Highly Active Ice-Nucleating Particles at the Summer North Pole
Journal article, 2022
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 higher in the boundary layer where clouds form. Back trajectory analysis suggests strong sources of INPs near the Russian coast, possibly associated with wind-driven sea spray production, whereas the pack ice, open leads, and the marginal ice zone were not sources of highly active INPs. These findings suggest that primary ice production, and therefore Arctic climate, is sensitive to transport from locations such as the Russian coast that are already experiencing marked climate change.
Arctic
ice
ice-nucleating particles
mixed-phase clouds
Author
Grace C.E. Porter
University of Leeds
Michael P. Adams
University of Leeds
Ian M. Brooks
University of Leeds
Luisa Ickes
Chalmers, Space, Earth and Environment, Geoscience and Remote Sensing
Linn Karlsson
Stockholm University
Caroline Leck
Stockholm University
Matthew E. Salter
Stockholm University
Julia Schmale
Swiss Federal Institute of Technology in Lausanne (EPFL)
Karolina Siegel
Stockholm University
Sebastien N.F. Sikora
University of Leeds
Mark D. Tarn
University of Leeds
Jutta Vüllers
University of Leeds
Karlsruhe Institute of Technology (KIT)
Heini Wernli
Swiss Federal Institute of Technology in Zürich (ETH)
Paul Zieger
Stockholm University
Julika Zinke
Stockholm University
Benjamin J. Murray
University of Leeds
Journal of Geophysical Research: Atmospheres
2169897X (ISSN) 21698996 (eISSN)
Vol. 127 6 e2021JD036059ModElling the Regional and Global Earth system (MERGE)
Lund University (9945095), 2010-01-01 -- .
Subject Categories
Meteorology and Atmospheric Sciences
Geology
Geosciences, Multidisciplinary
DOI
10.1029/2021JD036059