Press Summary: 
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The 2023 award winner, Dr. Lubna Dada from the Paul Scherrer Institute in Villigen
(pictured with the President of the Prize Committee, Prof. Barbara Rothen)
presented her important work in Bern on November 15, 2023:
On a research ship in the Arctic in April 2020, she observed an extreme weather and air pollution event with a temperature rise of 30 degrees C and with many smoke particles from coal-fired power plants in Russia and China, which were and will continue to be responsible for the rapid melting of the polar ice and also the extreme weather events here.
A central arctic extreme aerosol event triggered by a warm air-mass intrusion
At the Extreme Environments Research Laboratory, EPF Sion, measurements in the central Arctic Ocean, on board of the icebreaker research vessel Polarstern, revealed the extent of aerosol pollution arriving into the central Arctic from mid-latitudes. This phenomenon has serious implications for the Arctic climate since the transported aerosol particles could act as cloud seeds, forming a blanket-like structure with warming properties and accelerating the Arctic amplification process and the Arctic sea ice melt. The results also show how high concentrations of anthropogenic air pollution reach sensitive ecosystems where no noticeable local pollutant emissions are observed. The work highlights the importance of transboundary global efforts in reducing air pollutants especially in the context of global warming. This work was shown by Lubna Dada and was awarded the Swiss Aerosol Award 2023
The Arctic is warming at a rate roughly four times as fast as the rest of the globe due to Arctic amplification. While its detailed causes remain to be quantified, a large number of studies attributed the amplification to anomalous poleward atmospheric transport in the form of warm air-mass intrusions from mid-latitudes. With a changing climate, these intrusions of warm and moist air into the Arctic have become more frequent and intense over the past decades, and they have been identified as a key factor in the rapid melting of Arctic sea ice. During the year-long MOSAiC expedition in the remote central Arctic Ocean aboard the research vessel Polarstern, an extreme event occurred in mid-April 2020, associated with an increase of air temperature by 30oC in less than 48 hours. This event witnessed a remarkable surge in moisture levels, and longwave radiation, all attributed to an air-mass intrusion carrying air pollutants from northern Eurasia.
The two-day intrusion, caused drastic changes in the aerosol size distribution, chemical composition and particle hygroscopicity. The aerosol particles were found to have traveled from lower latitudes undergoing transformations allowing them to modify the Arctic cloud regime (and thereby energy budget) and depleting gas phase constituents critical for the biogeochemical cycle in the Arctic climate. Such an observation was first of a kind, given the minimal measurements of chemical properties of aerosol particles in the central Arctic Ocean.
The awarded research showcases how the intrusion altered the Arctic environment, transforming it from a remote, unpolluted setting into a region resembling an urban area in central Europe. Furthermore, it highlights the impact of this transformation on the Arctic climate. For instance, the intrusion led to a substantial increase in cloud condensation nuclei, which can directly influence various aspects of Arctic clouds, including their radiation properties, precipitation patterns, and longevity. This study highlights the need of integrating aerosol research and in-situ measurements with meteorological and atmospheric transport investigations to identify the most effective strategies for mitigating these "natural" yet pollution-driven events. Given the multitude of ongoing Arctic climate research initiatives, particularly in response to the pressing issue of global warming, the findings of this work are relevant to many researchers and policymakers. It constitutes a valuable contribution to one of the most urgent research topics of our time: climate change.
This research suggests that taking prompt actions to significantly reduce emissions in the source regions is necessary to reduce the impact of these events on the Arctic climate. The Swiss Aerosol Award will be/was presented on 15 November 2023 at the 18th meeting of the Swiss Aerosol Group (SAG).
The prize is endowed with CHF 5 000.
Information:
- Dr. Lubna Dada, Scientist, Atmosphere-Biosphere Interactions Group, Laboratory of Atmospheric
Chemistry, Paul Scherrer Institute, Villigen,
Original title: A central arctic extreme aerosol event triggered by a warm air-mass intrusion; Quelle:
https://www.nature.com/articles/s41467-022-32872-2