Schafstall, Jens; Dengler, Marcus; Brandt, Peter; Bange, Hermann Werner (2010): Tidal-induced mixing and diapycnal nutrient fluxes in the Mauritanian upwelling region [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.860358, Supplement to: Schafstall, J et al. (2010): Tidal-induced mixing and diapycnal nutrient fluxes in the Mauritanian upwelling region. Journal of Geophysical Research, 115(C10), https://doi.org/10.1029/2009JC005940
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Abstract:
The Mauritanian coastal area is one of the most biologically productive upwelling regions in the world ocean. Shipboard observations carried out during maximum upwelling season and short-term moored observations are used to investigate diapycnal mixing processes and to quantify diapycnal fluxes of nutrients. The observations indicate strong tide-topography interactions that are favored by near-critical angles occurring on large parts of the continental slope. Moored velocity observations reveal the existence of highly nonlinear internal waves and bores and levels of internal wave spectra are strongly elevated near the buoyancy frequency. Dissipation rates of turbulent kinetic energy at the slope and shelf determined from microstructure measurements in the upper 200 m averages to ? = 5 × 10-8 W kg-1. Particularly elevated dissipation rates were found at the continental slope close to the shelf break, being enhanced by a factor of 100 to 1000 compared to dissipation rates farther offshore. Vertically integrated dissipation rates per unit volume are strongest at the upper continental slope reaching values of up to 30 mW m-2. A comparison of fine-scale parameterizations of turbulent dissipation rates for shelf regions and the open ocean to the measured dissipation rates indicates deficiencies in reproducing the observations. Diapycnal nitrate fluxes above the continental slope at the base of the mixed layer yielding a mean value of 12 × 10-2 µmol m-2 s-1 are amongst the largest published to date. However, they seem to only represent a minor contribution (10% to 25%) to the net community production in the upwelling region.
Related to:
Dengler, Marcus; Schafstall, Jens (2008): Physical oceanography of 126 CTD casts during POSEIDON cruise POS347 in the Atlantic Ocean. PANGAEA, https://doi.org/10.1594/PANGAEA.771866
Krahmann, Gerd; Bange, Hermann Werner (2015): Physical oceanography during POSEIDON cruise POS348. IFM-GEOMAR Leibniz-Institute of Marine Sciences, Kiel University, PANGAEA, https://doi.org/10.1594/PANGAEA.848597
Stramma, Lothar (2012): Physical oceanography during METEOR cruise M68/3. IFM-GEOMAR Leibniz-Institute of Marine Sciences, Kiel University, PANGAEA, https://doi.org/10.1594/PANGAEA.787808
Project(s):
Coverage:
Median Latitude: 18.163867 * Median Longitude: -18.707992 * South-bound Latitude: 17.250000 * West-bound Longitude: -24.750000 * North-bound Latitude: 20.000000 * East-bound Longitude: -16.247800
Date/Time Start: 2007-01-21T10:01:00 * Date/Time End: 2007-02-22T18:43:59
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
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2 datasets
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Datasets listed in this publication series
- Dengler, M (2015): Microstructure measurements during POSEIDON cruise POS347. https://doi.org/10.1594/PANGAEA.854068
- Dengler, M (2015): Microstructure measurements during POSEIDON cruise POS348. https://doi.org/10.1594/PANGAEA.853808