bluuebunny/crossref_metadata_2025 huggingface dataset:
Insights into characteristics, sources and evolution of submicron aerosols during harvest seasons in Yangtze River Delta (YRD) region, China
Authors: Zhang Y. J. , Tang L. L. , Wang Z. , Yu H. X. , Sun Y. L. , Liu D. , Qin W. , Zhang H. L. , Zhou H. C.
Published: April 2014

Abstract. Atmospheric submicron particulate matter (PM1) is one of the most significant pollution components in China. Despite its current popularity in the studies of aerosol chemistry, the characteristics, sources and evolution of atmospheric PM1 species in the East China are still poorly understood. Particular situations are the two harvest seasons, namely summer wheat harvest and autumn rice harvest. An Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was deployed for online continuous monitoring of PM1 components during summer and autumn harvest seasons in urban Nanjing situated in the Yangtze River Delta (YRD) region of China. Results show that organic aerosol (OA) was the most abundant PM1 component, accounting for 39% and 41% of the total mass during the summer and autumn harvest periods, respectively. Positive matrix factorization (PMF) analysis resolved three OA components, i.e., hydrocarbon-like OA (HOA), biomass burning OA (BBOA), and oxygenated OA (OOA), which on average accounted for 19% (30%), 17% (18%), and 64% (52%) of the total OA mass concentrations during the summer (autumn) harvest respectively. The BBOA mass fraction increases with an increase of high PM1 mass loadings (PM1 > 100 μg m−3), implying that BBOA plays a dominate role in high PM pollution during the harvest seasons. The mass concentrations of BBOA correlate well with the mass concentration of water-soluble potassium (K+), indicating that the atmospheric K+ is a good tracer for both wheat and rice straw burning during the harvest seasons. The BBOA mass concentrations for the summer and autumn harvest can be estimated as BBOA = 36.7 × (m/z 60–0.26% × OA) and = 41.4 × (m/z 60–0.26% × OA), respectively, m/z 60 as an identified marker for levoglucosan-like species. The OA mass decreases with the aging of BB plumes, implying that the fresh BB plumes contribute to atmospheric OA burden significantly. Combination of back-trajectory analysis with local wind indicates that the heavy pollution during the harvest seasons in the YRD region was found to be associated with transport processes and local source emissions.
Characteristics of cloud liquid water path from SEVIRI onboard the Meteosat Second Generation 2 satellite for several cloud types
Authors: Kniffka A. , Stengel M. , Lockhoff M. , Bennartz R. , Hollmann R.
Published: April 2014

Abstract. In this study the temporal and spatial characteristics of the liquid water path (LWP) of low, middle and high level clouds are analysed using space-based observations from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument onboard the Meteosat Second Generation 2 (MSG 2) satellite. Both geophysical quantities are part of the CLAAS (CLoud property dAtAset using SEVIRI) data set and are generated by EUMETSAT's Satellite Application Facility on Climate Monitoring (CM SAF). In this article we focus on the statistical properties of LWP, retrieved during daylight conditions, associated with individual cloud types. We analysed the intrinsic variability of LWP, that is, the variability in only cloudy regions and the variations driven by cloud amount. The relative amplitude of the intrinsic diurnal cycle exceeded the cloud amount driven amplitude in our analysed cases. Our results reveal that each cloud type possesses a characteristic intrinsic LWP distribution. These frequency distributions are constant with time in the entire SEVIRI field of view, but vary for smaller regions like Central Europe. Generally the average LWP is higher over land than over sea; in the case of low clouds this amounts to 15–27% in 2009. The variance of the frequency distributions is enhanced as well. Also, the average diurnal cycle of LWP is related to cloud type with the most pronounced relative diurnal variations being detected for low and middle level clouds. Maps of the relative amplitude and the local time of maximum LWP show the variation throughout the SEVIRI field of view.
Volcanic ash infrared signature: porous non-spherical ash particle shapes compared to homogeneous spherical ash particles
Authors: Kylling A. , Kahnert M. , Lindqvist H. , Nousiainen T.
Published: April 2014

Abstract. The reverse absorption technique is often used to detect volcanic ash clouds from thermal infrared satellite measurements. From these measurements effective particle radius and mass loading may be estimated using radiative transfer modelling. The radiative transfer modelling usually assumes that the ash particles are spherical. We calculated thermal infrared optical properties of highly irregular and porous ash particles and compared these with mass- and volume-equivalent spherical models. Furthermore, brightness temperatures pertinent to satellite observing geometry were calculated for the different ash particle shapes. Non-spherical shapes and volume-equivalent spheres were found to produce a detectable ash signal for larger particle sizes than mass-equivalent spheres. The assumption of mass-equivalent spheres for ash mass loading estimates was found to underestimate mass loading compared to morphologically complex inhomogeneous ash particles. The underestimate increases with the mass loading. For an ash cloud recorded during the Eyjafjallajökull 2010 eruption, the mass-equivalent spheres underestimate the total mass of the ash cloud by approximately 30% compared to the morphologically complex inhomogeneous particles.
A neural network approach for the simultaneous retrieval of volcanic ash parameters and SO2 using MODIS data
Authors: Piscini A. , Picchiani M. , Chini M. , Corradini S. , Merucci L. , Del Frate F. , Stramondo S.
Published: April 2014

Abstract. In this work neural networks have been used for the retrieval of volcanic ash and SO2 parameters based on Moderate Resolution Imaging Spectroradiometer (MODIS) multispectral measurements. Different neural networks were built for each parameter to be retrieved, experimenting different topologies and evaluating their performances. As test case the May 2010 Eyjafjallajokull eruption has been considered. A set of six MODIS images have been used for the training and validation phases. In order to estimate of the parameters associated with volcanic eruption such as ash mass, effective radius, aerosol optical depth and sulphur dioxide columnar abundance, the neural networks have been trained by using the retrievals obtained from well known algorithms based on simulated radiances at the top of the atmosphere estimated from radiative transfer models. Three neural network's topologies with a different number of inputs have been compared: (a) only three MODIS TIR channels, (b) all multispectral MODIS channels and (c) only the channels that were selected by a pruning procedure applied to all MODIS channels. Results show that the neural network approach is able to reproduce very well the results obtained from the standard algorithms for all retrieved parameters, showing a root mean square error (RMSE) computed from the validation sets below the target data standard deviation (STD). In particular the network built considering all the MODIS channels gives a better performance in terms of specialization, mainly on images close in time to the training ones, while, as expected, the networks with less inputs reveals a better generalization performance when applied to independent datasets. In order to increase the network generalization capability, a pruning algorithm has been also implemented. Such a procedure permits to operate a features selection, extracting only the most significant MODIS channels from images. The results of pruning revealed that obtained inputs, for all the retrieved parameters, correspond to the TIR channels sensitive to ash, plus some other channels in the visible and mid-infrared spectral ranges. The artificial neural network approach proved to be effective in addressing the inversion problem for the estimation of volcanic ash and SO2 cloud parameters, providing fast and reliable retrievals, which are important requirements during the volcanic crisis.
Foraminiferal species responses to in situ, experimentally induced anoxia in the Adriatic Sea
Authors: Langlet D. , Baal C. , Geslin E. , Metzger E. , Zuschin M. , Riedel B. , Risgaard-Petersen N. , Stachowitsch M. , Jorissen F. J.
Published: April 2014

Abstract. Anoxia was successfully induced in four benthic chambers installed at 24 m depth in the northern Adriatic Sea for periods varying from 9 days to 10 months. During the 10-month period, species richness significantly decreased. Although no significant change in Shannon diversity and evenness was observed, the composition of the foraminiferal assemblages changed with time. This change is due to interspecific differences in tolerance to anoxia. Reophax nanus, Textularia agglutinans and Quinqueloculina stelligera all showed a significant decrease with time, strongly suggesting they are sensitive to anoxia. Conversely, Eggerella scabra, Bulimina marginata, Lagenammina atlantica, Hopkinsina pacifica and Bolivina pseudoplicata appeared to be resistant to the experimental conditions. Quinqueloculina seminula was apparently sensitive to anoxia but showed a clear standing stock increase during the first month of the experiment, which we interpret as an opportunistic response to increasing organic matter availability due to the degradation of the dead macrofaunal organisms. None of the anoxia-sensitive species is able to accumulate intracellular nitrates. Nitrate accumulation could be shown for some tested specimens of the dominant anoxia-tolerant species E. scabra and B. marginata. However, tests on the denitrification capacity of these taxa yielded negative results, suggesting that their resistance to long-term anoxia is not due to their ability to denitrify.
Two perspectives on the coupled carbon, water, and energy exchange in the planetary boundary layer
Authors: Combe M. , Vilà-Guerau de Arellano J. , Ouwersloot H. G. , Jacobs C. M. J. , Peters W.
Published: April 2014

Abstract. Understanding the interactions between the land surface and the atmosphere is key to model boundary-layer meteorology and cloud formation, as well as carbon cycling and crop yield. In this study we explore these interactions in the exchange of water, heat, and CO2 in a cropland–atmosphere system at the diurnal and local scale. We thereto couple an atmospheric mixed-layer model (MXL) to two land-surface schemes, developed from two different perspectives: while one land-surface scheme (A-gs) simulates vegetation from an atmospheric point of view, the other (GECROS) simulates vegetation from a carbon-storage point of view. We calculate surface fluxes of heat, moisture and carbon, as well as the resulting atmospheric state and boundary-layer dynamics, over a maize field in the Netherlands, for a day on which we have a rich set of observations available. Particular emphasis is placed on understanding the role of upper atmosphere conditions like subsidence, in comparison to the role of surface forcings like soil moisture. We show that the atmospheric-oriented model (MXL-A-gs) outperforms the carbon storage-oriented model (MXL-GECROS) on this diurnal scale. This performance strongly depends on the sensitivity of the modelled stomatal conductance to water stress, which is implemented differently in each model. This sensitivity also influences the magnitude of the surface fluxes of CO2, water and heat (surface control), and subsequently impacts the boundary-layer growth and entrainment fluxes (upper atmosphere control), which alter the atmospheric state. These findings suggest that observed CO2 mole fractions in the boundary layer can reflect strong influences of both the surface and upper atmospheric conditions, and the interpretation of CO2 mole fraction variations depends on the assumed land-surface coupling. We illustrate this with a sensitivity analysis where increased subsidence, typical for periods of drought, can induce a change of 12 ppm in atmospheric CO2 mole fractions, solely by decreasing the boundary-layer volume. The effect of such high subsidence on the Bowen ratio is of the same magnitude as induced by the depletion of soil moisture that would typically occur during a corresponding drought event. Correctly including such two-way land-surface interactions on the diurnal scale can thus potentially improve our understanding and interpretation of observed variations in atmospheric CO2, as well as improve crop yield forecasts by better describing the water loss and carbon gain.
Comparison of seven packages that compute ocean carbonate chemistry
Authors: Orr J. C. , Epitalon J.-M. , Gattuso J.-P.
Published: April 2014

Abstract. To study ocean acidification and the carbon cycle, marine scientists often use two measured or modeled carbonate system variables to compute others. These carbonate chemistry calculations, based on well-known thermodynamic equilibria, are now available from seven public packages: CO2SYS, csys, seacarb, swco2, CO2calc, ODV, and mocsy. We compared results from these packages using common input data and the set of equilibrium constants recommended for best practices. All packages agree within ±0.00025 units for pH and ±0.5 μmol kg−1 for CO32−, and six packages agree within ±0.2 μatm for pCO2 in terms of zonal-mean surface values. In the remaining package (csys), the surface pCO2 variable is up to 1.4 μatm lower than in other packages, but that is because it is mislabeled. When compared to surface fCO2, it differs by less than 0.2 μatm. The csys deviations in fCO2, pH, and CO32− grow with depth but remain small. Another package (swco2) also diverges significantly but only in warm deep waters as found in the Mediterranean Sea. Discrepancies between packages derive largely from their code for the equilibrium constants. Analysis of the sensitivity of each computed variable to changes in each constant showed the expected dominance of K1 and K2, while also revealing comparable sensitivity to KB, e.g., with the AT–CT input pair. Best-practice formulations for K1 and K2 are implemented consistently among packages, except those in csys deviate slightly at depth (e.g., 0.5% larger values at 4000 db) due to its pressure corrections made on the total instead of the seawater pH scale. With more recent formulations for K1 and K2 designed to cover a wider range of salinities, packages disagree more, e.g., by 8 μatm in pCO2, 1 μmol kg−1 in CO32−, and 0.006 units in pH under typical surface conditions. These discrepancies stem from packages using different sets of coefficients for the corresponding salinity dependence of the new formulations. Although each set should be equally viable after simple conversions, we show they are fundamentally inconsistent. Despite general agreement between current packages, agreement was much worse with outdated versions, e.g., differences reached up to 2.5 μatm in pCO2, 1.4 μmol kg−1 in CO32−, and 0.007 units in pH for surface zonal means when using the best-practice constants.
Evolution of the large-scale atmospheric circulation in response to changing ice sheets over the last glacial cycle
Authors: Löfverström M. , Caballero R. , Nilsson J. , Kleman J.
Published: April 2014

Abstract. We present modelling results of the atmospheric circulation at the cold periods of marine isotope stage 5b (MIS 5b), MIS 4 and the Last Glacial Maximum (LGM), as well as the interglacial. The paleo-simulations are forced by ice sheet reconstructions consistent with geological evidence and by appropriate insolation and greenhouse gas concentrations. The results suggest that the large-scale atmospheric winter circulation remained largely similar to the interglacial for a significant part of the glacial cycle. The proposed explanation is that the ice sheets were located in areas where their interaction with the mean flow is limited. However, the LGM Laurentide Ice Sheet induces a much larger planetary wave that leads to a zonalisation of the Atlantic jet. In summer, the ice sheet topography dynamically induces warm temperatures in Alaska and central Asia that inhibits the expansion of the ice sheets into these regions. The warm temperatures may also serve as an explanation for westward propagation of the Eurasian Ice Sheet from MIS 4 to the LGM.
Representation of climate extreme indices in the ACCESS1.3b coupled atmosphere–land surface model
Authors: Lorenz R. , Pitman A. J. , Donat M. G. , Hirsch A. L. , Kala J. , Kowalczyk E. A. , Law R. M. , Srbinovsky J.
Published: April 2014

Abstract. Climate extremes, such as heat waves and heavy precipitation events, have large impacts on ecosystems and societies. Climate models provide useful tools for studying underlying processes and amplifying effects associated with extremes. The Australian Community Climate and Earth System Simulator (ACCESS) has recently been coupled to the Community Atmosphere Biosphere Land Exchange (CABLE) model. We examine how this model represents climate extremes derived by the Expert Team on Climate Change Detection and Indices (ETCCDI) and compare them to observational data sets using the AMIP framework. We find that the patterns of extreme indices are generally well represented. Indices based on percentiles are particularly well represented and capture the trends over the last 60 years shown by the observations remarkably well. The diurnal temperature range is underestimated, minimum temperatures (TMIN) during nights are generally too warm and daily maximum temperatures (TMAX) too low in the model. The number of consecutive wet days is overestimated, while consecutive dry days are underestimated. The maximum consecutive 1-day precipitation amount is underestimated on the global scale. Biases in TMIN correlate well with biases in incoming longwave radiation, suggesting a relationship with biases in cloud cover. Biases in TMAX depend on biases in net shortwave radiation as well as evapotranspiration. The regions and season where the bias in evapotranspiration plays a role for the TMAX bias correspond to regions and seasons where soil moisture availability is limited. Our analysis provides the foundation for future experiments that will examine how land-surface processes contribute to these systematic biases in the ACCESS modelling system.
An efficient method for discerning climate-relevant sensitivities in atmospheric general circulation models
Authors: Wan H. , Rasch P. J. , Zhang K. , Qian Y. , Yan H. , Zhao C.
Published: April 2014

Abstract. This paper explores the feasibility of an experimentation strategy for investigating sensitivities in fast components of atmospheric general circulation models. The basic idea is to replace the traditional serial-in-time long-term climate integrations by representative ensembles of shorter simulations. The key advantage of the proposed method lies in its efficiency: since fewer days of simulation are needed, the computational cost is less, and because individual realizations are independent and can be integrated simultaneously, the new dimension of parallelism can dramatically reduce the turnaround time in benchmark tests, sensitivities studies, and model tuning exercises. The strategy is not appropriate for exploring sensitivity of all model features, but it is very effective in many situations. Two examples are presented using the Community Atmosphere Model version 5. The first example demonstrates that the method is capable of characterizing the model cloud and precipitation sensitivity to time step length. A nudging technique is also applied to an additional set of simulations to help understand the contribution of physics-dynamics interaction to the detected time step sensitivity. In the second example, multiple empirical parameters related to cloud microphysics and aerosol lifecycle are perturbed simultaneously in order to explore which parameters have the largest impact on the simulated global mean top-of-atmosphere radiation balance. Results show that in both examples, short ensembles are able to correctly reproduce the main signals of model sensitivities revealed by traditional long-term climate simulations for fast processes in the climate system. The efficiency of the ensemble method makes it particularly useful for the development of high-resolution, costly and complex climate models.
Influence of major fault zones on 3-D coupled fluid and heat transport for the Brandenburg region (NE German Basin)
Authors: Cherubini Y. , Cacace M. , Scheck-Wenderoth M. , Noack V.
Published: April 2014

Abstract. To quantify the influence of major fault zones on the groundwater and thermal field, 3-D finite-element simulations are carried out. Two fault zones – the Gardelegen and Lausitz escarpments – have been integrated into an existing 3-D structure of the Brandenburg region in northeastern Germany. Different geological scenarios in terms of modelled fault permeability have been considered, of which two end-member models are discussed in detail. In addition, results from these end-member simulations are compared to a reference case in which no faults are considered.

 The study provides interesting results with respect to the interaction between faults and surrounding sediments and how it affects the regional groundwater circulation system and thermal field.

 Impermeable fault zones seem to induce no remarkable effects on the temperature distribution; that is, the thermal field is similar to the no-fault model. In addition, tight faults have only a local impact on the fluid circulation within a domain of limited spatial extent centred on the fault zone. Fluid flow from the surrounding aquifers is deviated in close proximity of the fault zones acting as hydraulic barriers that prevent lateral fluid inflow into the fault zones.

 Permeable fault zones induce a pronounced thermal signature with alternating up- and downward flow along the same structures. Fluid flow along the plane of the faults is principally driven by existing hydraulic head gradients, but may be further enhanced by buoyancy forces. Within recharge domains, fluid advection induces a strong cooling in the fault zones. Discharge domains at shallow depth levels (~<−450 m) are instead characterized by the presence of rising warm fluids, which results in a local increase of temperatures which are up to 15 °C higher than in the no-fault case.

 This study is the first attempt to investigate the impact of major fault zones on a 3-D basin scale for the coupled fluid and heat transport in the Brandenburg region. The approach enables a quantification of mechanisms controlling fluid flow and temperature distribution both within surrounding sediments and fault zones as well as how they dynamically interact. Therefore, the results from the modelling provide useful indications for geothermal energy exploration.
Comparing impacts of climate change on streamflow in four large African river basins
Authors: Aich V. , Liersch S. , Vetter T. , Huang S. , Tecklenburg J. , Hoffmann P. , Koch H. , Fournet S. , Krysanova V. , Müller E. N. , Hattermann F. F.
Published: April 2014

Abstract. This study aims to compare impacts of climate change on streamflow in four large representative African river basins: the Niger, the Upper Blue Nile, the Oubangui and the Limpopo. We set up the eco-hydrological model SWIM (Soil and Water Integrated Model) for all four basins individually. The validation of the models for four basins shows results from adequate to very good, depending on the quality and availability of input and calibration data. For the climate impact assessment, we drive the model with outputs of five bias corrected Earth system models of Coupled Model Intercomparison Project Phase 5 (CMIP5) for the representative concentration pathways (RCPs) 2.6 and 8.5. This climate input is put into the context of climate trends of the whole African continent and compared to a CMIP5 ensemble of 19 models in order to test their representativeness. Subsequently, we compare the trends in mean discharges, seasonality and hydrological extremes in the 21st century. The uncertainty of results for all basins is high. Still, climate change impact is clearly visible for mean discharges but also for extremes in high and low flows. The uncertainty of the projections is the lowest in the Upper Blue Nile, where an increase in streamflow is most likely. In the Niger and the Limpopo basins, the magnitude of trends in both directions is high and has a wide range of uncertainty. In the Oubangui, impacts are the least significant. Our results confirm partly the findings of previous continental impact analyses for Africa. However, contradictory to these studies we find a tendency for increased streamflows in three of the four basins (not for the Oubangui). Guided by these results, we argue for attention to the possible risks of increasing high flows in the face of the dominant water scarcity in Africa. In conclusion, the study shows that impact intercomparisons have added value to the adaptation discussion and may be used for setting up adaptation plans in the context of a holistic approach.
Spatiotemporal multifractal characteristics of electromagnetic radiation in response to deep coal rock bursts
Authors: Shaobin H. , Enyuan W. , Xiaofei L.
Published: April 2014

Abstract. Dynamic collapses of deeply mined coal rocks are severe threats to miners, in order to predict the collapses more accurately using electromagnetic radiation (EMR), we investigate the spatiotemporal multifractal characteristics and formation mechanism of EMR induced by underground coal mining. Coal rock in the burst-prone zone often exchanges materials and energy with its environment and gradually transits from its original stable equilibrium structure to a non-equilibrium dissipative structure with implicit spatiotemporal complexity or multifractal structures, resulting in temporal variation in multifractal EMR. The inherent law of EMR time series during damage evolution was analyzed by using time-varying multifractal theory. Results show that the time-varying multifractal characteristics of EMR are determined by damage evolutions process, the dissipated energy caused by damage evolutions such as crack propagation, fractal sliding and shearing can be regarded as the fingerprint of various EMR micro-mechanics. Dynamic spatiotemporal multifractal spectrum of EMR considers both spatial (multiple fractures) and temporal (dynamic evolution) characteristics of coal rocks, and records the dynamic evolution processes of rock bursts. Thus, it can be used to evaluate the coal deformation and fracture process. The study is of significance for us to in-depth understand EMR mechanism and to increase the accuracy of applying the EMR method to forecast dynamic disasters.
Generalized binomial multiplicative cascade processes and asymmetrical multifractal distributions
Authors: Cheng Q.
Published: April 2014

Abstract. The concepts and models of multifractals have been employed in various fields in the geosciences to characterize singular fields caused by nonlinear geoprocesses. Several indices involved in multifractal models, i.e., asymmetry, multifractality, and range of singularity, are commonly used to characterize nonlinear properties of multifractal fields. An understanding of how these indices are related to the processes involved in the generation of multifractal fields is essential for multifractal modeling. In this paper, a five-parameter binomial multiplicative cascade model is proposed based on the anisotropic partition processes. Each partition divides the unit set (1-D length or 2-D area) into h equal subsets (segments or subareas) and m1 of them receive d1 (> 0) and m2 receive d2 (> 0) proportion of the mass in the previous subset, respectively, where m1+m2 ≤ h. The model is demonstrated via several examples published in the literature with asymmetrical fractal dimension spectra. This model demonstrates the various properties of asymmetrical multifractal distributions and multifractal indices with explicit functions, thus providing insight into and an understanding of the properties of asymmetrical binomial multifractal distributions.
Multiple scale error growth in a convection-resolving model
Authors: Uboldi F. , Trevisan A.
Published: April 2014

Abstract. The properties of the multiple scale instabilities present in a non-hydrostatic forecast model are investigated. The model simulates intense convection episodes occurring in Northern Italy. A breeding technique is used to construct ensembles of perturbations of the model trajectories aimed to represent the instabilities that are responsible for error growth at various time and space scales. It is found that for initial errors of the order of present-day analysis error, error growth is mainly determined by intermediate scale instabilities, and that a non-negligible fraction of the forecast error can be explained by an ensemble of bred vectors of reasonable size. In contrast, when the initial error is much smaller, the spectrum of bred vectors representing the fast convective-scale instabilities becomes flat and the number of ensemble members needed to explain even a small fraction of the forecast error becomes extremely large. The conclusion is that as the analysis error is decreased, it becomes more and more computationally demanding to construct an ensemble that can describe the high-dimensional subspace of convective instabilities and that can thus be potentially useful for controlling the error growth.
Sensitivity of the dynamics of Pine Island Glacier, West Antarctica, to climate forcing for the next 50 years
Authors: Seroussi H. , Morlighem M. , Rignot E. , Mouginot J. , Larour E. , Schodlok M. P. , Khazendar A.
Published: April 2014

Abstract. Pine Island Glacier, a major contributor to sea level rise in West Antarctica, has been undergoing significant changes over the last few decades. Here, we employ a three-dimensional, higher-order model to simulate its evolution over the next fifty years in response to changes in its surface mass balance, the position of its calving front and ocean-induced ice shelf melting. Simulations show that the largest climatic impact on ice dynamics is the rate of ice shelf melting, which rapidly affects the glacier speed over several hundreds of kilometers upstream of the grounding line. Our simulations show that the speedup observed in the 1990s and 2000s is consistent with an increase in sub-ice-shelf melting. According to our modeling results, Pine Island Glacier will continue to change rapidly over the coming decades and remain a major contributor to sea level rise, even if ocean-induced melting is reduced.
The Foundations Supporting Biofeedback and Neurofeedback: Why Collaborative Research?
Authors: Kerson Cynthia
Published: April 2014

Research in the field of biofeedback is not always effective for the development of the field. In particular, neurofeedback has had spotty success, with many studies failing to meet rigorous methodological standards. Many researchers are lacking in the basic understanding of neuromodulation and its inherent learning model. And many clinicians, while knowledgeable in clinical applications, lack understanding of the rigors of good research. However, the International Society for Neurofeedback and Research (ISNR) Foundation and the Association for Applied Psychophysiology and Biofeedback (AAPB) Foundation for Education and Research in Biofeedback are rich in expertise, yet that expertise is seldom tapped. The following interview with the president of the ISNR Research Foundation, David Trudeau, will spotlight the foundation's impact on the field of neurofeedback. A second interview with Paul Lehrer, Chair of AAPB's Foundation for Education and Research in Biofeedback (FERB) will appear in the summer 2014 issue of Biofeedback. It is hoped that this interview series will provide insight to both foundations and facilitate future collaboration.
Making the Unaware Aware: Surface Electromyography to Unmask Tension and Teach Awareness
Authors: Peper Erik , Booiman Annette , Lin I-Mei , Shaffer Fred
Published: April 2014

Poor awareness of covert low-level muscle tension and poor ergonomics can result in chronic muscle bracing and the development of clinical symptoms. This article introduces a simple exercise to teach awareness and control of residual muscle contraction, presents evidence of its effectiveness, and concludes with a case study in which this exercise contributed to the treatment of severe pelvic girdle pain. The authors warn against becoming “captured” by tasks and adjusting to bad ergonomics, and emphasize the importance of enhancing somatic awareness to correct dysponesis before it results in pain and disability.
What BCIA Learned from Bob Dylan
Authors: Crawford Judy , Shaffer Fred
Published: April 2014

Biofeedback and neurofeedback certification expanded internationally, and the Biofeedback Certification International Alliance (BCIA) revised both recertification and certification programs in 2013. This article examines the main engines that have fueled certification growth: the BCIA affiliate program, the international expansion of BCIA-accredited training programs, and international educational and scientific society meetings held by the Society for Applied Neuroscience and the Biofeedback Federation of Europe. The authors conclude with a review of recent changes in recertification, academic certification, and the Neurofeedback Blueprint and a progress report on BCIA's HRV Biofeedback Certificate of Completion, Board Certified Practitioner and Mentor Directory, and Job Board programs.
Global Observer-Based Attitude Controller Using Direct Inertial Measurements
Authors: Bouhired Saâdi , Bouchoucha Mouloud , Tadjine Mohamed
Published: April 2014

In this work, we address the problem of global attitude control using direct inertial measurements. When using direct inertial measurement to observe the rigid body attitude, it is shown that due to a geometrical obstruction, it is impossible to achieve global asymptotic stability. In fact, for a particular initial condition the tracking error quaternion converges to a pure imaginary quaternion formed by an eigenvector of a characteristic matrix related to the inertial constant and known vectors. Our proposition consists of adding a dynamic signal to force the rigid body to escape from such a situation. The proposed observer-based controller is synthesized based on a single Lyapunov function and a stability analysis shows that the controller stabilizes globally and asymptotically the rigid body attitude at the desired one. The effectiveness of the proposed observer-based controller is confirmed by simulation results.
A Panoramic 3D Reconstruction System Based on the Projection of Patterns
Authors: Córdova-Esparza Diana-Margarita , Gonzalez-Barbosa José-Joel , Hurtado-Ramos Juan-Bautista , Ornelas-Rodriguez Francisco-Javier
Published: April 2014

This work presents the implementation of a 3D reconstruction system capable of reconstructing a 360-degree scene with a single acquisition using a projection of patterns. The system is formed by two modules: the first module is a CCD camera with a parabolic mirror that allows the acquisition of catadioptric images. The second module consists of a light projector and a parabolic mirror that is used to generate the pattern projections over the object that will be reconstructed. The projection system has a 360-degree field of view and both modules were calibrated to obtain the extrinsic parameters. To validate the functionality of the system, we performed 3D reconstructions of three objects, and show the reconstruction error analysis.
Flexible Robotic Spine Actuated by Shape Memory Alloy
Authors: Wang Shiquan , Zhu Qiuguo , Xiong Rong , Chu Jian
Published: April 2014

A flexible robotic spine actuated by shape memory alloy (SMA) can achieve both bending motion and impact absorption, which will allow robots to realize a variety of postures. In this paper, the robotic spine is designed and simplified into a multi-segment dynamic model based on several verified assumptions. The SMA wire is modelled using the Seelecke-Muller-Acenbach theory. An iterative algorithm is developed to address the external forces distributed along the spine and compute the spine's bending angle. Based on the dynamic model, we improve the simulation structure and search algorithm to achieve good efficiency and stable solutions. Experiments are conducted to verify the simulation and the results fit the simulation prediction well, with error of less than five degrees. Design optimization with our simulation tool based on several parameters is also discussed in this paper.
Longitudinal Plasmonic Detection of Glucose Using Gold Nanorods
Authors: Peng Ching-An , Pachpinde Sushil
Published: April 2014

Gold nanorod-based affinity sensors were developed utilizing concanavalin-A/dextran/glucose chemistry to detect glucose. The gold nanorods, synthesized using the seed-mediated method, were first coated with dextran sulfate. The dextran sulfate coating changed the local refractive index, which was observed as a red shift in the longitudinal plasmon band. After the addition of 8 μM concanavalin-A, gold nanorod aggregates were formed as shown by TEM analysis. The corresponding UV-Vis spectrum peak wavelength showed a red shift from 701 nm of dextran sulfate coated gold nanorods to 718 nm of concanavalin-A promoted gold nanorod aggregates. The gold nanorod aggregates were dissociated when 12 mM glucose was introduced, as illustrated by TEM images. The longitudinal plasmon resonance of the UV-Vis spectrum also showed a blue shift from 718 nm of dextran sulfate-coated gold nanorods associated by concanavalin-A to 714 nm of dissociated dextran sulfate-coated gold nanorods. The degree of the spectrum peak wavelength shift of the dextran sulfate-coated gold nanorods associated by concanavalin-A can be modulated using glucose ranging from 1 to 30 mM.
Cavitation and head loss characteristics in nonsymmetric bifurcations
Authors: Daniels Steven E. , Johnson Michael C. , Spall Robert E.
Published: April 2014

Nonsymmetric bifurcations, commonly used in piping systems to divert flow from one pipe to another, see considerable use in hydroelectric power applications and low‐level outlet works at dams. Under normal operation, cavitation at the bifurcation likely is not an issue; however, during emergency releases for dam safety or other extreme flows, the bifurcation must be able to safely pass the required flows without incurring damage attributable to cavitation. Although nonsymmetric bifurcations are widely used, the authors are unaware of any published data on related cavitation characteristics. The current study used computational fluid dynamics in conjunction with a physical model to predict conditions that would cause the onset of cavitation and to calculate head loss coefficients. Operating conditions are recommended that will allow bifurcations to operate within safe limits of cavitation. This study, although not exhaustive, provides previously unavailable data and can help designers and operators better understand the hydraulic performance of bifurcations.
Using process models to estimate residential water use and population served
Authors: Friedman Kenneth , Heaney James P , Morales Miguel
Published: April 2014

A key measure of efficiency in the field of urban water demand is gallons per capita per day of water use. One popular metric, gross gallons per capita per day, can be misleading because it includes nonresidential water uses. As an alternative, this article addresses the calculation of residential water use defined as the product of population and per capita use associated solely with people who are physically present and using water in single‐family and multifamily residences at a given time. This approach allows for consistent benchmarking because per capita use multiplied by population yields the actual amount of water delivered to the residential sector. Process models for residential population and indoor and outdoor per capita water use can be used to estimate total residential water use if they incorporate the variability among fixture end uses and irrigable area for every household served by a utility. When this approach was applied to the Sanford, Fla., case study area, the process models predicted single‐ and multifamily water use with reasonable accuracy.
Modeling conservative contaminant effects on reservoir water quality
Authors: Jeznach Lillian C. , Tobiason John E. , Ahlfeld David P
Published: April 2014

The Wachusett Reservoir in central Massachusetts was modeled using the two‐dimensional CEQUAL‐W2 hydrodynamic and water quality model to simulate a conservative contaminant spill from a roadway and analyze contaminant behavior at the Cosgrove drinking water intake 12.5 km (7.8 mi) from the spill site. Modeled calendar years 2003–09 were developed using meteorology, bathymetry, inflow quantity and quality, and outflow quantity data. Scenarios investigated included the influence of season, spill density, additional water transferred from Quabbin Reservoir, and wind on contaminant transport. Contaminants arrived at the intake much earlier than the mean hydraulic residence time. Contaminant concentrations were greater and more variable during the summer. Turning the Quabbin transfer off decreased the variability in concentration at the intake, especially during the summer. Model results provide useful information to reservoir operators for how to respond to potential contaminant spills under various scenarios.
We are growing
Authors: Zippin Liat , Englard Lisa
Published: April 2014

Math by the Month is a regular department of the journal. It features collections of short activities focused on a monthly theme. These articles aim for an inquiry or problem-solving orientation that includes at least four activities each for grade bands K—2, 3—4, and 5—6. In this issue, the problems capitalize on the natural curiosity of children to explore measurement.
Les services de santé en français pour les communautés francophones et acadiennes en situation minoritaire du Canada : bonification du schéma du CCCFSM (2001)
Authors: Giguère Louis
Published: April 2014

Nous bonifions le schéma du CCCFSM (2001) sur le développement des services de santé en français pour les communautés francophones et acadiennes en situation minoritaire (CFASM) du Canada à l’aide de données probantes recueillies lors du recensement national de 2006. Notre approche consiste à choisir, à partir d’une procédure statistique, une mesure de masse critique de francophones qui met en évidence un schème cohérent d’offre et de demande de services de santé sur une base géographique juridictionnelle. L’offre et la demande sont plus grandes là où la vitalité linguistique des CFASM est plus grande. Dans l’ensemble, l’offre tombe en deçà de la demande; ceci suggère une demande latente de services en français et est consistant avec les études d’offre active des services en français dans les CFASM. Nos résultats sont aussi consistants avec les trois phases évolutives de sensibilisation, de structuration et de consolidation proposées par le CCCFSM (2001). Nous discutons des limitations méthodologiques et en tirons des leçons pour les réseaux de santé francophones des CFASM.
Efeitos de fatores ambientais sobre a germinação de sementes de Nymphoides indica (L.) O. Kuntze (Menyanthaceae)
Authors: Batista Thasiana de Lima , Freire Marcio de Araújo , Magalhães Ubiracy Allan Sousa , Colares Ioni Gonçalves
Published: April 2014

Nymphoides indica e uma macrófita aquática de distribuição pantropical cosmopolita. Neste trabalho avaliamos a influencia da temperatura, fotoperíodo e soterramento na germinação de sementes de N. indica. Amostras de sementes foram coletadas no Lago Sete, localizado no Campus Carreiros da Universidade Federal do Rio Grande – FURG. A viabilidade foi testada em amostras de 25 sementes com 0, 30, 60 dias de armazenamento utilizando o teste de tetrazolio. Sementes com 0, 30, 60 dias foram submetidas a temperaturas alternadas de 10 °CD-05 oCN; 15 °CD-05 °CN; 15 °CD-10 °CN; 20 °CD-10 °CN; 20 oCD-15 °CN; 25 °CD-15 °CN; 25 °CD-20 °CN; 30 °CD-20 °CN; 30 °CD-25 °CN (Diurna-Noturna) em fotoperíodo constante de 12hL-12hE (Luz-Escuro), durante 30 dias. Para cada teste, quatro replicas de 25 sementes foram acondicionadas em beckers preenchidos com agua do Lago Sete, ate a altura de 6 cm. A seguir as sementes foram submetidas a temperaturas de 20 °CD-15 °CN, 30 °CD-25 °CN, no escuro e nos fotoperíodos 10hL-14hE, 12hL-12hED e 14hL-10hE, e nos tratamentos de soterramento de 0,1 e 10 mm. Maiores temperaturas favoreceram a germinação, que foi inibida nas temperaturas de 10 °CD-05 °CN. Na temperatura de 20 °CN-15 °CD a porcentagem de germinação (PG) e a taxa de germinação (TG) aumentou significativamente (p < 0,05), por causa da exposição a luz. Em 30 °CD-25 °CN, os valores de PG e TG não apresentaram mudanças significativas nos diferentes tratamentos de luz. Sob soterramento, as sementes germinaram em todas as profundidades testadas, com maior PG no soterramento zero, temperatura de 20 °CD-15 °CN e fotoperíodo de 10hL-14hE. Os resultados obtidos neste estudo mostram que temperaturas alternadas e luz favorecem a germinação.
Fatores determinantes na distribuição de Bunodosoma caissarum Corrêa in Belém, 1987 (Cnidaria, Actiniaria) em um costão rochoso na costa sudeste do Brasil
Authors: Scremin Renata , Furquim Suelen , Dubiaski-Silva Janete
Published: April 2014

Aspectos ecológicos de Bunodosoma caissarum foram estudados em um costão rochoso no Morro do Cristo, em Guaratuba (PR), Paraná, no período de outubro de 2008 a setembro de 2009, com o objetivo de avaliar a influência de parâmetros bióticos e abióticos sobre sua distribuição. Foram mensurados: umidade e temperatura do ar, luminosidade e posição dos indivíduos na rocha. Também foram quantificadas fauna e flora associadas, bem como as densidades das anêmonas e os diâmetros de seus discos pedais. A temperatura do ar mostrou ampla variação, enquanto que umidade, luminosidade e posição relativa das anêmonas na rocha apresentaram faixas mais restritas. Os três primeiros fatores estão relacionados com dessecação, enquanto que o último relaciona-se com proteção contra o embate das ondas. Verificou-se que quanto maior a umidade do ar menor será a temperatura no microambiente, favorecendo assim a ocorrência das anêmonas. Foi constatado que anêmonas menores possuem a tendência de formarem agrupamentos, pois dessa forma concentram umidade garantindo-lhes melhores condições de sobrevivência. Foram registrados 23 táxons associados a B. caissarum (15 macroinvertebrados e oito macroalgas), sendo os mais frequentes Phragmatopoma caudata, Gymnogongrus griffithsiae e Brachidontes solisianus. O compartilhamento de microhábitats com táxons específicos foi característico em todo o estudo, demonstrando que a tendência destes cnidários formarem agregados interespecíficos também pode ser uma estratégia contra a dessecação.
Análise da geração e destinação de resíduos sólidos do município de Pinhais, Paraná, Brasil
Authors: Reus Thaís Cristhine , Piovesan Eleni Juliato
Published: April 2014

O presente estudo apresenta uma análise quantitativa dos resíduos sólidos (domiciliar, reciclável, verde e hospitalar) gerados pelo município de Pinhais de 2006 a 2010. Registrou-se um aumento progressivo em todos os tipos de resíduos gerados durante o período, sendo 2010 com maior média, principalmente na coleta de lixo reciclável. O aumento verificado na geração de resíduos demanda melhorias nos programas de educação ambiental em andamento, que visem à conscientização dos munícipes em relação à separação correta do lixo, bem como a elaboração de planos e metas visando a redução do lixo gerado e, consequentemente, uma redução de custos. A adoção de soluções políticas e tecnológicas adequadas é fundamental para o gerenciamento dos resíduos sólidos urbanos. Isso constitui um desafio a ser encarado não somente pelo poder público, mas também pela sociedade como um todo.