By Coherens Mode Is In The Bohai Sea Marine Environment Simulation Applications

A 3-D costal phytoplankton ecosystem dynamics model based on COHERENS is established, and is applied to simulate the physical environment and phytoplankton ecosystem of the Bohai Sea during 1982 to 1993. NCEP Reanalysis data is interpolated to be the meteorological forcing field, while climatologic data is used as the initial field. Furthermore, actual physical boundary conditions are used to build a real physical environment of the Bohai Sea. Based on the historical data and the existing research, a series of the biological and chemical parameters, initial conditions and forcings, which can be regarded as the typical characteristics of the Bohai Sea, are chosen to represent the general aspects of the biological part of the phytoplankton ecosystem.The spatial distribution and seasonal changing characters of sea temperature, salinity, current, nitrate, chlorophy-a and dissolved oxygen have been reproduced by this simulation. Moreover, the inter-annual variation trends of sea temperature, salinity, nitrate and chlorophy-a have been simulated and analysed. The result shows that temperature, salinity and the content of nitrate of Bohai Sea has increased during 1982-1993, nevertheless the increasing speed of salinity and nitrate is lower than the analysis of observing data. It is belived that the significant decrease of river discharge is the main reason for salinity increase. However, the river runoff remains unchanged in this simulation during 1982-1993. Furthermore, the resources of nitrate in this model consist of river discharge and minaralizatin, the atmosphere diposition and chemical pollution are not involved. That might be the reason why salinity and nitrate increase slowly in this simulation.The contents of the thesis include the latest development of marine ecosystem dynamics model, the inter-annual fluctuation character of marine environment of Bohai Sea, brief introduction of COHERENS model, numerical experiments for model testing, numerical simulation of the physical and biological environment of Bohai Sea and the analysis of result.