Overview >

Tracking Air Pollution in China (TAP) is a near real-time air pollutant concentration database, which is developed and maintained by Tsinghua University in collaboration with Peking University, Nanjing University, Fudan University, Chinese Academy of Meteorological Sciences, etc. The TAP database is derived by machine learning approaches that combine information from multiple data sources, including ground measurements, satellite retrievals, emission inventories, chemical transport model simulations, meteorological fields and land use data. The TAP aims to provide near real-time air pollutant concentration data with complete spatiotemporal coverage and multiple spatial resolution and share that data with the scientific community through the cloud-computing platform, thus support the research on air pollution health effects and clean air policy assessment as well as environmental management.

Objective >

Human activities led to increased emission of various pollutants into the atmosphere that changed the content of the atmosphere and affected population health as well as climate. Accurately quantification of atmospheric composition is critical for research on air pollution, climate change, and environmental health. However, traditional atmospheric composition data from single sources could rarely meet the requests of high resolution, complete spatiotemporal coverage and long historical records. For example, the most accurate measurements from ground monitoring stations covers limited locations during limited time periods; the spatiotemporally continuous simulations from chemical transport models have nonnegligible uncertainties, and the satellite retrievals with broad coverage and long historical records cannot directly reflect ground air pollutant concentrations and have missingness. Thus, research on data fusion is urgently needed to develop a high-accuracy real-time atmosphere content database with full coverage and long-term continuous historical record.

Based on machine learning algorithms and multi-source information, the TAP team developed a data fusion system that integrates ground measurements, satellite remote sensing retrievals, emission inventories, air quality model simulations and other information. This data fusion system improves the accuracy of atmospheric aerosol retrieval in space and time. With the support of this technical system, the TAP team provides the Tracking Air Pollution in China (TAP) database that integrates the strengths of various data sources to provide atmospheric composition concentration estimations with complete-coverage on a daily scale. We further integrated cloud computing and big data technology to provide real-time dynamic calculation and online customized data download. At present, the TAP database has released 10-km fine particulate matter and major chemical composition concentration data in China from 2000 to the present, 1-km fine particulate matter concentration data in China from 2000 to the present, and ozone concentration data in China from 2013 to the present. More species and higher-resolution data will be shared with the scientific community in the future.

Against the background of continuous progress in observation capability and numerical simulation technology, the type and quantity of atmospheric composition data are rapidly increasing. How to better fuse data from multiple sources to achieve near real-time high-precision inversion of atmospheric composition is the main direction of concern for the TAP team in the future. We will continue to explore at the frontier and innovate algorithms while relying on the TAP website to share the research results with the scientific community, striving to provide more abundant, more precise, and more accurate atmospheric composition data products.

Features >

  • Include multiple air pollutants (i.e., PM2.5, PM2.5 chemical composition, and O3 for now and more in the future)
  • Developed with consistent methodology and data sources, version management, continuously update
  • Provide daily near real-time data products through cloud computing and big data methods
  • Integrate the real-time MEIC emission inventory and WRF/CMAQ simulations to achieve complete coverage of daily data;
  • Provide visual data analysis, customized data download and customized map download

Acknowledgements >

The development and maintenance of the TAP database is sponsored by:

  • National Natural Science Foundation of China
  • State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex
  • Ministry of Education Key Laboratory for Earth System Modelling