scholarly journals Reviews and syntheses: guiding the evolution of the observing system for the carbon cycle through quantitative network design

2017 ◽  
Vol 14 (20) ◽  
pp. 4755-4766 ◽  
Author(s):  
Thomas Kaminski ◽  
Peter Julian Rayner
Keyword(s):  
Carbon Cycle ◽  
Network Design ◽  
Observational Data ◽  
Data Streams ◽  
Surface Fluxes ◽  
Modelling Framework ◽  
Independent Information ◽  
The Impact ◽  
Global Carbon

Abstract. Various observational data streams have been shown to provide valuable constraints on the state and evolution of the global carbon cycle. These observations have the potential to reduce uncertainties in past, current, and predicted natural and anthropogenic surface fluxes. In particular such observations provide independent information for verification of actions as requested by the Paris Agreement. It is, however, difficult to decide which variables to sample, and how, where, and when to sample them, in order to achieve an optimal use of the observational capabilities. Quantitative network design (QND) assesses the impact of a given set of existing or hypothetical observations in a modelling framework. QND has been used to optimise in situ networks and assess the benefit to be expected from planned space missions. This paper describes recent progress and highlights aspects that are not yet sufficiently addressed. It demonstrates the advantage of an integrated QND system that can simultaneously evaluate a multitude of observational data streams and assess their complementarity and redundancy.

scholarly journals Assisting the Evolution of the Observing System for the Carbon Cycle through Quantitative Network Design

2017 ◽  
Author(s):  
Thomas Kaminski ◽  
Peter Julian Rayner
Keyword(s):  
Carbon Cycle ◽  
Network Design ◽  
Observational Data ◽  
Data Streams ◽  
Recent Progress ◽  
Global Carbon Cycle ◽  
Modelling Framework ◽  
The Impact ◽  
Global Carbon

Abstract. Various observational data streams have been shown to provide valuable constraints on the state and evolution of the global carbon cycle. It is, however, difficult to decide which variables to sample how, where and when in order to achieve an optimal use of the observational capabilities. Quantitative Network Design (QND) assesses the impact of a given set of existing or hypothetical observations in a modelling framework. QND has been used to optimise in situ networks and assess the benefit from planned space missions. This paper describes recent progress and points at aspects that are not yet sufficiently addressed. It demonstrates the advantage of an integrated QND system that can simultaneously evaluate a multitude of observational data streams and assess their complementarity and redundancy.

Basalt weathering laws and the impact of basalt weathering on the global carbon cycle

2003 ◽  
Vol 202 (3-4) ◽  
pp. 257-273 ◽  
Author(s):  
Céline Dessert ◽  
Bernard Dupré ◽  
Jérôme Gaillardet ◽  
Louis M. François ◽  
Claude J. Allègre
Keyword(s):  
Carbon Cycle ◽  
Global Carbon Cycle ◽  
Basalt Weathering ◽  
The Impact ◽  
Global Carbon

scholarly journals Organic Geochemical Characteristics of the Upper Cretaceous Qingshankou Formation Oil Shales in the Fuyu Oilfield, Songliao Basin, China: Implications for Oil-Generation Potential and Depositional Environment

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4778 ◽  
Author(s):  
Wentong He ◽  
Youhong Sun ◽  
Wei Guo ◽  
Xuanlong Shan ◽  
Siyuan Su ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Cycle ◽  
Depositional Environment ◽  
Global Carbon Cycle ◽  
Songliao Basin ◽  
Oil Generation ◽  
Oil Shales ◽  
Extractable Organic Matter ◽  
The Impact ◽  
Global Carbon

The Cretaceous Era has always been a focus of geologic and palaeoenvironmental studies. Previous researchers believed that the impact of the global carbon cycle represents significant short-term global biogeochemical fluctuations, leading to the formation of a large number of organic rich sediments in the marine environment. During the Turonian, a large number of organic-rich oil shales were deposited in the lakes of the Songliao Basin in the Qingshankou Formation. How the depositional environment affected the formation of oil shales in continental lakes and the characteristics of these oil shales remain controversial. In this paper, through sampling of Qingshankou Formation strata, various testing methods are used to provide a variety of new data to study the characteristics of oil shales and palaeoenvironment evolution history in the Songliao Basin. The research of the sediments in the Qingshankou Formation in the Fuyu oilfield, Songliao Basin, via result analysis revealed that the oil shales possess an excellent oil-generation potential with moderate-high total organic carbon (TOC) levels (0.58–9.43%), high hydrogen index (HI) values (265–959 mg hydrocarbons (HC)/g TOC), high extractable organic matter (EOM) levels (2.50–6.96 mg/g TOC) and high hydrocarbon fractions (48–89%). The sources of the organic matter were mainly zooplankton, red algae and higher plants (including marine organisms). The aqueous palaeoenvironment of the Qingshankou Formation was a saline water environment with a high sulfate concentration, which promoted an increase in nutrients and stratification of the water density in the lake basin. Oxygen consumption in the bottom water layer promoted the accumulation and burial of high-abundance organic matter, thus forming the high-quality oil shales in the Qingshankou Formation. The global carbon cycle, warm-humid palaeoclimate, dynamic local biogeochemical cycling and relative passive tectonism were the most likely reasons for the TOC increase and negative δ13Corg deviation.

scholarly journals Consistent assimilation of multiple data streams in a carbon cycle data assimilation system

2016 ◽  
Author(s):  
Natasha MacBean ◽  
Philippe Peylin ◽  
Frédéric Chevallier ◽  
Marko Scholze ◽  
Gregor Schürmann
Keyword(s):  
Data Assimilation ◽  
Carbon Cycle ◽  
Data Streams ◽  
Land Surface ◽  
Inversion Algorithm ◽  
Spatial And Temporal Scales ◽  
Multiple Data ◽  
Combining Data ◽  
Multiple Data Streams ◽  
The Impact

Abstract. Data assimilation methods provide a rigorous statistical framework for constraining the parametric uncertainty of land surface models (LSMs), with the aim of improving our predictive capability as well as identifying areas in which the models need improvement. The increase in the number of available datasets in recent years allows us to address different aspects of the model at a variety of spatial and temporal scales. However, combining data streams in a DA system is not a trivial task. In this study we highlight some of the challenges surrounding multiple data stream assimilation, with a particular focus on the carbon cycle component of LSMs. We examine the impact of biases and inconsistencies between the observations and the model (resulting in non Gaussian error distributions) and the impact of non-linearity in model dynamics. In addition we explore the differences between performing a simultaneous assimilation (in which all data streams are included in one optimisation) and a step-wise approach (in which each data steam is assimilated sequentially), given the assumptions inherent to the inversion algorithm chosen for this study. We demonstrate some of these issues by assimilating synthetic observations into two simple models: the first a simplified version of the carbon cycle processes represented in many LSMs, and the second a non-linear toy model. We further discuss these experimental results in the context of recent studies in the carbon cycle data assimilation literature, and finally we provide some perspectives and advice to other land surface modellers wishing to use multiple data streams to constrain their models.

scholarly journals The impact of different external sources of iron on the global carbon cycle

2014 ◽  
Vol 41 (3) ◽  
pp. 920-926 ◽  
Author(s):  
Alessandro Tagliabue ◽  
Olivier Aumont ◽  
Laurent Bopp
Keyword(s):  
Carbon Cycle ◽  
Global Carbon Cycle ◽  
External Sources ◽  
The Impact ◽  
Global Carbon

scholarly journals EUROSPEC: at the interface between remote sensing and ecosystem CO<sub>2</sub> flux measurements in Europe

2015 ◽  
Vol 12 (15) ◽  
pp. 13069-13121 ◽  
Author(s):  
A. Porcar-Castell ◽  
A. Mac Arthur ◽  
M. Rossini ◽  
L. Eklundh ◽  
J. Pacheco-Labrador ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Carbon Cycle ◽  
Temporal Dynamics ◽  
Remote Sensing Data ◽  
Terrestrial Ecosystems ◽  
Global Carbon Cycle ◽  
Spectral Measurements ◽  
Cost Action ◽  
Global Carbon

Abstract. Resolving the spatial and temporal dynamics of gross primary productivity (GPP) of terrestrial ecosystems across different scales remains a challenge. Remote sensing is regarded as the solution to upscale point observations conducted at the ecosystem level, using the eddy covariance (EC) technique, to the landscape and global levels. In addition to traditional vegetation indices, the photochemical reflectance index (PRI) and the emission of solar-induced chlorophyll fluorescence (SIF), now measurable from space, provide a new range of opportunities to monitor the global carbon cycle using remote sensing. However, the scale mismatch between EC observations and the much coarser satellite-derived data complicates the integration of the two sources of data. The solution is to establish a network of in situ spectral measurements that can act as bridge between EC measurements and remote sensing data. In situ spectral measurements have been already conducted for many years at EC sites, but using variable instrumentation, setups, and measurement standards. In Europe in particular, in situ spectral measurements remain highly heterogeneous. The goal of EUROSPEC Cost Action ES0930 was to promote the development of common measuring protocols and new instruments towards establishing best practices and standardization of in situ spectral measurements. In this review we describe the background and main tradeoffs of in situ spectral measurements, review the main results of EUROSPEC Cost Action, and discuss the future challenges and opportunities of in situ spectral measurements for improved estimation of local and global carbon cycle.

scholarly journals The Impact of Agricultural Soil Erosion on the Global Carbon Cycle

Science ◽  
2007 ◽  
Vol 318 (5850) ◽  
pp. 626-629 ◽  
Author(s):  
K. Van Oost ◽  
T. A. Quine ◽  
G. Govers ◽  
S. De Gryze ◽  
J. Six ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Carbon Cycle ◽  
Agricultural Soil ◽  
Large Scale ◽  
Carbon Sink ◽  
Global Carbon Cycle ◽  
Agricultural Landscapes ◽  
Carbon Equivalent ◽  
The Impact ◽  
Global Carbon

Agricultural soil erosion is thought to perturb the global carbon cycle, but estimates of its effect range from a source of 1 petagram per year–1to a sink of the same magnitude. By using caesium-137 and carbon inventory measurements from a large-scale survey, we found consistent evidence for an erosion-induced sink of atmospheric carbon equivalent to approximately 26% of the carbon transported by erosion. Based on this relationship, we estimated a global carbon sink of 0.12 (range 0.06 to 0.27) petagrams of carbon per year–1resulting from erosion in the world's agricultural landscapes. Our analysis directly challenges the view that agricultural erosion represents an important source or sink for atmospheric CO2.

scholarly journals The effect of assimilating satellite-derived soil moisture data in SiBCASA on simulated carbon fluxes in Boreal Eurasia

2016 ◽  
Vol 20 (2) ◽  
pp. 605-624 ◽  
Author(s):  
M. K. van der Molen ◽  
R. A. M. de Jeu ◽  
W. Wagner ◽  
I. R. van der Velde ◽  
P. Kolari ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Carbon Cycle ◽  
Carbon Fluxes ◽  
Vegetation Model ◽  
Annual Variations ◽  
Data Usage ◽  
Order Of Magnitude ◽  
Active Data ◽  
Global Carbon

Abstract. Boreal Eurasia is a region where the interaction between droughts and the carbon cycle may have significant impacts on the global carbon cycle. Yet the region is extremely data sparse with respect to meteorology, soil moisture, and carbon fluxes as compared to e.g. Europe. To better constrain our vegetation model SiBCASA, we increase data usage by assimilating two streams of satellite-derived soil moisture. We study whether the assimilation improved SiBCASA's soil moisture and its effect on the simulated carbon fluxes. By comparing to unique in situ soil moisture observations, we show that the passive microwave soil moisture product did not improve the soil moisture simulated by SiBCASA, but the active data seem promising in some aspects. The match between SiBCASA and ASCAT soil moisture is best in the summer months over low vegetation. Nevertheless, ASCAT failed to detect the major droughts occurring between 2007 and 2013. The performance of ASCAT soil moisture seems to be particularly sensitive to ponding, rather than to biomass. The effect on the simulated carbon fluxes is large, 5–10 % on annual GPP and TER, tens of percent on local NEE, and 2 % on area-integrated NEE, which is the same order of magnitude as the inter-annual variations. Consequently, this study shows that assimilation of satellite-derived soil moisture has potentially large impacts, while at the same time further research is needed to understand under which conditions the satellite-derived soil moisture improves the simulated soil moisture.

scholarly journals Goldilocks at the dawn of complex life: mountains might have damaged Ediacaran–Cambrian ecosystems and prompted an early Cambrian greenhouse world

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabricio Caxito ◽  
Cristiano Lana ◽  
Robert Frei ◽  
Gabriel J. Uhlein ◽  
Alcides N. Sial ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Global Carbon Cycle ◽  
Optimal Level ◽  
Basin Evolution ◽  
Early Cambrian ◽  
Nutrient Input ◽  
Late Neoproterozoic ◽  
Global Carbon ◽  
Level Effect

AbstractWe combine U–Pb in-situ carbonate dating, elemental and isotope constraints to calibrate the synergy of integrated mountain-basin evolution in western Gondwana. We show that deposition of the Bambuí Group coincides with closure of the Goiás-Pharusian (630–600 Ma) and Adamastor (585–530 Ma) oceans. Metazoans thrived for a brief moment of balanced redox and nutrient conditions. This was followed, however, by closure of the Clymene ocean (540–500 Ma), eventually landlocking the basin. This hindered seawater renewal and led to uncontrolled nutrient input, shallowing of the redoxcline and anoxic incursions, fueling positive productivity feedbacks and preventing the development of typical Ediacaran–Cambrian ecosystems. Thus, mountains provide the conditions, such as oxygen and nutrients, but may also preclude life development if basins become too restricted, characterizing a Goldilocks or optimal level effect. During the late Neoproterozoic-Cambrian fan-like transition from Rodinia to Gondwana, the newborn marginal basins of Laurentia, Baltica and Siberia remained open to the global sea, while intracontinental basins of Gondwana became progressively landlocked. The extent to which basin restriction might have affected the global carbon cycle and climate, e.g. through the input of gases such as methane that could eventually have collaborated to an early Cambrian greenhouse world, needs to be further considered.

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