非线性正规模初值化及其对资料同化和预报的影响

文章介绍了国家气象中心中期数值预报谱模式（T42L9）的非线性正规模初值化方案（NNMI）。讨论了该方案对资料同化和预报的影响。试验表明，应用前5个垂直模，经2次迭代能够得到一个对分析资料修正较小的平衡初始场。它成功地消除了预报中虚假的高频重力波振荡，对改进资料同化和模式预报起了重要作用。

Non-linear Normal Mode Initialization and Its Effect on Data Assimilation and Forecasting

The non-linear normal mode initialization(NNMI)for a spectral model of medium-range NWP in NMC,SMA is described, and its effect on data assimilation and forecast-ing is discussed.It is experimentally shown that in terms of two iterations by using firstfive vertical modes,a balanced initial field appropriate to data analysis is obtained.It aL-so shows that NNMI is highly successful in eliminating the spurious high frequency gravity wave oscillation in forecasting,therefore,it plays an important role in improv- ing data assimilation and model forecasting.