NASANear real-time global composition forecasts of ozone, NO₂, CO, and fine particulate matter using the GEOS atmospheric model coupled with the GOCART chemistry module.
NASA
MERRA-2: Modern-Era Retrospective Analysis for Research
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NASA
The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2) is NASA's global atmospheric reanalysis produced by the Global Modeling and Assimilation Office (GMAO). It provides a consistent, continuous record of the atmosphere from 1980 to present at 0.5° latitude × 0.625° longitude resolution with 72 vertical levels.
MERRA-2 incorporates aerosol observations from AERONET, MODIS, and other sources through the GOCART aerosol module, making it particularly valuable for PM2.5 estimation in data-sparse regions. The dataset is widely used for long-term air quality trend analysis, climate studies, and model evaluation.
Learn more
Documentation, algorithm details, and background reading for MERRA-2.
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Access MERRA-2 through the provider portal or download it directly.
Tutorials
Self-paced tutorials to help you get started with MERRA-2.
Getting started with MERRA-2
An introduction to the MERRA-2 dataset — what it measures, how it is produced, and when to use it.
Accessing and downloading MERRA-2 dataFind, subset, and download MERRA-2 data, with tips for common file formats and access tools.
Exploring MERRA-2 in the AIR4US visualization toolLoad MERRA-2 layers in the AIR4US visualization tool and interpret them alongside other air quality data.
Cite this dataset
NASA GMAO. MERRA-2: Modern-Era Retrospective Analysis for Research. 1980 – Present. Accessed via the AIR4US Portal, https://gmao.gsfc.nasa.gov/reanalysis/MERRA-2.
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