Nitrous oxide measurements in the Benguela Upwelling System during METEOR cruise M157

DOI

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).Seawater samples were collected from 10 L free-flow bottles bubble-free, filled into 200 mL serum bottles and immediately fixed with saturated mercury chloride (HgCl₂). Concentrations of dissolved N₂O were measured by a purge and trap system using a dynamic headspace (Sabbaghzadeh et al., 2021). The N₂O gas saturation (N₂Oₛₐₜ in %) was calculated from the concentration ratio between the seawater sample and seawater equilibrated with the atmosphere. ∆N₂O (N₂O saturation disequilibrium in nmol L⁻¹) was calculated as the difference between the measured N₂O concentration and the atmospheric equilibrium N₂O concentration using Bunsen solubility coefficient (Weiss and Price, 1980). AOU (apparent oxygen utilization in µmol L⁻¹) expresses the O₂ consumption by microbial respiration and was calculated as the difference between the equilibrated O₂ and observed O₂ concentration with the same physico-chemical properties (Weiss and Price, 1980).

Identifier
DOI https://doi.org/10.1594/PANGAEA.955991
Related Identifier References https://www.ebi.ac.uk/ena/browser/view/PRJEB60503
Related Identifier References https://doi.org/10.1594/PANGAEA.956014
Related Identifier References https://doi.org/10.1594/PANGAEA.956016
Related Identifier References https://www.ebi.ac.uk/ena/browser/view/PRJEB63098
Related Identifier References https://doi.org/10.1594/PANGAEA.946811
Related Identifier References https://www.ldf.uni-hamburg.de/meteor/wochenberichte/wochenberichte-meteor/m156-m159/m157-scr.pdf
Related Identifier References https://doi.org/10.1029/2020JC016878
Related Identifier References https://doi.org/10.1016/0304-4203(80)90024-9
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.955991
Provenance
Creator Dangl, Gabriela ORCID logo; Frey, Claudia ORCID logo; Hassenrück, Christiane ORCID logo; Sabbaghzadeh, Bita ORCID logo; Wäge-Recchioni, Janine; Lehmann, Moritz F ORCID logo; Ley, Martin; Rehder, Gregor ORCID logo; Jürgens, Klaus ORCID logo
Publisher PANGAEA
Publication Year 2023
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Resource Type Dataset
Format text/tab-separated-values
Size 332 data points
Discipline Earth System Research
Spatial Coverage (14.047W, -23.000S, 14.367E, -23.000N)
Temporal Coverage Begin 2019-08-21T20:00:00Z
Temporal Coverage End 2019-08-24T04:52:00Z