Highly Active Ice-Nucleating Particles at the Summer North Pole ...

• Main Authors: Porter, Grace C.E., Adams, Michael P., Brooks, Ian M., Ickes, Luisa, Karlsson, Linn, Leck, Caroline, Salter, Matthew E., Schmale, Julia, Siegel, Karolina, Sikora, Sebastien N. F., Tarn, Mark D., Vüllers, Jutta, Wernli, Heini, Zieger, Paul, Zinke, Julika, Murray, Benjamin J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2022
• Subjects: North Pole; Southern Ocean
• Online Access: https://dx.doi.org/10.3929/ethz-b-000541830; http://hdl.handle.net/20.500.11850/541830

The amount of ice versus supercooled water in clouds is important for their radiative properties and role in climate feedbacks. Hence, knowledge of the concentration of ice-nucleating particles (INPs) is needed. Generally, the concentrations of INPs are found to be very low in remote marine locations allowing cloud water to persist in a supercooled state. We had expected the concentrations of INPs at the North Pole to be very low given the distance from open ocean and terrestrial sources coupled with effective wet scavenging processes. Here we show that during summer 2018 (August and September) high concentrations of biological INPs (active at >−20°C) were sporadically present at the North Pole. In fact, INP concentrations were sometimes as high as those recorded at mid-latitude locations strongly impacted by highly active biological INPs, in strong contrast to the Southern Ocean. Furthermore, using a balloon borne sampler we demonstrated that INP concentrations were often different at the surface versus ... : Journal of Geophysical Research: Atmospheres, 127 (6) ...