从初始化中排除潮汐信号方案在全球模式中的应用

THE APPLICATION OF TIDAL SIGNAL EXCLUSION SCHEME FROM INITIALIZATION IN A GENERAL CIRCULATION MODEL

对国家气象中心全球预报模式T106L19原有的标准非绝热正规模初始化方案要求外强迫是准静止这一假定进行了修正,将潮汐信号在初始化条件中适当地表达出来并将其从中排除。与三维变分分析SSI的联接对比试验表明,修正潮汐信号后的新方案在消除高频重力波振荡方面与标准初始化方案有同样的效果,但该方案较标准初始化更好地捕捉住了地面气压的半日变化,更接近于未经初始化的分析场。模式7天预报500 hPa高度场与分析场的对比检验表明,新方案的距平相关系数和均方根误差都较原方案有明显的改进。

In this paper, some corrections had been made to the assumption that the forcing is quasi-static, which is the basis of the nonlinear diabatic initialization scheme adopted by a global model T106L19. Thus the tidal signal is expressed and excluded from the initialization scheme. It shows that the new scheme captures the semi-diurnal pressure variation and is closer to the field that is not initialized. Compared with the standard initialization scheme, the anomaly correlation coefficients and RMS of 500 hPa geopotential height simulated under the new scheme have improved significantly.