Construction of homogenized daily surface air temperature for the city of Tianjin during 1887–2019

Century-long continuous daily observations from some stations are important for the study of long-.term trends and extreme climate events in the past. In this paper, three daily data sources –(1) the Department of.IndustryAgencyoftheBritishConcessioninTianjincovering1September1890–31December1931,(2)theWa-.ter Conservancy Commission of North China covering 1 January 1932–31 December 1950 and (3) monthly jour-.nal sheets for Tianjin surface meteorological observation records covering 1 January 1951–31 December 2019.– have been collected from the Tianjin Meteorological Archive. The completed daily maximum and minimum.temperature series for Tianjin from 1 January 1887 (1 September 1890 for minimum) to 31 December 2019 has.been constructed and assessed for quality control with an early extension from 1890 back to 1887. Several sig-.nificant breakpoints are detected by the penalized maximal T test (PMT) for the daily maximum and minimum.time series using multiple reference series around Tianjin from monthly Berkeley Earth (BE), Climatic Research.Unit Time-Series version 4.03 (CRU TS4.03) and Global Historical Climatology Network (GHCN) v3 data. Us-.ing neighboring daily series the record has been homogenized with quantile matching (QM) adjustments. Based.on the homogenized dataset, the warming trend in annual mean temperature in Tianjin averaged from the newly.constructed daily maximum and minimum temperature is evaluated as 0.154±0.013 ◦ C per decade during the.last 130 years. Trends of temperature extremes in Tianjin are all significant at the 5% level and have much.more coincident change than those from the raw data, with amplitudes of −1.454, 1.196, −0.140 and 0.975d.per decade for cold nights (TN10p), warm nights (TN90p), cold days (TX10p) and warm days (TX90p) at the.annual scale.

一些站点长达一个世纪的连续每日观测对于研究过去的长期趋势和极端气候事件非常重要。本文从天津气象档案馆收集了三个每日数据源：（1）1890年9月1日至1931年12月31日的天津英租界工部局数据；（2）1932年1月1日至1950年12月31日的华北水利委员会数据；（3）1951年1月1日至2019年12月31日的天津地面气象观测记录月报表。构建了1887年1月1日（最低温度为1890年9月1日）至2019年12月31日天津完整的每日最高和最低温度序列，并进行了质量控制评估，其中早期从1890年延伸回1887年。利用来自伯克利地球（BE）月数据、气候研究单位时间序列4.03版（CRU TS4.03）和全球历史气候学网络（GHCN）v3数据的天津周边多个参考序列，通过惩罚性最大T检验（PMT）检测到每日最高和最低温度序列的几个显著断点。利用邻近的每日序列，通过分位数匹配（QM）调整对记录进行了均一化。基于均一化数据集，在过去130年中，由新构建的每日最高和最低温度平均得到的天津年平均温度的变暖趋势估计为每十年0.154±0.013℃。天津极端温度的趋势在5%的水平上均显著，且比原始数据的变化更为一致，在年尺度上，冷夜（TN10p）、暖夜（TN90p）、冷天（TX10p）和暖天（TX90p）每十年的变化幅度分别为 -1.454、1.196、 -0.140和0.975天。