 |
| Titel |
Particle-reactive radionuclides (234Th, 210Pb, 210) as tracers for the estimation of export production in the South China Sea |
| VerfasserIn |
C.-L. Wei, S.-Y. Lin, D. D.-D. Sheu, W.-C. Chou, M.-C. Yi, P. H. Santschi, L.-S. Wen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 12 ; Nr. 8, no. 12 (2011-12-21), S.3793-3808 |
| Datensatznummer |
250006257
|
| Publikation (Nr.) |
 copernicus.org/bg-8-3793-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| The time-series station, SEATS (18° N, 116° E) in the South China Sea
was visited six times during October 2006–December 2008 to carry out
seawater sampling and floating trap deployments for the determination of
distributions and fluxes of POC, PIC, PN, 234Th, 210Pb, and
210Po in the upper 200 m of the water column. Radionuclide deficiencies
resulted in removal fluxes from the euphotic layer of 1.1×103–1.8×103 dpm m−2d−1 and 7.1–40.2 dpm m−2d−1
for 234Th and 210Po, respectively. Due to atmospheric
input, an excess of 210Pb relative to 226Ra is commonly observed
in the upper water column. Sinking fluxes of total mass, POC, PIC, PN,
234Th, 210Pb, and 210Po measured at the euphotic depth were
low in summer-fall and high in winter-spring, reflecting the seasonal
variability of biological pumping. Excluding the suspiciously low primary
productivity data point in July 2007, a relatively high e-ratio of 0.28–0.69
was estimated by the ratio of the POC flux at the euphotic depth and the
integrated primary productivity. The ratios of 234Th, 210Pb, and
210Po to organic carbon, inorganic carbon, and nitrogen in the sinking
particles were combined with the disequilibria of 234Th–238U,
210Pb–226Ra, and 210Po–210Pb to estimate export fluxes
of POC, PIC, and PN from the euphotic layer. Compared with measured fluxes
by the sediment trap and estimated fluxes by other approaches, it is
concluded that the export production in the South China Sea, ranging from
1.8 to 21.3 mmol-C m−2d−1, can be reasonably estimated using
234Th, 210Pb, and 210Po as carbon proxies. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|