Passive Tracer Transport in Ocean Modeling: Implementation on GPUs, Efficiency and Optimizations

Numerical simulation of the ocean general circulation remains one of the most computationally demanding problems. For both climate and forecast research, the speedup of the calculations is still an ongoing challenge. This problem can be remedied by developing new computationally efficient algorithms. Another, and in fact complementary, approach is to utilize massively parallel coprocessors such as Graphics Processing Units (GPUs). In this study, we consider the GPU implementation efficiency of the advection schemes commonly used in tracer transport algorithms for ocean modeling and compare it with the implementation on a Central Processing Unit (CPU). The simulations on refined grids were found to be highly efficient when implemented on the GPU, in contrast to the coarse resolution. We also consider a number of optimization techniques to improve GPU efficiency in the latter case.