基于FNL和GRAPES分析场的探空温度数据的误差分析

Error Analysis of Sounding Temperature Data Based on the FNL and GRAPES Analysis Fields

分别以美国NCEP的FNL分析场和我国GRAPES的分析场为参考对北京探空站的温度数据从观测余差、平均偏差、标准偏差、概率密度分布、峰度系数、偏度系数、相关系数和均方根误差多个角度进行评估。根据评估结果对探空温度数据进行质量控制,并分析质量控制效果。结果显示:探空温度数据质量较高,误差基本在±1℃以内。基于FNL分析场的评估结果与GRAPES的评估结果有略微差异。单个时刻选取的可疑值和错误值的阈值具有根据基于分析场余差的分布特征自适应确定的特点。根据评估进行质量控制后的探空温度质量得到改善,且数据保留了原有的特征。该质量控制方法能够有效地消除季节性差异,且质量控制后两个参考标准的评估结果基本一致。

Based on the FNL data of the United States NCEP and the analysis fields of Chinese GRAPES,the temperature data of Beijing sounder station are evaluated,including observation residuals,average deviations,standard deviations,probability density distributions,kurtosis coefficients,skewness coefficients,correlation coefficient and root mean square error.Then,the quality control of temperature data of sounding is conducted and the quality control effect is analyzed according to the evaluation results.The test results show that the sounding temperature is of good quality and the error is within±1℃basically.There is a slight difference between the evaluations of the FNL analysis and the GRAPES results.The threshold values of the suspicious value and error value selected at a single time can determined by itself adaptively according to the characteristics of residual distribution based on the analysis fields.The quality of the sounding temperature is improved and the data retain the original characteristics after quality control according to the evaluation.The quality control method can effectively eliminate the seasonal difference and the evaluation results of the two reference standards are basically consistent after quality control.