摘要
在文献 [1]的基础上 ,设计了将逐候纬向平均高度距平场非线性动力学区域预报和T42L9谱模式动力延伸预报结合的方案 ,即将非线性预报结果转化为模式的静力扣除谱系数 ,然后在模式积分过程中的每一步取代其相应部分 ,实施过程订正。多个例试验结果表明 ,这种途径在减少了模式纬向环流的预报误差的同时 ,还通过非线性波流相互作用 ,改善了部分波动分量的预报。
Based on Chen et al, the scheme of the combination of the pentad mean zonal hei g ht departure nonlinear prediction with the T42L9 model prediction was designed, in which the pentad zonal heights at all the 12 initial value input isobar lev els from 50 hPa to 1000 hPa except 200, 300 500 and 700 hPa were derived from no nlinear forecasts of the four levels by means of a good corelation between neigh boring levels. Then the above pentad zonal heights on 12 isobar levels were tra nsf ormed to the spectrum coefficients of the temperature at each integration step o f T42L9 model In final, the nudging was made. On account of a variety of error a ccumulation, the pentad zonal components of the monthly height on isobar levels output by T42L9 model were replaced by the corresponding nonlinear results once more when integration was over.Multiple case experiments showed that such combination of two kinds of predictio n made an improvement in the wave component results of model as a result of wave flow nonlinear interaction while reducing the systematical forecast errors. Na mely the monthly mean height anormaly correlation coefficients over the high and mid latitude of the Northern Hemisphere, over the Southern Hemisphere and o ver the Globe is increased respectively from 0.249 to 0.347, from 0.286 to 0.387, an d from 0.343 to 0.414 ( relative changes of 31.5%, 41.0 and 18.3%). The monthly mean root mean square of T42L9 model over the three areas was considerably d ecreased, the relative change over the Globe reaching 44.2%. The monthly mean a normaly correlation coefficients of wave 4-9 over the areas were up to 0.392, 0 .200 and 0.295, with the relative change of 53.8%,94.1% and 61.2%, and corr espon dingly their root mean square were decreased respectively with the rate of 8.5 %?6.3% and 8.1%. At the same time the monthly mean pattern of parts of cas es were presented better.
出处
《气象学报》
CAS
CSCD
北大核心
2004年第1期11-19,共9页
Acta Meteorologica Sinica
基金
国家自然科学基金项目(40 1 750 1 3)
中国科学院项目(ZKCX 2 SW 2 1 0 )
国家"九五"科技攻关 96 90 8项目 0 2 0 1
