bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relation Between Arctic Moisture Flux and Tropical Temperature Biases in CMIP5 Simulations and Its Fingerprint in RCP8.5 Projections
Authors: Lee Sukyoung , Woods Cian , Caballero Rodrigo 
Published: January 2019

AbstractArctic moisture intrusions have played an important role in warming the Arctic over the past few decades. A prior study found that Coupled Model Intercomparison Project Phase 5 (CMIP5) models exhibit large regional biases in the moisture flux across 70°N. It is shown here that the systematic misrepresentation of the moisture flux is related to the models' overprediction of zonal wavenumber k = 2 contribution and underprediction of k = 1 contribution to the flux. Models with a warmer tropical upper troposphere and El‐Niño‐like tropical surface temperature tend to simulate stronger k = 2 flux, while k = 1 flux is uncorrelated with tropical upper tropospheric temperature and is associated with La‐Niña‐like surface temperature. The models also overpredict the transient eddy moisture flux while underpredicting the stationary eddy flux. Moreover, future projections in Representative Concentration Pathway 8.5 (RCP8.5) simulations show trends in moisture flux that is consistent with biases in historical simulations, suggesting that these CMIP5 projections reflect the same error(s) that cause the model biases.
Development of Side Bidirectional Leader and Its Effect on Channel Branching of the Progressing Positive Leader of Lightning
Authors: Yuan Shanfeng , Jiang Rubin , Qie Xiushu , Sun Zhuling , Wang Dongfang , Srivastava Abhay 
Published: January 2019

AbstractFine time‐resolved images of the development of lightning bidirectional leaders below the cloud base were captured by a high‐speed camera in association with multiband electromagnetic field measurements. The bileaders tended to originate at a radial distance of about 200 m from a progressing positive leader channel, propagating more or less radially toward and away from the main channel. Significant asymmetrical channel extensions at opposite ends were clearly recognized. The positive ends of the bileaders propagated in single paths with average speed of 6.1 × 104 m/s, while the opposite negative end involved obvious branching and stepping propagation with average speed of 1.6 × 105 m/s. The bidirectional leaders eventually connected to the existing main positive leader, producing new branches of the flash. Another cause of positive leader branching was that the positive leader split at its head and developed into different branches synchronously, which were sometimes invisible but were revealed by recoil leaders.
How Does the Seasonal Cycle Control Equatorial Atlantic Interannual Variability?
Authors: Prodhomme C. , Voldoire A. , Exarchou E. , Deppenmeier A.‐L. , García‐Serrano J. , Guemas V. 
Published: January 2019

AbstractIt has long been thought that reducing mean‐state biases would lead to improvements in variability. However, so far, there is no confirmation of a relation between model mean biases and variability. While most coupled models exhibit substantial sea surface temperature (SST) biases in the Tropical Atlantic, they are still able to reproduce reasonable SST variability in the basin. We investigate the relationship between the first‐ and second‐order moments of the SST distribution in the equatorial Atlantic using Coupled Model Intercomparison Project Phase 5 simulations. Results suggest that the ability of the coupled models to properly reproduce the interannual variability is linked to their ability to simulate a realistic seasonal cycle evolution, that is, a realistic cold tongue development and a realistic Bjerknes feedback during the beginning of summer, rather than to their ability to represent the summer SST climatology.
Statistical Properties of Sub‐Ion Magnetic Holes in the Dipolarized Magnetotail: Formation, Structure, and Dynamics
Authors: Shustov P. I. , Zhang X.‐J. , Pritchett P. L. , Artemyev A. V. , Angelopoulos V. , Yushkov E. V. , Petrukovich A. A. 
Published: January 2019

AbstractMagnetic energy release during magnetic reconnection in the magnetotail leads to fast plasma flows transporting thermal energy toward the inner magnetosphere or deep tail. The interaction of such flows with the ambient plasmas is controlled by forces at the flow's leading edge, manifested as a sharp enhancement of the south‐north component of magnetic field there, which has been called the dipolarization front. In this study, we examine the kinetic plasma structure of equatorial magnetic field perturbations observed behind dipolarization fronts. Using statistical observations of dipolarization fronts in the near‐Earth magnetotail by Time History of Events and Macroscale Interactions during Substorms mission, we find sub‐ion scale (scale is below ion gyroradius) magnetic field depressions (magnetic holes), mostly around the equatorial plane, drifting dawnward. They are populated by hot, transversely anisotropic electrons, likely heated around the front. Combining spacecraft observations, analytical estimates, and particle‐in‐cell simulations, we suggest that these holes result from the ballooning/interchange instability at the dipolarization front. They may represent the nonlinear stage of magnetic field perturbations associated with front instability, which trap hot electrons behind the front. We also discuss the possible role of these holes in scattering and heating electrons and ions in the dipolarized magnetotail.
Variability of Intra–D Ring Azimuthal Magnetic Field Profiles Observed on Cassini's Proximal Periapsis Passes
Authors: Provan G. , Cowley S. W. H. , Bunce E. J. , Bradley T. J. , Hunt G. J. , Cao H. , Dougherty M. K. 
Published: January 2019

AbstractWe overview the properties of the azimuthal magnetic fields observed during the periapsis passes of the final 23 orbits of the Cassini spacecraft, including the partial orbit at end of mission, on near equatorial field lines passing inside of Saturn's D ring. The signatures are variable in form and amplitude, though generally approximately symmetric about the point where the spacecraft trajectory lies tangent to a flux shell, corresponding to where the ionospheric field line feet map closest to the equator, consistent with the effect of interhemispheric field‐aligned currents. The perturbations usually begin and end near symmetrically at some point on field lines threading the D ring and extend into the interior region, but in no case do they clearly extend outward onto field lines passing through the C ring. About 35% of cases display a ~20‐40 nT single positive central field peak indicative of southward field‐aligned current flow, while a further ~30% display two or three weaker ~10‐20 nT positive peaks indicative of multiple sheets of northward and southward current. Significant smaller‐scale >5 nT peak‐to‐peak field fluctuations are commonly superposed. A further ~20% of cases exhibit unique profiles within the data set, including two with ~20‐30 nT negative fields and two with only <10 nT fluctuating fields. The variable nature of the signatures is not connected with the pass altitude, local time, planetary period oscillation phase, or D68 ringlet phase but may relate to variable structured thermospheric winds and/or ionospheric conductivities that suggest a significant dynamical role for D ring‐atmosphere interactions.
Paleoearthquakes and Rupture Behavior of the Lenglongling Fault: Implications for Seismic Hazards of the Northeastern Margin of the Tibetan Plateau
Authors: Guo Peng , Han Zhujun , Mao Zebin , Xie Zhangdi , Dong Shaopeng , Gao Fan , Gai Hailong 
Published: January 2019

AbstractThe Lenglongling fault (LLLF) is located along the northeastern margin of the Tibetan Plateau and forms a part of the Tianzhu seismic gap along the Qilian‐Haiyuan fault zone. Little is known about the recurrence of large earthquakes along the LLLF nor the associated seismic hazards of the gap. Here the six most recent surface rupturing paleoearthquakes of the LLLF are revealed by measurement of offset landforms, trench excavations, and radiocarbon dating. They are labeled E1–E6 from youngest to oldest, and their timings are constrained to the following time ranges: 636–498 to present, 2951–1155, 4016–3609, 5325–4476, 7284–6690, and 8483–7989 years BP, respectively. The LLLF displays evidence of fresh, recent surface rupture, and the trench sections reveal that the fault ruptured to the ground surface during the most recent event. Based on this fresh surface rupture and historical earthquake records, the latest event E1 was most likely the 1927 M8.0 Gulang earthquake. In conjunction with previous studies, Gulang earthquake might be a complicated event characterized by the combined rupture of both strike‐slip and thrust faults. The average recurrence interval of the six paleoearthquakes is 1643 ± 568 years, and the coefficient of variation is 0.34, indicating that the LLLF follows a quasiperiodic recurrence model. Based on this new understanding of the last event, the LLLF may not be a part of the Tianzhu seismic gap. However, an earthquake of up to MW7.6 could still rupture the gap sections composed of the Jinqianghe, Maomaoshan, and Laohushan faults.
Early Inception of the Laramide Orogeny in Southwestern Montana and Northern Wyoming: Implications for Models of Flat‐Slab Subduction
Authors: Carrapa B. , DeCelles P. G. , Romero M. 
Published: January 2019

AbstractTiming and distribution of magmatism, deformation, exhumation, and basin development have been used to reconstruct the history of Laramide flat‐slab subduction under North America during Late Cretaceous‐early Cenozoic time. Existing geodynamic models, however, ignore a large (~40,000‐km2) sector of the Laramide foreland in southwestern Montana. The Montana Laramide ranges consist of Archean basement arches (fault‐propagation folds) that were elevated by thrust and reverse faults. We present new thermochronological and geochronological data from six Laramide ranges in southwestern Montana (the Beartooth, Gravelly, Ruby and Madison Ranges, and the Tobacco Root and Highland Mountains) that show significant cooling and exhumation during the Early to mid‐Cretaceous, much earlier than the record of Laramide exhumation in Wyoming. These data suggest that Laramide‐style deformation‐driven exhumation slightly predates the eastward sweep of magmatism in western Montana, consistent with geodynamic models involving initial strain propagation into North American cratonic rocks due to stresses associated with a northeastward expanding region of flat‐slab subduction. Our results also indicate various degrees of Cenozoic heating and cooling possibly associated with westward rollback of the subducting Farallon slab, followed by Basin‐and‐Range extension.
Transverse Momentum Exchange Induced by Large Coherent Structures in a Vegetated Compound Channel
Authors: Truong S. H. , Uijttewaal W. S. J. 
Published: January 2019

AbstractIn floodplains of vegetated channels, transverse exchange processes of mass and momentum are of primary importance as these are directly linked to the river bank stability, sedimentation, and nutrient transport. Despite its importance, knowledge about this phenomenon is still incomplete especially in the context of the presence of the large horizontal coherent structures (LHCSs). As a result, although various exchange models have been developed, their applicability in different circumstances is still unclear as their validity is usually restricted to a narrowly ranging experiment data set. A proper model for this exchange in a compound channel geometry with or without vegetation is lacking. In order to obtain more insight, a laboratory experiment of a shallow flow field in a compound vegetated channel has been conducted. A quadrant analysis of the Reynolds shear stresses has been applied to study the connection between the cycloid flow events induced by the LHCSs and transverse momentum exchange in the channel. It is suggested that local variability leads to differences in the transverse exchange of momentum. Furthermore, the experimental data were used to verify state‐of‐the‐art momentum exchange models. As the limitations of those models were analyzed, for the first time a hybrid eddy viscosity model based on the occurrence of LHCSs and the presence of vegetation was proposed and validated using a variety of experimental data sets. The results suggest that the transverse momentum exchange can be well modeled with the new eddy viscosity model for quite a range of different setups and scenarios by varying only a coefficient of proportionality β, which is related to the transverse slope between the main channel and the floodplain.
Combining Physically Based Modeling and Deep Learning for Fusing GRACE Satellite Data: Can We Learn From Mismatch?
Authors: Sun Alexander Y. , Scanlon Bridget R. , Zhang Zizhan , Walling David , Bhanja Soumendra N. , Mukherjee Abhijit , Zhong Zhi 
Published: January 2019

AbstractGlobal hydrological and land surface models are increasingly used for tracking terrestrial total water storage (TWS) dynamics, but the utility of existing models is hampered by conceptual and/or data uncertainties related to various underrepresented and unrepresented processes, such as groundwater storage. The gravity recovery and climate experiment (GRACE) satellite mission provided a valuable independent data source for tracking TWS at regional and continental scales. Strong interests exist in fusing GRACE data into global hydrological models to improve their predictive performance. Here we develop and apply deep convolutional neural network (CNN) models to learn the spatiotemporal patterns of mismatch between TWS anomalies (TWSA) derived from GRACE and those simulated by NOAH, a widely used land surface model. Once trained, our CNN models can be used to correct the NOAH‐simulated TWSA without requiring GRACE data, potentially filling the data gap between GRACE and its follow‐on mission, GRACE‐FO. Our methodology is demonstrated over India, which has experienced significant groundwater depletion in recent decades that is nevertheless not being captured by the NOAH model. Results show that the CNN models significantly improve the match with GRACE TWSA, achieving a country‐average correlation coefficient of 0.94 and Nash‐Sutcliff efficient of 0.87, or 14% and 52% improvement, respectively, over the original NOAH TWSA. At the local scale, the learned mismatch pattern correlates well with the observed in situ groundwater storage anomaly data for most parts of India, suggesting that deep learning models effectively compensate for the missing groundwater component in NOAH for this study region.
Comment on “Analytical Estimation Show Low Depth‐Independent Water Loss Due to Vapor Flux From Deep Aquifers by John S. Selker (2017)”
Authors: Shokri Nima 
Published: January 2019

AbstractSelker (2017, https://doi.org/10.1002/2017WR021014) recently presented an analytical estimation of evaporative fluxes from deep aquifers. Regardless of the type of soil, ambient temperature, and relative humidity, assumed the thickness of liquid region above the water table equals to zero. Here we illustrate the limitation of this assumption and its impact on the estimation of the evaporative fluxes from deep aquifers.
Toward Optimizing LNAPL Remediation
Authors: Sookhak Lari Kaveh , Rayner John L. , Davis Greg B. 
Published: January 2019

AbstractOptimizing the remediation of light nonaqueous phase liquids (LNAPLs) to achieve an acceptable endpoint status for a site is not trivial. Recently, Sookhak Lari, Johnston, et al. (2018, https://doi.org/10.1016/j.jhazmat.2017.11.006), Sookhak Lari, Rayner, and Davis (2018, https://doi.org/10.1016/j.jenvman.2018.07.041) conducted three‐dimensional multiphase, multicomponent simulations to address LNAPL remediation endpoints for a single recovery well. However, optimized LNAPL remediation for multiple wells is not addressed in the literature. In the first part of this paper, we establish a matrix of 10 simulation scenarios to show the sensitivity of the remedial endpoint (i.e., what is feasibly achieved) to several parameters including viscosity and partitioning attributes of the LNAPL, heterogeneity of the formation, and the location and number of the recovery wells. While this addresses the variability of LNAPL removal from the subsurface and is valuable in its own right, it does not address the optimal removal of LNAPL. We address this in the second part of the paper by linking a genetic algorithm to TMVOC‐MP to allow, for example, the assessment of the optimal number and location of LNAPL recovery wells in a field‐scale problem. Using supercomputing facilities and within 49 genetic algorithm generations, each including 150 members, highly optimized answers to different objective functions were obtained. For the first time, such a multiphase, multicomponent optimization tool promises the possibility of optimizing LNAPL remediation at field scale to achieve practicable endpoint conditions, within computational affordability.
An Intercomparison of Noah Model Skills With Benefits of Assimilating SMOPS Blended and Individual Soil Moisture Retrievals
Authors: Yin Jifu , Zhan Xiwu , Liu Jicheng , Schull Mitch 
Published: January 2019

AbstractSoil moisture (SM) data from Soil Moisture Operational Product System (SMOPS) have been available and used by users since 2013, and the latest version (3.0) has been operationally released since 2017. The version 3.0 provides a combination of currently all available daily global microwave SM retrievals including observations of ASCATA, ASCATB, SMAP, SMOS, and AMSR2 from 1 April 2015 to present. This study intercompares Noah model skills with benefits of assimilating the SMOPS blended (hereafter, SMOPS) and the five individual satellite SM retrievals. Results show that SMOPS SM product presents a significant advantage in data availability in comparison with the individual SM retrievals. Significant differences in data availability, climatology, and dynamic range of SM values between the bias‐corrected SMOPS and individual SM data lead to remarkable distinctions in Noah model SM simulations. Significant improvements of assimilating individual and blended satellite SM retrievals on model SM simulations versus the open loop in both surface and root zone soil layers are evident with reducing the Soil Climate Analysis Network measurements‐based root mean square errors and raising the correlations with respect to the enhanced vegetation index. Compared to the individual SM assimilations, model SM estimations with benefits of assimilating the SMOPS data provide the more remarkable improvements in surface soil layer.
Coxsackievirus A10 atomic structure facilitating the discovery of a broad-spectrum inhibitor against human enteroviruses
Authors: Chen Jinhuan , Ye Xiaohua , Zhang Xue-Yang , Zhu Zhengdan , Zhang Xiang , Xu Zhijian , Ding Zhanyu , Zou Gang , Liu Qingwei , Kong Liangliang , Jiang Wen , Zhu Weiliang , Cong Yao , Huang Zhong 
Published: January 2019

AbstractCoxsackievirus A10 (CV-A10) belongs to theEnterovirusspecies A and is a causative agent of hand, foot, and mouth disease. Here we present cryo-EM structures of CV-A10 mature virion and native empty particle (NEP) at 2.84 and 3.12 Å, respectively. Our CV-A10 mature virion structure reveals a density corresponding to a lipidic pocket factor of 18 carbon atoms in the hydrophobic pocket formed within viral protein 1. By structure-guided high-throughput drug screening and subsequent verification in cell-based infection-inhibition assays, we identified four compounds that inhibited CV-A10 infection in vitro. These compounds represent a new class of anti-enteroviral drug leads. Notably, one of the compounds, ICA135, also exerted broad-spectrum inhibitory effects on a number of representative viruses from all four species (A–D) of human enteroviruses. Our findings should facilitate the development of broadly effective drugs and vaccines for enterovirus infections.
Theoretical Study of Lumped Parameter Circuits and Multiconductor Transmission Lines for Time-Domain Analysis of Electromagnetic Noise
Authors: Abe Masayuki , Toki Hiroshi 
Published: January 2019

AbstractIn order to find the origins of electromagnetic noise in the time domain, we formulate a system of lumped parameter circuits and multiconductor transmission lines (MTL). We present a discretized approach to treat any lumped parameter circuits and MTL systems, and the boundary conditions between these systems, where the lumped parameter circuits are described by coupled differential equations, and the MTL systems by coupled partial-differential equations. The introduction of the time-domain impedance and the element matrices enables us to perform a time-domain analysis that includes dependent sources and the coupling devices in the framework of the circuit theory. For three-line systems, we are able to calculate the coupling of the normal, common, and antenna modes, and to find out methods to reduce the noise.
Impaired Nuclear Export of Polyglutamine-Expanded Androgen Receptor in Spinal and Bulbar Muscular Atrophy
Authors: Arnold Frederick J. , Pluciennik Anna , Merry Diane E. 
Published: January 2019

AbstractSpinal and bulbar muscular atrophy (SBMA) is a neuromuscular disease caused by polyglutamine (polyQ) expansion in the androgen receptor (AR). Prior studies have highlighted the importance of AR nuclear localization in SBMA pathogenesis; therefore, in this study, we sought to determine the role of AR nuclear export in the pathological manifestations of SBMA. We demonstrate here that the nuclear export of polyQ-expanded AR is impaired, even prior to the formation of intranuclear inclusions of aggregated AR. Additionally, we find that promoting AR export with an exogenous nuclear export signal substantially reduces its aggregation and blocks hormone-induced toxicity. Moreover, we show that these protective effects are conferred by destabilization of the mutant protein due to an increase in proteasomal degradation of the cytoplasmic AR. Despite a growing body of evidence that global disruption of nucleo/cytoplasmic transport occurs in ALS and HD, our data suggest that no such global disruption occurs in models of SBMA; rather, AR-specific mechanisms, including reduced phosphorylation at Serine 650, are likely responsible for the impaired nuclear export of polyQ-expanded AR.
Plant microbiome-dependent immune enhancing action of Echinacea purpurea is enhanced by soil organic matter content
Authors: Haron Mona H. , Tyler Heather L. , Chandra Suman , Moraes Rita M. , Jackson Colin R. , Pugh Nirmal D. , Pasco David S. 
Published: January 2019

AbstractWe previously demonstrated that extracts from Echinacea purpurea material varied substantially in their ability to activate macrophages in vitro and that this variation was due to differences in their content of bacterial components. The purpose of the current study was to identify soil conditions (organic matter, nitrogen, and moisture content) that alter the macrophage activation potential of E. purpurea and determine whether these changes in activity correspond to shifts in the plant-associated microbiome. Increased levels of soil organic matter significantly enhanced macrophage activation exhibited by the root extracts of E. purpurea (p < 0.0001). A change in soil organic matter content from 5.6% to 67.4% led to a 4.2-fold increase in the macrophage activation potential of extracts from E. purpurea. Bacterial communities also differed significantly between root materials cultivated in soils with different levels of organic matter (p < 0.001). These results indicate that the level of soil organic matter is an agricultural factor that can alter the bacterial microbiome, and thereby the activity, of E. purpurea roots. Since ingestion of bacterial preparation (e.g., probiotics) is reported to impact human health, it is likely that the medicinal value of Echinacea is influenced by cultivation conditions that alter its associated bacterial community.