Air–Sea Fluxes of Greenhouse Gases and Oxygen in the Northern Benguela Current Region During Upwelling Events.

Morgan, Eric.J., Lavric, Jost V., Arévalo-Martínez, Damian L. , Bange, Hermann W. , Steinhoff, Tobias, Seifert, Thomas and Heimann, Martin (2019) Air–Sea Fluxes of Greenhouse Gases and Oxygen in the Northern Benguela Current Region During Upwelling Events. Open Access Biogeosciences Discussions . DOI https://doi.org/10.5194/bg-2019-103.

[img]
Preview
Text
bg-2019-103.pdf - Published Version
Available under License Creative Commons: Attribution 4.0.

Download (18Mb) | Preview
[img] Archive
bg-2019-103-supplement.zip - Supplemental Material
Available under License Creative Commons: Attribution 4.0.

Download (400Kb)

Supplementary data:

Abstract

Ground-based atmospheric observations of CO2, δ(O2/N2), N2O, and CH4 were used to make top-down estimates of the air–sea fluxes of these species from the Lüderitz and Walvis Bay upwelling cells in the northern Benguela region, during upwelling events. Average flux densities (±1σ) were 0.64 ± 0.4 μmol m−2 sec−1 for CO2, −5.1 ± 1.4 μmol m−2 sec−1 for O2 (as APO), 0.57 ± 0.3 nmol m−2 sec−1 for N2O, and 4.3 ± 5.5 nmol m−2 sec−1 for CH4. A comparison of our top-down flux estimates with shipboard-based measurements showed good agreement between both approaches. During the study, upwelling events were sources of CO2, N2O, and CH4 to the atmosphere. N2O fluxes were fairly low, in accordance with previous work suggesting that the evasion of this gas from the Benguela is smaller than for other Eastern Boundary Upwelling Systems (EBUS). Conversely, CH4 release was quite high for the marine environment, a result that supports studies that indicated a large sedimentary source of CH4 in the Walvis Bay area. These results demonstrate the suitability of atmospheric time series for characterizing the temporal variability of upwelling events and their influence on the overall marine GHG emissions from the northern Benguela region.

Document Type: Article
Funder compliance: 284274
Keywords: Greenhouse gases Oxygen Northern Benguela Coastal Upwelling EBUS
Research affiliation: OceanRep > GEOMAR > FB2 Marine Biogeochemistry > FB2-CH Chemical Oceanography
OceanRep > The Future Ocean - Cluster of Excellence > FO-R07
OceanRep > The Future Ocean - Cluster of Excellence
Refereed: No
Open Access Journal?: Yes
DOI etc.: https://doi.org/10.5194/bg-2019-103
ISSN: 1810-6285
Projects: SOPRAN, InGOS, Future Ocean
Expeditions/Models/Experiments:
Date Deposited: 27 Mar 2019 13:28
Last Modified: 27 Mar 2019 13:28
URI: http://oceanrep.geomar.de/id/eprint/46212

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...