A balanced nitrogen budget of the surface layer of the southern Ross Sea, Antarctica

Smith, Walker O; Asper, Vernon

doi:10.1029/1999gl011034

Cited by 12 publications

(2 citation statements)

References 22 publications

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“…Indeed, Nelson et al (1996), based on data from the Ross Sea, warn that the export production as measured below the surface layer hinges on the depth at which the export has been determined. Measuring export at 200 m in the Ross Sea, though, leads to a consistent picture of the nitrogen budget (Smith and Asper, 2000). Occasionally, bacteria may consume up to 100% of the primary production (Gleitz et al, 1994), causing a great reduction of sinking detritus and a large flux of dissolved material.…”

Section: Discussionmentioning

confidence: 99%

Annual export production in the interior Weddell Gyre estimated from a chemical mass balance of nutrients

Hoppema

Baar

Bellerby

et al. 2002

Deep Sea Research Part II: Topical Studies in Oceanography

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Nitrate, phosphate and silicate data are presented from 1992 austral winter and 1998 austral autumn cruises with ''FS Polarstern'' in the Weddell Gyre. Because in the Weddell Gyre, away from the boundary current, the surface layer is eventually formed from upwelled deep water, the difference in nutrient concentrations between these layers can be used to compute net nutrient consumptions (identical with the export production). This method renders a value for the export production that is based on observed annual changes. The results are consistent for two years and two regions within the central gyre. The calculated net nitrate and phosphate consumptions were scaled to net carbon consumptions using canonical Redfield ratios, yielding 16-17 mmol C kg À1 yr À1 . This equals 2174 g C m À2 yr À1 as a robust estimate for the marginal ice zone. The net annual silicate consumption in the surface layer, which equals the export of biogenic silica, amounts to 15-18 mmol kg À1 yr À1. There is a tendency for higher values in the eastern Weddell Gyre. The estimated silicate consumption of about 1.8 mol Si m À2 yr À1 is relatively high compared to earlier estimations of biogenic silica export. The silicate to carbon consumption ratio of about 1 is very high, and documents the dominance of diatoms in the export of organic material. r 2002 Elsevier Science Ltd. All rights reserved.Re´sumeŚ ont pr! esent! ees les distributions verticales de nitrate, de phosphate et de silicate en Mer de Weddell, pour les p! eriodes de l'hiver austral 1992 et de l'automne austral 1998. Les eaux de surface du tourbillon " a grande ! echelle de la Mer de Weddell (temps de r! esidence ! egal " a 2.9 ans) sont form! ees par l'upwelling des eaux profondes. La diff! erence de concentrations des sels nutritifs entre les couches profondes et de surface permettent de calculer la consommation annuelle, ! equivalente " a la production export! ee de l'! el! ement nutritif consid! er! e vers les couches profondes. Les r! esultats sont comparables pour les deux sc! enarios annuels ! etudi! es. La production export! ee de carbone pour les eaux de surface de la zone marginale de la glace, calcul! ee " a partir des consommations annuelles en nitrates et phosphates apr" es transformation gr# ace aux rapports de Redfield, est estim! ee " a 16-17 mmol C kg À1 yr À1 soit en moyenne 2174 g C m À2 yr À1 . La consommation annuelle de silicate est estim! ee " a 1.8 mol Si m À2 yr À1 , relativement ! elev! ee en *Corresponding author. Tel.: +49-421-2182931; fax: +49-421-2187018. E-mail address: hoppema@physik.uni-bremen.de (M. Hoppema).0967-0645/02/$ -see front matter r 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 7 -0 6 4 5 ( 0 2 ) 0 0 0 0 6 -1 comparaison des estimations ant! erieures. Le rapport molaire Si/C, voisin de 1 dans le mat! eriel export! e, traduit la dominance des diatom! ees dans l'export de mati" eres organiques.

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Section: Discussionmentioning

confidence: 99%

Annual export production in the interior Weddell Gyre estimated from a chemical mass balance of nutrients

Hoppema

Baar

Bellerby

et al. 2002

Deep Sea Research Part II: Topical Studies in Oceanography

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“…Phaeocystis is known to be critical with regard to biogeochemistry, climate feedbacks and food webs, but its food-web connections in the Ross Sea remain elusive. It produces large amounts of dimethylsulphide (DMS, a volatile organic that is transported great distances and can influence cloud formation; Andreae 1990), has greatly different ratios of particulate C : N : P relative to diatoms (Arrigo et al 1999;Sweeney et al 2000), is largely ungrazed (Smith & Asper 2001), and can export significant quantities of organic matter to depth via aggregate formation (Smith & Dunbar 1998;DiTullio et al 2000), although the majority of the biogenic material is remineralized within the water column (Smith & Asper 2000;Asper & Smith 2003). DMS derivatives, found in ice cores, have also become important proxies for pre-historical trends in ocean productivity (Curran et al 2003).…”

Section: The Biological Settingmentioning

confidence: 99%

Trophic interactions within the Ross Sea continental shelf ecosystem

Smith

Ainley

Cattaneo‐Vietti

2006

Phil. Trans. R. Soc. B

169

120

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The continental shelf of the Ross Sea is one of the Antarctic's most intensively studied regions. We review the available data on the region's physical characteristics (currents and ice concentrations) and their spatial variations, as well as components of the neritic food web, including lower and middle levels (phytoplankton, zooplankton, krill, fishes), the upper trophic levels (seals, penguins, pelagic birds, whales) and benthic fauna. A hypothetical food web is presented. Biotic interactions, such as the role of Euphausia crystallorophias and Pleuragramma antarcticum as grazers of lower levels and food for higher trophic levels, are suggested as being critical. The neritic food web contrasts dramatically with others in the Antarctic that appear to be structured around the keystone species Euphausia superba. Similarly, we suggest that benthic-pelagic coupling is stronger in the Ross Sea than in most other Antarctic regions. We also highlight many of the unknowns within the food web, and discuss the impacts of a changing Ross Sea habitat on the ecosystem.

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Interannual variability in vertical export in the Ross Sea: Magnitude, composition, and environmental correlates

Smith

Shields

Dreyer

et al. 2011

Deep Sea Research Part I: Oceanographic Research Papers

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A balanced nitrogen budget of the surface layer of the southern Ross Sea, Antarctica

Cited by 12 publications

References 22 publications

Annual export production in the interior Weddell Gyre estimated from a chemical mass balance of nutrients

Annual export production in the interior Weddell Gyre estimated from a chemical mass balance of nutrients

Trophic interactions within the Ross Sea continental shelf ecosystem

Interannual variability in vertical export in the Ross Sea: Magnitude, composition, and environmental correlates

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