Inferring high-resolution fossil fuel CO 2 records at continental sites from combined 14 CO 2 and CO observations
TL;DR: In this article, an uncertainty estimate of a purely observational approach to derive hourly regional fossil fuel CO 2 offsets (ΔCO 2 (foss)) at continental CO 2 monitoring sites is presented.
Abstract: An uncertainty estimate of a purely observational approach to derive hourly regional fossil fuel CO 2 offsets (ΔCO 2 (foss)) at continental CO 2 monitoring sites is presented. Weekly mean 14 C-based fossil fuel CO 2 mixing ratios and corresponding regional CO offsets (ΔCO) are proposed to determine weekly mean ΔCO/ΔCO 2 (foss) ratios in order to derive hourly ΔCO 2 (foss) mixing ratios from hourly ΔCO measurements. Respective regional model estimates of CO and CO 2 (foss) are applied to test this approach and obtain root mean square errors of the correspondingly determined regional hourly fossil fuel CO 2 component. The method is further validated with campaign-based observations in Heidelberg. The uncertainty of the proposed method turns out to increase with decreasing fossil fuel CO 2 fraction ranging from about 15% up to 40% for continental Europe. Together with the uncertainty of the ΔCO/ΔCO 2 (foss) ratio, which is determined by the precision of the 14 CO 2 measurement, this method is still more accurate and precise than any model-based approach. DOI: 10.1111/j.1600-0889.2006.00244.x
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TL;DR: In this paper, high-precision atmospheric Δ 14 CO 2 records covering the last two decades are presented, and evaluated in terms of changing (radio)carbon sources and sinks, using the coarse-grid carbon cycle model GRACE.
Abstract: Global high-precision atmospheric Δ 14 CO 2 records covering the last two decades are presented, and evaluated in terms of changing (radio)carbon sources and sinks, using the coarse-grid carbon cycle model GRACE. Dedicated simulations of global trends and interhemispheric differences with respect to atmospheric CO 2 as well as δ 13 CO 2 and Δ 14 CO 2 , are shown to be in good agreement with the available observations (1940–2008). While until the 1990s the decreasing trend of Δ 14 CO 2 was governed by equilibration of the atmospheric bomb 14 C perturbation with the oceans and terrestrial biosphere, the largest perturbation today are emissions of 14 C-free fossil fuel CO 2 . This source presently depletes global atmospheric Δ 14 CO 2 by 12–14‰ yr -1 , which is partially compensated by 14 CO 2 release from the biosphere, industrial 14 C emissions and natural 14 C production. Fossil fuel emissions also drive the changing north–south gradient, showing lower Δ 14 C in the northern hemisphere only since 2002. The fossil fuel-induced north–south (and also troposphere–stratosphere) Δ 14 CO 2 gradient today also drives the tropospheric Δ 14 CO 2 seasonality through variations of air mass exchange between these atmospheric compartments. Neither the observed temporal trend nor the Δ 14 CO 2 north–south gradient may constrain global fossil fuel CO 2 emissions to better than 25%, due to large uncertainties in other components of the (radio)carbon cycle.DOI: 10.1111/j.1600-0889.2009.00446.x
282 citations
Cites methods from "Inferring high-resolution fossil fu..."
...…was primarily used to constrain stratosphere–troposphere exchange (STE, e.g. Johnston, 1989; Kjellström et al., 2000; Land et al., 2002) or assess the possibility of estimating the fossil fuel CO2 fraction by atmospheric 14CO2 measurements (Levin and Karstens, 2007; Turnbull et al., 2009)....
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TL;DR: A carbon flux model based on Network Environ Analysis (NEA) was developed and found to be better at revealing details from a mechanistic aspect, which is crucial for informed sustainable urban management.
Abstract: Cities are considered major contributors to global warming, where carbon emissions are highly embedded in the overall urban metabolism. To examine urban metabolic processes and emission trajectories we developed a carbon flux model based on Network Environ Analysis (NEA). The mutual interactions and control situation within the urban ecosystem of Vienna were examined, and the system-level properties of the city's carbon metabolism were assessed. Regulatory strategies to minimize carbon emissions were identified through the tracking of the possible pathways that affect these emission trajectories. Our findings suggest that indirect flows have a strong bearing on the mutual and control relationships between urban sectors. The metabolism of a city is considered self-mutualistic and sustainable only when the local and distal environments are embraced. Energy production and construction were found to be two factors with a major impact on carbon emissions, and whose regulation is only effective via ad-hoc pathways. In comparison with the original life-cycle tracking, the application of NEA was better at revealing details from a mechanistic aspect, which is crucial for informed sustainable urban management.
224 citations
Centre national de la recherche scientifique1, VU University Amsterdam2, Central Maine Community College3, California Institute of Technology4, University of Melbourne5, International Institute for Applied Systems Analysis6, Appalachian State University7, ETH Zurich8, Oak Ridge National Laboratory9, European Centre for Medium-Range Weather Forecasts10, University of Vienna11, University of Liège12, University of Bremen13, Earth System Research Laboratory14, CSIRO Marine and Atmospheric Research15, Boston University16, Arizona State University17, Geophysical Institute, University of Bergen18, Bjerknes Centre for Climate Research19, Max Planck Society20, Commonwealth Scientific and Industrial Research Organisation21, Food and Agriculture Organization22, Oregon State University23, Cooperative Institute for Research in Environmental Sciences24, Japan Aerospace Exploration Agency25, Alenia Aeronautica26, United States Department of Agriculture27, Peking University28, European Space Agency29, University of Sheffield30, Yale University31, National Oceanic and Atmospheric Administration32, National Ecological Observatory Network33, World Meteorological Organization34, University of Edinburgh35
TL;DR: In this article, the authors identify the current state of carbon observations, and the needs and notional requirements for a global integrated carbon observation system that can be built in the next decade, and conclude that substantial expansion of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy-relevant objectives, and attributing flux changes to underlying processes in each region.
Abstract: A globally integrated carbon observation and analysis system is needed to improve the fundamental understanding of the global carbon cycle, to improve our ability to project future changes, and to verify the effectiveness of policies aiming to reduce greenhouse gas emissions and increase carbon sequestration. Building an integrated carbon observation system requires transformational advances from the existing sparse, exploratory framework towards a dense, robust, and sustained system in all components: anthropogenic emissions, the atmosphere, the ocean, and the terrestrial biosphere. The paper is addressed to scientists, policymakers, and funding agencies who need to have a global picture of the current state of the (diverse) carbon observations. We identify the current state of carbon observations, and the needs and notional requirements for a global integrated carbon observation system that can be built in the next decade. A key conclusion is the substantial expansion of the ground-based observation networks required to reach the high spatial resolution for CO2 and CH4 fluxes, and for carbon stocks for addressing policy-relevant objectives, and attributing flux changes to underlying processes in each region. In order to establish flux and stock diagnostics over areas such as the southern oceans, tropical forests, and the Arctic, in situ observations will have to be complemented with remote-sensing measurements. Remote sensing offers the advantage of dense spatial coverage and frequent revisit. A key challenge is to bring remote-sensing measurements to a level of long-term consistency and accuracy so that they can be efficiently combined in models to reduce uncertainties, in synergy with ground-based data. Bringing tight observational constraints on fossil fuel and land use change emissions will be the biggest challenge for deployment of a policy-relevant integrated carbon observation system. This will require in situ and remotely sensed data at much higher resolution and density than currently achieved for natural fluxes, although over a small land area (cities, industrial sites, power plants), as well as the inclusion of fossil fuel CO2 proxy measurements such as radiocarbon in CO2 and carbon-fuel combustion tracers. Additionally, a policy-relevant carbon monitoring system should also provide mechanisms for reconciling regional top-down (atmosphere-based) and bottom-up (surface-based) flux estimates across the range of spatial and temporal scales relevant to mitigation policies. In addition, uncertainties for each observation data-stream should be assessed. The success of the system will rely on long-term commitments to monitoring, on improved international collaboration to fill gaps in the current observations, on sustained efforts to improve access to the different data streams and make databases interoperable, and on the calibration of each component of the system to agreed-upon international scales.
214 citations
Cites background from "Inferring high-resolution fossil fu..."
...…overcome by increasing the number of14C observations (both in terms of collection and processing) and perhaps through concerted attention to data fusion and (regularly updated) calibration of CO and NO2 as proxies of fossil fuel CO2 in each region (Levin and Karstens, 2007; Berezin et al., 2013)....
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...Measurement of proxy-tracers associated with anthropogenic emission processes: combustion tracers CO, NO2 for fossil fuel CO2, halocarbon, C2Cl4 and hydrocarbon species, and C2H6 and C3H8 for fossil fuel CH4 (e.g. Levin and Karstens, 2007; Berezin et al., 2013)....
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TL;DR: Strong seasonal variations of the fossil fuel CO2 offsets indicate a strong seasonality of emissions but also of atmospheric dilution of ground level emissions by vertical mixing.
208 citations
TL;DR: In this article, a system for constraining the spatial distribution of fossil fuel emissions of CO2 is described, based on a modified Kaya identity which expresses emissions as a product of areal population density, per capita economic activity, energy intensity of the economy, and carbon intensity of energy.
Abstract: We describe a system for constraining the spatial distribution of fossil fuel emissions of CO2. The system is based on a modified Kaya identity which expresses emissions as a product of areal population density, per capita economic activity, energy intensity of the economy, and carbon intensity of energy. We apply the methodology of data assimilation to constrain such a model with various observations, notably, the statistics of national emissions and data on the distribution of nightlights and population. We hence produce a global, annual emission field at 0.25° resolution. Our distribution of emissions is smoother than that of the population downscaling traditionally used to describe emissions. Comparison with the Vulcan inventory suggests that the assimilated product performs better than downscaling for distributions of either population or nightlights alone for describing the spatial structure of emissions over the United States. We describe the complex structure of uncertainty that arises from combining pointwise and area-integrated constraints. Uncertainties can be as high as 50% at the pixel level and are not spatially independent. We describe the use of 14CO2 measurements to further constrain national emissions. Their value is greatest over large countries with heterogeneous emissions. Generated fields may be found online (http://ffdas.org/). Copyright 2010 by the American Geophysical Union.
164 citations
References
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560 citations
"Inferring high-resolution fossil fu..." refers background in this paper
...…of fossil fuels, due to their long storage time of several hundred million years, is essentially free of 14C. Adding fossil fuel CO2 to the atmosphere, therefore, leads not only to an increase in the CO2 mixing ratio but also to a decrease in the 14C/12C ratio in atmospheric CO2 (Suess, 1955)....
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...Adding fossil fuel CO2 to the atmosphere, therefore, leads not only to an increase in the CO2 mixing ratio but also to a decrease in the 14C/12C ratio in atmospheric CO2 (Suess, 1955)....
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TL;DR: In this paper, the Radon-Tracer-Method is applied to quantify fossil fuel derived CO2 concentrations at a regional polluted site, and at a continental mountain station in south-west Germany.
Abstract: Long-term atmospheric 14CO2 observations are deployed to quantify fossil fuel derived CO2 concentrations at a regional polluted site, and at a continental mountain station in south-west Germany. Fossil fuel CO2 emission rates for the relevant catchment areas are obtained by applying the Radon-Tracer-Method. They are shown to compare well with statistical emissions inventories but reveal a larger seasonality than assumed earlier, thus contributing significantly to the observed CO2 seasonal cycle over Europe. Based on the present approach, emissions reductions on the order of 5-10% are detectable for catchment areas of several hundred kilometres radius, as anticipated within a five-years commitment period of the Kyoto Protocol. Still no significant change of fossil fuel CO2 emissions is observed at the two sites over the last 16 years.
263 citations
"Inferring high-resolution fossil fu..." refers background in this paper
...…Netherlands with fossil fuel CO2 offsets of about 3–10 ppm (Neubert, private communication, 2005); and (3) Schauinsland, a semi-remote mountain station in the Black Forest (1205 m above sea level), which experiences monthly mean fossil fuel CO2 contributions of about 1–5 ppm (Levin et al., 2003)....
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...…DOI: 10.1111/j.1600-0889.2006.00244.x measurement at a polluted sampling site, for example, in the boundary layer on the continent, we can directly calculate the regional fossil fuel CO2 surplus if the undisturbed background 14CO2 level is known (Levin et al., 2003)....
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...…populated upper Rhine valley and which shows actually observed monthly mean fossil fuel CO2 offsets relative to background air of about 5–20 ppm (Levin et al., 2003); (2) Lutjewad, a coastal site in the Netherlands with fossil fuel CO2 offsets of about 3–10 ppm (Neubert, private communication,…...
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TL;DR: In this article, the authors used the nearly ideal tracer 14CO2 to estimate the fossil fuel CO2 enhancement in boundary layer air at two sites in New England and Colorado.
Abstract: [1] We use the nearly ideal tracer 14CO2 to estimate the fossil fuel CO2 enhancement in boundary layer air at two sites in New England and Colorado Improved Δ14C measurement precision of 16–26‰ provides fossil fuel CO2 detection capability of 08–15 ppm Using the indirect tracers CO and SF6, we obtain two additional independent estimates of the fossil fuel CO2 component, and we assess the biases in these methods with respect to the 14CO2-based estimates The SF6-based estimates vary considerably from the 14CO2-based estimates, and are at times implausibly large The CO-based estimates are less variable, but show seasonally coherent biases with respect to the 14CO2 method
185 citations
"Inferring high-resolution fossil fu..." refers background in this paper
...In particular, the use of CO as a quantitative tracer of fossil fuel CO2 has been investigated recently in a number of experimental and modelling studies (Gamnitzer et al., 2006; Rivier et al., 2006; Turnbull et al., 2006)....
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01 Jan 2005
TL;DR: In this article, the authors describe the key features of the Emission Database for Global Atmospheric Research, EDGAR 3, and then the compilation of recent global trends main influencing variables and the new "Fast Track" approach to estimate recent emissions at a country-specific level.
Abstract: In 2004, JRC, MNP and MPIC have started a project to create fast (bi-)annual updates of the EDGAR global emission inventory system, based on the more detailed previous version 3.2. We first describe the key features of the Emission Database for Global Atmospheric Research, EDGAR 3, and then the compilation of recent global trends main influencing variables and the new ‘Fast Track’ approach to estimate recent emissions at a country-specific level. We present an overview of the approaches used for this ‘Fast Track’, the different source sectors and the accuracies achieved. Results will be available for 1995-2000 for various sources and greenhouse gases at regional and national scales, with a focus on the anthropogenic sources of methane.
154 citations
TL;DR: In this article, a method to quantify the relative contributions of surface sources and photochemical production of atmospheric carbon monoxide has been implemented in a three-dimensional chemical-transport model.
120 citations
"Inferring high-resolution fossil fu..." refers methods in this paper
...…atmosphere has strong diurnal and seasonal cycles, and CO also has a strong atmospheric source from oxidation of volatile organic compounds (VOCs) (Granier et al., 2000), thus complicating the use of this tracer for quantitative estimates (Potosnak et al., 1999; Gamnitzer et al., Tellus 59B…...
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