bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase space density analysis of outer radiation belt electron energization and loss during geoeffective and non-geoeffective sheath regions
Authors: Kalliokoski Milla , Kilpua Emilia , Osmane Adnane , Jaynes Allison , Turner Drew , George Harriet , Turc Lucile , Palmroth Minna
Published: March 2021

The energetic electron content in the Van Allen radiation belts surrounding the Earth can vary dramatically on timescales from minutes to days, and these electrons present a hazard for spacecraft traversing the belts. The outer belt response to solar wind driving is however yet largely unpredictable. Here we investigate the driving of the belts by sheath regions preceding interplanetary coronal mass ejections. Electron dynamics in the belts is governed by various competing acceleration, transport and loss processes. We analyzed electron phase space density to compare the energization and loss mechanisms during a geoeffective and a non-geoeffective sheath region. These two case studies indicate that ULF-driven inward and outward radial transport, together with the incursions of the magnetopause, play a key role in causing the outer belt electron flux variations. Chorus waves also likely contribute to energization during the geoeffective event. A global picture of the wave activity is achieved through a chorus proxy utilizing POES measurements. We highlight that also the non-geoeffective sheath presented distinct changes in outer belt electron fluxes, which is also evidenced by our statistical study of outer belt electron fluxes during sheath events. While not as intense as during geoeffective sheaths, significant changes in outer belt electron fluxes occur also during sheaths that do not cause major geomagnetic disturbances.
Changes in Atlantic Water circulation patterns and volume transports North of Svalbard over the last 12 years (2008-2020) 
Authors: Athanase Marylou , Provost Christine , Artana Camila , Pérez-Hernández Maria Dolores , Sennéchael Nathalie , Bertosio Cécilia , Garric Gilles , Lellouche Jean-Michel , Prandi Pierre
Published: March 2021

Atlantic Water (AW) enters the Arctic through Fram Strait as the West Spitsbergen Current (WSC). When reaching the south of Yermak Plateau, the WSC splits into the Svalbard, Yermak Pass and Yermak Branches. Downstream of Yermak Plateau, AW pathways remain unclear and uncertainties persist on how AW branches eventually merge and contribute to the boundary current along the continental slope. We took advantage of the good performance of the 1/12° Mercator Ocean model in the Western Nansen Basin (WNB) to examine the AW circulation and volume transports in the area. The model showed that the circulation changed in 2008-2020. The Yermak Branch strengthened over the northern Yermak Plateau, feeding the Return Yermak Branch along the eastern flank of the Plateau. West of Yermak Plateau, the Transpolar Drift likely shifted westward while AW recirculations progressed further north. Downstream of the Yermak Plateau, an offshore current developed above the 3800 m isobath, fed by waters from the Yermak Plateau tip. East of 18°E, enhanced mesoscale activity from the boundary current injected additional AW basin-ward, further contributing to the offshore circulation. A recurrent anticyclonic circulation in Sofia Deep developed, which also occasionally fed the western part of the offshore flow. The intensification of the circulation coincided with an overall warming in the upper WNB (0-1000 m), consistent with the progression of AW. This regional description of the changing circulation provides a background for the interpretation of upcoming observations.
Impact of Arctic gateways closure on the Atlantic Meridional Overturning Circulation in the Pliocene
Authors: Weiffenbach Julia , Baatsen Michiel , von der Heydt Anna
Published: March 2021

The mid-Pliocene climate is the most recent geological period with a greenhouse gas concentration of approximately 400 ppmv, similar to the present day. Proxy reconstructions indicate enhanced warming in the high North Atlantic in the mid-Pliocene, which has been suggested to be a response to a stronger Atlantic Meridional Overturning Circulation (AMOC). PlioMIP2 ensemble results show a stronger AMOC and simulated North Atlantic sea surface temperatures (SSTs) match reconstructions better than PlioMIP1. A major difference between PlioMIP1 and PlioMIP2 is the closure of the Bering Strait and Canadian Archipelago in the Pliocene. Previous studies have shown that closure of these Arctic gateways leads to an enhanced AMOC due to altered freshwater fluxes in the Arctic.

Analysis of our Community Earth System Model (CESM1) simulations shows that the simulated increase in North Atlantic SSTs and strengthened AMOC in the Pliocene is a result of Pliocene boundary conditions rather than CO2 concentration increase. Here we compare results from two runs with pre-industrial boundary conditions and 280 and 560 ppmv CO2 concentrations and three runs with PlioMIP2 boundary conditions and 280, 400 and 560 ppmv CO2 concentrations. Results show a 10-15% stronger AMOC in the Pliocene simulations as well as enhanced warming and saltening of the North Atlantic sea surface. While there is a stronger AMOC, the Atlantic northward ocean heat transport (OHT) in the Pliocene simulations only increases 0-3% with respect to the pre-industrial. Analysis indicates there is an altered relationship between the AMOC and OHT in the Pliocene, pointing to fundamentally different behavior of the AMOC in the Pliocene simulations. This is supported by a specific spatial pattern of deep water formation (DWF) areas in the Pliocene simulations that is significantly different from that of the pre-industrial. In the Pliocene simulations, DWF areas adjacent to south Greenland disappear and new DWF areas appear further southwards in the Labrador Sea off the coast of Newfounland. These results indicate that insight into the effect of the palaeogeographic boundary conditions is crucial to understanding the Pliocene climate and its potential as a geological equivalent to a future greenhouse climate.
Is the ocean enough? – Indications towards the origin of Ice Nucleating Particles from May to July in the Arctic
Authors: Hartmann Markus , Gong Xianda , Kecorius Simonas , van Pinxteren Manuela , Vogl Teresa , Welti André , Wex Heike , Zeppenfeld Sebastian , Wiedensohler Alfred , Herrmann Hartmut , Stratmann Frank
Published: March 2021

Low-level mixed-phase clouds are important factors influencing the energy budget of the Arctic boundary layer. The radiative properties of these clouds are determined by their microphysical properties. Aerosol particles that act as Ice Nucleating Particles (INP), impact the primary ice formation inside clouds and thereby affect cloud lifetime, albedo and precipitation formation. The sources of INP in the Arctic, their properties, nature and concentration are poorly understood which results in substantial uncertainties radiative forcing estimates in climate models.

Here, we present ship-based measurements of INP in different environmental compartments (air, sea surface microlayer, bulk sea water, fog water) in the Arctic. From May to July 2017 the PASCAL field campaign took place around and north of Svalbard (up to 84°N, between 0° and 35°E) onboard the RV Polarstern. INP concentrations were measured online with the SPIN instrument (Spectrometer for Ice Nuclei, DMT) and offline through filter sampling and analysis with freezing array techniques. We assess possible connections between the INP in the sea water and air, as well as between INP in the fog water and air through a closure study.

Generally, INP concentrations in the Arctic were found to be lower than in mid-latitudes with the exception of elevated INP concentrations at temperatures above -15°C and below -30°C. We attribute elevated INP concentrations to the presence of biogenic, probably proteinaceous INP, at the warmer, and to the presence of mineral dust at colder temperatures, respectively. The closure studies revealed that:
a) all INP in the air are activated to fog droplets, and
b) the INP concentration in seawater alone cannot explain INP concentration in air without a substantial enrichment of INP (factor 104 to 105) during the transfer of INP from the sea surface to the atmosphere. 
We present indications for a local, marine source of INP from a case study looking at the period when atmospheric INP concentrations were highest in the temperature range above -15°C. These findings highlight the need for future studies to assess especially the production mechanisms and source strength for Arctic INP.

We gratefully acknowledge the funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Projektnummer 268020496 – TRR 172, within the Transregional Collaborative Research Center “ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms (AC)3
Low-cost biosensors for continuous performance assessment of natural-based wastewater treatment systems
Authors: Fernandez-Gatell Marta , Sanchez-Vila Xavier , Puigagut Jaume
Published: March 2021

Bioelectrochemical systems (BES) are devices that transform the chemical energy of organic and inorganic substrates into an electric current. BES represents a particularly interesting biosensor technology for monitoring the performance of  remote/isolated wastewater treatment facilities (such as constructed wetlands). The work presented here aimed to assess the potential use of the electric signal produced by low-cost, membrane-less BES systems as an indicator of the operational conditions and treatment performance of natural-based wastewater treatment systems. For this purpose, several BES configurations and operation modes working under real domestic wastewater conditions were monitored.

Results showed that the electric current produced by the BES significantly correlates with key parameters in biological-based wastewater treatment systems such as microbial activity and biomass, water COD or solids accumulation. Therefore, our work demonstrates the feasibility of applying bioelectrochemical-based low-cost biosensors for the improvement and control of natural-based wastewater treatment systems.

 

 

Keywords: bioelectrochemical systems, wastewater, microbial activity, organic matter, low-cost, biosensor
Deep learning approach for calibrating Cosmic-Ray Neutron Sensors (CRNS) in area-wide soil moisture monitoring
Authors: Mbaye Modou , Said Hami , Franz Trenton , Weltin Georg , Dercon Gerd , Heng Lee kheng , Fulajtar Emil , Strauss Peter , Rab Gerhard , Ndiaye Mapathe
Published: March 2021

Traditional field calibration of cosmic-Ray neutron sensors (CRNS) for area-wide soil moisture monitoring is based on time-consuming and often expensive soil sample collection and conventional soil moisture measurement. This calibration requires two field campaigns, one under dry and one under wet soil conditions. However, depending on the agro-ecological context more field campaigns may be required for calibration, due to for instance crop biomass water interference. In addition, the current calibration method includes corrections considering several parameters influencing neutron counts, the proxy for soil moisture, such as soil lattice water, organic carbon, and biomass which need to be measured.

The main objective of this study is to investigate and develop an alternative calibration method to the currently available field calibration method. To this end, a Deep Learning model architecture under the TensorFlow machine learning framework is used to calibrate the Cosmic-Ray sensor.

The Deep Learning model is built with more than 8 years of CRNS data from Petzenkirchen (Austria) and consists of four hidden layers with activation function and a succession of batch normalization. Prior to build the Deep Learning model, data analysis consisting of pertinent variables selection was performed with multivariate statistical analysis of correlation. Among nine features, five were effectively pertinent and included in the machine learning artificial neural network architecture. The five input variables were the raw neutrons counts (N1 and N2), humidity (H), air pressure (P4) and temperature (T7).

The preliminary results show a linear regression with an R2 of 0.97 and the model predicted the soil moisture with less than 1% error.

These preliminary results are encouraging and proved that a machine learning based method could be a valuable alternative calibration method for CRNS against the current field calibration method.

More investigation will be performed to test the model under different agro-ecological conditions, such as Nebraska, USA. Further, additional input variables will be considered in the development of machine learning based models, to bring in agro-ecological information, such as crop cover, growth stage, precipitation related to the CRNS footprint. 
Layered mantle flow beneath the Japan Sea and NE China from inversion of surface wave dispersion using rj-MCMC method
Authors: Zhao Yanzhe , Guo Zhen , Wang Yanbin , Fan Xingli
Published: March 2021

The surface wave dispersion data with azimuthal anisotropy can be used to invert for the wavespeed azimuthal anisotropy, which provides essential dynamic information about depth-varying deformation of the Earth’s interior. The traditional method to slove this inversion problem is a two-step process, i.e. inverting the isotropic wavespeed first, based on which the anisotropic part is solved successively. In this study, we try to simultaneously invert both the isotropic and anisotropic shear wave velocity using the rj-MCMC (reversible jump Markov Monte Carlo) algorithm, which allows sampling the model space in a transdimensional way.

Our resarch is conducted in the Northeast Aisa, including the East and Northeast China (EC and NEC), Korean Peninsula and the sea of Japan (see Fig. 1). The previous anisotropic and tomographic studies were mainly conducted on separated continents, lacking a panoramic view of geodynamics across the entire region. In this study, we construct a crustal and uppermantle model of the whole ragion based on the Rayleigh wave dispersion data collected by Fan et al. (2020, GRL), and acquire high-resolution patterns reflecting valuable geodynamic characteristics.

 

Figure 1. Map of the NE Asia showing the main tectonic features. Major blocks: NEC = north-east China; EC = East China; KP = Korean Peninsula; KS = Korea Strait; SoJ = Sea of Japan; JI = Japanese Island. The gray area in the background delineates the major sedimentary basins with thickness no less than 1.5 km. Red volcano symbols denote the Late Cenozoic intraplate volcanoes, including: CBV = Changbaishan volcano; JPHV = Jingpohu volcano; LGV = Longgang volcano; XJDV = Xianjingdao volcano; CRV = ChugaRyong volcano; ULV = Ulleung volcano; HLV = Halla volcano; FJV = FukueJima volcano. Small red triangles show the locations of island arc volca-noes. The Japan Trench where the western Pacific Plate subducts, and the Ryukyu Trench where the Philippine Sea Plate subducts are outlined by black lines with white sawtooth. Interface depths of the subducting Pacific slab and Philippine Sea slab are marked by white and purple dashed lines, respectively, with depth annotation. The Tanlu fault zone (TLFZ) is represented by thin black lines.
Organic matter transport by cyclonic eddies formed in eastern boundary upwelling system supports heterotrophy in the open oligotrophic ocean
Authors: Devresse Quentin , Becker Kevin W , Engel Anja
Published: March 2021

Mesoscale eddies formed in Eastern boundary upwelling systems are elementary components of ocean circulation and play important roles in the offshore transport of organic carbon and nutrients. Yet, most of our knowledge about this lateral transport and its influence on biogeochemical cycles relies on modelling studies and satellite observations, while in situ measurements of biogeochemical parameters are scarce. For example, little is known about the effects of mesoscale eddies on organic carbon distribution, microbial activity, and organic matter (OM) turnover in the open oligotrophic ocean. To address this gap, we investigated the horizontal and vertical variability of phytoplankton and bacterial activity as well as dissolved organic carbon along a zonal corridor of the westward propagation of eddies between the Cape Verde Islands and Mauretania in the Eastern Tropical North Atlantic (ETNA). We additionally collected samples from a cyclonic eddy along this transect at high spatial resolution. Our results indicate a strong impact of cyclonic eddies on both microbial abundance and metabolic activity in the epipelagic layer (0–200 m). Generally, all determined parameters (bacterial abundance, heterotrophic respiration rates, bacterial biomass production, bacterial growth efficiency, bacterial carbon demand and net primary production) were higher in the eddy than in the stations along the meridional transect. Along the transect, microbial biomass and activity rates were gradually decreasing from the coast to the open ocean. We further observed high variability of biogeochemical parameters within the eddy with elevates microbial abundances as well as process rates in the south-western periphery. This can be explained by the rotational flow of the cyclonic eddy, which perturbs local OM and nutrient distribution via azimuthal advection. The local positive anomaly of microbial activity in the cyclonic eddy compared to all other stations including the near coast ones results from eddy pumping of nutrient into the epipelagic layer that promotes growth of phytoplankton. Overall, our study supports that cyclonic eddies are important vehicles for the transport of fresh OM that fuel heterotrophic activity the open ocean, highlighting the coupling between productive EBUS and the adjacent oligotrophic ETNA.
Numerical simulation of the Late Jurassic closure of the Vardar Tethys
Authors: Stanković Nikola , Cvetkov Vesna , Cvetković Vladica
Published: March 2021

We report updated results of our ongoing research on constraining geodynamic conditions associated with the final closure of the Vardar branch of the Tethys Ocean by means of application of numerical simulations (previous interim results reported in EGU2020-5919).

The aim of our numerical study is to test the hypothesis that a single eastward subduction in the Jurassic is a valid explanation for the occurrence of three major, presently observed geological entities that are left behind after the closure of the Vardar Tethys. These include: ophiolite-like igneous rocks of the Sava-Vardar zone and presumably subduction related Timok Magmatic Complex, both Late Cretaceous in age as well as Jurassic ophiolites obducted onto the Adriatic margin. In our simulations we initiate an intraoceanic subduction in the Early/Middle Jurassic, which eventually transitions into an oceanic closure and subsequent continental collision processes.

In the scope of our study numerical simulations are performed by solving a set of partial differential equations: the continuity equation, the Navier-Stokes equations and the temperature equation. To this end we used I2VIS thermo-mechanical code which utilizes marker in cell approach with finite difference discretization of equations on a staggered grid [Gerya et al., 2000; Gerya&Yuen, 2003].

The 2D model consists of two continental plates separated by two oceanic slabs connected at a mid-oceanic ridge. Intraoceanic subduction is initiated along the ridge by assigning a weak zone beneath the ridge. Time-dependent boundary conditions for velocity are imposed on the simulation in order to model a transient spreading period. The change of sign in plate velocities is found to be useful for both obtaining obduction / ophiolite emplacement [Duretz et al., 2016] and causing back-arc extension. Changes in velocities are linear in time. Simulations follow a three-phase evolution of velocity boundary conditions consisting of two convergent phases separated by a single divergent phase where spreading regime is dominant. Effect of duration and magnitude of the second phase on model evolution is also explored.

Our so far obtained simulations were able to reproduce the westward obduction and certain extension processes along the active (European) margin, which match the existing geological relationships. However, the simulations involve an unreasonably short geodynamic event (cca 15-20 My) and we are working on solving this problem with new simulations. 
Micro-inclusions in the EGRIP ice core identified with Raman-spectroscopy
Authors: Stoll Nicolas , Eichler Jan , Hörhold Maria , Erhardt Tobias , Weikusat Ilka
Published: March 2021

Soluble and insoluble impurities play a crucial role regarding the deformability and thus the flow of polar ice. To better understand this interplay from a mechanistic point of view it is especially important to investigate the location and chemical composition of micro-inclusions (Stoll et al., 2021), which are among the most abundant impurities in polar ice.

New results from a systematic analysis of micro-inclusions in Holocene ice from the East Greenland Ice Core Project (EGRIP), which has been drilled near the onset of the Northeast Greenland Ice Stream (NEGIS), offer unique insights into the dynamics of fast flowing ice over different scales, ranging from kilometres to micrometres.

Investigating the small-scale properties of eleven samples from Holocene ice, i.e. the upper 1340 m of the EGRIP ice core, we mapped the locations of several thousand micro-inclusions inside the ice. The use of cryo-Raman spectroscopy allowed us to obtain a representative overview of the mineralogy of these inclusions in the ice without the risk of contamination.

We identified a variety of Raman spectra, mainly from sulphates (dominated by gypsum) and terrestrial dust, such as quartz, mica and feldspar. The observed mineralogy changes with depth and EGRIP Holocene ice can be categorised in two different depth regimes, i.e. the upper (100-900 m) and lower (900-1340 m) regimes, depending on their mineralogy. Furthermore, micro-inclusions show certain spatial patterns, such as clustering or layering, which are partly related to their mineralogy. We thus conclude that Greenlandic Holocene ice has a broader, and more variable, mineralogy than previously reported and that chemical reactions might take place within the ice sheet, possibly altering the paleo-climate record. Our approach further demonstrates the added value of systematic, combined high-resolution impurity and microstructural studies, and the importance of considering different spatial scales and is thus another step towards a more holistic understanding of impurities in ice.

Ref:
Stoll N, Eichler J, Hörhold M, Shigeyama W and Weikusat I (2021) A Review of the Microstructural Location of Impurities in Polar Ice and Their Impacts on Deformation. Front. Earth Sci. 8:615613. doi: 10.3389/feart.2020.615613
Strain-related carbon ordering on a sub-mm scale: a comparison of carbonate microfabrics and organic carbon nanostructure within a single sample.
Authors: Kedar Lauren , Bond Clare , Muirhead David
Published: March 2021

Organic carbon in rocks undergoes nanostructural changes when exposed to increased temperatures or strain. These changes can be identified using Raman spectroscopy, giving information about thermal maturity and strain conditions. However, it is well documented that in a heterogeneous rock, strain can be highly localised, evident in microstructural variations such as strain shadows, sub-grain development, twinning, and the rotation and alignment of crystal axes. In this study we map microstructural textures in deformed calcite through optical microscopy and EBSD of calcite crystal axes. This textural map is compared to mapped Raman spectral parameters of organic carbon particles in the same thin section. A comparison of the maps allows assessment of the extent to which Raman spectral parameters and hence carbon nanostructure is influenced by strain at a sub-mm scale. The study highlights the sensitivity of organic carbon nanostructure to sub-mm scale changes in strain localisation within a single deformed carbonate sample.
The effect of growing-season productivity on autumn phenology in temperate trees
Authors: Zohner Constantin
Published: March 2021

Phenological shifts in plants greatly affect biotic interactions and lead to multiple feedbacks to the climate system. Increases in growing-season length under warmer climates are expected to drive changes in water, nutrient, and energy fluxes as well as enhancing ecosystem carbon uptake. Yet, future trajectories of growing-season lengths remain highly uncertain because the intrinsic and extrinsic factors triggering autumn leaf senescence, including lagged effects of spring and summer productivity, are poorly understood. Here, we use 434,226 spring leaf-out and autumn leaf senescence observations of temperate trees from Central Europe between 1948 and 2015 to test the effect of seasonal photosynthetic activity on leaf senescence, thereby exploring the extent to which growing-season lengths are internally regulated by constraints on productivity. We found that spring and summer productivity was a critical driver of autumn phenology, with earlier leaf senescence in years with high seasonal photosynthetic activity. Our new process-based model, incorporating information on growing-season photosynthesis, increased the accuracy of existing autumn phenology models by 22–61%. Furthermore, the physiological constraint of growing-season photosynthesis reversed the predictions of autumn phenology over the rest of the century. While current phenology models predict that leaf senescence will occur 7–19 days later by the end of the 21st century, we estimate that leaf senescence will, in fact, advance by 3–6 days. Our results reveal important constraints on future growing-season lengths and the carbon uptake potential of temperate trees and enhance our capacity to forecast long-term changes in ecosystem functioning, which is critical to improve our understanding of Earth System dynamics in response to climate change.
Estimating the water balance and uncertainty bounds in a highly groundwater-dependent and data-scarce areas: An example for the upper Citarum basin
Authors: Rusli Steven Reinaldo , Weerts Albrecht , Bense Victor
Published: March 2021

In this study, we estimate the water balance components of a highly groundwater-dependent and hydrological data-scarce basin of the upper reaches of the Citarum river in West Java, Indonesia. Firstly, we estimate the groundwater abstraction volumes based on population size and a review of literature (0.57mm/day). Estimates of other components like rainfall, actual evaporation, discharge, and total water storage changes are derived from global datasets and are simulated using a distributed hydrological wflow_sbm model which yields additional estimates of discharge, actual evaporation, and total water storage change. We compare each basin water balance estimate as well as quantify the uncertainty of some of the components using the Extended Triple Collocation (ETC) method.

The ETC application on four different rainfall estimates suggests a preference of using the CHIRPS product as the input to the water balance components estimates as it delivers the highest r2  and the lowest RMSE compared to three other sources. From the different data sources and results of the distributed hydrological modeling using CHIRPS as rainfall forcing, we estimate a positive groundwater storage change between 0.12 mm/day - 0.60 mm/day. These results are in agreement with groundwater storage change estimates based upon GRACE gravimetric satellite data, averaged at 0.25 mm/day. The positive groundwater storage change suggests sufficient groundwater recharge occurs compensating for groundwater abstraction. This conclusion seems in agreement with the observation since 2005, although measured in different magnitudes. To validate and narrow the estimated ranges of the basin water storage changes, a devoted groundwater model is necessary to be developed. The result shall also aid in assessing the current and future basin-scale groundwater level changes to support operational water management and policy in the Upper Citarum basin.
Transitions between dry and wet periods in Europe during 1950–2019
Authors: Bestakova Zuzana , Maca Petr , Kysely Jan , Singh Ujjwal , Markonis Yannis , Hanel Martin
Published: March 2021

The study deals with probabilities of transitions from arid to humid environment and vice versa in
Europe. Aridity index, defined as a ratio of potential evapotranspiration and precipitation and
representing the ratio between energy availability and water availability, is used to characterize humid
(wet) and arid (dry) regions and allows us to study transitions between individual periods (wet-wet,
wet-dry, dry-dry, dry-wet). Three gridded datasets – CRU (UEA, 2020), E-OBS (ECAD, 2020) and ERA5
(ECMWF, 2020) – are used for this purpose. The aim of the study is to compare the three datasets as
to transitions between wet and dry conditions, which are determined according to the aridity index,
and evaluate the variability in Europe over 1950–2019. The changes in the aridity index since 1950 are
found to be most pronounced in Northern and Central Europe.

references:
ECAD, 2020: E-OBS gridded dataset, available from
.
UEA, 2020: University of East Anglia – Climatic Research Unit, available from
.
ECMWF, 2020: European Centre for Medium-Range Weather Forecasts – ERA5, available from
.
Multi-energy analysis of SPREAdFAST proton events
Authors: Miteva Rositsa , Kozarev Kamen , Nedal Mohamed
Published: March 2021

We present the procedure of event selection, data analysis and interpretation of solar energetic protons during the last solar cycle 24 for the needs of the SPREAdFAST project. Data from SOHO/ERNE and ACE/EPAM instruments have been analysed for nearly 100 proton events in the available energy bands. The energy dependence of the proton peak intensities and background spectra is completed. The energy range from a few to 130 MeV has been covered. Protons from the SPREAdFAST historical event list have been selected for a detailed comparative analysis. The validation between the observed and simulated proton events is presented and discussed.
A modern prototype three-layer stratification in the Arctic Ocean since the Miocene
Authors: Hossain Akil , Knorr Gregor , Jokat Wilfried , Lohmann Gerrit
Published: March 2021

The tectonic opening of the Fram Strait (FS) was critical to the water exchange between the Atlantic Ocean and the Arctic Ocean, and caused the transition from a restricted to a ventilated Arctic Ocean during early Miocene. If and how the water exchange between the Arctic Ocean and the North Atlantic influenced the global current system is still disputed. We apply a fully coupled atmosphere-ocean-sea-ice model to investigate stratification and ocean circulation in the Arctic Ocean in response to the opening of the FS during early to middle Miocene. Progressive widening of the FS gateway in our simulation causes a moderate warming, while salinity conditions in the Nordic Seas remain similar. On the contrary, with increasing FS width Arctic temperatures remain unchanged and salinity changes appear to steadily become stronger. For a sill depth of ~1500 m, we achieve ventilation of the Arctic Ocean due to enhanced import of saline Atlantic water through a FS width of ~105 km. Moreover, at this width and depth, we detect a modern-like three-layer stratification in the Arctic Ocean. The exchange flow through FS is characterized by vertical separation of a low salinity cold outflow from the Arctic Ocean confined to a thin upper layer, an intermediate saline inflow from the Atlantic Ocean below and a cold bottom Arctic outflow. Using a significantly shallower and narrower FS during the early Miocene, our study suggests that the ventilation mechanisms and stratification in the Arctic Ocean are comparable to the present-day characteristics.
Coupling the U.K. Earth System Model to dynamic models of the Greenland and Antarctic ice sheets
Authors: Smith Robin , Mathiot Pierre , Siahaan Antony , Lee Victoria , Cornford Stephen , Gregory Jonathan , Payne Antony , Jenkins Adrian , Holland Paul , Jones Colin
Published: March 2021

In this presentation we describe how models of the Greenland and Antarctic ice sheets have been incorporated in the global U.K. Earth System model (UKESM1) with a two-way coupling that passes fluxes of energy, water and the locations of ice surfaces between the component models. Offline, file-based coupling is used throughout to pass information between the components, which is both physically appropriate and convenient within the UKESM1 structure. Ice sheet surface mass balance is computed in the land surface model using sub-gridscale multi-layer snowpacks. Icebergs calved from the ice sheets are fed into a Langrangian iceberg drift scheme in the ocean. Ice shelf basal melt is explicitly calculated in cavities resolved by the ocean model, and ice sheet and shelf geometries are kept consistent in all components. We demonstrate that our coupled model remains stable when simulating changes in ice sheet height, extent and grounding-line position of hundreds of kilometres.
Wave-currents interaction in the Black Sea: new modelling approach for next generation of operational forecasting system.
Authors: Causio Salvatore , Lionello Piero , Ciliberti Stefania Angela , Coppini Giovanni
Published: March 2021

This study analyzes wave-currents interactions in the Black Sea basin focusing on deep water processes by using a coupled two-ways off-line numerical system, based on the ocean circulation model NEMO v4.0 and the third-generation wave model WaveWatchIII v5.16. The coupling between wave and hydrodynamical models is carried out at hourly frequency. The physical processes taken in consideration are: Stokes-Coriolis force, sea-state dependent momentum flux, wave induced vertical mixing, Doppler shift, and the stability parameter for the computation of effective wind speed. 

The hydrodynamical model is implemented over the Black Sea at the horizontal resolution of about 3km and 31 vertical levels, with closed boundary at the Bosporus Strait. The impact of the Bosporus Strait on the Black Sea dynamics is modeled using a surface boundary condition, taking into account the barotropic transport, which balances the freshwater fluxes on monthly basis (Stanev and Beckers, 1999; Peneva et al., 2001; Ciliberti et al., 2021). Additionally, Mediterranean waters inflow is represented by applying a local damping to high resolution temperature and salinity profiles (Aydogdu et al., 2018) at the Bosporus exit.

The wave model adopts the WW3 implementation of the WAM Cycle4 model physics, with Ultimate Quickest propagation scheme and GSE alleviation, over the same spatial grid as the hydrodynamical model Wind input and dissipation are based on Ardhuin et al. (2010), wave-wave interactions are based on Discrete Interaction Approximation. The wave spectrum is discretized using 24 directional sectors, and 30 frequencies, with 10% increment starting from 0.055Hz. Validation and statistical analysis of the results have been carried out to compare coupled and uncoupled runs, aiming to identify the model set-up to upgrade in the future the near real time operational system.

The evaluation of the coupling impact on significant wave height and temperature shows BIAS reduction, and even slight improvement of RMSE.
A New Pacific Influence on the Atlantic Meridional Overturning Circulation
Authors: Hermanson Leon , Smith Doug , Dunstone Nick , Eade Rosie
Published: March 2021

The Atlantic Meridional Overturning Circulation (AMOC) at 26N has been measured since 2004 by the RAPID-MOCHA array. On a multi-year timescale it shows a decline with signs of a recovery since around 2012. This variability is likely to be part of longer decadal variability. We examine here the decadal variability of the AMOC and its drivers in a coupled model run nudged to observations from 1960-2017. Temperature and winds are nudged throughout the atmosphere and potential temperature and salinity are nudged in the ocean, but the ocean velocities are allowed to vary freely. We nudge an ensemble of 10 ocean analyses into the ocean model to get an ensemble of responses, the mean of which reproduces the observed AMOC. We use these ocean-atmosphere re-analyses to study the drivers of the AMOC. The North Atlantic Oscillation (NAO) is well known to have an impact on the AMOC and is an important driver here. We find that the tropical Pacific also has a strong impact on the subtropical AMOC on multi-annual to decadal timescales. Together these two factors can explain more than half of all variability of the AMOC at 26N through wind forcing associated with Rossby waves and western boundary waves. This Pacific impact, not reported on before, is from windstress curl anomalies close to the East Coast of the southern US due to changes in the Pacific storm track and the Walker Circulation. As both the NAO and tropical Pacific variability is associated with solar and volcanic forcing, it is possible that solar and volcanic forcing are important for multi-annual to multi-decadal AMOC variability. We use observations of the NAO and tropical Pacific to reconstruct the AMOC from 1870 to present day and predict a continued recovery in the future.
PENGARUH DISCOVERY LEARNING DAN MOTIVASI TERHADAP SIKAP KRITIS MAHASISWA PADA MATERI LARUTAN
Authors: Aswana Aswana
Published: March 2021

Pembelajaran kimia pada materi larutan membutuhkan kreaktifitas yang sangat tinggi untuk meningkatkan sikap kritis mahasiswa dalam mengemukakan pendapat pada penentuan konsentrasi zat. Untuk itu  dosen dituntut  kreatif dalam  pemilihan dan penerapan strategi, metode, model atau pendekatan. Penelitian ini bertujuan untuk mengetahui pengaruh model Discovery Learning dan Motivasi terhadap sikap kritis mahasiswa pada  materi Larutan di Fakultas Pertanian  Universitas Muara Bungo tahun pelajaran 2017/2018. Penelitian ini adalah penelitian  eksperimen yang dilakukan terhadap 2 kelas sampel, dan setiap kelasnya berjumlah 30 mahasiswa dengan masing-masing diberi perlakuan yang berbeda. Data penelitian  diperoleh dari angket akhir untuk kedua kelas sampel. Hasil angket akhir dianalisis dengan mengunakan uji normaliatas, homogenitas dan analisis varian (ANAVA) satu jalur. Hasil penelitian menunjukan bahwa F hitung > F tabel  yaitu 8,23 > 4,18, disimpulkan bahwa terdapat perngaruh motivasi dan sikap kritis antara mahasiswa yang diajarkan metode Discovery Learning.
Factors Associated With Lower Limb Injuries in Recreational Runners: A Cross-Sectional Survey Including Mental Aspects and Sleep Quality
Authors: Mousavi Seyed Hamed , Hijmans Juha M. , Minoonejad Hooman , Rajabi Reza , Zwerver Johannes
Published: March 2021

Knowledge about prevalence and etiology of running-related injuries (RRIs) is important to design effective RRI prevention programs. Mental aspects and sleep quality seem to be important potential risk factors, yet their association with RRIs needs to be elucidated. The aims of this study are to investigate the epidemiology of RRIs in recreational runners and the association of mental aspects, sleep, and other potential factors with RRIs. An internet-based questionnaire was sent to recreational runners recruited through social media, asking for personal and training characteristics, mental aspects (obsessive passion, motivation to exercise), sleep quality, perceived health, quality of life, foot arch type, and RRIs over the past six months. Data were analyzed descriptively and using logistic regression. Self-reported data from 804 questionnaires were analyzed. Twenty-five potential risk factors for RRIs were investigated. 54% of runners reported at least one RRI. The knee was the most-affected location (45%), followed by the lower leg (19%). Patellofemoral pain syndrome was the most-reported injury (20%), followed by medial tibial stress syndrome (17%). Obsessive passionate attitude (odds ratio (OR):1.35; 95% confidence interval (CI):1.18-1.54), motivation to exercise (OR:1.09; CI:1.03-1.15), and sleep quality (OR:1.23; CI:1.15-1.31) were associated with RRIs, as were perceived health (OR:0.96; CI:0.94-0.97), running over 20 km/week (OR:1.58; CI:1.04-2.42), overweight (OR:2.17; CI:1.41-3.34), pes planus (OR:1.80; CI:1.12-2.88), hard-surface running (OR:1.37; CI:1.17-1.59), running company (OR:1.65; CI:1.16-2.35), and following a training program (OR:1.51; CI:1.09-2.10). These factors together explained 30% of the variance in RRIs. A separate regression analysis showed that mental aspects and sleep quality explain 15% of the variance in RRIs. The association of mental aspects and sleep quality with RRIs adds new insights into the multifactorial etiology of RRIs. We therefore recommend that besides common risk factors for RRI, mental aspects and sleep be incorporated into the advice on prevention and management of RRIs.
Role of Supervising teachers in the implementation Teaching Improvement at MAN 1 Padangsidimpuan
Authors: Nurkhoiriyah Siregar Saiful Akhyar Lubis,
Published: March 2021

This study aims to reveal: 1) The activities carried out by the supervising teacher in carrying out the diagnosis of student learning difficulties as preparation for implementation in teaching improvement at MAN 1 Padangsidimpuan, 2) Activities carried out by the supervisor in providing repair assistance ( remedial teaching) in MAN 1 Padangsidimpuan, and 3) Activities carried out by the supervising teacher in the assessment and follow-up of the implementation of teaching improvements at MAN 1 Padangsidimpuan. This research uses a qualitative approach, phenomenological research type, and descriptive analysis method. Data collection techniques are carried out by; participatory observation, in-depth interviews, and document analysis. The data analysis process was carried out starting from; data reduction, data presentation, and conclusions. Test the validity of the Data with credibility, transferability, dependability, and confirmability. The results of this study are: 1) Diagnosis of student learning difficulties in preparation for improvement teaching activities is carried out through four stages, namely identification of students, identification of locations and types of learning difficulties, determining factors causing learning difficulties and planning assistance, 2) Implementation of teaching improvement is carried out by counseling teachers. through the implementation of assistance, where this activity is directed at giving assignments, providing learning services related to learning methods and habits, learning motivation and interest in learning services, and 3) The efforts made by the supervisors in the implementation of teaching improvements, especially concerning assessment and follow-up are carried out continuously together through coordination and discussion between BK teachers and subject teachers.
Global actors in Central Asia: Great Game or Great Gain?
Authors: AUBAKIR Assima
Published: March 2021

From the first days of their independence, the Central Asian states were constantly searching for the most optimal and beneficial ways to interact between each other and with other partners, both located in close proximity to their borders and relatively remote, but no less significant.
The main goal and scientific novelty of this research is to analyze current approaches, taking into account the foreign policy doctrines of global actors (Russia, China, the USA and the EU) in relations with the countries of Central Asia. Particular attention is paid to the assessment and conclusions on the prospects for their development, including through the prism of the interests of the states of the region.
The Analysis of Zimbabwe`s informal Sector`s Economic Sustainability Subject to Lockdown Effects
Authors: Tarupiwa Tafadzwa Telmore
Published: March 2021

Zimbabwe`s economic society had been dominated by the informal sector as the main source and substitute for formal employment. It comprises of vendors, crosses border traders, cottage industries, artisanal miners and many others conducting lawful but unregistered economic activities. Given it being seen as a new normal for Zimbabwe`s economic structure, the 2020 national lockdown necessitated the analysis on the economic sustainability of Zimbabwe`s informal sector given the hardship experienced. Applying extensive literature review, content analysis and critical assessment of theory and practice as the methodology, the informal sector is deemed highly unsustainable economically. This paper proposes a total restructuring of Zimbabwe`s sector structure, through the creation of a total development strategy that enables refocusing government expenditure and policy towards realignment of informal structure to formal. Furthermore, this paper advocate for a balanced development strategy, that incorporates all sectors which accelerate growth and a stable formal sector through technological innovations and modernisation such that there is technology transfer to the informal sector, as opposed to arbitraging and vending activities as they are prone to stagnation and vulnerability.
Policy Transfer: A Classification of the Extant Literature into Waves, A Critique of the Existing Waves and A Proposal for a New Wave
Authors: Benson Lucky
Published: March 2021

This paper presents a critical review of the extant literature on policy transfer. The aim is to classify transfer literature into waves, highlight the problems with the existing waves and propose a new wave that addresses the limitations in the extant literature. The purpose is to make theoretical contribution to the literature on policy transfer especially in the areas that the existing waves have ignored. The first part of the paper is organised around concepts associated with the extant literature on the first wave of policy transfer. The focus is on the work of Rose (1991, 1993) on lessons drawing as a driver to Dolowitz and Marsh (1996, 2000) famous literature on policy transfer. This is then followed by the second wave of policy transfer literature. The focal point of the second wave is a critique of the literature on the first wave of policy transfer. Following on for this second wave of policy transfer literature is a new wave that addresses the problems raised in the extant literature on the first and second waves of policy transfer. This is important because it provides the opportunity to cover the limitations of the first and second waves literature on policy transfer and make theoretical contributions.
Radiographic pathologies associated with third molar teeth in Polish population: A retrospective study
Authors: Górski Bartłomiej , Poszytek Daniel , Wojtasiak Sebastian , Górska Renata , Wysokińska-Miszczuk Joanna
Published: March 2021

Introduction

There is a plethora of pathologies that might be associated with the presence of third molar teeth (M3s). In the following study, the impact of M3s status on the occurrence of radiographic lesions of adjacent second molars (M2s) was evaluated.

Materials/Methods

A total of 1,988 panoramic radiographs were included in the statistical analysis. M3s were categorized as non-impacted (N-M3s) or impacted (I-M3s). I-M3s were subsequently divided into partially or completely impacted. Radiographic lesions in the second molars area, such as caries, external root resorption (ERR), and alveolar bone loss (ABL) were assessed. For the purpose of statistical analysis, the level of significance was set at 0.05.

Results

Among all evaluated panoramic radiographs, 1,621 (81.13%) showed at least one N-M3, 535 (26.78%) at least one partially I-M3, and 344 (17.2%) at least one completely I-M3. In the presence of M3s, the frequency of caries, ERR and ABL was determined at 17.98%, 0.68% and 23.96%, respectively, with the odds ratio (OR) for the occurrence of the above-mentioned pathologies at the level of 1.23, 6.97 and 1.31. Notably, the presence of N-M3s particularly increased the odds of caries, while I-M3s significantly increased the odds of ERR and ABR (ORs = 1.42; 26.0; 2.36, respectively).

Conclusions

The presence of M3s, irrespective of their impacted or non-impacted status, increases the risk of pathologies in M2s. Therefore, prophylactic extraction of M3s or active surveillance of patients could be recommended.