bluuebunny/crossref_metadata_2025 huggingface dataset:
Palaeoclimatological interpretation of loess-paleosol sequences using log-ratio transformation of granulometric and geochemical data; Czech Republic
Authors: Šimíček Daniel , Bábek Ondřej , Hron Karel , Pavlů Ivana
Published: March 2021

The loess-paleosol sequences (LPS) are an important source of proxy data documenting climatic fluctuations in the Quaternary. Understanding the relationship between the grain size distribution and the geochemistry is crucial for the reliable palaeoclimatological and palaeoenvironmental interpretation of the LPS. For this purpose, the large granulometric (389 samples) and geochemical datasets (542 samples measured using EDXRF spectrometer) were acquired at four LPS in Moravia (eastern part of Czech Rep.). Czech loess represent an important part of the European loess belt, because they characterize region with alternating influence of the oceanic and continental macroclimate, modified by close contact to the front of both continental and alpine glaciation during glacial periods. Moreover, a very diverse geology is characteristic for the source area (the Bohemian Massif) of Czech loess. Therefore, distinguishing of provenance and transporting and post-deposition processes effects on the formation of the Czech LPS requires finding new approaches of statistical evaluation of datasets. Centered log-ratio (clr) transformation and scalar-on-function regression allow finding a relationship between the geochemical composition and the grain-size distribution of loess and soils. Centered log-ratio (clr) transformation was applied to the key elemental proxies of grain size, provenance and weathering and their spatial and stratigraphic distribution. Nearly all LPS samples are characteristic by bimodal grain-size distribution with the main modes corresponding to medium/coarse silt and clay fractions. The scalar-on-function regression shows that the grain-size control of the distribution of Al, Si, K, Ca, Fe, Rb, Sr and Zr is highly site-specific. The provenance signal is recorded especially in coarser-grained fractions transported for short distance. The content of the authigenic phyllosilicates in clay fraction, the alteration of feldspars and micas, low contents of K, and high values of Rb/Sr and Sr/Ca ratios reflect the intensity of weathering, which is highest in the weakly developed brown paleosols. The precipitation rates are suggested the most important microclimatic factor, which affect the intensity of loessification and pedogenic processes forming the Czech LPS.

This research was supported by the Czech Science Foundation (GAČR) research project 19-017685.
Multi-decadal tropical-Arctic atmospheric teleconnections and their influences on Greenland Ice Sheet melt
Authors: Topal Daniel , Ding Qinghua , Hatvani István Gábor , Ballinger Thomas J
Published: March 2021

Despite the contribution of the Greenland Ice Sheet (GrIS) to global sea level rise, the lack of a complete understanding of its driving mechanisms largely constrains future model projections. Brief observational records limit model development efforts, however, the assimilation of paleoclimatic proxy data in climate models provides new opportunities to place recent climate changes in and around the Arctic in the context of long-term high-latitude variability. Building off of previous work, we investigate the relative role of internal atmospheric variability in modulating GrIS surface mass balance (SMB) using the newly available Ensemble Kalman Fitting Paleo-Reanalysis (EKF400) version 2, with monthly resolution for the period 1602-2003 AD, and the Last Millennium Reanalysis (LMR) version 2, which has an annual resolution from 0-2000 AD. We apply maximum covariance and empirical orthogonal function analyses on these two datasets to reveal co-varying patterns of Arctic upper-tropospheric changes and the GrIS SMB over centennial and millennial timescales with a special focus on remote tropical drivers of this local coupling. In light of these tropical-Arctic linkages in shaping GrIS conditions over the past two millennia, the application of proxy-assimilated model experiments provides deeper insights into the formation of such atmospheric dynamical connections that may impact GrIS SMB in the future.

I.G.H is supported by the Ministry of Human Capacties (NTP-NFTÖ-20-B-0043).
Accurate continuous observations of carbon dioxide and methane dry mole fractions in the arctic atmosphere near the Dikson settlement, Siberia
Authors: Panov Alexey , Prokushkin Anatoly , Lavrič Jošt , Kübler Karl , Korets Mikhail , Urban Anastasiya , Sidenko Nikita , Zrazhevskaya Galina , Bondar Mikhail , Heimann Martin
Published: March 2021

Measurements of the atmospheric sources and sinks of carbon dioxide (CO2) and methane (CH4) in the pan-Arctic domain are extremely sparse that limits our knowledge of carbon cycling over this dramatically sensitive environment and making predictions about a fate of carbon conserved in currently frozen ground. Especially critical are the gaps in the arctic latitudes of Siberia, covered by the vast permafrost underlain tundra, where only few continuous atmospheric observation stations are currently operational.

We present the first two years of accurate continuous observations of atmospheric CO2 and CH4 dry mole fractions at the new atmospheric carbon observation station located near the Dikson settlement (73.33° N, 80.34° E) on the seashore of the western part of the Taimyr Peninsula in Siberia. Data quality control of trace gas measurements is achieved by regular calibrations against WMO-traceable reference gases from pressurized dry air tanks filled at the Max Planck Institute for Biogeochemistry (Jena, Germany). Associated meteorological variables permit evaluation of the climate variability of the local environment and provide a background for screening and interpreting the greenhouse gases (GHG) data records. Here we summarize the scientific rationale of the new site, give technical details of the instrumental setup, analyse the local environments and present CO2 and CH4 fluctuations in the arctic atmosphere. Along with the temporal variability of GHG’s, we provide an overview of the angular distribution of detected GHG signals in the region and their input to the atmospheric fluctuations on the measurement site. Observation records deal with the daytime mixed layer and may be considered as representative throughout the vast area (~500–1000 km), and cover the period from September 2018 to September 2020.

The reported study was funded by Russian Foundation for Basic Research, Krasnoyarsk Territory and Krasnoyarsk Regional Fund of Science, project number 20-45-242908, RFBR project 18-05-60203 and by the Max Planck Society (Germany)
Comparing slope stability analysis using limit equilibrium and finite elements simulations of deep-seated landslides along the western margin of the Main Ethiopian Rift
Authors: Mebrahtu Tesfay Kiros , Heinze Thomas , Wohnlich Stefan
Published: March 2021

Landslides and ground failures are among the common geo-environmental hazards in many of the tectonically active hilly and mountainous terrains of Ethiopia, such as in the western margin of the Main Ethiopian Rift in Debre Sina area. Besides the geological preconditioning, bi-modal monsoon and seismic events in the tectonically highly active region are usually suspected triggers. In order to minimize the damage caused by the slope failure events, a detailed investigation of landslide-prone areas using numerical modelling plays a crucial role. The aim of this study is to assess the stability of slopes, to understand the relevant failure mechanisms, and to evaluate and compare safety factors calculated by the different available numerical methods. The stability was assessed for slopes of complex geometry and heterogeneous material using the limit equilibrium method and the shear strength reduction method based on finite elements. Furthermore, numerical analysis was done under static and pseudo-static loading using the horizontal seismic coefficient to model their stability during a seismic event. The slope stability analysis indicates that the studied slopes are unstable, and any small scale disturbance will further reduce the factor of safety and probably causing failure. The critical strength reduction factors from the finite element method are significantly lower than the factor of safety from the limit equilibrium method in all studied scenarios, such as Bishop, Janbu Simplified, Spencer and Morgenstern-Price. The difference is especially evident for heterogeneous slopes with joints, which often are initiation points for the failure planes. The simulations show that slope stability of landslide prone hills in the study area strongly depends on the saturation conditions and the seismic load. The studied slopes are initially close to failure and increased pore-pressure or seismic load are very likely triggers.
Site-level simulations of measurable soil fractions with the Millennial V2 soil model
Authors: Abramoff Rose , Guenet Bertrand , Zhang Haicheng , Georgiou Katerina , Xu Xiaofeng , Viscarra-Rossel Raphael , Yuan Wenping , Ciais Philippe
Published: March 2021

Soil carbon (C) models are used to predict C sequestration responses to climate and land use change. Yet, the soil models embedded in Earth system models typically do not represent processes that reflect our current understanding of soil C cycling, such as microbial decomposition, mineral association, and aggregation. Rather, they rely on conceptual pools with turnover times that are fit to bulk C stocks and/or fluxes. As measurements of soil fractions become increasingly available, it is necessary for soil C models to represent these measurable quantities so that model processes can be evaluated more accurately. Here we present Version 2 (V2) of the Millennial model, a soil model developed in 2018 to simulate C pools that can be measured by extraction or fractionation, including particulate organic C, mineral-associated organic C, aggregate C, microbial biomass, and dissolved organic C. Model processes have been updated to reflect the current understanding of mineral-association, temperature sensitivity and reaction kinetics, and different model structures were tested within an open-source framework. We evaluated the ability of Millennial V2 to simulate total soil organic C (SOC), as well as the mineral-associated and particulate fractions, using three independent data sets of soil fractionation measurements spanning a range of climate and geochemistry in Australia (N=495), Europe (N=176), and across the globe (N=716). Considering RMSE and AIC as indices of model performance, site-level evaluations show that Millennial V2 predicts soil organic carbon content better than the widely-used Century model, despite an increase in process complexity and number of parameters. Millennial V2 also reproduces between-site variation in SOC across gradients of climate, plant productivity, and soil type. By including the additional constraints of measured soil fractions, we can predict site-level mean residence times similar to a global distribution of mean residence times measured using SOC/respiration rate under an assumption of steady state. The Millennial V2 model updates the conceptual Century model pools and processes and represents our current understanding of the roles that microbial activity, mineral association and aggregation play in soil C sequestration.
2D numerical simulation of shallow water and bedload transport in channel confluences by considering the non-hydrostatic pressure
Authors: Balouchi Behnam , Rüther Nils , Shafaei Bejestan Mahmood , Valerie Anne Schwarzwälder Kordula , Bihs Hans
Published: March 2021

Channel confluence is one of the important sections of channel networks which is also common encountered in nature. Six different zones exist at a channel confluence: 1) stagnation zone, 2) flow deflection zone, 3) flow separation zone, 4) maximum velocity zone, 5) flow recovery zone and 6) shear layers between combining flows zone. Due to the complexity of flow pattern at channel confluence, this location is always interesting among researchers. Although there are a number of studies on the flow and sediment pattern at confluences, there are still some gaps to be studied. Hence, a calibrated numerical model should be a good tool for evaluating the various effective parameters on flow and sediment patterns. The numerical 2D shallow-water model used in this paper is SFLOW which was developed by NTNU. Besides, the model calibration part of the current study is done by using a set of data from laboratory experiments.

This study attempt to simulate bed changes at channel confluences with a 2D shallow-water modeling under non-hydrostatic pressure, and show the applicability of the SFLOW model for this complex flow pattern. SFLOW solving the depth-averaged Navier-Stokes equations which is equipped with cutting-edge solvers. Besides, SFLOW modeled turbulency with depth-averaged two-equation RANS. In comparison with other codes, one of the interesting features of SFLOW is solving the non-hydrostatic pressure besides of hydrostatic part. This leads to a more realistic representation of the complex flow and sediment patterns of channel confluences, and consider less computational power than full 3D models.
Comparison of permafrost mean annual ground temperature derived from two different satellite-based schemes: land surface temperature based (ESA CCI+ Permafrost) versus surface status (Metop ASCAT)
Authors: Jakober Dan , Bergstedt Helena , Kroisleitner Christine , Bartsch Annett
Published: March 2021

Different approaches exist for a satellite-based estimation of mean annual ground temperature (MAGT). Landsurface temperature can be ingested by transient models. Surface status information (frozen/unfrozen days) has been shown to be applicable for the estimation of ground temperature as well. Such approaches are based on an empirically defined relationship. Both approaches have been evaluated with in situ bore hole measurements, but not yet compared with each other.

A comparison between yearly arctic mean temperatures, derived from the advanced scatterometer (ASCAT) and data from ESA’s CCI+ Permafrost project was carried out. The used ASCAT record is available from 2008 (first full year) onwards while the latest CCI+ Permafrost data is available from 1997 to 2018. The ASCAT data was recorded by satellites whose measurements are only intermittently available as one flyover over the whole arctic north of 60°N takes two days on average. To fill in the missing values exponentially weighted moving averages (EWMA) were used. From the number of frozen days an expected average temperature was derived based on Kroisleitner et al. (2018).

The CCI+ Permafrost data incorporates modelled MAGT for depths between the surface down to a depth of 10 meters. These data points were extracted from the raster files (~1km resolution) and averaged over polygons representing an approximation of the ASCAT grid (footprint approximation). Single polygon areas range from 150-160 km². Only footprints for which data is available in both records (and thus permafrost presence) have been eventually compared.

The CCI+ Permafrost data shows an average surface temperature of -1.42 °C for the areas analyzed between 2008 and 2018 while the statistically padded ASCAT data suggests a mean temperature of -1.18 °C over the same time period. The ASCAT retrieval corresponds to a general MAGT whereas CCI+ Permafrost values are available for certain depths. Water fraction within ASCAT footprint also affect the quality of the derivation of frozen days. New calibration considering certain depths and water fraction is suggested.
Fire-related forest properties observed using Landsat and radar data
Authors: Ningthoujam Ramesh , Prestes Nayane Cristina Candida dos Santos , Feldpausch Ted R. , Wooster Martin , Harrison Sandy P. , Prentice Iain Colin
Published: March 2021

Fire is an important cause of disturbance in terrestrial ecosystems and can have a major impact on biodiversity. Long-term forest plot monitoring in Mato Grosso state (Brazil) indicates lowest species diversity in plots that have been burned multiple times and increasing species richness with time since the last fire. Furthermore, there is a strong positive relationship between species richness and basal area in unburnt and once-burnt plots, especially in the large tree stratum. We used high-resolution Landsat and PALSAR data at varying spatio-temporal (single and bi-temporal) scales to (a) assess Vegetation Indices sensitive to varying fire severity for different tropical forest species; (b) quantify fire severity and basal area/ biomass changes (1999, 2006, 2010, 2013); and (c) quantify the sensitivity of L-band backscatter to fuel load, moisture content and basal area/ biomass dynamics.
Preliminary monthly gravity field models from kinematic orbits of SWARM Satellites
Authors: Zhang Xingfu , Chen Qiujie , Shen Yunzhong
Published: March 2021

      Although the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE FO) satellite missions play an important role in monitoring global mass changes within the Earth system, there is a data gap of about one year spanning July 2017 to May 2018, which leads to discontinuous gravity observations for monitoring global mass changes. As an alternative mission, the SWARM satellites can provide gravity observations to close this data gap. In this paper, we are dedicated to developing alternative monthly time-variable gravity field solutions from SWARM data. Using kinematic orbits of SWARM from ITSG for the period January 2015 to September 2020, we have generated a preliminary time series of monthly gravity field models named Tongji-Swarm2019 up to degree and order 60. The comparisons between Tongji-Swarm2019 and GRACE/GRACE-FO monthly solutions show that Tongji-Swarm2019 solutions agree with GRACE/GRACE-FO models in terms of large-scale mass change signals over amazon, Greenland and other regions. We can conclude that Tongji-Swarm2019 monthly gravity field models are able to close the gap between GRACE and GRACE FO.
Postprocessing wind forecasts with deep learning in complex terrain
Authors: Nerini Daniele , Bhend Jonas , Spirig Christoph , Moret Lionel , Liniger Mark
Published: March 2021

To improve and automate the quality of weather forecasts to the public, MeteoSwiss is redesigning its statistical postprocessing suite. The effort aims at producing calibrated probabilistic predictions to any arbitrary point in space and up to a 15-day lead time, by seamlessly integrating multiple numerical weather prediction models into a unique consensus forecast.

For hourly wind forecasts (mean, gust, and direction), the task is formulated as a regression problem in a supervised machine learning framework, where station measurements are used as labels, and co-located NWP forecasts as features. To improve the estimates at ungauged locations, additional static topographical features are derived from a 50m digital elevation model. The probabilistic component is included by training the neural network not to produce a deterministic prediction, but the parameters of a conditional probability function. To this end, the Continuous Ranked Probability Score (CRPS) is used as a loss function.

The dataset includes a range of surface parameters at hourly resolution produced by the operational forecasts from three NWP models (the deterministic COSMO-1 model, at 1 km horizontal resolution; the 21-member COSMO-E, 2 km; and the 51-member ECMWF IFS ENS at about 18 km). The data cover the whole of Switzerland over a period spanning more than four years (mid 2016 to end of 2020). Wind measurements from over 500 surface weather stations are included as reference dataset. The study uses a train-validation-test split in both space and time to assess the ability of the postprocessing model to generalize to unseen locations and times.

The results indicate that, despite the challenging nature of the problem, the postprocessing model can improve over the baseline NWP forecasts in terms of CRPS on the test set. In particular, the model is effectively correcting for biases relating to altitude error and other misrepresentations in the NWP topography. The results show that it is feasible to downscale numerical predictions to a substantially higher spatial resolution. Moreover, the conditional probabilities shows consistent improvements in terms of calibration, although it remains a significant portions of undetected peak events (positive outliers), possibly to be related to unpredictable phenomena (e.g., thunderstorm gusts). Finally, first results seem to suggest that the gain in prediction skill is mainly driven by a better statistical reliability rather than higher statistical resolution.
Towards an updated, enhanced regional gravity field solution for Antarctica
Authors: Scheinert Mirko , Zingerle Philipp , Schaller Theresa , Pail Roland , Willberg Martin
Published: March 2021

In the frame of the IAG Subcommission 2.4f “Gravity and Geoid in Antarctica” (AntGG) a first Antarctic-wide grid of ground-based gravity anomalies was released in 2016 (Scheinert et al. 2016). That data set was provided with a grid space of 10 km and covered about 73% of the Antarctic continent. Since then a considerably amount of new data has been made available, mainly collected by means of airborne gravimetry. Regions which were formerly void of any terrestrial gravity observations and have now been surveyed include especially the polar data gap originating from GOCE satellite gravimetry. Thus, it is timely to come up with an updated and enhanced regional gravity field solution for Antarctica. For this, we aim to improve further aspects in comparison to the AntGG 2016 solution: The grid spacing will be enhanced to 5 km. Instead of providing gravity anomalies only for parts of Antarctica, now the entire continent should be covered. In addition to the gravity anomaly also a regional geoid solution should be provided along with further desirable functionals (e.g. gravity anomaly vs. disturbance, different height levels).

We will discuss the expanded AntGG data base which now includes terrestrial gravity data from Antarctic surveys conducted over the past 40 years. The methodology applied in the analysis is based on the remove-compute-restore technique. Here we utilize the newly developed combined spherical-harmonic gravity field model SATOP1 (Zingerle et al. 2019) which is based on the global satellite-only model GOCO05s and the high-resolution topographic model EARTH2014. We will demonstrate the feasibility to adequately reduce the original gravity data and, thus, to also cross-validate and evaluate the accuracy of the data especially where different data set overlap. For the compute step the recently developed partition-enhanced least-squares collocation (PE-LSC) has been used (Zingerle et al. 2021, in review; cf. the contribution of Zingerle et al. in the same session). This method allows to treat all data available in Antarctica in one single computation step in an efficient and fast way. Thus, it becomes feasible to iterate the computations within short time once any input data or parameters are changed, and to easily predict the desirable functionals also in regions void of terrestrial measurements as well as at any height level (e.g. gravity anomalies at the surface or gravity disturbances at constant height).

We will discuss the results and give an outlook on the data products which shall be finally provided to present the new regional gravity field solution for Antarctica. Furthermore, implications for further applications will be discussed e.g. with respect to geophysical modelling of the Earth’s interior (cf. the contribution of Schaller et al. in session G4.3).
Potential of accumulated AROME-Arctic parameterisation tendency for stochastic parameterisation perturbation patterns
Authors: Sodemann Harald , Kähnert Marvin , Valkonen Teresa Maaria , Ekrem Petter , Frogner Inger-Lise
Published: March 2021

Stochastic parameterisations are an important way to represent uncertainty in the deterministic forecasting models underlying ensemble prediction systems. In many of the currently used stochastic parameterisation approaches, random generators produce correlation patterns that induce spatially and temporally coherent perturbations to the parameterisation parameters or tendencies. The patterns that are currently used in the Harmonie ensemble prediction system are therefore unrelated to the atmospheric flow or weather situation. Here we investigate the potential of replacing such random patterns by accumulated tendency fields from parameterized physical processes in the model. The rationale hereby is that by perturbing the parameterisations with a field that reflects where parameterisations are most active, rather than a random pattern, the model obtains a more targeted increase in the degrees-of-freedom to represent forecasting uncertainty.

As an initial test case, we consider a large cold-air outbreak during 23-25 Dec 2015 that affected large parts of Scandinavia. During that time period, strong heat fluxes persisted near the ice edge, while widespread shallow convection dominated in the center of the model domain. For diagnosing the perturbation fields, we utilise an implementation of individual tendency diagnostics implemented in AROME-Arctic within the ALERTNESS project. Total physical tendencies for the horizontal wind components, for air temperature and humidity are accumulated with a time filtering throughout the 66 h forecast period.

The accumulated tendencies from all parameterisations for the different variables show overlapping and differing centers of activity. Wind parameterisations are active near the ice edge, and with smaller scale variability over land areas, in particular at lower model levels. Temperature tendency patterns show activity that is more confined to the ice edge, and a narrow coastal stripe along Northern Scandinavia. These first results show that the approach provides spatially coherent patterns of parameterisation activity, which are meaningfully related to the dominating weather situation. Based on sensitivity tests of cloud parameterisation parameters in a single-column version, we outline the next steps in the path towards diagnostic perturbation patterns for stochastically perturbed perturbations in the Harmonie EPS system.
New thermal constraints for the Anatolian lithosphere from Curie depth point and Pn tomography
Authors: Ozbakir Ali Deger , Karabulut Hayrullah
Published: March 2021

Continental deformation can be described in two end-member approaches: block (or microplate) and continuum models. The first considers a strong lithosphere with deformation localized in fault zones. For the latter, however, the lithosphere is weak and deforms as a thin viscous sheet. The Anatolia – Aegean domain represents both continuum and plate-like deformation. Furthermore, recent modeling studies suggest a dynamic support mechanism of the Anatolian plateaus, with dynamic topography estimates ranging from 1 to 3 km for various crustal models and geodynamic scenarios, although the gravity and crustal thickness data support predominant Airy isostasy. The solution to both intricacies relies on the thermal structure of the crust and the lithosphere. Available thermal considerations stem from either the uppermost mantle velocity structure or thermal modeling with assumptions on radiogenic heat production and boundary conditions. Yet, homogeneous and independent constraints on the lithospheric structure are scarce. We aim to contribute to this knowledge gap by providing Curie Point Depths (CPDs), which corresponds to the depth at which rock-forming minerals lose their magnetization at the Curie temperature, ~580 oC.

Resolution of deep magnetic sources requires spectral methods with large windows, which reduce the CPD resolution. Moving & overlapping smaller windows have been used in order to increase the resolution, but these introduce spectral leakage and bias. In previous studies, subjective wavenumber ranges of the magnetic anomaly spectra were used, often combined with wrong scaling factors between map units and the equations. This resulted in generally erroneous CPD estimates. Furthermore, CPD uncertainties have often been unquantified for the study area. We use a wavelet transform method, which overcomes the artifacts due to segmentation of magnetic signal to finite windows, results in higher spatial resolution as well as enabling uncertainty estimation. We used as large an area as possible for constraining the edge effects away from the study area. The resultant CPD map spatially correlates well with low Pn velocity areas, locations of volcanoes, and thermal springs.
Air quality at open-cast coal mining regions at Hunter Valley, Australia and Ramagundam, India
Authors: Kamath Harsh , Chauhan Chanchal , Mishra Sameer , Ahmed Aariz , Srikanth Raman
Published: March 2021

The upper Hunter Valley region in New South Wales (NSW), Australia has several open-cast coal mines, which supply coal to two large thermal power plants (TPPs) in the area, beside the export market. Long-term Particulate Matter (PM) pollutants and meteorological measurements are recorded by a network of 13 NSW government-owned continuous monitoring stations in the upper Hunter Valley region. The Ramagundam area in the state of Telangana, India has similar pollution source characteristics (coal mines and TPPs), but PM pollutant measurements are largely carried out with manual monitoring stations at 24-hour intervals, not more than twice a week. As the coal and overburden excavation from open-cast coal mines and stack emissions from TPPs lead to local PM pollution, we have used MODIS-MAIAC Aerosol Optical Depth (AOD) at 550 nm and Normalized Difference Vegetation Index (NDVI) along with the local meteorological data such as ambient temperature, relative humidity, wind speed and direction to model PM10 and PM2.5 at the upper Hunter Valley and Ramagundam regions. Our model can explain about 60% of variation in PM10 (p-value < 0.0001), while a similar model is able to explain about 75% of the variation in the PM2.5 (p-value < 0.0001). We will extend our model results from Hunter Valley to Ramagundam area and comment on the potential of using geospatial products such as AOD as a proxy to ground-based pollution measurements in developing countries such as India, where pollution data is scarce.
Modeling of Lagrangian particles in turbulence boundary layer considering attached eddies: particle trajectories and concentration profiles
Authors: Huang Yu-Ying , Tsai Christina W.
Published: March 2021

     Sediment particles in flow not only follow the mean drift, but also diffuse randomly due to turbulence. Owing to this property, Lagrangian particle trajectory is regarded as a stochastic process in this study. The proposed model based on Lagrangian methods will combine physical mechanisms and stochastic methods to simulate the particle motion, and uses the Brownian motion to describe the diffusion affected by turbulence. In turbulence boundary layer, there are eddies with different length and velocity scales. Eddies affect the motion of a particle, like the occurrences of ejection and sweep events. Among others, those extended to the wall, named attached eddies, are primarily responsible for most of the turbulent kinetic energy and Reynolds shear stresses. Perry & Marušić (1995) further divided the attached eddies into two types, those directly attached to the wall are called Type-A eddies while others not directly attached to the wall in the wake region are called Type-B eddies. The scales of Type-B eddies are affected by the distance away from the wall. Therefore, this study will combine the above-mentioned theory and the stochastic diffusion particle tracking model (SD-PTM) to simulate the Lagrangian sediment particles in turbulence boundary layer considering the effects of attached eddies.
     The SD-PTM which has been built on the Lagrangian scheme and derived from the Langevin equation has two main parts – the mean drift term and the turbulence term. The proposed model will separate the turbulence term into the effects by Type-A eddies and the effects by Type-B eddies, respectively. In the simulation results of sediment concentration in Tsai & Huang (2019), it can be found that when only Type-A eddies are considered, there were some discrepancies except for the near wall region within about 20% of the thickness of turbulence boundary layer. Hence, after taking into account for the effects of Type-B eddies in the proposed model, it can be expected that accuracy of the simulation results of Lagrangian particle trajectories and sediment concentrations can be improved throughout the whole boundary layer.

Keywords: Lagrangian methods, stochastic particle tracking model, attached eddies, Brownian motion, particle trajectories
What do long term field surveys tell us about the economic impacts of flooding on agricultural activities?
Authors: Bremond Pauline , Balzergue Pierre , Garcia Pauline , Kechichian Loïc , Perret Nicolas , Pouillet Alexandra , Grelot Frédéric
Published: March 2021

Estimating damage is crucial to evaluate flood management policies and to choose between different alternatives. In Cost-Benefit Analysis, the benefits of the policies are most of the time evaluated by avoided damage. One of the underlying assumptions of damage estimation is that the impacted assets come back quickly to their initial state, which justifies the assumption to focus on short term damage. So far, little research has questioned this assumption. However, recent work (Nortes Martinez, 2019) showed that flooding can critically disrupt farming systems in the long term. The vulnerability of agricultural activities to flooding has received so far less attention because they represent less damage proportionally compared to other economic sectors. However, better characterizing impacts on such assets is key to evaluating the efficiency and sustainability of flood management policies which relies on increasing exposure on agriculture. In this article, we propose to address the issue of long term field surveys to improve the assessment of flood-related damage to agricultural activities. To do so, we carried out interviews in 2015 with farmers impacted in 2014 by a flood, and which was repeated in 2019 and 2020. The case study is the “Étang de l’Or” watershed, located in the South of France in the Occitanie Region. It was impacted by an extreme flood in September 2014. 70 impacted farms were identified representing a total area of 3 044 ha of which 340 ha were affected. The main specialization of these farms were viticulture (27 farms) and market gardening and horticulture (27 farms). In 2015, a first round of surveys was carried out. A questionnaire aimed at having a global vision of the impacts on farms was used. 41 farms responded to the interviews (14 in viticulture and 16 in marketing gardening horticulture), which were carried out face-to-face. In 2019 and 2020, a second round of surveys was carried out with the farms specialised in viticulture and in market gardening and horticulture. A questionnaire was designed to investigate impacts that have occurred since 2014 as well as the potential adaptions implemented. 10 farms specialised in viticulture and 11 specialised in market gardening participated to the second round respectively 4 and 5 years after the first interviews. Long term surveys revealed that few biophysical impacts have persisted after the 2014 flood, for example long term loss of yield or impact on quality of the products. However, financial impacts were still present 5 years after: repayment of loans, replenishment of the cash fund. Although a full correlation cannot be established, some farms have gone bankrupt. In conclusion, we present methodological recommendations for the implementation of a long-term observation framework for flood impacts.
Experimental measurement of the cutting forces and wear of the drill in processing X17CrNi16-2 martensitic stainless steel
Authors: Rosca Adrian Sorin , Craciunoiu Nicolae , Geonea Ionut Daniel , Ciurezu Gherghe Leonard
Published: March 2021

Abstract. For the optimum setup of an industrial manufacturing
process, it can be important to know the drilling forces and moments. In
many cases, theoretical estimates are not accurate enough, especially when
dealing with new materials, and experimental measurements are mandatory.
This paper presents the design of a dynamometer comprising a one-spoked wheel
elastic component to measure the drilling thrust force and the drilling
moment. A finite element analysis was made, using Ansys software, to find the most favorable position for the strain gauges. One set of strain gauges was bonded to spokes to determine the torque, and a second set was bonded to the other two spokes to quantify the axial thrust force. After dynamometer manufacturing, a calibration operation is achieved, and tests are performed by measuring the drilling forces, thrust, and torque on American Iron and Steel Institute (AISI) 1020 steel. The analogue signals from the gauges were recorded using a computer with a data
acquisition device. Tool wear is studied, and the results are presented in
the paper. A good agreement between results from the literature and computations demonstrates the efficiency and accuracy of this measuring instrument.
PENERAPAN PENDEKATAN KONTEKSTUAL DALAM MODEL PEMBELAJARAN KOOPERATIF TIPE JIGSAW UNTUK MENCAPAI HASIL BELAJAR MATERI PERPINDAHAN KALOR PADA SISWA KELAS VII SMP NEGERI 2 AMBON
Authors: Siregar Nur Hamida
Published: March 2021

The quality of education in Indonesia was in the worst position in Asian from 12 countries surveyed in 2010 by PERC, so more efforts by teachers are needed to improve the quality of education. One of the efforts is through the application of good and appropriate learning models to the characteristics of subjects. This study aimed to determine the achievement of learning outcomes of heat transfer subject of students of class VII6 SMP Negeri 2 Ambon through application of a contextual approach in Jigsaw type cooperative learning model. This research was a quantitative descriptive, with 40 students. This study found that the average score of initial achievement was 29.22 (failed qualification). While during the learning process with Jigsaw cooperative learning model, the average cognitive achievement was 83.34 (good qualification), affective was 82.66 (good qualification), and psychomotor was 88.75 (good qualification). While there were formative test results obtained the average achievement score was 74.77 (sufficient qualification), and the average of the final score was 81.71 (good qualification). It can be concluded that the learning process by applying a contextual approach in Jigsaw type cooperative learning model was proven to help students in achieving the learning outcomes of heat transfer subject.
Student Learning Difficulty Problems In Islamic Counseling Perspective And Solutions To Handling At Islamic Senior High School (MAPN) 4 Medan
Authors: Dina Aulia Solihah Titin Sumanti,
Published: March 2021

The purpose of this study is to analyze what types of learning difficulties are faced by students, implementation solutions for handling student learning difficulties in the perspective of Islamic counseling, obstacles from solutions to handling students' learning difficulties in the perspective of Islamic counseling, and the efforts made in overcoming difficulties in handling difficulties. student learning in the perspective of Islamic counseling. This research method is to use a phenomenological qualitative research method, which is to reveal the problems that occur to find and understand what is hidden behind the problems that occur. Research implementation Qualitative phenomenology is aiming to understand and interpret the various problems that exist. The result of this research is the difficulty learning that experienced by students in Senior High School 4 Terrain is difficult to understand the eye subjects specified as subjects of mathematics and physics so that the results of learning low. Students work to help the elderly that causes the activity of learning the students there are disturbed Students experience fatigue from working too much to help their parents in certain endeavors. Students are bored with learning because there are too many assignments given from school, especially subject assignments given by teachers at school. Solution problems of difficulty of learning of students in the perspective of counseling Islami which provides guidance with techniques conventional ie conduct meetings directly with the students, and then perform the stages of identifying problems.
The role of cultural diplomacy in relations between Kazakhstan and Italy
Authors: KENZHALINA Gulsum , KUSSAINOVA Aliya , AITMAGAMBETOV Duman , BOLYSBEKOVA Moldir
Published: March 2021

At the present stage, cultural diplomacy plays an important role in relations between countries. The implementation of cultural diplomacy contributes not only to the promotion of the country's interests abroad in the field of cultural policy, but also can create favorable conditions for the effective achievement of the country's foreign policy goals in other areas (for example, economic). The article deals with the bilateral cultural diplomacy of Kazakhstan and Italy. Cultural contacts between the two countries, starting from the early Middle Ages, are consistently examined and analyzed, on the basis of which a conclusion is drawn about the effectiveness of certain aspects of foreign cultural policy in creating bilateral relations. An attempt was also made to answer the question of how cultural methods can contribute to the harmonization of relations between Kazakhstan and Italy at the present stage, and whether they can significantly affect the current state of their political and economic cooperation.
Determinants of CO2 emissions in the ASEAN Economies: The Role of Renewable and Non-renewable Energy
Authors: Nawab Tabish , Aamir Muhammad Faizan
Published: March 2021

According to the literature of energy-growth-environment, a numeral of studies aims to recognize the factors of CO2 (carbon dioxide) emissions resulting from significant increases in CO2 emissions in recent decades. The selection of data is the main criticism connected to the present literature. Most of the studies used the overall consumption of energy, and other criticism concerns selecting panel assessment techniques. Nearly all the previous research used general panel approaches that overlooked long term dependence. This empirical study fills the gap revealed in the past studies of the effect of trade openness, income, non-renewable and renewable energy on carbon emissions in the presence of EKC (Kuznets environmental curve) for the ASEAN economies from the time spam 2000 to 2018 using panel ARDL, Pooled Mean Group (PMG) estimation techniques. The results of the PMG estimator confirm the presence of the EKC hypothesis in selected ASEAN countries. Furthermore, Trade and renewable energy minimize carbon dioxide emissions, whereas non-renewable upsurges CO2 emissions. The outcomes also revealed cointegration amongst carbon emissions and renewable energy and one-way causation found from income to CO2 productions, non-renewable energy to carbon emissions, and trade openness toward carbon dioxide emissions. Moreover, it concluded that ASEAN states that the government should advise the industries and all sectors to modify their energy sources from non-renewable energy sources to renewable energy sources. Because it helps to increase the level of energy and economic growth in reducing the carbon emission level.
Tourism and Hospitality Industry During COVID-19: An Economic Perspective
Authors: Mohamed Muharis , Patwary Ataul Karim , Mohamed Ahmad Edwin
Published: March 2021

The COVID-19 pandemic has caused an ongoing tourism crisis. The most significant threat to the global economy since the Second World War is the product of unparalleled global travel constraints and residency orders. Tourism is particularly vulnerable to intervention to fight pandemics due to limited movement and social distance. Global markets, including tourist services such as world travel, domestic tourism, day trips, and parts as varied as air, cruises, transport, hotels, cafes and restaurants, conferences, festivals, meetings, or sports activities have automatically been affected by international, regional, and local travel restrictions. Leading to the dramatic stagnation of global air traffic and the fact that many countries have placed travel restrictions, closed borders, or initiated quarantine times, international and domestic tourism has reduced dramatically. Several countries have failed to return tourists home, with hundreds of thousands of people in all areas of the world participating in vital outbound markets. This study contributes to the tourism and hotel industry, particularly from an economic perspective, by reviewing related research, reports, and working papers.
Pedagogia do ser mais
Authors: Dickmann Ivo
Published: March 2021

Breve introdução à antropologia de Paulo Freire
Nærhet, eller distanse? Lærerstudenters erfaringer med Zoomundervisning under Covid-19
Authors: Goth Ursula Småland , Jermstad Linnéa K. , Jokstad Gunnvi Sæle , Holovchuk Svitlana
Published: March 2021

Våren 2020 vil for mange bli husket som meget utfordrende. Smittevernrestriksjoner i forbindelse med Covid-19 ble innført i hele Norge. Det førte til at høgskolene og universitetene måtte begrense antall mulig tilstedeværende i klasserommet til 20 studenter. Zoom ble derfor innført som digital interaksjonsplattform. Fra mars til feriestart i juli 2020 ble fysisk oppmøte i undervisning unngått. Overgang fra stedsbasert til rent internettbaserte undervisningsplattformer førte til store endringer for både studenter og lærere. Denne studien belyser lærerutdanningsstudenters opplevelse og refleksjoner etter innføringen av Zoom. Studien ser videre på læringsutbytte og endring av motivasjon. Data som ble inkludert i studien baserer seg på en digital spørreundersøkelse ved oppstarten av 5. semester i grunnskolelærerutdanningen av 50 studenter. Etter intervjuene gjennomførte vi et strukturert litteratursøk. Deretter ble studentenes svar tolket, kategorisert og analysert. Våre resultater viste at motivasjonen hos studenter endret seg over tid ved at den sosiale interaksjonen ble sterkt redusert. Data viste også at studentene opplevde redusert læringsutbytte og frustrasjon. Studien konkluderer med at studentene opplever redusert motivasjon ved rene internettbaserte undervisningsformer (Zoom), en reduksjon i motivasjonen som hadde innvirkning på egenopplevd helse og livsmestring.
Kvalitetsfremmende praksis i arbeidet med de grunnleggende ferdighetene
Authors: Unneland Anne Karin Rudjord
Published: March 2021

Grunnleggende ferdigheter som begrep ble innført i grunnopplæringen i Norge med læreplanreformen Kunnskapsløftet i 2006. De fem grunnleggende ferdighetene å lese, å skrive, å regne, muntlige ferdigheter, og digitale ferdigheter skal utvikles som fellesoppgave for alle fag i skolen. Forskning viser at det er ulike forståelser av begrepet grunnleggende ferdigheter og at mange lærere tenker i kategorien elementære ferdigheter og at det handler om å lære inn en ferdighet. Det kan være grunn til å anta at ferdighetsbegrepet langsomt er blitt utarmet i vår moderne tid. Kanskje er det slik at fordi det praktiske og håndverksmessige er blitt devaluert de siste tiår, mangler lærere en dyp forståelse av hvordan ferdigheter læres og videreutvikles, og hvilke tenkemåter som kan utvide forståelsen av ferdigheter. Formålet med artikkelen er å bidra i en diskusjon om hva som kan forsterke trangen og viljen til å forbedre ferdigheter. Artikkelen reflekterer over hvordan kvaliteten kan fremmes i utvikling av grunnleggende ferdigheter i skolesammenheng. Teksten drøfter dette spørsmålet med utgangspunkt i teori fra mesterlæretradisjonen. Perspektivene utvides ved teoretikere som Richard Sennett, Donald Schön og Aristoteles. Det ble tydelig i litteraturstudien at klasserommet som et lærende fellesskap med lærere som gir innsatsen og resultatene verdi, er av stor betydning. Kvalitet kan fremmes gjennom refleksjon og en systematisk og gjennomtenkt tilbakemeldingskultur, der det å gjøre feil ses på som en hjelp til mer læring og ikke minst at det i klassefellesskapet verdsettes og gis rom for forskjellighet, ulike mål og ulike mestringsnivåer.