scholarly journals Sea-air CO<sub>2</sub> flux estimated from SOCAT surface-ocean CO<sub>2</sub> partial pressure data and atmospheric CO<sub>2</sub> mixing ratio data

2012 ◽  
Vol 9 (3) ◽  
pp. 2273-2326 ◽  
Author(s):  
C. Rödenbeck ◽  
R. F. Keeling ◽  
D. C. E. Bakker ◽  
N. Metzl ◽  
A. Olsen ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Carbon Sources ◽  
Co2 Flux ◽  
Atmospheric Co2 ◽  
Diagnostic Model ◽  
Pressure Data ◽  
Co2 Partial Pressure ◽  
Sources And Sinks ◽  
Surface Ocean ◽  
Spatio Temporal

Abstract. Surface-ocean CO2 partial pressure data have been assimilated into a simple diagnostic model of surface-ocean biogeochemistry to estimate the spatio-temporal CO2 partial pressure field and ultimately the sea-air CO2 fluxes. Results compare well with the widely used monthly climatology by Takahashi et al. (2009) but also contain some short-term and interannual variations. Fitting the same model to atmospheric CO2 data yields less robust but consistent estimates, confirming that using the partial pressure based estimates as ocean prior in atmospheric CO2 inversions may improve land CO2 flux estimates. Estimated seasonality of ocean-internal carbon sources and sinks is discussed in the light of observed nutrient variations.

scholarly journals Global surface-ocean <i>p</i><sup>CO<sub>2</sub></sup> and sea–air CO<sub>2</sub> flux variability from an observation-driven ocean mixed-layer scheme

Ocean Science ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. 193-216 ◽  
Author(s):  
C. Rödenbeck ◽  
R. F. Keeling ◽  
D. C. E. Bakker ◽  
N. Metzl ◽  
A. Olsen ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Mixed Layer ◽  
Co2 Flux ◽  
Companion Paper ◽  
Diagnostic Model ◽  
Ocean Mixed Layer ◽  
Co2 Partial Pressure ◽  
Surface Ocean ◽  
Flux Variability ◽  
Global Surface

Abstract. A temporally and spatially resolved estimate of the global surface-ocean CO2 partial pressure field and the sea–air CO2 flux is presented, obtained by fitting a simple data-driven diagnostic model of ocean mixed-layer biogeochemistry to surface-ocean CO2 partial pressure data from the SOCAT v1.5 database. Results include seasonal, interannual, and short-term (daily) variations. In most regions, estimated seasonality is well constrained from the data, and compares well to the widely used monthly climatology by Takahashi et al. (2009). Comparison to independent data tentatively supports the slightly higher seasonal variations in our estimates in some areas. We also fitted the diagnostic model to atmospheric CO2 data. The results of this are less robust, but in those areas where atmospheric signals are not strongly influenced by land flux variability, their seasonality is nevertheless consistent with the results based on surface-ocean data. From a comparison with an independent seasonal climatology of surface-ocean nutrient concentration, the diagnostic model is shown to capture relevant surface-ocean biogeochemical processes reasonably well. Estimated interannual variations will be presented and discussed in a companion paper.

scholarly journals Interannual sea–air CO<sub>2</sub> flux variability from an observation-driven ocean mixed-layer scheme

2014 ◽  
Vol 11 (17) ◽  
pp. 4599-4613 ◽  
Author(s):  
C. Rödenbeck ◽  
D. C. E. Bakker ◽  
N. Metzl ◽  
A. Olsen ◽  
C. Sabine ◽  
...  
Keyword(s):  
Southern Oscillation ◽  
Atmospheric Oxygen ◽  
Large Fraction ◽  
Co2 Flux ◽  
Co2 Exchange ◽  
Co2 Partial Pressure ◽  
Surface Ocean ◽  
The North ◽  
Ocean Carbon ◽  
Carbon Dioxide Co2

Abstract. Interannual anomalies in the sea–air carbon dioxide (CO2) exchange have been estimated from surface-ocean CO2 partial pressure measurements. Available data are sufficient to constrain these anomalies in large parts of the tropical and North Pacific and in the North Atlantic, in some areas covering the period from the mid 1980s to 2011. Global interannual variability is estimated as about 0.31 Pg C yr−1 (temporal standard deviation 1993–2008). The tropical Pacific accounts for a large fraction of this global variability, closely tied to El Niño–Southern Oscillation (ENSO). Anomalies occur more than 6 months later in the east than in the west. The estimated amplitude and ENSO response are roughly consistent with independent information from atmospheric oxygen data. This both supports the variability estimated from surface-ocean carbon data and demonstrates the potential of the atmospheric oxygen signal to constrain ocean biogeochemical processes. The ocean variability estimated from surface-ocean carbon data can be used to improve land CO2 flux estimates from atmospheric inversions.

scholarly journals CO<sub>2</sub> partial pressure and CO<sub>2</sub> emission along the lower Red River (Vietnam)

2018 ◽  
Vol 15 (15) ◽  
pp. 4799-4814 ◽  
Author(s):  
Thi Phuong Quynh Le ◽  
Cyril Marchand ◽  
Cuong Tu Ho ◽  
Nhu Da Le ◽  
Thi Thuy Duong ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Co2 Flux ◽  
River System ◽  
Water Quality Monitoring ◽  
Red River ◽  
Wet Season ◽  
Night Time ◽  
Co2 Partial Pressure ◽  
The Difference ◽  
Hoa Binh

Abstract. The Red River (Vietnam) is representative of a south-east Asian river system, strongly affected by climate and human activities. This study aims to quantify the spatial and seasonal variability of CO2 partial pressure and CO2 emissions of the lower Red River system. Water quality monitoring and riverine pCO2 measurements were carried out for 24 h at five stations distributed along the lower Red River system during the dry and the wet seasons. The riverine pCO2 was supersaturated relative to the atmospheric equilibrium (400 ppm), averaging about 1589±43 ppm and resulting in a water–air CO2 flux of 530.3±16.9 mmol m−2 d−1 for the lower Red River. pCO2 and CO2 outgassing rates were characterized by significant spatial variation along this system, with the highest values measured at Hoa Binh station, located downstream of the Hoa Binh Dam, on the Da River. Seasonal pCO2 and CO2 outgassing rate variations were also observed, with higher values measured during the wet season at almost all sites. The higher river discharges, enhanced external inputs of organic matter from watersheds and direct inputs of CO2 from soils or wetland were responsible for higher pCO2 and CO2 outgassing rates. The difference in pCO2 between the daytime and the night-time was not significant, suggesting weak photosynthesis processes in the water column of the Red River due to its high sediment load.

scholarly journals Forest stand age information improves an inverse North American carbon flux estimate

2013 ◽  
Vol 10 (3) ◽  
pp. 4781-4817 ◽  
Author(s):  
F. Deng ◽  
J. M. Chen ◽  
Y. Pan ◽  
W. Peters ◽  
R. Birdsey ◽  
...  
Keyword(s):  
Carbon Flux ◽  
Age Factors ◽  
Carbon Sources ◽  
Co2 Flux ◽  
Forest Stand ◽  
Atmospheric Co2 ◽  
Stand Age ◽  
Ecosystem Carbon ◽  
Net Ecosystem Carbon Exchange ◽  
Carbon Dioxide Co2

Abstract. Atmospheric inversions have become an important tool in quantifying carbon dioxide (CO2) sinks and sources at a variety of spatiotemporal scales, but associated large uncertainties restrain the inversion research community from reaching agreements on many important subjects. We enhanced an atmospheric inversion of the CO2 flux for North America by introducing spatially-explicit information on forest stand age for US and Canada as an additional constraint, since forest carbon dynamics are closely related to time since disturbance. To use stand age information in the inversion, we converted stand age into an age factor, and included the covariances between sub-continental regions in the inversion based on the similarity of the age factors. Our inversion results show that, considering age factors, regions with recently-disturbed or old forests are often nudged towards carbon sources, while regions with middle-aged productive forests are shifted towards sinks. This conforms to stand age effects observed in flux networks. At the sub-continental level, our inverted carbon fluxes agree well with continuous estimates of net ecosystem carbon exchange (NEE) upscaled from eddy covariance flux data (EC) based on MODIS data. Inverted fluxes with the age constraint exhibit stronger correlation to these upscaled NEE estimates than those inverted without the age constraint. While the carbon flux at the continental and sub-continental scales is predominantly determined by atmospheric CO2 observations, the age constraint is shown to have potential to improve the inversion of the carbon flux distribution among sub-continental regions, especially for regions lacking atmospheric CO2 observations.

scholarly journals Interannual sea–air CO<sub>2</sub> flux variability from an observation-driven ocean mixed-layer scheme

2014 ◽  
Vol 11 (2) ◽  
pp. 3167-3207 ◽  
Author(s):  
C. Rödenbeck ◽  
D. C. E. Bakker ◽  
N. Metzl ◽  
A. Olsen ◽  
C. Sabine ◽  
...  
Keyword(s):  
Atmospheric Oxygen ◽  
Large Fraction ◽  
Co2 Flux ◽  
Co2 Exchange ◽  
Co2 Partial Pressure ◽  
Surface Ocean ◽  
Independent Information ◽  
Northern Pacific ◽  
Ocean Carbon ◽  
Carbon Dioxide Co2

Abstract. Interannual anomalies in the sea–air carbon dioxide (CO2) exchange have been estimated from surface-ocean CO2 partial pressure measurements. Available data are sufficient to constrain these anomalies in large parts of the tropical and Northern Pacific and in the Northern Atlantic, in some areas since the mid 1980s to 2011. Global interannual variability is estimated as about 0.31 Pg C yr−1 (temporal standard deviation 1993–2008). The tropical Pacific accounts for a large fraction of this global variability, closely tied to ENSO. Anomalies occur more than 6 months later in the East than in the West. The estimated amplitude and ENSO response are consistent with independent information from atmospheric oxygen data. Despite discrepancies in detail, this both supports the variability estimated from surface-ocean carbon data, and demonstrates the potential of the atmospheric oxygen signal to constrain ocean biogeochemical processes. The ocean variability estimated from surface-ocean carbon data can be used to improve land CO2 flux estimates from atmospheric inversions.

scholarly journals Data-based estimates of interannual sea–air CO<sub>2</sub> flux variations 1957–2020 and their relation to environmental drivers

2021 ◽  
Author(s):  
Christian Rödenbeck ◽  
Tim DeVries ◽  
Judith Hauck ◽  
Corinne Le Quéré ◽  
Ralph Keeling
Keyword(s):  
Wind Speed ◽  
Linear Regression ◽  
Mixed Layer ◽  
Carbon Sources ◽  
Co2 Flux ◽  
Mapping Method ◽  
Atmospheric Co2 ◽  
Environmental Drivers ◽  
Multi Linear Regression ◽  
Secular Increase

Abstract. This study considers year-to-year and decadal variations as well as secular trends of the sea–air CO2 flux over the 1957–2020 period, as constrained by the pCO2 measurements from the SOCAT data base. In a first step, we relate interannual anomalies in ocean-internal carbon sources and sinks to local interannual anomalies in sea surface temperature (SST), the temporal changes of SST (dSST/dt), and squared wind speed (u2), employing a multi-linear regression. In the tropical Pacific, we find interannual variability to be dominated by dSST/dt, as arising from variations in the upwelling of colder and more carbon-rich waters into the mixed layer. In the eastern upwelling zones as well as in circumpolar bands in the high latitudes of both hemispheres, we find sensitivity to wind speed, compatible with the entrainment of carbon-rich water during wind-driven deepening of the mixed layer and wind-driven upwelling. In the Southern Ocean, the secular increase in wind speed leads to a secular increase in the carbon source into the mixed layer, with an estimated reduction of the sink trend in the range 17 to 42 %. In a second step, we combined the result of the multi-linear regression and an explicitly interannual pCO2-based additive correction into a “hybrid” estimate of the sea–air CO2 flux over the period 1957–2020. As a pCO2 mapping method, it combines (a) the ability of a regression to bridge data gaps and extrapolate into the early decades almost void of pCO2 data based on process-related observables and (b) the ability of an autoregressive interpolation to follow signals even if not represented in the chosen set of explanatory variables. The “hybrid” estimate can be applied as ocean flux prior for atmospheric CO2 inversions covering the whole period of atmospheric CO2 data since 1957.

scholarly journals The use of forest stand age information in an atmospheric CO<sub>2</sub> inversion applied to North America

2013 ◽  
Vol 10 (8) ◽  
pp. 5335-5348 ◽  
Author(s):  
F. Deng ◽  
J. M. Chen ◽  
Y. Pan ◽  
W. Peters ◽  
R. Birdsey ◽  
...  
Keyword(s):  
North America ◽  
Carbon Flux ◽  
Age Factors ◽  
Carbon Sources ◽  
Co2 Flux ◽  
Forest Stand ◽  
Atmospheric Co2 ◽  
Stand Age ◽  
Net Ecosystem Carbon Exchange ◽  
Carbon Dioxide Co2

Abstract. Atmospheric inversions have become an important tool in quantifying carbon dioxide (CO2) sinks and sources at a variety of spatiotemporal scales, but associated large uncertainties restrain the inversion research community from reaching agreement on many important subjects. We enhanced an atmospheric inversion of the CO2 flux for North America by introducing spatially explicit information on forest stand age for US and Canada as an additional constraint, since forest carbon dynamics are closely related to time since disturbance. To use stand age information in the inversion, we converted stand age into an age factor, and included the covariances between subcontinental regions in the inversion based on the similarity of the age factors. Our inversion results show that, considering age factors, regions with recently disturbed or old forests are often nudged towards carbon sources, while regions with middle-aged productive forests are shifted towards sinks. This conforms to stand age effects observed in flux networks. At the subcontinental level, our inverted carbon fluxes agree well with continuous estimates of net ecosystem carbon exchange (NEE) upscaled from eddy covariance flux data based on MODIS data. Inverted fluxes with the age constraint exhibit stronger correlation to these upscaled NEE estimates than those inverted without the age constraint. While the carbon flux at the continental and subcontinental scales is predominantly determined by atmospheric CO2 observations, the age constraint is shown to have potential to improve the inversion of the carbon flux distribution among subcontinental regions, especially for regions lacking atmospheric CO2 observations.

scholarly journals Variasi Fluks CO2 Udara-Laut di Perairan Pesisir Pulau Bintan

2020 ◽  
Vol 5 (3) ◽  
pp. 145
Author(s):  
Afdal Afdal ◽  
Hanif Budi Prayitno ◽  
A'an Johan Wahyudi ◽  
Suci Lastrini
Keyword(s):  
Surface Water ◽  
Partial Pressure ◽  
Coastal Water ◽  
Temporal Variability ◽  
Monsoon Season ◽  
Carbon Sources ◽  
Southwest Monsoon ◽  
Spatial And Temporal Variability ◽  
Coral Reef Ecosystems ◽  
Spatio Temporal

<strong>Variation of Air-Sea CO<sub>2</sub> Fluxes in Bintan Island Coastal Water. </strong>Eastern part of Bintan coastal water plays a major role as CO<sub>2</sub> sink. However, flux and partial pressure of CO<sub>2</sub> (<em>p</em>CO<sub>2</sub>) dynamically follows spatio-temporal variability. Spatio-temporal variability of CO<sub>2</sub> flux may shows the whole condition of Bintan Island coastal water, especially in correlation with the primary production. Systematic study on variability of CO<sub>2</sub> flux from or to the watern column is essential to understand the whole conditions of Bintan Island coastal water. This study aims to understand the spatio-temporal variation of CO<sub>2</sub> fluxes in Bintan Island coastal water, and the factors influencing it. This study was conducted in the eastern part of Bintan coastal water in April and August 2014. In addition, this study was also conducted in the southern and northern parts in April 2016. CO<sub>2</sub> fluxes dynamics were calculated from <em>p</em>CO<sub>2</sub> (surface water and atmosphere), temperature, salinity, and wind speed. The result showed that almost all parts of the Bintan coastal water were carbon sources during first transition season. The largest CO<sub>2</sub> emission was observed in the northern part (4.02 ± 1.92 mmol/m<sup>2</sup>/d) followed by the southern part (2.28 ± 0.80 mmol/m<sup>2</sup>/d) and then the eastern part (0.46 ± 0.28 mmol/m<sup>2</sup>/d). The eastern part temporally turned into CO<sub>2</sub> sink in the southwest monsoon season (-0.27 ± 0.10 mmol/m<sup>2</sup>/d). Temperature was the main factor causing spatial and temporal variability of air-sea CO<sub>2</sub> fluxes in the Bintan coastal water. Spatially, the presence of seagrass and coral reef ecosystems causes the partial pressure of surface water CO<sub>2</sub> in the eastern part of waters of Bintan is much lower compared to the waters of north and south Bintan, thus emitting less CO<sub>2</sub> to the atmosphere

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