bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can Convection‐Permitting Modeling Provide Decent Precipitation for Offline High‐Resolution Snowpack Simulations Over Mountains?
Authors: He Cenlin , Chen Fei , Barlage Michael , Liu Changhai , Newman Andrew , Tang Wenfu , Ikeda Kyoko , Rasmussen Roy 
Published: November 2019

AbstractAccurate precipitation estimates are critical to simulating seasonal snowpack evolution. We conduct and evaluate high‐resolution (4‐km) snowpack simulations over the western United States (WUS) mountains in Water Year 2013 using the Noah with multi‐parameterization (Noah‐MP) land surface model driven by precipitation forcing from convection‐permitting (4‐km) Weather Research and Forecasting (WRF) modeling and four widely used high‐resolution datasets that are derived from statistical interpolation based on in situ measurements. Substantial differences in the precipitation amount among these five datasets, particularly over the western and northern portions of WUS mountains, significantly affect simulated snow water equivalent (SWE) and snow depth (SD) but have relatively limited effects on snow cover fraction (SCF) and surface albedo. WRF generally captures observed precipitation patterns and results in an overall best‐performed SWE and SD in the western and northern portions of WUS mountains, where the statistically interpolated datasets lead to underpredicted precipitation, SWE, and SD. Over the interior WUS mountains, all the datasets consistently underestimate precipitation, causing significant negative biases in SWE and SD, among which the results driven by the WRF precipitation show an average performance. Further analysis reveals systematic positive biases in SCF and surface albedo across the WUS mountains, with similar bias patterns and magnitudes for simulations driven by different precipitation datasets, suggesting an urgent need to improve the Noah‐MP snowpack physics. This study highlights that convection‐permitting modeling with proper configurations can have added values in providing decent precipitation for high‐resolution snowpack simulations over the WUS mountains in a typical ENSO‐neutral year, particularly over observation‐scarce regions.
The Primary Convective Pathway for Observed Wildfire Emissions in the Upper Troposphere and Lower Stratosphere: A Targeted Reinterpretation
Authors: Fromm Michael , Peterson David , Di Girolamo Larry 
Published: November 2019

AbstractThe literature—spanning several recent decades—describes numerous attempts to characterize the efficacy of cumulonimbus “Cb” convection as a pollutant pathway connecting the planetary BL to the upper troposphere and lower stratosphere (UTLS). The relatively new discovery of wildfires triggering deep convection and Cb formation, referred to as pyrocumulonimbus “pyroCb,” has provided a new convective candidate for examination. Previous studies have shown that the pyroCb pathway offers a reinterpretation of supposed volcanic aerosol layers observed in the stratosphere. The community now questions whether this relatively unappreciated phenomenon has been overlooked or imprecisely characterized in published analyses of observed UTLS biomass burning constituents attributed to traditional convection, such as individual Cbs or larger mesoscale convective systems. Here we show that on at least two occasions, a reinterpretation of the literature is required. Both are in the context of coordinated measurement campaigns in summertime Central and North American domains. We provide a strategic review of prior studies and explore three selected works, wherein the pyroCb naturally explains observations of dramatically strong, remote, and high‐altitude biomass burning pollution. We complete our discussion with the implications for including the pyroCb phenomenon in case studies and assessments of the primary convective pathway for smoke particles to enter the UTLS.
Intraseasonal to Interannual Modulation of Diurnal Precipitation Distribution Over Eastern Africa
Authors: Camberlin Pierre , Gitau Wilson , Kiladis George , Bosire Emily , Pohl Benjamin 
Published: November 2019

AbstractThe modulation of the rainfall diurnal cycle at intraseasonal and interannual time scales is examined using gridded rainfall data over Eastern Africa and the nearby Indian Ocean for the period 1998–2014. Our focus is on the October‐December season which is strongly impacted by both the Madden‐Julian Oscillation (MJO) and the Indian Ocean Dipole Mode (IODM). The effect of the MJO, which is not synchronized across the whole region, is mainly through changes in the amplitude of the diurnal cycle, especially an enhancement of the late afternoon peak in active phases of the MJO. The rainfall phase only shows minor variations between the active and quiescent phases of the MJO, except over the drier regions and the Indian Ocean where the overall diurnal rainfall signal is more uneven. The effect of the positive phase of the IODM (warm western Indian Ocean) on Eastern Africa rainfall is found at any time of the day, but the enhancement is more prominent during the wettest part of the day (generally the afternoon). Substantial changes in the diurnal phase of the rains are found in some land areas away from the coast or from mountain ranges, where the dominant afternoon peak during the negative IODM phase is replaced by a nighttime maximum during the positive phase. Cross‐sections and a cluster analysis of diurnal rainfall patterns over Kenya and southern Somalia suggest that this feature may be associated with the development of longer‐lived rainfall systems propagating inland from the coast during the IODM positive phase.
Understanding the Moisture Variance in Precipitating Shallow Cumulus Convection
Authors: Anurose T. J. , Bašták Ďurán Ivan , Schmidli Juerg , Seifert Axel 
Published: November 2019

AbstractThe impact of precipitation in shallow cumulus convection on the moisture variance and third‐order moments of moisture is investigated with the help of large‐eddy simulations. Three idealized simulations based on the Rain in Cumulus over the Ocean field experiment are analyzed: one nonprecipitating, on a smaller domain, and two precipitating cases, on a larger domain with different initial profiles of moisture. Results show that precipitation and the associated cloud organization lead to increased generation of higher‐order moments (HOM) of moisture compared to the nonprecipitating case. To understand the physical mechanism and the role of individual processes in this increase, budgets of HOM of moisture are studied. Microphysics directly decreases the generation of HOM of moisture, but this effect is not dominant. The gradient production term is identified as the main source term in the HOM budgets. The influence of the gradient production term on moisture variance is further examined separately in cloud active and nonactive regions. The main contribution to the gradient production term comes from the smaller cloud active region because of the stronger moisture flux. Further analyses of the horizontal and vertical cross sections of moisture fluctuations show that the precipitation‐induced downdrafts and updrafts are the main mechanism for the generation of moisture variance. The variance increase is linked to shallow dry downdraft regions with horizontal divergence in the subcloud layer, moist updrafts with horizontal convergence in the bulk cloud layer, and finally wider areas of horizontal divergence in the cloud inversion layer.
Salt Marsh Establishment and Eco‐Engineering Effects in Dynamic Estuaries Determined by Species Growth and Mortality
Authors: Brückner Muriel Z. M. , Schwarz Christian , van Dijk Wout M. , van Oorschot Mijke , Douma Harke , Kleinhans Maarten G. 
Published: November 2019

Growth conditions and eco‐engineering effects of vegetation on local conditions in coastal environments have been extensively studied. However, interactions between salt marsh settling, growth, and mortality as a function of hydromorphology and eco‐engineering lack sufficient understanding to forecast morphological development of dynamic systems. We predict salt marsh establishment with an ecomorphodynamic model that accounts for literature‐based seasonal settling and life‐stage‐dependent growth and mortality of a generic salt marsh species. The model was coupled to a calibrated hydromorphodynamic model of an intertidal bar and, on a coarser grid, to the entire Western Scheldt estuary. To quantify the importance of eco‐engineering effects we compared the dynamic model results to a static model approach. The ecomorphodynamic model reproduces spatial pattern, cover, and growth trends over 15 years. The modeled vegetation cover emerges from the combination of a positive and a new negative eco‐engineering effect: vegetation reduces tidal flow strength facilitating plant survival while the developing salt marsh increases the hydroperiod, which limits large‐scale marsh expansion. The reproduced spatial gradient in vegetation density by our model is strongly correlated to their life‐stages, which underlines the importance of age‐dependence when modeling vegetation and for predictions of the stability of the marsh. Upscaling of the model to the entire estuary on a coarser grid gives implications for grid size‐dependent modeling of hydrodynamics and vegetation. In comparison with static model results, the eco‐engineering effects reduce vegetation cover, showing the importance of vegetation dynamics for predictions of salt marsh growth.
Mechanistic Modeling of Microtopographic Impacts on CO2 and CH4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM‐Microbe Model
Authors: Wang Yihui , Yuan Fengming , Yuan Fenghui , Gu Baohua , Hahn Melanie S. , Torn Margaret S. , Ricciuto Daniel M. , Kumar Jitendra , He Liyuan , Zona Donatella , Lipson David A. , Wagner Robert , Oechel Walter C. , Wullschleger Stan D. , Thornton Peter E. , Xu Xiaofeng 
Published: November 2019

AbstractSpatial heterogeneities in soil hydrology have been confirmed as a key control on CO2 and CH4 fluxes in the Arctic tundra ecosystem. In this study, we applied a mechanistic ecosystem model, CLM‐Microbe, to examine the microtopographic impacts on CO2 and CH4 fluxes across seven landscape types in Utqiaġvik, Alaska: trough, low‐centered polygon (LCP) center, LCP transition, LCP rim, high‐centered polygon (HCP) center, HCP transition, and HCP rim. We first validated the CLM‐Microbe model against static‐chamber measured CO2 and CH4 fluxes in 2013 for three landscape types: trough, LCP center, and LCP rim. Model application showed that low‐elevation and thus wetter landscape types (i.e., trough, transitions, and LCP center) had larger CH4 emissions rates with greater seasonal variations than high‐elevation and drier landscape types (rims and HCP center). Sensitivity analysis indicated that substrate availability for methanogenesis (acetate, CO2 + H2) is the most important factor determining CH4 emission, and vegetation physiological properties largely affect the net ecosystem carbon exchange and ecosystem respiration in Arctic tundra ecosystems. Modeled CH4 emissions for different microtopographic features were upscaled to the eddy covariance (EC) domain with an area‐weighted approach before validation against EC‐measured CH4 fluxes. The model underestimated the EC‐measured CH4 flux by 20% and 25% at daily and hourly time steps, suggesting the importance of the time step in reporting CH4 flux. The strong microtopographic impacts on CO2 and CH4 fluxes call for a model‐data integration framework for better understanding and predicting carbon flux in the highly heterogeneous Arctic landscape.
Understanding Hail in the Earth System
Authors: Allen John T. , Giammanco Ian M. , Kumjian Matthew R. , Jurgen Punge Heinz , Zhang Qinghong , Groenemeijer Pieter , Kunz Michael , Ortega Kiel 
Published: November 2019

AbstractThe processes leading to the development of hail and the distribution of these events worldwide are reviewed. Microphysical and physical characteristics of hail development are described to provide context of the notable gaps in our understanding of what drives hail to grow large, or what determines how it falls to the ground. Distributional characteristics of hail are explored, utilizing both surface observations of hailstones and remotely sensed observational data sets to identify opportunities and needs for new observations. These observational deficiencies contribute to our limited capacity to both forecast hail or its expected size and reduce the effectiveness of using favorable conditions for hail development as a proxy to frequency where observations are unavailable. Given the substantive influences of both climate variability and the changing Earth system on hail, the latest understanding of their contributions to risk are addressed. Applying this understanding of the distribution and physical characteristics of hail, the damage by hail to agriculture and insured property is assessed. Much remains unknown about the processes leading to hail growth and environmental controls on hail occurrence, size, and magnitude, particularly outside of the United States and Europe. A better understanding of the global occurrence of hail is also needed to better anticipate the hazard and associated impacts.
Current pulse shaping technique for low spur fractional‐N phase‐locked loop
Authors: He Dan , Lu Fujian , Wang Dezhi 
Published: November 2019

Current pulse shaping technique is proposed for low spur fractional‐N phase‐locked loop, which is realised by a variable amplitude charge pump (VA‐CP) and a fixed‐position, fixed‐width and variable‐period pulse generator (FFVPG). The current pulse of VA‐CP driven by the FFVPG is shaped to fixed position, fixed width, variable amplitude and variable period for eradicating both reference spurs and fractional spurs. The period of VA‐CP's current pulse is TREF during transient and N1 × TREF during locking status, in which the N1 should be properly set in order to reduce fractional spurs as far as possible and accelerate locking time. The spur performance of the proposed fractional phase‐locked loop is evaluated by analysing the spectrum of tuning voltage when reference frequency is 20 MHz and division ratio is 120.13. Spectre based simulation results show the reference spurs at integer multiplies of 20 MHz is eradicated, and the fractional spurs at 10 MHz and the other fractional frequencies are 19.67 dB and much less than that with the existing technique, which verify the feasibility of this study.
Enhancement of wind speed using converging duct for cooling off‐grid mast‐mounted flat solar PV panels to improve its power generation
Authors: Subramanian Rajkumar , Murugesan Chandrasekar , Tamilkolundu Senthilkumar , Jaganath Dhobarathy 
Published: November 2019

The potential of wind speed for cooling a mast‐mounted solar photovoltaic (PV) panel is tapped by placing a converging duct in the windward direction of the PV panel mounting. Owing to this arrangement, the wind speed beneath the PV panel is increased, which resulted in decrease of the operating temperature of PV panel and increase in PV electrical power generation. The wind speed is increased by a factor of 1.5, which reduced the temperature of PV panel by 2–3°C and increased the electrical output power by 0.7 W. Correlations in terms of ambient temperature, solar irradiation and wind velocity were developed for predicting the PV panel temperature and were validated with the experimental values.
Two‐dimensional composite (BiOCl/GO/MOF‐5) by ultrasonic‐assisted solvothermal synthesis with enhanced photocatalytic activity
Authors: Zhai Boyin , Chen Ying , Li Jing , Liang Yuning 
Published: November 2019

In this work, a novel two‐dimensional photocatalyst (BiOCl/GO/MOF‐5) was successfully developed by ultrasonic‐assisted solvothermal method. X‐ray diffraction, scanning electron microscope, Brunauer–Emmett–Teller, UV–visible diffuse reflectance spectrum, photoluminescence and NH3‐TPD were employed to characterise its unique structure and property. The results show that the specific surface area of the two‐dimensional composite (205.1 mg2 ·g−1) is significantly higher than single BiOCl (3.14 mg2 ·g−1), which provide much more active site for the photocatalystic process. Also the photocatalytic efficiency could reach to 90.6% that is much higher than pure BiOCl. This could be attributed to the effective electrons‐holes separations and proper bandgap to enhance photocatalytic performance. At the same time, the formation mechanism and the possible photocatalytic mechanism of photocatalyst were proposed.
The young stellar content of the giant H II regions M 8, G333.6−0.2, and NGC 6357 with VLT/KMOS
Authors: Ramírez-Tannus M. C. , Poorta J. , Bik A. , Kaper L. , de Koter A. , De Ridder J. , Beuther H. , Brandner W. , Davies B. , Gennaro M. , Guo D. , Henning T. , Linz H. , Naylor T. , Pasquali A. , Ramírez-Agudelo O. H. , Sana H. 
Published: November 2019

Context.The identification and characterisation of populations of young massive stars in (giant) H IIregions provides important constraints on (i) the formation process of massive stars and their early feedback on the environment, and (ii) the initial conditions for population synthesis models predicting the evolution of ensembles of stars.Aims.We identify and characterise the stellar populations of the following young giant H IIregions: M 8, G333.6−0.2, and NGC 6357.Methods.We have acquiredH- andK-band spectra of around 200 stars using theK-band Multi Object Spectrograph on the ESO Very Large Telescope. The targets for M 8 and NGC 6357 were selected from the Massive Young Star-Forming Complex Study in Infrared and X-ray (MYStIX), which combines X-ray observations with near-infrared (NIR) and mid-infrared data. For G333.6−0.2, the sample selection is based on the NIR colours combined with X-ray data. We introduce an automatic spectral classification method in order to obtain temperatures and luminosities for the observed stars. We analysed the stellar populations using their photometric, astrometric, and spectroscopic properties and compared the position of the stars in the Hertzprung-Russell diagram with stellar evolution models to constrain their ages and mass ranges.Results.We confirm the presence of candidate ionising sources in the three regions and report new ones, including the first spectroscopically identified O stars in G333.6−0.2. In M 8 and NGC 6357, two populations are identified: (i) OB main-sequence stars (M >  5M⊙) and (ii) pre-main sequence stars (M ≈ 0.5 − 5 M⊙). The ages of the clusters are ∼1−3 Myr, < 3 Myr, and ∼0.5−3 Myr for M 8, G333.6−0.2, and NGC 6357, respectively. We show that MYStIX selected targets have > 90% probability of being members of the H IIregion, whereas a selection based on NIR colours leads to a membership probability of only ∼70%.
The 400-m Front Crawl Test: Energetic and 3D Kinematical Analyses
Authors: Correia Ricardo de Assis , Feitosa Wellington Gomes , Figueiredo Pedro , Papoti Marcelo , Castro Flávio Antonio de Souza 
Published: November 2019

AbstractThe aim of the study was to verify the relative contributions of energetic and kinematic parameters to the performance in 400-m front crawl test. Fourteen middle-distance swimmers participated in the study. Oxygen consumption was measured directly and blood samples were collected to assay lactate concentration. Both oxygen consumption and lactate concentration were used to calculate the: (i) overall energy expenditure, (ii) anaerobic (alactic and lactic) and (iii) aerobic contributions. The mean centre of mass speed and intracycle velocity variation were determined through three-dimensional kinematic analysis. Mean completion time was 315.64±26.91s. Energetic contributions were as follows: 6.1±0.28% from alactic anaerobic metabolism, 5.9±0.63% from anaerobic lactic and 87.8±0.88% from aerobic. Mean intracycle velocity variation was 0.14±0.03. The results indicated that performance of 400-m test relies predominantly on aerobic power. Parameters such as lactate, mean speed, anaerobic lactic and alactic (kW) correlated with performance of 400-m test (p <0.05). Multiple linear regressions indicated that mean centre of mass speed and anaerobic alactic (kW) determined the 400-m test performance (R2=0.92). Even though the T400 is characterized by aerobic metabolism, the anaerobic alactic component cannot be negligible at this competition level.
E-Zigarettenkonsum und späterer Konsum konventioneller Zigaretten
Authors: Hansen J. , Janssen J. , Morgenstern M. , Hanewinkel R. 
Published: November 2019

Zusammenfassung
Ziel Es sollte untersucht werden, ob der vorherige E-Zigarettenkonsum das spätere Probieren konventioneller Zigaretten vorhersagt.
Methode Im Schuljahr 2016/2017 nahmen in den Bundesländern Baden-Württemberg, Mecklenburg-Vorpommern, Nordrhein-Westfalen, Rheinland-Pfalz, Schleswig-Holstein und Sachsen 2388 Kinder und Jugendliche, die nie zuvor konventionelle Zigaretten geraucht haben, über 2 Jahre an einer Fragebogenstudie teil (mittleres Alter = 11,8 Jahre, SD = 1,21; 49,6 % weiblich).
Ergebnisse Zur Eingangserhebung gaben 85 Schülerinnen und Schüler (3,6 %) an, schon einmal E-Zigaretten probiert zu haben. Im Beobachtungszeitraum begannen 430 der ehemals nie rauchenden Jugendlichen (18,0 %) mit konventionellen Zigaretten zu experimentieren. Auch nach statistischer Kontrolle von Alter, Geschlecht, Migrationshintergrund, „Sensation Seeking“, subjektiver Schulleistung, Alkoholkonsum, sozioökonomischem Status und Schulart war das relative Risiko für das Experimentieren bei Nutzern von E-Zigaretten um 85 % erhöht (adjustiertes relatives Risiko = 1,85, 95 % KI [1, 34 – 2,56]). Weiterführende Analysen zeigten, dass das Risiko insbesondere für Jugendliche mit niedrigem „Sensation Seeking“ erhöht war.
Schlussfolgerungen Jugendliche experimentierten häufiger mit konventionellen Zigaretten, wenn sie zuvor E-Zigaretten konsumiert hatten. Diese Assoziation scheint stärker für Jugendliche zu sein, die ein generell niedrigeres Risiko haben, mit dem Rauchen zu beginnen.
Idiopathic Hypertrophic Pyloric Stenosis with Complete Ladd's Band: A Rare Association
Authors: Abo Elyazeed Ahmed M. , Shalaby Mohamed M. , Awad Mohamed M. , Effat AbdelMotaleb M. , Abdella Ahmed E. , Shehata Sherif Mohamed 
Published: November 2019

AbstractA male infant aged 45 days presented with projectile nonbilious vomiting for 2 weeks. Ultrasound showed picture of idiopathic hypertrophic pyloric stenosis. Laparoscopic pyloromyotomy was done, but postoperative vomiting that was mainly nonbilious continued without improvement. After 4 days of persistent vomiting, laparoscopic exploration was done and complete pyloromyotomy was confirmed and malrotation with complete Ladd's band was found, then case converted to open laparotomy and Ladd's procedure was done. Postoperatively, vomiting stopped completely and baby began gradual feeding till reaching full feed. Despite that the presentation of concurrent Idiopathic Hypertrophic Pyloric Stenosis with malrotation is extremely rare; a formal laparoscopic abdominal exploration should be done as the first step before proceeding to pyloromyotomy.
The Irreducible Knee Dislocation
Authors: Malik Shahbaz S. , MacDonald Peter B. 
Published: November 2019

AbstractIrreducible knee dislocations are a small subset of acute knee dislocations and are extremely rare. The most common type of irreducible knee dislocation is posterolateral, which can be challenging to diagnose both clinically and on plain radiographs. Vascular injury is uncommon and closed reduction is seldom possible due to medial femoral condyle buttonholing through soft tissues requiring open or arthroscopic reduction. Ligament injuries mostly include medial collateral ligament, anterior cruciate ligament, and posterior cruciate ligament. Literature has numerous case reports with a couple of small series giving short- to mid-term outcomes of posterolateral knee dislocations. There is, however, no consensus on management of ligament injuries with case reports showing good outcomes in early or delayed ligament reconstruction. This article sheds light on previous case reports and describes how to identify irreducible knee dislocations and provides an algorithm on how to manage ligament injuries in posterolateral dislocations.