bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulating the integrated summertime Δ14CO2 signature from anthropogenic emissions over Western Europe
Authors: Bozhinova D. , van der Molen M. K. , van der Velde I. R. , Krol M. C. , van der Laan S. , Meijer H. A. J. , Peters W.
Published: July 2014

Abstract. Radiocarbon dioxide (14CO2, reported in Δ14CO2) can be used to determine the fossil fuel CO2 addition to the atmosphere, since fossil fuel CO2 no longer contains any 14C. After the release of CO2 at the source, atmospheric transport causes dilution of strong local signals into the background and detectable gradients of Δ14CO2 only remain in areas with high fossil fuel emissions. This fossil fuel signal can moreover be partially masked by the enriching effect that anthropogenic emissions of 14CO2 from the nuclear industry have on the atmospheric Δ14CO2 signature. In this paper, we investigate the regional gradients in 14CO2 over the European continent and quantify the effect of the emissions from nuclear industry. We simulate the emissions and transport of fossil fuel CO2 and nuclear 14CO2 for Western Europe using the Weather Research and Forecast model (WRF-Chem) for a period covering 6 summer months in 2008. We evaluate the expected CO2 gradients and the resulting Δ14CO2 in simulated integrated air samples over this period, as well as in simulated plant samples. We find that the average gradients of fossil fuel CO2 in the lower 1200 m of the atmosphere are close to 15 ppm at a 12 km × 12 km horizontal resolution. The nuclear influence on Δ14CO2 signatures varies considerably over the domain and for large areas in France and the UK it can range from 20 to more than 500% of the influence of fossil fuel emissions. Our simulations suggest that the resulting gradients in Δ14CO2 are well captured in plant samples, but due to their time-varying uptake of CO2, their signature can be different with over 3‰ from the atmospheric samples in some regions. We conclude that the framework presented will be well-suited for the interpretation of actual air and plant 14CO2 samples.
Air quality in the mid-21st century for the city of Paris under two climate scenarios; from the regional to local scale
Authors: Markakis K. , Valari M. , Colette A. , Sanchez O. , Perrussel O. , Honore C. , Vautard R. , Klimont Z. , Rao S.
Published: July 2014

Abstract. Ozone and PM2.5 concentrations over the city of Paris are modeled with the CHIMERE air-quality model at 4 km × 4 km horizontal resolution for two future emission scenarios. A high-resolution (1 km × 1 km) emission projection until 2020 for the greater Paris region is developed by local experts (AIRPARIF) and is further extended to year 2050 based on regional-scale emission projections developed by the Global Energy Assessment. Model evaluation is performed based on a 10-year control simulation. Ozone is in very good agreement with measurements while PM2.5 is underestimated by 20% over the urban area mainly due to a large wet bias in wintertime precipitation. A significant increase of maximum ozone relative to present-day levels over Paris is modeled under the "business-as-usual" scenario (+7 ppb) while a more optimistic "mitigation" scenario leads to a moderate ozone decrease (−3.5 ppb) in year 2050. These results are substantially different to previous regional-scale projections where 2050 ozone is found to decrease under both future scenarios. A sensitivity analysis showed that this difference is due to the fact that ozone formation over Paris at the current urban-scale study is driven by volatile organic compound (VOC)-limited chemistry, whereas at the regional-scale ozone formation occurs under NOx-sensitive conditions. This explains why the sharp NOx reductions implemented in the future scenarios have a different effect on ozone projections at different scales. In rural areas, projections at both scales yield similar results showing that the longer timescale processes of emission transport and ozone formation are less sensitive to model resolution. PM2.5 concentrations decrease by 78% and 89% under business-as-usual and mitigation scenarios, respectively, compared to the present-day period. The reduction is much more prominent over the urban part of the domain due to the effective reductions of road transport and residential emissions resulting in the smoothing of the large urban increment modeled in the control simulation.
Observations of rapid aerosol optical depth enhancements in the vicinity of polluted cumulus clouds
Authors: Eck T. F. , Holben B. N. , Reid J. S. , Arola A. , Ferrare R. A. , Hostetler C. A. , Crumeyrolle S. N. , Berkoff T. A. , Welton E. J. , Lolli S. , Lyapustin A. , Wang Y. , Schafer J. S. , Giles D. M. , Anderson B. E. , Thornhill K. L. , Minnis P. , Pickering K. E. , Loughner C. P. , Smirnov A. , Sinyuk A.
Published: July 2014

Abstract. During the July 2011 DISCOVER-AQ field experiment in Maryland, significant enhancements in AERONET sun-sky radiometer measured AOD were observed in the immediate vicinity of non-precipitating cumulus clouds on some days. Both measured Angstrom exponents and aerosol size distribution retrievals made before, during and after cumulus development often suggest little change in fine mode particle size, therefore implying possible new particle formation in addition to cloud processing and humidification of existing particles. In addition to sun/sky radiometer measurements of large enhancements of fine mode AOD, lidar measurements made from both ground-based and aircraft-based instruments during the experiment also measured large increases in aerosol signal at altitudes associated with the presence of fair weather cumulus clouds. These data show modifications of the aerosol vertical profile as a result of the aerosol enhancements at and below cloud altitudes. The airborne lidar data were utilized to estimate the spatial extent of these aerosol enhancements, finding increased AOD, backscatter and extinction out to 2.5 km distance from the cloud edge. Furthermore, in situ measurements made from aircraft vertical profiles over an AERONET site during the experiment also showed large increases in aerosol scattering and aerosol volume after cloud formation as compared to before. The 15 year AERONET database of AOD measurements at the GSFC, Maryland site was investigated in order to obtain a climatological perspective of this phenomenon of AOD enhancement. Analysis of the diurnal cycle of AOD in summer showed significant increases in AOD from morning until late afternoon, corresponding to the diurnal cycle of cumulus development.
An analysis of the impacts of VOCs and NOx on the ozone formation in Guangzhou
Authors: Zou Y. , Deng X. J. , Wang B. G. , Li F. , Tan H. B. , Deng T. , Mai B. R. , Liu X. T.
Published: July 2014

Abstract. In this study, online monitoring instruments were used to monitor ozone, NOx and VOCs at the Guangzhou Panyu Atmospheric Composition Station (GPACS) of the China Meteorological Administration from June 2011 to May 2012, so as to obtain their characteristic seasonal and diurnal variations, as well as the impacts of NOx and VOCs on local ozone formation and Guangzhou ozone control strategies. The results show that during the observation period the seasonal variation of ozone concentration was lower in the spring and winter and higher in the summer and autumn, which is contrary that of NOx and VOCs. At around 09:00 LT in the summer, autumn and winter, both the ozone concentration and NO2/NO ratio begin to increase, and the NO2/NO ratio reached its maximum after a peak of ozone concentration, but this variation was not particularly evident in the spring. Aromatics and alkenes are the largest components for ozone formation potential, among which aromatic toluene, m-xylene, p-xylene and 1,3,5-trimethylbenzene are the most important components, with a total contribution of about 31.6% to ozone formation potential. Through the analysis on local ozone control by the VOC/NOX ratio, it was found that when the ozone concentration reached a peak in the summer and autumn in which high concentrations of ozone were prone to occur, ozone generation was NOx limited, thus NOx emissions must be controlled to regulate the occurrence of high-concentration ozone events. In the spring and winter, ozone generation was always VOCs controlled. Due to the relatively low ozone concentration, although NOx emissions could be controlled to increase ozone concentration, high-concentration ozone events would not occur. Therefore, for the control of ozone in Guangzhou, in addition to the control of VOCs emissions, more attention must be paid to reducing NOx emissions, so as to achieve the purpose of controlling high-concentration ozone.
Distinguishing cirrus cloud presence in autonomous lidar measurements
Authors: Campbell J. R. , Vaughan M. A. , Oo M. , Holz R. E. , Lewis J. R. , Welton E. J.
Published: July 2014

Abstract. Level 2 Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite-based cloud datasets from 2012 are investigated for metrics that help distinguish the cirrus cloud presence of in autonomous lidar measurements, using temperatures, heights, optical depth and phase. A thermal threshold, proposed by Sassen and Campbell (2001; SC2001) for cloud top temperature Ttop ≤ −37 °C, is evaluated vs. CALIOP algorithms that identify ice-phase cloud layers alone using depolarized backscatter. Global mean cloud top heights (11.15 vs. 10.07 km a.m.s.l.), base heights (8.76 vs. 7.95 km a.m.s.l.), temperatures (−58.48 °C vs. −52.18 °C and −42.40 °C vs. −38.13 °C, respectively for tops and bases) and optical depths (1.18 vs. 1.23) reflect the sensitivity to these competing constraints. Over 99% of all Ttop ≤ −37 °C clouds are classified as ice by CALIOP Level 2 algorithms. Over 81% of all ice clouds correspond with Ttop ≤ −37 °C. For instruments lacking polarized measurements, and thus practical phase estimates, Ttop ≤ −37 °C proves stable for distinguishing cirrus, as opposed to the risks of glaciated liquid water cloud contamination occurring in a given sample from clouds identified at warmer temperatures. Uncertainties in temperature profiles use to collocate with lidar data (i.e., model reanalyses/sondes) may justifiably relax the Ttop ≤ −37 °C threshold to include warmer cases. The ambiguity of "warm" (Ttop > −37 °C) ice cloud genus cannot be reconciled completely with available measurements, however, conspicuously including phase. Cloud top heights and optical depths are evaluated as potential constraints, as functions of CALIOP-retrieved phase. However, these data provide, at best, additional constraint in regional samples, compared with temperature alone, and may exacerbate classification uncertainties overall globally.
A semi-automated system for quantifying the oxidative potential of ambient particles in aqueous extracts using the dithiothreitol (DTT) assay: results from the Southeastern Center for Air Pollution and Epidemiology (SCAPE)
Authors: Fang T. , Verma V. , Guo H. , King L. E. , Edgerton E. S. , Weber R. J.
Published: July 2014

Abstract. A variety of methods are used to measure the capability of particulate matter (PM) to catalytically generate reactive oxygen species (ROS) in vivo, also defined as the aerosol oxidative potential. A widely used measure of aerosol oxidative potential is the dithiothreitol (DTT) assay, which monitors the depletion of DTT (a surrogate for cellular antioxidants) as catalyzed by the redox-active species in PM. However, a major constraint in the routine use of the DTT assay for integrating it with the large-scale health studies is its labor-intensive and time-consuming protocol. To specifically address this concern, we have developed a semi-automated system for quantifying the oxidative potential of aerosol liquid extracts using the DTT assay. The system, capable of unattended analysis at one sample per hour, has a high analytical precision (Coefficient of Variation of 12% for standards, 4% for ambient samples), and reasonably low limit of detection (0.31 nmol min−1). Comparison of the automated approach with the manual method conducted on ambient samples yielded good agreement (slope = 1.08 ± 0.12, r2 = 0.92, N = 9). The system was utilized for the Southeastern Center for Air Pollution and Epidemiology (SCAPE) to generate an extensive data set on DTT activity of ambient particles collected from contrasting environments (urban, road-side, and rural) in the southeastern US. We find that water-soluble PM2.5 DTT activity on a per air volume basis was spatially uniform and often well correlated with PM2.5 mass (r = 0.49 to 0.88), suggesting regional sources contributing to the PM oxidative potential in southeast US. However, the greater heterogeneity in the intrinsic DTT activity (per PM mass basis) across seasons indicates variability in the DTT activity associated with aerosols from sources that vary with season. Although developed for the DTT assay, the instrument can also be used to determine oxidative potential with other acellular assays.
Cloud radiative forcing intercomparison between fully coupled CMIP5 models and CERES satellite data
Authors: Calisto M. , Folini D. , Wild M. , Bengtsson L.
Published: July 2014

Abstract. In this paper, radiative fluxes for 10 years from 11 models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and from CERES satellite observations have been analyzed and compared. Under present-day conditions, the majority of the investigated CMIP5 models show a tendency towards a too-negative global mean net cloud radiative forcing (NetCRF) as compared to CERES. A separate inspection of the long-wave and shortwave contribution (LWCRF and SWCRF) as well as cloud cover points to different shortcomings in different models. Models with a similar NetCRF still differ in their SWCRF and LWCRF and/or cloud cover. Zonal means mostly show excessive SWCRF (too much cooling) in the tropics between 20° S and 20° N and in the midlatitudes between 40 to 60° S. Most of the models show a too-small/too-weak LWCRF (too little warming) in the subtropics (20 to 40° S and N). Difference maps between CERES and the models identify the tropical Pacific Ocean as an area of major discrepancies in both SWCRF and LWCRF. The summer hemisphere is found to pose a bigger challenge for the SWCRF than the winter hemisphere. The results suggest error compensation to occur between LWCRF and SWCRF, but also when taking zonal and/or annual means. Uncertainties in the cloud radiative forcing are thus still present in current models used in CMIP5.
Technical Note: Simple formulations and solutions of the dual-phase diffusive transport for biogeochemical modeling
Authors: Tang J. Y. , Riley W. J.
Published: July 2014

Abstract. Representation of gaseous diffusion in variably saturated near-surface soils is becoming more common in land biogeochemical models, yet the formulations and numerical solution algorithms applied vary widely. We present three different but equivalent formulations of the dual-phase (gaseous and aqueous) tracer diffusion transport problem that is relevant to a wide class of volatile tracers in land biogeochemical models. Of these three formulations (i.e., the gas-primary, aqueous-primary, and bulk-tracer-based formulations), we contend that the gas-primary formulation is the most convenient for modeling tracer dynamics in biogeochemical models. We then provide finite volume approximation to the gas-primary equation and evaluate its accuracy against three analytical models: one for steady-state soil CO2 dynamics, one for steady-state soil CH4 dynamics, and one for transient tracer diffusion from a constant point source into two different sequentially aligned medias. All evaluations demonstrated good accuracy of the numerical approximation. We expect our result will standardize an efficient mechanistic numerical method for solving relatively simple, multi-phase, one-dimensional diffusion problems in land models.
Identifying environmental controls on vegetation greenness phenology through model-data integration
Authors: Forkel M. , Carvalhais N. , Schaphoff S. , v. Bloh W. , Migliavacca M. , Thurner M. , Thonicke K.
Published: July 2014

Abstract. Existing dynamic global vegetation models (DGVMs) have a~limited ability in reproducing phenology and decadal dynamics of vegetation greenness as observed by satellites. These limitations in reproducing observations reflect a poor understanding and description of the environmental controls on phenology, which strongly influence the ability to simulate longer term vegetation dynamics, e.g. carbon allocation. Combining DGVMs with observational data sets can potentially help to revise current modelling approaches and thus to enhance the understanding of processes that control seasonal to long-term vegetation greenness dynamics. Here we implemented a~new phenology model within the LPJmL (Lund Potsdam Jena managed lands) DGVM and integrated several observational data sets to improve the ability of the model in reproducing satellite-derived time series of vegetation greenness. Specifically, we optimized LPJmL parameters against observational time series of the fraction of absorbed photosynthetic active radiation (FAPAR), albedo and gross primary production to identify the main environmental controls for seasonal vegetation greenness dynamics. We demonstrated that LPJmL with new phenology and optimized parameters better reproduces seasonality, inter-annual variability and trends of vegetation greenness. Our results indicate that soil water availability is an important control on vegetation phenology not only in water-limited biomes but also in boreal forests and the arctic tundra. Whereas water availability controls phenology in water-limited ecosystems during the entire growing season, water availability co-modulates jointly with temperature the beginning of the growing season in boreal and arctic regions. Additionally, water availability contributes to better explain decadal greening trends in the Sahel and browning trends in boreal forests. These results emphasize the importance of considering water availability in a new generation of phenology modules in DGVMs in order to correctly reproduce observed seasonal to decadal dynamics of vegetation greenness.
North America's net terrestrial carbon exchange with the atmosphere 1990–2009
Authors: King A. W. , Andres R. J. , Davis K. J. , Hafer M. , Hayes D. J. , Huntzinger D. N. , de Jong B. , Kurz W. A. , McGuire A. D. , Vargas R. , Wei Y. , West T. O. , Woodall C. W.
Published: July 2014

Abstract. Scientific understanding of the global carbon cycle is required for developing national and international policy to mitigate fossil-fuel CO2 emissions by managing terrestrial carbon uptake. Toward that understanding and as a contribution to the REgional Carbon Cycle Assessment and Processes (RECCAP) project, this paper provides a synthesis of net land–atmosphere CO2 exchange for North America over the period (1990–2009). This synthesis is based on results from three different methods: atmospheric inversion, inventory-based methods and terrestrial biosphere modeling. All methods indicate that the North America land surface was a sink for atmospheric CO2, with a net transfer from atmosphere to land. Estimates ranged from −890 to −280 Tg C yr−1, where the atmospheric inversion estimate forms the lower bound of that range (a larger land-sink) and the inventory-based estimate the upper (a smaller land sink). Integrating across estimates, "best" estimates (i.e., measures of central tendency) are −472 ± 281 Tg C yr−1 based on the mean and standard deviation of the distribution and −360 Tg C yr−1 (with an interquartile range of −496 to −337) based on the median. Considering both the fossil-fuel emissions source and the land sink, our analysis shows that North America was, however, a net contributor to the growth of CO2 in the atmosphere in the late 20th and early 21st century. The continent's CO2 source to sink ratio for this time period was likely in the range of 4 : 1 to 3 : 1.
Sensitivity simulations with direct shortwave radiative forcing by aeolian dust during glacial cycles
Authors: Bauer E. , Ganopolski A.
Published: July 2014

Abstract. Possible feedback effects between aeolian dust, climate and ice sheets are studied for the first time with an Earth system model of intermediate complexity over the late Pleistocene period. Correlations between climate and dust deposition records suggest that aeolian dust potentially plays an important role for the evolution of glacial cycles. Here climatic effects from the dust direct radiative forcing (DRF) caused by absorption and scattering of solar radiation are investigated. Key elements controlling the dust DRF are the atmospheric dust distribution and the absorption-scattering efficiency of dust aerosols. Effective physical parameters in the description of these elements are varied within uncertainty ranges known from available data and detailed model studies. Although the parameters can be reasonably constrained, the simulated dust DRF spans a~wide uncertainty range related to the strong nonlinearity of the Earth system. In our simulations, the dust DRF is highly localized. Medium-range parameters result in negative DRF of several watts per square metre in regions close to major dust sources and negligible values elsewhere. In the case of high absorption efficiency, the local dust DRF can reach positive values and the global mean DRF can be insignificantly small. In the case of low absorption efficiency, the dust DRF can produce a significant global cooling in glacial periods, which leads to a doubling of the maximum glacial ice volume relative to the case with small dust DRF. DRF-induced temperature and precipitation changes can either be attenuated or amplified through a feedback loop involving the dust cycle. The sensitivity experiments suggest that depending on dust optical parameters, dust DRF has the potential to either damp or reinforce glacial–interglacial climate changes.
Technical Note: Bed conduction impact on fiber optic DTS water temperature measurements
Authors: O'Donnell Meininger T. , Selker J. S.
Published: July 2014

Abstract. Error in Distributed Temperature Sensor (DTS) water temperature measurements may be introduced by contact of the fiber optic cable sensor with bed materials (e.g., seafloor, lakebed, stream bed). Heat conduction from the bed materials can affect cable temperature and the resulting DTS measurements. In the Middle Fork John Day River, apparent water temperature measurements were influenced by cable sensor contact with aquatic vegetation and fine sediment bed materials. Affected cable segments measured a diurnal temperature range reduced by 10% and lagged by 20–40 min relative to that of ambient stream temperature. The diurnal temperature range deeper within the vegetation–sediment bed material was reduced 70% and lagged 240 min relative to ambient stream temperature. These site-specific results illustrate the potential magnitude of bed-conduction impacts with buried DTS measurements. Researchers who deploy DTS for water temperature monitoring should understand the importance of the environment into which the cable is placed on the range and phase of temperature measurements.
Simultaneously assimilating multivariate data sets into the two-source evapotranspiration model by Bayesian approach: application to spring maize in an arid region of northwestern China
Authors: Zhu G. F. , Li X. , Su Y. H. , Zhang K. , Bai Y. , Ma J. Z. , Li C. B. , Hu X. L. , He J. H.
Published: July 2014

Abstract. Based on direct measurements of half-hourly canopy evapotranspiration (ET; W m−2) using the eddy covariance (EC) system and daily soil evaporation (E; mm day−1) using microlysimeters over a crop ecosystem in arid northwestern China from 27 May to 14 September in 2013, a Bayesian method was used to simultaneously parameterize the soil surface and canopy resistances in the Shuttleworth–Wallace (S–W) model. Four of the six parameters showed relatively larger uncertainty reductions (> 50%), and their posterior distributions became approximately symmetric with distinctive modes. There was a moderately good agreement between measured and simulated values of half-hourly ET and daily E with a linear regression being y = 0.84 x + 0.18 (R2 = 0.83) and y = 1.01 x + 0.01 (R2 = 0.82), respectively. The causes of underestimations of ET by the S–W model was possibly attributed to the microscale advection, which can contribute an added energy in the form of downward sensible heat fluxes to the ET process. Therefore, the advection process should be taken into account in simulating ET in heterogeneous land surfaces. Also, underestimations were observed on or shortly after rainy days, which may be due to direct evaporation of liquid water intercepted in the canopy. Thus, the canopy interception model should be coupled to the S–W model in the long-term ET simulation.
Evaluation of Mekong River commission operational flood forecasts, 2000–2012
Authors: Pagano T. C.
Published: July 2014

Abstract. This study created a 13-year historical archive of operational flood forecasts issued by the Regional Flood Management and Mitigation Center (RFMMC) of the Mekong River Commission. The RFMMC issues 1- to 5-day daily deterministic river height forecasts for 22 locations throughout the wet season (June–October). When these forecasts reach near flood level, government agencies and the public are encouraged to take protective action against damages. When measured by standard skill scores, the forecasts perform exceptionally well (e.g., 1 day-ahead Nash–Sutcliffe > 0.99) although much of this apparent skill is due to the strong seasonal cycle and the narrow natural range of variability at certain locations. Five-day forecasts upstream of Phnom Penh typically have 0.8 m error standard deviation, whereas below Phnom Penh the error is typically 0.3 m. The coefficients of persistence for 1-day forecasts are typically 0.4–0.8 and 5-day forecasts are typically 0.1–0.7. RFMMC uses a series of benchmarks to define a metric of percentage satisfactory forecasts. As the benchmarks were derived based on the average error, certain locations and lead times consistently appear less satisfactory than others. Instead, different benchmarks were proposed and derived based on the 70th percentile of absolute error over the 13-year period. There are no obvious trends in the percentage of satisfactory forecasts from 2002 to 2012, regardless of the benchmark chosen. Finally, when evaluated from a categorical "crossing above/not-crossing above flood level" perspective, the forecasts have a moderate probability of detection (48% at 1 day ahead, 31% at 5 days ahead) and false alarm rate (13% at 1 day ahead, 74% at 5 days ahead).
A geographical and seasonal comparison of nitrogen uptake by phytoplankton in the Southern Ocean
Authors: Philibert R. , Waldron H. , Clark D.
Published: July 2014

Abstract. Primary production in the Southern Ocean has been shown to be regulated by light and nutrients (such as silicate and iron) availability. However, the impact of these factors vary seasonally and differ from region to region. The seasonal cycle of primary production in this region is not fully resolved over an annual scale due to the lack of winter in situ measurements. In this study, nitrate and ammonium uptake rates were measured using 15N tracers during a winter cruise in July 2012 and a summer cruise in February/March 2013. In winter, nitrogen uptake rates were measured at 55% and 1% of the surface photosynthetically active radiation (sPAR). The summer uptake rates were measured at 4 light depths corresponding to 55, 30, 10 and 3% sPAR. The integrated nitrate uptake rates during the winter cruise ranged from 0.16–5.20 (average 1.14) mmol N m−2 d−1 while the ammonium uptake rates ranged from 0.6–32.8 (average 6.72) mmol N m−2 d−1. During the summer cruise, the mean integrated nitrate uptake rate was 0.34 mmol N m−2 d−1 with a range between 0.16–0.65 mmol N m−2 d−1. The integrated ammonium uptake rate averaged 5.61 mmol N m−2 d−1 and ranged from 1.44–11.28 mmol N m−2 d−1. The factors controlling primary production in winter and summer were investigated. During the winter cruise, it was found the different nitrogen uptake regimes were not separated by fronts. Light (in terms of day length) and ammonium concentration had the most influence on the nitrogen uptake regime. In the summer, increases in the mixed layer depth (MLD) resulted in increased nitrogen uptake rates. This suggests that the increases in the MLD could be alleviating nutrient limitations experienced by the phytoplankton at the end of summer.
Furfural and its biochar improve the general properties of a saline soil
Authors: Wu Y. , Xu G. , Shao H. B.
Published: July 2014

Abstract. Organic materials (e.g., furfural residue) are generally believed to improve the physical and chemical properties of saline soils with low fertility. Recently, biochar has been received more attention as a possible measure to improve the carbon balance and improve soil quality in some degraded soils. However, little is known about their different amelioration of a sandy saline soil. In this study, 56 d incubation experiment was conducted to evaluate the influence of furfural and its biochar on the properties of saline soil. The results showed that both furfural and biochar greatly reduced pH, increased soil organic carbon (SOC) content and cation exchange capacity (CEC), and enhanced the available phosphorus (P) in the soil. Furfural is more efficient than biochar in reducing pH: 5% furfural lowered the soil pH by 0.5–0.8 (soil pH: 8.3–8.6), while 5% biochar decreased by 0.25–0.4 due to the loss of acidity in pyrolysis process. With respect to available P, furfural addition at a rate of 5% increased available P content by 4–6 times in comparison to 2–5 times with biochar application. In reducing soil exchangeable sodium percentage (ESP), biochar is slightly superior to furfural because soil ESP reduced by 51% and 43% with 5% furfural and 5% biochar at the end of incubation. In addition, no significant differences were observed between furfural and biochar about their capacity to retain N, P in leaching solution and to increase CEC in soil. These facts may be caused by the relatively short incubation time. In general, furfural and biochar exhibited a different effect depending on the property: furfural was more effective in decreasing pH and increasing available P, whereas biochar played a more important role in increasing SOC and reducing ESP of saline soil.
Using the Nordic Geodetic Observing System for land uplift studies
Authors: Nordman M. , Poutanen M. , Kairus A. , Virtanen J.
Published: July 2014

Abstract. Geodetic observing systems have been planned and developed during the last decade. An ideal observing system consists of a network of geodetic observing stations with several techniques at the same site, publicly accessible databases, and as a product delivers data time series, combination of techniques or some other results obtained from the data sets. Globally, there is the International Association of Geodesy (IAG) Global Geodetic Observing System (GGOS), and there are ongoing attempts to create also regional observing systems. In this paper we introduce one regional system, the Nordic Geodetic Observing System (NGOS) hosted by the Nordic Geodetic Commission (NKG). Data availability and accessibility are one of the major issues today. We discuss in general data-related topics, and introduce a pilot database project of NGOS. As a demonstration of the use of such a database, we apply it for postglacial rebound studies in the Fennoscandian area. We compare land uplift values from three techniques, GNSS, tide gauges and absolute gravity, with the Nordic Geodetic Commission NKG2005LU land uplift model for Fennoscandia. The purpose is to evaluate the data obtained from different techniques and different sources and get the most reliable values for the uplift using publicly available data. The primary aim of observing systems will be to produce data and other products needed by multidisciplinary projects, such as Upper Mantle Dynamics and Quaternary Climate in Cratonic Areas (DynaQlim) or the European Plate Observing System (EPOS), but their needs may currently exceed the scope of an existing observing system. We discuss what requirements the projects pose to observing systems and their development. To make comparisons between different studies possible and reliable, the researcher should document what they have in detail, either in appendixes, supplementary material or some other available format.
Analogue experiments of salt flow and pillow growth due basement faulting and differential loading
Authors: Warsitzka M. , Kley J. , Kukowski N.
Published: July 2014

Abstract. Basement faulting is widely acknowledged as a potential trigger for salt flow and the growth of salt structures in salt-bearing extensional basins. In this study, dynamically scaled analogue experiments were designed to examine the evolution of salt pillows and the kinematics of salt flow due to a short pulse of basement faulting and a long-lasting phase of successive sedimentation. Experiments performed in the framework of this study consist of viscous silicone putty to simulate ductile rock salt, and a PVC-beads-quartz sand mixture representing a brittle supra-salt layer. In order to derive 2-D incremental displacement and strain patterns, the analogue experiments were monitored by an optical image correlation system (Particle Imaging Velocimetry). By varying layer thicknesses and extension rates, the influence of these parameters on the kinematics of salt flow were tested. Model results reveal that significant strain is triggered in the viscous layer by minor basement faulting. During basement extension downward flow occurs in the viscous layer above the basement fault tip. In contrast, upward flow takes place during post-extensional sedimentation. Lateral redistribution of the viscous material during post-extensional sedimentation is associated with subsidence above the footwall block and uplift adjacent to the basement faults leading to the formation of pillow structures (primary pillows). Decoupled cover faulting and the subsidence of peripheral sinks adjacent to the primary pillow causes the formation of additional pillow structures at large distance from the basement fault (secondary pillows). Experimental results demonstrate that the development of salt pillows can be triggered by basement extension, but requires a phase of tectonic quiescence. The potential for pillow growth and the displacement rate in the viscous layer increase with increasing thickness of the viscous layer and increasing extension rate, but decrease with increasing thickness of the overburden. The experimentally obtained structures resemble those of some natural extensional basins, e.g. the North German Basin or the Mid-Polish Trough, and can help to understand the kinematics during the structural evolution.
Expert modelling of a geological cross-section from boreholes: sources of uncertainty and their quantification
Authors: Lark R. M. , Thorpe S. , Kessler H. , Mathers S. J.
Published: July 2014

Abstract. We conducted a designed experiment to quantify sources of uncertainty in the expert interpretation of a geological cross-section. A group of 28 geologists participated in the experiment. Each interpreted borehole records which included three Palaeogene bedrock units, including the target unit for the experiment: the London Clay. The set of boreholes was divided into batches from which validation boreholes had been withheld; as a result we obtained 129 point comparisons between the interpreted elevation of the base of the London Clay and its observed elevation in a borehole not used for that particular interpretation. Analysis of the results showed good general agreement between the observed and interpreted elevations, with no evidence of systematic bias. Between-site variation of the interpretation error was spatially correlated, and the variance appeared to be stationary. The between-geologist component of variance was smaller overall, and depended on distance to the nearest borehole. There was also evidence that the between-geologist variance depends on the degree of experience of the individual. We used the statistical model of interpretation error to compute confidence intervals for any one interpretation of the base of the London Clay on the cross-section, and to provide uncertainty measures for decision support in a hypothetical route-planning process. The statistical model could also be used to quantify error-propagation in a full 3-D geological model produced from interpreted cross sections.
Evolução e diferenciação dos sistemas agrários nos Campos de Cima da Serra: origem dos pecuaristas familiares produtores do Queijo Serrano
Authors: Ambrosini Larissa Bueno , Miguel Lovois De Andrade , Filippi Eduardo Ernesto
Published: July 2014

O tema do presente trabalho é a evolução dos sistemas agrários na região dos Campos de Cima da Serra (CCS), situada no nordeste do Estado do Rio Grande do Sul. Buscamos a reconstituição histórica da ocupação desta região, desde seus primeiros habitantes, os índios, a fim de acompanhar a história do modo de exploração do meio e compreender como o mesmo evoluiu até sua estrutura atual, tendo como foco dois objetivos específicos: encontrar referências históricas dando conta da produção do queijo serrano (QS) e buscar as origens dos pecuaristas familiares dos CCS. Os pecuaristas familiares são produtores que se dedicam à bovinocultura de corte em empreendimentos onde a mão de obra é familiar, o tamanho das propriedades é considerado pequeno para a atividade e a racionalidade econômica prioriza a reprodução social da família. Nos CCS, uma das alternativas para complementar a renda dos pecuaristas familiares é a produção do QS. Nesse trabalho, utilizamos como instrumento de análise a Teoria dos Sistemas Agrários, o que permitiu reconstituir a história da interação da sociedade com seu meio natural e verificar que o QS é um patrimônio cultural dos CCS.
Limites físicos do crescimento econômico e progresso tecnológico: o debate The Limits to Growth versus Sussex
Authors: Saes Beatriz Macchione , Miyamoto Bruno César Brito
Published: July 2014

Nos anos 70 do século XX, a crescente preocupação com a degradação ambiental provocada pela atividade humana na busca do progresso material fez emergir, tanto nos círculos científicos como na sociedade, um debate intenso que abordava as limitações físicas impostas pelo ambiente ao crescimento econômico. No início da década, os pesquisadores do Science Policy Research Unit (SPRU) da Universidade de Sussex, na Inglaterra, no contexto desse debate, produziram uma extensa crítica ao célebre relatório The Limits to Growth (Nova Iorque: Universe, 1972), de autoria de cientistas do Massachusetts Institute of Technology (MIT), nos Estados Unidos. O livro Models of Doom: a critique of The Limits to Growth (Nova Iorque: Universe, 1973) reunia os artigos e as principais críticas da SPRU, cujo ponto central dizia respeito ao papel da mudança tecnológica na superação dos limites do crescimento. Mais tarde, novos estudos foram desenvolvidos por pesquisadores que integraram um ou outro dos grupos, atualizando os argumentos produzidos na década de 70. Ainda hoje não há consenso sobre os limites do papel da tecnologia para a superação dos problemas ambientais e, com o agravamento desses problemas, torna-se relevante aprofundar o debate, a partir das críticas já desenvolvidas nos anos 70, a fim de repensar os modelos de desenvolvimento existentes.
Marseille et ses natures: permeabilites spatiales, segmentations sociales
Authors: Claeys Cécilia , Consales Jean-Noël , Barthélémy Carole
Published: July 2014

Cet article propose une relecture de la question de la nature dans la ville à travers les paradigmes environnementaux émergeants questionnant l’ancienne dichotomie sauvage/artificiel. A partir d’une étude de cas, Marseille, ville méditerranéenne française, l’analyse interdisciplinaire articulant sociologie et géographie révèle comment les nouveaux modes de gestion de la nature urbaine et périurbaine (Parc National périurbain, trames vertes, jardins collectifs, parcs publics) interrogent les frontières spatiales entre sauvage et artificiel, tandis que les usages demeurent marqués par des formes de segmentations sociales persistantes.
Creencia y filosofía : siglos I-III d. de C
Authors: Samaranch Kirner Francisco
Published: July 2014

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Reflexiones post-foucaultianas: notas sobre la necesidad de un nuevo paradigma en filosofía política
Authors: Fernández Agis Domingo
Published: July 2014

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Ortega y Gasset y los inicios de la vanguardia artística española
Authors: Lorenzo Alquezar Rafael
Published: July 2014

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¿Es construible la inteligencia? : la elaboración de teorías en IA sigue un camino inverso respecto a las ciencias empíricas
Authors: Marquina San Miguel María Luisa
Published: July 2014

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Juegos con dados, cómputos numéricos: cómo puede ser calculado un conjunto numérico aleatorio
Authors: Alonso González Enrique
Published: July 2014

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Dialéctica y analítica: el conocimiento de los primeros principios en Aristóteles
Authors: Hernández Naranjo Ana Isabel
Published: July 2014

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Disidencia ética y desobediencia civil
Authors: Gómez Sánchez Carlos
Published: July 2014

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Hölderlin: "Solo cuando aman son buenos los mortales"
Authors: Serna Arango Julián
Published: July 2014

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¿Pensar «más allá del sujeto» como futuro de la filosofía?
Authors: Álvarez Manuel
Published: July 2014

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Sobre ciencia y brujería: el factor convencional de las creencias
Authors: Blanco Pastor Alejandro
Published: July 2014

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Sin parientes
Authors: Moreno Feliú Paz
Published: July 2014

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Heidegger y el concepto de tiempo
Authors: Adrián Escudero Jesús
Published: July 2014

En el presente artículo se analiza la conferencia que Heidegger sostuvo ante la Sociedad Teológica de Marburgo en 1924, El concepto de tiempo. El principal interés de este escrito radica en que avanza muchos de los conceptos que luego habrán de ocupar una posición central en Ser y tiempo. No en vano, diferentes estudiosos de la obra temprana de Heidegger consideran que en esta conferencia se lleva a cabo un primer desarrollo sistemático de las ideas principales del joven Heidegger y que, a la postre, preparan el camino hacia la redacción de Ser y tiempo. En el contexto de esta discusión articulamos el trabajo que aquí se presenta en dos partes: por un lado, se ofrece una breve panorámica del marco intelectual en el que se enmarca la conferencia y, por otro lado, se aborda el estudio de su estructura y contenido.
En torno a la noción del ser en Ortega: acerca de algunos interrogantes e incertidumbres que se plantean en los vectores ontológico y epistemológico de la filosofía orteguiana
Authors: García Aguilar Luis
Published: July 2014

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RESEÑA de : Abbagnano, Nicola. Dizzionario di Filosofía. Torino : Utet, 1998
Authors: Martínez Bisbal Josep
Published: July 2014

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RESEÑA de : González García; Martínez Bisbal, J. (eds.). Autobiografia de Giambattista Vico. Madrid : Siglo XXI, 1998
Authors: Martínez Francisco José
Published: July 2014

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Las “agonías” del eurocentrismo
Authors: Lomba Fuentes Joaquín
Published: July 2014

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Hacia un encuentro Oriente-Occidente
Authors: Román López María Teresa
Published: July 2014

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La situación actual del psicoanálisis
Authors: Major René
Published: July 2014

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De la melancolía liberal al “ethos” liberal: en torno a “La rebelión de las masas” de José Ortega y Gasset
Authors: Cerezo Galán Pedro
Published: July 2014

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El plural legado filosófico de Aranguren
Authors: Gómez Sánchez Carlos
Published: July 2014

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Tipos de racionalidad
Authors: Schnädelbach Herbert
Published: July 2014

Este escrito traza el esbozo de una teoría de la racionalidad que intenta analizar el concepto de racionalidad del modo más comprehensivo y completo posible. No sólo se tendrán en cuenta los más importantes contextos de aplicación de este concepto en la actualidad, sino también aquellos otros de la tradición filosófica, que en su corriente principal siempre se ha interpretado a si misma como filosofía de la razón. Por supuesto, esto sólo es posible empleando medios tipológicos. La explicación propuesta distingue entre racionalidad de fundamentación en el nivel del lenguaje objeto, racionalidad discursiva (argumentación) y racionalidad de reglas, y señala subtipos en cada uno de estos niveles. De este modo, nuestra explicación se orienta por la distinción kantiana entre razón, facultad de juzgar y entendimiento. Finalmente, el concepto de intencionalidad como condición elemental de la racionalidad establece la conexión entre la teoría de la racionlidad y la antropología filosófica. (Advertencia preliminar: Como en lo que sigue sólo intento presentar los fundamentos de una teoría, renuncio a exponer posiciones alternativas y a citar pormenorizadamente las fuentes bibliográficas. La discusión de este texto no debería referirse a si he comprendido o apreciado correctamente a otros autores, a no ser que de ello surgiese algún argumento acerca del asunto mismo de que se trata)
La epistemología a la vuelta del siglo XXI
Authors: Olivé León
Published: July 2014

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La psicología del sentido común y la teoría de la teoría: algunas reflexiones críticas
Authors: Rabossi Eduardo
Published: July 2014

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And the winner is...: algunas reflexiones que pueden llevar a una visión más ajustada de la ciencia
Authors: Pérez Sedeño Eulalia
Published: July 2014

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Ontología y nihilismo
Authors: Oñate y Zubía Teresa
Published: July 2014

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Pragmática, hermenéutica y noología: pugna de analíticas más allá de la criptometafísica
Authors: Conill Sancho Jesús
Published: July 2014

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Ética y política: moral cívica para una ciudadanía cosmopolita
Authors: Cortina Orts Adela
Published: July 2014

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El individuo ante la ética pública
Authors: Muguerza Javier
Published: July 2014

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Estudio de un caso práctico: escribir un cuadro, describir una vida
Authors: Cohn Danièle
Published: July 2014

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¿Es esto una obra de arte?: la realización de una idea estética kantiana por un desconocido Mr. Mutt
Authors: Marchán Fiz Simón
Published: July 2014

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El análisis de semejanza de las propiedades
Authors: Pagès Joan
Published: July 2014

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El escupitajo de luna o esmeralda de los filósofos: algunas notas más sobre ciencia moderna y postmoderna
Authors: Racionero Quintín
Published: July 2014

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Vico y la estrategia racionalista
Authors: Damiani Alberto Mario
Published: July 2014

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Ilustración y criticismo: acerca del sentido de la crítica de Hume a la metafísica
Authors: Egido Serrano José
Published: July 2014

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La fenomenología: una antología coordinable con la teoría de las catástrofes
Authors: Pérez Herranz Fernando M.
Published: July 2014

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En torno al aristotelismo de Galileo en el diálogo
Authors: Casas González Justiniano
Published: July 2014

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RESEÑA de : Fraijo, M. A vueltas con la religión. Estella, 1988
Authors: Abella Maeso María José
Published: July 2014

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Elementos para la enseñanza de las ciencias derivados de la obra de T. S. Kuhn
Authors: Guerrero Pino Germán
Published: July 2014

El presente escrito busca contribuir a la reflexión pedagógica y a la práctica pedagógica presentando tres estrategias para la enseñanza de las ciencias. Estas estrategias plantean en concreto: la importancia de diseñar e implementar libros de texto que, con el propósito de desarrollar una imagen de la ciencia más compleja que la lineal y acumulativa privilegiada por la enseñanza tradicional, rompan con estos cánones tradicionales de tal manera que se puedan emplear paralelamente libros de texto con diferentes enfoques; un nuevo concepto de teoría empírica en donde no se traza una jerarquía epistemológica entre leyes y aplicaciones de una teoría, sino que por el contrario se evidencia su unidad en el conocimiento de la teoría misma; pensar la enseñanza de una nueva teoría como un proceso de aprendizaje de un lenguaje y de conocimiento del mundo, en donde por lo menos se tenga en cuenta las siguientes tres propiedades de una teoría empírica: ser localmente bolista, proporcionar una taxonomía y un patrón de semejanza/diferencia. Las tres estrategas no sólo se presentan en el contexto de los trabajos de T. S. Kuhn sino que también se muestran como derivaciones de algunas de sus principales tesis filosóficas sobre la ciencia.
Construcción del lenguaje matemático: cuadros y tablas
Authors: Sanz Lerma Inés
Published: July 2014

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