Global Annual PM2.5 Grids from MODIS, MISR and SeaWiFS Aerosol Optical Depth (AOD), 1998-2021, V5.GL.03

The Global Annual PM2.5 Grids from MODIS, MISR and SeaWiFS Aerosol Optical Depth (AOD), 1998-2021, V5.GL.03 consists of annual concentrations (micrograms per cubic meter) of all composition ground-level fine particulate matter (PM2.5). This data set combines AOD retrievals from multiple satellite algorithms including the NASA MODerate resolution Imaging Spectroradiometer Collection 6.1 (MODIS C6.1), Multi-angle Imaging SpectroRadiometer Version 23 (MISRv23), MODIS Multi-Angle Implementation of Atmospheric Correction Collection 6 (MAIAC C6), and the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) Deep Blue Version 4. The GEOS-Chem chemical transport model is used to relate this total column measure of aerosol to near-surface PM2.5 concentration. Geographically Weighted Regression (GWR) is used with global ground-based measurements from government agencies, literature-based observations, the World Health Organization Global Ambient Air Quality Database, and OpenAQ to predict and adjust for the residual PM2.5 bias per grid cell in the initial satellite-derived values. These estimates are primarily intended to aid in large-scale studies. Gridded data sets are provided at a resolution of 0.01 degrees to allow users to agglomerate data as best meets their particular needs. Data sets are gridded at the finest resolution of the information sources that were incorporated, but do not fully resolve PM2.5 gradients at the gridded resolution due to influence by information sources at coarser resolution. The data are distributed as netCDF and GeoTIFF files and are in WGS84 projection.

The data are available as both netCDF (.nc) and GeoTIFF (.tif) files by year in unprojected WGS84 geographic coordinate system (GCS). The netCDF ile sizes range from 97 MB to 114 MB and the GeoTIFF files range from 210 to 220 MB. A readme.txt file describes how the netCDF files were converted to GeoTIFF.

A detailed description of the methodology that forms the foundation of this data is available from the peer-reviewed open access paper below:

van Donkelaar, A., M. S. Hammer, L. Bindle, M. Brauer, J. R. Brook, M. J. Garay, N. C. Hsu, O. V. Kalashnikova, R. A. Kahn, C. Lee, R. C. Levy, A. Lyapustin, A. M. Sayer and R. V. Martin (2021). Monthly global estimates of fine particulate matter and their uncertainty. Environmental Science & Technology, 2021, https://doi.org/10.1021/acs.est.1c05309.

van Donkelaar, A., M. S. Hammer, L. Bindle, M. Brauer, J. R. Brook, M. J. Garay, N. C. Hsu, O. V. Kalashnikova, R. A. Kahn, C. Lee, R. C. Levy, A. Lyapustin, A. M. Sayer and R. V. Martin (2023). Global Annual PM2.5 Grids from MODIS, MISR and SeaWiFS Aerosol Optical Depth (AOD), (1998-2021), V5.GL.03 (Preliminary Release). Palisades, NY: NASA Socioeconomic Data and Applications Center (SEDAC). https://doi.org/10.7927/bz7m-wq98. Accessed DAY MONTH YEAR.

This is a preliminary open data release, pending peer review of the data and associated journal articles. Following the peer review process, data curation will be completed by the NASA Socioeconomic Data and Applications Center (SEDAC) and the data will be disseminated through the SEDAC catalog.