Storm surges in the Western Black Sea. Operational forecasting

The frequency of the storm surges in the Black Sea is lower than that in other regions of the World Ocean but they cause significant damages as the magnitude of the sea level set-up is up to 7-8 times greater than that of other sea level variations. New methods and systems for storm surge forecasting and studying their statistical characteristics are absolutely necessary for the purposes of the coastal zone management. The operational forecasting storm surge model of Meteo-France was adopted for the Black Sea in accordance with the bilateral agreement between Meteo-France and NINMH. The model was verified using tide-gauge observations for the strongest storms observed along the Bulgarian coast over the last 10 years

Assessment of radionuclide contamination in the Black Sea using POSEIDON/RODOS system

The coupled system of the 3D hydrodynamical model THREETOX and the radiological box model POSEIDON-R, developed in the framework of the European system RODOS for emergency response to a nuclear accident, was applied to the Black Sea for reconstruction and outlook of the radionuclide contamination in result of bomb testing and the Chernobyl accident. For the model verification hydrophysical data was obtained from historical records of up to 15180 observational stations in the Black Sea. The data was grouped by months in 1°by1° spatial squares and homogenised in the vertical with application of the method of Reininger and Ross. The radiological data was derived from literature sources mainly based on the expeditions of "Typhoon", IBSS, MHI, Hydrometeorological service (all from the former USSR), "K. Piri" and "Knorr" (US-Turkish) expeditions in the Black Sea. The vertical radionuclide stratification was obtained as one profile "mean for the whole sea" due to the scarce data. The spatial reconstruction of the hydrophyscal and radiological fields were done by gridding of the arbitrarily spaced data applying the method of "splines in tension" and eliminating aliasing by the median method. The THREETOX model was used for re-analysis of radionuclide transport. The 137Cs concentrations calculated with POSEIDON-R in water and biota are compared with the collected data. A good agreement was found due to the implemented dynamic food chain model