The role of High Latitude Dust in changing climate: Severe dust storm observations in Iceland and Antarctica in 2020-2021

High Latitude Dust (HLD) contributes 5% to the global dust budget and active HLD sources cover > 500,000 km². Potential areas with high HLD emission are calculated to cover >1 670 000 km² (Meinander et al., in review). In Iceland, desert areas cover about 44,000 km², but the hyperactive dust hot spots of area < 1,000 km² are the most dust productive sources. Recent studies have shown that Icelandic dust travelled about 2,000 km to Svalbard and about 3,500 km to Balkan Peninsula. It estimated that about 7% of Icelandic dust can reach the high Arctic (N>80°). HLD was recognized as an important climate driver in Polar Regions in the IPCC Special Report on the Ocean and Cryosphere in a Changing Climate in 2019.

Long-term dust in situ measurements conducted in Arctic deserts of Iceland and Antarctic deserts of Eastern Antarctic Peninsula in 2018-2021 revealed some of the most severe dust storms in terms of particulate matter (PM) concentrations. While one-minute PM₁₀ concentrations is Iceland exceeded 50,000 μgm^-3, ten-min PM₁₀ means in James Ross Island, Antarctica exceeded 120 μgm^-3. The largest HLD field campaign was organized in Iceland in 2021 where 11 international institutions with > 70 instruments and 12 m tower conducted dust measurements (Barcelona Supercomputing Centre, Darmstadt, Berlin and Karlsruhe Universities, NASA, Czech University of Life sciences, Agricultural University of Iceland etc.). Preliminary results will be shown.

Icelandic dust has impacts on atmosphere, cryosphere, marine and terrestrial environments. It decreases albedo of both glacial ice/snow as well as mixed phase clouds via reduction in supercooled water content. There is also an evidence that volcanic dust particles scavenge efficiently SO₂ and NO₂ to form sulphites/sulfates and nitrous acid. High concentrations of volcanic dust and Eyjafjallajokull ash were associated with up to 20% decline in ozone concentrations in 2010. In marine environment, Icelandic dust with high total Fe content (10-13 wt%) and the initial Fe solubility of 0.08-0.6%, can impact primary productivity and nitrogen fixation in the N Atlantic Ocean, leading to additional carbon uptake.

There is also first HLD operational dust forecast for Icelandic dust available at the World Meteorological Organization Sand/Dust Storm Warning Advisory and Assessment System (WMO SDS-WAS) at https://sds-was.aemet.es/forecast-products/dust-forecasts/icelandic-dust-forecast. In 2020-2021, a total of 71 long-range dust events was identified from Iceland reaching Faroe Islands, United Kingdom, Ireland, and Scandinavia. HLD research community is growing and Icelandic Aerosol and Dust Association (IceDust) has 100 members from 47 institutions in 18 countries (https://icedustblog.wordpress.com, including references to this abstract).

 

Reference

Meinander, O., Dagsson-Waldhauserova, P., et al.: Newly identified climatically and environmentally significant high latitude dust sources, Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-963, in review, 2021.