Physical and biogeochemical impacts of migrating zooplankton aggregations
Abstract/Contents
- Abstract
- Biologically generated turbulence has been proposed as an important contributor to nutrient transport and ocean mixing. However, for swimming animals to produce non-negligible transport and mixing, they must produce eddies at scales comparable to the length scales of stratification in the ocean. It has previously been argued that biologically generated turbulence is limited to the scale of the individual animals involved, which would make turbulence created by highly abundant centimeter-scale zooplankton such as krill irrelevant to ocean mixing. Their small size notwithstanding, zooplankton form dense aggregations tens of meters in vertical extent as they undergo diurnal vertical migration over hundreds of meters. In this work, we investigate the potential for this behavior to introduce additional length scales - such as the scale of the aggregation - that are of relevance to animal interactions with the surrounding water column. Utilizing laboratory experiments, we show that the collective vertical migration of centimeter-scale swimmers generates aggregation-scale eddies that mix a stable density stratification, resulting in a significantly enhanced effective turbulent diffusivity. The large-scale fluid transport similarly enhances mixing of other relevant scalars, such as dissolved oxygen, leading to cascading biogeochemical effects upon the water column. Altogether, the results illustrate the potential for marine zooplankton to considerably alter the physical and biogeochemical structure of the water column, with potentially widespread effects owing to their frequent vertical migrations and high abundance in climatically important regions of the ocean.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2019; ©2019 |
| Publication date | 2019; 2019 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Houghton, Isabel Anne |
|---|---|
| Degree supervisor | Dabiri, John O. (John Oluseun) |
| Thesis advisor | Dabiri, John O. (John Oluseun) |
| Thesis advisor | Koseff, Jeffrey Russell |
| Thesis advisor | Monismith, Stephen Gene |
| Thesis advisor | Ouellette, Nicholas (Nicholas Testroet), 1980- |
| Degree committee member | Koseff, Jeffrey Russell |
| Degree committee member | Monismith, Stephen Gene |
| Degree committee member | Ouellette, Nicholas (Nicholas Testroet), 1980- |
| Associated with | Stanford University, Civil & Environmental Engineering Department. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Isabel Anne Houghton. |
|---|---|
| Note | Submitted to the Department of Civil and Environmental Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2019. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2019 by Isabel Anne Houghton
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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