bluuebunny/crossref_metadata_2025_split huggingface dataset:
Depth of Origin of the Peak (Inner) Ring in Lunar Impact Basins
Authors: Miljković Katarina , Lemelin Myriam , Lucey Paul G. 
Published: October 2017

AbstractNumerical modeling of the peak‐ring basin formation showed that the peak‐ring forms from the material that is part of the central uplift outwardly thrust over the inwardly collapsing transient crater rim. Simulations of the lunar basin formation showed that the peak or inner ring in peak ring or multiring basins, respectively, is composed of the overturned crust and deep‐seated material, possibly from the upper mantle. Numerical impact simulations were used to trace the depth of origin of material exposed within the peak (or inner) ring. We estimate the scaling trends between basin size and the depth of origin of material exposed within the ring. We also report on the likely crust, mantle, and projectile abundances exposed within the ring. Quantifying the excavation depths during the formation of the peak or inner ring provides a step toward understanding the lunar crust and mantle stratigraphy.
A Hydrometeorological Perspective on the Karakoram Anomaly Using Unique Valley‐Based Synoptic Weather Observations
Authors: Bashir Furrukh , Zeng Xubin , Gupta Hoshin , Hazenberg Pieter 
Published: October 2017

AbstractGlaciers in the eastern Hindukush, western Karakoram, and northwestern Himalayan mountain ranges of Northern Pakistan are not responding to global warming in the same manner as their counterparts elsewhere. Their retreat rates are less than the global average, and some are either stable or growing. Various investigations have questioned the role of climatic factors in regard to this anomalous behavior, widely referred to as “The Karakoram Anomaly.” Here, for the first time, we present a hydrometeorological perspective based on five decades of synoptic weather observations collected by the meteorological network of Pakistan. Analysis of this unique data set indicates that increased regional scale humidity, cloud cover, and precipitation, along with decreased net radiation, near‐surface wind speed, potential evapotranspiration, and river flow, especially during the summer season, represent a substantial change in the energy, mass, and momentum fluxes that are facilitating the establishment of the Karakoram anomaly.
Conversion of Wet Glass to Melt at Lower Seismogenic Zone Conditions: Implications for Pseudotachylyte Creep
Authors: Proctor B. P. , Lockner D. A. , Lowenstern J. B. , Beeler N. M. 
Published: October 2017

AbstractCoseismic frictional melting and the production of quenched glass called pseudotachylyte is a recurring process during earthquakes. To investigate how glassy materials affect the postseismic strength and stability of faults, obsidian gouges were sheared under dry and wet conditions from 200°C to 300°C at ~150 MPa effective normal stress. Dry glass exhibited a brittle rheology at all conditions tested, exhibiting friction values and microstructures consistent with siliciclastic materials. Likewise, wet glass at 200°C exhibited a brittle rheology. In contrast, wet gouges at 300°C transitioned from brittle sliding to linear‐viscous (Newtonian) flow at strain rates <3 × 10−4 s−1, indicating melt‐like behavior. The viscosity ranged from 2 × 1011 to 7.8 × 1011 Pa‐s. Microstructures show that viscous gouges were fully welded with rod‐shaped microlites rotated into the flow direction. Fourier transform infrared spectroscopy along with electron backscatter imaging demonstrate that hydration of the glass by diffusion of pore water was the dominant process reducing the viscosity and promoting viscous flow. As much as 5 wt % water diffused into the glass. These results may provide insight into postseismic‐slip behaviors and challenge some interpretations of fault kinematics based on studies assuming that pseudotachylyte formation and flow is solely coseismic.
Ice and Snow Thickness Variability and Change in the High Arctic Ocean Observed by In Situ Measurements
Authors: Haas Christian , Beckers Justin , King Josh , Silis Arvids , Stroeve Julienne , Wilkinson Jeremy , Notenboom Bernice , Schweiger Axel , Hendricks Stefan 
Published: October 2017

AbstractIn April 2017, we collected unique, extensive in situ data of sea ice and snow thickness. At 10 sampling sites, located under a CryoSat‐2 overpass, between Ellesmere Island and 87.1°N mean and modal total ice thicknesses ranged between 2 to 3.4 m and 1.8 to 2.9 m, respectively. Coincident snow thicknesses ranged between 0.3 to 0.47 m (mean) and 0.1 to 0.5 m (mode). The profile spanned the complete multiyear ice zone in the Lincoln Sea, into the first‐year ice zone farther north. Complementary snow thickness measurements near the North Pole showed a mean thickness of 0.31 m. Compared with scarce measurements from other years, multiyear ice was up to 0.75 m thinner than in 2004, but not significantly different from 2011 and 2014. We found excellent agreement with a commonly used snow climatology and with published long‐term ice thinning rates. There was reasonable agreement with CryoSat‐2 thickness retrievals.
Differential Radiative Heating Drives Tropical Atmospheric Circulation Weakening
Authors: Xia Yan , Huang Yi 
Published: October 2017

AbstractThe tropical atmospheric circulation is projected to weaken during global warming, although the mechanisms that cause the weakening remain to be elucidated. We hypothesize that the weakening is related to the inhomogeneous distribution of the radiative forcing and feedback, which heats the tropical atmosphere in the ascending and subsiding regions differentially and thus requires the circulation to weaken due to energetic constraints. We test this hypothesis in a series of numerical experiments using a fully coupled general circulation model (GCM), in which the radiative forcing distribution is controlled using a novel method. The results affirm the effect of inhomogeneous forcing on the tropical circulation weakening, and this effect is greatly amplified by radiative feedback, especially that of clouds. In addition, we find that differential heating explains the intermodel differences in tropical circulation response to CO2 forcing in the GCM ensemble of the Climate Model Intercomparison Project.
A New Mechanism for Upper Crustal Fluid Flow Driven by Solitary Porosity Waves in Rigid Reactive Media?
Authors: Chakraborty Sumit 
Published: October 2017

AbstractThe equations governing the interaction of viscous deformation with porous flow of fluids give rise to wave‐like solutions. Such solutions have been explored in the context of melt and fluid flow in the mantle and crust at high temperatures, where ductile behavior occurs. Now it has been shown that the coupling of the kinetics of chemical reactions with fluid flow may give rise to similar solutions. This opens intriguing new possibilities. Porosity waves may arise in low‐temperature regimes, and may become more accessible to observation, or they may remain mathematical curiosities because other modes of transport dominate in such settings. A number of possibilities, questions, and future courses of research have been opened up by Omlin et al. (2017, https://doi.org.10.1002/2017GL074293).
Reply to Comment on “A simple model for regolith formation by chemical weathering” by Braun et al. Contradictory concentrations and a tale of two velocities by Harman et al.
Authors: Braun Jean , Guillocheau François , Robin Cecile 
Published: October 2017

AbstractThe apparent contradiction evidenced by Harman et al. is, in our opinion, a consequence of them assuming that the concentration of the solute is at equilibrium value Ceq, an assumption that is not part of our model. We take this opportunity to more clearly demonstrate that under the assumptions the concentration of the solute is not at equilibrium, the rate of dissolution and consequently the rate of propagation of the weathering front are, to first order, proportional to the velocity of the fluid parallel to the weathering front and thus to the slope of the water table. The results we derive from this assumption are therefore valid.
Analysis of Grazing GNSS Reflections Observed at the Zeppelin Mountain Station, Spitsbergen
Authors: Peraza L. , Semmling M. , Falck C. , Pavlova O. , Gerland S. , Wickert J. 
Published: October 2017

AbstractA reflectometry station has been set up in 2013 near Ny‐Ålesund, Svalbard, at 78.9082°N, 11.9031°E. The main goal of the setup is to resolve the spatial and temporal variations in snow and ice cover, based on reflection power observations at grazing elevations. In this study, we develop a method to map the recorded signal power to the main reflection contributions while also discussing the spatial characteristics of the observations. A spectral analysis resolving differential Doppler between direct and reflected signals is presented to identify reflection contributions for a complete year (2014). Strong water reflections are identified with power ratios higher than 70 dB/Hz and constant Doppler shifts of 0.5–0.6 Hz for all elevations. Contributions with ratios higher than 40 dB/Hz can be related to specular land or glacier reflections, for which Doppler shift usually increases with the elevation angle and the distance between reflection point and receiver. Reflections nearby, around 3–5 km, show differential Doppler of 0.4–0.5 Hz, while for reflections farther than 16 km away, Doppler shift is usually larger than 0.8 Hz. Azimuth variations cause cross‐track drift of up to 4° during the observation year. Topography‐induced shadowing of very low lying satellites limits the extent of the monitoring area. However, the amount of satellites tracked daily, up to 30, allows the reflectometry station to constantly record reflections over areas with thick snow cover and glaciers. This offers the possibility to compare the derived reflected power with local meteorological data to resolve snow and ice variations on the area.
Faraday Rotation of Automatic Dependent Surveillance‐Broadcast (ADS‐B) Signals as a Method of Ionospheric Characterization
Authors: Cushley A. C. , Kabin K. , Noël J.‐M. 
Published: October 2017

AbstractRadio waves propagating through plasma in the Earth's ambient magnetic field experience Faraday rotation; the plane of the electric field of a linearly polarized wave changes as a function of the distance travelled through a plasma. Linearly polarized radio waves at 1090 MHz frequency are emitted by Automatic Dependent Surveillance Broadcast (ADS‐B) devices that are installed on most commercial aircraft. These radio waves can be detected by satellites in low Earth orbits, and the change of the polarization angle caused by propagation through the terrestrial ionosphere can be measured. In this manuscript we discuss how these measurements can be used to characterize the ionospheric conditions. In the present study, we compute the amount of Faraday rotation from a prescribed total electron content value and two of the profile parameters of the NeQuick ionospheric model.
Coupled Long‐Term Simulation of Reach‐Scale Water and Heat Fluxes Across the River‐Groundwater Interface for Retrieving Hyporheic Residence Times and Temperature Dynamics
Authors: Munz Matthias , Oswald Sascha E. , Schmidt Christian 
Published: October 2017

AbstractFlow patterns in conjunction with seasonal and diurnal temperature variations control ecological and biogeochemical conditions in hyporheic sediments. In particular, hyporheic temperatures have a great impact on many temperature‐sensitive microbial processes. In this study, we used 3‐D coupled water flow and heat transport simulations applying the HydroGeoSphere code in combination with high‐resolution observations of hydraulic heads and temperatures to quantify reach‐scale water and heat flux across the river‐groundwater interface and hyporheic temperature dynamics of a lowland gravel bed river. The model was calibrated in order to constrain estimates of the most sensitive model parameters. The magnitude and variations of the simulated temperatures matched the observed ones, with an average mean absolute error of 0.7°C and an average Nash Sutcliffe efficiency of 0.87. Our results indicate that nonsubmerged streambed structures such as gravel bars cause substantial thermal heterogeneity within the saturated sediment at the reach scale. Individual hyporheic flow path temperatures strongly depend on the flow path residence time, flow path depth, river, and groundwater temperature. Variations in individual hyporheic flow path temperatures were up to 7.9°C, significantly higher than the daily average (2.8°C), but still lower than the average seasonal hyporheic temperature difference (19.2°C). The distribution between flow path temperatures and residence times follows a power law relationship with exponent of about 0.37. Based on this empirical relation, we further estimated the influence of hyporheic flow path residence time and temperature on oxygen consumption which was found to partly increase by up to 29% in simulations.
Modeling Transport of Cesium in Grimsel Granodiorite With Micrometer Scale Heterogeneities and Dynamic Update of Kd
Authors: Voutilainen Mikko , Kekäläinen Pekka , Siitari‐Kauppi Marja , Sardini Paul , Muuri Eveliina , Timonen Jussi , Martin Andrew 
Published: October 2017

AbstractTransport and retardation of cesium in Grimsel granodiorite taking into account heterogeneity of mineral and pore structure was studied using rock samples overcored from an in situ diffusion test at the Grimsel Test Site. The field test was part of the Long‐Term Diffusion (LTD) project designed to characterize retardation properties (diffusion and distribution coefficients) under in situ conditions. Results of the LTD experiment for cesium showed that in‐diffusion profiles and spatial concentration distributions were strongly influenced by the heterogeneous pore structure and mineral distribution. In order to study the effect of heterogeneity on the in‐diffusion profile and spatial concentration distribution, a Time Domain Random Walk (TDRW) method was applied along with a feature for modeling chemical sorption in geological materials. A heterogeneous mineral structure of Grimsel granodiorite was constructed using X‐ray microcomputed tomography (X‐μCT) and the map was linked to previous results for mineral specific porosities and distribution coefficients (Kd) that were determined using C‐14‐PMMA autoradiography and batch sorption experiments, respectively. After this the heterogeneous structure contains information on local porosity and Kd in 3‐D. It was found that the heterogeneity of the mineral structure on the micrometer scale affects significantly the diffusion and sorption of cesium in Grimsel granodiorite at the centimeter scale. Furthermore, the modeled in‐diffusion profiles and spatial concentration distributions show similar shape and pattern to those from the LTD experiment. It was concluded that the use of detailed structure characterization and quantitative data on heterogeneity can significantly improve the interpretation and evaluation of transport experiments.
Observed Hydrologic Impacts of Landfalling Atmospheric Rivers in the Salt and Verde River Basins of Arizona, United States
Authors: Demaria Eleonora M. C. , Dominguez Francina , Hu Huancui , von Glinski Gerd , Robles Marcos , Skindlov Jonathan , Walter James 
Published: October 2017

AbstractAtmospheric rivers (ARs), narrow atmospheric water vapor corridors, can contribute substantially to winter precipitation in the semiarid Southwest U.S., where natural ecosystems and humans compete for over‐allocated water resources. We investigate the hydrologic impacts of 122 ARs that occurred in the Salt and Verde river basins in northeastern Arizona during the cold seasons from 1979 to 2009. We focus on the relationship between precipitation, snow water equivalent (SWE), soil moisture, and extreme flooding. During the cold season (October through March) ARs contribute an average of 25%/29% of total seasonal precipitation for the Salt/Verde river basins, respectively. However, they contribute disproportionately to total heavy precipitation and account for 64%/72% of extreme total daily precipitation (exceeding the 98th percentile). Excess precipitation during AR occurrences contributes to snow accumulation; on the other hand, warmer than normal temperatures during AR landfallings are linked to rain‐on‐snow processes, an increase in the basins' area contributing to runoff generation, and higher melting lines. Although not all AR events are linked to extreme flooding in the basins, they do account for larger runoff coefficients. On average, ARs generate 43% of the annual maximum flows for the period studied, with 25% of the events exceeding the 10 year return period. Our analysis shows that the devastating 1993 flooding event in the region was caused by AR events. These results illustrate the importance of AR activity on the hydrology of inland semiarid regions: ARs are critical for water resources, but they can also lead to extreme flooding that affects infrastructure and human activities.
Situating Green Infrastructure in Context: A Framework for Adaptive Socio‐Hydrology in Cities
Authors: Schifman L. A. , Herrmann D. L. , Shuster W. D. , Ossola A. , Garmestani A. , Hopton M. E. 
Published: October 2017

AbstractManagement of urban hydrologic processes using green infrastructure (GI) has largely focused on storm water management. Thus, design and implementation of GI usually rely on physical site characteristics and local rainfall patterns, and do not typically account for human or social dimensions. This traditional approach leads to highly centralized storm water management in a disconnected urban landscape and can deemphasize additional benefits that GI offers, such as increased property value, greenspace aesthetics, heat island amelioration, carbon sequestration, and habitat for biodiversity. We propose the Framework for Adaptive Socio‐Hydrology (FrASH) in which GI planning and implementation moves from a purely hydrology‐driven perspective to an integrated sociohydrological approach. This allows for an iterative, multifaceted decision‐making process that would enable a network of stakeholders to collaboratively set a dynamic, context‐guided project plan for the installation of GI, rather than a “one‐size‐fits‐all” installation. We explain how different sectors (e.g., governance, nongovernmental organizations, communities, academia, and industry) can create a connected network of organizations that work toward a common goal. Through a graphical Chambered Nautilus model, FrASH is experimentally applied to contrasting GI case studies and shows that this multistakeholder, connected, decentralized network with a coevolving decision‐making project plan results in enhanced multifunctionality, potentially allowing for the management of resilience in urban systems at multiple scales.
A KDE‐Based Random Walk Method for Modeling Reactive Transport With Complex Kinetics in Porous Media
Authors: Sole‐Mari Guillem , Fernàndez‐Garcia Daniel , Rodríguez‐Escales Paula , Sanchez‐Vila Xavier 
Published: October 2017

AbstractIn recent years, a large body of the literature has been devoted to study reactive transport of solutes in porous media based on pure Lagrangian formulations. Such approaches have also been extended to accommodate second‐order bimolecular reactions, in which the reaction rate is proportional to the concentrations of the reactants. Rather, in some cases, chemical reactions involving two reactants follow more complicated rate laws. Some examples are (1) reaction rate laws written in terms of powers of concentrations, (2) redox reactions incorporating a limiting term (e.g., Michaelis‐Menten), or (3) any reaction where the activity coefficients vary with the concentration of the reactants, just to name a few. We provide a methodology to account for complex kinetic bimolecular reactions in a fully Lagrangian framework where each particle represents a fraction of the total mass of a specific solute. The method, built as an extension to the second‐order case, is based on the concept of optimal Kernel Density Estimator, which allows the concentrations to be written in terms of particle locations, hence transferring the concept of reaction rate to that of particle location distribution. By doing so, we can update the probability of particles reacting without the need to fully reconstruct the concentration maps. The performance and convergence of the method is tested for several illustrative examples that simulate the Advection‐Dispersion‐Reaction Equation in a 1‐D homogeneous column. Finally, a 2‐D application example is presented evaluating the need of fully describing non‐bilinear chemical kinetics in a randomly heterogeneous porous medium.
On the Control of Solute Mass Fluxes and Concentrations Below Fields Irrigated With Low‐Quality Water: A Numerical Study
Authors: Russo David 
Published: October 2017

AbstractThe main goal of this study was to test the capability of irrigation water‐based and soil‐based approaches to control nitrate and chloride mass fluxes and concentrations below the root zone of agricultural fields irrigated with treated waste water (TWW). Using numerical simulations of flow and transport in relatively a fine‐textured, unsaturated, spatially heterogeneous, flow domain, scenarios examined include: (i) irrigating with TWW only (REF); (ii) irrigation water is substituted between TWW and desalinized water (ADW); (iii) soil includes a capillary barrier (CB) and irrigating with TWW only (CB + TWW); and (iv) combination of (ii) and a CB (CB + ADW). Considering groundwater quality protection, plausible goals are: (i) to minimize solute discharges leaving the root zone, and, (ii) to maximize the probability that solute concentrations leaving the root zone will not exceed a prescribed, critical value. Results of the analyses suggest that in the case of a seasonal crop (a corn field) subject to irrigations only, with respect to the first goal, the CB + TWW and CB + ADW scenarios provide similar, excellent results, better than the ADW scenario; with respect to the second goal, however, the CB + ADW scenario gave substantially better results than the CB + TWW scenario. In the case a multiyear, perennial crop (a citrus orchard), subject to a sequence of irrigation and rainfall periods, for both solutes, and, particularly, nitrate, with respect to the two goals, both the ADW and CB + ADW scenarios perform better than the CB + TWW scenario. As compared with the REF and CB + TWW scenarios, the ADW and CB + ADW scenarios substantially reduce nitrogen mass fluxes to the groundwater and to the atmosphere, and, essentially, did not reduce nitrogen mass fluxes to the trees. Similar results, even better, were demonstrated for a relatively coarse‐textured, spatially heterogeneous soil.
Factor Structure, Internal Consistency and Criterion Validity of the Full‐form and Short‐form Versions of the Centrality of Events Scale in Young People
Authors: Galán Santiago , Castarlenas Elena , Racine Mélanie , Sánchez‐Rodríguez Elisabet , Tomé‐Pires Catarina , Jensen Mark P. , Miró Jordi 
Published: October 2017

SummaryThe perceived centrality of a traumatic event has been hypothesized to impact subsequent responses to that event and shown to be positively associated to a number of psychological problems. In order to understand the role of this construct in adjustment to stress and trauma, reliable and valid measures are needed. The objective of this study was to evaluate the factor structure, internal consistency and convergent validity of the full‐form and short‐forms of the Centrality of Event Scale when used with young people. A sample of 262 undergraduate students completed this study. Confirmatory factor analyses, Cronbach alpha coefficients and Pearson correlation coefficients were performed. The findings support a one‐factor structure of the full 20‐item and the short 7‐item versions. We also found that both versions provide reliable and valid scores when used with young people. We recommend the use of the 7‐item version to minimize assessment burden. Copyright © 2017 John Wiley & Sons, Ltd.