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Titel |
Air–water fluxes and sources of carbon dioxide in the Delaware Estuary: spatial and seasonal variability |
VerfasserIn |
A. Joesoef, W.-J. Huang, Y. Gao, W.-J. Cai |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 12, no. 20 ; Nr. 12, no. 20 (2015-10-26), S.6085-6101 |
Datensatznummer |
250118139
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Publikation (Nr.) |
copernicus.org/bg-12-6085-2015.pdf |
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Zusammenfassung |
Distributions of surface water partial pressure of carbon dioxide
(pCO2) were measured on nine cruises in the Delaware Estuary (USA). The
Delaware River was highly supersaturated in pCO2 with respect to the
atmosphere during all seasons, while the Delaware Bay was undersaturated in
pCO2 during spring and late summer and moderately supersaturated during
mid-summer, fall, and winter. While the smaller upper tidal river was a
strong CO2 source (27.1 ± 6.4 mol-C m−2 yr−1), the much
larger bay was a weak source (1.2 ± 1.4 mol-C m−2 yr−1), the
latter of which had a much greater area than the former. In turn, the
Delaware Estuary acted as a relatively weak CO2 source (2.4 ± 4.8 mol-C m−2 yr−1), which is in great contrast to many other
estuarine systems. Seasonally, pCO2 changes were greatest at low
salinities (0 ≤ S < 5), with pCO2 values in the summer
nearly 3-fold greater than those observed in the spring and fall.
Undersaturated pCO2 was observed over the widest salinity range (7.5 ≤ S < 30) during spring. Near to supersaturated pCO2 was
generally observed in mid- to high-salinity waters (20 ≤ S < 30) except during spring and late summer. Strong seasonal trends in internal
estuarine production and consumption of CO2 were observed throughout
both the upper tidal river and lower bay. Positive correlations
between river-borne and air–water CO2 fluxes in the upper estuary
emphasize the significance of river-borne CO2 degassing to overall
CO2 fluxes. While river-borne CO2 degassing heavily influenced
CO2 dynamics in the upper tidal river, these forces were largely
compensated for by internal biological processes within the extensive bay system
of the lower estuary. |
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