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Peter Landschützer - One of the best experts on this subject based on the ideXlab platform.
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decadal trends in the ocean Carbon Sink
Proceedings of the National Academy of Sciences of the United States of America, 2019Co-Authors: Tim Devries, Peter Landschützer, Corinne Le Quere, Oliver Andrews, Sarah Berthet, Judith Hauck, Tatiana Ilyina, A Lenton, Ivan D LimaAbstract:Measurements show large decadal variability in the rate of [Formula: see text] accumulation in the atmosphere that is not driven by [Formula: see text] emissions. The decade of the 1990s experienced enhanced Carbon accumulation in the atmosphere relative to emissions, while in the 2000s, the atmospheric growth rate slowed, even though emissions grew rapidly. These variations are driven by natural sources and Sinks of [Formula: see text] due to the ocean and the terrestrial biosphere. In this study, we compare three independent methods for estimating oceanic [Formula: see text] uptake and find that the ocean Carbon Sink could be responsible for up to 40% of the observed decadal variability in atmospheric [Formula: see text] accumulation. Data-based estimates of the ocean Carbon Sink from [Formula: see text] mapping methods and decadal ocean inverse models generally agree on the magnitude and sign of decadal variability in the ocean [Formula: see text] Sink at both global and regional scales. Simulations with ocean biogeochemical models confirm that climate variability drove the observed decadal trends in ocean [Formula: see text] uptake, but also demonstrate that the sensitivity of ocean [Formula: see text] uptake to climate variability may be too weak in models. Furthermore, all estimates point toward coherent decadal variability in the oceanic and terrestrial [Formula: see text] Sinks, and this variability is not well-matched by current global vegetation models. Reconciling these differences will help to constrain the sensitivity of oceanic and terrestrial [Formula: see text] uptake to climate variability and lead to improved climate projections and decadal climate predictions.
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regional wind variability modulates the southern ocean Carbon Sink
Scientific Reports, 2019Co-Authors: Lydia Keppler, Peter LandschützerAbstract:The Southern Ocean south of 35°S accounts for approximately half of the annual oceanic Carbon uptake, thereby substantially mitigating the effects of anthropogenic Carbon dioxide (CO2) emissions. The intensity of this important Carbon Sink varies considerably on inter-annual to decadal timescales. However, the drivers of this variability are still debated, challenging our ability to accurately predict the future role of the Southern Ocean in absorbing atmospheric Carbon. Analysing mapped sea-air CO2 fluxes, estimated from upscaled surface ocean CO2 measurements, we find that the overall Southern Ocean Carbon Sink has weakened since ~2011, reversing the trend of the reinvigoration period of the 2000s. Although we find significant regional positive and negative responses of the Southern Ocean Carbon uptake to changes in the Southern Annular Mode (SAM) over the past 35 years, the net effect of the SAM on the Southern Ocean Carbon Sink variability is approximately zero, due to the opposing effects of enhanced outgassing in upwelling regions and enhanced Carbon uptake elsewhere. Instead, regional shifts in sea level pressure, linked to zonal wavenumber 3 (ZW3) and related changes in surface winds substantially contribute to the inter-annual to decadal variability of the Southern Ocean Carbon Sink.
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the variable southern ocean Carbon Sink
Annual Review of Marine Science, 2019Co-Authors: Nicolas Gruber, Peter Landschützer, Nicole S LovenduskiAbstract:The CO2 uptake by the Southern Ocean (<35°S) varies substantially on all timescales and is a major determinant of the variations of the global ocean Carbon Sink. Particularly strong are the decadal...
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The reinvigoration of the Southern Ocean Carbon Sink
Science, 2015Co-Authors: Peter Landschützer, Nicolas Gruber, F. Alexander Haumann, Christian Rödenbeck, Dorothee C. E. Bakker, Steven Van Heuven, Mario Hoppema, Nicolas Metzl, Colm Sweeney, Taro TakahashiAbstract:Several studies have suggested that the Carbon Sink in the Southern Ocean—the ocean’s strongest region for the uptake of anthropogenic CO2 —has weakened in recent decades. We demonstrated, on the basis of multidecadal analyses of surface ocean CO2 observations, that this weakening trend stopped around 2002, and by 2012, the Southern Ocean had regained its expected strength based on the growth of atmospheric CO2. All three Southern Ocean sectors have contributed to this reinvigoration of the Carbon Sink, yet differences in the processes between sectors exist, related to a tendency toward a zonally more asymmetric atmospheric circulation. The large decadal variations in the Southern Ocean Carbon Sink suggest a rather dynamic ocean Carbon cycle that varies more in time than previously recognized.
Nicole S Lovenduski - One of the best experts on this subject based on the ideXlab platform.
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the variable southern ocean Carbon Sink
Annual Review of Marine Science, 2019Co-Authors: Nicolas Gruber, Peter Landschützer, Nicole S LovenduskiAbstract:The CO2 uptake by the Southern Ocean (<35°S) varies substantially on all timescales and is a major determinant of the variations of the global ocean Carbon Sink. Particularly strong are the decadal...
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Timescales for detection of trends in the ocean Carbon Sink
Nature, 2016Co-Authors: Galen A. Mckinley, Darren Pilcher, Amanda R. Fay, Keith Lindsay, Matthew C. Long, Nicole S LovenduskiAbstract:The ocean has absorbed 41 per cent of all anthropogenic Carbon emitted as a result of fossil fuel burning and cement manufacture. The magnitude and the large-scale distribution of the ocean Carbon Sink is well quantified for recent decades. In contrast, temporal changes in the oceanic Carbon Sink remain poorly understood. It has proved difficult to distinguish between air-to-sea Carbon flux trends that are due to anthropogenic climate change and those due to internal climate variability. Here we use a modelling approach that allows for this separation, revealing how the ocean Carbon Sink may be expected to change throughout this century in different oceanic regions. Our findings suggest that, owing to large internal climate variability, it is unlikely that changes in the rate of anthropogenic Carbon uptake can be directly observed in most oceanic regions at present, but that this may become possible between 2020 and 2050 in some regions.
Nicolas Gruber - One of the best experts on this subject based on the ideXlab platform.
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the variable southern ocean Carbon Sink
Annual Review of Marine Science, 2019Co-Authors: Nicolas Gruber, Peter Landschützer, Nicole S LovenduskiAbstract:The CO2 uptake by the Southern Ocean (<35°S) varies substantially on all timescales and is a major determinant of the variations of the global ocean Carbon Sink. Particularly strong are the decadal...
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The reinvigoration of the Southern Ocean Carbon Sink
Science, 2015Co-Authors: Peter Landschützer, Nicolas Gruber, F. Alexander Haumann, Christian Rödenbeck, Dorothee C. E. Bakker, Steven Van Heuven, Mario Hoppema, Nicolas Metzl, Colm Sweeney, Taro TakahashiAbstract:Several studies have suggested that the Carbon Sink in the Southern Ocean—the ocean’s strongest region for the uptake of anthropogenic CO2 —has weakened in recent decades. We demonstrated, on the basis of multidecadal analyses of surface ocean CO2 observations, that this weakening trend stopped around 2002, and by 2012, the Southern Ocean had regained its expected strength based on the growth of atmospheric CO2. All three Southern Ocean sectors have contributed to this reinvigoration of the Carbon Sink, yet differences in the processes between sectors exist, related to a tendency toward a zonally more asymmetric atmospheric circulation. The large decadal variations in the Southern Ocean Carbon Sink suggest a rather dynamic ocean Carbon cycle that varies more in time than previously recognized.
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interannual variability in the north atlantic ocean Carbon Sink
Science, 2002Co-Authors: Nicolas Gruber, Charles D Keeling, Nicholas R BatesAbstract:The North Atlantic is believed to represent the largest ocean Sink for atmospheric Carbon dioxide in the Northern Hemisphere, yet little is known about its temporal variability. We report an 18-year time series of upper-ocean inorganic Carbon observations from the northwestern subtropical North Atlantic near Bermuda that indicates substantial variability in this Sink. We deduce that the Carbon variability at this site is largely driven by variations in winter mixed-layer depths and by sea surface temperature anomalies. Because these variations tend to occur in a basinwide coordinated pattern associated with the North Atlantic Oscillation, it is plausible that the entire North Atlantic Ocean may vary in concert, resulting in a variability of the strength of the North Atlantic Carbon Sink of about ±0.3 petagrams of Carbon per year (1 petagram = 1015grams) or nearly ±50%. This extrapolation is supported by basin-wide estimates from atmospheric Carbon dioxide inversions.
Lydia Keppler - One of the best experts on this subject based on the ideXlab platform.
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regional wind variability modulates the southern ocean Carbon Sink
Scientific Reports, 2019Co-Authors: Lydia Keppler, Peter LandschützerAbstract:The Southern Ocean south of 35°S accounts for approximately half of the annual oceanic Carbon uptake, thereby substantially mitigating the effects of anthropogenic Carbon dioxide (CO2) emissions. The intensity of this important Carbon Sink varies considerably on inter-annual to decadal timescales. However, the drivers of this variability are still debated, challenging our ability to accurately predict the future role of the Southern Ocean in absorbing atmospheric Carbon. Analysing mapped sea-air CO2 fluxes, estimated from upscaled surface ocean CO2 measurements, we find that the overall Southern Ocean Carbon Sink has weakened since ~2011, reversing the trend of the reinvigoration period of the 2000s. Although we find significant regional positive and negative responses of the Southern Ocean Carbon uptake to changes in the Southern Annular Mode (SAM) over the past 35 years, the net effect of the SAM on the Southern Ocean Carbon Sink variability is approximately zero, due to the opposing effects of enhanced outgassing in upwelling regions and enhanced Carbon uptake elsewhere. Instead, regional shifts in sea level pressure, linked to zonal wavenumber 3 (ZW3) and related changes in surface winds substantially contribute to the inter-annual to decadal variability of the Southern Ocean Carbon Sink.
Dale H. Vitt - One of the best experts on this subject based on the ideXlab platform.
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current disturbance and the diminishing peatland Carbon Sink
Geophysical Research Letters, 2002Co-Authors: Merritt R. Turetsky, Kelman R Wieder, Lawrence A. Halsey, Dale H. VittAbstract:[1] Cumulative impacts of disturbances on peatland Carbon must be understood to predict future soil Carbon stocks, yet the vulnerability and response of peatlands to disturbance have been neglected. We provide the first regional-scale assessment of peatland Carbon storage across 1.7 million km2 of western boreal land. We estimate that disturbances, mainly fire, release approximately 6460 ± 930 GgCyr−1 to the atmosphere. Concurrently, disturbances reduce Carbon uptake in continental peatlands by 85% compared to a no-disturbance scenario. A 17% increase in the area of peatland burned annually and the intensity of organic matter combustion would convert these peatlands into a regional net source of Carbon to the atmosphere. Peatlands widely are considered to represent a northern Carbon Sink, however, we suggest reevaluation of this paradigm for continental boreal regions.