bluuebunny/crossref_metadata_2025_split huggingface dataset:
SC‐Associated Electric Field Variations in the Magnetosphere and Ionospheric Convective Flows
Authors: Kim S.‐I. , Kim K.‐H. , Kwon H.‐J. , Jin H. , Lee E. , Jee G. , Nishitani N. , Hori T. , Lester M. , Wygant J. R. 
Published: October 2017

AbstractWe examine magnetic and electric field perturbations associated with a sudden commencement (SC), caused by an interplanetary (IP) shock passing over the Earth's magnetosphere on 16 February 2013. The SC was identified in the magnetic and electric field data measured at Time History of Events and Macroscale Interactions during Substorms (THEMIS‐E; THE‐E: magnetic local time (MLT) = 12.4, L = 6.3), Van Allen Probe‐A (VAP‐A: MLT = 3.2, L = 5.1), and Van Allen Probe‐B (VAP‐B: MLT = 0.2. L = 4.9) in the magnetosphere. During the SC interval, THE‐E observed a dawnward‐then‐duskward electric (E) field perturbation around noon, while VAP‐B observed a duskward E field perturbation around midnight. VAP‐A observed a dawnward‐then‐duskward E field perturbation in the postmidnight sector, but the duration and magnitude of the dawnward E perturbation are much shorter and weaker than that at THE‐E. That is, the E field signature changes with local time during the SC interval. The Super Dual Auroral Radar Network radar data indicate that the ionospheric plasma motions during the SC are mainly due to the E field variations observed in space. This indicates that the SC‐associated E field in space plays a significant role in determining the dynamic variations of the ionospheric convection flow. By comparing previous SC MHD simulations and our observations, we suggest that the E field variations observed at the spacecraft are produced by magnetospheric convection flows due to deformation of the magnetosphere as the IP shock sweeps the magnetopause.
Application of Manley‐Rowe Relation in Analyzing Nonlinear Interactions Between Planetary Waves and the Solar Semidiurnal Tide During 2009 Sudden Stratospheric Warming Event
Authors: He Maosheng , Chau Jorge Luis , Stober Gunter , Hall Chris M. , Tsutsumi Masaki , Hoffmann Peter 
Published: October 2017

AbstractUpper mesospheric winds observed by the Svalbard specular meteor radar (16.01°E,78.16°N) are analyzed to study the tidal variabilities during the 2009 sudden stratospheric warming (SSW). We report a textbook case of nonlinear interactions between planetary waves (PWs) and the SW2 tide (SWm denotes semidiurnal westward propagating tidal mode with zonal wave number m). The Lomb‐Scargle algorithm, bispectrum, wavelet spectra, and Manley‐Rowe relations are combined to explore the frequency match, phase coherence, energy budget, and wave number relations among the interacting waves and their temporal evolution. Our results suggest that (1) 5, 10, 16 day PW normal modes interact with SW2 generating significant sidebands (S2Ss) at frequencies lower and higher than SW2, known as SW1 and SW3 enhancements, respectively; (2) SW2 is the main energy supplier for both SW1 and SW3, hence shrinks in the interactions; (3) whereas the PWs export relatively negligible energy to SW3 but accept energy from SW2 in generating SW1, therefore, the PWs is not subject to the interactions but controlled by external dynamics, which might in turn act as a key in switching on/off the SW1 and SW3 interactions independently; (4) the SW1 enhancement could be explained as a byproduct of the planetary wave amplification by stimulated tidal decay (PASTIDE); (5) PASTIDE contributes energy to the secondary PW in the late SSW stage reported in previous studies; and (6) one SW1 component associated with the 16 day PW is very close to the semidiurnal lunar mode in frequency, which might contaminate the estimation of the lunar tidal amplification in previous studies.
Surface Current Patterns in the Northeastern Chukchi Sea and Their Response to Wind Forcing
Authors: Fang Ying‐Chih , Potter Rachel A. , Statscewich Hank , Weingartner Thomas J. , Winsor Peter , Irving Brita K. 
Published: October 2017

AbstractWe measured northeastern Chukchi Sea surface currents using high‐frequency radar systems (HFR) during the ice‐free periods of August to October from 2010–2014. We analyzed these data, along with regional winds, using Self‐Organizing Maps (SOM) to develop a set of surface current‐wind patterns. Temporal changes in the SOM patterns consist predominantly of two patterns comprising northeastward and southwestward surface currents. A third pattern represents a transitional stage established during the onset of strong northeasterly winds. These patterns are analogous to the first two eigenmodes of an empirical orthogonal function analysis of the HFR data. The first principal component (PC1) is significantly correlated (∼0.8) to that of the winds and is directly related to the time series of SOM‐derived patterns. The sign of PC1 changes when the speed of local northeasterly winds exceeds ∼6 m s−1, at which point the northeastward surface currents reverse to the southwest. This finding agrees with previous models and observations that suggest this wind threshold is needed to overcome the pressure gradient between the Pacific and Arctic Oceans. The transitional stage is characterized by alongshore currents bifurcating in the vicinity of Icy Cape and wind‐driven Ekman currents north of 71.5°N. Its development is a manifestation of interactions among the poleward pressure gradient, wind stress, and geostrophic flow due to the coastal setdown.
Spatial Variability of Wet Troposphere Delays Over Inland Water Bodies
Authors: Mehran Ali , Clark Elizabeth A. , Lettenmaier Dennis P. 
Published: October 2017

AbstractSatellite radar altimetry has enabled the study of water levels in large lakes and reservoirs at a global scale. The upcoming Surface Water and Ocean Topography (SWOT) satellite mission (scheduled launch 2020) will simultaneously measure water surface extent and elevation at an unprecedented accuracy and resolution. However, SWOT retrieval accuracy will be affected by a number of factors, including wet tropospheric delay—the delay in the signal's passage through the atmosphere due to atmospheric water content. In past applications, the wet tropospheric delay over large inland water bodies has been corrected using atmospheric moisture profiles based on atmospheric reanalysis data at relatively coarse (tens to hundreds of kilometers) spatial resolution. These products cannot resolve subgrid variations in wet tropospheric delays at the spatial resolutions (of 1 km and finer) that SWOT is intended to resolve. We calculate zenith wet tropospheric delays (ZWDs) and their spatial variability from Weather Research and Forecasting (WRF) numerical weather prediction model simulations at 2.33 km spatial resolution over the southwestern U.S., with attention in particular to Sam Rayburn, Ray Hubbard, and Elephant Butte Reservoirs which have width and length dimensions that are of order or larger than the WRF spatial resolution. We find that spatiotemporal variability of ZWD over the inland reservoirs depends on climatic conditions at the reservoir location, as well as distance from ocean, elevation, and surface area of the reservoir, but that the magnitude of subgrid variability (relative to analysis and reanalysis products) is generally less than 10 mm.
Deriving Global OH Abundance and Atmospheric Lifetimes for Long‐Lived Gases: A Search for CH3CCl3 Alternatives
Authors: Liang Qing , Chipperfield Martyn P. , Fleming Eric L. , Abraham N. Luke , Braesicke Peter , Burkholder James B. , Daniel John S. , Dhomse Sandip , Fraser Paul J. , Hardiman Steven C. , Jackman Charles H. , Kinnison Douglas E. , Krummel Paul B. , Montzka Stephen A. , Morgenstern Olaf , McCulloch Archie , Mühle Jens , Newman Paul A. , Orkin Vladimir L. , Pitari Giovanni , Prinn Ronald G. , Rigby Matthew , Rozanov Eugene , Stenke Andrea , Tummon Fiona , Velders Guus J. M. , Visioni Daniele , Weiss Ray F. 
Published: October 2017

AbstractAn accurate estimate of global hydroxyl radical (OH) abundance is important for projections of air quality, climate, and stratospheric ozone recovery. As the atmospheric mixing ratios of methyl chloroform (CH3CCl3) (MCF), the commonly used OH reference gas, approaches zero, it is important to find alternative approaches to infer atmospheric OH abundance and variability. The lack of global bottom‐up emission inventories is the primary obstacle in choosing a MCF alternative. We illustrate that global emissions of long‐lived trace gases can be inferred from their observed mixing ratio differences between the Northern Hemisphere (NH) and Southern Hemisphere (SH), given realistic estimates of their NH‐SH exchange time, the emission partitioning between the two hemispheres, and the NH versus SH OH abundance ratio. Using the observed long‐term trend and emissions derived from the measured hemispheric gradient, the combination of HFC‐32 (CH2F2), HFC‐134a (CH2FCF3, HFC‐152a (CH3CHF2), and HCFC‐22 (CHClF2), instead of a single gas, will be useful as a MCF alternative to infer global and hemispheric OH abundance and trace gas lifetimes. The primary assumption on which this multispecies approach relies is that the OH lifetimes can be estimated by scaling the thermal reaction rates of a reference gas at 272 K on global and hemispheric scales. Thus, the derived hemispheric and global OH estimates are forced to reconcile the observed trends and gradient for all four compounds simultaneously. However, currently, observations of these gases from the surface networks do not provide more accurate OH abundance estimate than that from MCF.
Raindrop Size Distribution Measurements at 4,500 m on the Tibetan Plateau During TIPEX‐III
Authors: Chen Baojun , Hu Zhiqun , Liu Liping , Zhang Guifu 
Published: October 2017

AbstractAs part of the third Tibetan Plateau Atmospheric Scientific Experiment field campaign, raindrop size distribution (DSD) measurements were taken with a laser optical disdrometer in Naqu, China, at 4,508 m above sea level (asl) during the summer months of 2013, 2014, and 2015. The characteristics of DSDs for five different rain rates, for two rain types (convective and stratiform), and for daytime and nighttime rains were studied. The shapes of the averaged DSDs were similar for different rain rates, and the width increased with rainfall intensity. Little difference was found in stratiform DSDs between day and night, whereas convective DSDs exhibited a significant day‐night difference. Daytime convective DSDs had larger mass‐weighted mean diameters (Dm) and smaller generalized intercepts (NW) than the nighttime DSDs. The constrained relations between the intercept N0 and shape μ, slope Λ and μ, and NW and Dm of gamma DSDs were derived. We also derived empirical relations between Dm and the radar reflectivity factor in the Ku and Ka bands.
Rapid Adjustments Cause Weak Surface Temperature Response to Increased Black Carbon Concentrations
Authors: Stjern Camilla Weum , Samset Bjørn Hallvard , Myhre Gunnar , Forster Piers M. , Hodnebrog Øivind , Andrews Timothy , Boucher Olivier , Faluvegi Gregory , Iversen Trond , Kasoar Matthew , Kharin Viatcheslav , Kirkevåg Alf , Lamarque Jean‐François , Olivié Dirk , Richardson Thomas , Shawki Dilshad , Shindell Drew , Smith Christopher J. , Takemura Toshihiko , Voulgarakis Apostolos 
Published: October 2017

AbstractWe investigate the climate response to increased concentrations of black carbon (BC), as part of the Precipitation Driver Response Model Intercomparison Project (PDRMIP). A tenfold increase in BC is simulated by nine global coupled‐climate models, producing a model median effective radiative forcing of 0.82 (ranging from 0.41 to 2.91) W m−2, and a warming of 0.67 (0.16 to 1.66) K globally and 1.24 (0.26 to 4.31) K in the Arctic. A strong positive instantaneous radiative forcing (median of 2.10 W m−2 based on five of the models) is countered by negative rapid adjustments (−0.64 W m−2 for the same five models), which dampen the total surface temperature signal. Unlike other drivers of climate change, the response of temperature and cloud profiles to the BC forcing is dominated by rapid adjustments. Low‐level cloud amounts increase for all models, while higher‐level clouds are diminished. The rapid temperature response is particularly strong above 400 hPa, where increased atmospheric stabilization and reduced cloud cover contrast the response pattern of the other drivers. In conclusion, we find that this substantial increase in BC concentrations does have considerable impacts on important aspects of the climate system. However, some of these effects tend to offset one another, leaving a relatively small median global warming of 0.47 K per W m−2—about 20% lower than the response to a doubling of CO2. Translating the tenfold increase in BC to the present‐day impact of anthropogenic BC (given the emissions used in this work) would leave a warming of merely 0.07 K.
Can We Monitor Snow Properties on Sea Ice to Investigate Its Role in Tropospheric Ozone Depletion?
Authors: Domine Florent 
Published: October 2017

AbstractIn the lower troposphere over the Arctic Ocean, ozone is often destroyed in spring by chemical chain reactions involving the reactive bromine species Br and BrO. The role of surface snow in generating reactive bromine has been suspected, but many details of the processes not understood. Using unique data such as BrO concentrations from instruments on buoys, Burd et al. (2017, https://doi.org/10.1002/2017JD026906) observed that the snowmelt onset date often coincides with the end of the reactive bromine season. They proposed that the decrease in snow‐specific surface area and/or the occurrence of liquid water in snow induced by melting dramatically slows the rate of surface reactions generating bromine, indicating that the physical state of the snow is critical for bromine generation. Their suggestion is discussed, and a method to test it using novel instrumentation recently available is proposed.
The Total Electron Content of the Martian Ionosphere From MRO/SHARAD Observations
Authors: Mendillo Michael , Narvaez Clara , Campbell Bruce 
Published: October 2017

AbstractThe Shallow Radar (SHARAD) on the Mars Reconnaissance Orbiter (MRO), used to search for subsurface water ice, requires corrections to range delays and image distortions caused by radiowave propagation through the Martian ionosphere. These corrections yield a phase parameter that is linearly correlated with values of the total electron content (TEC), defined as the integral of the electron density profile Ne(h). This new database has been validated using previous observational patterns of TEC magnitudes and variability versus latitude, local time, and season. The SHARAD TEC data span the years 2007 to 2014, providing the first opportunity to study solar cycle effects upon daytime TEC magnitudes. A parameterization of TEC versus solar zenith angle and solar flux, within the context of photochemical equilibrium theory, provides a flexible TEC module for the Mars Initial Reference Ionosphere (MIRI) model. A high spatial resolution study of TEC variability in the southern hemisphere confirmed a previously tentative conclusion about daytime TEC morphology controlled by the local inclination angles of crustal magnetic fields.
Silicate Weathering and Carbon Cycle Controls on the Oligocene‐Miocene Transition Glaciation
Authors: Stewart Joseph A. , James Rachael H. , Anand Pallavi , Wilson Paul A. 
Published: October 2017

AbstractChanges in both silicate weathering rates and organic carbon burial have been proposed as drivers of the transient “Mi‐1” glaciation event at the Oligocene‐Miocene transition (OMT; ~23 Ma). However, detailed geochemical proxy data are required to test these hypotheses. Here we present records of Li/Ca, Mg/Ca, Cd/Ca, U/Ca, δ18O, δ13C, and shell weight in planktonic foraminifera from marine sediments spanning the OMT in the equatorial Atlantic Ocean. Li/Ca values increase by 1 μmol/mol across this interval. We interpret this to indicate an ~20% increase in silicate weathering rates, which would have lowered atmospheric CO2, potentially forcing the Antarctic glaciation ~ 23 Ma. δ13C of thermocline dwelling planktonic foraminifera track the global increase in seawater δ13C across the OMT and during the Mi‐1 event, hence supporting a hypothesized global increase in organic carbon burial rates. High δ13C previously measured in epipelagic planktonic foraminifera and high Cd/Ca ratios during Mi‐1 are interpreted to represent locally enhanced primary productivity, stimulated by increased nutrients supply to surface waters. The fingerprint of high export production and associated organic carbon burial at this site is found in reduced bottom water oxygenation (inferred from high foraminiferal U/Ca) and enhanced respiratory dissolution of carbonates, characterized by reduced foraminiferal shell weight. Replication of our results elsewhere would strengthen the case that weathering‐induced CO2 sequestration preconditioned climate for Antarctic ice sheet growth across the OMT, and increased burial of organic carbon acted as a feedback that intensified cooling at this time.
Possible Cause of Extremely Bright Aurora Witnessed in East Asia on 17 September 1770
Authors: Ebihara Yusuke , Hayakawa Hisashi , Iwahashi Kiyomi , Tamazawa Harufumi , Kawamura Akito Davis , Isobe Hiroaki 
Published: October 2017

AbstractExtremely bright aurora was witnessed in East Asia on 17 September 1770, according to historical documents. The aurora was described as “as bright as a night with full moon” at magnetic latitude of 25°. The aurora was dominated by red color extending from near the horizon up beyond the polar star (corresponding to elevation angle of ~35°). We performed a two‐stream electron transport code to calculate the volume emission rates at 557.7 nm (OI) and 630.0 nm (OI). Two types of distribution of precipitating electrons were assumed. The first one is based on the unusually intense electron flux measured by the DMSP satellite in the March 1989 storm. The distribution consists of hot (peaking at 3 keV) and cold (peaking at 71 eV) components. The second one is the same as the first one, but the hot component is removed. We call this high‐intensity low‐energy electrons (HILEEs). The first spectrum results in an auroral display with a bright, lower green border. The second one results in red‐dominated aurora extending up to the elevation angle of 35° when the equatorward boundary of the electron precipitation is located at 32° invariant latitude. The poleward boundary of the precipitation would be 42° invariant latitude or greater to explain the auroral display extending from near the horizon. The origin of the HILEEs is probably the plasma sheet or the plasmasphere that is transported earthward toL ~ 1.39 due to enhanced magnetospheric convection. Local heating or acceleration is also plausible.
Social Desirability and the Interpretation of Uncertainty Terms in Self‐Report Questions
Authors: Holtgraves Thomas 
Published: October 2017

SummaryUncertainty terms (e.g., possible) are words that are not fixed and hence open to interpretation. This research examined the role of social desirability in how these words are interpreted in self‐report questions. Participants in Experiments 1 (N = 96; MTurk workers) and 2 (N = 96; college students) judged trait (N = 48) and behavior (N = 36) items endorsed by a hypothetical individual to be more likely if they were lower in social desirability. In Experiments 3 (N = 97) and 4 (N = 97) college student participants interpreted four different uncertainty terms (likely, possible, unlikely, and pretty sure) as indicating greater certainty when they referred to socially undesirable (relative to socially desirable) traits (N = 36) and behaviors (N = 24). These results suggest that participants may interpret self‐report items differently, depending on the social desirability of the content.Copyright © 2017 John Wiley & Sons, Ltd.
A fuzzy C‐regression model algorithm using a new PSO algorithm
Authors: Taieb Adel , Soltani Moez , Chaari Abdelkader 
Published: October 2017

SummaryIn this paper, a new methodology is introduced for the identification of the parameters of the multiple‐input–multiple‐output local linear Takagi‐Sugeno fuzzy models using the weighted recursive least squares (WRLS). The WRLS is sensitive to initialization, which leads to no convergence. In order to overcome this problem, adaptive chaos particle swarm optimization is proposed to optimize the initial states of WRLS. This new algorithm is improved versions of the original particle swarm optimization algorithm. Finally, comparative experiments are designed to verify the validity of the proposed clustering algorithm and the Takagi‐Sugeno fuzzy model identification method, and the results show that the new method is effective in describing a complicated nonlinear system with significantly high accuracies compared with approaches in the literature.
Spectroscopic Indications of Tunnel Barrier Charging as the Switching Mechanism in Memristive Devices
Authors: Arndt Benedikt , Borgatti Francesco , Offi Francesco , Phillips Monifa , Parreira Pedro , Meiners Thorsten , Menzel Stephan , Skaja Katharina , Panaccione Giancarlo , MacLaren Donald A. , Waser Rainer , Dittmann Regina 
Published: October 2017

AbstractResistive random access memory is a promising, energy‐efficient, low‐power “storage class memory” technology that has the potential to replace both flash storage and on‐chip dynamic memory. While the most widely employed systems exhibit filamentary resistive switching, interface‐type switching systems based on a tunable tunnel barrier are of increasing interest. They suffer less from the variability induced by the stochastic filament formation process and the choice of the tunnel barrier thickness offers the possibility to adapt the memory device current to the given circuit requirements. Heterostructures consisting of a yttria‐stabilized zirconia (YSZ) tunnel barrier and a praseodymium calcium manganite (PCMO) layer are employed. Instead of spatially localized filaments, the resistive switching process occurs underneath the whole electrode. By employing a combination of electrical measurements, in operando hard X‐ray photoelectron spectroscopy and electron energy loss spectroscopy, it is revealed that an exchange of oxygen ions between PCMO and YSZ causes an electrostatic modulation of the effective height of the YSZ tunnel barrier and is thereby the underlying mechanism for resistive switching in these devices.
Thrombosis‐Responsive Thrombolytic Coating Based on Thrombin‐Degradable Tissue Plasminogen Activator (t‐PA) Nanocapsules
Authors: Li Cong , Du Hui , Yang Aizhen , Jiang Shuaibing , Li Zhenhua , Li Dan , Brash John L. , Chen Hong 
Published: October 2017

AbstractSurface modification with bioactive agents capable of combating thrombosis is a widely used strategy for developing antithrombotic biomaterials. However, exposure of the blood to the antithrombotic agent on the material surface may cause hemostatic disorders under normal conditions. Ideally an implanted biomaterial should respond appropriately on demand to a specific change in the physiologic environment, as happens in the body itself. In the present study, a thrombosis‐responsive surface coating with the ability to lyse fibrin as it forms is reported. The coating consists of nanocapsules (NCs) in which the fibrinolysis activator t‐PA is encapsulated in a thrombin‐degradable hydrogel shell. The t‐PA NCs are attached to several materials covalently through a polydopamine adhesive layer. The resulting surfaces are treated with the antifouling agent glutathione (GSH) to prevent further interactions with blood/plasma components. The t‐PA NCs/GSH‐coated surface is stable and remain inert in normal plasma environment while releasing t‐PA and promoting fibrinolysis when thrombin is present. The fibrinolytic activity increases with increasing thrombin concentration, and therefore presumably with the extent of thrombosis. This work constitutes the first report of an antithrombotic coating whose function is triggered and regulated, respectively, by the appearance of thrombin and the extent of coagulation.