Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. Spatial Variability of Turbulent Mixing From an Underwater Glider in a Large, Deep, Stratified Lake
 
research article

Spatial Variability of Turbulent Mixing From an Underwater Glider in a Large, Deep, Stratified Lake

Steiner, Oscar Sepulveda  
•
Forrest, Alexander L.
•
McInerney, Jasmin B. T.
Show more
June 1, 2023
Journal of Geophysical Research: Oceans

Recent efforts using microstructure turbulence measurements have contributed to our understanding of the overall energy budget in lakes and linkages to vertical fluxes. A paucity of lake-wide turbulence measurements hinders our ability to assess how representative such budgets are at the basin scale. Using an autonomous underwater glider equipped with a microstructure payload, we explored the spatial variability of turbulence in pelagic and near-shore regions of Lake Geneva. Dissipation rates of kinetic energy and thermal variance were estimated by fitting temperature gradient fluctuations spectra to the Batchelor spectrum. In deep waters, turbulent dissipation rates in the surface and thermocline were mild (similar to 10(-8) W kg(-1)) and weakened toward the hypolimnion (similar to 10(-11) to 10(-10) W kg(-1)). The seasonal thermocline exhibited inhibited interior mixing, with extremely low values of mixing efficiency (Ri(f) << 0.1). In contrast, in the slope zone, a band of significantly enhanced energy dissipation (similar to 5 x 10(-8) W kg(-1)) extended well above the bottom boundary layer and was associated with strong, efficient mixing (Ri(f) > 0.17). The resulting contribution of the slope region to basin-scale mixing was large, with 90% of the basin-wide mixing-and only 30% energy dissipation-occurring within 4 km of the shoreline. This boundary mixing will modify overturning circulation and the transport pathways of dissolved compounds exchanged with the sediments. The dynamics responsible for the shift in the mixing regime, which appears crucial for the mixing budget of lakes, could not be fully unraveled with the collected observations. Additional model data analyses hint at the role of submesoscale instabilities.

  • Details
  • Metrics
Type
research article
DOI
10.1029/2022JC018913
Web of Science ID

WOS:001006252600001

Author(s)
Steiner, Oscar Sepulveda  
Forrest, Alexander L.
McInerney, Jasmin B. T.
Castro, Bieito Fernandez  
Lavanchy, Sebastien  
Wuest, Alfred  
Bouffard, Damien
Date Issued

2023-06-01

Publisher

AMER GEOPHYSICAL UNION

Published in
Journal of Geophysical Research: Oceans
Volume

128

Issue

6

Article Number

e2022JC018913

Subjects

Oceanography

•

Oceanography

•

turbulence

•

mixing

•

underwater glider

•

microstructure

•

boundary mixing

•

lake geneva (lac leman)

•

kinetic-energy dissipation

•

boundary-layers

•

dynamics

•

temperature

•

diffusivity

•

victoria

•

fluid

•

ocean

•

hydrodynamics

•

hypolimnion

Editorial or Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
APHYS  
Available on Infoscience
July 17, 2023
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/199213
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés