A central arctic extreme aerosol event triggered by a warm air-mass intrusion

• Published in: Nature Communications
• Main Authors: Dada, Lubna, Angot, Hélène, Beck, Ivo, Baccarini, Andrea, Quéléver, Lauriane, L J, Boyer, Matthew, Laurila, Tiia, Brasseur, Zoé, Jozef, Gina, de Boer, Gijs, Shupe, Matthew, D, Henning, Silvia, Bucci, Silvia, Dütsch, Marina, Stohl, Andreas, Petäjä, Tuukka, Daellenbach, Kaspar, R, Jokinen, Tuija, Schmale, Julia
• Other Authors: Extreme Environments Research Laboratory (EERL), Ecole Polytechnique Fédérale de Lausanne (EPFL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE]Environmental Sciences; [SDE.ES]Environmental Sciences/Environment and Society; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Arctic; Arctic Ocean; Sea ice
• Online Access: https://hal.science/hal-04383091; https://hal.science/hal-04383091/document; https://hal.science/hal-04383091/file/Dada%20et%20al.%20-%202022%20-%20A%20central%20arctic%20extreme%20aerosol%20event%20triggered%20b.pdf; https://doi.org/10.1038/s41467-022-32872-2

International audience Frequency and intensity of warm and moist air-mass intrusions into the Arctic have increased over the past decades and have been related to sea ice melt. During our year-long expedition in the remote central Arctic Ocean, a recordbreaking increase in temperature, moisture and downwelling-longwave radiation was observed in mid-April 2020, during 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. Here we show how the intrusion transformed the Arctic from a remote low-particle environment to an area comparable to a central-European urban setting. Additionally, the intrusion resulted in an explosive increase in cloud condensation nuclei, which can have direct effects on Arctic clouds' radiation, their precipitation patterns, and their lifetime. Thus, unless prompt actions to significantly reduce emissions in the source regions are taken, such intrusion events are expected to continue to affect the Arctic climate. 1234567890():,; 1234567890():,;