bluuebunny/crossref_metadata_2025_split huggingface dataset:
The benefits of using remotely sensed soil moisture in parameter identification of large‐scale hydrological models
Authors: Wanders N. , Bierkens M. F. P. , de Jong S. M. , de Roo A. , Karssenberg D. 
Published: August 2014

AbstractLarge‐scale hydrological models are nowadays mostly calibrated using observed discharge. As a result, a large part of the hydrological system, in particular the unsaturated zone, remains uncalibrated. Soil moisture observations from satellites have the potential to fill this gap. Here we evaluate the added value of remotely sensed soil moisture in calibration of large‐scale hydrological models by addressing two research questions: (1) Which parameters of hydrological models can be identified by calibration with remotely sensed soil moisture? (2) Does calibration with remotely sensed soil moisture lead to an improved calibration of hydrological models compared to calibration based only on discharge observations, such that this leads to improved simulations of soil moisture content and discharge? A dual state and parameter Ensemble Kalman Filter is used to calibrate the hydrological model LISFLOOD for the Upper Danube. Calibration is done using discharge and remotely sensed soil moisture acquired by AMSR‐E, SMOS, and ASCAT. Calibration with discharge data improves the estimation of groundwater and routing parameters. Calibration with only remotely sensed soil moisture results in an accurate identification of parameters related to land‐surface processes. For the Upper Danube upstream area up to 40,000 km2, calibration on both discharge and soil moisture results in a reduction by 10–30% in the RMSE for discharge simulations, compared to calibration on discharge alone. The conclusion is that remotely sensed soil moisture holds potential for calibration of hydrological models, leading to a better simulation of soil moisture content throughout the catchment and a better simulation of discharge in upstream areas.
Deep ocean early warning signals of an Atlantic MOC collapse
Authors: Feng Qing Yi , Viebahn Jan P. , Dijkstra Henk A. 
Published: August 2014

AbstractA future collapse of the Atlantic Meridional Overturning Circulation (MOC) has been identified as one of the most dangerous tipping points in the climate system. It is therefore crucial to develop early warning indicators for such a potential collapse based on relatively short time series. So far, attempts to use indicators based on critical slowdown have been marginally successful. Based on complex climate network reconstruction, we here present a promising new indicator for the MOC collapse that efficiently monitors spatial changes in deep ocean circulation. Through our analysis of the performance of this indicator, we formulate optimal locations of measurement of the MOC to provide early warning signals of a collapse. Our results imply that an increase in spatial resolution of the Atlantic MOC observations (i.e., at more sections) can improve early detection, because the spatial coherence in the deep ocean arising near the transition is better captured.
Evolution of mass density and O+ concentration at geostationary orbit during storm and quiet events
Authors: Denton R. E. , Takahashi K. , Thomsen M. F. , Borovsky J. E. , Singer H. J. , Wang Y. , Goldstein J. , Brandt P. C. , Reinisch B. W. 
Published: August 2014

AbstractWe investigated mass density ρm and O+ concentration ηO+≡nO+/ne (where nO+ and ne are the O+ and electron density, respectively) during two events, one active and one more quiet. We found ρm from observations of Alfvén wave frequencies measured by the GOES, and we investigated composition by combining measurements of ρm with measurements of ion density nMPA,i from the Magnetospheric Plasma Analyzer (MPA) instrument on Los Alamos National Laboratory spacecraft or ne from the Radio Plasma Imager instrument on the Imager for Magnetopause‐to‐Aurora Global Exploration spacecraft. Using a simple assumption for the He+ density at solar maximum based on a statistical study, we found ηO+ values ranging from near zero to close to unity. For geostationary spacecraft that corotate with the Earth, sudden changes in density for both ρm and ne often appear between dusk and midnight magnetic local time, especially when Kp is significantly above zero. This probably indicates that the bulk (total) ions have energy below a few keV and that the satellites are crossing from closed or previously closed to open drift paths. During long periods that are geomagnetically quiet, the mass density varies little, but ne gradually refills leading to a gradual change in composition from low‐density plasma that is relatively cold and heavy (high‐average ion mass M ≡ ρm/ne) to high‐density plasma that is relatively cold and light (low M) plasmasphere‐like plasma. During active periods we observe a similar daily oscillation in plasma properties from the dayside to the nightside, with cold and light high‐density plasma (more plasmasphere‐like) on the dayside and hotter and more heavy low‐density plasma (more plasma sheet‐like) on the nightside. The value of ne is very dependent on whether it is measured inside or outside a plasmaspheric plume, while ρm is not. All of our results were found at solar maximum; previous results suggest that there will be much less O+ at solar minimum under all conditions.
Mush microphysics and the reactivation of crystal‐rich magma reservoirs
Authors: Parmigiani Andrea , Huber Christian , Bachmann Olivier 
Published: August 2014

AbstractReactivation and eruption of upper crustal crystal‐rich magma reservoirs (“crystal mushes”) following recharge has recently been invoked in numerous volcanic systems worldwide. Over the last few years, several models have been proposed for the reactivation of such mushes prior to or during eruptions. These models vary significantly in terms of predicted timescales associated with reactivation, because they assume that different physical mechanisms control the dynamics of this process. A common limitation of all the proposed models is that they parameterize the complex nonlinear multiphase dynamics that govern the evolution of these magmas in their open system reservoirs and rely on simple empirical laws. We argue that microscale physical models are a necessity if one wants to better constrain the evolution of these complex systems and the conditions that lead to eruption. As petrological observations of erupted mushes strongly support a thermal and fluid input from wet magma recharges, we have developed a pore‐scale multiphase heat and fluid transport model to understand the effect of a percolating fluid phase on the partial melting and reactivation of crystal mushes. Specifically, we use lattice Boltzmann calculations to reveal a counterintuitive feedback between volatile transport and melting in crystal‐rich environments. We find that partial melting, even at a low degree, can significantly reduce the efficiency of the buoyant migration of exsolved volatiles in the mush and therefore negatively impact the heat transfer upward during reactivation. This negative feedback between melting and volatile transport is expected to significantly affect the distribution of exsolved volatiles in the reservoirs, as well as the transport of trace species carried by the volatile phase (e.g., S, metals). The presence of a disperse magmatic volatile phase (unconnected bubbles) will also affect the thermomechanical properties of the mush during reactivation, making it more compressible and thermally less conductive.
Rupture and variable coupling behavior of the Mentawai segment of the Sunda megathrust during the supercycle culmination of 1797 to 1833
Authors: Philibosian Belle , Sieh Kerry , Avouac Jean‐Philippe , Natawidjaja Danny H. , Chiang Hong‐Wei , Wu Chung‐Che , Perfettini Hugo , Shen Chuan‐Chou , Daryono Mudrik R. , Suwargadi Bambang W. 
Published: August 2014

AbstractWe refer to periods of subduction strain accumulation beneath the Mentawai Islands, Sumatra, as “supercycles,” because each culminates in a series of partial ruptures of the megathrust in its final decades. The finale of the previous supercycle comprised two giant earthquakes in 1797 and 1833 and whatever happened in between. This behavior between two great ruptures has implications for how the megathrust will behave between its more recent partial failure, during the Mw 8.4 earthquake of 2007, and subsequent large ruptures. We synthesize previously published coral microatoll records and a large new coral data set to constrain not only these two giant ruptures but also the intervening interseismic megathrust behavior. We present detailed maps of coseismic uplift during the two earthquakes and of interseismic deformation during the periods 1755–1833 and 1950–2000, as well as models of the corresponding slip and coupling on the underlying megathrust. The large magnitudes we derive (Mw 8.6–8.8 for 1797 and Mw 8.8–8.9 for 1833) confirm that the 2007 earthquakes released only a fraction of the moment released during the previous rupture sequence. Whereas megathrust behavior leading up to the 1797 and 2007 earthquakes was similar and comparatively simple, behavior between 1797 and 1833 was markedly different and more complex: several patches of the megathrust became weakly coupled following the 1797 earthquake. We conclude that while major earthquakes generally do not involve rupture of the entire Mentawai segment, they may significantly change the state of coupling on the megathrust for decades to follow, influencing the progression of subsequent ruptures.
Real‐time retrieval of precipitable water vapor from GPS precise point positioning
Authors: Yuan Yubin , Zhang Kefei , Rohm Witold , Choy Suelynn , Norman Robert , Wang Chuan‐Sheng 
Published: August 2014

AbstractSensing of precipitable water vapor (PWV) using the Global Positioning System (GPS) has been intensively investigated in the past 2 decades. However, it still remains a challenging task at a high temporal resolution and in the real‐time mode. In this study the accuracy of real‐time zenith total delay (ZTD) and PWV using the GPS precise point positioning (PPP) technique is investigated. GPS observations in a 1 month period from 20 globally distributed stations are selected for testing. The derived real‐time ZTDs at most stations agree well with the tropospheric products from the International Global Navigation Satellite Systems Service, and the root‐mean‐square errors (RMSEs) are <13 mm, which meet the threshold value of 15 mm if ZTDs are input to numerical weather prediction models. The RMSE of the retrieved PWVs in comparison with the radiosonde‐derived values are ≤3 mm, which is the threshold RMSE of PWVs as inputs to weather nowcasting. The theoretical accuracy of PWVs is also discussed, and 3 mm quality of PWVs is proved achievable in different temperature and humidity conditions. This implies that the real‐time GPS PPP technique can be complementary to current atmospheric sounding systems, especially for nowcasting of extreme weather due to its real‐time, all‐day, and all‐weather capabilities and high temporal resolutions.
On the use of modified Taylor diagrams to compare ionospheric assimilation models
Authors: Elvidge S. , Angling M. J. , Nava B. 
Published: August 2014

AbstractThis paper describes the construction and use of “modified Taylor diagrams” and the comparison of three real‐time assimilative ionospheric models. The paper expands on the work by McNamara et al. (2013) and serves as an addendum to that work. Modified Taylor diagrams provide an easy way of visualizing and comparing statistical information about a number of models, and for multiple parameters, simultaneously. Using modified Taylor diagrams has led to new conclusions about the models tested in McNamara et al. (2013); also, the comparison of the data ingestion version of NeQuick is included. It is shown that the modified NeQuick model performs comparably with the data assimilation models from McNamara et al. (2013) and in multiple cases also shows considerable improvement, such as in hmF2 at the Hermanus Digisonde station.
Spatial distribution and temporal variations of occurrence frequency of lightning whistlers observed by VLF/WBA onboard Akebono
Authors: Oike Yuta , Kasahara Yoshiya , Goto Yoshitaka 
Published: August 2014

AbstractWe statistically analyzed lightning whistlers detected from the analog waveform data below 15 kHz observed by the VLF instruments onboard Akebono. We examined the large amount of data obtained at Uchinoura Space Center in Japan for 22 years from 1989 to 2010. The lightning whistlers were mainly observed inside the L shell region below 2. Seasonal dependence of the occurrence frequency of lightning whistlers has two peaks around July to August and December to January. As lightning is most active in summer, in general, these two peaks correspond to summer in the Northern and Southern Hemispheres, respectively. Diurnal variation of the occurrence frequency showed that lightning whistlers begin to increase in the early evening and remain at a high‐occurrence level through the night with a peak around 21 in magnetic local time (MLT). This peak shifts toward nightside compared with lightning activity, which begins to rise around noon and peaks in the late afternoon. This trend is supposed to be caused by attenuation of VLF wave in the ionosphere in the daytime. Comparison study with the ground‐based observation revealed consistent results, except that the peak of the ground‐based observation appeared after midnight while our measurements obtained by Akebono was around 21 in MLT. This difference is explained qualitatively in terms that lightning whistlers measured at the ground station passed through the ionosphere twice above both source region and the ground station. These facts provide an important clue to evaluate quantitatively the absorption effect of lightning whistler in the ionosphere.
Hydrologic routing using nonlinear cascaded reservoirs
Authors: Kim Dong Ha , Georgakakos Aris P. 
Published: August 2014

AbstractA key element of hydrologic routing models is that the discharge‐storage relationship is assumed to follow a certain mathematical form, usually a linear or a power function, with parameters calibrated based on existing inflow‐outflow data. This assumption simplifies the model calibration process but also constrains model operation throughout the flow range, potentially introducing biases. We present a new nonlinear hydrologic river routing approach where functions are only required to be nondecreasing. River reaches are modeled as conceptual reservoir cascades, with discharge‐storage and loss/gain functions identified by the data. A novel parameter estimation approach is developed to identify these functions and other model parameters within a dynamical optimization framework. It is shown that hydrologic routing functions indeed exhibit different mathematical forms at different regions of their active range, and that the new approach is reliable, efficient, and robust under observational uncertainty. The model is demonstrated in lake and river routing applications for the Nile River, and it is also applicable for the estimation of nonlinear, nondecreasing functional relationships of general dynamic systems in state‐space form.
Chemistry of Marine Natural Substances: Originality, Diversity, Distribution
Authors: Kornprobst Jean‐Michel 
Published: August 2014

AbstractThe article contains sections titled:General IntroductionDistribution of Nitrogenous and Non‐Nitrogenous Secondary MetabolitesDistribution of Secondary Metabolites by Chemical ClassCharacteristics of the Secondary Metabolites of Marine OrganismsIncorporation of HalogensIncorporation of SulfurIncorporation of SiliconRare Chemical Elements Encountered in Marine Substances:As,B,Ni,V,ZnArsenicBoronNickelVanadiumZinc
Archaea
Authors: Kornprobst Jean‐Michel 
Published: August 2014

AbstractThe article contains sections titled:General IntroductionMembrane LipidsMacrocyclic Dialkyl Glycerol DiethersPaleotemperatures Index:TEX86andBITIndexPranylquinonesCyclic PolysulfidesBacteriorhodopsin of HalophilesExtremozymes
Thraustochytrids and Ciliates
Authors: Kornprobst Jean‐Michel 
Published: August 2014

AbstractThe article contains sections titled:Taxonomic Position of Thraustochytrids and Overview of the GroupCarotenoids of ThraustochytridsLong‐Chain (n‐3) Polyunsaturated Fatty Acids of ThraustochytridsLong‐Chain Fatty Acid Composition and Phylogeny of Thraustochytridsα‐Glucosylceramides of ThraustochytridsExtracellular EnzymesIntroduction to the Chemistry of CiliatesTerpenes ofEuplotesPhotoreceptor PigmentsKeronopsins and Keronopsamides ofPseudokeronopsis rubraandP. ricii
Introduction to Chemical Ecology
Authors: Kornprobst Jean‐Michel 
Published: August 2014

AbstractThe article contains sections titled:Examples of Intraspecific RelationsSexual Pheromones: Sperm‐Activating Peptides of Urchins and MollusksExamples of Alarm PheromonesExamples of Interspecific RelationshipsPredator–Prey Relationships: Defense Allomones of Algae and InvertebratesDefense Allomones in Associations Between Microorganisms and InvertebratesElicitors and Defense Allomones of AlgaeSubstances Inducing Metamorphosis of LarvaeFormation of Epibiosis (Biofouling) and Antifouling SubstancesFood Attractants and Stimulants
Contributions of Familial Rheumatoid Arthritis or Lupus and Environmental Factors to Risk of Rheumatoid Arthritis in Women: A Prospective Cohort Study
Authors: Sparks Jeffrey A. , Chen Chia‐Yen , Hiraki Linda T. , Malspeis Susan , Costenbader Karen H. , Karlson Elizabeth W. 
Published: August 2014

ObjectiveWe assessed the contributions of familial rheumatoid arthritis (RA) or lupus and environmental factors to the risk of RA.MethodsAmong 121,700 women in the Nurses' Health Study, 65,457 provided data on familial RA/lupus. Among these, 493 RA cases (301 seropositive and 192 seronegative) were validated. We estimated hazard ratios (HRs) for RA comparing those with and without familial RA/lupus, adjusting for environmental factors (smoking, alcohol, body mass index [BMI], parity, breastfeeding, menopause, hormone use, early menarche, and menstrual regularity) using Cox proportional hazards models. Population attributable risks (PARs) for RA within this cohort were calculated for familial RA/lupus, smoking, alcohol, BMI, parity, and breastfeeding.ResultsFamilial RA/lupus was significantly associated with RA (HR 3.67), seropositive RA (HR 3.90), and seronegative RA (HR 3.95). After adjusting for environmental factors, familial RA/lupus was significantly associated with RA (HR 3.59, 95% confidence interval 2.94–4.37). Smoking >10 pack‐years, overweight, BMI, and premenopause status remained significantly associated with RA after adjusting for familial RA/lupus. For RA in this cohort, the PAR for smoking, BMI, alcohol, parity, or breastfeeding collectively was 41%; the PAR due to heredity from familial RA/lupus was 21%.ConclusionIn this large, prospective cohort, women with familial RA/lupus had a 4‐fold increased risk for RA that remained significant after adjusting for environmental factors. A large proportion of RA risk was attributable to environmental factors, even among those with familial RA/lupus.
Brief Communication: A likely case of scurvy in a rural Early Classic Maya burial from Actun Uayazba Kab, Belize
Authors: Wrobel Gabriel 
Published: August 2014

ABSTRACTA Maya burial of a late adolescent (Burial 98‐3) found in the rockshelter entrance of Actun Uayazba Kab (AUK), Belize, displays a combination of lesions that is consistent with scurvy. Signs include large, active lesions on the posterior surfaces of maxilla; relatively mild porotic hyperostosis along the midline of the skull on the parietals and occipital; cribra orbitalia; potential pinprick lesions on the greater wings of sphenoid and temporal; reactive lesions on the palate, temporal lines of frontal and parietals, and external and internal surfaces of zygomatics; small lesions on the popliteal surfaces of both femora; and periodontal disease. Identification of scurvy at AUK potentially informs the analysis of other primary burials and scattered bone found there and at other nearby sites, which often reveal evidence of nonspecific lesions that are usually attributed to anemia and infection, but that are also consistent with scurvy. The social and ecological context of this Protoclassic (0–AD 300) individual, who lived in a rural agricultural community with no evidence of complex social hierarchy, contrasts with typical discussions of disease among the Maya, which tend to focus on the degrading effects of overcrowding and resource deficiencies. While scurvy has been largely overlooked in the Maya area, this study supports earlier arguments for its presence that were based largely on clinical and ethnographic analogies and suggests the need to incorporate scurvy into broader synergistic models of ancient health. Am J Phys Anthropol 155:476–481, 2014. © 2014 Wiley Periodicals, Inc.
Comparison study of the polar cold air mass between Northern and Southern Hemispheric winters based on a zonal‐mean two‐box model
Authors: Kanno Yuki , Shoji Takamichi , Iwasaki Toshiki 
Published: August 2014

AbstractThe characteristics of the polar cold air mass (PCAM) below a threshold potential temperature θT are quantitatively compared between two hemispheric winters and analyzed with a zonal‐mean two‐box model. This model estimates a residence time in a genesis box, a life time in a loss box, and PCAM flux between them. The hemispheric total PCAM amount below θT =280 K in the Northern Hemispheric winter is approximately 40% greater than that in the Southern Hemispheric winter. This difference is attributed to the residence time enhanced due to the land–sea distribution and mountain barriers, while the PCAM flux is almost equivalent between the two winters.
An Overview of Industrial Processes for the Production of Olefins – C4 Hydrocarbons
Authors: Bender Michael 
Published: August 2014

AbstractThe survey describes industrial processes for the production of light olefins emphasizing on C4 hydrocarbons. Value chains in the petrochemical and the oil refining industry are strongly interrelated with regards to olefin production. An account is given on the production and the consumption volumes of the various C4 hydrocarbons on a global basis, including an outlook for alternative, petrochemical and bio‐based processes for the production of C4 olefins.
ChemInform Abstract: Thermochemical Investigations in the System Cd—Gd.
Authors: Reichmann Thomas L. , Ganesan Rajesh , Ipser Herbert 
Published: August 2014

AbstractThe vapor pressure of Cd in the Cd—Gd system is determined between 693 and 1045 K, and the thermodynamic activities of Cd are derived as a function of temperature for the composition range 52—86 wt.% Cd.
ChemInform Abstract: H2V3O8 Nanobelts as a Novel Stable Electrode Material with Good Reversible Redox Performance.
Authors: Mjejri I. , Etteyeb N. , Sediri F. 
Published: August 2014

AbstractBelt‐like nanocrystalline H2V3O8 is hydrothermally synthesized from a mixture of V2O5, 1,4‐butanediol, and water in the molar ratio 1:0.5:277 (autoclave, 180 °C, 4 d).
ChemInform Abstract: [Sb7Se8Br2]3+ and [Sb13Se16Br2]5+ — Double and Quadruple Spiro Cubanes from Ionic Liquids.
Authors: Ahmed Ejaz , Breternitz Joachim , Groh Matthias F. , Isaeva Anna , Ruck Michael 
Published: August 2014

AbstractThe new compounds obtained by reaction of Sb and Se in ionic liquids are characterized by single crystal XRD and DFT quantum chemical calculations.
ChemInform Abstract: Experimental and First‐Principles Studies of the Ternary Borides Ta3Ru5B2 and M3‐xRu5+xB2 (M: Zr, Hf).
Authors: Hermus Martin , Fokwa Boniface P. T. 
Published: August 2014

AbstractThe ternary borides Ta3Ru5B2, Zr2.86Ru5.14B2, and Hf2.83Ru5.17B2 are synthesized by arc‐melting of stoichiometric mixtures of the elements (Ar, Cu crucibles).