In-situ aerosol measurements in Iceland, Antarctica and Svalbard in 2024, including plumes of High Latitude Dust and Saharan Dust, and Black Carbon haze

Polar Regions are the most fragile regions on our Earth, where small changes can have tremendous impacts on local and global climate. Black Carbon and High Latitude Dust (HLD) were recognized as important climate drivers in Polar Regions (AMAP, 2015; IPCC SROCC, 2019). HLD has impacts on climate, such as effects on cryosphere, cloud properties, atmospheric chemistry and radiation, and marine environment.  

In 2024, many extreme events causing severe air pollution were observed and measured in Iceland, Svalbard and Antarctica. In Iceland, we measured i. tens of severe dust storms at multiple locations, resulting in long-range transport to Scandinavia, Faroe and British Isle, and Svalbard; ii. two Saharan dust plumes causing air pollution in Iceland, and iii. Black/Organic Carbon haze from burning mosses around the eruption in Reykjanes Peninsula, transported >300 km to Northeast Iceland. Several dust storms were measured also in Antarctic Peninsula. In Svalbard, aerosol measurements revealed high concentrations of dust, coal dust and Black Carbon, while dirty snow evidenced the occurrences of Snow-Dust Storms, similarly to Iceland.        

The 2024 HLD measurements are part of the long-term in-situ measurements conducted occasionally in deserts of Iceland since 2013 and Antarctic deserts of Eastern Antarctic Peninsula since 2018. Severe Icelandic dust storms exceeded particulate matter (PM) concentrations (one-minute PM₁₀) of 50,000 ugm^-3 in the past. However in 2024, the instruments were overloaded (maximum concentration 150 mgm^-3) several times. Antarctic summer was not as severe as in 2021-2022 when hourly PM₁₀ means in James Ross Island exceeded 300 ugm^-3. Saharan dust plumes in Iceland caused increase of PM₁₀ (PM_2,5) concentrations to 200 (50-100) ugm^-3 in November 2024.

The August 2024 eruption in Reykjanes Peninsula in Iceland caused a biomass burning haze at locations > 300 km with significantly reduced visibility and smoke smell. The cause was burning mosses around the fresh lava. Air pollution in terms of Black Carbon (BC) concentrations was severe. Particle number concentrations of Black Carbon increased from background of 0-10 particles per cm³ to 10 000 particles per cm³. Some particles exceeding the sizes > 1 µm. Particulate matter (PM₁) mass concentrations had exceeded 25 µgm^-3 for 12 hours. These HLD and BC events were not captured by most of the models or remote sensing products except for the DREAM and SILAM models.

The year 2024 was extreme in terms of variability and frequency of air pollution events in Iceland. The air pollution observed in Longyearbyen, Svalbard, seems to be common based on the industrial background of the town. Long-term daily aerosol measurements are therefore needed at more locations at high latitudes than available. More in-situ observations around HLD sources would confirm that background air quality is not better than at industrial or some urban stations, such as in Iceland during the CAMS NCP project.

More information at the Icelandic Aerosol and Dust Association (IceDust) websites (https://ice-dust.com/, https://icedustblog.wordpress.com/publications/), UArctic Network on High Latitude Dust (https://www.uarctic.org/activities/thematic-networks/high-latitude-dust/), NORDDUST (https://ice-dust.com/projects/norddust/), and CAMS NCP Iceland (https://ice-dust.com/projects/cams-ncp-iceland/, https://atmosphere.copernicus.eu/iceland). Field campaigns were partially funded by Orkurannsoknasjodur, National Power Agency of Iceland.