bluuebunny/crossref_metadata_2025_split huggingface dataset:
No taxon left behind? – a critical taxonomic checklist of Carpinus and Ostrya (Coryloideae, Betulaceae)
Authors: Holstein Norbert , Weigend Maximilian 
Published: December 2017

Hornbeams (Carpinus) and hop-hornbeams (Ostrya) are trees or large shrubs from the northern hemisphere. Currently, 43 species of Carpinus (58 taxa including subdivisions) and 8 species of Ostrya (9 taxa including sudivisions) are recognized. These are based on 175 (plus 16 Latin basionyms of cultivars) and 21 legitimate basionyms, respectively. We present an updated checklist with publication details and type information for all accepted names and the vast majority of synonyms of Carpinus and Ostrya, including the designation of 54 lectotypes and two neotypes. Cultivars are listed if validly described under the rules of the ICN. Furthermore, we consider Carpinus hwai Hu & W.C.Cheng to be a synonym of Carpinus fargesiana var. ovalifolia (H.J.P.Winkl.) Holstein & Weigend comb. nov. During the course of our work, we found 30 legitimate basionyms of non-cultivars that have been consistently overlooked since their original descriptions, when compared with the latest checklists and floristic treatments. As regional floras are highly important for taxonomic practice, we investigated the number of overlooked names and found that 78 basionyms were omitted at least once in the eight regional treatments surveyed. More seriously, we found 4 basionyms of accepted species being overlooked in a major floristic treatment.
L’institutionnalisation des communautés minoritaires au Canada : des communautés politiques aux politiques communautaires ?
Authors: Fournis Yann 
Published: December 2017

Objet énigmatique, les communautés sont le sujet d’analyses originales au Canada, qui peinent néanmoins à sortir de la dichotomie entre les approches « socio-centrées » et les approches « stato-centrées » de la politique de la reconnaissance. Dans cet article, nous proposons une lecture néo-institutionnaliste des communautés minoritaires, qui conduit à comprendre les communautés comme le résultat de l’interaction entre les dynamiques sociales internes au groupe et les politiques publiques de construction nationale mises en place par le gouvernement fédéral. Une première partie est consacrée à des travaux sur les identités minoritaires qui, en termes de nationalisme régional ou de complétude institutionnelle, considèrent que les communautés sont desmini-politiesoù l’usage de l’identité permet un traitement collectif des enjeux communautaires. Dans une deuxième partie, nous revenons sur les travaux récents qui suggèrent que les États en Amérique du Nord, formellement « faibles », devraient être compris comme disposant d’une forte capacité d’action, un pouvoir infrastructurel pour construire uneméta-polity. L’État fédéral a ainsi mis en place des politiques publiques communautaires qui construisent des communautés conformes à ses stratégies de construction nationale. La conclusion revient sur la « nature » des communautés au Canada pour questionner la pertinence de la notion de complétude institutionnelle comme réponse ascendante à la gouvernementalité descendante de l’État fédéral.
Optimal Design for Placements of Tsunami Observing Systems to Accurately Characterize the Inducing Earthquake
Authors: Mulia Iyan E. , Gusman Aditya Riadi , Satake Kenji 
Published: December 2017

AbstractRecently, there are numerous tsunami observation networks deployed in several major tsunamigenic regions. However, guidance on where to optimally place the measurement devices is limited. This study presents a methodological approach to select strategic observation locations for the purpose of tsunami source characterizations, particularly in terms of the fault slip distribution. Initially, we identify favorable locations and determine the initial number of observations. These locations are selected based on extrema of empirical orthogonal function (EOF) spatial modes. To further improve the accuracy, we apply an optimization algorithm called a mesh adaptive direct search to remove redundant measurement locations from the EOF‐generated points. We test the proposed approach using multiple hypothetical tsunami sources around the Nankai Trough, Japan. The results suggest that the optimized observation points can produce more accurate fault slip estimates with considerably less number of observations compared to the existing tsunami observation networks.
Where Does Wood Most Effectively Enhance Storage? Network‐Scale Distribution of Sediment and Organic Matter Stored by Instream Wood
Authors: Pfeiffer Andrew , Wohl Ellen 
Published: December 2017

AbstractWe used 48 reach‐scale measurements of large wood and wood‐associated sediment and coarse particulate organic matter (CPOM) storage within an 80 km2 catchment to examine spatial patterns of storage relative to stream order. Wood, sediment, and CPOM are not distributed uniformly across the drainage basin. Third‐ and fourth‐order streams (23% of total stream length) disproportionately store wood and coarse and fine sediments: 55% of total wood volume, 78% of coarse sediment, and 49% of fine sediment, respectively. Fourth‐order streams store ~0.8 m3 of coarse sediment and 0.2 m3 of fine sediment per cubic meter of wood. CPOM storage is highest in first‐order streams (60% of storage in 47% of total network stream length). First‐order streams can store up to 0.3 m3 of CPOM for each cubic meter of wood. Logjams in third‐ and fourth‐order reaches are primary sediment storage agents, whereas roots in small streams may be more important for storage of CPOM. We propose the large wood particulate storage index to quantify average volume of sediment or CPOM stored by a cubic meter of wood.
Drop Height and Volume Control the Mobility of Long‐Runout Landslides on the Earth and Mars
Authors: Johnson Brandon C. , Campbell Charles S. 
Published: December 2017

AbstractLong‐runout landslides are landslides with volumes of 105 m3 or more, which move much farther from their source than expected. The observation that Martian landslides are generally less mobile than terrestrial landslides offers important evidence regarding the mechanism responsible for the high mobility of long‐runout landslides. Here we simulate landslides as granular flow using a soft‐particle discrete element model. We show that while surface gravity plays a negligible role, observed differences in fall height naturally reproduce the observed differences in mobility of Martian and terrestrial landslides. We also demonstrate that landslides on Iapetus may fit this trend. Our simulations do not include any fluid and indicate that a mechanism similar to acoustic fluidization can explain the high mobility of long‐runout landslides. This implies that long‐runout landslides on Mars should not be considered as evidence for ice, saturated clays, or liquid water.
Equatorial E Region Electric Fields and Sporadic E Layer Responses to the Recovery Phase of the November 2004 Geomagnetic Storm
Authors: Moro J. , Resende L. C. A. , Denardini C. M. , Xu J. , Batista I. S. , Andrioli V. F. , Carrasco A. J. , Batista P. P. , Schuch N. J. 
Published: December 2017

AbstractEquatorial E region electric fields (EEFs) inferred from coherent radar data, sporadic‐E (Es) layers observed from a digital ionosonde data, and modeling results are used to study the responses of the equatorial E region over São Luís (SLZ, 2.3°S, 44.2°W, ~−7° dip angle), Brazil, during the super storm of November 2004. The EEF is presented in terms of the zonal (Ey) and vertical (Ez) components in order to analyze the corresponding characteristics of different types of Es seen in ionograms and simulated with the E region ionospheric model. We bring out the variabilities of Ey and Ez components with storm time changes in the equatorial E region. In addition, some aspects of the electric fields and Es behavior in three cases of weak, very weak, and strong Type II occurrences during the recovery phase of the geomagnetic storm are discussed. The connection between the enhanced occurrence and suppressions of the Type II irregularities and the q‐type Es (Esq) controlled by electric fields, with the development or disruption of the blanketing sporadic E (Esb) layers produced by wind shear mechanism, is also presented. The mutual presence of Esq along with the Esb occurrences is a clear indicator of the secular drift of the magnetic equator and hence that of the equatorial electrojet (EEJ) over SLZ. The results show evidence about the EEJ and Es layer electrodynamics and coupling during geomagnetic disturbance time electric fields.
Magnetic Shear Damped Polar Convective Fluid Instabilities
Authors: Atul Jyoti K. , Singh Rameswar , Sarkar Sanjib , Kravchenko Oleg V. , Singh Sushil K. , Chattopadhyaya Prabal K. , Kaw Predhiman K. 
Published: December 2017

AbstractThe influence of the magnetic field shear is studied on the E × B (and/or gravitational) and the Current Convective Instabilities (CCI) occurring in the high‐latitude F layer ionosphere. It is shown that magnetic shear reduces the growth rate of these instabilities. The magnetic shear‐induced stabilization is more effective at the larger‐scale sizes (≥ tens of kilometers) while at the scintillation causing intermediate scale sizes (∼ a few kilometers), the growth rate remains largely unaffected. The eigenmode structure gets localized about a rational surface due to finite magnetic shear and has broken reflectional symmetry due to centroid shift of the mode by equilibrium parallel flow or current.
Interpreting Dust Impact Signals Detected by the STEREO Spacecraft
Authors: O'Shea E. , Sternovsky Z. , Malaspina D. M. 
Published: December 2017

AbstractThere is no comprehensive understanding yet of how dust impacts on spacecraft (SC) generate signals detected by antenna instruments. The high sensitivity of the S/WAVES instrument and the large number and high diversity of dust impacts detected make the STEREO mission particularly well suited for a closer investigation. A floating perturbation model (FPP) was recently proposed to explain the characteristic shape of dust impact signals with an overshoot. The FPP model posits that the overshoot is due to the different discharge time constant of the SC and the individual antennas. Kinetic simulations are performed to demonstrate that, contrary to common belief, antennas are inefficient collectors of charged particles from impact plasmas. The collection efficiency is small, only 0.1–1%, varying weakly with the bias potential between the antenna and the SC, and more strongly with impact location. The low recollection efficiencies and an analysis of the shapes and scaling of typical and atypical signals recorded by S/WAVES suggest that, besides the mechanism described by the FPP model, there is another, possibly stronger mechanism that is responsible for generating the characteristic overshoot for most dust impact signals observed by STEREO.
Temporal Changes in Stress Drop, Frictional Strength, and Earthquake Size Distribution in the 2011 Yamagata‐Fukushima, NE Japan, Earthquake Swarm, Caused by Fluid Migration
Authors: Yoshida Keisuke , Saito Tatsuhiko , Urata Yumi , Asano Youichi , Hasegawa Akira 
Published: December 2017

AbstractIn this study, we investigated temporal variations in stress drop and b‐value in the earthquake swarm that occurred at the Yamagata‐Fukushima border, NE Japan, after the 2011 Tohoku‐Oki earthquake. In this swarm, frictional strengths were estimated to have changed with time due to fluid diffusion. We first estimated the source spectra for 1,800 earthquakes with 2.0 ≤ MJMA < 3.0, by correcting the site‐amplification and attenuation effects determined using both S waves and coda waves. We then determined corner frequency assuming the omega‐square model and estimated stress drop for 1,693 earthquakes. We found that the estimated stress drops tended to have values of 1–4 MPa and that stress drops significantly changed with time. In particular, the estimated stress drops were very small at the beginning, and increased with time for ~50 days. Similar temporal changes were obtained for b‐value; the b‐value was very high (b ~ 2) at the beginning, and decreased with time, becoming approximately constant (b ~ 1) after ~50 days. Patterns of temporal changes in stress drop and b‐value were similar to the patterns for frictional strength and earthquake occurrence rate, suggesting that the change in frictional strength due to migrating fluid not only triggered the swarm activity but also affected earthquake and seismicity characteristics. The estimated high Q−1 value, as well as the hypocenter migration, supports the presence of fluid, and its role in the generation and physical characteristics of the swarm.
Is There a Link Between Mineralogy, Petrophysics, and the Hydraulic and Seismic Behaviors of the Soultz‐sous‐Forêts Granite During Stimulation? A Review and Reinterpretation of Petro‐Hydromechanical Data Toward a Better Understanding of Induced Seismicity and Fluid Flow
Authors: Meller Carola , Ledésert Béatrice 
Published: December 2017

AbstractIn the framework of the European Soultz‐sous‐Forêts enhanced geothermal system (EGS) in Alsace, France, 20 years of scientific and preindustrial tests had to be performed before the site began production of electricity in 2008. Stimulation tests were designed to enhance the permeability because most of the numerous natural fractures that crosscut the granite body were sealed by secondary minerals that crystallized as an effect of the circulation of local hot brines. The deep‐seated granitic reservoir is located between 4,500 and 5,000 m depths. Hydraulic stimulations were conducted in the four deep wells (GPK1, GPK2, GPK3, and GPK4) inducing different microseismic event patterns, which cannot be explained by tectonic structures alone. In the present work, we provide a review of the hydraulic tests and reinterpret them in the light of mineralogical data obtained along the boreholes. A clear relationship appears between mineralogy (mainly clay and calcite content) and the petrophysical, mechanical, and hydraulic behaviors of the rock mass. High calcite contents are correlated with an abundance of clay minerals, low Young's modulus, low magnetic susceptibility, and variation in spectral gamma ray. Microearthquakes are generated in the fresh granite zones, while clay and calcite‐rich zones, linked with hydrothermal alteration, might behave aseismically during hydraulic stimulations. These findings highlight the importance of a detailed knowledge of the petrography of a reservoir to conduct an effective stimulation while keeping the seismic hazard at a minimum.
A Systematic Comparison of Particle Filter and EnKF in Assimilating Time‐Averaged Observations
Authors: Liu Huaran , Liu Zhengyu , Lu Feiyu 
Published: December 2017

AbstractThe particle filter (PF) and the ensemble Kalman filter (EnKF) are two promising and popularly adopted types of ensemble‐based data assimilation methods for paleoclimate reconstruction. However, no systematic comparison between them has been attempted. We compare these two uncertainty based methods in pseudoproxy experiments where synthetic seasonal mean sea surface temperature observations are assimilated. Their skills are evaluated with regards to local, hemispherically averaged and globally averaged analysis error, and their ability to capture large‐scale modes of variability. It is found that the EAKF (Ensemble Adjustment Kalman filter, a variant of EnKF) performs better than the PF with only one third of the ensemble size, despite PF's theoretical superiority in allowing for non‐Gaussian statistics and nonlinear dynamics. The success of the EAKF is attributed to the facts that (1) Gaussian assumption is somewhat appropriate for this application; (2) The EAKF is less sensitive to sampling errors than the PF due to the different methodological natures. Sixteen members are enough to estimate accurate covariance for the EAKF, but 48 (even 96) members still underrepresent the state space of high‐dimensional system for the PF. Our study highlights the importance of a large localization radius in the application of the EnKF to paleoclimate reconstruction due to the sparse proxy network and suggests that additional techniques, such as localization or clustered particle filter, are needed to improve the PF for paleoclimate reconstruction, in addition to the simple importance resampling currently adopted by most research.
Investigating Local and Remote Terrestrial Influence on Air Masses at Contrasting Antarctic Sites Using Radon‐222 and Back Trajectories
Authors: Chambers S. D. , Choi T. , Park S.‐J. , Williams A. G. , Hong S.‐B. , Tositti L. , Griffiths A. D. , Crawford J. , Pereira E. 
Published: December 2017

AbstractWe report on the first summer of high‐sensitivity radon measurements from a two‐filter detector at Jang Bogo Station (Terra Nova Bay) and contrast them with simultaneous observations at King Sejong Station (King George Island). King Sejong radon concentrations were characteristic of a marine baseline station (0.02–0.3 Bq m−3), whereas Jang Bogo values were highly variable (0.06–5.2 Bq m−3), mainly due to emissions from exposed coastal ground (estimated mean flux 0.09–0.11 atoms cm−2 s−1) and shallow atmospheric mixing depths. For wind speeds of ≤3.5 m s−1 the influence of local radon emissions became increasingly more prominent at both sites. A cluster analysis of back trajectories from King Sejong (62°S) revealed a fairly even distribution between air masses that had passed recently over South America, the Southern Ocean, and Antarctica, whereas at Jang Bogo (75°S) 80% of events had recently passed over the Ross Ice Shelf and West Antarctica, 12% were synoptically forced over Cape Adare, and 8% were associated with subsidence over the Antarctic interior and katabatic flow to the station. When cross‐checked against radon concentrations, only half of the back trajectories ending at Jang Bogo that had indicated distant contact with nonpolar southern hemisphere continents within the past 10 days showed actual signs of terrestrial influence. A simple‐to‐implement technique based on high‐pass filtered absolute humidity is developed to distinguish between predominantly katabatic, oceanic, and near‐coastal air masses for characterization of trace gas and aerosol measurements at coastal East Antarctic sites.
Multi‐Timescale Analysis of the Spatial Representativeness of In Situ Soil Moisture Data within Satellite Footprints
Authors: Molero B. , Leroux D. J. , Richaume P. , Kerr Y. H. , Merlin O. , Cosh M. H. , Bindlish R. 
Published: December 2017

AbstractWe conduct a novel comprehensive investigation that seeks to prove the connection between spatial scales and timescales in surface soil moisture (SM) within the satellite footprint (~50 km). Modeled and measured point series at Yanco and Little Washita in situ networks are first decomposed into anomalies at timescales ranging from 0.5 to 128 days, using wavelet transforms. Then, their degree of spatial representativeness is evaluated on a per‐timescale basis by comparison to large spatial scale data sets (the in situ spatial average, SMOS, AMSR2, and ECMWF). Four methods are used for this: temporal stability analysis (TStab), triple collocation (TC), percentage of correlated areas (CArea), and a new proposed approach that uses wavelet‐based correlations (WCor). We found that the mean of the spatial representativeness values tends to increase with the timescale but so does their dispersion. Locations exhibit poor spatial representativeness at scales below 4 days, while either very good or poor representativeness at seasonal scales. Regarding the methods, TStab cannot be applied to the anomaly series due to their multiple zero‐crossings, and TC is suitable for week and month scales but not for other scales where data set cross‐correlations are found low. In contrast, WCor and CArea give consistent results at all timescales. WCor is less sensitive to the spatial sampling density, so it is a robust method that can be applied to sparse networks (one station per footprint). These results are promising to improve the validation and downscaling of satellite SM series and the optimization of SM networks.
Latitudinal and Seasonal Variations of Vertical Wave Number Spectra of Three‐Dimensional Winds Revealed by Radiosonde Observations
Authors: Zhang Shao Dong , Huang Chun Ming , Huang Kai Ming , Gong Yun , Chen Gang , Gan Quan , Zhang Ye Hui 
Published: December 2017

AbstractAiming at investigating the vertical wave number spectral features of three‐dimensional winds in the lower atmosphere as well as their latitudinal and seasonal variations, we analyzed 11 year (1998–2008) radiosonde data from 92 United States stations in the Northern Hemisphere. The spatiotemporal variation of the horizontal wind spectral amplitude agrees well with that of the inertial gravity wave energy, revealing that the observed horizontal wind spectra are mainly attributed to the inertial gravity waves. The horizontal wind spectral slope is systematically and climatologically less negative than the canonical value of −3. For the first time we found that the vertical wind spectrum is much shallower than the horizontal wind spectrum over a wide latitude region, with slopes varying in −1.1 to −0.2 (−0.6 to 0.1) in the troposphere (lower stratosphere). Besides the slopes, the height, latitudinal, and seasonal variations of the vertical wind spectral showed evident difference from those of the horizontal wind spectrum. These differences are due to the horizontal and vertical wind spectra that might be constituted mainly by low and high frequency waves, respectively. Both the horizontal wind and vertical wind spectra exhibit evident universal features, which are more prominent in the lower stratosphere than in the troposphere, where it is thought to be the main source region of gravity waves, implying that the dynamical processes in the wave propagation might be the main cause of the universal spectrum. The background wind was found to have significant impact on the horizontal wind spectrum but has only weak impact on the vertical wind spectrum.
Porosity and Salt Content Determine if Subduction Can Occur in Europa's Ice Shell
Authors: Johnson Brandon C. , Sheppard Rachel Y. , Pascuzzo Alyssa C. , Fisher Elizabeth A. , Wiggins Sean E. 
Published: December 2017

AbstractMotivated by recent evidence for subduction in Europa's ice shell, we explore the geophysical feasibility of this process. Here we construct a simple model to track the evolution of porosity and temperature within a slab that is forced to subduct. We also vary the initial salt content in Europa's ice shell and determine the buoyancy of our simulated subducting slab. We find that porosity and salt content play a dominant role in determining whether the slab is nonbuoyant and subduction in Europa's ice shell is actually possible. Generally, we find that initially low porosities and high salt contents within the conductive lid are more conducive to subduction. If salt contents are laterally homogenous, and Europa has a reasonable surface porosity of ϕ0 = 0.1, the conductive portion of Europa's shell must have salt contents exceeding ~22% for subduction to occur. However, if salt contents are laterally heterogeneous, with salt contents varying by a few percent, subduction may occur for a surface porosity of ϕ0 = 0.1 and overall salt contents of ~5%. Thus, we argue that under plausible conditions, subduction in Europa's ice shell is possible. Moreover, assuming that subduction is actively occurring or has occurred in Europa's recent past provides important constraints on the structure and composition of the ice shell.