Homogenization of Chinese daily surface air temperatures and analysis of trends in the extreme temperature indices

Abstract

[1] This study first homogenizes time series of daily maximum and minimum temperatures recorded at 825 stations in China over the period from 1951 to 2010, using both metadata and the penalized maximum t test with the first-order autocorrelation being accounted for to detect change points and using the quantile-matching algorithm to adjust the data time series to diminish discontinuities. Station relocation was found to be the main cause for discontinuities, followed by station automation. The effects of discontinuities on estimation of long-term trends in the annual mean and extreme indices of temperature are illustrated. The data homogenization is shown to have improved the spatial consistency of estimated trends. Using the homogenized daily minimum and daily maximum temperature data, this study also analyzes trends in extreme temperature indices. The results show that the vast majority (85%-90%) of the 825 sites have experienced significantly more warm nights and less cold nights since 1951. There have also been more warm days and less cold days since 1951, although these trends are less extensive. About 62% of the 825 sites were found to have experienced significantly more warm days and about 50% significantly less cold days. None of the 825 sites were found to have significantly more cold nights/days or less warm nights/days. These indicate that the warming is stronger in nighttime than in daytime and stronger in winter than in summer. Thus, the diurnal temperature range was found to have significantly decreased at 49% of the 825 sites, with significant increases being identified only at 3% of these sites.

Multiscale Comparative Evaluation of the GPM IMERG v5 and TRMM 3B42 v7 Precipitation Products from 2015 to 2017 over a Climate Transition Area of China

“…The SURF_CLI_CHN_MUL_DAY_V3.0 dataset contains data from 824 benchmark and basic weather stations across the country, providing high quality information on precipitation since January 1951. All data were compiled by the National Meteorological Information Center and subjected to a series of quality controls, including examining extreme values and an internal consistency check, and removal of questionable data according to the methods described by Xu et al [32]. The locations of the rain gauges are shown in Figure 1. …”

Explaining Extreme Events of 2014 from a Climate Perspective

“…Homogenized daily temperatures at 2419 stations in China for the period 1951-2014 are available for this study (Xu et al 2013 …”

Homogenization of Tianjin monthly near-surface wind speed using RHtestsV4 for 1951–2014

“…These studies found that it is more accurate and easier to analyze meteorological elements based on time series where significant breakpoints have been removed (Winkler Julie et al 1981;Alexandersson 1986). In recent years, homogenized historical temperature and precipitation observations in China have been developed by Chinese meteorologists; these represent a breakthrough in homogenization of surface observations (Li et al 2009Xu et al 2013), but homogenizing other meteorological elements remains an open question. The lack of data has restricted data assimilation, prediction, and forecasting for climate change; accordingly, it is important to increase the number of homogenization products available for current meteorological data processing.…”