地基微波辐射计探测资料质量控制方法

微波辐射计具有24 h不间断工作、时间分辨率高等优点，是常规探空的有益补充。天线罩上的积水、无线电干扰等会导致微波辐射计探测数据出现错误。因此，开展质量控制是合理使用微波辐射计探测资料的基础。该文利用上海宝山站历史探空资料和世博园站MP-3000A型地基微波辐射计温湿度数据，设计了极值、时间一致性、空间一致性检查等适用于微波辐射计探测资料的质量控制方法，针对2012年1月-2013年12月降水、有云（有云无降水）、晴空等不同天气条件下得到的微波辐射计探测资料分别开展质量控制，并对质量控制效果进行定量分析。结果表明:上述方法能有效查找温（湿）度超过极值、温（湿）度突变、温度层际变化大等各类疑误廓线，疑误廓线类型和频数与天气条件有关，其中降水天气的各类疑误廓线频数远远高于无降水天气（有云和晴空）。去除疑误廓线后，与同期探空资料的相关系数增加，均方根误差减小。

Quality Control of Temperature and Humidity Profile Retrievals from Ground-based Microwave Radiometer

Ground-based microwave radiometer profiler (MWR) can continuously retrieve thermodynamic profiles of the atmosphere on a minute time scale. These profiles are important supplements to radiosonde observations. Since the presence of liquid water on the profiling radiometer, radio frequency interference and other events can cause errors, quality control procedures that can detect data-quality problems are of critical importance. QC procedures are proposed for ground-based MWR-retrieved atmospheric profiles of temperature and humidity using 10-year radiosonde soundings (January 2004 to December 2014) at Baoshan Station in Shanghai and observations from MP-3000A MWR (January 2012 to May 2014) at Shanghai Expo Station. QC procedures include three types of checks:Climatological test, time consistency test, and vertical consistency test. Climatological check aims to verify if the values of instantaneous data are within climatology range limits. Thresholds are set based on the seasonally varying statistics of 10-year radiosonde soundings. The time consistency check focus on the change rate of instantaneous data. If the difference between the current instantaneous value with the previous one exceeds a specific limit, the current value will be flagged as doubtful. The test is applied level by level, and the profile with suspected data at more than one level is flagged as doubtful. Vertical consistency checks operate on dT_h and contain two tests: A test for the plausible value check of dT_hand a test for the standard deviation of dT_h (σ (dT_h)). dT_h (unti:℃· (100 m)-1) is defined as the ratio of temperature difference to height difference at consecutive levels. The plausible value check of dT_h is proposed to verify if there are spikes in a profile. The test for (σ (dT_h)) is used to sort profiles with excessive level-to-level fluctuations throughout a sounding. Results show that QC methods can effectively identify various suspected observations, such as climatological outliers, temporal inconsistency and excessive vertical fluctuations in profiles. The frequency of suspected temperature and humidity profiles detected in rainy days is much higher than that in other weather conditions. The accuracy of MWR retrieved temperature and vapor density profiles is improved after applying these QC procedures. Correlation coefficients of both temperature and humidity observations between the MWR and radiosonde increase and corresponding root mean square error (RMSE) decrease after QC, especially those in rainy days. QC procedures for MWR-retrieved thermodynamic profiles are also proposed, through which various suspected profiles can be flagged. The accuracy of MWR retrievals is improved significantly after applying QC procedures.