bluuebunny/crossref_metadata_2025 huggingface dataset:
Bed topography of Princess Elizabeth Land in East Antarctica
Authors: Cui Xiangbin , Jeofry Hafeez , Greenbaum Jamin S. , Guo Jingxue , Li Lin , Lindzey Laura E. , Habbal Feras A. , Wei Wei , Young Duncan A. , Ross Neil , Morlighem Mathieu , Jong Lenneke M. , Roberts Jason L. , Blankenship Donald D. , Bo Sun , Siegert Martin J.
Published: November 2020

Abstract. We present a topographic digital elevation model (DEM) for Princess
Elizabeth Land (PEL), East Antarctica. The DEM covers an area of
∼900 000 km2 and was built from radio-echo
sounding data collected during four campaigns since 2015. Previously, to
generate the Bedmap2 topographic product, PEL's bed was characterized from
low-resolution satellite gravity data across an otherwise large
(>200 km wide) data-free zone. We use the mass conservation (MC)
method to produce an ice thickness grid across faster flowing (>30 m yr−1) regions of the ice sheet and streamline diffusion in slower flowing areas. The resulting ice thickness model is integrated with an ice surface model to build the bed DEM. Together with BedMachine
Antarctica and Bedmap2, this new bed DEM completes the first-order
measurement of subglacial continental Antarctica – an international mission that began around 70 years ago. The ice thickness data and bed DEMs of PEL (resolved horizontally at 500 m relative to ice surface elevations obtained from the Reference Elevation Model of Antarctica – REMA) are accessible from https://doi.org/10.5281/zenodo.4023343 (Cui et al., 2020a) and https://doi.org/10.5281/zenodo.4023393 (Cui et al., 2020b).
Measurements of hydrodynamics, sediment, morphology and benthos on Ameland ebb-tidal delta and lower shoreface
Authors: van Prooijen Bram C. , Tissier Marion F. S. , de Wit Floris P. , Pearson Stuart G. , Brakenhoff Laura B. , van Maarseveen Marcel C. G. , van der Vegt Maarten , Mol Jan-Willem , Kok Frank , Holzhauer Harriette , van der Werf Jebbe J. , Vermaas Tommer , Gawehn Matthijs , Grasmeijer Bart , Elias Edwin P. L. , Tonnon Pieter Koen , Santinelli Giorgio , Antolínez José A. A. , de Vet Paul Lodewijk M. , Reniers Ad J. H. M. , Wang Zheng Bing , den Heijer Cornelis , van Gelder-Maas Carola , Wilmink Rinse J. A. , Schipper Cor A. , de Looff Harry
Published: November 2020

Abstract. A large-scale field campaign was carried out on the ebb-tidal delta (ETD) of Ameland Inlet, a basin of the Wadden Sea in the Netherlands, as well as on three transects along the Dutch lower shoreface. The data have been obtained over the years 2017–2018. The most intensive campaign at the ETD of Ameland Inlet was in September 2017. With this campaign, as part of KustGenese2.0 (Coastal Genesis 2.0) and SEAWAD, we aim to gain new knowledge on the processes driving sediment transport and benthic species distribution in such a dynamic environment. These new insights will ultimately help the development of optimal strategies to nourish the Dutch coastal zone in order to prevent coastal erosion and keep up with sea level rise.
The dataset obtained from the field campaign consists of (i) single- and multi-beam bathymetry; (ii) pressure, water velocity, wave statistics, turbidity, conductivity, temperature, and bedform morphology on the shoal; (iii) pressure and velocity at six back-barrier locations; (iv) bed composition and macrobenthic species from box cores and vibrocores; (v) discharge measurements through the inlet; (vi) depth and velocity from X-band radar; and (vii) meteorological data. The combination of all these measurements at the same time makes this dataset unique and enables us to investigate the interactions between sediment transport, hydrodynamics, morphology and the benthic ecosystem in more detail. The data provide opportunities to calibrate numerical models to a high level of detail. Furthermore, the open-source datasets can be used for system comparison studies. The data are publicly available at 4TU Centre for Research Data at https://doi.org/10.4121/collection:seawad (Delft University of Technology et al., 2019) and https://doi.org/10.4121/collection:kustgenese2 (Rijkswaterstaat and Deltares, 2019). The datasets are published in netCDF format and follow conventions for CF (Climate and Forecast) metadata. The http://data.4tu.nl (last access: 11 November 2020) site provides keyword searching options and maps with the geographical position of the data.
Greenland liquid water discharge from 1958 through 2019
Authors: Mankoff Kenneth D. , Noël Brice , Fettweis Xavier , Ahlstrøm Andreas P. , Colgan William , Kondo Ken , Langley Kirsty , Sugiyama Shin , van As Dirk , Fausto Robert S.
Published: November 2020

Abstract. Greenland runoff, from ice mass loss and increasing rainfall, is increasing. That runoff, as discharge, impacts the physical, chemical, and biological properties of the adjacent fjords. However, where and when the discharge occurs is not readily available in an open database. Here we provide data sets of high-resolution Greenland hydrologic outlets, basins, and streams, as well as a daily 1958 through 2019 time series of Greenland liquid water discharge for each outlet. The data include 24 507 ice marginal outlets and upstream basins and 29 635 land coast outlets and upstream basins, derived from the 100 m ArcticDEM and 150 m BedMachine. At each outlet there are daily discharge data for 22 645 d – ice sheet runoff routed subglacially to ice margin outlets and land runoff routed to coast outlets – from two regional climate models (RCMs; MAR and RACMO).
Our sensitivity study of how outlet location changes for every inland cell based on subglacial routing assumptions shows that most inland cells where runoff occurs are not highly sensitive to those routing assumptions, and outflow location does not move far. We compare RCM results with 10 gauges from streams with discharge rates spanning 4 orders of magnitude. Results show that for daily discharge at the individual basin scale the
5 % to 95 % prediction interval between modeled discharge and observations generally falls within plus or minus a factor of 5 (half an order of magnitude, or +500 %/-80 %). Results from this study are available at
https://doi.org/10.22008/promice/freshwater (Mankoff, 2020a) and code is available at http://github.com/mankoff/freshwater (last access: 6 November 2020) (Mankoff, 2020b).
Surface and subsurface characterisation of salt pans expressing polygonal patterns
Authors: Lasser Jana , Nield Joanna M. , Goehring Lucas
Published: November 2020

Abstract. The data set described here contains information about the surface, subsurface, and environmental conditions of salt pans that express polygonal patterns in their surface salt crust (Lasser et al., 2020b; https://doi.org/10.5880/fidgeo.2020.037). Information stems from 5 field sites at Badwater Basin and 21 field sites at Owens Lake – both in central California. All data were recorded during two field campaigns from between November and December 2016 and in January 2018. Crust surfaces, including the mean diameter and fluctuations in the height of the polygonal patterns, were characterised by a terrestrial laser scanner (TLS). The data contain the resulting three-dimensional point clouds that describe these surfaces. The subsurface is characterised by grain size distributions of samples taken from depths between 5 and 100 cm below the salt crust and measured with a laser particle size analyser. Subsurface salinity profiles were recorded, and the groundwater density was also measured. Additionally, the salts present in the crust and pore water were analysed to determine their composition. To characterise the environmental conditions at Owens Lake, including the differences between nearby crust features, records were made of the temperature and relative humidity during 1 week in November 2016. The field sites are characterised by images showing the general context of each site, such as pictures of selected salt polygons, including any which were sampled, a typical core from each site at which core samples were taken, and close-ups of the salt crust morphology. Finally, two videos of salt crust growth over the course of spring 2018 and reconstructed from time lapse images are included.
MOSAIC (Modern Ocean Sediment Archive and Inventory of Carbon):
A (radio)carbon-centric database for seafloor surficial sediments
Authors: van der Voort Tessa Sophia , Blattmann Thomas M. , Usman Muhammed , Montluçon Daniel , Loeffler Thomas , Tavagna Maria Luisa , Gruber Nicolas , Eglinton Timothy Ian
Published: November 2020

Abstract. Mapping the biogeochemical characteristics of surficial ocean sediments is crucial for advancing our understanding of global element cycling, as well as for assessment of the potential footprint of environmental change. Despite their importance as long-term repositories for biogenic materials produced in the ocean and delivered from the continents, biogeochemical signatures in ocean sediments remain poorly delineated. Here, we introduce MOSAIC (Modern Ocean Sediment Archive and Inventory of Carbon; DOI: https://doi.org/10.5168/mosaic019.1, mosaic.ethz.ch, Van der Voort et al., 2019), a (radio)carbon-centric database that seeks to address this information void. The goal of this nascent database is to provide a platform for development of regional to global-scale perspectives on the source, abundance and composition of organic matter in marine surface sediments, and to explore links between spatial variability in these characteristics and biological and depositional processes. The database has a continental margin-centric focus given both the importance and complexity of continental margins as sites of organic matter burial. It places emphasis on radiocarbon as an underutilized yet powerful tracer and chronometer of carbon cycle processes, and with a view to complementing radiocarbon databases for other earth system compartments. The database infrastructure and interactive web-application are openly accessible and designed to facilitate further expansion of the database. Examples are presented to illustrate large-scale variabilities in bulk carbon properties that emerge from the present data compilation.
Simulation of O3 and NOX in Sao Paulo street urban canyons with VEIN (v0.2.2) and MUNICH (v1.0)
Authors: Gavidia-Calderón Mario E. , Ibarra-Espinosa Sergio , Kim Youngseob , Zhang Yang , Andrade Maria de Fatima
Published: November 2020

Abstract. We evaluate the performance of the Model of Urban Network of Intersecting Canyons and Highways (MUNICH) in simulating Ozone (O3) and Nitrogen Oxides (NOx) concentrations within the urban street canyons in the Sao Paulo Metropolitan Area (SPMA). The MUNICH simulations are performed inside Pinheiros neighborhood (a residential area) and Paulista Avenue (an economic hub), which are representative urban canyons in the SPMA. Both zones have air quality stations maintained by the Sao Paulo Environmental Agency (CETESB), providing data (both pollutants concentrations and meteorological) for model evaluation. Meteorological inputs for MUNICH are produced by a simulation with the Weather Research and Forecasting model (WRF) over triple-nested domains with the innermost domain centered over the SPMA at a spatial grid resolution of 1 km. Street links coordinates and emission flux rates are retrieved from the Vehicular Emission Inventory (VEIN) emission model, representing the real fleet of the region. The VEIN model has an advantage to spatially represent emissions and present compatibility with MUNICH. Building height is estimated from the World Urban Database and Access Portal Tools (WUDAPT) Local Climate Zone map for SPMA. Background concentrations are obtained from the Ibirapuera air quality station located in an urban park. Finally, volatile organic compounds (VOCs) speciation is approximated using information from Sao Paulo air quality forecast emission file and non-methane hydrocarbons concentration measurements. Results show an overprediction of O3 concentrations in both study cases. NOx concentrations are underpredicted in Pinheiros but are better simulated in Paulista Avenue. Compared to O3, NO2 is better simulated in both urban zones. The O3 prediction is highly dependent on the background concentration, which is the main cause for the model O3 overprediction. The MUNICH simulations satisfy the performance criteria when emissions are calibrated. The results show the great potential of MUNICH to represent the concentrations of pollutants emitted by the fleet close to the streets. The street-scale air pollutant predictions make it possible in the future to evaluate the impacts on public health due to human exposure to primary exhaust gases pollutants emitted by the vehicles.
Evapotranspiration in the Amazon: spatial patterns, seasonality and
recent trends in observations, reanalysis and CMIP models
Authors: Baker Jessica C. A. , Garcia-Carreras Luis , Gloor Manuel , Marsham John H. , Buermann Wolfgang , da Rocha Humberto R. , Nobre Antonio D. , de Araujo Alessandro Carioca , Spracklen Dominick V.
Published: November 2020

Abstract. Water recycled through transpiring forests influences the spatial distribution of precipitation in the Amazon and has been shown to play a role in the initiation of the wet season. However, due to the challenges and costs associated with measuring evapotranspiration (ET) directly, plus the high uncertainty and discrepancies across remote-sensing retrievals of ET, spatial and temporal patterns in this key component of the Amazon hydrological cycle remain poorly understood. In this study, we estimated ET over the Amazon and ten sub-basins using a catchment-balance approach, whereby ET is calculated directly as the balance between precipitation, runoff and change in groundwater storage. We compared our results with ET from remote-sensing datasets, reanalysis, models from the fifth and sixth Coupled Model Intercomparison Projects (CMIP5 and CMIP6), and in-situ flux-tower measurements, to provide a comprehensive overview of current understanding. Catchment-balance analysis revealed a gradient in ET from east to west/southwest across the Amazon basin, a strong seasonal cycle in basin-mean ET controlled by net incoming radiation, and no trend in ET over the past two decades. Satellite datasets, reanalysis and climate models all tended to overestimate the magnitude of ET relative to catchment-balance estimates, underestimate seasonal and interannual variability, and show conflicting positive and negative trends. Only two out of six satellite and model datasets analysed reproduced spatial and seasonal variation in Amazon ET, and captured the same controls on ET as indicated by catchment-balance analysis. CMIP5 and CMIP6 ET was inconsistent with catchment-balance estimates over all scales analysed. Overall, the discrepancies between data products and models revealed by our analysis demonstrate a need for more ground-based ET measurements in the Amazon, and to substantially improve model representation of this fundamental component of the Amazon hydrological cycle.
Nonstationary weather and water extremes: a review of methods for
their detection, attribution, and management
Authors: Slater Louise J. , Anderson Bailey , Buechel Marcus , Dadson Simon , Han Shasha , Harrigan Shaun , Kelder Timo , Kowal Katie , Lees Thomas , Matthews Tom , Murphy Conor , Wilby Robert L.
Published: November 2020

Abstract. Hydroclimatic extremes such as intense rainfall, floods, droughts, heatwaves, and wind/storms have devastating effects each year. One of the key challenges for society is understanding how these extremes are evolving and likely to unfold beyond their historical distributions under the influence of multiple drivers such as changes in climate, land cover, and other human factors. Methods for analysing hydroclimatic extremes have advanced considerably in recent decades. Here we provide a review of the drivers, metrics and methods for the detection, attribution, prediction and projection of nonstationary hydroclimatic extremes. We discuss issues and uncertainty associated with these approaches (e.g arising from insufficient record length, spurious nonstationarities, or incomplete representation of nonstationary sources in modelling frameworks), examine empirical and simulation-based frameworks for analysis of nonstationary extremes, and identify gaps for future research.
Risk assessment in water resources planning under climate change at the Júcar River basin
Authors: Suárez-Almiñana Sara , Solera Abel , Madrigal Jaime , Andreu Joaquín , Paredes-Arquiola Javier
Published: November 2020

Abstract. Climate change and its possible effects on water resources has become an increasingly near threat. Therefore, the study of these impacts in highly regulated systems and those suffering extreme events is essential to deal with them effectively. This study responds to the need for an effective method to integrate climate change projections into water planning and management analysis in order to guide the decision-making, taking into account drought risk assessments. Therefore, this document presents a general and adaptive methodology based on a modeling chain and correction processes, whose main outcomes are the impacts on future natural inflows, a drought risk indicator, and the simulation of future water storage in the water resources system (WRS). This method was applied in the Júcar River basin (JRB) due to its
complexity and the multiannual drought events it suffers recurrently. The
results showed a worrying decrease in future inflows, as well as a high
probability (≈80 %) of being under 50 % of total capacity of
the WRS in the near future. However, the uncertainty of the results was
considerable from the mid-century onwards, indicating that the skill of climate
projections needs to be improved in order to obtain more reliable results.
Consequently, this paper also highlights the difficulties of developing this
type of method, taking partial decisions to adapt them as far as possible
to the basin in an attempt to obtain clearer conclusions on climate change
impact assessments. Despite the high uncertainty, the results of the JRB call for action and the
tool developed can be considered as a feasible and robust method to
facilitate and support decision-making in complex basins for future water
planning and management.
Technical note: Precipitation-phase partitioning at landscape scales to regional scales
Authors: Lynn Elissa , Cuthbertson Aaron , He Minxue , Vasquez Jordi P. , Anderson Michael L. , Coombe Peter , Abatzoglou John T. , Hatchett Benjamin J.
Published: November 2020

Abstract. Water management throughout the western United States largely relies on the partitioning of cool season mountain precipitation into rain and snow, particularly snow as it maximizes available water for warm season use. Recent studies indicate a shift toward increased precipitation falling as rain, which is consistent with a warming climate. An approach is presented to estimate precipitation-phase partitioning across landscapes from 1948 to the present by combining fine-scale gridded precipitation data with
coarse-scale freezing level and precipitation data from an atmospheric
reanalysis. A marriage of these data sets allows for a new approach to
estimate spatial patterns and trends in precipitation partitioning over
elevational and latitudinal gradients in major water supply basins. This
product is used in California as a diagnostic indicator of changing
precipitation phase across mountain watersheds. Results show the largest
increases in precipitation falling as rain during the past 70 years in
lower elevation watersheds located within the climatological rain–snow
transition regions of northern California during spring. Further development of the indicator can inform adaptive water management strategy development and implementation in the face of a changing climate.
Indirect flood impacts and cascade risk across interdependent linear
infrastructures
Authors: Arrighi Chiara , Pregnolato Maria , Castelli Fabio
Published: November 2020

Abstract. Floods are the most frequent and damaging natural threat worldwide. Whereas the assessment of direct impacts is well advanced, the evaluation of indirect impacts is less frequently achieved. Indirect impacts are not due to the physical contact with flood water but result from the reduced performance of infrastructures. Linear critical infrastructures (such as roads and pipes) have an interconnected nature that may lead to failure propagation, so that impacts extend far beyond the inundated areas and/or period. This work presents the risk analysis of two linear infrastructure systems, i.e. the water distribution system (WSS) and the road network system. The evaluation of indirect flood impacts on the two networks is carried out for four flooding scenarios, obtained by a coupled 1D-quasi 2D hydraulic model. Two methods are used for assessing the impacts on the water distribution system and on the road network, a Pressure-Driven Demand network model and a transport network disruption model respectively. The analysis is focused on the identification of: (i) common impact metrics; (ii) vulnerable elements exposed to the flood; (iii) similarities and differences of the methodological aspects for the two networks; (iv) risks due to systemic interdependency. The study presents an application to the metropolitan area of Florence (Italy). When interdependencies are accounted for, results showed that the risk to the WSS in terms of Population Equivalent (PE/year) can be reduced by 71.5 % and 41.8 %, if timely repairs to the WSS stations are accomplished by 60 and 120 minutes respectively; the risk to WSS in terms of pipes length (km/year) reduces by 53.1 % and 15.6 %. The study highlights that resilience is enhanced by system risk-informed planning, which ensures timely interventions on critical infrastructures; however, temporal and spatial scales are difficult to define for indirect impacts and cascade effects. Perspective research could further improve this work by applying a system-risk analysis to multiple urban infrastructures.
Detecting flow features in scarce trajectory data using networks derived from symbolic itineraries: an application to surface drifters in the North Atlantic
Authors: Wichmann David , Kehl Christian , Dijkstra Henk A. , van Sebille Erik
Published: November 2020

Abstract. The basin-wide surface transport of tracers such as heat, nutrients and plastic in the North Atlantic Ocean is organized into large-scale flow structures such as the Western Boundary Current and the Subtropical and Subpolar gyres. Being able to identify these features from drifter data is important for studying tracer dispersal but also for detecting changes in the large-scale surface flow due to climate change. We propose a new and conceptually simple method to detect groups of trajectories with similar dynamical behaviour from drifter data using network theory and normalized cut spectral clustering. Our network is constructed from conditional bin-drifter probability distributions and naturally handles drifter trajectories with data gaps and different lifetimes. The eigenvalue problem of the respective Laplacian can be replaced by a singular value decomposition of a related sparse data matrix. The construction of this matrix scales with O(NM+Nτ), where N is the number of particles, M the number of bins and τ the number of time steps. The concept behind our network construction is rooted in a particle's symbolic itinerary derived from its trajectory and a state space partition, which we incorporate in its most basic form by replacing a particle's itinerary by a probability distribution over symbols. We represent these distributions as the links of a bipartite graph, connecting particles and symbols. We apply our method to the periodically driven double-gyre flow and successfully identify well-known features. Exploiting the duality between particles and symbols defined by the bipartite graph, we demonstrate how a direct low-dimensional coarse definition of the clustering problem can still lead to relatively accurate results for the most dominant structures and resolve features down to scales much below the coarse graining scale. Our method also performs well in detecting structures with incomplete trajectory data, which we demonstrate for the double-gyre flow by randomly removing data points. We finally apply our method to a set of ocean drifter trajectories and present the first network-based clustering of the North Atlantic surface transport based on surface drifters, successfully detecting well-known regions such as the Subpolar and Subtropical gyres, the Western Boundary Current region and the Caribbean Sea.
Simulating optical top-of-atmosphere radiance satellite images over snow-covered rugged terrain
Authors: Lamare Maxim , Dumont Marie , Picard Ghislain , Larue Fanny , Tuzet François , Delcourt Clément , Arnaud Laurent
Published: November 2020

Abstract. The monitoring of snow-covered surfaces on Earth is largely facilitated by the wealth of satellite data available, with increasing spatial
resolution and temporal coverage over the last few years. Yet to date, retrievals of snow physical properties still remain complicated in mountainous
areas, owing to the complex interactions of solar radiation with terrain features such as multiple scattering between slopes, exacerbated over
bright surfaces. Existing physically based models of solar radiation across rough scenes are either too complex and resource-demanding for the
implementation of systematic satellite image processing, not designed for highly reflective surfaces such as snow, or tied to a specific satellite
sensor. This study proposes a new formulation, combining a forward model of solar radiation over rugged terrain with dedicated snow optics into a
flexible multi-sensor tool that bridges a gap in the optical remote sensing of snow-covered surfaces in mountainous regions. The model presented here allows one to perform rapid calculations over large snow-covered areas. Good results are obtained even for extreme cases, such as steep shadowed
slopes or, on the contrary, strongly illuminated sun-facing slopes. Simulations of Sentinel-3 OLCI (Ocean and Land Colour Instrument) scenes performed over a mountainous region in the
French Alps allow us to reduce the bias by up to a factor of 6 in the visible wavelengths compared to methods that account for slope inclination
only. Furthermore, the study underlines the contribution of the individual fluxes to the total top-of-atmosphere radiance, highlighting the
importance of reflected radiation from surrounding slopes which, in midwinter after a recent snowfall (13 February 2018), accounts on average for
7 % of the signal at 400 nm and 16 % at 1020 nm (on 13 February 2018), as well as of coupled diffuse radiation scattered by the
neighbourhood, which contributes to 18 % at 400 nm and 4 % at 1020 nm. Given the importance of these contributions,
accounting for slopes and reflected radiation between terrain features is a requirement for improving the accuracy of satellite retrievals of snow
properties over snow-covered rugged terrain. The forward formulation presented here is the first step towards this goal, paving the way for future
retrievals.
Geothermal heat flux from measured temperature profiles in deep ice boreholes in Antarctica
Authors: Talalay Pavel , Li Yazhou , Augustin Laurent , Clow Gary D. , Hong Jialin , Lefebvre Eric , Markov Alexey , Motoyama Hideaki , Ritz Catherine
Published: November 2020

Abstract. The temperature at the Antarctic Ice Sheet bed and the
temperature gradient in subglacial rocks have been directly measured only a
few times, although extensive thermodynamic modeling has been used to
estimate the geothermal heat flux (GHF) under the ice sheet. During the last
5 decades, deep ice-core drilling projects at six sites – Byrd, WAIS
Divide, Dome C, Kohnen, Dome F, and Vostok – have succeeded in reaching or nearly reaching the bed at inland locations in Antarctica. When temperature
profiles in these boreholes and steady-state heat flow modeling are combined
with estimates of vertical velocity, the heat flow at the ice-sheet base is
translated to a geothermal heat flux of 57.9 ± 6.4 mW m−2 at Dome
C, 78.9 ± 5.0 mW m−2 at Dome F, and 86.9 ± 16.6 mW m−2
at Kohnen, all higher than the predicted values at these sites. This warm
base under the East Antarctic Ice Sheet (EAIS) could be caused by radiogenic
heat effects or hydrothermal circulation not accounted for by the models.
The GHF at the base of the ice sheet at Vostok has a negative value of
−3.6 ± 5.3 mW m−2, indicating that water from Lake Vostok is
freezing onto the ice-sheet base. Correlation analyses between modeled and
measured depth–age scales at the EAIS sites indicate that all of them can be
adequately approximated by a steady-state model. Horizontal velocities and
their variation over ice-age cycles are much greater for the West Antarctic
Ice Sheet than for the interior EAIS sites; a steady-state model cannot
precisely describe the temperature distribution here. Even if the
correlation factors for the best fitting age–depth curve are only moderate
for the West Antarctic sites, the GHF values estimated here of 88.4 ± 7.6 mW m−2 at Byrd and 113.3 ± 16.9 mW m−2 at WAIS Divide can be
used as references before more precise estimates are made on the subject.
The role of grain-size evolution on the rheology of ice: Implications
for reconciling laboratory creep data and the Glen flow law
Authors: Behn Mark D. , Goldsby David L. , Hirth Greg
Published: November 2020

Abstract. Viscous flow in ice is often described by the Glen flow law – a non-Newtonian, power-law relationship between stress and strain-rate with a stress exponent n ~ 3. The Glen law is attributed to grain-size-insensitive dislocation creep; however, laboratory and field studies demonstrate that deformation in ice can be strongly dependent on grain size. This has led to the hypothesis that at sufficiently low stresses, ice flow is controlled by grain boundary sliding, which explicitly incorporates the grain-size dependence of ice rheology. Experimental studies find that neither dislocation creep (n ~ 4) nor grain boundary sliding (n ~ 1.8) have stress exponents that match the value of n ~ 3 in the Glen law. Thus, although the Glen law provides an approximate description of ice flow in glaciers and ice sheets, its functional form is not explained by a single deformation mechanism. Here we seek to understand the origin of the n ~ 3 dependence of the Glen law by using the wattmeter to model grain-size evolution in ice. The wattmeter posits that grain size is controlled by a balance between the mechanical work required for grain growth and dynamic grain size reduction. Using the wattmeter, we calculate grain size evolution in two end-member cases: (1) a 1-D shear zone, and (2) as a function of depth within an ice-sheet. Calculated grain sizes match both laboratory data and ice core observations for the interior of ice sheets. Finally, we show that variations in grain size with deformation conditions result in an effective stress exponent intermediate between grain boundary sliding and dislocation creep, which is consistent with a value of n = 3 ± 0.5 over the range of strain rates found in most natural systems.
WRF-Simulated Low-Level Jets over Iowa: Characterization
and Sensitivity Studies
Authors: Aird Jeanie A. , Barthelmie Rebecca J. , Shepherd Tristan J. , Pryor Sara C.
Published: November 2020

Abstract. Output from high resolution simulations with the Weather Research and Forecasting (WRF) model are analyzed to characterize local low level jets (LLJ) over Iowa. Analyses using a detection algorithm wherein the wind speed above and below the jet maximum must be below 80 % of the jet wind speed within a vertical window of approximately 20 m–530 m a.g.l. indicate the presence of a LLJ in at least one of the 14700 4 km by 4 km grid cells over Iowa on 98 % of nights. Nocturnal LLJ are most frequently associated with stable stratification and low TKE and hence are more frequent during the winter months. The spatiotemporal mean LLJ maximum (jet core) wind speed is 9.55 ms−1 and the mean height is 182 m. Locations of high LLJ frequency and duration across the state are seasonally varying with a mean duration of 3.5 hours. LLJ are most frequent in the topographically complex northwest of the state in winter, and in the flatter northeast of the state in spring. Sensitivity of LLJ characteristics to the: i) LLJ definition and ii) vertical resolution at which the WRF output is sampled are examined. LLJ definitions commonly used in LLJ literature are considered in the first sensitivity analysis. These sensitivity analyses indicate that LLJ characteristics are highly variable with LLJ definition. Further, when the model output is down-sampled to lower vertical resolution, the maximum LLJ wind speed and mean height decrease, but spatial distributions of regions of high frequency and duration are conserved.
The impact of street characteristics on older pedestrians’ perceived safety in Shanghai, China
Authors: Wu Hao , Zhang Zhaoxi , Chen Yong , Jiao Junfeng
Published: November 2020

Land-use patterns and rapid urban sprawl greatly influence older adults’ mobility in China. Older pedestrians’ safety issues are crucial because these people are more frequently injured in traffic accidents. This research aims to investigate what street characteristics influence perceived safety among older pedestrians in Shanghai, China. A mix of research methods containing both quantitative and qualitative analyses were employed. The researchers recruited 68 elderly urban dwellers who each agreed to take a perceived safety survey using 39 simulated streetscape images that contained 12 street characteristics extracted from four sectional zones of streets. Ordinal logit regression was performed to investigate the impact of street characteristics on older pedestrians’ perceived safety. A semi-structured, in-depth interview was conducted with 8 out of the 68 participants. It was found that the street interface type, elevation differences, footpath width, paver directions, isolation facility type, and vehicle traffic all affected pedestrians’ perceived safety after adjusting for individual demographic attributes and the physical limitations of the participants. Understanding the street characteristics related to perceived safety will contribute to making more inclusive and walkable cities.
Real-time urban regional route planning model for connected vehicles based on V2X communication
Authors: Wang Pangwei , Deng Hui , Zhang Juan , Zhang Mingfang
Published: November 2020

Advancement in the novel technology of connected vehicles has presented opportunities and challenges for smart urban transport and land use. To improve the capacity of urban transport and optimize land-use planning, a novel real-time regional route planning model based on vehicle to X communication (V2X) is presented in this paper. First, considering the traffic signal timing and phase information collected by V2X, road section resistance values are calculated dynamically based on real-time vehicular driving data. Second, according to the topology structure of the current regional road network, all predicted routes are listed based on the Dijkstra algorithm. Third, the predicted travel time of each alternative route is calculated, while the predicted route with the least travel time is selected as the optimal route. Finally, we design the test scenario with different traffic saturation levels and collect 150 sets of data to analyze the feasibility of the proposed method. The numerical results have shown that the average travel times calculated by the proposed optimal route are 8.97 seconds, 12.54 seconds, and 21.85 seconds, which are much shorter than the results of traditional navigation routes. This proposed model can be further applied to the whole urban traffic network and contribute to a greater transport and land-use efficiency in the future.
Fear follows form: A study of the relationship between neighborhood type, income and fear of crime at train stations
Authors: Strandbygaard Sofie Kirt , Nielsen Otto Anker , Jones Alan Keith Spence , Grönlund Bo , Jensen Lotte Bjerregaard
Published: November 2020

In pursuing fear-reduction strategies in public transport, the total experience of accessing rail stations should be taken into account. This article correlates passengers’ fear of crime at train stations with neighborhood types and income data within the pedestrian catchment area. The research is based on urban form and income around 84 S-train stations in the Copenhagen metropolitan area and nine years of passenger surveys on fear of crime at these stations. The study reveals a significant positive correlation between low income and fear of crime; the lower the income in an urban area, the more unsafe passengers feel at the station. However, when controlling for the relationship between income, safety and neighborhood type, stations in neighborhoods with urban form associated with low incomes have the lowest ratings of safety. The research indicates that train passengers’ sense of security is connected to neighborhood type and the city’s planning characteristics. This is an important finding for urban designers and planners working on the integration of public transport and station design in urban areas.
S-Methylene linkage comprising 1,3,4-oxadiazoles: synthesis, reaction optimization and in vitro anti-microbial potential
Authors: Dhuda Gautam M. , Kapadiya Khushal M. , Ladwa Paresh D. , Modha Jayesh J.
Published: November 2020

To generate a new class of scaffolds with amended anti-microbial potency, synthesis and in vitro biological evaluation of a series of 2-((5-(3-nitrophenyl)-1,3,4-oxadiazol-2-yl)methylthio)-5-substitutedphenyl-1,3,4-oxadiazole (5a-5o) having S-Methylene linkage between the two 1,3,4-diisoxazole rings is reported. Anti-microbial properties of the entire compounds were investigated in a broad panel of some selected gram-positive bacterial strains, gram-negative bacterial strain, and fungal strains using the broth microdilution method. The results were dominant on –Cl and –NO2 functionality than the used standard drug.
Synthetic and therapeutic potential of 4-thiazolidinone and its analogs
Authors: Agrawal Neetu
Published: November 2020

Past researches on 4-thiazolidinone nucleus have revealed the prominent potential of derivatives containing this nucleus to be developed as a potent therapeutic agent. Because of these biological activities, their structure-activity relationship has created an interest for medicinal chemists leading to the discovery of a number of lead molecules. This review highlights the routes for its synthesis and summarizes the past and recent studies on its biological activities to guide the medicinal chemists working on this nucleus in the development of clinically viable drugs.
Comparison of synthetic routes for fully substituted (1H-1,2,3-triazol-4-yl)acetic acids
Authors: Pokhodylo Nazariy , Savka Roman , Obushak Mykola
Published: November 2020

The new fully substituted (1H-1,2,3-triazol-4-yl)acetic acids were synthesized from available precursors (1H-1,2,3-triazol-4-yl)ethanones and 1Н-1,2,3-triazole-4-carboxylic acids, which are easily prepared by the Dimroth reaction from azides and 1,3-dicarbonyl compounds. The practical methods of homologization (the Arndt–Eistert reaction and homologization as a result of nucleophilic substitution by cyanide anion) and the Willgerodt-Kindler reaction were compared. The Willgerodt-Kindler method starting from (5-methyl-1H-1,2,3-triazol-4-yl)ethanones was selected as the most convenient method for the synthesis of 2-(1-aryl-5-methyl-1H-1,2,3-triazol-4-yl)acetic acids, which are promising building blocks for drug discovery. Additionally, (1H-1,2,3-triazol-4-yl)ethanones were studied for the synthesis of alcohols, amines and in the Johnson–Corey–Chaykovsky reaction.
Silver and gold nanoparticles as an integral part of nanooncology: current state of the problem
Authors: Osadchuk M.A. , Kireeva N.V. , Korzhenkov N.P. , Trushi M.V.
Published: November 2020

Gold and silver nanoparticles are easily synthesized and the most effective nanostructures in clinical practice. Their optical properties, ease of synthesis, colloidal stability and the ability to form any surface for easier conjugation with biological particles, the ability to individual multiple use, make them especially important in oncology. Gold and silver nanoparticles are capable of providing targeted drug delivery, which depends on the photothermal, photodynamic, and antiangiogenic properties of the metal. Due to their exceptional properties, these nanoparticles are considered as a potential tool for the diagnosis of various types of cancer and drug delivery. The non-toxic and non-immunogenic nature of gold and silver nanoparticles, as well as their high permeability and retention effect, provide additional advantages, allowing drugs to easily penetrate and accumulate at tumor sites. The effectiveness of precious metal nanoparticles as radiosensitizers, dose enhancers and contrast agents is gaining increasing recognition. An important problem associated with the use of biogenic metal nanoparticles is the study of their genotoxicity, since they play an important role in the initiation and progression of abnormalities, including genetic ones.
Hypertensive Patients Knowledge, Attitude and Practice for Stroke Prevention in Uttarakhand, India
Authors: Sinha Roshni , Verma Poonam , Rohilla Kusum K , Kalyani C Vasantha
Published: November 2020

Introduction: Worldwide, Stroke becomes a public health problem. In India, reports indicating towards its emerging epidemic in near future. Hypertensive disease is considered as predisposing factor for Stroke. The present study aimed to assess knowledge, attitude and practice of hypertensive patients for stroke prevention in Uttarakhand, India.

Methodology: The present study was a cross sectional study conducted on 243 hypertensive patients who were visiting outpatient department of All India Institute of Medical sciences (AIIMS), Rishikesh by using purposively sampling technique. Structured questionnaire of knowledge, attitude and practice were used to collect data from participants of the study. Data analysis was done by using SPSS version 23.0 statistical package.

Results: Majority participants were of more than 60 years age, male, illiterate and no family history of hypertension. Most of participants were taking their regular treatment for hypertension. 185 (76%) hypertensive patients were having poor knowledge for stroke prevention. 215 (88%) participants had neutral attitude towards stroke prevention strategies whereas majority (64%) were following good practices.

Conclusion: Findings suggested that policy makers should focus on health education of high risk group for stroke and also empower them with knowledge to control rising curve of stroke globally.
Assessment of Nicotine Dependence among Adult Tobacco Users in Selected Urban Population of Ahmedabad City
Authors: Mall Anjali , Vyas Sheetal
Published: November 2020

Background: Tobacco consumption is considered as a major public health problem in India.  However, nicotine dependency is an area which has not been given much importance. The FTND score is considered as an easy tool to assess the dependence through physiological and behavioural symptoms.
Aim and Objectives: To assess the nicotine dependence of the tobacco users in urban slums of Ahmedabad city.
Methodology: Nicotine dependence among tobacco users (18-60 years) was studied by means of six -item. (Fagerstrom Test for Nicotine Dependence) in a community based interventional cluster randomized trial which was conducted through house to house survey from 20 clusters (slums) of Ahmedabad district.
Result: Among 1968 people surveyed, a total of 400 subjects in intervention and control arm were interviewed. The prevalence of tobacco use was 20.3%. 23 % of the tobacco users had high to very high dependence. The overall FTND score was 4.5 and score for smoking was high 5.4 (2.2).
Conclusion: A medium level of dependence was observed among the tobacco users in the current study. Tobacco intervention study can be more effective and productive if a baseline assessment of nicotine dependence is measured before any intervention.
De NOW en bedrijfseconomisch ontslag: de spagaat van een werkgever die loonkostensubsidie aanvraagt, maar tegelijkertijd moet reorganiseren
Authors: Terpstra Juno
Published: November 2020

De NOW en bedrijfseconomisch ontslag: de spagaat van een werkgever die loonkostensubsidie aanvraagt, maar zich tegelijkertijd genoodzaakt ziet om te reorganiseren

De economische gevolgen van de coronapandemie zullen langer aanhouden dan aanvankelijk werd gedacht. Bedrijven kunnen een beroep doen op tijdelijke steunmaatregelen van de overheid zoals de NOW, maar moeten tegelijkertijd structurele maatregelen nemen om ook op de lange termijn te kunnen overleven. Werkgevers die loonkostensubsidie aanvragen onder de NOW moeten echter rekening houden met de beperkingen die de NOW stelt aan bedrijfseconomische ontslagen. Dit artikel bespreekt de ontslagverplichtingen uit de NOW en de gevolgen die deze kunnen hebben op de hoogte van de subsidie. Deze verplichtingen dwingen werkgevers daarop te anticiperen en vooraf een weloverwogen keuze te maken.
De AVG en ontslag: twee jaar na inwerkingtreding AVG
Authors: Dorenbos Karolina
Published: November 2020

De AVG en ontslag: twee jaar na inwerkingtreding AVG

Twee jaar na inwerkingtreding van de Algemene verordening gegevensbescherming zet de auteur in dit artikel een aantal recente ontwikkelingen op het gebied van gegevensverwerking en -bescherming op de werkvloer uiteen. In het eerste deel van het artikel gaat zij in op de meer institutionele aspecten waaronder de evaluatie van de (U)AVG. De auteur ziet ingrijpende ontwikkelingen op het gebied van wetgeving en toezicht zoals de voorgenomen wetgeving over het gebruik van alcohol- en drugstesten op de werkvloer en de ontwikkelingen op het gebied van biometrie waaronder een hoge boete van Autoriteit Persoonsgegevens voor het gebruik van de vingerscan bij toegangscontrole. In deel 2 van dit artikel zal de huidige stand van de rechtspraak worden afgezet tegen de strengere normen uit de AVG.
Opvolgende arbeidsovereenkomsten en misbruik: van Campina tot en met Taxi Dorenbos
Authors: Palm Steven
Published: November 2020

Opvolgende arbeidsovereenkomsten en misbruik: van Campina tot en met Taxi Dorenbos

De centrale vraag in dit artikel is: welke gezichtspunten biedt de jurisprudentie van de Hoge Raad voor de beoordeling of het gebruik van de wettelijke mogelijkheden tot het sluiten van opvolgende arbeidsovereenkomsten voor bepaalde tijd in een concreet geval moet worden aangemerkt als misbruik en hoe verhouden deze gezichtspunten zich tot later ingevoerde wetgeving alsmede de opvattingen van de regering over het gebruik van opvolgende arbeidsovereenkomsten voor bepaalde tijd?
Kroniek ontslaggronden: c-, d-, f-, h- en i-grond
Authors: Kruit Pascal , Kersten Ilse
Published: November 2020

Kroniek ontslaggronden: c-, d-, f-, h-, en i-grond

In deze kroniek wordt een analyse gegeven van de gepubliceerde rechtspraak over de ontslaggronden c, d, f, h en i in de eerste vijf jaar na de inwerkingtreding van de Wet werk en zekerheid
Application of the life cycle cost estimation method in transport infrastructure managing
Authors: Gobis Anna , Jamroz Kazimierz , Jeliński Łukasz
Published: November 2020

The transport infrastructure management should be in line with sustainable development. Actions and activities that combine the environmental, social, and infrastructure expenditures optimally should be undertaken. The article presents a concept of life-cycle thinking that resolves these problems. The life cycle cost estimation method is a practical tool for managing transport infrastructure. The LCC analysis mustn’t generate more work than the benefits of it. Therefore appropriate assumptions should be made in constructing the method. The method assumes basic assumptions, taking into account the extensive scope of the research problem: transport infrastructure. The result of this article is a proposed mathematical model for estimating life-cycle costs. In the end, the practical use of the proposed methodology for determining the cost of the horizontal marking is provided.