Black carbon scavenging by low-level Arctic clouds

• Published in: Nature Communications
• Main Authors: Paul Zieger, Dominic Heslin-Rees, Linn Karlsson, Makoto Koike, Robin Modini, Radovan Krejci
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2023
• Subjects: Science; Q; Arctic; Svalbard; black carbon
• Online Access: https://doi.org/10.1038/s41467-023-41221-w; https://doaj.org/article/f393e863955f42b6ad13076ee27ab072

Abstract Black carbon (BC) from anthropogenic and natural sources has a pronounced climatic effect on the polar environment. The interaction of BC with low-level Arctic clouds, important for understanding BC deposition from the atmosphere, is studied using the first long-term observational data set of equivalent black carbon (eBC) inside and outside of clouds observed at Zeppelin Observatory, Svalbard. We show that the measured cloud residual eBC concentrations have a clear seasonal cycle with a maximum in early spring, due to the Arctic haze phenomenon, followed by cleaner summer months with very low concentrations. The scavenged fraction of eBC was positively correlated with the cloud water content and showed lower scavenged fractions at low temperatures, which may be due to mixed-phase cloud processes. A trajectory analysis revealed potential sources of eBC and the need to ensure that aerosol-cloud measurements are collocated, given the differences in air mass origin of cloudy and non-cloudy periods.