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dc.contributor.authorDoostmohammadi, Amin
dc.contributor.authorStocker, Roman
dc.contributor.authorArdekani, Arezoo M.
dc.date.accessioned2012-11-07T18:56:29Z
dc.date.available2012-11-07T18:56:29Z
dc.date.issued2012-02
dc.date.submitted2011-10
dc.identifier.issn0027-8424
dc.identifier.issn1091-6490
dc.identifier.urihttp://hdl.handle.net/1721.1/74588
dc.description.abstractMicroorganisms play pivotal functions in the trophic dynamics and biogeochemistry of aquatic ecosystems. Their concentrations and activities often peak at localized hotspots, an important example of which are pycnoclines, where water density increases sharply with depth due to gradients in temperature or salinity. At pycnoclines organisms are exposed to different environmental conditions compared to the bulk water column, including reduced turbulence, slow mass transfer, and high particle and predator concentrations. Here we show that, at an even more fundamental level, the density stratification itself can affect microbial ecology at pycnoclines, by quenching the flow signature, increasing the energetic expenditure, and stifling the nutrient uptake of motile organisms. We demonstrate this through numerical simulations of an archetypal low-Reynolds-number swimmer, the “squirmer.” We identify the Richardson number—the ratio of buoyancy forces to viscous forces—as the fundamental parameter that quantifies the effects of stratification. These results demonstrate an unexpected effect of buoyancy on low-Reynolds-number swimming, potentially affecting a broad range of abundant organisms living at pycnoclines in oceans and lakes.en_US
dc.description.sponsorshipNational Science Foundation (U.S.) (Grant CBET-1066545)en_US
dc.language.isoen_US
dc.publisherNational Academy of Sciencesen_US
dc.relation.isversionofhttp://dx.doi.org/10.1073/pnas.1116210109en_US
dc.rightsArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.en_US
dc.sourcePNASen_US
dc.titleLow-Reynolds-number swimming at pycnoclinesen_US
dc.typeArticleen_US
dc.identifier.citationDoostmohammadi, A., R. Stocker, and A. M. Ardekani. “Low-Reynolds-number Swimming at Pycnoclines.” Proceedings of the National Academy of Sciences 109.10 (2012): 3856–3861. ©2012 by the National Academy of Sciencesen_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Civil and Environmental Engineeringen_US
dc.contributor.mitauthorStocker, Roman
dc.relation.journalProceedings of the National Academy of Sciencesen_US
dc.eprint.versionFinal published versionen_US
dc.type.urihttp://purl.org/eprint/type/JournalArticleen_US
eprint.statushttp://purl.org/eprint/status/PeerRevieweden_US
dspace.orderedauthorsDoostmohammadi, A.; Stocker, R.; Ardekani, A. M.en
dc.identifier.orcidhttps://orcid.org/0000-0002-3199-0508
mit.licensePUBLISHER_POLICYen_US


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