While significant strides have been made in improving air quality in China through regulations like the Clean Air Act issued in 2013, air pollution has become increasingly complex. Despite notable improvements, the development of the economy and expansion of vehicular activity have given rise to new challenges, such as the emergence of ozone (O₃) pollution, complicating the landscape of air quality management.

In response, a dedicated air pollution data center has been launched, supported by a Major Research Plan of National Natural Science Foundation of China (NSFC) titled "Fundamental Researches on the Formation and Response Mechanism of the Air Pollution Complex in China." This initiative aims to delve into the formation mechanisms of air pollution, crucial chemical and physical processes, and their interconnectedness.

This Major Research Plan, comprising 76 individual research projects, has yielded extensive and high-quality data. To consolidate and disseminate these findings for the benefit of scientific research on air pollution, a comprehensive data sharing platform was initiated in 2020.

Spearheaded by Peking University, in collaboration with Tsinghua University, the Institute of Atmospheric Physics of the Chinese Academy of Sciences, Beijing Normal University, and 3Clear Science & Technology Co., Ltd., this platform marks the inception of the China Air Pollution Data Center (CAPDC).

Accessible at www.capdatabase.cn, CAPDC represents the first-ever data sharing platform focused specifically on atmospheric pollution complexities in China. Designed to be inclusive, the platform welcomes both domestic and international scientists.

The introduction of CAPDC has been featured in the journal Advances in Atmospheric Sciences, categorizing the results from the Major Research Plan into eight distinct categories, encompassing both data and non-data types. The data categories include emission inventory, chemical reanalysis, field observation, satellite observation, laboratory measurement, and source profile, comprising a total of 258 datasets. Non-data type results are further divided into new technology and online source apportionment technology, totaling 15 reports.

Here's a brief overview of some key data categories available on CAPDC:

1. Emissions Inventory: Providing nine datasets covering various anthropogenic and natural sources, including a 10-km resolution emission inventory for China in 2017.
2. Chemical Reanalysis: Comprising three datasets, including high-resolution air quality reanalysis and PM_2.5 composition data, continuously updated on the platform.
3. Field Observation: Offering 221 datasets from 2011 to 2021, capturing field measurements in 41 cities, focusing on parameters such as cloud characteristics and aerosol parameters.
4. Satellite Observation: Collating high-resolution data for various atmospheric pollutants through the Major Research Plan and the ChinaHighAirPollutants (CHAP) dataset.
5. Laboratory Measurement: Encompassing physicochemical property parameters and chemical reaction parameters across six datasets.

The CAPDC website provides bilingual access in Chinese and English, facilitating functions such as project information inquiries, data retrieval, and downloading after registration and agreement to the data use terms. Notably, emissions inventory, chemical reanalysis, and satellite observation data can be previewed prior to downloading.

"Looking ahead, CAPDC aims to expand its repository with additional data and resources, continually enhancing user experience and bolstering efforts in combating air pollution." Said the PI of CAPDC, Prof. Mei Zheng from Peking University.