Vaisala RS92/90 探测仪的湿度观测偏差订正初步试验

探空观测资料无论在天气预报还是数值预报中都是最基本和最重要的一类资料源。Vaisala RS92/90探测仪资料又在这类观测中占比很大,其湿度观测资料质量的好坏直接影响同化分析和降水预报,故需要对该资料进行质量评估与偏差订正。通过与NCEP和EC再分析的湿度场比较,发现Vaisala RS92/90探测仪的湿度观测偏差,借鉴Yoneyama et al(2008)对该仪器湿度观测的偏差订正方案,从几种订正方案中优选出对分析改进最为显著、考虑太阳辐射等因素影响的订正方案,并将该方案应用到GRAPES-GFS准业务试验中。试验结果表明:Vaisala RS92/90探空湿度观测偏差订正后,同化分析与预报有中性偏正效果。连续试验中订正后预报距平相关在东亚与热带有改进,预报评分显示热带、北半球评分略有提高。该订正方案在实际业务中有其应用价值。

A Preliminary Test for the Correction of the Humidity Observation Deviation of the Vaisala RS92/90 Detector

Sounding observation data are the most basic and important data source in weather forecast and numerical weather prediction. Vaisala Radiosonde 92/90 data account for a large proportion of this kind of observation. The quality of the humidity observation data directly affects the assimilation analysis and model forecast, so it is necessary to evaluate the quality of the data and correct the deviation. The humidity observation deviation of RS92/90 detector is found by comparing the humidity field of NCEP with EC reanalysis. Based on the deviation correction scheme of Yoneyama et al (2008) for the humidity observation of the instrument, the revised scheme, which is the most significant for the analysis and improvement and takes into account the influence of solar radiation and other factors, is selected from the comparison of several revised schemes. The scheme is applied to GRAPES-GFS test. The experimental results show that after the deviation of humidity observation for the RS92/90 sounding is corrected, the assimilation analysis and prediction have neutral effect. After the correction of prediction anomaly correlation in continuous experiments, there is an improvement in East Asia and the Tropics. The forecast score is slightly improved in these areas, so the correction scheme of humidity observation deviation of RS92/90 sounding instrument has its application value in practical operation.