Numerical Simulation Of Summer Circulation And Oil Spill Drift In Bohai Sea

In recent years, with the increasing in production, exploration, refining, andtransportation of crude oil and petroleum products in each country, the oil spillemergencies increase with years, which caused more and more losses, and the tensof thousands of oil flow into the ocean, rivers and other waters, not only resulting inserious damage to the environment, but also causing great harm to the humanthrough the food chain.After the oil spill incident occurred, the spilled oil will drift and diffuse under thecombined effect of tidal currents, wind currents and wind. Thus, it is necessary toresearch and simulate tidal currents, wind currents of contaminated seas, and establishoil spill model for the oil spill drift speed and direction forecasts, which will providescientific basis for taking effective measures in respond to oil spill.This paper firstly gives a brief introduction for the background and meaning ofthis study, and then makes a detailed description for domestic and internationalresearch present condition of oil spill model about surface wind, the tidal currents,steady circulation in the Bohai Sea. The specific procedures and conclusions are listedas follows:1.On the basis of using of MM5model to establish the wind forecast model ofthe Bohai Sea, this study makes numerical prediction for wind in June2011of theBohai Sea, then simulates the hourly wind field and calculated the daily and monthlyaverage wind. After verifying meteorological data in several cities along the coast ofthe above mentioned month, the results show good to prove the accuracy of the windprediction, it will provide wind data for calculation of the currents and building the oilspill model.2. After using the three-dimensional numerical model of FVCOM, tidal currentsforecast model of the Bohai Sea is established, which is used to simulate the foursub-tidal trend （M₂and S₂, K₁, O₁）, and select four validation points for comparison the simulated tide, current direction and velocity with measured value. Meanwhile,the tidal characteristics, current characteristics and vertical velocity distributioncharacteristics were analyzed and compared with previous results, and abovecomparison results prove accuracy of the trend forecast models. On this basis, thetidal current in the Bohai Sea in June2011is forecast, providing the necessary tidalcurrent for following discussion.3. The wind data in Bohai Sea in the June2011is obtained by forecasting withwind forecasting model. The wind-currents in the Bohai Sea in June2011aresimulated by FVCOM three-dimensional numerical model simulation. According tothe analysis of surface and bottom wind-driven circulation, and compare withprevious results, the accuracy of the wind currents calculation is well proved.4.On the basis of successful simulation of wind field, tidal current andwind-currents, the oil spill drift trace forecast model is established by using themethod ofLagrange particle tracking. The oil spill drift trace in the Bohai Sea issimulated in following two cases:（1） together interaction between tidal current sandhourly wind, and （2） together influence of tidal currents, wind-currents and hourlywind. Simultaneously, depending on the satellite images of Penglai19-3Oil Fieldspill in June2011, selected five validation points and10time were verified, and thelocation simulated by oil spill model is consistent with the location of the actualmonitoring, which illustrates the validity of the model. After considering thecombined effect of tidal currents, wind currents and hourly wind, the simulated resultsare much closer to the actual situation, which can provide more accurate scientificbasis in timely forecasting and making contingency plans for the sudden spill.