News 27.10.2023

The first systematic data on Saharan, Aral-Caspian and Middle East dust travels to Finland in 1980-2022

Long-range transported mineral dust has a wide range of direct and indirect effects as a climate-forcer, pollutant and nutrient. In a recent Environment International -journal publication, the first systematic long-term data for dust storm events from lower latitudes reaching the Finnish atmosphere was presented.
Sand dunes in the Saharan desert. Photo: Adobe Stock

The work utilized MERRA-2 satellite data, meteorological observations, and modelling results. In total, 86 long-range dust transport events were identified between 1980 and 2022, when air masses loaded with dust reached Finland.

Based on backward-trajectories different sources were identified: 59 were Saharan, 22 were Aral-Caspian, and five were associated with Middle Eastern source areas.

There is a clear maximum of dust events in spring (60 %), followed by summer and autumn, where 10 of the 11 autumn episodes were from the Sahara. However, the number and proportion of scarce winter events have more than doubled since 2010 compared to the preceding 30 years.

Next, researchers will investigate dust sources and impacts in more detail

A new IBA-ILMA project (2023-2025), lead by the Finnish Meteorological Institute and financed by the Ministry for Foreign Affairs of Finland, is expected to give an update to these first estimates using, e.g., more detailed SILAM model calculations.

In addition to desert dust, IBA-ILMA project also includes street and mining dust and the impacts of dust on ecology and health. These studies are carried out by the Finnish Environment Institute Syke; University of Helsinki Institute for Atmospheric and Earth System Research INAR; University of Helsinki, Department of Geosciences and Geography; and the Arctic Centre of the University of Lapland.

Further information:

Outi Meinander, Finnish Meteorological Institute, IBA-ILMA project leader,

The scientific article is available in Environment International.

Reference: Varga G, Meinander O, Rostási Á, Dagsson-Waldhauserova P, Csávics A, Gresina F. Saharan, Aral-Caspian and Middle East dust travels to Finland (1980-2022). Environ Int. 2023 Oct;180:108243. doi: 10.1016/j.envint.2023.108243. Epub 2023 Sep 29. PMID: 37804716, 2023.

The graph illustrates that the majority of long-range transported desert dust originates from the Sahara.
Area-averaged dust column mass density and the verified dust events in Finland from 1980 to 2022. Source: Varga et al. 2023.