Dutch space instrument SPEXone produces world map of aerosols

On February 8, 2024, NASA launched its PACE climate satellite with the Dutch aerosol instrument SPEXone onboard. A full year of observations now yields a world map of aerosols.

It shows the distribution of fine and coarse aerosols and of particles that reflect or absorb sunlight. The latter respectively have cooling and warming effects on the climate. SPEXone was built by SRON and Airbus Netherlands, with support from TNO. Aerosols are small particles in the atmosphere such as soot, ash and desert dust , also called particulate matter. They have a net cooling effect on the climate, but to what extent is unclear. The estimate ranges from 0.2 to as much as 0.9 degrees, dampening the influence on global warming .

Aerosols affect the climate both directly via reflection and absorption of sunlight, and indirectly by acting as condensation cores for cloud formation. For example, the lack of low-level cloud cover is one of the causes of the record warm year of 2024. World map After a year in space, SRON's SPEXone team has now produced three global aerosol maps. The first shows the distribution of aerosols across Earth's atmosphere. The second map shows the amount of fine aerosols relative to the total number of both fine and coarse aerosols. Here, it can be seen that fine particles mostly occur above areas with a lot of traffic and industry, such as India and regions with many fires, such as central Africa and Siberia.

World map of the amount of aerosol, shown as the Aerosol Optical Depth. The map shows the average value for each location on earth for the period March to December 2024. Credit: SRON Read more

World map of fine aerosols relative to total aerosols, including both fine and coarse. Deserts and oceans are clearly shown in blue because desert dust and sea salt are coarser aerosols. Regions with a lot of industry and traffic (e.g. India) and areas with a lot of fires (e.g. central Africa and Siberia) are red, because those processes produce finer particles. The map shows the average value for each location on earth for the period March to December 2024. Credit: SRON Read more

World map of the amount of reflective aerosols relative to the total amount of aerosols, including reflecting and absorbing. Reflecting aerosols (red) have a cooling effect. Absorbing aerosols (blue) have a warming effect. Smoke particles from forest fires absorb sunlight, which can be clearly seen in California, northern Siberia and central Africa. The map shows the average value for each location on earth for the period March to December 2024. Credit: SRON Read more