探空资料同化应用研究:（Ⅰ）两种质量控制方法对比

本文以探空温度资料和T639模式资料为基础,对比双权重质量控制方法与传统标准差法质量控制的差异,结果表明:传统法得出的平均值、标准差均偏大。离群点的判断对标准差敏感度高,受平均值的影响小。两种质量控制方法得出的平均值相差较小,标准差相差较大,质量控制后,传统法对平均值和标准差的改变较大,而双权重法使平均值、标准差略有变化,因此双权重标准差法的稳定性好。质量控制结果显示:双权重法能全部剔除由传统法确定的离群点,还能检查出传统法不识别的离群点。两种方法在探空高层离群点判断上存在较大有差异,虽然双权重标准差法使得离群点增加很多,但提高了观测增量的精确度,有效保障了探空资料质量。双权重质量控制结果使探空观测与T639模式的温度增量的相关系数与标准差均有改进,尤其在西藏东部改进较大。 

Analysis of the Radiosonde Temperature Assimilation:(I) Comparison Two Methods of Quality Control

Analysis the difference between the Bi-weight mean Quality Control (BQC) method and the Traditional mean Quality Control (TQC), by using the radiosonde and T639 temperature data. The results show that The mean value and standard deviation of TQC are larger than BQC, but the difference of mean value is small difference and Standard deviation is opposite. Determine of the outliers is highly sensitive with standard deviation but little influenced by the mean. after the QC, the changes of the mean and standard deviation of TQC are larger than the BQC, Reveals that the BQC is stabilizing. Meanwhile, the BQC could distinguish all outliers by TQC, but also check out other outliers. the numbers of outliers are different in the upper level of sounding, though outliers increased more by the TQC, it ensures the temperature data quality. the correlation coefficient and standard deviation are improved greater, especially in eastern Tibet.