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Ocean productivity south of Australia during spring and summer


Bender, ML and Tilbrook, B and Cassar, N and Jonsson, B and Poisson, A and Trull, TW, Ocean productivity south of Australia during spring and summer, Deep-Sea Research I, 112 pp. 68-78. ISSN 0967-0637 (2016) [Refereed Article]

Copyright Statement

Copyright 2016 Elsevier Ltd.

DOI: doi:10.1016/j.dsr.2016.02.018


We estimated mixed layer gross and net community production on a total of 20 crossings in the Australian sector of the Southern Ocean during the summer half-years (October–March) of 2007–2010. These estimates were calculated from measurements of O2/Ar ratios and triple isotope compositions of O2 in ∼250 seawater samples collected underway. For comparison purposes, we also measured the seasonal drawdown of mixed layer NO-3 and SiO2 concentrations during 2006–2007 and 2007–2008. Across all samples, average values of gross and net O2 production (measured by O2/Ar and O2 isotopes), were about 86 ± 90 and 18 ± 17 mmol O2 m−2 day−1, respectively. Gross production was highest at the Subtropical Front (up to ∼230 mmol O2 m−2 day−1), and decreased southward (to ~10 near the southern boundary of the Antarctic Circumpolar Current). In contrast, net community production showed little meridional variation. Net and gross O2 production increased throughout the spring-to-fall period, although most SiO2 drawdown occurred in December. Consistent with satellite chlorophyll estimates, we saw no evidence for an intense spring bloom (e.g. as has been observed in the North Atlantic). Volumetric net and gross O2 production in the mixed layer, normalized to chlorophyll, increased (with considerable scatter) with average irradiance in the mixed layer. These relationships provide a basis for estimating production from Argo float data and properties observed by satellite.

Item Details

Item Type:Refereed Article
Keywords:Southern Ocean, marine productivity, dissolved gas tracers
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Chemical oceanography
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Measurement and assessment of marine water quality and condition
UTAS Author:Tilbrook, B (Dr Bronte Tilbrook)
UTAS Author:Trull, TW (Professor Thomas Trull)
ID Code:113773
Year Published:2016
Web of Science® Times Cited:6
Deposited By:Ecology and Biodiversity
Deposited On:2017-01-19
Last Modified:2018-04-30

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