山西岢岚地区NCEP资料与地面观测资料的年变化对比

摘要

利用2000—2014年山西岢岚地区地面观测资料和NCEP （1°×1°）再分析资料，采用线性趋势和相关系数等方法，探讨NCEP再分析资料中2 m地面温度、2 m相对湿度、地面气压及10 m风速在岢岚地区的可信度问题。结果表明：（1）2005年以前，NCEP再分析资料2 m温度偏低，之后开始偏高，且与地面观测资料的偏差有逐年增大趋势，每10 a约增加1．4℃；两者相关性高，多年相关系数平均值达到0．9557；（2）相对湿度均呈减小趋势，2006年以前，NCEP 2 m相对湿度偏大，此后开始偏小，相对湿度的多年平均绝对差为14．5522％，且后9 a（2006—2014）均小于多年平均绝对差；两者相关系数值呈增大趋势，年平均值为0．7167；（3）NCEP地面气压总体偏大，平均绝对差值呈明显减小趋势，最小值0．5889 hPa出现于2014年，多年平均值为4．2725 hPa；两者相关系数呈增大趋势，多年平均值达到0．9625；（4）历年NCEP 10 m地面风速均偏大，但与地面观测资料的偏差呈减小趋势，每10 a约减小0．4 m·s－1，多年平均绝对差值为1．7996 m·s－1，而2005—2014年的平均绝对差值皆小于多年平均值；两者相关系数较小，但逐年呈微弱上升趋势，其多年平均值只有0．4849。%Based on the NCEP (1°×1°)reanalysis data and ground observations during 2000-2014 in Kelan of Shanxi Province,the reliability of NCEP reanalysis data of temperature and relative humidity at 2-meter height,wind speed at 10 m height and ground pres-sure was discussed by using statistical analysis methods including linear trend,mathematical statistics and correlation coefficient etc. Results are as follows:(1 )NCEP temperature at 2 m height was lower before 2005 ,and later it became higher.The deviation of ground observations and NCEP temperature at 2 m height showed an increasing tendency year by year,and it increased about 1 .4 ℃every 10-year.The NCEP temperature at 2 m height presented high correlation with ground observations,and the average of multi-year correlation coefficient reached 0.9557.(2)The relative humidity of both showed a decreasing trend.NCEP relative humidity at 2 m height was higher before 2006,and later it became lower.The average of multi-year mean absolute deviation was 14.5522%. From 2006 to 2014,the absolute deviation was all less than the multi -year mean absolute deviation.Their correlation coefficient showed an increasing trend,and the multi -year average was 0.7167.(3)Compared with ground observations,the NCEP ground pressure was higher in most years.And their mean absolute deviation presented a clear decreasing trend,the minimum value of abso-lute deviation was 0.5889 hPa in 2014,and its multi-year average was 4.2725 hPa.Their correlation coefficient showed an increasing trend,and the multi-year average reached 0.9625.(4)The NCEP wind speed at 10 m height was larger in all years,and their devi-ation showed a decreasing trend,which decreased about 0.4 m·s-1 every 10 years.The average of multi-year absolute deviation was 1.7996 m·s-1,and from 2005 to 2014,the mean absolute deviations were all less than the multi-year average.Their correlation co-efficient was relatively small,but there was a weak rising tendency year by year,and its multi-year average was only 0.4849.