scholarly journals Variations in contributions of dead copepods to vertical fluxes of particulate organic carbon in the Beaufort Sea

2020 ◽  
Vol 642 ◽  
pp. 67-81
Author(s):  
M Sampei ◽  
A Forest ◽  
L Fortier ◽  
T Yamamoto ◽  
H Hattori ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Marine Ecosystem ◽  
Beaufort Sea ◽  
Sediment Traps ◽  
Regional Variability ◽  
Carbon Export ◽  
Vertical Fluxes ◽  
Poc Flux ◽  
Flux Variability

Dead zooplankton, including crustaceans, are increasingly recognized as important agents of vertical carbon export from surface waters and in marine food webs. Quantifying the contribution of passively sinking copepods (PSCs) to vertical fluxes of total particulate organic carbon (POC) is important for understanding marine ecosystem carbon budgets. Information on this is limited because identifying PSCs in sediment trap samples is difficult. Generally, swimmers (undecomposed metazoans, including PSCs, caught in sediment traps) are removed from a trap sample before the POC content is measured, although ignoring PSCs causes the total POC flux to be significantly underestimated. We quantified temporal and regional variability in PSC flux and contribution of PSCs to total POC flux (PSCs + detrital sinking particles, generally analyzed to estimate detrital POC flux) at the Mackenzie Shelf margins in the Beaufort Sea. Six datasets were used to examine PSC flux variability at ~100 m depth, which is deeper than the winter pycnocline depth (30-50 m), at the continental margin. The average (±SD) annual PSC flux (1378 ± 662 mg C m-2 yr-1, n = 6 [datasets]) and PSC contribution to the total POC flux (21 ± 10%, n = 6) suggested that PSCs, especially Pareuchaeta glacialis, were important agents of POC export from the surface layer (~100 m) to deeper water at the inter-regional and multiyear scales. We propose a hypothesis that processes controlling PSC flux variability may vary seasonally, perhaps relating to life cycle (reproduction) in winter (February) and osmotic stress in July-October when the PSC flux is relatively high.

scholarly journals Calibration of sediment traps and particulate organic carbon export using 234 Th in the Barents Sea

2002 ◽  
Vol 80 (1) ◽  
pp. 11-26 ◽  
Author(s):  
L Coppola ◽  
M Roy-Barman ◽  
P Wassmann ◽  
S Mulsow ◽  
C Jeandel
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Barents Sea ◽  
Sediment Traps ◽  
Carbon Export ◽  
The Barents Sea

scholarly journals Global Ocean Particulate Organic Carbon Flux Merged with Satellite Parameters

2016 ◽  
Author(s):  
Colleen B. Mouw ◽  
Audrey Barnett ◽  
Galen A. McKinley ◽  
Lucas Gloege ◽  
Darren Pilcher
Keyword(s):  
Time Series ◽  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Net Primary Production ◽  
Mixed Layer Depth ◽  
Deep Ocean ◽  
Euphotic Zone ◽  
Sediment Traps ◽  
Global Ocean ◽  
Carbon Export

Abstract. Particulate organic carbon (POC) flux estimated from POC concentration observations from sediment traps and 234Th are compiled across the global ocean. The compilation includes six time series locations: CARIACO, K2, OSP, BATS, OFP and HOT. Efficiency of the biological pump of carbon to the deep ocean depends largely on biologically mediated export of carbon from the surface ocean and its remineralization with depth, thus biologically related parameters able to be estimated from satellite observations were merged at the POC observation sites. Satellite parameters include: net primary production, percent microplankton, sea surface temperature, photosynthetically active radiation, diffuse attenuation coefficient at 490 nm, euphotic zone depth, as well as, climatological mixed layer depth. 85 % of the observations across the globe are concentrated in the Northern Hemisphere with 44 % of the data record overlapping the satellite record. Time series sites accounted for 36 % of the data. 71 % of the data is measured at ≥ 500 m with the most common deployment depths between 1000 and 1500 m. This dataset is valuable for investigations of CO2 drawdown, carbon export, remineralization, and sequestration. The compiled data can be freely accessed at doi:10.1594/PANGAEA.855600.

scholarly journals Attenuation of sinking particulate organic carbon flux through the mesopelagic ocean

2015 ◽  
Vol 112 (4) ◽  
pp. 1089-1094 ◽  
Author(s):  
Chris M. Marsay ◽  
Richard J. Sanders ◽  
Stephanie A. Henson ◽  
Katsiaryna Pabortsava ◽  
Eric P. Achterberg ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Atmospheric Carbon Dioxide ◽  
Deep Ocean ◽  
Sediment Traps ◽  
Length Scale ◽  
Deep Sea Sediment ◽  
The North ◽  
Labile Fraction ◽  
Poc Flux

The biological carbon pump, which transports particulate organic carbon (POC) from the surface to the deep ocean, plays an important role in regulating atmospheric carbon dioxide (CO2) concentrations. We know very little about geographical variability in the remineralization depth of this sinking material and less about what controls such variability. Here we present previously unpublished profiles of mesopelagic POC flux derived from neutrally buoyant sediment traps deployed in the North Atlantic, from which we calculate the remineralization length scale for each site. Combining these results with corresponding data from the North Pacific, we show that the observed variability in attenuation of vertical POC flux can largely be explained by temperature, with shallower remineralization occurring in warmer waters. This is seemingly inconsistent with conclusions drawn from earlier analyses of deep-sea sediment trap and export flux data, which suggest lowest transfer efficiency at high latitudes. However, the two patterns can be reconciled by considering relatively intense remineralization of a labile fraction of material in warm waters, followed by efficient downward transfer of the remaining refractory fraction, while in cold environments, a larger labile fraction undergoes slower remineralization that continues over a longer length scale. Based on the observed relationship, future increases in ocean temperature will likely lead to shallower remineralization of POC and hence reduced storage of CO2 by the ocean.

scholarly journals Export fluxes in a naturally iron-fertilized area of the Southern Ocean – Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap

2015 ◽  
Vol 12 (11) ◽  
pp. 3153-3170 ◽  
Author(s):  
M. Rembauville ◽  
I. Salter ◽  
N. Leblond ◽  
A. Gueneugues ◽  
S. Blain
Keyword(s):  
Organic Carbon ◽  
Southern Ocean ◽  
Particulate Organic Carbon ◽  
Sediment Trap ◽  
Time Lag ◽  
Deep Ocean ◽  
Companion Paper ◽  
Grazing Pressure ◽  
Carbon Export ◽  
Poc Flux

Abstract. A sediment trap moored in the naturally iron-fertilized Kerguelen Plateau in the Southern Ocean provided an annual record of particulate organic carbon and nitrogen fluxes at 289 m. At the trap deployment depth, current speeds were typically low (~ 10 cm s−1) and primarily tidal-driven (M2 tidal component). Although advection was weak, the sediment trap may have been subject to hydrodynamical and biological (swimmer feeding on trap funnel) biases. Particulate organic carbon (POC) flux was generally low (< 0.5 mmol m−2 d−1), although two episodic export events (< 14 days) of 1.5 mmol m−2 d−1 were recorded. These increases in flux occurred with a 1-month time lag from peaks in surface chlorophyll and together accounted for approximately 40% of the annual flux budget. The annual POC flux of 98.2 ± 4.4 mmol m−2 yr−1 was low considering the shallow deployment depth but comparable to independent estimates made at similar depths (~ 300 m) over the plateau, and to deep-ocean (> 2 km) fluxes measured from similarly productive iron-fertilized blooms. Although undertrapping cannot be excluded in shallow moored sediment trap deployment, we hypothesize that grazing pressure, including mesozooplankton and mesopelagic fishes, may be responsible for the low POC flux beneath the base of the winter mixed layer. The importance of plankton community structure in controlling the temporal variability of export fluxes is addressed in a companion paper.

scholarly journals Global database of ratios of particulate organic carbon to thorium-234 in the ocean: improving estimates of the biological carbon pump

2020 ◽  
Vol 12 (2) ◽  
pp. 1267-1285 ◽  
Author(s):  
Viena Puigcorbé ◽  
Pere Masqué ◽  
Frédéric A. C. Le Moigne
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Mixed Layer Depth ◽  
Sediment Traps ◽  
Data Repository ◽  
The South ◽  
South Indian ◽  
Wide Range ◽  
Carbon Pump ◽  
Biological Carbon Pump

Abstract. The ocean's biological carbon pump (BCP) plays a major role in the global carbon cycle. A fraction of the photosynthetically fixed organic carbon produced in surface waters is exported below the sunlit layer as settling particles (e.g., marine snow). Since the seminal works on the BCP, global estimates of the global strength of the BCP have improved but large uncertainties remain (from 5 to 20 Gt C yr−1 exported below the euphotic zone or mixed-layer depth). The 234Th technique is widely used to measure the downward export of particulate organic carbon (POC). This technique has the advantage of allowing a downward flux to be determined by integrating the deficit of 234Th in the upper water column and coupling it to the POC∕234Th ratio in sinking particles. However, the factors controlling the regional, temporal, and depth variations of POC∕234Th ratios are poorly understood. We present a database of 9318 measurements of the POC∕234Th ratio in the ocean, from the surface down to >5500 m, sampled on three size fractions (∼>0.7 µm, ∼1–50 µm, ∼>50 µm), collected with in situ pumps and bottles, and also from bulk particles collected with sediment traps. The dataset is archived in the data repository PANGAEA® under https://doi.org/10.1594/PANGAEA.911424 (Puigcorbé, 2019). The samples presented in this dataset were collected between 1989 and 2018, and the data have been obtained from published papers and open datasets available online. Unpublished data have also been included. Multiple measurements can be found in most of the open ocean provinces. However, there is an uneven distribution of the data, with some areas highly sampled (e.g., China Sea, Bermuda Atlantic Time Series station) compared to some others that are not well represented, such as the southeastern Atlantic, the south Pacific, and the south Indian oceans. Some coastal areas, although in a much smaller number, are also included in this global compilation. Globally, based on different depth horizons and climate zones, the median POC∕234Th ratios have a wide range, from 0.6 to 18 µmol dpm−1.

234Th-derived particulate organic carbon export in the Prydz Bay, Antarctica

2013 ◽  
Vol 299 (1) ◽  
pp. 621-630 ◽  
Author(s):  
Hao Ma ◽  
Zhi Zeng ◽  
Jianhua He ◽  
Zhengbing Han ◽  
Wuhui Lin ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Prydz Bay ◽  
Carbon Export

scholarly journals Variability in efficiency of particulate organic carbon export: A model study

2015 ◽  
Vol 29 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Stephanie A. Henson ◽  
Andrew Yool ◽  
Richard Sanders
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Carbon Export ◽  
Model Study

234Th-derived particulate organic carbon export flux in the western Arctic Ocean

2010 ◽  
Vol 28 (6) ◽  
pp. 1146-1151 ◽  
Author(s):  
Wen Yu ◽  
Liqi Chen ◽  
Jianping Cheng ◽  
Jianhua He ◽  
Mingduan Yin ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Arctic Ocean ◽  
Particulate Organic Carbon ◽  
Carbon Export ◽  
Western Arctic Ocean ◽  
Export Flux ◽  
Western Arctic
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