A long-term study of cloud residuals from low-level Arctic clouds
Open Access
- 14 June 2021
- journal article
- research article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 21 (11), 8933-8959
- https://doi.org/10.5194/acp-21-8933-2021
Abstract
To constrain uncertainties in radiative forcings associated with aerosol-cloud interactions, improved understanding of Arctic cloud formation is required, yet long-term measurements of the relevant cloud and aerosol properties remain sparse. We present the first long-term study of cloud residuals, i.e. particles that were involved in cloud formation and cloud processes, in Arctic low-level clouds measured at Zeppelin Observatory, Svalbard. To continuously sample cloud droplets and ice crystals and separate them from non-activated aerosol, a ground-based counter-flow virtual impactor inlet system (GCVI) was used. A detailed evaluation of the GCVI measurements, using concurrent cloud particle size distributions, meteorological parameters, and aerosol measurements, is presented for both warm and cold clouds, and the potential contribution of sampling artefacts is discussed in detail. We find an excellent agreement of the GCVI sampling efficiency of liquid clouds using two independent approaches. The 2-year data set of cloud residual size distributions and number concentrations reveals that the cloud residuals follow the typical seasonal cycle of Arctic aerosol, with a maximum concentration in spring and summer and a minimum concentration in the late autumn and winter months. We observed average activation diameters in the range of 58-78 nm for updraught velocities below 1 m s(-1). A cluster analysis also revealed cloud residual size distributions that were dominated by Aitken mode particles down to around 20-30 nm. During the winter months, some of these small particles may be the result of ice, snow, or ice crystal shattering artefacts in the GCVI inlet; however, cloud residuals down to 20 nm in size were also observed during conditions when artefacts are less likely.Funding Information
- Ministry of Education, Culture, Sports, Science and Technology (MEXT ArCS Project)
- Deutsche Forschungsgemeinschaft (268020496)
- Svenska Forskningsrådet Formas (2016-01427)
- Naturvårdsverket (Miljöövervakning)
- Knut och Alice Wallenbergs Stiftelse (2016.0024)
This publication has 64 references indexed in Scilit:
- The importance of Aitken mode aerosol particles for cloud sustenance in the summertime high Arctic – a simulation study supported by observational dataAtmospheric Chemistry and Physics, 2021
- Differing Mechanisms of New Particle Formation at Two Arctic SitesGeophysical Research Letters, 2021
- Impact of surface and near-surface processes on ice crystal concentrations measured at mountain-top research stationsAtmospheric Chemistry and Physics, 2018
- Contribution of Atmospheric Advection to the Amplified Winter Warming in the Arctic North Atlantic RegionAdvances in Meteorology, 2017
- Arctic sea ice melt leads to atmospheric new particle formationScientific Reports, 2017
- Cloud Ice Properties: In Situ Measurement ChallengesMeteorological Monographs, 2017
- Clouds and AerosolsPublished by Cambridge University Press (CUP) ,2014
- Ubiquitous low‐level liquid‐containing Arctic clouds: New observations and climate model constraints from CALIPSO‐GOCCPGeophysical Research Letters, 2012
- Predicting global atmospheric ice nuclei distributions and their impacts on climateProceedings of the National Academy of Sciences of the United States of America, 2010
- APPLICATION OF THE T-MATRIX METHOD TO THE MEASUREMENT OF ASPHERICAL (ELLIPSOIDAL) PARTICLES WITH FORWARD SCATTERING OPTICAL PARTICLE COUNTERSJournal of Aerosol Science, 2000