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Ice core records of the major atmospheric greenhouse gases (CO2, CH4, N2O) and their isotopologues covering recent centuries provide evidence of biogeochemical variations during the Late Holocene and pre-industrial periods and over the transition to the industrial period. These records come from a number of ice core and firn air sites and have been measured in several laboratories around the world and show common features but also unresolved differences. Here we present revised records, including new measurements, performed at the CSIRO Ice Core Extraction LABoratory (ICELAB) on air samples from ice obtained at the high-accumulation site of Law Dome (East Antarctica). We are motivated by the increasing use of the records by the scientific community and by recent data-handling developments at CSIRO ICELAB. A number of cores and firn air samples have been collected at Law Dome to provide high-resolution records overlapping recent, direct atmospheric observations. The records have been updated through a dynamic link to the calibration scales used in the Global Atmospheric Sampling LABoratory (GASLAB) at CSIRO, which are periodically revised with information from the latest calibration experiments. The gas-age scales have been revised based on new ice-age scales and the information derived from a new version of the CSIRO firn diffusion model. Additionally, the records have been revised with new, rule-based selection criteria and updated corrections for biases associated with the extraction procedure and the effects of gravity and diffusion in the firn. All measurements carried out in ICELAB–GASLAB over the last 25 years are now managed through a database (the ICElab dataBASE or ICEBASE), which provides consistent data management, automatic corrections and selection of measurements, and a web-based user interface for data extraction. We present the new records, discuss their strengths and limitations, and summarise their main features. The records reveal changes in the carbon cycle and atmospheric chemistry over the last 2 millennia, including the major changes of the anthropogenic era and the smaller, mainly natural variations beforehand. They provide the historical data to calibrate and test the next inter-comparison of models used to predict future climate change (Coupled Model Inter-comparison Project – phase 6, CMIP6). The datasets described in this paper, including spline fits, are available at https://doi.org/10.25919/5bfe29ff807fb (Rubino et al., 2019).

Rationale Nitrate pollution represents one of the most important issues for ground and surface water quality and source identification is essential for developing effective mitigation practices. Nitrate isotopic fingerprinting can be utilized to identify the sources of nitrate pollution in aquifers. However, it is crucial to assess the performances (precision and accuracy) of the analytical procedure applied to measure the δ15 N and δ18 O values of nitrates from field samples to correctly apply this tool. Methods Nitrates were extracted from a large number of KNO3 samples using the AgNO3 method, and the δ15 N and δ18 O values of these nitrate extracts were measured by isotope ratio mass spectrometry. The availability of this dataset, comprising 693 unprocessed quality control (QC) KNO3 samples and 618 processed samples, allowed us to rigorously quantify the performance of the procedures employed. A salt doping experiment was also performed from which the effects of contaminants on the performance of the method could be ascertained. Results The overall instrumental reproducibility for the analysis of unprocessed QC samples was 0.5‰ and 2‰ for δ15 N and δ18 O values, respectively, and a strict dependence on signal amplitude was observed. No isotope fractionation was reported for reference samples that were processed according to the "identical treatment" principle (ITP) but normalized by unprocessed reference materials. A significant increase in the standard deviation (SD) was, however, observed compared with that for unprocessed samples. The SD of the processed QC samples allowed us to quantify the reproducibility of the entire procedure as 0.6‰ and 1.0‰ for δ15 N and δ18 O values, respectively. This was comparable with the system reproducibility when normalization using processed reference materials was applied according to the ITP. Conclusions Normalization with processed standards is essential to achieve high-precision measurements of the δ15 N and δ18 O values of nitrates extracted from unknown samples. This procedure allowed good accuracy to be guaranteed, and precision levels comparable with the observed instrumental performance to be achieved. A salt doping experiment showed a significant influence of the SO4 2- content on the δ15 N values.

Nitrate pollution represents one of the most important issues for ground and surface water quality and source identification is essential for developing effective mitigation practices. Nitrate isotopic fingerprinting can be utilized to identify the sources of nitrate pollution in aquifers. However, it is crucial to assess the performances (precision and accuracy) of the analytical procedure applied to measure the δNitrates were extracted from a large number of KNOThe overall instrumental reproducibility for the analysis of unprocessed QC samples was 0.5‰ and 2‰ for δNormalization with processed standards is essential to achieve high-precision measurements of the δ

The Southern Ocean occupies 14% of the Earth’s surface and plays a fundamental role in the global carbon cycle and climate. It provides a direct connection to the deep ocean carbon reservoir through biogeochemical processes that include surface primary productivity, remineralization at depth and the upwelling of carbon-rich water masses. However, the role of these different processes in modulating past and future air–sea carbon flux remains poorly understood. A key period in this regard is the Antarctic Cold Reversal (ACR, 14.6–12.7 kyr bp), when mid- to high-latitude Southern Hemisphere cooling coincided with a sustained plateau in the global deglacial increase in atmospheric CO2. Here we reconstruct high-latitude Southern Ocean surface productivity from marine-derived aerosols captured in a highly resolved horizontal ice core. Our multiproxy reconstruction reveals a sustained signal of enhanced marine productivity across the ACR. Transient climate modelling indicates this period coincided with maximum seasonal variability in sea-ice extent, implying that sea-ice biological feedbacks enhanced CO2 sequestration and created a substantial regional marine carbon sink, which contributed to the plateau in CO2 during the ACR. Our results highlight the role Antarctic sea ice plays in controlling global CO2, and demonstrate the need to incorporate such feedbacks into climate–carbon models.

Significance Fifty years ago, it was speculated that the marine-based West Antarctic Ice Sheet is vulnerable to warming and may have melted in the past. Testing this hypothesis has proved challenging due to the difficulty of developing in situ records of ice sheet and environmental change spanning warm periods. We present a multiproxy record that implies loss of the West Antarctic Ice Sheet during the Last Interglacial (129,000 to 116,000 y ago), associated with ocean warming and the release of greenhouse gas methane from marine sediments. Our ice sheet modeling predicts that Antarctica may have contributed several meters to global sea level at this time, suggesting that this ice sheet lies close to a “tipping point” under projected warming., The future response of the Antarctic ice sheet to rising temperatures remains highly uncertain. A useful period for assessing the sensitivity of Antarctica to warming is the Last Interglacial (LIG) (129 to 116 ky), which experienced warmer polar temperatures and higher global mean sea level (GMSL) (+6 to 9 m) relative to present day. LIG sea level cannot be fully explained by Greenland Ice Sheet melt (∼2 m), ocean thermal expansion, and melting mountain glaciers (∼1 m), suggesting substantial Antarctic mass loss was initiated by warming of Southern Ocean waters, resulting from a weakening Atlantic meridional overturning circulation in response to North Atlantic surface freshening. Here, we report a blue-ice record of ice sheet and environmental change from the Weddell Sea Embayment at the periphery of the marine-based West Antarctic Ice Sheet (WAIS), which is underlain by major methane hydrate reserves. Constrained by a widespread volcanic horizon and supported by ancient microbial DNA analyses, we provide evidence for substantial mass loss across the Weddell Sea Embayment during the LIG, most likely driven by ocean warming and associated with destabilization of subglacial hydrates. Ice sheet modeling supports this interpretation and suggests that millennial-scale warming of the Southern Ocean could have triggered a multimeter rise in global sea levels. Our data indicate that Antarctica is highly vulnerable to projected increases in ocean temperatures and may drive ice–climate feedbacks that further amplify warming.

The isotopic composition of carbon (Δ14C and δ13C) in atmospheric CO2 and in oceanic and terrestrial carbon reservoirs is influenced by anthropogenic emissions and by natural carbon exchanges, which can respond to and drive changes in climate. Simulations of 14C and 13C in the ocean and terrestrial components of Earth System Models (ESMs) present opportunities for model evaluation and for investigation of carbon cycling, including anthropogenic CO2 emissions and uptake. The use of carbon isotopes in novel evaluation of the ESMs' component ocean and terrestrial biosphere models and in new analyses of historical changes may improve predictions of future changes in the carbon cycle and climate system. We compile existing data to produce records of Δ14C and δ13C in atmospheric CO2 for the historical period 1850–2015. The primary motivation for this compilation is to provide the atmospheric boundary condition for historical simulations in the Coupled Model Intercomparison Project 6 (CMIP6) for models simulating carbon isotopes in their ocean or terrestrial biosphere models. The data may also be useful for other carbon cycle modelling activities.

Many users of international arbitration, particularly in-house counsel, have repeatedly expressed concern about the lack of adequate information on arbitrators, resulting in arbitrator selection based on a vague and general reputation often informed by word of mouth or anecdotal information. Arbitral institutions and arbitration circles cannot remain indifferent to this need. A first step to deal with this issue is the disclosure by arbitrators of the information contained in the arbitrator ’ s pledge launched by the European Court of Arbitration; another step is the issuance of an official acknowledgement as a ‘ certified arbitrator ’ by arbitral institutions, and eventually the requirement that certified arbitrators abide by a universal code of ethics.

Palaeoatmospheric records of carbon dioxide and its stable carbon isotope composition (δ13C) obtained from polar ice cores provide important constraints on the natural variability of the carbon cycle. However, the measurements are both analytically challenging and time-consuming; thus only data exist from a limited number of sampling sites and time periods. Additional analytical resources with high analytical precision and throughput are thus desirable to extend the existing datasets. Moreover, consistent measurements derived by independent laboratories and a variety of analytical systems help to further increase confidence in the global CO2 palaeo-reconstructions. Here, we describe our new set-up for simultaneous measurements of atmospheric CO2 mixing ratios and atmospheric δ13C and δ18O-CO2 in air extracted from ice core samples. The centrepiece of the system is a newly designed needle cracker for the mechanical release of air entrapped in ice core samples of 8–13 g operated at −45 °C. The small sample size allows for high resolution and replicate sampling schemes. In our method, CO2 is cryogenically and chromatographically separated from the bulk air and its isotopic composition subsequently determined by continuous flow isotope ratio mass spectrometry (IRMS). In combination with thermal conductivity measurement of the bulk air, the CO2 mixing ratio is calculated. The analytical precision determined from standard air sample measurements over ice is ±1.9 ppm for CO2 and ±0.09 ‰ for δ13C. In a laboratory intercomparison study with CSIRO (Aspendale, Australia), good agreement between CO2 and δ13C results is found for Law Dome ice core samples. Replicate analysis of these samples resulted in a pooled standard deviation of 2.0 ppm for CO2 and 0.11 ‰ for δ13C. These numbers are good, though they are rather conservative estimates of the overall analytical precision achieved for single ice sample measurements. Facilitated by the small sample requirement, replicate measurements are feasible, allowing the method precision to be improved potentially. Further, new analytical approaches are introduced for the accurate correction of the procedural blank and for a consistent detection of measurement outliers, which is based on δ18O-CO2 and the exchange of oxygen between CO2 and the surrounding ice (H2O).

Low atmospheric carbon dioxide (CO 2) concentration during the Little Ice Age has been used to derive the global carbon cycle sensitivity to temperature. Recent evidence confirms earlier indications that the low CO 2 was caused by increased terrestrial carbon storage. It remains unknown whether the terrestrial biosphere responded to temperature variations, or there was vegetation re-growth on abandoned farmland. Here we present a global numerical simulation of atmospheric carbonyl sulfide concentrations in the pre-industrial period. Carbonyl sulfide concentration is linked to changes in gross primary production and shows a positive anomaly during the Little Ice Age. We show that a decrease in gross primary production and a larger decrease in ecosystem respiration is the most likely explanation for the decrease in atmospheric CO 2 and increase in atmospheric carbonyl sulfide concentrations. Therefore, temperature change, not vegetation re-growth, was the main cause of the increased terrestrial carbon storage. We address the inconsistency between ice-core CO 2 records from different sites measuring CO 2 and Í 13 CO 2 in ice from Dronning Maud Land (Antarctica). Our interpretation allows us to derive the temperature sensitivity of pre-industrial CO 2 fluxes for the terrestrial biosphere (I 3 L = â '10 to â '90 Pg C K â '1), implying a positive climate feedback and providing a benchmark to reduce model uncertainties.

Ice core records of the major atmospheric greenhouse gases (CO2, CH4, N2O) and their isotopologues covering recent centuries provide evidence of biogeochemical variations during the Late-Holocene and Pre-Industrial Periods and over the transition to the Industrial Period. These records come from a number of ice core and firn air sites, and have been measured in several laboratories around the world and show common features, but also unresolved differences. Here we present revised records, including new measurements, performed at the CSIRO Ice Core Extraction LABoratory (ICELAB) on air samples from ice obtained at the high accumulation site of Law Dome (East Antarctica). We are motivated by the increasing use of the records by the scientific community and by recent data-handling developments at CSIRO-ICELAB. A number of cores and firn air samples have been collected at Law Dome to provide high resolution records overlapping recent, direct atmospheric observations. The records have been updated through a dynamic link to the calibration scales used in the Global Atmospheric Sampling LABoratory (GASLAB) at CSIRO, which are periodically revised with information from the latest calibration experiments. The gas-age scales have been revised based on new ice-age scales, and the information derived from a new version of the CSIRO firn diffusion model. Additionally, the records have been revised with new, rule-based selection criteria and updated corrections for biases associated with the extraction procedure, and the effects of gravity and diffusion in the firn. All measurements carried out in ICELAB-GASLAB over the last 25 years are now managed through a database (the ICElab dataBASE or ICEBASE) which provides consistent data management, automatic corrections and selection of measurements, and a web-based user interface for data extraction. We present the new records, discuss their strengths and limitations and summarise their main features. The records reveal changes in the carbon cycle and atmospheric chemistry over the last two millennia, including the major changes of the anthropogenic era and the smaller, mainly natural variations beforehand. They provide the historical data to calibrate and test the next inter-comparison of models used to predict future climate change (Coupled Model Inter-comparison Project - phase 6, CMIP6). The datasets described in this paper, including spline fits, are available at https://doi.org/10.25919/5bfe29ff807fb (Rubino et al., 2018).

Atmospheric greenhouse gas (GHG) concentrations are at unprecedented, record-high levels compared to the last 800 000 years. Those elevated GHG concentrations warm the planet and – partially offset by net cooling effects by aerosols – are largely responsible for the observed warming over the past 150 years. An accurate representation of GHG concentrations is hence important to understand and model recent climate change. So far, community efforts to create composite datasets of GHG concentrations with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since the 1980s. Here, we provide consolidated datasets of historical atmospheric concentrations (mole fractions) of 43 GHGs to be used in the Climate Model Intercomparison Project – Phase 6 (CMIP6) experiments. The presented datasets are based on AGAGE and NOAA networks, firn and ice core data, and archived air data, and a large set of published studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved and include seasonality. We focus on the period 1850–2014 for historical CMIP6 runs, but data are also provided for the last 2000 years. We provide consolidated datasets in various spatiotemporal resolutions for carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as 40 other GHGs, namely 17 ozone-depleting substances, 11 hydrofluorocarbons (HFCs), 9 perfluorocarbons (PFCs), sulfur hexafluoride (SF6), nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2). In addition, we provide three equivalence species that aggregate concentrations of GHGs other than CO2, CH4 and N2O, weighted by their radiative forcing efficiencies. For the year 1850, which is used for pre-industrial control runs, we estimate annual global-mean surface concentrations of CO2 at 284.3 ppm, CH4 at 808.2 ppb and N2O at 273.0 ppb. The data are available at https://esgf-node.llnl.gov/search/input4mips/ and http://www.climatecollege.unimelb.edu.au/cmip6. While the minimum CMIP6 recommendation is to use the global- and annual-mean time series, modelling groups can also choose our monthly and latitudinally resolved concentrations, which imply a stronger radiative forcing in the Northern Hemisphere winter (due to the latitudinal gradient and seasonality).

RATIONALE Past climate has always influenced human adaptation to the environment. In order to reconstruct palaeoclimate fluctuations and their role in the evolution of Near Eastern societies during the mid-Holocene, high-resolution Δ13 C records from fossil wood remains at the archaeological site of Arslantepe (eastern Turkey) have been developed. METHODS After chemical treatment, δ13 C values were measured by sample combustion flow using a FLASH EA-CHNS instrument interfaced with a Delta V isotope ratio mass spectrometer via a CONFLO III. Two replicates per sample were analysed. The measurement precision was evaluated by propagating variations of the δ13 C values of samples and V-PDB standards, whereas the accuracy was checked by a quality control sample. To account for changes in atmospheric CO2 , Δ13 C values were calculated. In addition, 14 C/12 C ratios were measured by means of ann AMS system (3 MV tandem accelerator). RESULTS Mean Δ13 C curves of deciduous Quercus and Juniperus from archaeological levels between 4700 and 2000 BC (Arslantepe periods VIII-VI D) were produced, where the isotope values were ordered by the available RC ages. Interspecific variations of evergreen vs deciduous plants were postulated for the juniper Δ13 C values being higher than 3‰. The seasonal rainfall amount was recorded by the juniper remains, while the water table levels were obtained from the oak samples. CONCLUSIONS The local climate experienced times of enhanced/reduced precipitation in concert with regional trends. Anomalies in the air mass circulation from the Mediterranean basin also produced oscillations of rainfall amount. In such a frame the Rapid Climate Change dry events had a consistent signature in the Arslantepe Δ13 C record, thus potentially contributing to social or organisational changes at the site.

We review the approaches for estimating biomass burning from ice-cores and consider the challenges and assumptions in their application. In particular, we consider the potential of biomarker proxies for biomass burning, hitherto not widely applied to glacial ice archives. We also review the available records of biomass burning in ice-cores and consider how variations in fire regimes have been related to atmospheric and land-use changes. Finally, we suggest that future developments in ice-core science should aim to combine multiple biomarkers with other records (black carbon, charcoal) and models to discern the types of material being burnt (C3 versus C4 plants, angiosperms, gymnosperms, peat fires, etc.) and to improve constraints on source areas of biomass burning. An ultimate goal is to compare the biomass burning record from ice-cores with hindcasts from models to project how future climate change will influence biomass burning and, inversely, how fire will affect climate.

Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000–11,650 yrs ago) allows us to disentangle ice-climate feedbacks that are key to improving future projections. Whilst the sequence of events during this period is reasonably well-known, relatively poor chronological control has precluded precise alignment of ice, atmospheric and marine records, making it difficult to assess relationships between Antarctic ice-sheet (AIS) dynamics, climate change and sea level. Here we present results from a highly-resolved ‘horizontal ice core’ from the Weddell Sea Embayment, which records millennial-scale AIS dynamics across this extensive region. Counterintuitively, we find AIS mass-loss across the full duration of the Antarctic Cold Reversal (ACR; 14,600–12,700 yrs ago), with stabilisation during the subsequent millennia of atmospheric warming. Earth-system and ice-sheet modelling suggests these contrasting trends were likely Antarctic-wide, sustained by feedbacks amplified by the delivery of Circumpolar Deep Water onto the continental shelf. Given the anti-phase relationship between inter-hemispheric climate trends across the LGT our findings demonstrate that Southern Ocean-AIS feedbacks were controlled by global atmospheric teleconnections. With increasing stratification of the Southern Ocean and intensification of mid-latitude westerly winds today, such teleconnections could amplify AIS mass loss and accelerate global sea-level rise.

This study describes the tests carried out to measure the isotopic composition of Boron (B) in water samples by use of the magnetic spectrometer and accelerator of the Center for Isotopic Research on Cultural and Environmental heritage (CIRCE) of Italy. B was extracted from water samples to obtain Boric acid (B(OH)3), which was then analyzed. We quantified the precision of our experimental system and the variability introduced by the chemical extraction measuring chemically untreated and treated pure B(OH)3samples. We found an instrumental precision around 10‰ (1σ), but, by increasing the number of replicates (>30), we obtained a standard deviation of the mean (σerr) around 3‰ or lower. We also tested whether the chemical extraction caused isotopic fractionation and found a small fractionation (ε = 5 ± 4‰) of treated samples normalized against untreated ones, compatible with zero at 2σ. In order to avoid δ11B biases, we decided to normalize unknown treated samples with treated standards. Finally, we measured δ11B of seawater and groundwater samples to test the analytical method, and obtained values of 30 ± 6‰ and −4 ± 4‰ respectively. We conclude that our experimental system is only suitable when remarkable (>10‰) δ11B differences exist among water samples, but cannot be used to measure natural differences (

This study has been supported by the French Dynamos project [ANR-07-BLAN-0222-01] and the Italian POLIGRID project [CUP B65B0900002007]; International audience; In this study, we evaluated trimethylsilyl (TMS) derivatives as derivatization reagents for the compound-specific stable carbon isotope analysis of soil amino acids by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). We used non-proteinogenic amino acids to show that the extraction-derivatization-analysis procedure provides a reliable method to measure delta C-13 values of amino acids extracted from soil. However, we found a number of drawbacks that significantly increase the final total uncertainty. These include the following: production of multiple peaks for each amino acid, identified as di-, tri- and tetra-TMS derivatives; a number of TMS-carbon (TMS-C) atoms added lower than the stoichiometric one, possibly due to incomplete combustion; different TMS-C delta C-13 for di-, tri- and tetra-TMS derivatives. For soil samples, only four amino acids (leucine, valine, threonine and serine) provide reliable delta C-13 values with a total average uncertainty of 1.3 parts per thousand. We conclude that trimethylsilyl derivatives are only suitable for determining the C-13 incorporation in amino acids within experiments using C-13-labelled tracers but cannot be applied for amino acids with natural carbon isotope abundance until the drawbacks described here are overcome and the measured total uncertainty significantly decreased.

The existence of a right to a full discovery which has become a practice in several jurisdictions, is seen by its opponents as a paper invasion. As arbitration scholars and practitioners well know, a lively debate has been going on about the discovery of documents.

The transition from the late Pleistocene to the Holocene (30 000–5000 years ago) was a period of considerable climate variability, which has been associated with changes in deep water formation and the intensity of the Meridional Overturning Circulation. Although numerous records exist across the North Atlantic region, few Antarctic ice core records have been obtained from the south. Here we exploit the potential of upwelling ancient ice – so-called blue ice areas (BIAs) – from the Patriot Hills in the Ellsworth Mountains to derive the first deuterium isotope record (δD) from continental Antarctica south of the Weddell Sea. Gas analysis and glaciological considerations provide a first relative chronology. Inferred temperature trends from the Patriot Hills BIA and snow pit suggest changing climate influences during the transition between the last glacial period and Holocene. Under modern conditions, the interplay between the Antarctic high-pressure system and the Southern Annular Mode appears to play a significant role in controlling katabatic wind flow over the site while the BIA record suggests that greater sea ice extent during the last glacial period was a major control. Our results demonstrate the considerable potential of the Patriot Hills site for reconstructing past climate change in the south Atlantic region.

[1] We present new measurements of δ13C of CO2 extracted from a high-resolution ice core from Law Dome (East Antarctica), together with firn measurements performed at Law Dome and South Pole, covering the last 150 years. Our analysis is motivated by the need to better understand the role and feedback of the carbon (C) cycle in climate change, by advances in measurement methods, and by apparent anomalies when comparing ice core and firn air δ13C records from Law Dome and South Pole. We demonstrate improved consistency between Law Dome ice, South Pole firn, and the Cape Grim (Tasmania) atmospheric δ13C data, providing evidence that our new record reliably extends direct atmospheric measurements back in time. We also show a revised version of early δ13C measurements covering the last 1000 years, with a mean preindustrial level of −6.50‰. Finally, we use a Kalman Filter Double Deconvolution to infer net natural CO2 fluxes between atmosphere, ocean, and land, which cause small δ13C deviations from the predominant anthropogenically induced δ13C decrease. The main features found from the previous δ13C record are confirmed, including the ocean as the dominant cause for the 1940 A.D. CO2 leveling. Our new record provides a solid basis for future investigation of the causes of decadal to centennial variations of the preindustrial atmospheric CO2 concentration. Those causes are of potential significance for predicting future CO2 levels and when attempting atmospheric verification of recent and future global carbon emission mitigation measures through Coupled Climate Carbon Cycle Models.

When the parties refer a dispute to arbitration, they generally use a standard arbitration agreement. Very important issues such as the coaching or non-coaching of witnesses, the role of the party appointed arbitrators, the deadline for amendments to claims and for evidence, and possible sanctions for delaying tactics, frequently remain undecided and give rise to very serious problems. These Optional Additions draw the parties' attention to these delicate issues and offer alternative solutions to them.

Atmospheric greenhouse gas concentrations are at unprecedented, record-high levels compared to pre-industrial reconstructions over the last 800,000 years. Those elevated greenhouse gas concentrations warm the planet and together with net cooling effects by aerosols, they are the reason of observed climate change over the past 150 years. An accurate representation of those concentrations is hence important to understand and model recent and future climate change. So far, community efforts to create composite datasets with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since 1980s. Here, we provide consolidated data sets of historical atmospheric (volume) mixing ratios of 43 greenhouse gases specifically for the purpose of climate model runs. The presented datasets are based on AGAGE and NOAA networks and a large set of literature studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved, and include seasonality over the period between year 0 to 2014. We assimilate data for CO2, methane (CH4) and nitrous oxide (N2O), 5 chlorofluorocarbons (CFCs), 3 hydrochlorofluorocarbons (HCFCs), 16 hydrofluorocarbons (HFCs), 3 halons, methyl bromide (CH3Br), 3 perfluorocarbons (PFCs), sulfur hexafluoride (SF6), nitrogen triflouride (NF3) and sulfuryl fluoride (SO2F2). We estimate 1850 annual and global mean surface mixing ratios of CO2 at 284.3 ppmv, CH4 at 808.2 ppbv and N2O at 273.0 ppbv and quantify the seasonal and hemispheric gradients of surface mixing ratios. Compared to earlier intercomparisons, the stronger implied radiative forcing in the northern hemisphere winter (due to the latitudinal gradient and seasonality) may help to improve the skill of climate models to reproduce past climate and thereby reduce uncertainty in future projections.

Homepage > Generale > Archivio > Archivio completo Surface water – groundwater connectivity implications on nitrate cycling assessed by means of hydrogeologic and isotopic techniques in the Alento river basin (Salerno, Italy): preliminary data Luisa Stellato(a), Brunella Di Rienzo(a), Egidio Di Fusco(a), Mauro Rubino(a), Fabio Marzaioli(a) & Vincenzo Allocca(b) Antonio Salluzzo (c), Juri Rimauro(c), Nunzio Romano(d) & Fulvio Celico(e) (a) Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE), Dip. di Matematica e Fisica, Seconda Università degli Studi di Napoli, Viale Lincoln, 5, 81100 Caserta, Italy. E-mail: luisa.stellato@unina2.it (b) Dipartimento di Scienze della Terra, dell'Ambiente e delle Risorse (DiSTAR), Università di Napoli Federico II,Via Mezzocannone, 8, 80134, Napoli, Italy. (c) ENEA - Research Center of Portici, UTTP-CHIA, Environmental Chemistry Laboratory, Piazzale E. Fermi, 1, 80055 Portici (Napoli), Italy. (d) Dept. of Agriculture, Division of Agricultural, Forest and Biosystems Engineering, Università di Napoli Federico II, Via Università, 100, 80055, Portici (Napoli), Italy. (e) Interdisciplinary Centre for Studies on Water Resources, Department of Physics and Earth Sciences "Macedonio Melloni", University of Parma, Parco Area delle Scienze, 157/A, 43124, Parma, Italy. DOI: 10.3301/ROL.2016.98 Pages: 80-83 Abstract The knowledge of the mechanisms regulating the concentration of nutrients in rivers is of fundamental importance in maintaining the ecological functioning of streams. In particular, in the riverbed sediments, where the biogeochemical activity is enhanced, the study of retention mechanisms becomes crucial in order to determine the restoring capacity of a watercourse. In case of groundwater inflow, hot-spots in the recycling of nutrients within the riparian and hyporheic zones can be observed, influencing the nutrient load transported into the stream depending on retention mechanisms. Hence, the study of biotic and abiotic factors affecting retention and transport of nutrients in a riverine ecosystem at different spatial scales (from reach to catchment) becomes fundamental to understand the mechanisms regulating the concentration of nutrients, and in particular nitrates, in streams. The present work is developed within the framework of the IAEA Coordinated Research Project (CRP) "Environmental Isotopes and Age Dating Methods to Assess Nitrogen Pollution and Other Quality Issues in Rivers". The main scope is to find a reliable methodology to, spatially and temporally, quantify groundwater inflows to a river in order to study nitrates contamination of a groundwater dependent river ecosystem. In particular, the overall objectives of the proposed project are: i) the identification and quantification of spatio-temporal variation of the connectivity between groundwater and surface water; ii) the identification of the nitrate contamination sources of shallow groundwater; iii) the study of the nitrates retention and recycling mechanisms in riverbed sediments in critical effluent river reaches (key sites) in order to determine the importance of hyporheic and riparian zones. Here, the preliminary results of the hydrogeological, chemical and isotopic (222Rn, δ18O, δD) monitoring are presented and discussed.

RATIONALE: The 6 th archaeological excavation campaign performed at the ’Pieve di Pava’ (San Giovanni d’Asso, Siena, Italy) unearthed a privileged stone burial of a single individual (US 2378), covered by a monolithic slab and placed in front of an altar. The skeletal remains of a young male (18–20 years old), not in anatomical connection, were found at the bottom floor of a tomb (160 cm long, 40 cm large and over 70 cm deep). METHODS: A multidisciplinary study has been carried out concerning that privileged bone burial. The study combines paleopathology studies, stable isotope palaeodietary reconstruction, radiocarbon dating and archaeological analyses. RESULTS: 14 C dating of the skeleton revealed a date between 650 and 688 AD. Stable isotope analysis (d 18 O, d 13 C, d 15 N) attested that he was probably a member of the local population, whose diet was rather rich in animal proteins. The paleopathological study diagnosed a case of acromesomelic dysplasia, a congenital anomaly with disproportion of the limbs. Archaeological evidence regarding the circular delimitation of the bones suggested that the skeleton was a secondary deposition, transported to the church in a sack. CONCLUSIONS: We argue that the relic was used for the re-consecration of the church, following the restoration work in the 8 th century. We conclude that the skeleton belonged to an eminent personage (e.g., either the member of a local elite

Three types of mediation (voluntary, court recommended, and now mandatory mediation) are in force in the Italian legal system. Mandatory mediation is provided for some classes of disputes and the mediator is appointed by a mediation centre which must satisfy the Ministry of Justice as to the existence of the statutory requirements for its existence. Mediators must possess a university degree and must have successfully followed a 50-hour training course. The new legislation has been the subject of agreement by some and of criticism by others. The mandatory nature of it is seen as the main highlight of this legislation, while the requirements for mediation centers and the training of mediators may be and should be improved.

The increasing number of disputes related to investment includes claims made by a party which is not the original investor, but which has inherited the original investment through a transfer of it. The transfer gives rise to various issues which are argued and decided in various ways.

We show the potentiality of coupling together different compound-specific isotopic analyses in a laboratory experiment, where (13)C-depleted leaf litter was incubated on a (13)C-enriched soil. The aim of our study was to identify the soil compounds where the C derived from three different litter species is retained. Three (13)C-depleted leaf litter (Liquidambar styraciflua L., Cercis canadensis L. and Pinus taeda L., delta(13)C(vsPDB) approximately -43 per thousand), differing in their degradability, were incubated on a C4 soil (delta(13)C(vsPDB) approximately -18 per thousand) under laboratory-controlled conditions for 8 months. At harvest, compound-specific isotope analyses were performed on different classes of soil compounds [i.e. phospholipids fatty acids (PLFAs), n-alkanes and soil pyrolysis products]. Linoleic acid (PLFA 18:2omega6,9) was found to be very depleted in (13)C (delta(13)C(vsPDB) approximately from -38 to -42 per thousand) compared to all other PLFAs (delta(13)C(vsPDB) approximately from -14 to -35 per thousand). Because of this, fungi were identified as the first among microbes to use the litter as source of C. Among n-alkanes, long-chain (C27-C31) n-alkanes were the only to have a depleted delta(13)C. This is an indication that not all of the C derived from litter in the soil was transformed by microbes. The depletion in (13)C was also found in different classes of pyrolysis products, suggesting that the litter-derived C is incorporated in less or more chemically stable compounds, even only after 8 months decomposition.

The mechanism by which judges make their decisions is one of the mysteries of the legal world. This raises the natural query whether the mechanism by which arbitrators make their decisions is the same or different from that of the judges. That mechanism is the same in the abstract, but different in practice. This article analyses the reasons for such differences.

A new AMS system has been installed at Center for Isotopic Research on Cultural and Environmental Heritage (CIRCE) in Caserta/ Italy. It was built by National Electrostatics Corp. Middleton, WI/USA, and arrived at CIRCE in the middle of January 2005; the installation and the acceptance tests were completed at the end of February 2005. At first, the system is intended for Radiocarbon AMS; for future Al and Be AMS only minor upgrades are needed and the magnets are designed to bend heavy isotopes like Uranium. Concerning Radiocarbon AMS, the first measurements of unknown samples, prepared in the internal preparation laboratory, already yielded results of high precision and C-14 dating is in full swing. (c) 2007 Elsevier B.V. All rights reserved.

The quickly rising atmospheric carbon dioxide (CO2)-levels, justify the need to explore all carbon (C) sequestration possibilities that might mitigate the current CO2 increase. Here, we report the likely impact of future increases in atmospheric CO2 on woody biomass production of three poplar species (Populus alba L. clone 2AS-11, Populus nigra L. clone Jean Pourtet and Populuseuramericana clone I-214). Trees were growing in a high-density coppice plantation during the second rotation (i.e., regrowth after coppice; 2002-2004; POPFACE/EUROFACE). Six plots were studied, half of which were continu- ously fumigated with CO2 (FACE; free air carbon dioxide enrichment of 550 ppm). Half of each plot was fertilized to study the interaction between CO2 and nutrient fertilization. At the end of the second rotation, selective above- and belowground harvests were performed to estimate the productivity of this bio-energy plantation. Fertilization did not affect growth of the poplar trees, which was likely because of the high rates of ferti- lization during the previous agricultural land use. In contrast, elevated CO2 enhanced biomass production by up to 29%, and this stimulation did not differ between above- and belowground parts. The increased initial stump size resulting from elevated CO2 during the first rotation (1999-2001) could not solely explain the observed final biomass increase. The larger leaf area index after canopy closure and the absence of any major photo- synthetic acclimation after 6 years of fumigation caused the sustained CO2-induced biomass increase after coppice. These results suggest that, under future CO2 concentra- tions, managed poplar coppice systems may exhibit higher potential for C sequestration and, thus, help mitigate climate change when used as a source of C-neutral energy.

A systematic analysis of efficiency, reproducibility and accuracy of cryogenic purification of CO(2) from air samples for isotopic analyses is presented. The technical characteristics of the cryogenic line are given in detail. To study the cryogenic process, three different operating parameters are considered: flow rate of the gas entering the line, pressure of the gas in the line, and CO(2)-trap shape. Experimental results demonstrate that efficiency, reproducibility and accuracy strongly depend on the CO(2)trap shape. Moreover, a dependence of reproducibility and accuracy on the flow rate of the gas is found, but not on its pressure. High precision (< or =0.02 per thousand for delta(13)C and < or =0.05 per thousand for delta(18)O) and good accuracy (

Mauro Rubino-Sammartano, of Milan, Italy, discusses European alternatives to arbitration that have proven effective in resolving commercial disputes in a variety of forums.