Abstract:

Based on the T213 L31 numerical prediction products，the height field，temperature field，wind field，vertical velocity field， and humidity field on every pressure level in range of east Asia have been evaluated by using 24 hours variable correlation coefficient． The results are as follows: 1) For the height field forecast，the predicting length that could pass the significance test at the level of α = 0． 001 was 10 days，and the higher credible ( 24 h variable correlation coefficient more than 0． 4) predicting length could reach 6 － 7 days at the middle and upper layer of troposphere and 5 days at the middle and lower layer of troposphere; 2) For the temperature field forecast，the predicting length that could pass the significance test at the level of α = 0． 001 was 9 days，and the higher credible predicting length could reach 4 days at the middle and upper layer of troposphere，and 5 days at the middle and lower layer of troposphere; 3) For the wind field forecast，the predicting length that could pass the significance test at the level of α = 0． 001 was 8 days，and the higher credible predicting length could reach 5 days at the upper layer of troposphere，and 4 days at the middle layer of troposphere， and 3 days at the lower layer of troposphere; 4) For the vertical velocity field forecast，the predicting length that could pass the significance test at the level of α = 0． 001 was 5 days，and the higher credible predicting length could only reach 1 － 2 days at troposphere; 5) For the specific humidity field forecast，the predicting length that could pass the significance test at the level of α = 0． 001 was 6 days，and the higher credible predicting length could reach 2 days at the middle layer of troposphere，and 3 － 4 days at the lower layer of troposphere．

Key words: T213 L31 numerical prediction products, 24 h variable correlation coefficient, verification

摘要：

气象要素的变量可反应天气系统的变化趋势，所以，在数值预报产品释用业务中，气象要素场及一些物理量的24 h 变量经常作为重要的预报因子，因此，有必要以24 h 变量相关系数为指标，对数值预报产品进行检验。利用国家气象中心T213 L31 数值预报产品，对东亚范围内2006 ～ 2011 年对流层各等压面的高度场、温度场、风场、垂直速度场和水汽场的预报，以24 h 变量相关系数为指标，进行了检验。结果表明: 1) 高度场预报，通过相关显著性水平α = 0．001 检验的时效为10 d，高可信度( 24 h 变量相关系数＞ 0．4) 的时效，对流层中上部6 ～ 7 d，对流层中下部5 d; 2) 温度场预报，通过α =0．001 水平相关显著性检验的时效为9 d，高可信度的时效，对流层中上部4 d，对流层中下部5 d; 3)风场预报，通过α = 0．001 水平相关显著性检验的时效为8 d，高可信度的时效，对流层上部、中部和下部分别为5 d、4 d 和3 d; 4) 垂直速度场预报，通过α = 0．001 水平相关显著性检验的时效为5 d，高可信度的时效仅为1 ～ 2 d; 5) 水汽场预报，通过α = 0．001 水平相关显著性检验的时效为6 d，高可信度的时效，对流层中部2 d，下部3 ～ 4 d。这些将为T213 L31 数值预报产品的合理有效利用提供参考依据。

关键词: T213 L31 数值预报产品, 24 h 变量相关系数, 检验