A Hybrid Parallel Algorithm to Solve Tridiagonal System of Ocean Model

Aiming at the characteristics of Alternative Direction Implicit (ADI) scheme that is used in the discretization of the governing equations of most ocean models, a hybrid parallel tridiagonal linear system algorithm, based on the Parallel Diagonal Dominant (PDD) and the Parallel Cyclic Reduction (PCR) algorithm, is developed in this paper. The main concept of the hybrid parallel algorithm is that the processes in the parallel system are divided into groups and the PDD algorithm is used to implement parallelization between groups. In each group, the PCR is used to implement the parallelization instead of PDD. By doing so, parallel efficient and computational accuracy could be obtained in the same time. To examine the algorithm of the hybrid parallel efficiency, a Global Reduced Gravity Ocean model (GRGO) is paralyzed, and the results show that this hybrid parallel algorithm can give us a better accuracy and higher efficiency compared to that using the traditional domain decomposition method.