KLIWAS 
Seite 32 
KLIWAS 
Climatology 
of North Sea 
Fronts 
large wind farms or off-shore structures. The operational use of the new method may 
also help in assuring the so-called Good Environmental Status (GES) as required by 
the European Marine Strategy Framework Directive as well as in the identification of 
vulnerable areas for marine spatial planning (The European Commission, 2010). 
For Future applications there are several EO data sets which can be analysed by 
GRADHIST. The most promising sensor for the greater North Sea area will be the 
SLSTR and OLCI on Sentinel-3 which will provide SST and OC data with a spatial 
resolution of 300 m. First data are expected to be available in 2015. The Group for 
High Resolution SST (GHRSST) provides several ultra-high resolution (UHR, <5km 
resolution) regional SST products, however, up to now they are excluding the North 
Sea area (GHRSST, 2009). The AVHRR SST Pathfinder Project Version 5.2 
reprocessed the entire 1981-2009 archive at the 4 km Global Area Coverage (GAC) 
level, the highest resolution globally achievable. This data is now available, but not 
useful for front detection in the North Sea due to its spatial resolution. However, for 
Version 6 they planned a large collection of High-Resolution Picture Transmission 
(HRPT) and Local Area Coverage (LAC) data collected at stations around the world. 
The HRPT or LAC data at roughly 1.1 km resolution are applicable for the front 
detection and for analysis of the time series (Casey et al. 2010). 
An important analysis to be added in the future is the impact of the local wind field 
on frontal position and gradient strength. The analysis presented in Chapter 5 with a 
mean geostrophic wind field for the whole North Sea area should be repeated for 
selected areas with local wind fields. Especially the RPFs in coastal waters are known 
to be influenced by selected wind directions if they are persisting for a few days to 
allow the fronts to adjust to the wind field. Another aspect not mentioned up to now is 
the influence of changing river run-offs into the North Sea due to changing 
precipitation patterns and volumes over land on RPFs. However, also these changes 
can be detected and monitored by GRADHIST on the basis of the new climatology.