bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geophysical Constraints on the Crustal Architecture of the Transtensional Warm Springs Valley Fault Zone, Northern Walker Lane, Western Nevada, USA
Authors: Briggs Rich W. , Stephenson William J. , McBride John H. , Odum Jackson K. , Reitman Nadine G. , Gold Ryan D. 
Published: October 2021

AbstractThe Walker Lane is a zone of distributed transtension where normal faults are overprinted by strike‐slip motion. We use two newly acquired, high‐resolution seismic reflection profiles and a reprocessed Consortium for Continental Reflection Profiling (COCORP) deep crustal reflection profile to assess the subsurface geometry of the Holocene‐active, transtensional Warm Springs Valley fault zone (WSVFZ) near Reno, Nevada, USA. Our multiscale observations extend to 12 km depth and suggest that the WSVFZ is more complex in the subsurface than implied by late Pleistocene surface fault traces. Two 4‐km‐long high‐resolution profiles image to a depth of ∼2 km and reveal moderately dipping reflections and truncations, some of which project to mapped scarps formed in late Pleistocene surfaces. The shallow lines are collocated with COCORP profile NV 08 along ∼40°N latitude. Reanalysis of the COCORP data reveals previously unidentified coherent reflections to a depth of ∼12 km and a previously mapped ∼30° west‐dipping fault at 8–12 km. From these seismic profiles, the WSVFZ is not a simple, subvertical fault zone extending through the entire seismogenic crust. Instead, the reflections are consistent with a zone of steeply and moderately dipping faults that simplify and steepen with depth before intersecting a mid‐crustal, low‐angle (∼25–30°) fault. The complex fault geometry of the WSVFZ implies that crustal shear is accommodated by a mix of dipping and subvertical faults in the transtensional northern Walker Lane. If so, transtensional fault zones may present challenges to paleoseismic and geodetic studies and require careful treatment when included in seismic hazard analyses.
A Numerical Analysis of Six Physics‐Dynamics Coupling Schemes for Atmospheric Models
Authors: Ubbiali Stefano , Schär Christoph , Schlemmer Linda , Schulthess Thomas C. 
Published: October 2021

AbstractSix strategies to couple the dynamical core with physical parameterizations in atmospheric models are analyzed from a numerical perspective. Thanks to a suitably designed theoretical framework featuring a high level of abstraction, the truncation error analysis and the linear stability study are carried out under weak assumptions. Indeed, second‐order conditions are derived which are not influenced either by the specific formulation of the governing equations, nor by the number of parameterizations, nor by the structural design and implementation details of the time‐stepping methods. The theoretical findings are verified on two idealized test beds. Particularly, a hydrostatic model in isentropic coordinates is used for vertical slice simulations of a moist airflow past an isolated mountain. Self‐convergence tests show that the sensitivity of the prognostic variables to the coupling scheme may vary. For those variables (e.g., momentum) whose evolution is mainly driven by the dry dynamics, the truncation error associated with the dynamical core dominates and hides the error due to the coupling. In contrast, the coupling error of moist variables (e.g., the precipitation rate) emerges gradually as the spatio‐temporal resolution increases. Eventually, each coupling scheme tends toward the formal order of accuracy, upon a careful treatment of the grid cell condensation. Indeed, the well‐established saturation adjustment may cap the convergence rate to first order. A prognostic formulation of the condensation and evaporation process is derived from first principles. This solution is shown effective to alleviate the convergence issues in our experiments. Potential implications for a complete forecasting system are discussed.
Late Quaternary Abrupt Climate Change in the Tropics and Sub‐Tropics: The Continental Signal of Tropical Hydroclimatic Events (THEs)
Authors: Bradley Raymond S. , Diaz Henry F. 
Published: October 2021

AbstractTropical hydroclimatic events, characterized by extreme regional rainfall anomalies, were a recurrent feature of marine isotope stages 2–4 and involved some of the most abrupt and dramatic climatic changes in the late Quaternary. These anomalies were pervasive throughout the tropics and resulted from the southward displacement of the Hadley circulation and the Intertropical Convergence Zone (ITCZ) and its associated convective rainfall, modulated by regional factors. Lake sediments, stalagmites, and offshore marine sediments that integrate inland continental conditions provide a comprehensive record of these changes over the past ∼70,000 yr. Vast areas experienced severe drought while other areas recorded greatly increased rainfall. Within the uncertainties of dating, these tropical rainfall anomalies occurred very close in time (±102–103 yr) to the deposition of North Atlantic ice‐rafted debris (IRD) that defines Heinrich events (HEs). The IRD record is a good proxy for the amount and distribution of additional freshwater forcing which was necessary to bring about a drastic reduction in the Atlantic Meridional Overturning Circulation (AMOC) strength during each HE. As a consequence of this reduction in AMOC and an abrupt expansion in the area of sea‐ice, cooling of the North Atlantic and adjacent continents took place, with a rapid atmospheric response involving the southward displacement of the ITCZ and associated rainfall belts. The climatic consequences of this large‐scale change in the Hadley circulation, modulated by regional factors, is clearly recorded throughout the tropics as a series of abrupt and extreme hydroclimatic events. Some of the physical mechanisms that may have played a role in those changes are discussed.
Pareto Optimality and Compromise for Environmental Water Management
Authors: Null Sarah E. , Olivares Marcelo A. , Cordera Felipe , Lund Jay R. 
Published: October 2021

AbstractWater management usually considers economic and ecological objectives, and involves tradeoffs, conflicts, compromise, and cooperation among objectives. Pareto optimality often is championed in water management, but its relationships with the mathematical representation of objectives, and implications of tradeoffs for Pareto optimal decisions, are rarely examined. We evaluate the mathematical properties of optimized tradeoffs to identify promising regions for compromise, suggest strategies for reducing conflicts, and better understand whether decision‐makers are more or less likely to cooperate on environmental water allocations. Cooperation and compromise among objectives can be easier when tradeoff curves are concave and more adversarial when tradeoff curves are convex. “Knees,” or areas with maximum curvature, bulges, or breakpoints in concave Pareto frontiers, suggest more promising areas for compromise. Evaluating the shape of Pareto curves based on each objective's performance function can screen for the existence of knees amenable to compromise. We explore water management and restorations actions that improve and shift the location and prominence of knees in concave Pareto frontiers. Connecting river habitats and other non‐flow management actions may add knees on locally concave regions of Pareto frontiers. Managing multiple streams regionally, rather than individually, can sometimes turn convex local tradeoffs into concave regional tradeoffs more amenable to compromise. Overall, this analysis provides a deep investigation of how the shape of tradeoffs influences the range and promise of decisions to improve performance, and illustrates that management actions may encourage cooperation and reduce conflict.
New Paleointensity Data Suggest Possible Phanerozoic‐Type Paleomagnetic Variations in the Precambrian
Authors: Lloyd Simon J. , Biggin Andrew J. , Li Zheng‐Xiang 
Published: October 2021

AbstractThe state of the geomagnetic field throughout the Precambrian era is largely unknown. Approximately 8% of global paleointensity records account for ∼4 billion years of Earth history. Despite this severe sparsity, the data are used to constrain models that predict the timing of significant deep earth events such as inner core nucleation. This carries with it the assumption that the Precambrian paleomagnetic field was less variable when compared to the Phanerozoic, or at least that the sparse data can be averaged to accurately represent a particular time period. This study reports new paleointensities from the West Australian Craton at 755 Ma (the Mundine Wells dyke swarm) and 1,070 Ma (the Bangemall Sills); both of which occurred within ∼30 Ma from times at which extremely weak and anomalously strong fields, respectively, have been reported. Virtual dipole moments of 6.3 ± 0.1 Am2 × 1022 and 1.8 ± 1.2 Am2 × 1022 have been obtained from the two suites of mafic rock units which are substantially different to the previous measurements for the two respective ages. The findings suggest that field variability over tens of Myrs in the Precambrian was greater than has previously been assumed. This is supported by comparisons of paleosecular variation and distributions of virtual dipole moments. If variability in the Precambrian field is similar to that observed in the Phanerozoic, spatial or temporal anomalies may introduce significant bias to statistical analyses and model constraints, implying that caution should be employed in the interpretation of the Precambrian dipole moment records.
Pliocene to Early Pleistocene Drainage Reorganization in Eastern Tibet Inferred From Detrital Zircons
Authors: Zhao Xudong , Zhang Huiping , Tao Yaling , Wang Ying , Pang Jianzhang , Ma Yan , Zhang Jiawei , Ma Zifa , Xiong Jianguo 
Published: October 2021

AbstractThe drainage evolution in eastern Tibet during the India‐Eurasia collision has attracted considerable attention because of its critical link to topographic development and plateau growth, but the discussion still persists. In the present study, new and published detrital zircon U‐Pb ages are integrated from Pliocene‐Early Pleistocene Xigeda Formation (XGD) and modern river sands to decipher the paleo‐drainage evolution in eastern Tibet. The results confirm the eastward flow of the Jinsha River before the Pliocene, but the drainage patterns of its major tributaries (Dadu, Yalong, and Anning) in the Pliocene, differ from the modern ones. In conjunction with the previously documented fluvial incision in eastern Tibet, we interpreted that the excavation of the Paleo‐Xigeda lake in Early Pleistocene time initiated and accentuated incision of the Jinsha River and its major tributaries. This led to drainage reorganization and the modern river pattern establishment in eastern Tibet.
Robust Evaluation of ENSO in Climate Models: How Many Ensemble Members Are Needed?
Authors: Lee Jiwoo , Planton Yann Y. , Gleckler Peter J. , Sperber Kenneth R. , Guilyardi Eric , Wittenberg Andrew T. , McPhaden Michael J. , Pallotta Giuliana 
Published: October 2021

AbstractLarge ensembles of model simulations require considerable resources, and thus defining an appropriate ensemble size for a particular application is an important experimental design criterion. We estimate the ensemble size (N) needed to assess a model’s ability to capture observed El Niño‐Southern Oscillation (ENSO) behavior by utilizing the recently developed International CLIVAR ENSO Metrics Package. Using the larger ensembles available from CMIP6 and the US CLIVAR Large Ensemble Working Group, we find that larger ensembles are needed to robustly capture baseline ENSO characteristics (N > 50) and physical processes (N > 50) than the background climatology (N ≥ 12) and remote ENSO teleconnections (N ≥ 6). While these results vary somewhat across metrics and models, our study quantifies how larger ensembles are required to robustly evaluate simulated ENSO behavior, thereby providing some guidance for the design of model ensembles.
Seismic Evidence of Mid‐Mantle Water Transport Beneath the Yellowstone Region
Authors: Frazer William D. , Park Jeffrey 
Published: October 2021

AbstractEarth's mantle transition zone (MTZ) is a possible global water reservoir and may be responsible for long‐term (∼100 Ma) ocean‐mass regulation. Estimates of water capacities in MTZ minerals are ∼1 wt%, far greater than that of rocks of the surrounding mantle. When water‐rich material is displaced from the MTZ, partial melting occurs, generating a sharp reduction in seismic velocities detectable with seismic receiver functions (RFs). We estimated RFs for the MTZ beneath the Yellowstone region using earthquakes recorded by ∼200 stations of the Earthscope Transportable Array. We found many LVZs both above and below the MTZ, consistent with water release upon phase transformation of hydrated MTZ rock into upper‐ and lower‐mantle mineral assemblages with low water capacities. The locations of LVZs are consistent with mid‐mantle flow induced by descent of a Farallon‐slab fragment and ascent of the deeply rooted Yellowstone plume as imaged by seismic tomography.
The Effect of Authigenic Clays on Fault Zone Permeability
Authors: Farrell N. J. C. , Debenham N. , Wilson L. , Wilson M. J. , Healy D. , King R. C. , Holford S. P. , Taylor C. W. 
Published: October 2021

AbstractClays are understood to form the majority of fluid‐flow barriers in faulted reservoirs and numerous fault gouge and fault seal studies have quantified the volumes of smeared and abraded clays create fluid‐flow barriers along fault surfaces. However, clay‐related permeability adjacent to the fault surface, including in the fault damage zone, has largely been neglected. Previous studies have shown the morphology and distribution of unfaulted authigenic clays, and not just clay volume, exert a significant control on the magnitude of permeability. However, fault‐related studies have neither characterized deformed authigenic clays nor addressed their influence on fluid‐flow. In this study laboratory permeabilities of faulted, authigenic clay bearing sandstones sampled from the Otway basin (Australia) and the Orcadian basin (UK) present trends which; (a) do not correspond to expected patterns of fluid‐flow in faulted clay‐bearing sandstones and, (b) cannot be explained using published models of permeability related to changing clay volume. Microscopic analysis shows that faulting has disaggregated authigenic clays and, similarly to framework grain deformation, comminuted and sheared clay grains. However, instead of impeding fluid‐flow, analysis of pore networks (using mercury injection porosimetry) showed that faulting of authigenic clays has increased pore connectivity, contributing to increased magnitude of permeability and development of permeability anisotropy. Contrary to published results of faulting and fluid‐flow in impure sandstones, our results show that fault related processes involving the formation of clays in the fault zone can increase permeability and reduce the capillary threshold pressures of fault rocks relative to the unfaulted host rock.
CAPE Threshold for Lightning Over the Tropical Ocean
Authors: Cheng Wei‐Yi , Kim Daehyun , Holzworth Robert H. 
Published: October 2021

AbstractWe investigate the relationship between convective available potential energy (CAPE), precipitation, the number and size of storms and overshooting tops, and lightning stroke density (f) over the Central America region. While f increases almost linearly with CAPE1/2 over land, f is nearly muted over the ocean when CAPE is small. In the high‐CAPE regime, on the contrary, oceanic storms produce as many lightning flashes as land storms. We show that individual oceanic storms are smaller and contain fewer overshooting tops compared to land storms, although the difference exists across low‐ and high‐CAPE regimes. While f increases as individual storm size increases, the storm size required to produce lightning appears to be disproportionately high in the low‐CAPE regime, likely due to the stronger entrainment effect. The entrainment effect on f in the low‐CAPE regime appears to be much weaker over land. Applying the CAPE threshold for lightning over the ocean to the CAPE‐based lightning parameterization scheme of Romps et al. (2014), https://doi.org/10.1126/science.1259100 improves its performance, in particular, at representing the land‐sea contrast in f.
Climate Process Team: Improvement of Ocean Component of NOAA Climate Forecast System Relevant to Madden‐Julian Oscillation Simulations
Authors: Shinoda Toshiaki , Pei Suyang , Wang Wanqiu , Fu Joshua X. , Lien Ren‐Chieh , Seo Hyodae , Soloviev Alexander 
Published: October 2021

AbstractGiven the increasing attention in forecasting weather and climate on the subseasonal time scale in recent years, National Oceanic and Atmospheric Administration (NOAA) announced to support Climate Process Teams (CPTs) which aim to improve the Madden‐Julian Oscillation (MJO) prediction by NOAA’s global forecasting models. Our team supported by this CPT program focuses primarily on the improvement of upper ocean mixing parameterization and air‐sea fluxes in the NOAA Climate Forecast System (CFS). Major improvement includes the increase of the vertical resolution in the upper ocean and the implementation of General Ocean Turbulence Model (GOTM) in CFS. In addition to existing mixing schemes in GOTM, a newly developed scheme based on observations in the tropical ocean, with further modifications, has been included. A better performance of ocean component is demonstrated through one‐dimensional ocean model and ocean general circulation model simulations validated by the comparison with in‐situ observations. These include a large sea surface temperature (SST) diurnal cycle during the MJO suppressed phase, intraseasonal SST variations associated with the MJO, ocean response to atmospheric cold pools, and deep cycle turbulence. Impact of the high‐vertical resolution of ocean component on CFS simulation of MJO‐associated ocean temperature variations is evident. Also, the magnitude of SST changes caused by high‐resolution ocean component is sufficient to influence the skill of MJO prediction by CFS.
Application of Deep Learning for Imaging‐Based Stream Gaging
Authors: Vanden Boomen Ryan L. , Yu Zeyun , Liao Qian 
Published: October 2021

AbstractStream gages are critically important for measuring stream flow in water resources management. Stream gages monitor and record flow and water stage within some water body. The United States Geological Survey maintains a network of stream gages across the country. Many of these sites are also equipped with webcams to gather real‐time river information, especially in flood flows. Remotely measuring flow discharge using particle image tracking has been researched intensively. This study demonstrates a process for training a deep neural network that will utilize the webcam and stream gage data to generate a water stage prediction based on webcam captured river images. This study presents the experiments on stream gages located at the Clear Creek in Iowa, Auglaize River in Ohio, and Milwaukee River in Wisconsin. The process outlined utilizes transfer learning and well‐known image classification models as a basis for a generalized river stage regression model. Across the training, validation, and deployment experiments, the developed process shows success in creating an accurate model for these testing sites of different perspective settings. The results of this study show confidence in future studies utilizing ground‐level remote stream gaging with Machine Learning‐enabled image regression.
A meta-analysis of effectiveness of real-world studies of antipsychotics in schizophrenia: Are the results consistent with the findings of randomized controlled trials?
Authors: Katona Lajos , Bitter István , Czobor Pál 
Published: October 2021

AbstractRandomized controlled trials (RCTs) have been considered as gold standard for establishing the efficacy and safety of investigational new drugs; nonetheless, the generalizability of their findings has been questioned. To address this issue, an increasing number of naturalistic studies and real-world database analyses have been conducted. The question of how much information from these two approaches is congruent or discrepant with each other is of great importance for the clinical practice. To answer this question, we focused on data from the antipsychotic (AP) treatment of schizophrenia. Our aim was two-fold: to conduct a meta-analysis of real-world studies (RWS), and to compare the results of RWS meta-analysis with previously published meta-analyses of RCTs. The principal measure of effectiveness was all-cause treatment discontinuation for both RWS and RCTs (when not available, then drop out for RCTs). We included publications for 8 selected APs (oral formulations of amisulpride, aripiprazole, clozapine, haloperidol, olanzapine, quetiapine, risperidone, and long-acting injectable (LAI) risperidone). We identified 11 RWS and 7 RCT meta-analyses for inclusion. Our results indicated that the RWS yielded statistically conclusive and consistent findings across individual investigations. For the overwhelming majority of the comparisons where both RWS and RCT meta-analyses were available, there was good congruency between the RWS and the RCT results. Our results support that RCTs, despite their limitations, provide evidence which is generalizable to real-world settings. This is an important finding for both regulators and clinicians. RWS can provide guidance for situations where no evidence is available from double-blind clinical trials.
Isotope data from amino acids indicate Darwin’s ground sloth was not an herbivore
Authors: Tejada Julia V. , Flynn John J. , MacPhee Ross , O’Connell Tamsin C. , Cerling Thure E. , Bermudez Lizette , Capuñay Carmen , Wallsgrove Natalie , Popp Brian N. 
Published: October 2021

AbstractFossil sloths are regarded as obligate herbivores for reasons including peculiarities of their craniodental morphology and that all living sloths feed exclusively on plants. We challenge this view based on isotopic analyses of nitrogen of specific amino acids, which show that Darwin’s ground sloth Mylodon darwinii was an opportunistic omnivore. This direct evidence of omnivory in an ancient sloth requires reevaluation of the ecological structure of South American Cenozoic mammalian communities, as sloths represented a major component of these ecosystems across the past 34 Myr. Furthermore, by analyzing modern mammals with known diets, we provide a basis for reliable interpretation of nitrogen isotopes of amino acids of fossils. We argue that a widely used equation to determine trophic position is unnecessary, and that the relative isotopic values of the amino acids glutamate and phenylalanine alone permit reliable reconstructions of trophic positions of extant and extinct mammals.
Sum‐rate optimization scheme for time‐varying distributed MU‐MIMO systems
Authors: Xie Shaoguo , Ai Liefu 
Published: October 2021

AbstractSum‐rate optimization problem is a key issue in a time‐varying multi‐user multi‐input multi‐output (MU‐MIMO) distributed antenna system. Channel precoding matrix is the key technology in the achievable sum‐rate optimization problem. In this paper, two algorithms are proposed to solve the achievable sum‐rate optimization problem for a time‐varying MU‐MIMO distributed antenna system, namely one‐dimensional search algorithm (OSA) and cyclic MMSE (Minimum Mean Square Error) search algorithm (CMSA). In order to design the channel precoding matrix for the achievable sum‐rate optimization, a one‐dimensional search algorithm is proposed in the time‐varying MU‐MIMO distributed antenna system. For the problem with a large amount of computation in OSA, a cyclic MMSE search algorithm is proposed in the time‐varying MU‐MIMO distributed antenna system. Simulation results show that the proposed algorithms can effectively improve the sum‐rate compared to other algorithms. Simulation results also show that OSA is superior to CMSA in the sum‐rate, and the channel state information (CSI) coefficient has little effect on OSA and CMSA.