摘要
针对双权重标准差法对探空温度质量控制中阈值参数不确定的问题,提出了以正态波形指标偏度和峰度为判定依据的阈值Z参数优化算法。利用2017年福建3部探空温度资料和ERA5模式再分析温度数据,对探空温度增量数据进行不同数据集质控前后对比分析总结出:峰偏值CKS随阈值Z的分布曲线表明阈值Z偏大则会造成质控不完全,阈值Z偏小则会造成过度质控;以峰偏值CKS所确定的最优阈值Z双权重标准差法比固定阈值的更符合模式同化系统正态分布要求,为探空温度数据在模式同化的应用提供了更好的质控方法。在质控前后温度增量分布特征上,温度观测增量总是以某一固定增量值在整个气压高度上剔除离群值,其中57.15%的离群点主要分布在0~100 hPa范围内,42.85%的离群点均匀分布在100~1000 hPa范围内,其中0~100 hPa范围内温度增量绝对值大于10℃的异常点是由于温度传感器受太阳辐射等因素影响超出了正常探测误差范围,这些异常点可以在质控前提前剔除,进一步提升探空温度数据质量。
Aiming at the problem of uncertainty regarding the threshold parameters in the quality control of radiosonde temperature using the bi-weight standard deviation method,an optimization algorithm for threshold Z parameters based on the skewness and normal waveform indicators is being proposed.By utilizing the temperature data from three radiosonde stations in Fujian in 2017 and the ERA5 model reanalysis temperature data,a comparative analysis of the different datasets of the sounding temperature increment data before and after quality control is conducted.The distribution curve of the kurtosis-skewness value CKS with threshold Z indicates that a higher threshold Z will result in incomplete quality control,while a lower threshold Z will result in excessive quality control.The optimal threshold Z of the bi-weight standard deviation method,as determined by the kurtosis-skewness value CKS,is more consistent with the normal distribution requirements of the model assimilation system than the fixed threshold of the bi-weight standard deviation method.This provides a better method for quality control of radiosonde temperature data in model assimilation.Regarding the distribution characteristics of temperature increment before and after quality control,the temperature observation increment consistently removes outliers from the entire pressure atmosphere using a fixed increment value.Around 57.15%of outliers are primarily distributed in the range of 0-100 hPa,while the remaining 42.85%of outliers are evenly distributed in the range of 100-1000 hPa.The abnormal points,where the absolute value of temperature increment within the range of 0-100 hPa is greater than 10℃,are caused by factors such as solar radiation affecting the temperature sensor,which exceed the normal detection error range.These abnormal points can be removed in advance before quality control,further improving the quality of radiosonde temperature data.
作者
汪学渊
丘祖京
徐竹泉
WANG Xueyuan;QIU Zujing;XU Zhuquan(Fujian Key Laboratory of Severe Weather,Fuzhou 350007;Support Center for Atmospheric Observation Technology in Fujian,Fuzhou 350007;Longyan Meteorological Bureau,Fujian,Longyan 361006)
出处
《气象科技》
2023年第5期629-638,共10页
Meteorological Science and Technology
基金
福建省自然科学基金(2021J011256)资助。
关键词
探空温度
质量控制
参数优化
radiosonde temperature
quality control
parameter optimization
