bluuebunny/crossref_metadata_2025 huggingface dataset:
On estimating Gross Primary Productivity of Mediterranean grasslands under different fertilization regimes using vegetation indices and hyperspectral reflectance
Authors: Cerasoli Sofia , Campagnolo Manuel , Faria Joana , Nogueira Carla , Caldeira Maria
Published: March 2018

Abstract. We applied an empirical modelling approach for Gross Primary Productivity (GPP) estimation from hyperspectral surface reflectance of Mediterranean grasslands undergoing different fertilization treatments. The objective of the study was to identify combinations of vegetation indices and bands that better represent GPP changes between the annual-peak of growth and senescence dry out in Mediterranean grasslands. In situ, hyperspectral measurements of vegetation reflectance, were collected at the same time as CO2 gas exchange measurements were performed in control (C) and fertilized plots with added nitrogen (N), phosphorus (P) or the combination of N, P and potassium (NPK). Reflectance values were aggregated, according to their similarity (r > 90 %), in 26 continuous wavelength intervals (Hyp). Also, the same reflectance values were resampled reproducing the wavebands of both Sentinel-2A Multispectral Instrument (S2) and Landsat 8 Operation Land Imager (L8). This lead to a set of reflectance values simulating the signal that would be captured in ideal conditions by either Sentinel-2A or Landsat 8. The LEAPS procedure was applied to select the best set of the vegetation indices or spectral bands for GPP estimation using Hyp, S2 or L8. The LEAPS selected some vegetation indices putting in evidence their exploratory power as indicators of the dynamic changes of community vegetation properties such as canopy water content (NDWI) or chlorophyll and carotenoids/chlorophyll ratio (MTCI, PSRI, GNDVI), underlining their importance for grasslands GPP estimates. For Hyp and S2, spectral bands showed similar exploratory power than vegetation indices to estimate GPP. A two-step LEAPS procedure allowed us also to identify spectral bands with potential for improving GPP estimates. This procedure clearly indicates the shortwave infrared region of the spectra as promising for this purpose. The comparison of S2 and L8 based models showed similar explanatory power of the two simulated satellite sensors when spectral bands were adopted. Altogether our results show the potential of sensors on board of Sentinel 2 and Landsat 8 satellites for monitoring grasslands phenology and improving GPP estimates in support of a sustainable agriculture management.
Uncertainties in projections of the Baltic Sea ecosystem driven by an ensemble of global climate models
Authors: Saraiva Sofia , Meier H. E. Markus , Andersson Helén , Höglund Anders , Dieterich Christian , Hordoir Robinson , Eilola Kari
Published: March 2018

Abstract. Many coastal seas worldwide are affected by human impacts such as eutrophication, causing, inter alia, oxygen depletion and extensive areas of hypoxia. Depending on the region, global warming may reinforce these environmental changes by reducing air–sea oxygen fluxes, intensifying internal nutrient cycling and increasing river-borne nutrient loads. The development of appropriate management plans to more effectively protect the marine environment requires projections of future marine ecosystem states. However, projections with regional climate models commonly suffer from shortcomings in the driving global General Circulation Models (GCMs). The differing sensitivities of GCMs to increased greenhouse gas emissions impact regional projections considerably. In this study, we focused on one of the most threatened coastal seas, the Baltic Sea, and estimated uncertainties in projections due to GCM deficiencies relative to uncertainties caused by future greenhouse gas emissions and nutrient load scenarios. To address the latter, transient simulations of the period 1975–2098 were performed using the initial conditions from an earlier reconstruction with the same Baltic Sea model (starting in 1850). To estimate the impacts of GCM deficiencies, dynamical downscaling experiments with four driving global models were carried out for two greenhouse gas emission scenarios, RCP4.5 and 8.5, and for three nutrient load scenarios covering the plausible range between low and high loads. The results of primary production, nitrogen fixation, and hypoxic areas show that uncertainties caused by the various nutrient load scenarios are greater than the uncertainties due to global model deficiencies and future greenhouse gas emissions. In all scenario simulations, a proposed nutrient load abatement strategy, i.e., the Baltic Sea Action Plan, will lead to a significant improvement in the overall environmental state. However, the projections cannot provide detailed information on the timing and the reductions of future hypoxic areas due to uncertainties in salinity projections caused by uncertainties in projections of the regional water cycle and of the global mean sea level rise.
An inventory of Arctic Ocean data in the World Ocean Database
Authors: Zweng Melissa M. , Boyer Tim P. , Baranova Olga K. , Reagan James R. , Seidov Dan , Smolyar Igor V.
Published: March 2018

Abstract. The World Ocean Database (WOD) contains over 1.3 million oceanographic casts (where cast refers to an oceanographic profile or set of profiles collected concurrently at more than one depth between the ocean surface and ocean bottom) collected in the Arctic Ocean basin and its surrounding marginal seas. The data, collected from 1849 to the present, come from many submitters and countries, and were collected using a variety of instruments and platforms. These data, along with the derived products World Ocean Atlas (WOA) and the Arctic Regional Climatologies, are exceptionally useful – the data are presented in a standardized, easy to use format and include metadata and quality control information. Collecting data in the Arctic Ocean is challenging, and coverage in space and time ranges from excellent to nearly non-existent. WOD continues to compile a comprehensive collection of Arctic Ocean profile data, ideal for oceanographic, environmental and climatic analyses (https://doi.org/10.7289/V54Q7S16).
Dynamic hydrological discharge modelling for coupled climate
model simulations of the last glacial cycle
Authors: Riddick Thomas , Brovkin Victor , Hagemann Stefan , Mikolajewicz Uwe
Published: March 2018

Abstract. The continually evolving large ice sheets present in the Northern Hemisphere during the last glacial cycle caused significant changes to river pathways both through directly blocking rivers and through glacial isostatic adjustment. Studies have shown these river pathway changes had a significant impact on the ocean circulation through changing the pattern of freshwater discharge into the oceans. A coupled Earth System Model (ESM) simulation of the last glacial cycle thus requires a hydrological discharge model that uses a set of river pathways that evolve with Earth's changing orography while being able to reproduce the known present-day river network given the present-day orography. Here we present a method for dynamically modelling river pathways that meets such requirements by applying pre-defined corrections to an evolving fine scale orography (accounting for the changing ice sheets and isostatic rebound) each time the river directions are recalculated. The corrected orography thus produced is then used to create a set of fine scale river pathways and these are then upscaled to a coarser scale on which an existing present-day hydrological discharge model within the JSBACH land surface model simulates the river flow. Tests show that this procedure reproduces the known present-day river network to a sufficient degree of accuracy and is able to simulate plausible paleo river networks. It has also been shown this procedure can be run successfully multiple times as part of a transient coupled climate model simulation.
Baseline Evaluation of the Impact of Updates to the MIT Earth System Model on its Model Parameter Estimates
Authors: Libardoni Alex G. , Forest Chris E. , Sokolov Andrei P. , Monier Erwan
Published: March 2018

Abstract. For over twenty years, the Massachusetts Institute of Technology Earth System Model (MESM) has been used extensively for climate change research. The model is under continuous development with components being added or updated. To provide transparency in the model development, we perform a baseline evaluation of the newest version by comparing model behavior and properties to the previous model version. In particular, the impacts resulting from updates to the land surface model component and the input forcings used in historical simulations of climate change are investigated. We run an 1800-member ensemble of MESM historical climate simulations where the model parameters that set climate sensitivity, ocean heat uptake, and the net anthropogenic aerosol forcing are systematically varied. By comparing model output to observed patterns of surface temperature changes, the linear trend in the increase in ocean heat content, and upper-air temperature changes, we derive probability distributions for the three model parameters. Furthermore, we run a 372-member ensemble of transient climate simulations where model forcings are held fixed, absent an increase in carbon dioxide concentrations at the rate of 1 % per year. From these runs, we derive a response surface for transient climate response and thermosteric sea level rise as a function of climate sensitivity and ocean heat uptake. We compare the probability distributions and response surfaces derived using the current version of MESM to the preceding version to evaluate the impact of the updated land surface model and forcing suite. We show that the probability distributions shift towards higher climate sensitivities and weaker aerosol forcing in response to the new forcing suite. The climate response surfaces are relatively unchanged between model versions, indicating that the updated land surface model has limited impact on temperature evolution in the model.
Inundation mapping based on reach-scale effective geometry
Authors: Rebolho Cédric , Andréassian Vazken , Le Moine Nicolas
Published: March 2018

Abstract. The production of spatially accurate representations of potential inundation is often limited by the lack of available data as well as model complexity. We present in this paper a new approach for rapid inundation mapping, MHYST, which is well adapted for data-scarce areas; it is based on hydraulic geometry concepts for channels, and on DEM data for floodplains. Its originality lies in the fact that it does not work at the cross section scale but computes effective geometrical properties to describe the reach scale. Combining reach-scale geometrical properties with 1-D steady-state flow equations, MHYST computes a topographically coherent relation between the Height Above Nearest Drainage and streamflow. This relation can then be used on a past or future event and produce inundation maps. The MHYST approach is tested here on an extreme flood event that occurred in France in May–June 2016. The results indicate that it has a tendency to slightly underestimate inundation extents, although efficiency criteria values are clearly encouraging. The spatial distribution of model performance is discussed and it shows that the model can perform very well on most reaches, but has difficulties modelling the more complex, urbanised reaches. MHYST should not be seen as a rival to detailed inundation studies, but as a first approximation able to rapidly provide inundation maps in data-scarce areas.
Complex interplay between stress perturbations and viscoelastic relaxation in a two-asperity fault model
Authors: Lorenzano Emanuele , Dragoni Michele
Published: March 2018

Abstract. We consider a plane fault with two asperities embedded in a shear zone,
subject to a uniform strain rate owing to tectonic loading. After an
earthquake, the static stress field is relaxed by viscoelastic deformation in
the asthenosphere. We treat the fault as a discrete dynamical system with 3
degrees of freedom: the slip deficits of the asperities and the variation of
their difference due to viscoelastic deformation. The evolution of the fault
is described in terms of inter-seismic intervals and slip episodes, which may
involve the slip of a single asperity or both. We consider the effect of
stress transfers connected to earthquakes produced by neighbouring faults.
The perturbation alters the slip deficits of both asperities and the stress
redistribution on the fault associated with viscoelastic relaxation. The
interplay between the stress perturbation and the viscoelastic relaxation
significantly complicates the evolution of the fault and its seismic
activity. We show that the presence of viscoelastic relaxation prevents any
simple correlation between the change of Coulomb stresses on the asperities
and the anticipation or delay of their failures. As an application, we study
the effects of the 1999 Hector Mine, California, earthquake on the
post-seismic evolution of the fault that generated the 1992 Landers,
California, earthquake, which we model as a two-mode event associated with
the consecutive failure of two asperities.
ABB-ABC-ABE-ABM Approach for Implementation in the Economic Entities from Energy Industry
Authors: Topor Dan Ioan , Capusneanu Sorinel , Constantin Dana Maria , Barbu Cristian Marian , Rakos Ileana Sorina
Published: March 2018

The purpose of this article lies in demonstrating the effectiveness of four connection methods ABB-ABC-ABE-ABM conducive to successful implementation and improving the performance of an economic entity. The objectives of this study are focused on: (1) the application of ABB-ABC-ABE-ABM within an economic entity within the energetic industry and (2) highlighting performances, including environmental performance. In the framework of this article the contributions are brought by the mix of methods on the national and international level, namely the modalities and stages of their specific within an economic entity. Environmental components are addressed within the mix of economic entity methods used, their benefits and limitations. Based on case study prepared by the authors, the results of applied methods mix to improve environmental performance within the surveyed entity are presented. The article ends with the conclusions of the authors related to the efficiency of the use of the ABB-ABM-ABC-ABE for improving performance, including environmental performance within the surveyed entity.
Humanizing the Classroom: Praxis of Full Day School System in Indonesia
Authors: Suyatno Suyatno , Wantini Wantini
Published: March 2018

The full day school program is a new model in the education management system in Indonesia. This phenomenon is interesting because there is a paradox in it. Education in Indonesia is often criticized for the learning which is too heavy, but the full day school program gets a positive response from the community although it has longer school hours. This research aims to answer the questions; 1) How is a full day school praxis program in Indonesia? Second, how is the implementation of humanizing the classroom learning program in schools that implement the full day school program? This research is a qualitative research with locus at Islam Terpadu Salsabila Elementary School (SDIT Salsabila), Yogyakarta. Research subject is determined by purposive sampling. Method of data collections are: 1) participant observation, 2) in-depth interview, 3) questionnaire, and 4) document analysis. Data analysis technique is inductive-qualitative. The results are; First, the full day school program in Indonesia is growing as a result of the increasing number of busy working parents. They do not have the opportunity to accompany their children at home because they are busy working from morning to evening. The full day school program is an educative solution for them. Secondly, humanizing the classroom is implemented through students’ active involvement in the classroom and the learning process is democratic and fun. This approach is a solution so that students do not feel boredom in learning although they spent their time throughout the day at school.
Defining a New 21st Century Skill-Computational Thinking: Concepts and Trends
Authors: Haseski Halil Ibrahim , Ilic Ulas , Tugtekin Ufuk
Published: March 2018

Computational Thinking is a skill that guides the 21th century individual in the problems experienced during daily life and it has an ever-increasing significance. Multifarious definitions were attempted to explain the concept of Computational Thinking. However, it was determined that there was no consensus on this matter in the literature and several different concepts were mentioned in the definitions found in the literature. It was considered that this fact made it difficult to understand the concept of Computational Thinking. To establish a more comprehensive approach, the present study aimed to identify the concepts that are included in the Computational Thinking definitions that were presented in previous studies. It also aimed to reveal trends in the identified concepts throughout the years. As a result of the search, a total of 59 definitions were identified and a content analysis was conducted on these definitions. Analysis results demonstrated that Computational Thinking was defined based on several concepts such as problem solving, technology, thinking, individual and social qualities. Furthermore, it was determined that statements on thinking were prominent before 2006, and today, emphasis on problem solving and technology became more significant. It was considered that the present study would contribute to a better understanding of the Computational Thinking concept. At the end of the study, certain suggestions were presented for further research.
The Influence of Choice Theory Anger Management Program (CTAMP) on the Ability of Prospective Psychological Counselors for Anger Management
Authors: Gundogdu Rezzan
Published: March 2018

This research is a quasi-experimental study with pretest-posttest-fallow up test and experiment-control group to investigate the influence of Choice Theory-based Anger Management Psychoeducation Program (CTAMP) on the ability of students of Department of Psychological Counseling and Guidance (PCG) for anger management. The Trait Anger-Anger Style Scale was used for the dependent variable. 40 students were identified as eligible to participate in the study based on the scores from subscales of STAS. Then a total of 18 volunteer students (14 females and 5 males) were identified that had time to participate in activities. The control group included 19 students (14 females, 5 males). The CTAMP was administrated to the experimental group for twelve weeks, and no procedures were performed for the control group. Then, reminder sessions were held for 3 more weeks for the control group and the final follow-up measurement was taken. The data was analyzed by SPSS 18 packet program. The t-test was performed to find the differences between the follow up pretest–follow up posttest scores in the experimental and control groups, and ANOVA was carried out to find the within-group differences for repeated measurements. At the end of CTAMP that lasted 12 weeks, it is observed that the trait anger-anger, anger-in and anger-out scores for the experimental group were reduced from the pretest to posttest, but the anger control scores were increased. At the end of follow-up sessions, the variance in the scores was similar.
The Challenges of Using the Differentiated Instruction Strategy: A Case Study in the General Education Stages in Saudi Arabia
Authors: Aldossari Ali Tared
Published: March 2018

The study identifies the most important challenges facing general education male and female teachers in applying the differentiated instruction strategy in different stages of education in the Eastern Province in the Kingdom of Saudi Arabia. To achieve this, the researcher designed a questionnaire consisting of 47 paragraphs on five axes. It was distributed to 275 male and female teachers in Dammam city, after having verified its validity and stability,The results indicate that the degree of the challenge of using the differentiated instruction strategy was medium overall. The challenges related to students were ranked first, followed by challenges related to the school environment, then the nature of the differentiated instruction, challenges related to teachers, and, finally, challenges related to study courses.However, the results were not statistically significant for the variable of the educational stage (primary, intermediate, and secondary), although there were significant differences for the gender variable in favour of males.The study recommends creating a school environment that supports the use of a differentiated instruction strategy and holding workshops for teachers to train them in differentiated instruction activities.
Parametric Design of Aircraft Wing with Curved Leading Edge
Authors: BENAOULI Abdelkader , KACHEL Stanisław
Published: March 2018

In order to ease modelling procedures, eliminate repetitive effort and save time, modern CAD tools offer the ability to automate tasks via a programming language. Moreover, when the design is an iterative process, the automation permits updating the design variables to generate a new model at each iteration. Based on UG/OPEN GRIP functionalities, this paper aims at developing a parametric model of
a curved leading edge aircraft wing. The model is built by executing a GRIP program in which wing parameter values can be assigned via a dialog box.
Identify Lead Plumbing Sources to Protect Public Health
Authors: Lytle Darren A. , Schock Michael R. , Triantafyllidou Simoni
Published: March 2018

Various drinking water sampling approaches can be taken to assess the presence of lead in drinking water. Water utilities should consider using diagnostic sampling to help identify lead sources.
Twenty steps towards an adequate inferential interpretation of p-values
Authors: Hirschauer Norbert , Grüner Sven , Mußhoff Oliver , Becker Claudia
Published: March 2018

We suggest twenty immediately actionable steps to reduce widespread inferential errors related to “statistical significance testing.” Our propositions refer first to the theoretical preconditions for using p-values. They furthermore include wording guidelines as well as structural and operative advice of how to present results, especially in multiple regression analysis. Our propositions aim at fostering the logical consistency of inferential arguments by avoiding false categorical reasoning. They are not aimed at dispensing with p-values or completely replacing frequentist approaches by Bayesian statistics.
Crystal structure of exo‐rhamnogalacturonan lyase from Penicillium chrysogenum as a member of polysaccharide lyase family 26
Authors: Kunishige Yuika , Iwai Marin , Nakazawa Masami , Ueda Mitsuhiro , Tada Toshiji , Nishimura Shigenori , Sakamoto Tatsuji
Published: March 2018

Exo‐rhamnogalacturonan lyase from Penicillium chrysogenum 31B (PcRGLX) was recently classified as a member of polysaccharide lyase (PL) family 26 along with hypothetical proteins derived from various organisms. In this study, we determined the crystal structure of PcRGLX as the first structure of a member of this family. Based on the substrate‐binding orientation and substrate specificity, PcRGLX is an exo‐type PL that cleaves rhamnogalacturonan from the reducing end. Analysis of PcRGLX‐complex structures with reaction products indicate that the active site possesses an L‐shaped cleft that can accommodate galactosyl side chains, suggesting side‐chain‐bypassing activity in PcRGLX. Furthermore, we determined the residues critical for catalysis by analyzing the enzyme activities of inactive variants.
Mechanisms Controlling Global Mean Sea Surface Temperature Determined From a State Estimate
Authors: Ponte R. M. , Piecuch C. G.
Published: March 2018

Global mean sea surface temperature (
) is a variable of primary interest in studies of climate variability and change. The temporal evolution of
can be influenced by surface heat fluxes (
) and by diffusion (
) and advection (
) processes internal to the ocean, but quantifying the contribution of these different factors from data alone is prone to substantial uncertainties. Here we derive a closed
budget for the period 1993–2015 based on a global ocean state estimate, which is an exact solution of a general circulation model constrained to most extant ocean observations through advanced optimization methods. The estimated average temperature of the top (10‐m thick) level in the model, taken to represent
, shows relatively small variability at most time scales compared to
,
, or
, reflecting the tendency for largely balancing effects from all the latter terms. The seasonal cycle in
is mostly determined by small imbalances between
and
, with negligible contributions from
. While
seems to simply damp
at the annual period, a different dynamical role for
at semiannual period is suggested by it being larger than
. At periods longer than annual,
contributes importantly to
variability, pointing to the direct influence of the variable ocean circulation on
and mean surface climate.
Effect of the Lateral Exospheric Transport on the Horizontal Hydrogen Distribution Near the Exobase of Mars
Authors: Chaufray J.‐Y. , Yelle R. V. , Gonzalez‐Galindo F. , Forget F. , Lopez‐Valverde M. , Leblanc F. , Modolo R.
Published: March 2018

We simulate the hydrogen density near the exobase of Mars, using the 3‐D Martian Global Circulation Model of Laboratoire de Météorologie Dynamique, coupled to an exospheric ballistic model to compute the downward ballistic flux. The simulated hydrogen distribution near the exobase obtained at two different seasons—Ls = 180° and Ls = 270°—is close to Zero Net Ballistic Flux equilibrium. In other words, the hydrogen density near the exobase adjusts to have a balance between the local upward ballistic and the downward ballistic flux due to a short lateral migration time in the exosphere compared to the vertical diffusion time. This equilibrium leads to a hydrogen density n near the exobase directly controlled by the exospheric temperature T by the relation nT5/2 = constant. This relation could be used to extend 1‐D hydrogen exospheric model of Mars used to derive the hydrogen density and escape flux at Mars from Lyman‐α observations to 3‐D model based on observed or modeled exospheric temperature near the exobase, without increasing the number of free parameters.
Did the 2008 Mw 7.9 Wenchuan Earthquake Trigger the Occurrence of the 2017 Mw 6.5 Jiuzhaigou Earthquake in Sichuan, China?
Authors: Jia Ke , Zhou Shiyong , Zhuang Jiancang , Jiang Changsheng , Guo Yicun , Gao Zhaohui , Gao Shesheng
Published: March 2018

The 2017 Mw 6.5 Jiuzhaigou earthquake occurred at the southeastern boundary of the Bayankala block in Tibetan Plateau. Here we investigate the spatial and temporal seismicity rate changes in the Jiuzhaigou region using the finite‐source epidemic‐type aftershock sequence model and stochastic declustering method. The background probabilities of all events are obtained, and the cumulative background seismicity is extracted and fitted by a linear function. Following from this, we argue that there was a decrease of background seismicity in Jiuzhaigou region immediately after the occurrence of the 2008 Mw 7.9 Wenchuan earthquake. On the other hand, we also calculate the static and viscoelastic stress changes in the area around the hypocenter of the Jiuzhaigou earthquake induced by the Wenchuan earthquake. Although opposite results are resolved by previous studies, we infer a negative Coulomb failure stress change under reasonable assumptions of parameters for this case. Combining these two observed empirical relationships, we conclude that the 2017 Jiuzhaigou earthquake is delayed by the Wenchuan earthquake and the former event possibly results from the southeastward movement of the Bayankala block, which in turn arises from the collision of Indian‐Australian Plate and the Eurasian Plate. These findings indicate that Bayankala block and its adjacent tectonic faults are still in the highly active seismic period that started in the 1990s.
Regional Hydroclimatic Variability Due To Contemporary Deforestation in Southern Amazonia and Associated Boundary Layer Characteristics
Authors: Khanna Jaya , Medvigy David , Fisch Gilberto , de Araújo Tiburtino Neves Theomar Trindade
Published: March 2018

Amazonian deforestation causes systematic changes in regional dry season precipitation. Some of these changes at contemporary large scales (a few hundreds of kilometers) of deforestation have been associated with a “dynamical mesoscale circulation,” induced by the replacement of rough forest with smooth pasture. In terms of decadal averages, this dynamical mechanism yields increased precipitation in downwind regions and decreased precipitation in upwind regions of deforested areas. Daily, seasonal, and interannual variations in this phenomenon may exist but have not yet been identified or explained. This study uses observations and numerical simulations to develop relationships between the dynamical mechanism and the local‐ and continental‐scale atmospheric conditions across a range of time scales. It is found that the strength of the dynamical mechanism is primarily controlled by the regional‐scale thermal and dynamical conditions of the boundary layer and not by the continental‐ and global‐scale atmospheric state. Lifting condensation level and wind speed within the boundary layer have large and positive correlations with the strength of the dynamical mechanism. The strength of these relationships depends on time scale and is strongest over the seasonal cycle. Overall, the dynamical mechanism is found to be strongest during times when the atmosphere is relatively stable. Hence, for contemporary large scales of deforestation this phenomenon is found to be the prevalent convective triggering mechanism during the dry and parts of transition seasons (especially during the dry‐to‐wet transition), significantly affecting the hydroclimate during this period.
Regional to Global Biogenic Isoprene Emission Responses to Changes in Vegetation From 2000 to 2015
Authors: Chen W. H. , Guenther A. B. , Wang X. M. , Chen Y. H. , Gu D. S. , Chang M. , Zhou S. Z. , Wu L. L. , Zhang Y. Q.
Published: March 2018

Isoprene, a dominant biogenic volatile organic compound that is mainly emitted by trees, has a significant impact on the atmospheric chemistry. Regional to global changes in biogenic isoprene emission associated with vegetation variations between 2000 and 2015 were estimated using the MEGAN model with satellite land cover data for inputs in this study. The satellite data estimates of land cover changes were compared to results from previous investigators that have either conducted regional studies or have used lower resolution land cover data. The analysis indicates that tree coverage increases of >5% occurred in 13% of locations including in central China and Europe. In contrast, a decrease of >5% was observed in about 5% of locations, especially in tropical regions. The trends in global tree coverage from 2000 to 2015 resulted in a global isoprene emission decrease of only 1.5%, but there were significant regional variations. Obvious decreases in tree coverage in some tropical areas (e.g., Amazon Basin, Western Africa, Southeast Asia) resulted in a ~10% reduction of regional isoprene emission due to agricultural expansion. Distinct increments of isoprene emission (5–10%) were mainly found in Northeast China and India and were associated with afforestation efforts. Deforestation and afforestation associated with managed plantations does not only affect the total forest coverage but also impacts average isoprene emission capacity, which can result in accelerated isoprene emission variations. Consequently, isoprene variation assessments are needed that not only account for changes in vegetation fractions but also consider the changes in plant species compositions of forests and other landscapes.
Parameterization of Rocket Dust Storms on Mars in the LMD Martian GCM: Modeling Details and Validation
Authors: Wang Chao , Forget François , Bertrand Tanguy , Spiga Aymeric , Millour Ehouarn , Navarro Thomas
Published: March 2018

The origin of the detached dust layers observed by the Mars Climate Sounder aboard the Mars Reconnaissance Orbiter is still debated. Spiga et al. (2013, https://doi.org/10.1002/jgre.20046) revealed that deep mesoscale convective “rocket dust storms” are likely to play an important role in forming these dust layers. To investigate how the detached dust layers are generated by this mesoscale phenomenon and subsequently evolve at larger scales, a parameterization of rocket dust storms to represent the mesoscale dust convection is designed and included into the Laboratoire de Météorologie Dynamique (LMD) Martian Global Climate Model (GCM). The new parameterization allows dust particles in the GCM to be transported to higher altitudes than in traditional GCMs. Combined with the horizontal transport by large‐scale winds, the dust particles spread out and form detached dust layers. During the Martian dusty seasons, the LMD GCM with the new parameterization is able to form detached dust layers. The formation, evolution, and decay of the simulated dust layers are largely in agreement with the Mars Climate Sounder observations. This suggests that mesoscale rocket dust storms are among the key factors to explain the observed detached dust layers on Mars. However, the detached dust layers remain absent in the GCM during the clear seasons, even with the new parameterization. This implies that other relevant atmospheric processes, operating when no dust storms are occurring, are needed to explain the Martian detached dust layers. More observations of local dust storms could improve the ad hoc aspects of this parameterization, such as the trigger and timing of dust injection.
Venus Resurfacing Constrained by Geoid and Topography
Authors: King Scott D.
Published: March 2018

The primary explanations for the young crater age of the surface of Venus are progressive volcanic resurfacing and a period of mobile‐lid tectonics. The role of initial conditions, mantle potential temperature, and core potential temperature on Venus surface mobility are explored using 3‐D spherical mantle convection calculations with a lithospheric yield stress that allows the fluid to adopt either a stagnant or mobile lid. The small offset between the center of mass and center of figure (CM‐CF) of Venus is reproduced in calculations that never undergo a period of mobile‐lid convection. The CM‐CF offset has never been used in the evaluation of geodynamic models for Venus. The mobile‐lid calculations have a CM‐CF offset that is four times the observed offset, and the offset increases significantly at the onset of a mobile lid/resurfacing event. Furthermore, the rapid increase in core mantle boundary heat flow that occurs as the cold lithospheric material interacts with the core mantle boundary during a mobile‐lid event is sufficient to power a core dynamo, even in the absence of inner core solidification. The core mantle boundary heat flow decays over 1 Gyr after the cessation of mobile‐lid tectonics. The heat flow never reaches a level that would power a thermally driven dynamo in calculations that do not undergo mobile‐lid convection. The calculations indicate that Venus young surface age is not the result of a mobile‐lid resurfacing event while progressive resurfacing is consistent with the observations.
Underutilized Spaceborne GPS Observations for Space Weather Monitoring
Authors: Zakharenkova Irina , Cherniak Iurii
Published: March 2018

Many of currently operated low Earth orbit satellites, in particular Earth observing meteorological missions, are equipped with dual‐frequency Global Positioning System (GPS) receivers with a zenith‐looking antenna for tasks of precise orbit determination and timing. The already existed databases with accumulated raw GPS measurements, as a by‐product of satellite missions, can arouse specific interest for ionospheric and space weather community too. We demonstrate potential possibilities and advantages of involving underutilized spaceborne GPS measurements for Space Weather activity monitoring by specification of storm‐induced ionospheric plasma density irregularities at different altitudinal domain of the topside ionosphere. We have analyzed a dynamical response of the high‐latitude topside ionosphere to the intense geomagnetic storm of 19–21 December 2015 using up‐looking GPS measurements on board Swarm and Meteorological Operational satellite (MetOp) missions, flying at altitudes of ~500 km and ~835 km, respectively. For the first time, GPS observations on board the meteorological mission MetOp were used to reveal an occurrence of plasma irregularities at altitudes above 835 km. Our results demonstrate that during strong geomagnetic storms the intense plasma density irregularities can occur in the topside ionosphere near ~500 km altitude and can be still persisted above 835 km. Joint analysis of the Super Dual Auroral Radar Network global convection patterns, ground‐based GPS total electron content (TEC) observations, and MetOp‐derived topside TEC observations confirmed that plasma irregularities above ~835 km coincided with the plasmaspheric/magnetospheric part of the storm‐enhanced density and the polar tongue of ionization structures, which is the first direct observation of the storm‐enhanced density/tongue of ionization structure in the plasmaspheric TEC.
Riverbed Hydrologic Exchange Dynamics in a Large Regulated River Reach
Authors: Zhou Tian , Bao Jie , Huang Maoyi , Hou Zhangshuan , Arntzen Evan , Song Xuehang , Harding Samuel F. , Titzler P. Scott , Ren Huiying , Murray Christopher J. , Perkins William A. , Chen Xingyuan , Stegen James C. , Hammond Glenn E. , Thorne Paul D. , Zachara John M.
Published: March 2018

Hydrologic exchange flux (HEF) is an important hydrologic component in river corridors that includes both bidirectional (hyporheic) and unidirectional (gaining/losing) surface water‐groundwater exchanges. Quantifying HEF rates in a large regulated river is difficult due to the large spatial domains, complexity of geomorphologic features and subsurface properties, and the great stage variations created by dam operations at multiple time scales. In this study, we developed a method that combined numerical modeling and field measurements for estimating HEF rates across the riverbed in a 7 km long reach of the highly regulated Columbia River. A high‐resolution computational fluid dynamics (CFD) modeling framework was developed and validated by field measurements and other modeling results to characterize the HEF dynamics across the riverbed. We found that about 85% of the time from 2008 to 2014 the river was losing water with an annual average net HEF rates across the riverbed (Qz) of −2.3 m3 s−1 (negative indicating downwelling). June was the only month that the river gained water, with monthly averaged Qz of 0.8 m3 s−1. We also found that the daily dam operations increased the hourly gross gaining and losing rate over an average year of 8% and 2%, respectively. By investigating the HEF feedbacks at various time scales, we suggest that the dam operations could reduce the HEF at seasonal time scale by decreasing the seasonal flow variations, while also enhance the HEF at subdaily time scale by generating high‐frequency discharge variations. These changes could generate significant impacts on biogeochemical processes in the hyporheic zone.
Normal Faulting in the 1923 Berdún Earthquake and Postorogenic Extension in the Pyrenees
Authors: Stich Daniel , Martín Rosa , Batlló Josep , Macià Ramón , Mancilla Flor de Lis , Morales Jose
Published: March 2018

The 10 July 1923 earthquake near Berdún (Spain) is the largest instrumentally recorded event in the Pyrenees. We recover old analog seismograms and use 20 hand‐digitized waveforms for regional moment tensor inversion. We estimate moment magnitude Mw 5.4, centroid depth of 8 km, and a pure normal faulting source with strike parallel to the mountain chain (N292°E), dip of 66° and rake of −88°. The new mechanism fits into the general predominance of normal faulting in the Pyrenees and extension inferred from Global Positioning System data. The unique location of the 1923 earthquake, near the south Pyrenean thrust front, shows that the extensional regime is not confined to the axial zone where high topography and the crustal root are located. Together with seismicity near the northern mountain front, this indicates that gravitational potential energy in the western Pyrenees is not extracted locally but induces a wide distribution of postorogenic deformation.
Rupture Dynamics of Heterogeneous Frictional Interfaces
Authors: Bayart E. , Svetlizky I. , Fineberg J.
Published: March 2018

The onset of sliding motion is conditional on the propagation of rupture fronts that detach the contacting asperities forming a frictional interface. These ruptures, when propagating over a fault surface, are the most common mechanism for an earthquake. Experimentally, the transition from static to sliding friction takes place when a rupture traverses the entire interface. But ruptures can also arrest before reaching the end of the interface. The determination of the mechanisms responsible for rupture arrest is of particular interest for understanding an earthquake's magnitude selection. Propagating ruptures have been shown to be true shear cracks, driven by singular fields at their tip, and fracture mechanics have been successfully used to describe rupture arrest along homogeneous frictional interfaces. Performing high temporal resolution measurements of the real contact area and strain fields, we demonstrate that the same framework provides an excellent quantitative description of rupture arrest along interfaces with heterogeneous fracture properties and complex stress distributions at a macroscopic scale. This work unravels the different mechanisms responsible for rupture arrest along model laboratory faults. This fracture‐based paradigm opens a window to a wide range of possible consequences for frictional behavior along any two contacting bodies; from the centimeter scale to the scale of natural faults.
Brain‐computer interfaces for post‐stroke motor rehabilitation: a meta‐analysis
Authors: Cervera María A. , Soekadar Surjo R. , Ushiba Junichi , Millán José del R. , Liu Meigen , Birbaumer Niels , Garipelli Gangadhar
Published: March 2018

Brain‐computer interfaces (BCIs) can provide sensory feedback of ongoing brain oscillations, enabling stroke survivors to modulate their sensorimotor rhythms purposefully. A number of recent clinical studies indicate that repeated use of such BCIs might trigger neurological recovery and hence improvement in motor function. Here, we provide a first meta‐analysis evaluating the clinical effectiveness of BCI‐based post‐stroke motor rehabilitation. Trials were identified using MEDLINE, CENTRAL, PEDro and by inspection of references in several review articles. We selected randomized controlled trials that used BCIs for post‐stroke motor rehabilitation and provided motor impairment scores before and after the intervention. A random‐effects inverse variance method was used to calculate the summary effect size. We initially identified 524 articles and, after removing duplicates, we screened titles and abstracts of 473 articles. We found 26 articles corresponding to BCI clinical trials, of these, there were nine studies that involved a total of 235 post‐stroke survivors that fulfilled the inclusion criterion (randomized controlled trials that examined motor performance as an outcome measure) for the meta‐analysis. Motor improvements, mostly quantified by the upper limb Fugl‐Meyer Assessment (FMA‐UE), exceeded the minimal clinically important difference (MCID=5.25) in six BCI studies, while such improvement was reached only in three control groups. Overall, the BCI training was associated with a standardized mean difference of 0.79 (95% CI: 0.37 to 1.20) in FMA‐UE compared to control conditions, which is in the range of medium to large summary effect size. In addition, several studies indicated BCI‐induced functional and structural neuroplasticity at a subclinical level. This suggests that BCI technology could be an effective intervention for post‐stroke upper limb rehabilitation. However, more studies with larger sample size are required to increase the reliability of these results.
Novel Ceramic‐Based Material for the Applications of Molded Interconnect Devices (3D‐MID) Based on Laser Direct Structuring
Authors: Bachy Bassim , Süß‐Wolf Robert , Wang Li , Fu Zongwen , Travitzky Nahum , Greil Peter , Franke Jörg
Published: March 2018

Molded interconnect devices (MID) based on laser direct structuring LPKF‐LDS® technology are widely used in the realm of electronics. Nowaday, design and development of new materials with improved properties for 3D‐MID are in focus. In this work, novel materials based on alumina ceramic with copper oxide additives are developed for this technology. The effect of the sintering temperature and the doping amount of copper oxide on the metallization quality is investigated. Furthermore, the influence of laser process parameters (e.g., laser power, velocity’, and frequency) on process output namely groove dimensions, groove profile, characteristics of structured area, and quality of the final 3D‐MID products are discussed. The novel ceramic materials show high flexibility to realize very fine structures. Moreover, the laser‐structured and metallized area shows a free edge lap with good quality. After metallization high accuracy with copper line/pitch of 16 μm/20 μm is achieved.
Coding Cell Micropatterns Through Peptide Inkjet Printing for Arbitrary Biomineralized Architectures
Authors: Guo Jin , Ling Shengjie , Li Wenyi , Chen Ying , Li Chunmei , Omenetto Fiorenzo G. , Kaplan David L.
Published: March 2018

Well‐designed micropatterns present in native tissues and organs involve changes in extracellular matrix compositions, cell types and mechanical properties to reflect complex biological functions. However, the design and fabrication of these micropatterns in vitro to meet task‐specific biomedical applications remains a challenge. A de novo design strategy to code and synthesize functional micropatterns is presented to engineer cell alignment through the integration of aqueous‐peptide inkjet printing and site‐specific biomineralization. The inkjet printing provides direct writing of macroscopic biosilica selective peptide‐R5 patterns with micrometer‐scale resolution on the surface of a biopolymer (silk) hydrogel. This is combined with in situ biomineralization of the R5 peptide for site‐specific growth of silica nanoparticles on the micropatterns, avoiding the use of harsh chemicals or complex processing. The functional micropatterned systems are used to align human mesenchymal stem cells and bovine serum albumin. This combination of peptide printing and site‐specific biomineralization provides a new route for developing cost‐effective micropatterns, with implications for broader materials designs.