摘要
通过统计和动力学分析结果的验证,可以得到:(1)欧洲中期数值预报产品是预报副高中期活动的重要依据,并且预报值的平移订正不可能对预报准确率有多大的改进。(2)不考虑天文潮汐可能是1998年欧洲中期数值预报产生较大误差的重要原因。(3)进一步分析找到二条判断欧洲中期数值预报因不考虑天文潮汐将发生较大误差的指标: ① 当交点月奇异点月下点 54.7 线与当日20时500 hPa的 50～150 E 范围内副热带急流槽线相重合,并与等温线夹角 α>60 °时,那末若以奇异点后0～2天作为初日,欧洲中期数值预报120 E 588线北界预报将出现连续三天大于等于2个纬距的连续性错误(7/9),反之,将不出现连续性错误(13/13);② 在不满足上述情况下,如果54.7 跋咄ü至迅备咧涞脱骨保?则在交点月奇异点当日出现离散性错误(5/7),反之,将不出现错误(6/6)。(4)1999～2000年汛期实际应用结果基本上证实了上述二个指标。
By analyzing statistics and dynamics in this text, we can come to such conclusions: (1) The ECMWF medium-term numerical forecast can forecast medium-term activity of subtropical high, and the accuracy rate of forecast cannot have large improvement by transnational corrections. (2) The important cause that ECMWF medium-term numerical forecast made errors in 1998 is that astronomical tide is not included in the model. (3) Two indexes are found from which it can be judged that ECMWF medium-term numerical forecast will make errors for disregarding the astronomical tide in the model : ① when the 54.7 ?line under the moon of nodal month astronomical singularities coincides with the trough-line of subtropical jet flow from 50 癊 to 150 癊 on 500 hPa at 2000 L. T.The same day, and is approximately vertical (α>60 °) with the isotherm, then the day in 0～2 days after nodal month astronomical singularities is defined as initial day, then in three days after the initial day, ECMWF medium-term numerical forecast of north latitude of 588 line on 120 癊 will make continuance errors by two latitudes (7/9). Otherwise, it won't make continuance error (13/13), ② otherwise, if the 54.7 ?line is in the range of low pressure between two high pressures, then there is dispersed error on the day of nodal month astronomical singularities (5/7). On the contrary, there is not any error (6/6).
出处
《热带气象学报》
CSCD
北大核心
2002年第4期351-358,共8页
Journal of Tropical Meteorology
关键词
1998年
副热带高压
数值预报
误差分析
天文潮汐
动力学分析
ECMWF medium-term numerical forecast
subtropical high
error analyze
astronomical tide
analyze of dynamics
