another Omega block caused 
the significant radiation surplus of April 2007. 
At 10.6 and 11.0 °C, 2006 and 2007 are the warmest calendar years at Norderney 
during the 40-year period 1971 -2010. These records were put in the shade by the 
extreme warm period, kick-started in July 2006 bye a pan-European heatwave, per 
sisting through June 2007, and reaching a temperature of 12.3 °C, which exceeds the 
climatological mean by as much as 3 K. New records were set by all seasonal tem 
peratures (JAS, OND etc.) such that the entire seasonal cycle proceeded on a level 
elevated about 3 K above normal. The persistence of this warm period resulted from 
an unusual chain of maintaining and reinforcing atmospheric anomalies, viz., a strong 
S-ly flow component from September, an immense frequency of gales from Octo 
ber through March, an extremely enhanced zonal circulation from November through 
January, an excessive radiative surplus in April, and summery weak winds in spring. 
The large-scale impact of atmospheric circulation anomalies shows in the fact that for 
at least 130 years the temperature in the Northern Hemisphere never was as warm 
or warmer than in the next to identical 12-month period from June 2006 through May 
2007. 
Physical Oceanography 
Currents (p. 117 sqs.) 
In the winter of 2006, North Sea surface circulation as derived from monthly current 
fields (model) was characterized by weaker meridional circulation, attributable mainly 
to predominantly southerly winds in the North Sea region in January and March. Due 
to these conditions, the typical seasonal pattern of cyclonic circulation in the entire 
North Sea failed to develop. Also in the spring and summer of 2006, current fields were 
not very stable and hardly showed any supraregional patterns. Strong atmospheric 
zonal circulation developed in autumn/winter of 2006/2007, which was related to one 
of the highest frequencies of storm events in the period of 1948 - 2010. This led to the 
development of a strong, persistent cyclonic circulation pattern in the entire North Sea. 
A reversal of atmospheric circulation in February 2007, with predominantly southerly 
winds, led to a circulation pattern equalling that in March 2006. Whereas, on the one