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中国地面相对湿度非均一性检验及订正 总被引:4,自引:0,他引:4
利用加拿大环境部气候研究中心研发的PMTred和PMFT方法,选取均一的邻近站为参考站,使用相关系数权重平均构建参考序列,结合元数据信息,对1951-2014年中国2400多个国家级地面站月平均相对湿度进行了非均一性检验与订正,并分析了造成相对湿度序列非均一的主要原因。结果表明,中国地面相对湿度资料存在较严重的非均一问题,68%的台站存在断点,人工观测转自动观测、迁站和时次变化是造成序列非均一的主要原因。整套资料负订正量所占比例较高,订正范围主要集中在-5%~0之间,这种负订正量与人工转自动观测后相对湿度观测值偏低有密切关系。这也使得订正后中国平均相对湿度趋势与订正前存在明显差异,订正前中国平均相对湿度呈下降趋势,订正后相对湿度没有趋势性变化。 相似文献
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Comparison of two homogenized datasets of daily maximum/mean/minimum temperature in China during 1960–2013 下载免费PDF全文
Two homogenized datasets of daily maximum temperature (Tmax), mean temperature (Tm), and minimum temperature (Tmin) series in China have recently been developed. One is CHTM3.0, based on the Multiple Analysis of Series for Homogenization (MASH) method, and includes 753 stations for the period 1960–2013. The other is CHHTD1.0, based on the Relative Homogenization test (RHtest), and includes 2419 stations over the period 1951–2011. The daily Tmax/Tm/Tmin series at 751 stations, which are in both datasets, are chosen and compared against the raw dataset, with regard to the number of breakpoints, long-term climate trends, and their geographical patterns. The results indicate that some robust break points associated with relocations can be detected, the inhomogeneities are removed by both the MASH and RHtest method, and the data quality is improved in both homogenized datasets. However, the differences between CHTM3.0 and CHHTD1.0 are notable. By and large, in CHHTD1.0, the break points detected are fewer, but the adjustments for inhomogeneities and the resultant changes of linear trend estimates are larger. In contrast, CHTM3.0 provides more reasonable geographical patterns of long-term climate trends over the region. The reasons for the differences between the datasets include: (1) different algorithms for creating reference series for adjusting the candidate series—more neighboring stations used in MASH and hence larger-scale regional signals retained; (2) different algorithms for calculating the adjustments—larger adjustments in RHtest in general, partly due to the individual local reference information used; and (3) different rules for judging inhomogeneity—all detected break points are adjusted in CHTM3.0, based on MASH, while a number of break points detected via RHtest but without supporting metadata are overlooked in CHHTD1.0. The present results suggest that CHTM3.0 is more suitable for analyses of large-scale climate change in China, while CHHTD1.0 contains more original information regarding station temperature records. 相似文献
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基于1951—2014年2400余个中国国家级地面气象站均一化相对湿度资料,采用薄盘样条法,进行空间内插,得到了中国地面均一化相对湿度月值0.5°×0.5°格点数据集(CR数据集)。数据集的质量评估结果表明:冬季插值误差相对夏季偏高。冬、春、夏、秋季分析值与站点实测值的插值偏差空间区域特征不显著,平均偏差分别为0.002%/月、0.013%/月、0.008%/月和0.007%/月。冬、春、夏、秋季平均相对误差分别为0.431%/月、0.439%/月、0.286%/月和0.382%/月。分析值与站点实测值间的平均相关系数达0.89。整体来看,插值后的格点化相对湿度资料能够比较准确、细致地描述我国年平均相对湿度场的东南湿、西北干的主要空间特征。能够较好地展现长江以南地区、黄河以南长江以北地区、西北地区、天山南北麓、塔里木盆地等大地形的相对湿度变化特征。由于青藏高原台站稀少,格点数据集对该地区空气相对湿度特征的刻画是否合理很难给出定性、定量的判断。通过对CR数据集进行长时间序列气候变化趋势分析,表明60年来全国平均相对湿度呈减小趋势。 相似文献
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