Improvement of the ocean pollutant transport model by using the surface spline interpolation

Abstract

The independent point scheme (IPS) is applied to inverting initial condition with the adjoint method for the ocean pollutant transport model in this work. As an improvement, the linear Cressman interpolation is removed and the surface spline interpolation is implemented in the IPS. A series of numerical experiments are carried out to test and compare the improved IPS. And experiment results show that through applying the improved IPS, what is further reduced is mean absolute errors between simulation results and observations. Moreover, the inverted distributions are more smooth, accurate and reasonable. In addition, the application of improved IPS also reduces the variables that need to be inverted and promotes the computational efficiency. By these numerical experiment results, it is demonstrated that the combination of improved IPS and adjoint method can be used for the inversion of initial conditions and parameters estimation more effectively and reliably.

Application of Dynamically Constrained Interpolation Methodology to the Surface Nitrogen Concentration in the Bohai Sea

“…Considering the convection and diffusion processes, the governing equation of marine pollutant transport model is presented as follows [17,26,27] ∂C∂t+u∂C∂x+v∂C∂y+w∂C∂z=∂∂xfalse(AH∂C∂xfalse)+∂∂yfalse(AH∂C∂yfalse)+∂∂zfalse(KH∂C∂zfalse)−rC where C denotes the concentration of pollutants; t and x , y , z are the symbols of time and space, respectively; u and v represent the horizontal velocities (in x and y directions, respectively) and w represents the vertical velocity (in z direction); A H and K H denote the horizontal and vertical diffusion coefficients ( A H = 100 m 2 /s, K H = 0.00001 m 2 /s), respectively; r is the pollutant attenuation coefficient, and r = 0, which means that the pollutant is treated as conservative substance [17]. For the finite difference scheme readers can be referred to the Appendix A.…”

“…The computational domain is the Bohai Sea (37° N–41° N, 117.5° E–122.5° E) with a 4′ × 4′ grid resolution. The computing time is 30 days and the time step is set to be 6 h. The three-dimensional Regional Ocean Model System (ROMS) provides the hydrodynamic flow field used in numerical experiments of present study [27].…”

Modelling of Water Pollution Propagation in the Sevastopol Bay

“…Исследования гидролого-гидрохимических и гидродинамических характеристик Севастопольской бухты проводились ранее как на основе данных натурных наблюдений [1,2], так и по результатам математического моделирования [3,4]. Увеличившийся объем информации об окружающей среде и современные междисциплинарные математические модели позволяют с большей точностью прогнозировать состояние и динамику морских прибрежных вод [5][6][7][8][9], в том числе и для Черного моря *.…”

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“…Исследования гидролого-гидрохимических и гидродинамических характеристик Севастопольской бухты проводились ранее как на основе данных МОРCКОЙ ГИДРОФИЗИЧЕСКИЙ ЖУРНАЛ том 35 № 1 2019 6 натурных наблюдений [1, 2], так и по результатам математического моделирования [3,4]. Увеличившийся объем информации об окружающей среде и современные междисциплинарные математические модели позволяют с большей точностью прогнозировать состояние и динамику морских прибрежных вод [5][6][7][8][9], в том числе и для Черного моря *.…”