Scientists from NOAA PSL and GSL release global aerosol dataset to assist with weather modeling

Aerosols, or tiny particles released to the atmosphere through various natural and human activities, play a key role toward understanding the Earth system. Every day, they impact air quality and human health, while also influencing our weather by affecting clouds and the amount of sunlight reaching the ground. However, it is difficult to track their global distribution and evolution because their direct measurements are sparse. As a result, aerosol modeling remains largely challenging.

To help fill that gap, scientists from the Cooperative Institute for Research in Environmental Studies (CIRES) working at NOAA’s Physical Sciences Laboratory (PSL) and Global Systems Laboratory (GSL) have released a new global dataset of aerosols: the NOAA Aerosol ReAnalysis (NARA) Version 1.1. This reanalysis provides a full global dataset of estimated aerosol distribution for five years (2018-2022), at 0.5-degree spatial resolution, at six-hour intervals.

A reanalysis combines observations of the past with modern weather forecast models to reconstruct past atmospheric conditions. It creates a picture of the weather as close to reality as possible. Complete reanalysis datasets are extraordinarily useful for many atmospheric science applications across the globe.

NARA v1.1 takes advantage of satellite observations, particularly aerosol optical depth (AOD) retrievals from the Visible Infrared Imaging Radiometer Suite (VIIRS) at NOAA Satellites. Using modern data assimilation techniques from the Joint Effort for Data Assimilation (JEDI), these data are combined with aerosol forecasts from the NOAA Global Chemistry and Aerosol Forecast System (GCAFS) that utilizes the state-of-the-art NASA Goddard Chemistry Aerosol Radiation and Transport (GOCART) model of characterizing aerosols in the atmosphere.

The release of NARA v1.1 provides a valuable new reanalysis resource for the scientific and operational community in support of weather and air quality research, model development and validation, and intercomparison with other global aerosol reanalyses. It includes the mass mixing ratios of fine, medium, coarse, and total dust and sea salt, hydrophobic and hydrophilic black and organic carbon, and sulfate. NARA v1.1 also closes a key gap in NOAA’s global aerosol reanalysis capability, aligning NOAA with other major research and operational centers such as NASA, the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Japan Meteorological Agency (JMA).

This project involved work at CIRES, GSL, and PSL. It was funded through the NOAA Weather Program Office under award NA22OAR4590219. Other collaborators include the Joint Center for Satellite Data Assimilation (JCSDA), the NESDIS Center for Satellite Applications and Research (STAR), and National Weather Service Environmental Modeling Center (EMC).

Posted: December 31, 2025
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