Regional-scale algorithm to estimate the particulate organic carbon (POC) in inland waters using Landsat-5/TM images

Abstract. Measurements of gaseous and particulate organic carbon were performed during the MEGAPOLI experiments, in July 2009 and January–February 2010, at the SIRTA observatory in suburban Paris. Measurements comprise primary and secondary volatile organic compounds (VOCs), of both anthropogenic and biogenic origins, including C12–C16 n-alkanes of intermediate volatility (IVOCs), suspected to be efficient precursors of secondary organic aerosol (SOA). The time series of gaseous carbon are generally consistent with times series of particulate organic carbon at regional scale, and are clearly affected by meteorology and air mass origin. Concentration levels of anthropogenic VOCs in urban and suburban Paris were surprisingly low (2–963 ppt) compared to other megacities worldwide and to rural continental sites. Urban enhancement ratios of anthropogenic VOC pairs agree well between the urban and suburban Paris sites, showing the regional extent of anthropogenic sources of similar composition. Contrary to other primary anthropogenic VOCs (aromatics and alkanes), IVOCs showed lower concentrations in winter (< 5 ppt) compared to summer (13–27 ppt), which cannot be explained by the gas-particle partitioning theory. Higher concentrations of most oxygenated VOCs in winter (18–5984 ppt) suggest their dominant primary anthropogenic origin. The respective role of primary anthropogenic gaseous compounds in regional SOA formation was investigated by estimating the SOA mass concentration expected from the anthropogenic VOCs and IVOCs (I / VOCs) measured at SIRTA. From an integrated approach based on emission ratios and SOA yields, 38 % of the SOA measured at SIRTA is explained by the measured concentrations of I / VOCs, with a 2% contribution by C12–C16 n-alkane IVOCs. From the results of an alternative time-resolved approach, the average IVOC contribution to SOA formation is estimated to be 7%, which is half of the average contribution of the traditional aromatic compounds (15%). Both approaches, which are based on in situ observations of particular I / VOCs, emphasize the importance of the intermediate volatility compounds in the SOA formation, and support previous results from chamber experiments and modeling studies. They also support the need to make systematic the IVOCs' speciated measurement during field campaigns.

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Variability of particulate organic carbon in inland waters observed from MODIS Aqua imagery

Environmental Research Letters ◽

10.1088/1748-9326/9/8/084011 ◽

2014 ◽

Vol 9 (8) ◽

pp. 084011 ◽

Cited By ~ 29

Author(s):

Hongtao Duan ◽

Lian Feng ◽

Ronghua Ma ◽

Yuchao Zhang ◽

Steven Arthur Loiselle

Keyword(s):

Organic Carbon ◽

Particulate Organic Carbon ◽

Inland Waters

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Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters

10.5194/bg-2017-68 ◽

2017 ◽

Cited By ~ 1

Author(s):

Changchun Huang ◽

Lin Yao ◽

Hao Yang ◽

Chen Lin ◽

Tao Huang ◽

...

Keyword(s):

Organic Carbon ◽

Particulate Organic Carbon ◽

Inland Waters ◽

Mean Values ◽

Inland Water ◽

Carbon And Nitrogen ◽

Average Value ◽

The Mean ◽

The Relationship ◽

Global Carbon

Abstract. We examined the relationship between, and variations in, particulate organic carbon (POC) and particulate organic nitrogen (PON) based on previously acquired ocean and inland water data. Some new points were found beside the traditional latitude, depth and temperature dependence of POC, PON and POC/PON. The global average value of POC/PON (7.54±3.82) is higher than the Redfield ratio (6.63). The mean values of POC/PON in south and north hemisphere are 7.40±3.83 and 7.80±3.92, respectively. The high values of POC/PON appeared between 80° N~90° N (12.2±7.5) and 70° N~80° N (9.4±6.4), and relatively low POC/PON were found from 20 °N (6.6±2.8) to 40 °N (6.7±2.7). The latitudinal dependency of POC/PON in the northern hemisphere is much stronger than in the southern hemisphere. Variations of POC/PON in inland water also showed similar latitude-dependency of POC/PON in ocean water, but significantly regulated by lake’s morphology, trophic state and climate, etc. factors. Higher POC and PON could be expected in the coastal water, while POC/PON significantly increased from 6.89±2.38 to 7.59±4.22 in north hemisphere with the increasing rate of 0.0024/km. The coupling relationship between POC and PON in oceans is much stronger than in inland waters. Variations in POC, PON and POC/PON in inland waters should receive more attention due to the importance of these values to global carbon and nitrogen cycles and the indeterminacy of the relationship between POC and PON.

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Siberian Arctic inland waters emit mostly contemporary carbon

10.5194/egusphere-egu2020-17416 ◽

2020 ◽

Author(s):

Joshua Dean ◽

Ove Meisel ◽

Melanie Martyn Roscoe ◽

Luca Belelli Marchesini ◽

Mark Garnett ◽

...

Keyword(s):

Organic Carbon ◽

Particulate Organic Carbon ◽

Carbon Emissions ◽

Carbon Sink ◽

Inland Waters ◽

Terrestrial Carbon ◽

Study Region ◽

Inland Water ◽

Radiocarbon Age ◽

Thawing Permafrost

Inland waters (rivers, lakes and ponds) are important conduits for the emission of terrestrial carbon in Arctic permafrost landscapes. These emissions are driven by turnover of contemporary terrestrial carbon and additional &#8220;pre-aged&#8221; (Holocene and late-Pleistocene) carbon released from thawing permafrost soils, but the magnitude of these source contributions to total inland water carbon fluxes remains unknown. Here we present unique simultaneous radiocarbon age measurements of inland water CO2, CH4 and dissolved and particulate organic carbon in northeast Siberia during summer. We show that >80% of total inland water carbon emissions were contemporary in age, but that pre-aged carbon contributed >50% at sites strongly affected by permafrost thaw. CO2 and CH4 were younger than dissolved and particulate organic carbon, suggesting emissions were primarily fuelled by contemporary carbon decomposition. The study region was a net carbon sink (-876.9 &#177; 136.4 Mg C for 25 July to 17 August), but inland waters were a source of contemporary (16.8 Mg C) and pre-aged (3.7 Mg C) emissions that respectively offset 1.9 &#177; 1.2% and 0.4 &#177; 0.3% of CO2 uptake by tundra (&#8209;897 &#177; 115 Mg C). Our findings reveal that inland water carbon emissions from permafrost landscapes may be more sensitive to changes in contemporary carbon turnover than the release of pre-aged carbon from thawing permafrost.

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Variation pattern of particulate organic carbon and nitrogen in oceans and inland waters

Biogeosciences ◽

10.5194/bg-15-1827-2018 ◽

2018 ◽

Vol 15 (6) ◽

pp. 1827-1841 ◽

Cited By ~ 9

Author(s):

Changchun Huang ◽

Quanliang Jiang ◽

Ling Yao ◽

Hao Yang ◽

Chen Lin ◽

...

Keyword(s):

Organic Carbon ◽

Particulate Organic Carbon ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Inland Waters ◽

Terrestrial Organic Matter ◽

Low Latitude ◽

Large Lakes ◽

Carbon And Nitrogen ◽

The Relationship

Abstract. We examined the relationship between, and variations in, particulate organic carbon (POC) and particulate organic nitrogen (PON) based on previously acquired ocean and inland water data. The latitudinal dependency of POC ∕ PON is significant between 20 and 90∘ N but weak in low-latitude areas and in the Southern Hemisphere. The mean values of POC ∕ PON in the Southern Hemisphere and Northern Hemisphere were 7.40±3.83 and 7.80±3.92, respectively. High values of POC ∕ PON appeared between 80–90 (12.2±7.5) and 70–80∘ N (9.4±6.4), while relatively low POC ∕ PON was found from 20 (6.6±2.8) to 40∘ N (6.7±2.7). The latitudinal variation of POC ∕ PON in the Northern Hemisphere is much stronger than in the Southern Hemisphere due to the influence of more terrestrial organic matter. Higher POC and PON could be expected in coastal waters. POC ∕ PON growth ranged from 6.89±2.38 to 7.59±4.22 in the Northern Hemisphere, with an increasing rate of 0.0024 km from the coastal to open ocean. Variations of POC ∕ PON in lake water also showed a similar latitude-variation tendency of POC ∕ PON with ocean water but were significantly regulated by the lakes' morphology, trophic state and climate. Small lakes and high-latitude lakes prefer relatively high POC ∕ PON, and large lakes and low-latitude lakes tend to prefer low POC ∕ PON. The coupling relationship between POC and PON in oceans is much stronger than in inland waters. Variations in POC, PON and POC ∕ PON in inland waters should receive more attention due to the implications of these values for the global carbon and nitrogen cycles and the indeterminacy of the relationship between POC and PON.

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Contribution of transparent exopolymeric particles (TEP) to estuarine particulate organic carbon pool

Marine Ecology Progress Series ◽

10.3354/meps11294 ◽

2015 ◽

Vol 529 ◽

pp. 17-34 ◽

Cited By ~ 12

Author(s):

S Annane ◽

L St-Amand ◽

M Starr ◽

E Pelletier ◽

GA Ferreyra

Keyword(s):

Organic Carbon ◽

Particulate Organic Carbon ◽

Carbon Pool ◽

Organic Carbon Pool ◽

Transparent Exopolymeric Particles

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The Carbon:²³⁴Thorium ratios of sinking particles in the California Current Ecosystem 2: Examination of a thorium sorption, desorption, and particle transport model

10.26434/chemrxiv.7803698 ◽

2019 ◽

Author(s):

Michael Stukel ◽

Thomas Kelly

Keyword(s):

Organic Carbon ◽

Water Column ◽

Particulate Organic Carbon ◽

Transport Model ◽

California Current ◽

In Situ Measurements ◽

Power Law Distribution ◽

Sinking Particles ◽

Organic Carbon Concentration

Thorium-234 (234Th) is a powerful tracer of particle dynamics and the biological pump in the surface ocean; however, variability in carbon:thorium ratios of sinking particles adds substantial uncertainty to estimates of organic carbon export. We coupled a mechanistic thorium sorption and desorption model to a one-dimensional particle sinking model that uses realistic particle settling velocity spectra. The model generates estimates of 238U-234Th disequilibrium, particulate organic carbon concentration, and the C:234Th ratio of sinking particles, which are then compared to in situ measurements from quasi-Lagrangian studies conducted on six cruises in the California Current Ecosystem. Broad patterns observed in in situ measurements, including decreasing C:234Th ratios with depth and a strong correlation between sinking C:234Th and the ratio of vertically-integrated particulate organic carbon (POC) to vertically-integrated total water column 234Th, were accurately recovered by models assuming either a power law distribution of sinking speeds or a double log normal distribution of sinking speeds. Simulations suggested that the observed decrease in C:234Th with depth may be driven by preferential remineralization of carbon by particle-attached microbes. However, an alternate model structure featuring complete consumption and/or disaggregation of particles by mesozooplankton (e.g. no preferential remineralization of carbon) was also able to simulate decreasing C:234Th with depth (although the decrease was weaker), driven by 234Th adsorption onto slowly sinking particles. Model results also suggest that during bloom decays C:234Th ratios of sinking particles should be higher than expected (based on contemporaneous water column POC), because high settling velocities minimize carbon remineralization during sinking.

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