60
W. PuIs· T. Pohlmann· J. Siindermann
7
Summary and Conclusion
The SPM regime in the southern North Sea is dominated by successions of storm
events and calm periods. For the adequate simulation of this SPM regime, a numerical SPM transport model needs input information about both the current
field and the surface waves. The SPM's temporal variability in the North Sea is
demonstrated by the comparison of two extreme weather situations.
The computed results of the model are compared with the measured SPM data
of the British North Sea Project (NSP). The distribution of mean SPM concentrations in the southern North Sea is not satisfactorily simulated, but the temporal
variation of SPM concentrations is modelled quite well. It is concluded that erosion and deposition of SPM are well simulated by the SPM transport model.
The model results are used to assess the representativity of the NSP data with
regard to its temporal variation. It is concluded that the time frequency of NSP
survey cruises was, in fact, sufficient to give a representative picture of the complete NSP period August 1988-0ctober 1989. The spatial representativity of the
measured NSP data, however, was shown to be imperfect.
Finally a recommendation is given: the planning of future projects with repeated survey cruises around a network of stations may include representativity
tests with a numerical model. Such tests will decrease the risk of getting incomplete results.
Acknowledgements
This study was funded by the participating institutions and the Bundesminister
fur Bildung, Wissenschaft, Forschung und Technologie under grant 03FOlllC.
The authors wish to thank the Bundesamt fur Wehrtechnik und Beschaffung
(Koblenz) and the Amt fUr Wehrgeophysik (Traben-Trarbach) for making available the wave data of the North Sea.
References
AI-RabehAH,Gunay N (1992) On the application of a particle dispersion model. Coastal Eng.,
vol. 17, 195-210
Boudreau BP (1986) Mathematics of tracer mixing in sediments: LSpatially-dependent, diffusive mixing. Amer. J. Sci., vol. 286, 161-198
Dyer KR, Moffat TJ (1998) Fluxes of suspended matter in the East Anglian plume, southern
North Sea. Continental Shelf Research (accepted)
Eisma D, Kalf J (1979) Distribution and particle size of suspended matter in the Southern
Bight of the North Sea and the eastern Channel. Netherlands Journal of Sea Research 13
(2),298-324
Eisma D, Kalf J (1987) Distribution, organic content and particle size of suspended matter in
the North Sea. Netherlands Journal of Sea Research 21 (4),265-285
Eisma D, Irion G (1988) Suspended matter and sediment transport. In: Salomons W, Bayne
BL, Duursma EK, Forstner U (eds) Pollution of the North Sea - An Assessment. SpringerVerlag Berlin Heidelberg New York, 20-35
W. PuIs· T. Pohlmann· J. Siindermann
7
Summary and Conclusion
The SPM regime in the southern North Sea is dominated by successions of storm
events and calm periods. For the adequate simulation of this SPM regime, a numerical SPM transport model needs input information about both the current
field and the surface waves. The SPM's temporal variability in the North Sea is
demonstrated by the comparison of two extreme weather situations.
The computed results of the model are compared with the measured SPM data
of the British North Sea Project (NSP). The distribution of mean SPM concentrations in the southern North Sea is not satisfactorily simulated, but the temporal
variation of SPM concentrations is modelled quite well. It is concluded that erosion and deposition of SPM are well simulated by the SPM transport model.
The model results are used to assess the representativity of the NSP data with
regard to its temporal variation. It is concluded that the time frequency of NSP
survey cruises was, in fact, sufficient to give a representative picture of the complete NSP period August 1988-0ctober 1989. The spatial representativity of the
measured NSP data, however, was shown to be imperfect.
Finally a recommendation is given: the planning of future projects with repeated survey cruises around a network of stations may include representativity
tests with a numerical model. Such tests will decrease the risk of getting incomplete results.
Acknowledgements
This study was funded by the participating institutions and the Bundesminister
fur Bildung, Wissenschaft, Forschung und Technologie under grant 03FOlllC.
The authors wish to thank the Bundesamt fur Wehrtechnik und Beschaffung
(Koblenz) and the Amt fUr Wehrgeophysik (Traben-Trarbach) for making available the wave data of the North Sea.
References
AI-RabehAH,Gunay N (1992) On the application of a particle dispersion model. Coastal Eng.,
vol. 17, 195-210
Boudreau BP (1986) Mathematics of tracer mixing in sediments: LSpatially-dependent, diffusive mixing. Amer. J. Sci., vol. 286, 161-198
Dyer KR, Moffat TJ (1998) Fluxes of suspended matter in the East Anglian plume, southern
North Sea. Continental Shelf Research (accepted)
Eisma D, Kalf J (1979) Distribution and particle size of suspended matter in the Southern
Bight of the North Sea and the eastern Channel. Netherlands Journal of Sea Research 13
(2),298-324
Eisma D, Kalf J (1987) Distribution, organic content and particle size of suspended matter in
the North Sea. Netherlands Journal of Sea Research 21 (4),265-285
Eisma D, Irion G (1988) Suspended matter and sediment transport. In: Salomons W, Bayne
BL, Duursma EK, Forstner U (eds) Pollution of the North Sea - An Assessment. SpringerVerlag Berlin Heidelberg New York, 20-35