bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and characterization of an ice-selecting pumped counterflow
virtual impactor (IS-PCVI) to study ice crystal residuals
Authors: Hiranuma Naruki , Möhler Ottmar , Kulkarni Gourihar , Schnaiter Martin , Vogt Steffen , Vochezer Paul , Järvinen Emma , Wagner Robert , Bell David M. , Wilson Jacqueline , Zelenyuk Alla , Cziczo Daniel J. 
Published: August 2016

Abstract. Separation of particles that play a role in cloud activation and ice nucleation from interstitial aerosols has become necessary to further understand aerosol-cloud interactions. The pumped counterflow virtual impactor (PCVI), which uses a vacuum pump to accelerate the particles and increase their momentum, provides an accessible option for dynamic and inertial separation of cloud elements. However, the use of a traditional PCVI to extract large cloud hydrometeors is difficult mainly due to its small cut-size diameters (< 5 µm). Here, for the first time we describe a development of an ice-selecting PCVI (IS-PCVI) to separate ice in controlled mixed-phase cloud system based on the particle inertia with the cut-off diameter  ≥  10 µm. We also present its laboratory application demonstrating the use of the impactor under a wide range of temperature and humidity conditions. The computational fluid dynamics simulations were initially carried out to guide the design of the IS-PCVI. After fabrication, a series of validation laboratory experiments were performed coupled with the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) expansion cloud simulation chamber. In the AIDA chamber, test aerosol particles were exposed to the ice supersaturation conditions (i.e., RHice > 100 %), where a mixture of droplets and ice crystals was formed during the expansion experiment. In parallel, the flow conditions of the IS-PCVI were actively controlled, such that it separated ice crystals from a mixture of ice crystals and cloud droplets, which were of diameter  ≥  10 µm. These large ice crystals were passed through the heated evaporation section to remove the water content. Afterwards, the residuals were characterized with a suite of online and offline instruments downstream of the IS-PCVI. These results were used to assess the optimized operating parameters of the device in terms of (1) the critical cut-size diameter, (2) the transmission efficiency and (3) the counterflow-to-input flow ratio. Particle losses were characterized by comparing the residual number concentration to the rejected interstitial particle number concentration. Overall results suggest that the IS-PCVI enables inertial separation of particles with a volume-equivalent particle size in the range of  ~ 10–30 µm in diameter with small inadvertent intrusion (~  5 %) of unwanted particles.
Close-range radar rainfall estimation and error analysis
Authors: van de Beek C. Z. , Leijnse H. , Hazenberg P. , Uijlenhoet R. 
Published: August 2016

Abstract. Quantitative precipitation estimation (QPE) using ground-based weather radar is affected by many sources of error. The most important of these are (1) radar calibration, (2) ground clutter, (3) wet-radome attenuation, (4) rain-induced attenuation, (5) vertical variability in rain drop size distribution (DSD), (6) non-uniform beam filling and (7) variations in DSD. This study presents an attempt to separate and quantify these sources of error in flat terrain very close to the radar (1–2 km), where (4), (5) and (6) only play a minor role. Other important errors exist, like beam blockage, WLAN interferences and hail contamination and are briefly mentioned, but not considered in the analysis. A 3-day rainfall event (25–27 August 2010) that produced more than 50 mm of precipitation in De Bilt, the Netherlands, is analyzed using radar, rain gauge and disdrometer data. Without any correction, it is found that the radar severely underestimates the total rain amount (by more than 50 %). The calibration of the radar receiver is operationally monitored by analyzing the received power from the sun. This turns out to cause a 1 dB underestimation. The operational clutter filter applied by KNMI is found to incorrectly identify precipitation as clutter, especially at near-zero Doppler velocities. An alternative simple clutter removal scheme using a clear sky clutter map improves the rainfall estimation slightly. To investigate the effect of wet-radome attenuation, stable returns from buildings close to the radar are analyzed. It is shown that this may have caused an underestimation of up to 4 dB. Finally, a disdrometer is used to derive event and intra-event specific Z–R relations due to variations in the observed DSDs. Such variations may result in errors when applying the operational Marshall–Palmer Z–R relation. Correcting for all of these effects has a large positive impact on the radar-derived precipitation estimates and yields a good match between radar QPE and gauge measurements, with a difference of 5–8 %. This shows the potential of radar as a tool for rainfall estimation, especially at close ranges, but also underlines the importance of applying radar correction methods as individual errors can have a large detrimental impact on the QPE performance of the radar.
Desenvolvimento de habilidades de lógica em estu-dantes do ensino médio: Uma proposta fundamentada na neurociência
Authors: Bastos Narúsci Santos , Adamatti Diana Francisca , De Carvalho Fernanda Antoniolo 
Published: August 2016

Este trabalho propõem um estudo sobre o desenvolvimento de habilidades de lógica em estudantes do ensino médio, fundamentado na Neurociência. O objetivo é identificar possíveis mudanças na fisiologia cerebral pré e pós treinamento de lógica computacional e caracterizar as atividades cerebrais durante a resolução dos problemas do teste de lógica. Para realizar este estudo, foi necessário a coleta de sinais cerebrais em dois momentos: antes do treinamento de lógica computacional e após o treinamento. As coletas foram realizadas enquanto os indivíduos resolviam um teste de lógica. A partir desses dados analisam-se as áreas com maior atividade cerebral durante a resolução de cada questão proposta, que foram coletados através de técnica não-invasiva utilizando um equipamento EEG (Eletroencefalograma), que se baseia em registros de atividades elétricas cerebrais medidas através da superfície do escalpo. Estas técnicas de eletroencefalografia tem sido as mais utilizadas para a aquisição de sinais BCI ( Brain Computer Interface). Os sistemas BCI permitem a comunicação entre um indivíduo e determinados dispositivos externos, baseados em atividade neural gerada pelo cérebro sem exigir qualquer outro tipo de estímulo, como movimentos musculares. Para a análise das regiões cerebrais mais ativadas, foi realizado um estudo baseado na Neurociência, que é um conjunto de disciplinas que estudam o sistema nervoso, sua estrutura, desenvolvimento, funcionamento e, evolução e também suas alterações. Os resultados obtidos neste trabalho são promissores, mesmo que ainda iniciais, visto que podem contribuir para um melhor entendimento sobre as áreas cerebrais que sofrem mudanças pós treinamento em lógica computacional.
Banco de sementes do solo de uma Floresta Estacional Semidecidual, em Viçosa, Minas Gerais.
Authors: Neto Juvenal Pinheiro Batista , Reis Maria das Graças Ferreira , Reis Geraldo Gonçalves dos , Silva Alexandre Francisco da , Cacau Filipe Valadão 
Published: August 2016

Avaliou-se quantitativa e qualitativamente a florística do banco de sementes do solo de um fragmento de Floresta Estacional Semidecidual Montana, no município de Viçosa, MG. No final da estação chuvosa (março/2004), foram coletadas duas amostras de solo de 20 x 15 cm, com 5 cm de profundidade, no centro de seis subparcelas contíguas de 10 x 20 m, em dez parcelas permanentes de 20 x 60 m, em dez locais, totalizando 120 amostras (3,6 m2). As amostras de solo foram colocadas em estruturas de sombreamento de 11,5 % e 60 %, e as sementes germinadas foram identificadas em graminóides, herbáceo-cipós, arbustivas e arbóreas. Foram registradas 3.416 sementes germinadas, sendo 30,2 % graminóides, 29,2 % herbáceo-cipós, 17,5 % arbustivas e 23,1 % arbóreas, estas duas últimas distribuídas em 17 famílias, 25 gêneros e 31 espécies. Melastomataceae, Cecropiaceae e Piperaceae contribuíram com 31,8 %, 10,0 % e 8,8 % do total de espécies, respectivamente, sendo que Miconia cinnamomifolia e Leandra purpurascens foram responsáveis por 59,3 % das sementes arbustivo-arbóreas germinadas. As pioneiras se destacaram com 61,3 % das espécies e 88,5 % das sementes germinadas. Não foram registradas espécies secundárias tardias. A densidade média de sementes germinadas para todos os hábitos e locais foi de 949 sementes/m2. O número de espécies e de sementes germinadas do grupo arbustivo-arbóreo diferiu significativamente pelo teste Kruskal-Wallis (P ≤ 0,05) entre os locais estudados. Esses resultados indicam que, no banco de sementes do solo, há predomínio de espécies pioneiras que são importantes para a sucessão em clareiras ou após o corte da floresta. Porém, esse estoque de sementes não é suficiente para a continuidade do processo de sucessão, que inclui o estabelecimento de maior proporção de espécies secundárias iniciais e tardias. Isso indica que há necessidade de um manejo adequado do banco de plântulas para assegurar a continuidade da regeneração natural em florestas secundárias.
Optical–digital hybrid image search system in cloud environment
Authors: Ikeda Kanami , Kodate Kashiko , Watanabe Eriko 
Published: August 2016

Abstract
To improve the versatility and usability of optical correlators, we developed an optical–digital hybrid image search system consisting of digital servers and an optical correlator that can be used to perform image searches in the cloud environment via a web browser. This hybrid system employs a simple method to obtain correlation signals and has a distributed network design. The correlation signals are acquired by using an encoder timing signal generated by a rotating disk, and the distributed network design facilitates the replacement and combination of the digital correlation server and the optical correlator.
Ionospheric Characteristics and Models
Authors: Goodman John M. 
Published: August 2016

The ionized region roughly between 60 and 1200 km above the earth's surface is generally referred to as the ionosphere, even though some ionization persists above and below these bounds. Since most practical problems relate to the free electron number densityNe, it is convenient to specify a restricted altitude regime since many legacy systems such as LEO satellite and HF communications, HFDF (i.e., direction finding), and surveillance systems such as OTHR (over‐the‐horizon radar) depend upon this restricted region in a substantive way. But there are other applications to be considered. For example, exoionospheric electrons will augment the ionospheric total electron content (TEC) encountered by GNSS signal waveforms and will introduce additional group path delay errors if compensation schema are not introduced. As a result, many ionospheric models include the plasmaspheric contribution to the TEC.This article examines basic theory of the ionosphere, but much of the material details ionospheric structure, ranging from kilometer‐scale variations causing scintillation or spread‐F to the mesoscale features associated with electrodynamic forces, an imbedded geomagnetic field and upper atmospheric wind patterns. We look at these structures in both space and time for pertinent geographic regions, and identify relationships with solar–terrestrial physics, or space weather phenomena in the more modern vernacular. We examine traveling ionospheric disturbances (TID), an ionospheric tracer of atmospheric gravity waves (AGW), their properties, and their possible sources. Fundamental properties of the more relevant ionospheric models are identified and details are referenced. We cover real‐time forecasting and novel data assimilation schemes. We conclude with a section on challenges facing the ionospheric specialist.
Small global effect on terrestrial net primary production due to increased fossil fuel aerosol emissions from East Asia since the turn of the century
Authors: O'Sullivan M. , Rap A. , Reddington C. L. , Spracklen D. V. , Gloor M. , Buermann W. 
Published: August 2016

AbstractThe global terrestrial carbon sink has increased since the start of this century at a time of growing carbon emissions from fossil fuel burning. Here we test the hypothesis that increases in atmospheric aerosols from fossil fuel burning enhanced the diffuse light fraction and the efficiency of plant carbon uptake. Using a combination of models, we estimate that at global scale changes in light regimes from fossil fuel aerosol emissions had only a small negative effect on the increase in terrestrial net primary production over the period 1998–2010. Hereby, the substantial increases in fossil fuel aerosol emissions and plant carbon uptake over East Asia were effectively canceled by opposing trends across Europe and North America. This suggests that if the recent increase in the land carbon sink would be causally linked to fossil fuel emissions, it is unlikely via the effect of aerosols but due to other factors such as nitrogen deposition or nitrogen‐carbon interactions.
Remote influence of Interdecadal Pacific Oscillation on the South Atlantic meridional overturning circulation variability
Authors: Lopez Hosmay , Dong Shenfu , Lee Sang‐Ki , Campos Edmo 
Published: August 2016

AbstractThis study explores potential factors that may influence decadal variability of the South Atlantic meridional overturning circulation (SAMOC) by using observational data as well as surface‐forced ocean model runs and a fully coupled climate model run. Here we show that SAMOC is strongly correlated with the leading mode of sea surface height (SSH) variability in the South Atlantic Ocean, which displays a meridional dipole between north and south of 20°S. A significant portion (~45%) of the South Atlantic SSH dipole variability is remotely modulated by the Interdecadal Pacific Oscillation (IPO). Further analysis shows that anomalous tropical Pacific convection associated with the IPO forces robust stationary Rossby wave patterns, modulating the wind stress curl over the South Atlantic Ocean. A positive (negative) phase IPO increases (decreases) the westerlies over the South Atlantic, which increases (decreases) the strength of the subtropical gyre in the South Atlantic and thus the SAMOC.
A novel algorithm for monitoring reservoirs under all‐weather conditions at a high temporal resolution through passive microwave remote sensing
Authors: Zhang Shuai , Gao Huilin 
Published: August 2016

AbstractFlood mitigation in developing countries has been hindered by a lack of near real‐time reservoir storage information at high temporal resolution. By leveraging satellite passive microwave observations over a reservoir and its vicinity, we present a globally applicable new algorithm to estimate reservoir storage under all‐weather conditions at a 4 day time step. A weighted horizontal ratio (WHR) based on the brightness temperatures at 36.5 GHz is introduced, with its coefficients calibrated against an area training data set over each reservoir. Using a predetermined area‐elevation (A‐H) relationship, these coefficients are then applied to the microwave data to calculate the storage. Validation results over four reservoirs in South Asia indicate that the microwave‐based storage estimations (after noise reduction) perform well (with coefficients of determination ranging from 0.41 to 0.74). This is the first time that passive microwave observations are fused with other satellite data for quantifying the storage of individual reservoirs.
Climatic consequences of adopting drought‐tolerant vegetation over Los Angeles as a response to California drought
Authors: Vahmani P. , Ban‐Weiss G. 
Published: August 2016

AbstractDuring 2012–2014, drought in California resulted in policies to reduce water consumption. One measure pursued was replacing lawns with landscapes that minimize water consumption, such as drought‐tolerant vegetation. If implemented at broad scale, this strategy would result in reductions in irrigation and changes in land surface characteristics. In this study, we employ a modified regional climate model to assess the climatic consequences of adopting drought‐tolerant vegetation over the Los Angeles metropolitan area. Transforming lawns to drought‐tolerant vegetation resulted in daytime warming of up to 1.9°C, largely due to decreases in irrigation that shifted surface energy partitioning toward higher sensible and lower latent heat flux. During nighttime, however, adopting drought‐tolerant vegetation caused mean cooling of 3.2°C, due to changes in soil thermodynamic properties and heat exchange dynamics between the surface and subsurface. Our results show that nocturnal cooling effects, which are larger in magnitude and of great importance for public health during heat events, could counterbalance the daytime warming attributed to the studied water conservation strategy. A more aggressive implementation, assuming all urban vegetation was replaced with drought‐tolerant vegetation, resulted in an average daytime cooling of 0.2°C, largely due to strengthened sea breeze patterns, highlighting the important role of land surface roughness in this coastal megacity.
Slip model of the 17 November 2015 Mw = 6.5 Lefkada earthquake from the joint inversion of geodetic and seismic data
Authors: Chousianitis Konstantinos , Konca A. Ozgun , Tselentis G.‐Akis , Papadopoulos Gerassimos A. , Gianniou Michail 
Published: August 2016

AbstractWe inferred the rupture process of the 2015 Lefkada earthquake by combining teleseismic and near‐field strong motion data, together with static and dynamic GPS displacements. The joint inversion of all data sets revealed a relatively complex slip pattern with a heterogeneous distribution. Slip is confined in the upper 10 km. Two principal asperities with peak slip amplitude of 2.35 m, which released 65% of the total seismic moment, were recovered southwest of the epicenter. Remarkably, the 2015 earthquake ruptured the part of the Cephalonia Transform Fault Zone that remained unbroken during the 2003 event, revealing a pattern of rupture segmentation along the fault zone. In this context the Lefkada segment can be divided into a northern and southern part. Preseismic deformation onshore southern Lefkada revealed that since the 2003 rupture, the northern part of the Lefkada segment continuously loaded the southern part, which eventually broke during the 2015 event.
SMAP soil moisture drying more rapid than observed in situ following rainfall events
Authors: Shellito Peter J. , Small Eric E. , Colliander Andreas , Bindlish Rajat , Cosh Michael H. , Berg Aaron A. , Bosch David D. , Caldwell Todd G. , Goodrich David C. , McNairn Heather , Prueger John H. , Starks Patrick J. , van der Velde Rogier , Walker Jeffrey P. 
Published: August 2016

AbstractWe examine soil drying rates by comparing surface soil moisture observations from the NASA Soil Moisture Active Passive (SMAP) mission to those from networks of in situ probes upscaled to SMAP's sensing footprint. SMAP and upscaled in situ probes record different soil drying dynamics after rainfall. We modeled this process by fitting an exponential curve to 63 drydown events: the median SMAP drying timescale is 44% shorter and the magnitude of drying is 35% greater than in situ measurements. We also calculated drying rates between consecutive observations from 193 events. For 6 days after rainfall, soil moisture from SMAP dries at twice the rate of in situ measurements. Restricting in situ observations to times of SMAP observations does not change the drying timescale, magnitude, or rate. Therefore, observed differences are likely due to differences in sensing depths: SMAP measures shallower soil moisture than in situ probes, especially after rainfall.
Fast modulations of pulsating proton aurora related to subpacket structures of Pc1 geomagnetic pulsations at subauroral latitudes
Authors: Ozaki M. , Shiokawa K. , Miyoshi Y. , Kataoka R. , Yagitani S. , Inoue T. , Ebihara Y. , Jun C.‐W , Nomura R. , Sakaguchi K. , Otsuka Y. , Shoji M. , Schofield I. , Connors M. , Jordanova V. K. 
Published: August 2016

AbstractTo understand the role of electromagnetic ion cyclotron (EMIC) waves in determining the temporal features of pulsating proton aurora (PPA) via wave‐particle interactions at subauroral latitudes, high‐time‐resolution (1/8 s) images of proton‐induced N2+ emissions were recorded using a new electron multiplying charge‐coupled device camera, along with related Pc1 pulsations on the ground. The observed Pc1 pulsations consisted of successive rising‐tone elements with a spacing for each element of 100 s and subpacket structures, which manifest as amplitude modulations with a period of a few tens of seconds. In accordance with the temporal features of the Pc1 pulsations, the auroral intensity showed a similar repetition period of 100 s and an unpredicted fast modulation of a few tens of seconds. These results indicate that PPA is generated by pitch angle scattering, nonlinearly interacting with Pc1/EMIC waves at the magnetic equator.
MMS observations of ion‐scale magnetic island in the magnetosheath turbulent plasma
Authors: Huang S. Y. , Sahraoui F. , Retino A. , Le Contel O. , Yuan Z. G. , Chasapis A. , Aunai N. , Breuillard H. , Deng X. H. , Zhou M. , Fu H. S. , Pang Y. , Wang D. D. , Torbert R. B. , Goodrich K. A. , Ergun R. E. , Khotyaintsev Y. V. , Lindqvist P.‐A. , Russell C. T. , Strangeway R. J. , Magnes W. , Bromund K. , Leinweber H. , Plaschke F. , Anderson B. J. , Pollock C. J. , Giles B. L. , Moore T. E. , Burch J. L. 
Published: August 2016

AbstractIn this letter, first observations of ion‐scale magnetic island from the Magnetospheric Multiscale mission in the magnetosheath turbulent plasma are presented. The magnetic island is characterized by bipolar variation of magnetic fields with magnetic field compression, strong core field, density depletion, and strong currents dominated by the parallel component to the local magnetic field. The estimated size of magnetic island is about 8 di, where di is the ion inertial length. Distinct particle behaviors and wave activities inside and at the edges of the magnetic island are observed: parallel electron beam accompanied with electrostatic solitary waves and strong electromagnetic lower hybrid drift waves inside the magnetic island and bidirectional electron beams, whistler waves, weak electromagnetic lower hybrid drift waves, and strong broadband electrostatic noise at the edges of the magnetic island. Our observations demonstrate that highly dynamical, strong wave activities and electron‐scale physics occur within ion‐scale magnetic islands in the magnetosheath turbulent plasma.
Evidence for universal earthquake rupture initiation behavior
Authors: Meier Men‐Andrin , Heaton Thomas , Clinton John 
Published: August 2016

AbstractEarthquake onsets provide a unique opportunity to study physical rupture processes because they are more easily observable than later rupture stages. Despite this relative simplicity, the observational basis for rupture onsets is unclear. Numerous reports of evidence for magnitude‐dependent rupture onsets (which imply deterministic rupture behavior) stand in contradiction to a large body of physics‐based rupture modeling efforts, which are mostly based on inherently nondeterministic principles. Here we make use of the abundance of short‐distance recordings available today; a magnitude dependency of onsets should appear most prominently in such recordings. We use a simple method to demonstrate that all ruptures in the studied magnitude range (4 < M < 8) share a universal initial rupture behavior and discuss ensuing implications for physical rupture processes and earthquake early warning.