对温度观测资料进行质量控制时，僵值和突变是常见的疑误类型，针对城市复杂环境中僵值和突变疑误数据进行研究，对降低城市自动站温度资料质量控制的误检率有重要价值。文章针对城市复杂环境（以上海世博园为例）中18个自动气象站一年（2010年5月至2011年4月）逐时温度资料进行质量控制，着重探讨僵值及突变疑误数据的分布特征和可能原因。结果表明：（1）僵值疑误数据集中出现在冬季夜间，局地性强。阴天或多云天气，通风不佳的测站感热项较小，易出现僵值过程，最长持续11 h。（2）温度突变疑误数据可分“突升”和“突降”两类，“突升”集中出现在秋冬季，而“突降”集中在春夏季；“突升”集中出现在日出前后，而“突降”主要出现在午后至夜晚，“突升”局地性强而“突降”各站间趋同性较强。分析发现，城市复杂环境下，日照突然增加或减少以及午后短时强降水是导致温度突变疑误数据的主要原因。因此，这些“疑误”数据是城市复杂环境影响或特定天气条件导致的，为真实有效的观测资料。针对城市复杂环境下的温度观测资料开展质量控制时，需结合观测环境等元数据进一步甄别。%Temperature observations,especially those observations from highly urbanized areas,are most likely to fail persistence test and step test when basic quality assurance (QA)procedures are applied.Ac-cording to WMO,doubtful data from the persistence test and the step test are called dead band suspected data and inconsistent suspected data.Studying these suspected observations may contribute to validating important doubtful data and improving the performance of temperature QA system.Basic QA procedures are applied to hourly temperature observations at 18 automatic weather stations in a highly urbanized area (Shanghai Expo)collected from May 2010 to April 2011.The distribution of suspected data and possible causes are investigated.The results show that temperature dead band suspected cases occur mostly at iso-lated stations in the winter evening.They are more likely observed at shielded and blocked stations in cloudy weather.The sensible heat flux is low in these situations,which may be the reason that tempera-ture keeps the same value for several hours,even lasting for 11 h at most.In addition,the temperature in-consistent suspected cases can be grouped into two subsets:temperature jump cases and temperature slump cases.The temperature jump cases mostly occur around sunrise in autumn and winter while the slump cases mainly are found in the afternoon or evening of spring-summer season.Moreover,the temperature jump cases appear at isolated stations,but temperature slump cases co-occur at different observing sites. The occurrence of these cases is closely related to weather conditions.As solar altitude increases at sunrise,the sheltered stations are suddenly exposed to the sun and warm up dramatically.Similarly,temperature goes down rapidly around sunset at the sheltered stations and temperature slump cases occur.In addition,the short-time heavy precipitation also causes dramatically cooling at stations.Therefore,these suspected data are reasonable. They might be important observations in studying extreme weather events as well as environment effects on tem-perature.Multiple cross-checks are required when some samples fail in the basic QA test.
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