Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 2.539 IF 2.539
  • IF 5-year value: 3.129 IF 5-year
    3.129
  • CiteScore value: 2.78 CiteScore
    2.78
  • SNIP value: 1.217 SNIP 1.217
  • IPP value: 2.62 IPP 2.62
  • SJR value: 1.370 SJR 1.370
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 48 Scimago H
    index 48
  • h5-index value: 32 h5-index 32
Discussion papers
https://doi.org/10.5194/os-2019-108
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/os-2019-108
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 24 Oct 2019

Submitted as: research article | 24 Oct 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Ocean Science (OS).

High-resolution physical-biogeochemical structure of a filament and an eddy of upwelled water off Northwest Africa

Wilken-Jon von Appen1, Volker H. Strass1, Astrid Bracher1, Hongyan Xi1, Cora Hörstmann1, Morten H. Iversen1, and Anya M. Waite2 Wilken-Jon von Appen et al.
  • 1Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven,Germany
  • 2Department of Oceanography, and the Ocean Frontier Institute, Dalhousie University, Halifax, Nova Scotia, Canada

Abstract. Nutrient rich water upwells offshore of Northwest Africa and is subsequently advected westwards. There it forms eddies and filaments with a rich spatial structure of physical and biological/biogeochemical properties. Here we present a high resolution (2.5 km) section through upwelling filaments and an eddy obtained in May 2018 with a Triaxus towed vehicle equipped with various oceanographic sensors. Physical processes at the mesoscale and submesoscale such as symmetric instability, trapping of fluid in eddies, and subduction of low potential vorticity (which we use as a water mass tracer) water can explain the observed distribution of biological production and export. We found a nitrate excess (higher nitrate concentrations than would be expected from oxygen values if only influenced by production and remineralization processes) core of an anti-cyclonic mode water eddy. We also found a high nitrate concentration region of ~5 km width in the mixed layer where symmetric instability appears to have injected nutrients from below into the euphotic zone. A similar region a little further south had high chlorophyll-a concentrations suggesting that nutrients had been injected there a few days earlier. Considering that such interactions of physics and biology are ubiquitous in the world's upwelling regions, we assume that they have strong influences on the productivity of such systems and their role in CO2 uptake. The intricate interplay of different parameters at kilometer scale needs to be taken into account when interpreting single profile and/or bottle data in dynamically active regions of the ocean.

Wilken-Jon von Appen et al.
Interactive discussion
Status: open (until 20 Dec 2019)
Status: open (until 20 Dec 2019)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Wilken-Jon von Appen et al.
Data sets

Physical oceanography during POLARSTERN cruise PS113 V. H. Strass https://doi.org/10.1594/PANGAEA.898716

Continuous thermosalinograph oceanography along POLARSTERN cruise track PS113 (ANT-XXXIII/4) V. H. Strass and G. Rohardt https://doi.org/10.1594/PANGAEA.895581

Raw data from Triaxus topAWI tows during POLARSTERN cruise PS113 W.-J. von Appen, V. H. Strass, H. Becker, A. Bracher, and S. Spahic https://doi.org/10.1594/PANGAEA.904420

Raw data of continuous VM-ADCP (vessel-mounted Acoustic Doppler Current Profiler) profile during POLARSTERN cruise PS113 H. Witte https://doi.org/10.1594/PANGAEA.897092

Wilken-Jon von Appen et al.
Viewed  
Total article views: 170 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
137 28 5 170 9 3 5
  • HTML: 137
  • PDF: 28
  • XML: 5
  • Total: 170
  • Supplement: 9
  • BibTeX: 3
  • EndNote: 5
Views and downloads (calculated since 24 Oct 2019)
Cumulative views and downloads (calculated since 24 Oct 2019)
Viewed (geographical distribution)  
Total article views: 128 (including HTML, PDF, and XML) Thereof 127 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited  
Saved  
No saved metrics found.
Discussed  
No discussed metrics found.
Latest update: 20 Nov 2019
Publications Copernicus
Download
Short summary
Nutrient rich water is moved to the surface near continental margins. Then it forms rich, but difficult to observe, spatial structures of physical and biological/biogeochemical properties. Here we present a high resolution (2.5 km) section through such features obtained in May 2018 with a vehicle towed behind a ship. Considering that such interactions of physics and biology are common in the ocean, they likely strongly influence the productivity of such systems and their role in CO2 uptake.
Nutrient rich water is moved to the surface near continental margins. Then it forms rich, but...
Citation