MASNUM海浪模式对波数离散角度的敏感性数值实验

Numerical experiments on wavenumber directional discretization in the MASNUM Wave Model

本研究基于MASNUM 第三代海浪数值模式, 利用2005 年太平洋区域17 个浮标的有效波高数据做检验, 对海浪模式波向在12、24、36 和48 四种离散划分进行了数值实验.结果表明, 在太平洋区域中纬度和太平洋东部地区, 36 个角度划分是较好的选择, 而在太平洋低纬度, 24 个波向划分是较好的选择; 冬、夏季数值模拟与检验对比表明, 较好的角度划分数分别是24 和36; 有效波高在2.0-4.0m 时, 较好的波向划分数是24; 有效波高小于2.0m 时, 24 与36 个波向划分数值模拟结果非常相近.而在高海况下, 36 个角度划分是较好的选择.上述结果均比采取波向离散12 的结果有明显改进.文章认为, 应使用高于12 的波数离散数划分, 24 或36 个波数角度离散划分是较好选择.

This study shows some numerical experiments based on the 3^(rd) generation wave model of MASNUM,in four cases of different wavenumber directional discretization numbers: 12,24,36,and 48,respectively in the Pacific Ocean in 2005,and compares the model results with 17 buoy observations. These results indicate that the discretization number of 36 is the best choice for the model setting in the mid-latitude area and the eastern Pacific,while the discretization number of 24 is the best choice in the low latitude region. Comparison shows that the best discretization number is 24 in winter while 36 in summer. We also find that when significant wave height is between 2.0 and 4.0 m,the best discretization number is 24. When significant wave height is lower than 2.0 m,24 and 36 are both proper choices. We recommend choosing 36 when under poor ocean conditions. All above results show obvious improvements comparing with the case of discretization number 12. Therefore,we believe that the discretization number of the MASNUM wave model should be greater than 12,and that the number of 24 or 36 is a better choice.