I 
General_summary aus: International Council for the 
Exploration of the Sea: Flushing Times of the North Sea. 
Cooperative Res. Rep. 123, Kopenhagen 1983 
The present report deals with an attempt to establish 
the possibility of using the concept of "flushing time" 
in a practical situation of the North Sea, The exercise 
should be looked upon as a basis for further studies, 
Especially in connection with research of marine pollution 
this may be relevant. 
In that connection data given here might also be used in 
practical pollution problems. At the present stage, how- 
ever, this might easily lead to mis-use of data that are 
presented for another purpose, And although in the follow- 
ing some of the considerations given are of a practical 
nature in order to illustrate the significance of the 
concepts, the aims of the report are primarily to con- 
tribute to scientific work, and results presented here 
will only become more and more firm as they are supported 
by further scientific evidence. 
Transport processes in the sea, involving both advection 
and turbulent diffusion largely determine the distribution 
of the concentration of dissolved substances, Studies of 
marine pollution require a description of these transport 
processes and an understanding of the mechanisms involved, 
Also for various other studies the transport processes in 
the sea are of importance, 
The study of dynamical oceanography has resulted in the 
mathematical modeling of transport processes, Although 
each model is only an imperfect replica of the reality, 
the mathematical models have evolved into a strong tool 
for the above-mentioned studies. In this report A.M. Davies 
deals with such models in section 19.