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Title: Hidden comet tails of marine snow impede ocean-based carbon sequestration
Gravity-driven sinking of “marine snow” sequesters carbon in the ocean, constituting a key biological pump that regulates Earth’s climate. A mechanistic understanding of this phenomenon is obscured by the biological richness of these aggregates and a lack of direct observation of their sedimentation physics. Utilizing a scale-free vertical tracking microscopy in a field setting, we present microhydrodynamic measurements of freshly collected marine snow aggregates from sediment traps. Our observations reveal hitherto-unknown comet-like morphology arising from fluid-structure interactions of transparent exopolymer halos around sinking aggregates. These invisible comet tails slow down individual particles, greatly increasing their residence time. Based on these findings, we constructed a reduced-order model for the Stokesian sedimentation of these mucus-embedded two-phase particles, paving the way toward a predictive understanding of marine snow.  more » « less
Award ID(s):
2021032
PAR ID:
10556244
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
AAAS
Date Published:
Journal Name:
Science
Volume:
386
Issue:
6718
ISSN:
0036-8075
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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