Abstract
Samples for total organic carbon (TOC) analysis were collected on WOCE Line P15S (0°to 67°S along 170°W) and from 53°to 67°S along 170°E in the western South Pacific, and on Line I8 (5°N to 43°S along 80°/90°E) in the central Indian Ocean. TOC concentrations in the upper ocean varied greatly between the regions studied. Highest surface TOC concentrations (81-85 μM C and 68-73 μM C) were observed in the warmest waters (> 27°C) of the western South Pacific and central Indian Oceans, respectively. Lowest Surface TOC concentrations (45-65 μM C) were recorded in the southernmost waters occupied (> 50°S along 170°W and 170°E). Deep Water (> 1000 m) TOC concentrations were uniform across all regions analyzed, averaging between 42.3 and 43 μM C (SD: ± 0.9 μM C). Mixing between TOC-rich surface waters and TOC-poor deep waters was indicated by the strong correlations between TOC and temperature (r2 > 0.80, north of 45°S) and TOC and density (r2> 0.50, southernmost regions). TOC Was inversely correlated with-apparent oxygen utilization (AOU) along isopycnal surfaces north of the Polar Frontal Zone (PFZ) and at depths < 500 m. The TOC:AOU molar ratios at densities of σ(τ) 23-27 ranged from -0.15 to -0.34 in the South Pacific and from -0.13 to -0.31 in the Indian Ocean. These ratios indicate that TOC oxidation was responsible for 21%-47% and 18%-43% of oxygen consumption in the upper South Pacific and Indian Oceans, respectively. At greater depths, TOC did not contribute to the development of AOU. There was no evidence for significant export of dissolved and suspended organic carbon along isopycnal surfaces that ventilate near the PFZ. (C) 2000 Elsevier Science B.V.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 249-264 |
| Number of pages | 16 |
| Journal | Marine Chemistry |
| Volume | 68 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jan 2000 |
| Externally published | Yes |
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Keywords
- Apparent oxygen utilization
- Central Indian Ocean
- Dissolved organic carbon
- Total organic carbon
- Western South Pacific Ocean
ASJC Scopus subject areas
- Chemistry(all)
- Oceanography
Cite this
Organic carbon and apparent oxygen utilization in the western South Pacific and the central Indian Oceans. / Doval, M. D.; Hansell, Dennis A.
In: Marine Chemistry, Vol. 68, No. 3, 01.2000, p. 249-264.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Organic carbon and apparent oxygen utilization in the western South Pacific and the central Indian Oceans
AU - Doval, M. D.
AU - Hansell, Dennis A
PY - 2000/1
Y1 - 2000/1
N2 - Samples for total organic carbon (TOC) analysis were collected on WOCE Line P15S (0°to 67°S along 170°W) and from 53°to 67°S along 170°E in the western South Pacific, and on Line I8 (5°N to 43°S along 80°/90°E) in the central Indian Ocean. TOC concentrations in the upper ocean varied greatly between the regions studied. Highest surface TOC concentrations (81-85 μM C and 68-73 μM C) were observed in the warmest waters (> 27°C) of the western South Pacific and central Indian Oceans, respectively. Lowest Surface TOC concentrations (45-65 μM C) were recorded in the southernmost waters occupied (> 50°S along 170°W and 170°E). Deep Water (> 1000 m) TOC concentrations were uniform across all regions analyzed, averaging between 42.3 and 43 μM C (SD: ± 0.9 μM C). Mixing between TOC-rich surface waters and TOC-poor deep waters was indicated by the strong correlations between TOC and temperature (r2 > 0.80, north of 45°S) and TOC and density (r2> 0.50, southernmost regions). TOC Was inversely correlated with-apparent oxygen utilization (AOU) along isopycnal surfaces north of the Polar Frontal Zone (PFZ) and at depths < 500 m. The TOC:AOU molar ratios at densities of σ(τ) 23-27 ranged from -0.15 to -0.34 in the South Pacific and from -0.13 to -0.31 in the Indian Ocean. These ratios indicate that TOC oxidation was responsible for 21%-47% and 18%-43% of oxygen consumption in the upper South Pacific and Indian Oceans, respectively. At greater depths, TOC did not contribute to the development of AOU. There was no evidence for significant export of dissolved and suspended organic carbon along isopycnal surfaces that ventilate near the PFZ. (C) 2000 Elsevier Science B.V.
AB - Samples for total organic carbon (TOC) analysis were collected on WOCE Line P15S (0°to 67°S along 170°W) and from 53°to 67°S along 170°E in the western South Pacific, and on Line I8 (5°N to 43°S along 80°/90°E) in the central Indian Ocean. TOC concentrations in the upper ocean varied greatly between the regions studied. Highest surface TOC concentrations (81-85 μM C and 68-73 μM C) were observed in the warmest waters (> 27°C) of the western South Pacific and central Indian Oceans, respectively. Lowest Surface TOC concentrations (45-65 μM C) were recorded in the southernmost waters occupied (> 50°S along 170°W and 170°E). Deep Water (> 1000 m) TOC concentrations were uniform across all regions analyzed, averaging between 42.3 and 43 μM C (SD: ± 0.9 μM C). Mixing between TOC-rich surface waters and TOC-poor deep waters was indicated by the strong correlations between TOC and temperature (r2 > 0.80, north of 45°S) and TOC and density (r2> 0.50, southernmost regions). TOC Was inversely correlated with-apparent oxygen utilization (AOU) along isopycnal surfaces north of the Polar Frontal Zone (PFZ) and at depths < 500 m. The TOC:AOU molar ratios at densities of σ(τ) 23-27 ranged from -0.15 to -0.34 in the South Pacific and from -0.13 to -0.31 in the Indian Ocean. These ratios indicate that TOC oxidation was responsible for 21%-47% and 18%-43% of oxygen consumption in the upper South Pacific and Indian Oceans, respectively. At greater depths, TOC did not contribute to the development of AOU. There was no evidence for significant export of dissolved and suspended organic carbon along isopycnal surfaces that ventilate near the PFZ. (C) 2000 Elsevier Science B.V.
KW - Apparent oxygen utilization
KW - Central Indian Ocean
KW - Dissolved organic carbon
KW - Total organic carbon
KW - Western South Pacific Ocean
UR - http://www.scopus.com/inward/record.url?scp=0033973628&partnerID=8YFLogxK
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U2 - 10.1016/S0304-4203(99)00081-X
DO - 10.1016/S0304-4203(99)00081-X
M3 - Article
VL - 68
SP - 249
EP - 264
JO - Marine Chemistry
JF - Marine Chemistry
SN - 0304-4203
IS - 3
ER -