Marine pollution in the sensible North and Baltic Sea forces an international aerial surveillance. Within this framework the German aerial surveillance operates an advanced instrumentation on board of two 'Dornier 228' aircrafts. The instrumentation consists of a set of state-of-the-art imaging remote sensors, like side looking airborne radar (SLAR), IR/UV line scanner and particularly a microwave radiometer (MWR) and a laser-fluoro-sensor (LFS). The most important aim is to detect oil discharges on the water surface, emitted accidentally or illegally. In case of discharge, the pollution has to be classified and quantified with a high accuracy. Another aim is to monitor biological and hydrological parameters, as there are the concentration of chlorophyll and dissolved organic matter (DOM) or the growth of phytoplancton.This paper describes the set of instruments and their potential to fulfill these demands. The SLAR operates to locate oil discharges and phytoplancton, whereas the IR/UV scanner allows to distinct the detected area. The IR/UV and especially the MWR sensor allow to quantify the thickness of the oil film. Finally, the LFS classifies the oil species as well as organic material. Emphasis is placed on the results of the sensor measurements and their synergy effects. The combination of the sensor data yields value added information for the operational users.An use of satellite data to improve the operational surveillance will be discussed. The potential and limitations of satellite and airborne data for the surveillance tasks will be compared.
In shallow waters the wave height distribution significantly differs from Rayleigh distribution during extreme wind conditions. The EurOtop manual (Pullen et al. 2007) recommends the use of a composite Rayleigh-Weibull distribution proposed by Battjes and Groenendijk (2000) in order to describe the wave statistics in shallow waters. A test of this recommendation by using wave measurements with continuously operated radar level gauges at three different sites at the German North Sea coast for comparison revealed the necessity for a change in the parameterization given in the EurOtop manual. References Barjenbruch, U., S. Mai, N. Ohle, and U. Mertinatis. 2002. Monitoring Water Level, Waves and Ice with Radar Gauges, Proceedings of the Hydro 2002 Conference, DHyG, 328-337. Barjenbruch, U., and J. Wilhelmi. 2008. Application of radar gauges to measure the water level and the sea state, Proceedings of 31st International Conference on Coastal Engineering, ASCE, 687-695. Battjes, J.A., and H.W. Groenendijk. 2000. Wave height distributions on shallow foreshores, Coastal Engineering, 40, 161-182. http://dx.doi.org/10.1016/S0378-3839(00)00007-7 Burcharth, H.F., P. Frigaard, J. Uzcanga, J.M. Berenguer, B.G. Madrigal, and J. Villanueva. 1996. Design of the Ciervana breakwater, Bilbao, Advances in coastal structures and breakwaters, Thomas Telford, London, 26-43. Forristall, G. 2008. Offshore LNG terminal designs must overcome complications of shallow water, Oil & Gas Journal, 106(43). IAHR Working Group on Wave Generation and Analysis. 1989. List of Sea-State Parameters, Journal of Waterway, Port, Coastal and Ocean Engineering, 115(6), pp. 793-80 http://dx.doi.org/10.1061/(ASCE)0733-950X(1989)115:6(793) Klopman, G., and M.J.F. Stive. 1989. Extreme waves and wave loading in shallow water, Proceedings of E&P Forum Workshop: Wave and current kinematics and loading, Paris, Oct. 25-26. Longuet-Higgins, M. S. 1952. On the Statistical Distribution of the Heights of Sea Waves. Journal of Marine Research, 11(3), 245–266. Mai, S. 2008. Statistics of Waves in the Estuaries of the Rivers Ems and Weser - Measurement vs. Numerical Wave Model, Proceedings of the 7th Int. Conf. on Coastal and Port Engineering in Developing Countries COPEDEC, CD-ROM. Nelson, R.C. 1994. Depth limited design wave heights in very flat regions, Coastal Engineering, 23, 43-59. http://dx.doi.org/10.1016/0378-3839(94)90014-0 Pullen, T., N.W.H. Allsop, T. Bruce, A. Kortenhaus, H. Schüttrumpf, and J.W. van der Meer. 2007. EurOtop – Wave Overtopping of Sea Defences and Related Structures: Assessment Manual, Die Küste, 73, 193 pp. (online:
Physical processes in coastal waters and estuaries extend their influences on many economic and ecological processes in the coastal regions and affect the safety of the coastal defences. In a context with the global climate change, these physical processes underlie also inherent modifications. In order to win an impression of such future changes and of the probability of their occurrence, physically consistent simulations of these processes are used to describe how wind-waves and currents interact. This paper presents an offline-coupled simulation using the models HAMSOM (HAMburg Shelf Ocean Model) and SWAN (Simulating Waves Nearshore). These stateof-the-art models excel by high computing speed, so that they offer an opportunity to simulate hydrological conditions and physical processes over longer time periods, e.g. decades. For the influence of currents on the waves, we estimate less influence on tidal flats, but stronger influence in the tidal channels. Improvements in parameter estimation that were achieved by the interaction of currents and waves are described and discussed; we estimate new drag-coefficients for the hydrodynamic simulation. Because long-term simulations need to be simplified, a method is examined and presented that bypasses the direct online-coupling of models. For the aim of long term simulation improvements of the surface drag coefficient are useful, because online-coupled wind-wave models overcome the available machine time for climate runs. Our method yields an optimization regarding computing economy and physical consistency of simulations.
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