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

Abstract

Abstract. 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 Industry Agency of the British Concession in Tianjin covering 1 September 1890–31 December 1931, (2) the Water Conservancy Commission of North China covering 1 January 1932–31 December 1950 and (3) monthly journal 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 significant 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. Using 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 0.975 d per decade for cold nights (TN10p), warm nights (TN90p), cold days (TX10p) and warm days (TX90p) at the annual scale. The adjusted daily maximum, minimum and mean surface air temperature dataset for Tianjin city presented here is publicly available at https://doi.org/10.1594/PANGAEA.924561 (Si and Li, 2020).

HomogWS-se: a century-long homogenized dataset of near-surface wind speed observations since 1925 rescued in Sweden

“…These century-long, high-quality climate records created through data rescue and homogenization provide an essential baseline for the past climate (Yan et al, 2014;Capozzi et al, 2020;Si et al, 2021). These not only preserve the rich heritage of observers' diligent work in the past but also yield more robust assessments of climate variability and change, helping to make our societies more climatically resilient in the future.…”

The observed features and some possible reasons of annual temperature extremes over Beijing‐Tianjin‐Hebei region for a century long‐term based on newly constructed daily observations

“…The daily maximum and minimum temperature data for Beijing-Tianjin-Hebei region used in this research are the homogenized series produced by Si et al (2021aSi et al ( , 2022Si et al ( , 2023, with the beginning time of 1841 (1880 for the maximum data), 1887 (1890 for the minimum data) and 1912 severally for Beijing, Tianjin and Baoding city up to 2021. These records were firstly experienced procedures of quality control combined with manual judgement in the interest of removing or correcting some errors in manual observations, instrument malfunctions and digital inputs.…”

“…To this end, Si et al (2021aSi et al ( , 2022Si et al ( , 2023 has produced the homogenized daily surface air temperature for the cities of Beijing, Tianjin and Baoding over century-long timescale in order to better improve the construction method and daily data quality for a century-long timescale in China. In these researches, more complete metadata information and combinatorial homogenization technology based on daily observations in situ station have been used, so as to satisfy the needs of reliable longtime basic observations in the field of average climatology and extreme climate change during the recent years.…”

“…But so far there are less assessments of climate change and extreme events in urban areas on the timescale over a 100 years or more (IPCC, 2013). The possible reason is that it is difficult to form a complete global daily surface temperature dataset for a century-long timescale, due to the difficulties in collection and acquisition and some nonclimatic factors such as different observation times (Si et al, 2021a). Accordingly, it is of great significance for the healthy development of our social economy to reveal the characteristics of extreme climate change objectively and better understanding the attributions in Beijing-Tianjin-Hebei region over the past 100 years, especially before 1950.…”

“…In this paper, the observed characteristics and some possible attributions of extreme temperature in urban areas during the past 100 years will be estimated represented by Beijing-Tianjin-Hebei region, using the new series of daily maximum and minimum temperature observations in Beijing, Tianjin and Baoding cities (Si et al, 2021a(Si et al, , 2022(Si et al, , 2023. Thus, the application value of the limited and precious climate observations on long timescale in meteorological service guarantee and scientific innovation will be enhanced furtherly, and the scientific reference and new understanding also will be provided for strengthening the supporting ability of existing researches of extreme climate events in urban areas under the background of global warming on the social, ecological and economic sustainable development in China.…”