文章基本信息

标题：A homogenized daily in situ PM2.5 concentration dataset from the national air quality monitoring network in China
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作者：Bai, Kaixu ; Li, Ke ; Wu, Chengbo 等
期刊名称：Earth System Science Data (ESSD)
印刷版ISSN：1866-3508
电子版ISSN：1866-3516
出版年度：2020
卷号：12
期号：4
页码：3067-3080
DOI：10.5194/essd-12-3067-2020
出版社：Copernicus
摘要：In situ PM2.5 concentration observations have long been used as critical data sources in haze-related studies. Due to the frequently occurring haze pollution events, China started to regularly monitor PM2.5 concentration nationwide from the newly established air quality monitoring network in 2013. Nevertheless, the acquisition of these invaluable air quality samples is challenging given the absence of a publicly available data download interface. In this study, we provided a homogenized in situ PM2.5 concentration dataset that was created on the basis of hourly PM2.5 data retrieved from the China National Environmental Monitoring Center (CNEMC) via a web crawler between 2015 and 2019. Methods involving missing value imputation, change point detection, and bias adjustment were applied sequentially to deal with data gaps and inhomogeneities in raw PM2.5 observations. After excluding records with limited samples, a homogenized PM2.5 concentration dataset comprising of 1309 5-year long PM2.5 data series at a daily resolution was eventually compiled. This is the first attempt to homogenize in situ PM2.5 observations in China. The trend estimations derived from the homogenized dataset indicate a spatially homogeneous decreasing tendency of PM2.5 across China at a mean rate of about −7.6 % per year from 2015 to 2019. In contrast to raw PM2.5 observations, the homogenized data record not only has complete data integrity but is more consistent over space and time.