bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of the mean sea level continuous record with future altimetric missions: Jason-3 vs. Sentinel-3a
Authors: Zawadzki L. , Ablain M.
Published: January 2016

Abstract. The current mean sea level (MSL) continuous record, essential to understanding the climate evolution, is computed with the altimetric measurements of the TOPEX/Poseidon mission, succeeded by Jason-1 and later Jason-2. The accurate continuity of the record is ensured by the conservation of the "historical" TOPEX orbit as well as by calibration phases between the successive missions which enable a rigorous computation of their relative biases. In order to extend the current MSL record, Jason-3 will be the natural successor of Jason-2: on the same orbit with a calibration phase. Shortly after Jason-3, another altimetric climate-oriented mission, Sentinel-3a, will be launched on a different orbit. In this paper, simulated altimetric sea level data are used to study the sensitivity of the MSL continuous record to the change of the "historical" orbit for the new Sentinel-3a orbit. By estimating the impact of the absence of calibration phase on the MSL continuous record trend accuracy at the global and regional scales and the impact of the orbit change on the long-term continuity of this MSL record, this study shows that linking Sentinel-3a data instead of Jason-3 to the MSL continuous record would not meet climate user requirements regarding the MSL trend accuracy.
Statistical Analysis of Wave Energy Resources Available for Conversion at Natural Caves of Cape-Verde Islands
Authors: Monteiro W. M. L. , Sarmento A. J. , Fernandes A. J. , Fernandes J. M.
Published: January 2016

Abstract. Using the time-series of significant wave height and the peak period between 1979 and 2009 generated by SOWFIA project, some relevant statistical information about energy content available in ocean waves in Cape-Verde is obtained. The monthly and annual time-series of the average power are analysed and the confidence intervals for their values are defined. Considering all of the 31 years of data, the results show that the most energetic month, from the average power point of view is January (23.49 kW/m) and the least energetic month is July (15.04 kW/m). In fact, the monthly average power decays from January to July and increases from July to December (21.21 kW/m). The annual average power exhibits a clear attenuation over the 31 years analysed, the reason for which is not yet clear to us. However, using the appropriate Autoregressive Integrated Moving Average (ARIMA) model it is possible to estimate that future values of the annual average power tend to oscillate around 18.2 kW/m. Through the Coefficient of Variation of Power (COVP), obtained by dividing the standard deviation of the power time-series by the average power, it is possible to conclude that the wave resource is stable, with COVP between 0.46 and 0.66. The values of the Monthly Variation Index (MVI), the maximum range of the monthly mean wave power relative to the yearly mean level, show that the resource is relatively stable, with MVI < 1.2. The present work calculates the available power input into the Natural Caves (NCs) in Cape Verde Islands, through a rigorous analysis of the wave climate that excites them. The minimum sampling size and the corresponding numbers of days of measurements per month, are also estimated.
Geopotential field anomalies and regional tectonic features – two case studies: southern Africa and Germany
Authors: Korte Monika , Mandea Mioara
Published: January 2016

Abstract. Maps of magnetic and gravity field anomalies provide information about physical properties of the Earth’s crust and upper mantle, helpful in understanding geological conditions and tectonic structures. Depending on data availability, whether from ground, airborne or from satellites, potential field anomaly maps contain information on different ranges of spatial wavelengths, roughly corresponding to sources at different depths. Focussing on magnetic data, we compare amplitudes and characteristics of anomalies from maps based on various available data and as measured at geomagnetic repeat stations. Two cases are investigated: southern Africa, characterised by geologically old cratons and strong magnetic anomalies, and the smaller region of Germany with much younger crust and weaker anomalies. Estimating lithospheric magnetic anomaly values from the ground stations time-series (repeat station crustal biases) reveals magnetospheric field contributions causing time-varying offsets of several nT in the results. Similar influences might be one source of discrepancy when merging anomaly maps from different epochs. Moreover, we take advantage of recently developed satellite potential field models and compare magnetic and gravity gradient anomalies of ~200 km resolution. Density and magnetization represent independent rock properties and thus provide complementary information on componsitional and structural changes. Comparing short and long wavelength anomalies and the correlation of rather large scale magnetic and gravity anomalies, and relating them to known lithospheric structures, we generally find a better agreement in the southern African than the German region. This probably indicates stronger concordance between near-surface and deeper structures in the former area, which can be seen to agree with a thicker lithosphere and a lower heat flux reported in the literature for the southern African region.
Hydraulic fracturing in thick shale basins: problems in identifying faults in the Bowland and Weald Basins, UK
Authors: Smythe David K.
Published: January 2016

Abstract. North American shale basins differ from their European counterparts in that the latter are one to two orders of magnitude smaller in area, but correspondingly thicker, and are cut or bounded by normal faults penetrating from the shale to the surface. There is thus an inherent risk of groundwater resource contamination via these faults during or after unconventional resource appraisal and development. US shale exploration experience cannot simply be transferred to the UK. The Bowland Basin, with 1900 m of Lower Carboniferous shale, is in the vanguard of UK shale gas development. A vertical appraisal well to test the shale by hydraulic fracturing (fracking), the first such in the UK, triggered earthquakes. Re-interpretation of the 3D seismic reflection data, and independently the well casing deformation data, both show that the well was drilled through the earthquake fault, and did not avoid it, as concluded by the exploration operator. Faulting in this thick shale is evidently difficult to recognise. The Weald Basin is a shallower Upper Jurassic unconventional oil play with stratigraphic similarities to the Bakken play of the Williston Basin, USA. Two Weald licensees have drilled, or have applied to drill, horizontal appraisal wells based on inadequate 2D seismic reflection data coverage. I show, using the data from the one horizontal well drilled to date, that one operator failed identify two small but significant through-going normal faults. The other operator portrayed a seismic line as an example of fault-free structure, but faulting had been smeared out by reprocessing. The case histories presented show that: (1) UK shale exploration to date is characterised by a low degree of technical competence, and (2) regulation, which is divided between four separate authorities, is not up to the task. If UK shale is to be exploited safely: (1) more sophisticated seismic imaging methods need to be developed and applied to both basins, to identify faults in shale with throws as small as 4–5 m, and (2) the current lax and inadequate regulatory regime must be overhauled, unified, and tightened up.
Ion's association in soil and vadose zone of Azov-Black sea region
Authors: Batukaev A. A. , Endovitsky A. P. , Andreev A. G. , Kalinichenko V. P. , Minkina T. M. , Chapligin V. A. , Dikaev Z. S. , Mandzhieva S. S. , Sushkova S. N.
Published: January 2016

Abstract. The assessment of soil and vadose zone as the drains for carbon sink, proper modelling of the effects and extremes of biogeochemical cycles in terrestrial biosphere are the key components to understand the carbon cycle, global climate system, aquatic and terrestrial systems uncertainties. Carbonate-calcium equilibrium causes saturation of solution with CaCO3, determines its material composition, migration and accumulation of salts. In solution are formed electrically neutral ion pairs СаСО3°, CaSO4°, MgCO3°, MgSO4°. Charged ion pairs CaHCO3+, MgHCO3+, NaCO3−, NaSO4−, CaOH+, MgOH+ are developed the carbonate-calcium equilibrium algorithm, mathematical model and original software to calculate the real equilibrium forms of ions and determine the nature of carbonate-calcium balance in solution. An approach conducts the quantitative assessment of real ion forms of solution in solonetz soil and vadose zone of dry steppe taking into account the ions association at high ionic strength of saline soil solution. The concentration of free and associated ion form were calculated according to analytical ion concentration in real solution. In iteration procedure were used the equations of ion material balance, a linear interpolation of equilibrium constants, a method of ionic pairs, the laws of initial concentration preservation, operating masses of equilibrium system, the concentration constants of ion pair dissociation. The coefficient of ion association γe was determined as a ratio of ions free form to analytical content of ion γe=Cass/Can. Depending on soil and vadose zone layer, concentration and composition of solution in the ionic pair's form are: 11–52% Ca2+; 22.2–54.6% Mg2+; 1.1–10.5% Na+; 3.7–23.8 HCO3−, 23.3–61.6% SO42−, up to 85.7% CO32−. The carbonate system of soil and vadose zone water solution helps to explain the evolution of salted soils, vadose and saturation zones, and landscape, improve the soil maintenance, plant nutrition and irrigation. The association of ions in soil solutions is one of the drivers, promoting transformation of solution, excessive fluxes of carbon in the soil, loss of carbon from soil through vadose zone.
Spatial variability of some soil properties in west coastal area of India having oil palm (Elaeis guineensis Jacq.) plantations
Authors: Behera Sanjib K. , Suresh K. , Rao B. N. , Mathur Ravi K. , Shukla Arvind K. , Manorama K. , Ramachandrudu K. , Harinarayana P.
Published: January 2016

Abstract. Mapping spatial variability of soil properties is the key to efficient soil resource management for sustainable crop yield in coastal areas. Therefore, the present study was conducted to assess the spatial variability of soil properties like–acidity (pH), salinity (Electrical Conductivity (EC)), organic carbon, available K, available P, exchangeable Ca2+, exchangeable Mg2+, available S and hot water soluble B in surface (0–20 cm) and subsurface (20–40 cm) soil layers of oil palm plantations in south Goa and north Goa districts of Goa situated in west coastal area of India. A total of 128 soil samples were collected from 64 oil palm plantations of Goa located at an approximate interval of 5–7 km and analyzed. Soil was acidic to neutral in reaction. Other soil properties varied widely in both the soil layers. Correlations between soil pH and exchangeable Ca2+, between soil EC and available K, between available P and available S and between exchangeable Ca2+ and exchangeable Mg2+ in both the soil layers were found to be positive and significant (P = 0.01). Geostatistical analysis revealed different spatial distribution pattern for the measured soil properties. Best fit models of measured soil properties were spherical, linear, exponential, circular and Gaussian with weak to strong spatial dependency. The results revealed that site-specific fertilizer management options needed to be adopted in the oil palm plantations of the study area owing to variability in soil properties.
Evolution of rheologically heterogeneous salt structures: a case study from the NE Netherlands
Authors: Raith A. F. , Strozyk F. , Visser J. , Urai J. L.
Published: January 2016

Abstract. The growth of salt structures is controlled by the low flow strength of evaporites and by the tectonic boundary conditions. The potassium-magnesium salts (K-Mg salts) carnallite and bischofite are prime examples of layers with much lower effective viscosity than halite: their low viscosity presents serious drilling hazards but also allows squeeze solution mining. In contrast, intrasalt anhydrite and carbonate layers (stringers) are much stronger than halite. These rheological contrasts within an evaporite body have an important control on the evolution of the internal structure of salt, but how this mechanical layering affects salt deformation at different scales is not well known. In this study, we use high-resolution 3-D seismic and well data to study the evolution of the Veendam and Slochteren salt pillows at the southern boundary of the Groningen High, northern Netherlands. Here the rock salt layers contain both the mechanically stronger Zechstein III Anhydrite-Carbonate stringer and the weaker K-Mg salts, thus we are able to assess the role of extreme rheological heterogeneities on salt structure growth. The internal structure of the two salt pillows shows areas in which the K-Mg salt-rich ZIII 1b layer is much thicker than elsewhere, in combination with a complexly ruptured and folded ZIII Anhydrite-Carbonate stringer. Thickness maps of supra-salt sediments and well data are used to infer the initial depositional architecture of the K-Mg salts and their deformation history. Results suggest that faulting and the generation of depressions on the top Zechstein surface above a Rotliegend graben caused the local accumulation of bittern brines and precipitation of thick K-Mg salts. During the first phase of salt flow and withdrawal from the Veendam area, under the influence of differential loading by Buntsandstein sediments, the ZIII stringer was boudinaged while the lens of Mg salts remained relatively undeformed. This was followed by a convergence stage, when the K-Mg salt-rich layers were deformed within the inflating salt pillows. This deformation was strongly disharmonic and strongly influenced by folding of the underlying, ruptured ZIII stringer, leading to thickening and internal deformation of the K-Mg salt layers.
Soil archives of a Fluvisol: subsurface analysis and soil history of the medieval city centre of Vlaardingen, the Netherlands – an integral approach
Authors: Kluiving S. J. , de Ridder T. , van Dasselaar M. , Roozen S. , Prins M. A.
Published: January 2016

Abstract. In Medieval times the city of Vlaardingen (the Netherlands) was strategically located on the confluence of three rivers, the Meuse, the Merwede and the Vlaarding. A church of early 8th century was already located here. In a short period of time Vlaardingen developed into an international trading place, the most important place in the former county of Holland. Starting from the 11th century the river Meuse threatened to flood the settlement. These floods have been registered in the archives of the fluvisol and were recognised in a multidisciplinary sedimentary analysis of these archives. To secure the future of this vulnerable soil archive currently an extensive interdisciplinary research (76 mechanical drill holes, grain size analysis (GSA), thermo-gravimetric analysis (TGA), archaeological remains, soil analysis, dating methods, micromorphology, and microfauna has started in 2011 to gain knowledge on the sedimentological and pedological subsurface of the mound as well as on the well-preserved nature of the archaeological evidence. Pedogenic features are recorded with soil descriptive, micromorphological and geochemical (XRF) analysis. The soil sequence of 5 meters thickness exhibits a complex mix of "natural" as well as "anthropogenic layering" and initial soil formation that enables to make a distinction for relatively stable periods between periods with active sedimentation. In this paper the results of this large-scale project are demonstrated in a number of cross-sections with interrelated geological, pedological and archaeological stratification. Distinction between natural and anthropogenic layering is made on the occurrence of chemical elements phosphor and potassium. A series of four stratigraphic/sedimentary units record the period before and after the flooding disaster. Given the many archaeological remnants and features present in the lower units, we assume that the medieval landscape was drowned while it was inhabited in the 12th century AD. After a final drowning phase in the 13th century, as a reaction to it, inhabitants started to raise the surface.
Enzymatic biofilm detachment causes a loss of aggregate stability in a sandy soil
Authors: Büks F. , Kaupenjohann M.
Published: January 2016

Abstract. The stability of soil aggregates against shear and compressive forces as well as water caused dispersion is an integral marker of soil quality. High stability results in less soil compactibility and erodibility, enhanced water retention, a dynamic water transport and aeration regime, increased rooting depth and protection of soil organic matter (SOM) against microbial degradation. For decades the importance of biofilm extracellular polymeric substances (EPS) regarding aggregate stability has been canonical because of its distribution, geometric structure and ability to link primary particles. However, experimental proof is still missing. This lack is mainly due to methodological reasons. Thus, the objective of this work is to develop a method of enzymatic biofilm detachment for studying the effects of EPS on soil aggregate stability. The method combines an enzymatic pre-treatment with different activities of α-glucosidase, β-galactosidase, DNAse and lipase, which preserves aggregate structure, with a subsequent sequential ultrasonic treatment for disaggregation and density-fractioning. Soil organic carbon (SOC) releases of treated samples were compared to an enzyme-free control. To test the effectivity of biofilm detachment the ratio of bacterial DNA from sessile and suspended cells after enzymatic treatment was measured by quantitative real-time PCR. Although the enzyme treatment was not sufficient for total biofilm removal, our results confirm, that EPS stabilizes soil aggregates predominantly by a strong intra-aggregate fixation, and enzymatic biofilm digestion caused a shift of occluded particulate organic matter (POM) to more fragile binding patterns. This suggests that an effect of agricultural practices on soil microbial populations could influence aggregate stability and thereby soil quality.
Soil bacterial community and functional shifts in response to thermal insulation in moist acidic tundra of Northern Alaska
Authors: Ricketts M. P. , Poretsky R. S. , Welker J. M. , Gonzalez-Meler M. A.
Published: January 2016

Abstract. Soil microbial communities play a central role in the cycling of carbon (C) in Arctic tundra ecosystems, which contain a large portion of the global C pool. Climate change predictions for Arctic regions include increased temperature and precipitation (i.e. more or less snow), resulting in increased winter soil insulation, increased soil temperature and moisture, and shifting plant community composition. We utilized an 18-year snowfence study site designed to examine the effects of increased winter precipitation on Arctic tundra soil bacterial communities within the context of ecosystem response to climate change. Soil was collected from three pre-established treatment zones representing varying degrees of snow accumulation (DEEP, INT, LOW), soil physical properties (temperature, moisture, active layer thaw depth) were measured, and samples were analysed for C content, nitrogen (N) content, and pH. DNA was extracted and the 16S rRNA gene was sequenced to reveal phylogenetic community differences between samples and determine how soil bacterial communities might respond (structurally and functionally) to changes in winter precipitation and soil chemistry. We analysed relative abundance changes of the six most abundant phyla and found four (Acidobacteria, Actinobacteria, Verrucomicrobia, and Chloroflexi) responded to deepened snow. All six phyla correlated with at least one of the soil chemical properties (%C, %N, C:N, pH), however a single predictor was not identified suggesting that each bacterial phylum responds differently to soil characteristics. Overall bacterial community structure (beta diversity) was found to be associated with snow accumulation treatment and all soil chemical properties. Bacterial functional potential was inferred using ancestral state reconstruction to approximate functional gene abundance, revealing a decreased abundance of genes required for soil organic matter (SOM) decomposition in the organic horizon of the deep snow accumulation zones. These results suggest that predicted climate change scenarios may result in altered soil bacterial community structure and function, and indicate either a reduction in decomposition potential that may limit C loss from the system, or alleviated temperature limitations on enzymatic efficiency, or both. The fate of stored C in Arctic soils ultimately depends on the balance between these mechanisms.
Switchgrass ecotypes alter microbial contribution to deep soil C
Authors: Roosendaal Damaris , Stewart Catherine E. , Denef Karolien , Follett Ronald F. , Pruessner Elizabeth , Comas Louise H. , Varvel Gary E. , Saathoff Aaron , Palmer Nathan , Sarath Gautam , Jin Virginia L. , Schmer Marty , Soundararajan Madhavan
Published: January 2016

Abstract. Switchgrass (Panicum virgatum L.) is a C4, perennial grass that is being developed as a bioenergy crop for the United States. While aboveground biomass production is well documented for switchgrass ecotypes (lowland, upland), little is known about the impact of plant belowground productivity on microbial communities down deep in the soil profiles. Differences in root biomass and rooting characteristics of switchgrass ecotypes could lead to distinct differences in belowground microbial biomass and microbial community composition. We quantified root biomass and root architecture and the associated microbial abundance, composition and rhizodeposit C uptake for two switchgrass cultivars using stable isotope probing of microbial phospholipid fatty acids (PLFA) after 13CO2 pulse-chase labeling. Kanlow, a lowland cultivar with thicker roots, had greater plant biomass above- and belowground, greater root mass density, and lower specific root length compared to Summer, an upland cultivar with finer root architecture. The relative abundance of bacterial biomarkers dominated microbial PLFA profiles for both Kanlow and Summer soils (55.4% and 53.5%, respectively), with differences attributable to a greater relative abundance of gram-negative bacteria in Kanlow soils (18.1%) compared to Summer soils (16.3%). The two ecotypes also had distinctly different microbial communities process rhizode posit C; greater relative atom % 13C excess in gram-negative bacteria (44.1 ± 2.3%) under the thicker roots of Kanlow and greater relative atom % 13C excess saprotrophic fungi under the thinner roots of Summer (48.5 ± 2.2%). For bioenergy production systems, variation between switchgrass ecotypes could alter microbial communities and impact C sequestration and storage as well as potentially other belowground processes.
Utilisation of CryoSat-2 SAR altimeter in operational ice charting
Authors: Rinne E. , Similä M.
Published: January 2016

Abstract. We present methods to utilise CryoSat-2 (CS-2) synthetic aperture radar (SAR) mode data in operational ice charting. We compare CS-2 data qualitatively to SAR mosaics over the Barents and Kara seas. Furthermore, we compare the CS-2 to archived operational ice charts. We present distributions of four CS-2 waveform parameters for different ice types as presented in the ice charts. We go on to present an automatic classification method for CS-2 data which, after training with operational ice charts, is capable of determining open ocean from ice with a hit rate of  >  90 %. The training data are dynamically updated every 5 days using the most recent 15 days of CS-2 data and operative ice charts. This helps the adaption of the classifier to the evolving ice/snow conditions throughout winter. The classifier is also capable of detecting three different ice classes (thin and thick first-year ice as well as old ice) with success rates good enough for the output to be usable to support operational ice charting. Finally, we present a near-real-time CS-2 product just plotting the waveform characteristics and conclude that even such a simple product is usable for some of the needs of ice charting.
Estimating supraglacial lake depth in West Greenland using Landsat 8 and comparison with other multispectral methods
Authors: Pope A. , Scambos T. A. , Moussavi M. , Tedesco M. , Willis M. , Shean D. , Grigsby S.
Published: January 2016

Abstract. Liquid water stored on the surface of ice sheets and glaciers impacts surface mass balance, ice dynamics, and heat transport. Multispectral remote sensing can be used to detect supraglacial lakes and estimate their depth and area. In this study, we use in situ spectral and bathymetric data to assess lake depth retrieval using the recently launched Landsat 8 Operational Land Imager (OLI). We also extend our analysis to other multispectral sensors to evaluate their performance with similar methods. Digital elevation models derived from WorldView stereo imagery (pre-lake filling and post-drainage) are used to validate spectrally derived depths, combined with a lake edge determination from imagery. The optimal supraglacial lake depth retrieval is a physically based single-band model applied to two OLI bands independently (red and panchromatic) that are then averaged together. When OLI- and WorldView-derived depths are differenced, they yield a mean and standard deviation of 0.0 ± 1.6 m. This method is then applied to OLI data for the Sermeq Kujalleq (Jakobshavn Isbræ) region of Greenland to study the spatial and intra-seasonal variability of supraglacial lakes during summer 2014. We also give coefficients for estimating supraglacial lake depth using a similar method with other multispectral sensors.
Topographic and vegetation effects on snow accumulation in the southern Sierra Nevada: a statistical summary from lidar data
Authors: Zheng Z. , Kirchner P. B. , Bales R. C.
Published: January 2016

Abstract. Airborne light detection and ranging (lidar) measurements carried out in the southern Sierra Nevada in 2010 in the snow-free and peak-snow-accumulation periods were analyzed for topographic and vegetation effects on snow accumulation. Point-cloud data were processed from four primarily mixed-conifer forest sites covering the main snow-accumulation zone, with a total surveyed area of over 106 km2. The percentage of pixels with at least one snow-depth measurement was observed to increase from 65–90 to 99 % as the sampling resolution of the lidar point cloud was increased from 1 to 5 m. However, a coarser resolution risks undersampling the under-canopy snow relative to snow in open areas and was estimated to result in at least a 10 cm overestimate of snow depth over the main snow-accumulation region between 2000 and 3000 m, where 28 % of the area had no measurements. Analysis of the 1 m gridded data showed consistent patterns across the four sites, dominated by orographic effects on precipitation. Elevation explained 43 % of snow-depth variability, with slope, aspect and canopy penetration fraction explaining another 14 % over the elevation range of 1500–3300 m. The relative importance of the four variables varied with elevation and canopy cover, but all were statistically significant over the area studied. The difference between mean snow depth in open versus under-canopy areas increased with elevation in the rain–snow transition zone (1500–1800 m) and was about 35 ± 10 cm above 1800 m. Lidar has the potential to transform estimation of snow depth across mountain basins, and including local canopy effects is both feasible and important for accurate assessments.
Trends in sea-ice variability on the way to an ice-free Arctic
Authors: Bathiany S. , van der Bolt B. , Williamson M. S. , Lenton T. M. , Scheffer M. , van Nes E. , Notz D.
Published: January 2016

Abstract. It has been widely debated whether Arctic sea-ice loss can reach a tipping point, beyond which a large sea-ice area disappears abruptly. An important argument for this scenario is the destabilising role of the ice-albedo feedback. The theory of dynamical systems predicts a "slowing down" when a system destabilises towards a tipping point. In simple stochastic systems this can result in increasing variance and autocorrelation, potentially yielding an early warning of an abrupt change. Here we aim to establish whether the loss of Arctic sea ice would follow these conceptual predictions, an d which trends in sea ice variability can be expected from pre-industrial conditions toward an Arctic that is ice-free during the whole year. To this end, we apply a model hierarchy consisting of two box models and one comprehensive Earth system model. We find a consistent and robust decrease of the ice volume's annual relaxation time before summer ice is lost because thinner ice can adjust more quickly to perturbations. Thereafter, the relaxation time increases, mainly because the system becomes dominated by the ocean water's large heat capacity when the ice-free season becomes longer. Both trends carry over to the autocorrelation of sea ice thickness in time series. Also accounting for the geometric effect of increasing open-water formation efficiency for thinning ice, we obtain an increasing variability in sea-ice area fraction, but a decreasing variability in sea-ice thickness. These changes are robust to the nature and origin of climate variability in the models and hardly depend on the balance of feed backs. Therefore, characteristic trends can be expected in the future. As these trends are not specific to the existence of abrupt ice loss, the prospects for early warnings seem very limited. This result also has implications for statistical indicators in other systems whose effective "mass" changes over time, affecting the trend of their relaxation time. However, the robust relation between state and variability would allow an estimate of sea-ice variability from only short observations. This could help one to estimate the likelihood and persistence of extreme events in the future.
Estimation of superficial snow specific surface area from spectral albedo time-series at Dome C, Antarctica
Authors: Picard G. , Libois Q. , Arnaud L. , Vérin G. , Dumont M.
Published: January 2016

Abstract. Abstract. Spectral albedo of the snow surface in the visible/near-infrared range has been measured for 3 years by an automatic spectral radiometer installed at Dome C (75°S, 123°E) in Antarctica in order to retrieve speciﬁc surface area (SSA) of superﬁcial snow. This study focuses on the uncertainties of the SSA retrieval due to the instrument deﬁciencies and issues related to data processing. We ﬁnd that when the solar zenith angle is high, the main source of error is the imperfect angular response of the light collectors. This imperfection introduces a small spurious wavelength-dependent trend in the albedo spectra which greatly affects the SSA retrieval. By modeling this effect, we show that for typical snow and illumination conditions encountered at Dome C, retrieving SSA with an accuracy better than 15% (our target), requires the slope of this trend not to exceed 2% between 400 and 1100 nm. Such a small slope can be achieved only by i) careful design of the collectors, ii) an ad hoc correction of the spectra using the actual measured angular response of the collectors, and iii) for solar zenith angles less than 75°. The comparison of the retrieved SSA with independent measurements made with an optical device operating at 1310 nm conﬁrms the presence of a sharp and recurrent vertical gradient of SSA in the uppermost centimeter at Dome C, which challenges the assessment of the absolute accuracy from independent measurements. Nevertheless, with three-fold variations of SSA during the summer seasons, we conclude that the retrieved SSA is accurate enough to provide a detailed picture of the October-March evolution of the surface snow at Dome C.
Inversion of geothermal heat flux in a thermomechanically coupled nonlinear Stokes ice sheet model
Authors: Zhu Hongyu , Petra Noemi , Stadler Georg , Isaac Tobin , Hughes Thomas J. R. , Ghattas Omar
Published: January 2016

Abstract. We address the inverse problem of inferring the basal geothermal heat ﬂux from surface velocity observations using an instantaneous thermomechanically coupled nonlinear Stokes ice ﬂow model. This is a challenging inverse problem since the map from basal heat ﬂux to surface velocity observables is indirect: the heat ﬂux is a boundary condition for the thermal advection-diffusion equation, which couples to the nonlinear Stokes ice ﬂow equations, which then determine the surface ice ﬂow velocity. This multiphysics inverse problem is formulated as a nonlinear least-squares optimization problem with a cost functional that includes the data misﬁt between surface velocity observations and model predictions. A Tikhonov regularization term is added to render the problem well-posed. We derive adjoint-based gradient and Hessian expressions for the resulting PDE-constrained optimization problem and propose an inexact Newton method for its solution. As a consequence of the Petrov-Galerkin discretization of the energy equation, we show that discretization and differentiation do not commute; that is, the order in which we discretize the cost functional and differentiate it affects the correctness of the gradient. Using two and three-dimensional model problems, we study the prospects for and limitations of the inference of the geothermal heat ﬂux ﬁeld from surface velocity observations. The results show that the reconstruction improves as the noise level in the observations decreases, and that small wavelength variations in the geothermal heat ﬂux are difﬁcult to recover. We analyze the ill-posedness of the inverse problem as a function of the number of observations by examining the spectrum of the Hessian of the cost functional. Motivated by the popularity of operator-split or staggered solvers for forward multiphysics problems — i.e., those that drop two-way coupling terms to yield a one-way coupled forward Jacobian — we study the effect on the inversion of a one-way coupling of the adjoint energy and Stokes equations. We show that taking such a one-way coupled approach for the adjoint equations can lead to an incorrect gradient and premature termination of optimization iterations due to loss of a descent direction stemming from inconsistency of the gradient with the contours of the cost functional. Nevertheless, one may still obtain a reasonable approximate inverse solution particularly if important features of the reconstructed solution emerge early in optimization iterations, before the premature termination.
Monitoring long-term changes of glacial seismic activity with continuous seismological observations: a case study from Spitsbergen
Authors: Gajek W. , Trojanowski J. , Malinowski M.
Published: January 2016

Abstract. Changes in the global temperature balance have proved to have a major impact on the cryosphere and therefore retreating glaciers are the symbol of the warming climate. Long-term measurements of geophysical parameters provide the insight into the dynamics of those processes over many years. Here we explore the possibility of using data recorded by permanent seismological stations to monitor glacial seismic activity. Our study focuses on year-to-year changes in seismicity of the Hansbreen glacier (southern Spitsbergen). We have processed 7-year-long continuous seismological data recorded by a broadband station located in the fjord of Hornsund, obtaining seismicity distribution between 2008 and 2014. To distinguish between glacier- and non-glacier-origin events with the data from only one seismic station in the area, we developed a new fuzzy logic algorithm based on the seismic signal frequency and the energy flow analysis. Our research has revealed that the number of detected glacier-origin events over the last two years has doubled. We also observed that the annual events distribution correlates well with the temperature and precipitation data. In order to further support our observations, we have analysed 5-year-long seismological data recorded by a broadband station located in Ny-Ålesund (western Spitsbergen). Distribution of glacier-origin tremors detected in the vicinity of the Kronebreen glacier shows a steady increase from year to year, however not as significant as for the Hornsund dataset.
An ice-sheet wide framework for englacial attenuation and basal reflection from ice penetrating radar data
Authors: Jordan T. M. , Bamber J. L. , Williams C. N. , Paden J. D. , Siegert M. J. , Huybrechts P. , Gagliardini O. , Gillet-Chaulet F.
Published: January 2016

Abstract. Radar-inference of the bulk properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. On the scale of an ice-sheet, unambiguous determination of basal reflection is primarily limited by uncertainty in the englacial attenuation of the radio wave, which is an exponential function of temperature. Most existing radar algorithms assume stationarity in the attenuation rate, which is not feasible at an ice-sheet wide scale. Here we introduce a new framework for deriving englaical attenuation and basal reflection, and, to demonstrate its efficacy, we apply it to the Greenland Ice-Sheet. A central feature is the use of a prior Arrhenius temperature model to estimate the spatial variation in englaical attenuation as a first guess input for the radar algorithm. We demonstrate regions of solution convergence for two input temperature fields, and for independently analysed field campaigns. The coverage achieved is a trade-off with uncertainty and we propose that the algorithm can be "tuned" for discrimination of basal melt (attenuation loss uncertainty ∼ 5 dB). This is supported by our physically realistic (∼ 20 dB) range for the basal reflection coefficient. Finally, we show that the attenuation solution can be used to predict the temperature bias of thermomechanical ice-sheet models.
The Contribution of Information Engineering for Innovation Funding Source Obtainment
Authors: Canteri Taina C. , Frederico Guilherme F. , Mendes Ricardo , Freitas Maria C. D. , Santos Adriana P. L.
Published: January 2016

Continued innovation in products, processes, services, technology and on the company management, is essential to maintaining and achieve more competitiveness in organizations. To execute innovation projects, many companies seek external financial resources through development agencies. Taking into consideration few theoretical approaches on this topic, the Information Engineering presents itself as an element that can contribute for this process. Therefore, this study aims to find out how the information engineering can support and improve the process of funds obtainment to innovation purposes in organizations. This is an exploratory study through a systematic literature review method, which addresses three main steps: planning, processing and divulgation. The results show that the ability to manage information has a positive and direct influence on the performance of organizational innovation. Therefore, it is possible to realize that as the more information is structured and implemented more are the chances of successful in the innovation processes including funding source obtainment.
Challenges and Opportunities for the Textile Industry in Ghana: A Study of the Adinkra Textile Sub-Sector
Authors: Aboagyewaa-Ntiri Josephine , Mintah Kwabena
Published: January 2016

The purpose of the study is to examine the challenges facing the Ghanaian textile industry with emphasis on the Adinkra textile cloth printing sub sector in Ghana, as well as opportunities for improving the industry. The sub sector is distinct and has different dynamics from other sub sectors of the broader textile industry. The study informs policy makers and private sector on the factors resulting in the decline of the Adinkra textile sub sector and the need to sustain the sub sector of the textiles industry due to its heritage importance and contribution to the economy. It also examines potential business opportunities for local and international firms to invest in the textile sub market for expansion and profitability. An empirical research design with mixed-methods approach was used in this study. A qualitative approach (semi-structured interviews) was used to collect the data, coded and analysed using standard NVivo software which generated quantitative outcomes for descriptive statistical analysis. Qualitative approach was also used to interpret the findings of the study. The results indicated that, factors such as lack of access to capital, outmoded forms of technology, issues with supply chain and nature of the dyes for printing the textile cloths are primarily responsible for the declining state of the sub sector. The implications of the challenges and the declining state of the sub sector are discussed and solutions proffered to solve the challenges.
Reviewer Acknowledgements for International Business Research, Vol. 9, No. 2
Authors: Duran Kevin
Published: January 2016

International Business Research wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal are greatly appreciated.

International Business Research is recruiting reviewers for the journal. If you are interested in becoming a reviewer, we welcome you to join us. Please find the application form and details at http://www.ccsenet.org/reviewer and e-mail the completed application form to ibr@ccsenet.org.
Enhancing Entrepreneurial Intention and Innovativeness of University Students: The Mediating Role of Entrepreneurial Alertness
Authors: Gozukara Izlem , Colakoglu Nurdan
Published: January 2016

Entrepreneurship is a process of value creation consisting of committing time and effort, considering financial, social and other risks, resulting financial gain. The initial step of entrepreneurship is to recognize opportunities, which refers to a mechanism of intention. Empirical studies have provided evidence that entrepreneurial behavior is best predicted by intention. Intention, in turn, is associated with certain personality traits and attributes. This study aims to investigate the mediating effect of entrepreneurial alertness on the relationship between innovativeness and entrepreneurial intention of Turkish university students. The results of the study demonstrated that innovativeness has a positive effect on entrepreneurial intention, and entrepreneurial alertness fully mediates the relationship between innovativeness and entrepreneurial alertness. The present paper suggests that higher education institutions should focus on modifying personal attitudes of college students through entrepreneurship education and business incubation programs in order to foster enterprise creation and thereby economic development.
Work-Life Balance: The Good and the Bad of Boundary Management
Authors: C. Leduc , N. Houlfort , S. Bourdeau
Published: January 2016

Work-life balance is an important issue in today’s world and the different strategies used by people to manage their work and their personal life can have a great impact. Two studies were conducted (study 1: n = 117; study 2: n = 293) to examine how boundary segmentation preferences (studies 1 & 2) and boundary integration strategies (study 2) affect work-family conflict and enrichment. Results from structural equation modeling partly confirmed the hypothetical model in both studies. Study 1 showed that work-home segmentation preference negatively predicted work-family enrichment, while home-work segmentation preference negatively predicted family-work enrichment. Study 2 provided similar results, as it showed that work-home segmentation preference negatively predicted work-family enrichment. It also showed that work-home segmentation preference positively predicted work-family conflict and home-work segmentation preference positively predicted work-family enrichment, while work-life integration strategy positively predicted work-family conflict, family-work conflict, work-family enrichment and family-work enrichment. No significant relationship was found between life-work integration strategy and any of the dependent variables. Findings from these studies highlight the importance of using appropriate boundary management strategies in order to promote a better work-life balance. They also enhance current knowledge related to boundary management and work-life balance by examining relationships with work-family enrichment.
The New Market Transformation Needed for Commercial Building Energy Efficiency
Authors: Patrick Valerie , Billhymer Leslie A. , Shephard William
Published: January 2016

The U.S. Department of Energy [DOE] established the Consortium for Building Energy Innovation [CBEI] to address commercial building energy efficiency as an innovation cluster, where the regional market context (Note 1) guides the research agenda for market transformation (Porter, 2001). CBEI develops content to support Advanced Energy Retrofits (AERs), a retrofit which results in 50% or greater reduction in building energy use, in small- and medium- sized commercial buildings (less than 250 000 ft2). The challenge is collecting input for a market with many stakeholders so that a strategy emerges to implement AERs. This research applies systems and complexity theories to develop a strategy to promote the emergence of AERs in this market incorporating multiple stakeholder perspectives (Note 2).
A Review and Discussion on Modeling and Assessing Agricultural Best Management Practices under Global Climate Change
Authors: Liu Yongbo , Yang Wanhong , Qin Chengzhi , Zhu Axing
Published: January 2016

Understanding the impacts of global climate change on the spatiotemporal pattern of hydrologic cycle and water resources is of major importance in highly developed watersheds all over the world. These impacts are strongly dependent on related changes in intensity and frequency of extreme climate events. Implementation of Best Management Practices (BMPs) and policy approaches at watershed and regional scales is essential for mitigating their negative impacts on soil and water conservation, and sustainable economic development. However, the uncertainty of BMP effectiveness including increasing variability of future water supply and changing magnitudes of nonpoint source pollution has to be accounted for in watershed planning and management. This paper provides a review and discussion on the impacts of global climate change on BMP’s hydrologic performance, the current progress on hydrologic assessment of BMPs, as well as the existing problems and countermeasures. Research challenges and opportunities in the field of hydrologic assessment of BMPs under global climate change are also discussed in this paper.