bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE SEQUEL: THE FIFTEENTH AMENDMENT, THE NINETEENTH AMENDMENT, AND SOUTHERN BLACK WOMEN'S STRUGGLE TO VOTE
Authors: Gidlow Liette 
Published: July 2018

This essay reframes both the woman suffrage narrative and narratives of African American voting rights struggles by focusing on the experiences of southern African American women between the 1870s and the 1920s. It argues that the Fifteenth Amendment remained central to their suffrage strategy long after the failure of the “New Departure” to win court sanction caused white suffragists to abandon it. As white supremacists in the South worked at the turn of the century to disfranchise black men, leading African American suffragists such as Mary Church Terrell, Gertrude Bustill Mossell, and Adella Hunt Logan called for the enforcement of the Fourteenth and Fifteenth Amendments as well as the enfranchisement of black women. After the federal woman suffrage amendment was ratified in 1920, many southern African American women encountered the same barriers to voting—obstructionist tactics, threats, and violence—that black men had faced a generation earlier. In short, for aspiring African American voters in the South, the failure of the Nineteenth Amendment to secure voting rights for black women constituted a sad sequel to the failure of the Fifteenth Amendment to secure voting rights for black men.This interpretation offers three significant interventions. It pairs the Reconstruction-era Amendments with the Nineteenth Amendment, recognizing their shared focus on voting rights. It connects the voting rights struggles of southern African Americans across genders and generations. Finally, it finds that, for some women, the canonical “century of struggle” for voting rights continued long after the Nineteenth Amendment was ratified.
Sunspots Areas and Heliographic Positions on the Drawings Made by Galileo Galilei in 1612
Authors: Vokhmyanin Mikhail V. , Zolotova Nadezhda V. 
Published: July 2018

AbstractIn 1612, Galileo Galilei made very accurate drawings of the solar disk. Currently, 47 of them are in the open access: 9 in May 3 – 11, 35 in June and July, and 3 in late August. Unfortunately, reports have not provided the clock time, which results in uncertainty of sunspots heliographic coordinates. In the present study, we determine the exact time of the drawings by comparing the positions of the same spots from day to day. The time of the observations, which varies from 12 to 16 UT, gives us the direction of the solar rotation axis and the position of the helioequator. Unlike the spots drawn by Christopher Scheiner in 1611 – 1612, none of the analyzed spots lies within the helioequator. This confirms the quality of the Galileo’s drawings.
Testing Models of the Fast Solar Wind using Spectroscopic and In Situ Observations
Authors: Fludra Andrzej , Landi Enrico 
Published: July 2018

AbstractWe present a new technique to study joint observations of EUV spectral line intensities and in situ charge states of the fast solar wind. We solve the time-dependent equation for ionization and recombination for a chosen element and calculate the charge state evolution along the open magnetic fields for elements such as C, O, Ne, Mg, Si and Fe. Comparing predicted spectral lines intensities above the limb and in situ charge states to observations from SOHO/SUMER and Ulysses/SWICS, we test how well the modelled thermodynamic parameters of the solar wind reproduce observations. We outline the application of this method to Solar Orbiter data.
Prospects for Modeling and Forecasting SEP Events with ENLIL and SEPMOD
Authors: Luhmann J. G. , Mays M. L. , Odstrcil D. , Li Yan , Bain H. , Lee C. O. , Cohen C. M. S. , Mewaldt R. A. , Leske R. A. , Futaana Y. 
Published: July 2018

AbstractOne view of major Solar Energetic Particle (SEP) events is that these (proton-dominated) fluxes are accelerated in heliospheric shock sources created by Interplanetary Coronal Mass Ejections (ICMEs), and then travel mainly along interplanetary magnetic field lines connecting the shock(s) to the observer(s). This places a particular emphasis on the role of the heliospheric conditions during the event, requiring a realistic description of the latter to interpret and/or model SEP events. The well-known ENLIL heliospheric simulation with cone model generated ICME shocks is used together with the SEPMOD particle event modeling scheme to demonstrate the value of applying these concepts at multiple inner heliosphere sites.
Ground-Based Observations of Powerful Solar Flares Precursors
Authors: Snegirev Sergei S. , Sheiner Olga A. , Smirnova Anna S. 
Published: July 2018

AbstractThe opportunity of development the short-term forecasting technique of geoeffective solar flares is presented in this study. This technique is based on the effect of growth the fluctuations of horizontal component of geomagnetic field before the solar proton flares, that is considered as a prognostic parameter of solar proton flares.
Regularities of the IMF Sector Structure in the Last 170 Years
Authors: Vokhmyanin Mikhail V. , Zolotova Nadezhda V. , Ponyavin Dmitry I. 
Published: July 2018

AbstractThe interplanetary magnetic field (IMF) controls magnetospheric currents which cause variations of the ground-based magnetic field. Regular magnetic observations made in the 19th century allow us to infer daily IMF polarities back to 1844. The results coincide with satellite data in about 79% days. Moreover, for the most part of the 19th and 20th centuries, proxies obtained from various geomagnetic data (Helsinki, Saint-Petersburg, Potsdam, and Ekaterinburg) show the same patterns. This suggests that the reliability of the proxies is sufficient to study the IMF in the past. The large-scale organization of the IMF polarities, the so-called sector structure, reveals semi-centennial north-south displacements of the heliospheric current sheet (HCS).
The Relationship between Long-Duration Gamma-Ray Flares and Solar Cosmic Rays
Authors: Hudson Hugh S. 
Published: July 2018

AbstractA characteristic pattern of solar hard X-ray emission, first identified in SOL1969-03-30 by Frost & Dennis (1971), turns out to have a close association with the prolonged high-energy gamma-ray emission originally observed by Forrestet al.(1985). This identification has become clear via the observations of long-duration γ-ray flares by theFermi/LAT experiment, for example in the event SOL2014-09-01. The distinctive features of these events include flat hard X-ray spectra extending well above 100 keV, a characteristic pattern of time development, low-frequency gyrosynchrotron peaks, CME association, and gamma-rays identifiable with pion decay originating in GeV ions. The identification of these events with otherwise known solar structures nevertheless remains elusive, in spite of the wealth of EUV imagery available from SDO/AIA. The quandary is that these events have a clear association with SEPs in the high corona, and yet the gamma-ray production implicates the photosphere itself, despite the strong mirror force that should focus the particlesawayfrom the Sun We discuss the morphology of these phenomena and propose a solution to this problem.
PFSS-Based Solar Wind Forecast and the Radius of the Source-Surface
Authors: Nikolić Ljubomir 
Published: July 2018

AbstractThe potential-field source-surface (PFSS) model of the solar corona is a widely used tool in the space weather research and operations. In particular, the PFSS model is used in solar wind forecast models which empirically associate solar wind properties with the numerically derived coronal magnetic field. In the PFSS model, the spherical surface where magnetic field lines are forced to open is typically placed at 2.5 solar radii. However, the results presented here suggest that setting this surface (the source-surface) to lower heights can provide a better agreement between observed and modelled coronal holes during the current solar cycle. Furthermore, the lower heights of the source-surface provide a better match between observed and forecasted solar wind speed.
Structure of the Power Spectral Density of Galactic Cosmic Ray Variation during 1953-2016
Authors: Väisänen Pauli , Usoskin Ilya , Mursula Kalevi 
Published: July 2018

AbstractFluxes of galactic cosmic rays (GCR) observed at 1 AU are modulated inside the heliosphere at different time scales. Here we study the properties of the power spectral density (PSD) of galactic cosmic ray variability using hourly data from 31 neutron monitors (NM) from 1953 to 2016. We pay particular attention to the reliability of the used datasets and methods. We present the overall PSD and discuss different parts of the spectrum and the related periodicities. We find significant spectral peaks at the periods of 11 years, 1.75 years, 155 days, 27 days and 24 hours and the harmonics of the latter two peaks. We calculate a power law slope of −1.79 ± 0.13 for the period range between 50 and 130 hours and a slope of −1.34 ± 0.17 for the period range between 40 days and 3.4 years (1000 − 30000 h).
Geomagnetopause Position and Shape Dependence on Solar Wind Plasma and IMF Parameters: Analytic Model Comparison with Observations and 3-D MHD Runs
Authors: Verigin M. I. , Kotova G. A. , Bezrukikh V. V. 
Published: July 2018

AbstractIt is generally accepted to use the solar wind ram pressure ρV2 and the IMF Bz component for empirical description of the geo-magnetopause position and shape. A specific feature of the present paper is not to use the solar wind ρV2 but the thermal Pth and magnetic field Pmag pressures adjacent to the magnetopause for proper modelling. These pressures are deduced from the results of 3-D MHD runs and analytic solutions for post bow shock MHD flow in Lagrangian variables. The magnetopause shape variation due to Bz component changes the so called ‘doubling factor’ fd, which can be analytically deduced from a Tsyganenko magnetospheric field ellipsoidal model. Including all the above effects in our analytical model leads to a good description of ‘rapid’ magnetopause approach to the Earth for southward IMF and to its ‘stagnant’ behaviour with the increase of northward IMF component.
Reinforcing a Double Dynamo Model with Solar-Terrestrial Activity in the Past Three Millennia
Authors: Zharkova V. V. , Shepherd S. J. , Popova E. , Zharkov S. I. 
Published: July 2018

AbstractBy applying Principal Components Analysis (PCA) to solar magnetic synoptic maps in cycle 21-23 obtained with Wilcox Solar Observatory we derived analytical expressions for two principal components and their summary curve of solar magnetic field oscillations defined by dipole magnetic sources. In this paper we extrapolate backwards three millennia the summary curve describing solar activity and compare it with the relevant historic data. The extrapolated summary curve shows a remarkable resemblance to the sunspot and terrestrial activity reported in the past millennia: the Maunder Minimum (1645-1715), Wolf minimum (1200), Oort minimum (1010-1050), Homer minimum (800-900 BC), the medieval warm period (900-1200), the Roman warm period (400-10BC). We note that Sporer minimum (1460-1550) derived from the increased abundance of isotope Δ14C is likely produced by a strong increase of galactic cosmic rays caused by a supernova Vela Junior occurred in the Southern hemisphere.
Excitation and Evolution of Transverse Loop Oscillations by Coronal Rain
Authors: Verwichte Erwin , Kohutova Petra , Antolin Patrick , Rowlands George , Neukirch Thomas 
Published: July 2018

AbstractWe present evidence of the excitation of vertically polarised transverse loop oscillations triggered by a catastrophic cooling of a coronal loop with two thirds of the loop mass comprising of cool rain mass. The nature and excitation of oscillations associated with coronal rain is not well understood. We consider observations of coronal rain using data from IRIS, SOT/Hinode and AIA/SDO in a bid to elucidate the excitation mechanism and evolution of wave characteristics. We apply an analytical model of wave-rain interaction, that predicts the inertial excitation amplitude of transverse loop oscillations as a function of the rain mass, to deduce the relative rain mass. It is consistent with the evolution of the oscillation period showing the loop losing a third of its mass due to falling coronal rain in a 10-15 minute time period.
A New Technique to Provide Realistic Input to CME Forecasting Models
Authors: Gopalswamy Nat , Akiyama Sachiko , Yashiro Seiji , Xie Hong 
Published: July 2018

AbstractWe report on a technique to construct a flux rope (FR) from eruption data at the Sun. The technique involves line-of-sight magnetic fields, post-eruption arcades in the corona, and white-light coronal mass ejections (CMEs) so that the FR geometric and magnetic properties can be fully defined in addition to the kinematic properties. We refer to this FR as FRED (Flux Rope from Eruption Data). We illustrate the FRED construction using the 2012 July 12 eruption and compare the coronal and interplanetary properties of the FR. The results indicate that the FRED input should help make realistic predictions of the components of the FR magnetic field in the heliosphere.
High Speed Solar Wind Forecast Model from the Solar Surface to 1AU Using Global 3D MHD Simulation
Authors: Den Mitsue , Tanaka Takashi , Kubo Yuki , Watari Shinichi 
Published: July 2018

AbstractEmanating from coronals holes (CHs), high speed streams (HSSs) cause recurrent geomagnetic disturbances in the Earth’s magnetosphere. For this reason being able to predict the occurrence and timing of the high speed solar wind is one of the more important issues in space weather forecasting. Currently, it is still difficult to estimate the effect of a CH in case that it extends from high latitudes to lower ones. To monitor the global solar wind condition we have therefore developed a three-dimensional MHD simulation code, the REProduce Plasma Universe (REPPU) code, that is driven by the solar magnetic field from the solar surface to 1AU. The connectivity of magnetic field lines from CHs to Earth’s orbit via HSSs has been investigated. Simulation results are presented and the usefulness of our model is discussed.
Data Handling and Assimilation for Solar Event Prediction
Authors: Martens Petrus C. , Angryk Rafal A. 
Published: July 2018

AbstractThe prediction of solar flares, eruptions, and high energy particle storms is of great societal importance. The data mining approach to forecasting has been shown to be very promising. Benchmark datasets are a key element in the further development of data-driven forecasting. With one or more benchmark data sets established, judicious use of both the data themselves and the selection of prediction algorithms is key to developing a high quality and robust method for the prediction of geo-effective solar activity. We review here briefly the process of generating benchmark datasets and developing prediction algorithms.
Four-Spacecraft Magnetic Curvature Analysis on Kelvin-Helmholtz Waves in MHD Simulations
Authors: Kieokaew R. , Foullon C. , Lavraud B. 
Published: July 2018

AbstractFour-spacecraft missions are probing the Earth’s magnetospheric environment with high potential for revealing spatial and temporal scales of a variety of in-situ phenomena. Magnetic curvature is intrinsic to curved magnetic fields where the magnetic energy is stored in the form of magnetic tension. In-situ magnetic curvature has been resolved by the four-spacecraft technique called “magnetic curvature analysis” (MCA). We test the MCA on 2.5D MHD simulations of curved magnetic structures induced by Kelvin-Helmholtz (KH) waves, with increasing (regular) tetrahedron sizes of virtual spacecraft. We have found variations of the curvature vectors both in radii and orientations depending on the sizes of the tetrahedron. This is helpful to better understand the MCA measures when the technique is applied to in-situ data without knowing the scale sizes of plasma structures under consideration. This study lends support for cross-scale observations to better understand the nature of curvature and its role in plasma phenomena.
Numerical Short-Term Solar Activity Forecasting
Authors: Wang Huaning , Yan Yihua , He Han , Huang Xin , Dai Xinghua , Zhu Xiaoshuai , Du Zhanle , Zhao Hui , Yan Yan 
Published: July 2018

AbstractIt is well known that the energy for solar eruptions comes from magnetic fields in solar active regions. Magnetic energy storage and dissipation are regarded as important physical processes in the solar corona. With incomplete theoretical modeling for eruptions in the solar atmosphere, activity forecasting is mainly supported with statistical models. Solar observations with high temporal and spatial resolution continuously from space well describe the evolution of activities in the solar atmosphere, and combined with three dimensional reconstruction of solar magnetic fields, makes numerical short-term (within hours to days) solar activity forecasting possible. In the current report, we propose the erupting frequency and main attack direction of solar eruptions as new forecasts and present the prospects for numerical short-term solar activity forecasting based on the magnetic topological framework in solar active regions.
Analysis of Magnetic Field Variations Produced by Equatorial Electro-Jets
Authors: López Ericson , Aldás Franklin , Yoshikawa Akimasa 
Published: July 2018

AbstractThe Equatorial Electrojet (EEJ) is a narrow band of electrons flowing from east to west at daytime at low latitudes. The electron current produces a magnetic field variation that can be measured at different latitudes. In this work, we have used the data analysis in order to quantify the solar and lunar contributions to those variations and study the morphology of the EEJ current.
The Advective‐Diffusive Morphodynamics of Mixed Bedrock‐Alluvial Rivers Subjected to Spatiotemporally Varying Sediment Supply
Authors: Zhang Li , Stark Colin , Schumer Rina , Kwang Jeffrey , Li Tiejian , Fu Xudong , Wang Guangqian , Parker Gary 
Published: July 2018

AbstractMountain rivers subject to earthquakes and intense precipitation have highly variable sediment supply rates. Here we consider the morphodynamics of 1‐D mixed bedrock‐alluvial rivers with temporally varying sediment supply rates. We use a periodic sedimentograph, characterized by short periods of high sediment feed rate and longer periods of low sediment feed rate. We study the problem with a corrected Macroroughness Saltation‐Abrasion‐Alluviation model. In this model, incision is driven by bedload colliding with bedrock, but incision can be turned off by either zero sediment transport or complete alluviation. The formulation is advective‐diffusive, the former capturing upstream‐migrating knickpoints and the latter capturing smearing of the sedimentograph downstream. The steady state balance between incision and uplift is characterized by a bedrock slope that varies downstream, exhibiting low values at the upstream end of the domain and higher values farther downstream. Sufficiently far downstream, the bedrock slope approaches that predicted for constant feed rates. The zone of low slope near the feed point corresponds to a pocket (zone of locally depressed bedrock slope) in the longitudinal profile, which is repeatedly drowned in and flushed of sediment. The steady state slope profile of a shorter reach is a truncated version of that of a longer reach. A limiting reach length including the pocket defines a sedimentograph boundary layer, where the effects of sediment feed fluctuation are felt.
Toward a Robust Elastic Geobarometry of Kyanite Inclusions in Eclogitic Diamonds
Authors: Nestola F. , Prencipe M. , Nimis P. , Sgreva N. , Perritt S. H. , Chinn I. L. , Zaffiro G. 
Published: July 2018

AbstractHere we report the first results from elastic geobarometry applied to a kyanite inclusion entrapped within an eclogitic diamond (from Voorspoed mine, South Africa) using micro‐Raman and Fourier transform infrared spectroscopy, electron microprobe analysis, ab initio calculations, and finite element modeling. Application of elastic geobarometry to very elastically anisotropic kyanite inclusions is challenging, as current models do not allow for elastic anisotropy. In order to minimize the effects of anisotropy, we have explored the effects of deviatoric stress on Raman modes via ab initio density functional theory. The results allowed us to select the Raman mode (at ca. 638 cm−1) that is the least sensitive to deviatoric stress. The shift of this band in the inclusion while still trapped within the diamond relative to the inclusion in air (once liberated) was used under hydrostatic approximation to determine a residual pressure on the inclusion of 0.184 ± 0.045 GPa and an entrapment pressure of 5.2 ± 0.3 GPa (~160 km depth) for an FTIR N‐aggregation residence temperature of 1119 ± 50 °C. This is the first geothermobarometric determination for a diamond from the Voorspoed kimberlite. It overlaps with P–T estimates obtained by traditional chemical geobarometry for diamonds from other kimberlites from the Kaapvaal craton, suggesting that the hydrostatic approximation does not introduce significant errors in the geobarometric evaluation. Our protocol of Raman peak selection can be used for geobarometry of further kyanite‐bearing diamonds and may provide a guide for more robust geobarometry of other types of mineral inclusions in diamonds, both eclogitic and peridotitic.
Microbiome functioning depends on individual and interactive effects of the environment and community structure
Authors: Orland Chloé , Emilson Erik J S , Basiliko Nathan , Mykytczuk Nadia C S , Gunn John M , Tanentzap Andrew J 
Published: July 2018

Abstract
How ecosystem functioning changes with microbial communities remains an open question in natural ecosystems. Both present-day environmental conditions and historical events, such as past differences in dispersal, can have a greater influence over ecosystem function than the diversity or abundance of both taxa and genes. Here, we estimated how individual and interactive effects of microbial community structure defined by diversity and abundance, present-day environmental conditions, and an indicator of historical legacies influenced ecosystem functioning in lake sediments. We studied sediments because they have strong gradients in all three of these ecosystem properties and deliver important functions worldwide. By characterizing bacterial community composition and functional traits at eight sites fed by discrete and contrasting catchments, we found that taxonomic diversity and the normalized abundance of oxidase-encoding genes explained as much variation in CO2 production as present-day gradients of pH and organic matter quantity and quality. Functional gene diversity was not linked to CO2 production rates. Surprisingly, the effects of taxonomic diversity and normalized oxidase abundance in the model predicting CO2 production were attributable to site-level differences in bacterial communities unrelated to the present-day environment, suggesting that colonization history rather than habitat-based filtering indirectly influenced ecosystem functioning. Our findings add to limited evidence that biodiversity and gene abundance explain patterns of microbiome functioning in nature. Yet we highlight among the first time how these relationships depend directly on present-day environmental conditions and indirectly on historical legacies, and so need to be contextualized with these other ecosystem properties.