Inorganic nutrient measurements in the Benguela Upwelling System during METEOR cruise M157

doi:doi:10.1594/PANGAEA.956014

Inorganic nutrient measurements in the Benguela Upwelling System during METEOR cruise M157

Upwelling systems are significant sources of atmospheric nitrous oxide (N₂O). The Benguela Upwelling System is one of the most productive regions worldwide and a temporally variable source of N₂O. Strong O₂ depletions above the shelf are favoring periodically OMZ formations. We aimed to assess underlying N₂O production and consumption processes on different temporal and spatial scales during austral winter in the Benguela Upwelling System, when O₂-deficiency in the water column is relatively low. The fieldwork took place during the cruise M157 (August 4ᵗʰ – September 16ᵗʰ 2019) onboard the R/V METEOR. This expedition included four close-coastal regions around Walvis Bay at 23°S, which presented the lowest O₂ concentrations near the seafloor and thus may provide hotspots of N₂O production. Seawater was collected in 10 L free-flow bottles by using a rosette system equipped with conductivity-temperature-depth (CTD) sensors (SBE 911plus, Seabird-electronics, USA). Concentrations of inorganic nutrients (PO₄³⁻, NH₄⁺, NO₃⁻, NO₂⁻, and SiO₂) were measured colorimetrically according to Grasshoff et al. (1999) by means of a continuous segmented flow analyzer (SEAL Analytical, QuAAtro39). To determine the water mass fractions along the sampling transects, vertical profiles were collected using a free-falling microstructure profiler (MSS90L, Sea & Sun Technology). Temperature, dissolved oxygen, and salinity were measured with a CTD system consisting of a SeaBird 911+ probe, mounted on a sampling rosette.

BibTex:

@dataset{Dangl_Gabriela_and_Frey_Claudia_and_Hassenrück_Christiane_and_Sabbaghzadeh_Bita_and_Wäge-Recchioni_Janine_and_Lehmann_Moritz_F_and_Ley_Martin_and_Rehder_Gregor_and_Jürgens_Klaus_2023,
    abstract = {Upwelling systems are significant sources of atmospheric nitrous oxide (N₂O). The Benguela Upwelling System is one of the most productive regions worldwide and a temporally variable source of N₂O. Strong O₂ depletions above the shelf are favoring periodically OMZ formations. We aimed to assess underlying N₂O production and consumption processes on different temporal and spatial scales during austral winter in the Benguela Upwelling System, when O₂-deficiency in the water column is relatively low. 
The fieldwork took place during the cruise M157 (August 4ᵗʰ – September 16ᵗʰ 2019) onboard the R/V METEOR. This expedition included four close-coastal regions around Walvis Bay at 23°S, which presented the lowest O₂ concentrations near the seafloor and thus may provide hotspots of N₂O production. Seawater was collected in 10 L free-flow bottles by using a rosette system equipped with conductivity-temperature-depth (CTD) sensors (SBE 911plus, Seabird-electronics, USA).
Concentrations of inorganic nutrients (PO₄³⁻, NH₄⁺, NO₃⁻, NO₂⁻, and SiO₂) were measured colorimetrically according to Grasshoff et al. (1999) by means of a continuous segmented flow analyzer (SEAL Analytical, QuAAtro39). To determine the water mass fractions along the sampling transects, vertical profiles were collected using a free-falling microstructure profiler (MSS90L, Sea & Sun Technology). Temperature, dissolved oxygen, and salinity were measured with a CTD system consisting of a SeaBird 911+ probe, mounted on a sampling rosette.},
    author = {Dangl, Gabriela and Frey, Claudia and Hassenrück, Christiane and Sabbaghzadeh, Bita and Wäge-Recchioni, Janine and Lehmann, Moritz F and Ley, Martin and Rehder, Gregor and Jürgens, Klaus},
    doi = {10.1594/PANGAEA.956014},
    institution = {PANGAEA (Chemistry)},
    keyword = {'Benguela Upwelling System', 'Field observation', 'Namibia', 'nutrients', 'oxygen minimum zone', 'water mass fraction'},
    title = {Inorganic nutrient measurements in the Benguela Upwelling System during METEOR cruise M157},
    url = {https://service.tib.eu/ldmservice/vdataset/png-doi-10-1594-pangaea-956014},
    year = {2023}
}