N2O and CH4 underway measurements (atmosphere and ocean) during METEOR cruise M120


Upward transport and/or mixing of trace gas-enriched subsurface waters fosters the exchange of nitrous oxide (N2O) and methane (CH4) with the atmosphere in the Eastern-South Atlantic (ESA). To date, it is, however, unclear whether this source is maintained by local production or advection of trace-gas enriched water masses. So, the meridional and zonal variability of N2O and CH4 in the ESA were investigated to constrain the contributions of the major regional water masses to the overall budget of N2O and CH4. The fieldwork took place during the cruises M99 (July 31st - August 23rd, 2013) and M120 (October 17th - November 18th, 2015) onboard the R/V METEOR, which encompassed close-coastal and open ocean regions off Angola and Namibia. To investigate the regional concentration gradients of N2O and CH4 and corresponding sea-air fluxes, seven hydrographic sections (six zonal transects and one alongshore transect) were conducted between ~10°S and 26°S. Concentrations of dissolved N2O and CH4 in surface waters were continuously measured by using the Mobile Equilibrator Sensor System. To evaluate, the oceanic-atmospheric trace gas exchange, the atmospheric N2O and CH4 in ambient air were measured at several sporadic locations, with an inlet installed at 35 m height. The data were quality controlled by comparing with the data generated by NOAA in the nearest atmospheric sampling station (23.58° S, 15.03°E, Station NMB (Gobabeb, Namibia)). Also, to better understand the underlying patterns of the trace gas in the ESA, the vertical profiles were investigated by measuring discrete samples of N2O using the dynamic headspace method on M99. N2O and CH4 concentrations were also measured using a purge and trap system during M120 expedition.

DOI https://doi.org/10.1594/PANGAEA.936687
Related Identifier https://doi.org/10.1594/PANGAEA.936689
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.936687
Creator Sabbaghzadeh, Bita ORCID logo
Publisher PANGAEA
Publication Year 2021
Funding Reference Seventh Framework Programme https://doi.org/10.13039/100011102 Crossref Funder ID 603521 https://cordis.europa.eu/project/id/603521 Enhancing Prediction of Tropical Atlantic Climate and its Impact
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Resource Type Dataset
Format text/tab-separated-values
Size 302456 data points
Discipline Earth System Research
Spatial Coverage (10.583W, -23.023S, 14.367E, -6.208N)
Temporal Coverage Begin 2015-10-29T00:00:00Z
Temporal Coverage End 2015-11-17T10:31:00Z