Articles | Volume 19, issue 2
Research article
 | Highlight paper
21 Feb 2023
Research article | Highlight paper |  | 21 Feb 2023

Non-spherical microparticle shape in Antarctica during the last glacial period affects dust volume-related metrics

Aaron Chesler, Dominic Winski, Karl Kreutz, Bess Koffman, Erich Osterberg, David Ferris, Zayta Thundercloud, Joseph Mohan, Jihong Cole-Dai, Mark Wells, Michael Handley, Aaron Putnam, Katherine Anderson, and Natalie Harmon

Data sets

South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements Karl Kreutz

Model code and software

Atmospheric Dynamics during the Abrupt Climate Change Events of the Last Glacial Period K. L. Anderson

Knowledge of microparticle geometry is essential for accurate calculation of ice core volume-related dust metrics (mass, flux, and particle size distributions) and subsequent paleoclimate interpretations, yet particle shape data remain sparse in most of ice core records. The approach and results of this work are of interest for the broad geoscience community, since it potentially enables a better characterization of all data obtained from the dust in ice cores. This study of samples from South Pole ice core (SPC14) indicates that coarser particles (>5.0 μm diameter) show greater variation in measured aspect ratios than finer particles (<5.0 μm). While fine particle volumes can be accurately estimated using the spherical assumption, applying the same assumption to coarse particles has a large effect on inferred particle volumes.
Short summary
Ice core microparticle data typically use geometry assumptions to calculate particle mass and flux. We use dynamic particle imaging, a novel technique for ice core dust analyses, combined with traditional laser particle counting and Coulter counter techniques to assess particle shape in the South Pole Ice Core (SPC14) spanning 50–16 ka. Our results suggest that particles are dominantly ellipsoidal in shape and that spherical assumptions overestimate particle mass and flux.