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| Titel |
Seasonal net and gross biological oxygen production in a temperate shelf sea
from oxygen-argon-ratio and oxygen triple isotopes. |
| VerfasserIn |
Isabel Seguro, Alina Marca, Jan Kaiser |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250144608
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| Publikation (Nr.) |
 EGU/EGU2017-8454.pdf |
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| Zusammenfassung |
| Temperate shelf seas are major carbon sink areas. Quantifying accurately primary production
is therefore essential to understand the shelf sea carbon pump and its role in the uptake of
anthropogenic CO2 emissions.
Here we use high-resolution dissolved oxygen-to-argon (O2/Ar) ratios and oxygen triple
isotopes (16O, 17O and 18O) to derive estimates of net and gross biological oxygen
production in the Celtic Sea during the most productive seasons (spring, summer and autumn)
in 2014-2015. O2/Ar ratios were measured continuously using a shipboard membrane inlet
mass spectrometer (MIMS). Additional discrete water samples obtained from CTD
hydrocasts were used to measure O2/Ar depth profiles and the δ(17O) and δ(18O) values of
dissolved O2.
Calculations of net (N(O2/Ar)) and gross (G(17O)) oxygen fluxes showed higher
values during the spring bloom and lowest during the autumn bloom. Continuous
N(O2/Ar) underway measurement was on average (58±38) mmol m−2 d−1 and discrete
G(17O) measurements was average (170±161) mmol m−2 d−1 during the spring
bloom. Results from the summer cruise showed a peak in production just below
the mixed layer. These peaks are not detectable by high coverage ocean colour
satellite systems, typically used to calculate total annual production. Our results
show primary production values at unprecedentedly high resolution in the shelf sea. |
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