bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent changes in boreal aapa mires indicated by CPIsnow model and Landsat time series
Authors: Sallinen Antti , Akanegbu Justice , Marttila Hannu , Kumpula Timo , Tahvanainen Teemu
Published: March 2020

 Patterned fens (aapa mires) are important part of boreal landscape. Their distribution is controlled by climate and local hydrological conditions. In order to assess the changes and stresses climate change and land use may cause in these ecosystems, we modelled the past and future hydrology of twelve aapa mires in different parts of Finland. The study area extends from the southern to northern boreal zone.

Mire catchments were delineated with the help of a digital elevation model. Wet minerotrophic areas (flarks) in the centers of aapa mires were traced from aerial images with numerical methods. Runoff modelling was done for the period 1962–2099 with a conceptual model ‘CPI snow’ using gridded temperature and precipitation data from historical weather records as well as predicted values based on climate scenarios.

The results clearly indicate changes in hydrological conditions of aapa mires. In particular, timing and volume of spring peak runoff after snowmelt are affected. It is probable that the changes influence aapa mire wetness, vegetation, and eventually survival and distribution. We search for evidence of these changes from remote sensing time series (Landsat) from 1980s to present. Possible implications of changes in northern peatlands include loss of biodiversity and changes in carbon cycle.
Sensitivity of simulated warm conveyor belt associated with an extratropical cyclone to model resolution and treatment of cloud processes - a NAWDEX case study
Authors: Choudhary Anubhav , Voigt Aiko
Published: March 2020

Previous work showed that simulations of extratropical cyclones and their intensity are significantly impacted by model resolution. This might be explained by the impact of resolution on cloud diabatic processes occurring within the warm conveyor belt (WCB), as these are linked to the strength of cyclones. To investigate this link, we move gradually from very coarse (80km) to very fine resolution (2.5km) simulations and study if there is a systematic impact of resolution on the simulated WCB processes. For this purpose, we analyse ICON simulations in a regional North Atlatnic setup for a specific case from the NAWDEX campaign -  cyclone Vladiana - that occurred on 23rd September, 2016. Furthermore, we compare simulations with 1- and 2- moment cloud microphysics and with explicit and parametrized convection. From these simulations WCB trajectories are calculated over 48 hours by means of the Lagranto tool and 1-hourly model output to sample cloud diabatic processes within the WCB. We find a systematic increase in the number of WCB trajectories with finer resolution, which also ascent higher. Moreover, the fine-resolution simulations show a new class of anticyclonic trajectories that is absent in the low-resolution simulations. This effect becomes more pronounced when convection is represented explicitly, but is not strongly affected by the treatment of cloud microphysics. We diagnose the impact of increasing resolution on WCB in terms of changes in processes like updraft velocity, diabatic heating and modification of potential vorticity by total diabatic heating and individual diabatic processes.
Hydrogeologic investigation of groundwater velocity for matrix and conduit in a karst aquifer
Authors: Park Hyemin , Yang Minjune
Published: March 2020

It has been recognized that karst aquifers are a unique hydrogeologic system because of strong heterogeneity originating from their complexity of the karst medium. Most karst aquifers have large ranges of flow distributions due to various types of porosity such as matrix, connected fractures, faults, and conduits developed from dissolution. In this study, we measured groundwater velocities in the Floridan aquifer within the springshed of Silver Springs, FL. Groundwater velocities were measured in situ using passive flux meters (PFMs) and karstic borehole dilution (KBHD). Based on these data and previous tracer tests, we estimated rock matrix and conduit velocities of 0.06 ± 0.02 m/day and 3.05 ± 8.1 m/day. These data were coupled with simple analytical solutions to identify the proportion of the aquifer that contributes most significantly to water flow into the spring with two different modeling scenarios: single domain and dual-domain including matrix and non-matrix zones. The dual-domain scenario suggest that matrix flow contribute approximately 4% of the total flow while non-matrix flow through conduits and fractures contribute approximately 96% of the total flow, even though the non-matrix zones account for only 5.2% of the total aquifer cross-sectional area, within approximately 3 km from the spring outlet (with the upstream capture zone representing approximately 1% of the springshed area (2300 km). The results offer field-measured hydrogeologic data that can be used for active resource management in the springshed and the simple modeling approach presented in this study might be applicable to other springs to estimate the portion of water flows and solute pathways to the spring outlet.
Application of SWAT-MODFLOW Model to Understand How Groundwater Recharge in Sabarmati River Basin is Affected by Extreme Climate Events.
Authors: Sinan Muhammed , Mishra Vimal
Published: March 2020

The interrelation between ground water and surface water has a serious consequence on water management. Groundwater level depletion gradually occurs in high water stress areas when there is groundwater extraction. Here we study the spatial and temporal patterns of surface water and groundwater flow in the Sabarmati Basin. We analyze the effect of groundwater pumping for irrigation purposes on the depletion of groundwater. We also assess the influence of drought and flooding on groundwater recharge in the basin, by modelling the basin in SWAT-MODFLOW for a period of 1901 to 2019. Our results show that the groundwater recharge in Sabarmati basin, which is a part of semi-arid region of India, is significantly affected by hydrological extremes (floods and droughts) during the monsoon (June – September). The insights of our research will help to overcome the grand challenge of water management in a changing climate scenario.
The effect of clay tortuosity on contaminant plume persistence
Authors: kim changmin , yang minjune
Published: March 2020

The presence of contaminated aquitards has been recognized as one of the main obstacles that hamper the successful aquifer restoration and the forward and back diffusion processes were known as the primary mechanism of solute exchange between the aquifer-aquitard system. In this study, a series of 2-D flow chamber experiments were conducted using 1 g/L of bromide solution as a non-reactive tracer to evaluate back diffusion phenomenon and plume tailing behavior based on different clay types (kaolinite, montmorillonite, and bentonite). In order to determine appropriate values for clay tortuosity, simulated effluent concentrations using 1-D analytical solutions were compared to the measured effluent concentrations. The best fits were found with for bentonite, for kaolinite, and The bentonite tortuosity value close to 1 indicates that the solute flowpath is similar to the aquitard straight-line distance under the saturated condition. Simulation results using the calculated tortuosity showed that bromide effluent concentration due to back diffusion from the montmorillonite layer decreased to 3 orders of magnitude below the initial concentration after 60 days of back diffusion. For bentonite, calculated effluent concentrations decreased to 3 orders of magnitude below the initial concentration after 230 days of back diffusion. These results suggest that the aquitard with higher tortuosity has more capability to sustain long-term plume persistence for non-reactive contaminants and more potential risks as secondary contaminant sources.
A new and efficient procedure for dispersive tsunami simulations on spherical coordinates based on a hyperbolic approach
Authors: Escalante Sanchez Cipriano , Castro Díaz Manuel J. , González Vida José Manuel , Macías Sánchez Jorge , Lorito Stefano , Romano Fabrizio
Published: March 2020

When tsunamigenic events are simulated in deep to moderately deep waters, frequency dispersion effects may become mandatory. In the framework of dispersive systems, non-hydrostatic pressure type models have been shown to be able to describe weakly dispersive waves [2,3]. Although promising results begin to glimpse nowadays, dispersive solvers are still far from being robust, efficient and able to compute on a faster than real-time (FTRT) basis. The main difficulty that presents this type of systems is that at each time step a parabolic-elliptic problem has to be numerically solved and a high computational effort is required.

In [1] a novel weakly non-linear and weakly dispersive system that takes into account dispersive effects is presented. The main advantage is that the system is strictly hyperbolic and that any explicit numerical scheme can be applied to solve numerically the equations.

We will present new numerical results from an upgrade of the system presented in [1], considering curvature effects through a rewriting of the system in spherical coordinates. The numerical results will cover some standard field validation tests involving tsunami propagation waves. Besides, the explicit numerical scheme has been implemented exploiting the power of modern GPU architectures (CUDA). Then, numerical results along with some computational times will show that this numerical model opens a new line on tsunami simulation scenarios, using a new, efficient and accurate procedure to produce FTRT tsunami propagation including dispersive effects.

Acknowledgments: This research has been partially supported by the Spanish Government Research project MEGAFLOW (RTI2018-096064-B-C21), Universidad de Málaga, Campus de Excelencia Internacional Andalucía Tech and ChEESE project (EU Horizon 2020, grant agreement Nº 823844), https://cheese-coe.eu

[1] C. Escalante, M. Dumbser, M. Castro, An efficient hyperbolic relaxation system for dispersive non-hydrostatic water waves and its solution
with high order discontinuous galerkin schemes, Journal of Computational Physics 394 (2019) 385 – 416.

[2] C. Escalante, T. Morales, M. Castro, Non-hydrostatic pressure shallow flows: Gpu implementation using finite volume and finite difference
scheme, Applied Mathematics and Computation (2018) 631–659.

[3] Y. Yamazaki, Z. Kowalik, K. Cheung, Depth-integrated, non-hydrostatic model for wave breaking and run-up, Numerical Methods in Fluids
61 (2008) 473–497.
Analysis of Spatio-temporal Variation on Water Quality using a Statistical Markov Process with the Unobservable States
Authors: Cho Hemie , Yu Jae-Ung , Uranchimeg Sumiya , Kwon Hyun-Han
Published: March 2020

The mechanism of the water pollution process is becoming more complex due to changes in climate and river environment. There has so far been little effort to explore uncertainty considering these factors in water quality management. The water quality of rivers in Korea has become an issue and even led to a socio-political problem, especially after the environmental changes caused by the development project. We used a machine learning based classification apporoach to investigate the overall pattern of water quality changes over the past 16 years including the construction period. Water quality models are commonly based on a numerical-based deterministic model that has limitations representing stochastic behaviors properly. We employed a statistical Markov process approach to classifying the states of water quality within an unsupervised learning framework. Consequently, the spatio-temporal transition of water quality was accurately identified, and a discussion of the potential causes of the transition is offered.

 

KEYWORDS: Classification, Hidden Markov chain model, Water quality

 

Acknowledgement

This work is supported by the Korea Agency for Infrastructure Technology Advancement(KAIA) grant funded by the Ministry of Land, Infrastructure and Transport (Grant 19AWMP-B121100-04)
Improvement of satellite-based land surface temperature estimation
Authors: kim Seoyeon , lee Yangwon
Published: March 2020

Land surface temperature is crucial in many field of study, such as Earth's surface water cycle, energy balances, energy exchange of ecosystem and  global climate change. As the role of LST is important, it should be accurately obtained on a global scale. However, it is still difficult to calculate LST from satellite because there are constraints of Atmospheric correction, cloud effect, verification representatively. Therefore, the goal is to improve and optimize the accuracy of LST estimates in satellite-based measurement by mixing various data such as multi-spectral thermal infrared image, hyperspectral thermal infrared image, microwave satellite image, etc., or comparing and applying many LST calculation methods and algorithms.
Deep learning-based prediction of fish catch for the offshore waters in south korea
Authors: yoon You jeong , lee Yang won
Published: March 2020

Recently in Korea, the fish catch of offshore waters recorded less than 1 million tons in 44 years due to climate change and drastic changes in the fishing environment. Therefore, it is essential to produce and provide accurate fishing forecast information, such as the location of fishing fields and the amount of fish production, that varies in time and space according to fishing conditions to enhance the competitiveness of the fishing industry. Since the factors affecting the fish catch have various and nonlinear relationships, so this study predicted the catch based on deep learning. The study was selected as the three major fish species of the Korean coast -- anchovy, mackerel and squid. The research area was selected as four fishing area. (One fishing area is 14 km * 14 km). In order to produce accurate forecasted fishing information, it is necessary to identify major marine weather and biological factors affecting the fish catch by fish species and artificial intelligence modeling using marine and weather satellite images. The satellite data used in the study are from the Korea Meteorological Administration (KMA). So far, research on the relationship between two or more factors and fish catches has been insufficient in the previous research, so this study may contribute to the prediction of fishing trends.
Deficit irrigation and the reuse of reclaimed water as strategies to cope with water scarcity in perennial crops. A summary of long-term trials within the H2020 SHUI project
Authors: Intrigliolo Diego , Nicolas Emilio , Pedrero Francisco , Nortes Pedro , Alarcón Juan José
Published: March 2020

In arid and semi-arid regions, restriction on water for agriculture is fostering the search of alternative water resources, such as the reuse of reclaimed water (RW), and water-saving techniques, such as regulated deficit irrigation (RDI) strategies to cope with forecasted food production requirements. Two long-term experiments carried out by the CEBAS-CSIC team offer two scenarios: 1) Intensive cultivation of citrus in coastal areas and 2) extensive grape production for wine making in inland areas of Spain. Experiments in the Murcia Region (Spain) studied the physiological and agronomic effects of irrigating a young commercial grapefruit orchard with two water sources (saline RW versus conventional water). Water transferred from an irrigation canal (TW; electrical conductivity, EC≈1.3 dS m−1) and RW from a wastewater treatment plant (EC≈3.0 dS m−1) were compared, with control irrigation supplying 100% of the crop evapotranspiration (ETc) while the RDI treatment was irrigated at 50% of ETc during the 2nd stage of fruit growth Although the RDI treatment decreased annual irrigation volume by 13.2%, soil salinity substantially increased in summer in the RDI treatment While these treatments did not negatively affect vegetative growth, yield and fruit quality, trial duration (2008-2010) was short in relation to the commercial life of a citrus grove, requiring further research over a longer term. This highlights the need for a longer-term socio-economic analysis that is possible within projects of SHui’s duration (2018-2021). In grapevines research initiated in 2012 continues within SHui, to explore the effects of applying two different strategies: a) RDI in comparison with rainfed conditions and a full irrigation control. During the first three seasons (2012-2014), SDI was the preferred strategy to substantially improve yield (by 49%) compared to the rainfed regime, thereby significantly increasing water use efficiency (calculated considering both precipitation and irrigation). However, yield increments at 100% ETc were offset by detrimental effects that full irrigation had on grape composition. In this case, 8 years of these irrigation treatments produced similar results to the first three seasons of water application, suggesting cost benefit analyses of different deficit irrigation treatments over 3 may provide useful results to inform farmer choice
Consumer as a source of marine litter: Eye-tracking research in Baltic Sea coastal area
Authors: Razbadauskaite Venske Indre , Dailidiene Inga , Dailide Remigijus , Kondrat Vitalijus , Baltranaite Egle , Dabulevičienė Toma
Published: March 2020

This part is one of the research components for the Ph.D. thesis of geographical sustainable consumption which analyzes the influence of daily household waste causing a significant increase in marine litter. According to the "Marine Litter Socio-economic" study typical items founded on urban beaches usually are bottle caps, plastic bags, plastic food containers, wrappers, and plastic cutlery. In general, 48% of marine litter is caused by household-related waste and 70% of marine litter are plastics in the Baltic Sea (UN Environment, 2017; Helcom, 2018ad).

The main aim of this socio-economic research part is to investigate consumer as a source of marine litter in the Baltic Sea (pilot: Lithuania). It combines both qualitative and quantitative methods. Eye-tracker assists in the analysis of gaze points data which is collected on the beach photos with marine litter (focus on macro litter). Semi-structured interviews provide more in-depth insights about consumer behavior and habits. 

Thus, the main goal of this research is to find out and introduce awareness-raising activities among consumers that minimize marine litter and prevent waste generation behavior. To sum up, it is interdisciplinary research that combines three different areas: physical geography, environmental protection, and marketing with a special focus on consumer behavior.
Magmas of the El Quemado Complex (Chon Aike Silicic Igneous Province, Patagonia): Elevated Oxygen Isotope Signatures Across Space and Time
Authors: Foley Michelle , Putlitz Benita , Baumgartner Lukas , Guillermin Zoé , Bégué Florence
Published: March 2020

The generation and source of ~230,000 km3 of total erupted volume of the predominately silicic (>90 %; Pankhurst et al., 2000) magmas which comprise the Jurassic Chon Aike Large Silicic Igneous Province (CASP) of Southern Patagonia is currently debated. In this study, we conducted a widespread sampling of multiple eruptive units, primarily ignimbrites and minor rhyolitic flows, along the Eastern Andean front (~47°S to 49°S), owning to the third and youngest eruptive episode of the CASP (El Quemado Complex; EQC). To determine the magmatic source and potential role of a significant crustal contribution proposed in the generation of these magmas, we analyzed the in-situ δ18O composition of both quartz and zircon by SIMS. We combined these data with LA-ICP-MS U/Pb analyses on single zircon crystals to characterize the potential for changing oxygen isotopic values through time and space within the EQC units along this ~230 km long transect.

The northern-most units sampled have the lightest average δ18O (relative for the EQC) analyzed in zircon and quartz (7.7 and 10.4 ‰, respectively). Oxygen isotope values increase towards the South, with the highest δ 18O values previously reported in El Chaltén, reaching up to 10.1 ‰ for zircon and 12.5 ‰ for quartz (Seitz et al., 2018). Eruptive units from the same locality appear to be homogeneous in their oxygen isotopic composition.

U/Pb zircon ages for the EQC range overall from ~148 to 155 Ma, though no obvious trend from North to South in zircon crystallization ages is noticeable. Multiple inherited zircon cores (at ~230, 460, 500, 1300 Ma) with Jurassic magmatic overgrowths were discovered. Isotopic compositions of these inherited magmatic cores are variable in their δ18O values throughout time. However, and more significantly, most of these inherited cores record high δ 18O values, with the highest value at 9.5 ‰ measured for a ~460 Ma core. These high values measured within inherited cores are found at all locations sampled for the EQC.

The δ18O values of the EQC rocks are significantly higher than what would be expected for silicic magmas formed by simple closed-system fractionation from any mantle-derived melt (6­-7‰; Valley, 2003). Thus, our oxygen isotope data support significant input of crustal material - of either a sedimentary origin or from hydrothermally altered crust - to generate these ignimbrites and rhyolites with elevated δ18O values all along this transect.
A Hierchcial Bayesian Model for Spatio-Temporal Water Quality Modeling in a Chainging Climate in South Korea
Authors: Jung Minkyu , Choi Hong-Geun , Nguyen Dinh Huy , Kwon Hyun-Han
Published: March 2020

Contaminants that cause water pollution are generated from large areas and flow into rivers. It becomes difficult to obtain an accurate prediction of water quality due to the large spatio-temporal variability in a changing climate which in turn leads to considerable uncertainty in the estimation of water quality. Water quality over South Korea highly depends on hydrometeorological conditions due to distinct seasonality. In this context, we explored the use of hydrometeorological variables (i.e., precipitation and temperature) and the autocorrelation structure of water quality parameters in the water quality prediction model within a Bayesian modeling framework. More specifically, we analyzed explored the interdepedencies and correlations between hydrometeorological factors and the water quality parameters for the Mangyeong River basin, and built a hierarchical Bayesian regression model for the TN and TP which are main water quality paramters in South Korea. The result shows that the proposed modeling framework can capture the key aspects of the water quality paramters in terms of seasonality and their uncertainty.

 

KEYWORDS: Hierarchical Bayesian Model, Meteorological factors, Water Quality prediction

 

Acknowledgement

This work was funded by the Korea Meteorological Administration Research and Development Program under Grant KMI(KMI2018-01215)
How fault creep makes its way!
Authors: Ray Sohom , Garagash Dmitry
Published: March 2020

We model mechanics of an aseismic fault creep propagation and conditions when it may lead to the initiation of seismic slip. We do so by considering fault bounding medium to be elastically deformable and fault's interfacial strength to be slip rate- and state-dependent characterized by the steady-state rate-weakening. The fault is considered to be initially locked: a state of slip when interfacial slip velocity is considerably low and arbitrarily less than the steady-state sliding rate for given uniformly distributed prestress.

We find solutions for creep penetration into the fault under geologically relevant loading scenarios (e.g., that of a plate-bounding strike-slip faulting driven by the slip at depth, or that of a rate-weakening patch of a fault loaded by a creep on an adjacent rate-strengthening part due to, e.g., anthropogenic fluid injection). In all the cases, the creep makes its way as a self-similar traveling front characterized by high stress owed to the direct effect; however, the remaining creep profile exhibits a near steady-state sliding. This may imply that a choice from a set of rules for the evolution of state variable—with identical linearizations about steady-state sliding—has no bearing on the creep penetration. Further, we find that the prestress, close to or far from steady-state sliding stress, controls the rate and manner of the creep penetration.

We study slip propagation from an imposed dislocation accrued at a constant rate at one end of a homogeneous fault with the other end either at (1) the free surface of an elastic half-space or (2) strictly locked (buried) in the elastic full space. In both scenarios, no slip instability takes place over aseismic creep propagation distances relatable to the usual elasto-frictional nucleation lengthscale (e.g. Rubin & Ampuero 2005). Instead, in the first case creep propagation leads to the nucleation of the first and all subsequent dynamic events of the emerging cycle at/near the free surface after the creep traversed the entire length of the fault. In the second case, the creep front traverses nearly the entire length of the fault, but, instead of nucleating a dynamic event, the front arrests at some distance from the buried fault end, followed by the continual accumulation of aseismic slip without ever nucleating a dynamic event. These results may be owed to the physical and geometrical invariance of the considered homogeneous fault and may signal the essential role of fault strength heterogeneity, either that of the normal stress and/or frictional properties (Ray & Viesca, 2017, 2019), in defining its seismogenic character, i.e. under which conditions and where on the fault the earthquake slip instability can take place. 
Development of a high-resolution air quality forecasting system, based on WRF-Chem model, for the greater area of Thessaloniki, Greece
Authors: Zyrichidou Irene , Solomos Stavros , Kotsopoulos Stylianos , Syropoulou Panagiota , Kosmidis Evangelos
Published: March 2020

Air pollution models play an important role in science because of their capability to give a description of the air quality problem including an analysis of factors and causes (emission sources, meteorological processes, and physical and chemical changes). Real-time forecast of urban air quality is highly important to the public as advanced information for both air quality and safety assessment. This study presents the development of a regional scale high-resolution modeling system for simulating air quality and forecasting changes in urban pollution levels. The air quality system based on the state-of-the-art Weather Research and Forecasting model coupled with chemistry (WRF-Chem) has been applied over the greater area of Thessaloniki, Greece. The model performance, in terms of simulated surface major air pollutants’ concentrations, is evaluated using ground-based measurements during the operational implementation period in winter-spring 2020. Our study highlights the importance of resolving local scale atmospheric conditions such as surface wind flow and boundary layer properties for describing the pollutants’ concentrations and the importance of constraining emissions over the study area.

 
Dating of impure carbonates – Utilizing laser ablation MC-ICPMS to reconstruct initial 230Th/232Th ratios
Authors: Förstel Julius , Warken Sophie , Schröder-Ritzrau Andrea , Frank Norbert
Published: March 2020

Uranium series dating is a valuable and well-established tool for age determination of carbonates in paleoclimatology. However, detrital contamination can alter results. A correctional term is commonly used to account for additional Th introduced into the sample material as detritus. This correction requires to make assumptions about the initial 230Th/232Th ratio of the detrital material, since it is not possible to extract it from an individual measurement. Laser ablation multi collector ICPMS equipped with multiple ion counting detectors offers the possibility to use an isochrone technique to extract the initial 230Th/232Th value from heterogeneous samples with a high detrital content. This decreases systematic errors and uncertainties introduced by the detrital correction term and therefore improves the possibility of dating impure carbonates.
Analysis of temporal variations of Cs-137 discharge inventory from the port of Fukushima Daiichi Nuclear Power Plant over 9 years after the accident
Authors: Yamada Susumu , Machida Masahiko , Iwata Ayako , Otosaka Shigeyoshi , Kobayashi Takuya , Watanabe Masahisa , Funasaka Hideyuki , Morita Takami
Published: March 2020

Just after Fukushima Daiichi Nuclear Power Plant (1F) accident occurred in March 2011, the direct discharges of highly-contaminated water from reactor Unit 2 and 3 into the 1F port followed. After the suppressions of the direct discharges, Kanda (Biogeosci. 10, 6107–6113, 2013) suggested that relatively small amounts of run-off of a radionuclide (Cs-137) from 1F port into Fukushima coastal region has continued based on his estimation method. However, Kanda’s estimation period was limited up to September 2012. Therefore, we expand the estimation period of the discharged inventory up to very recently, March 2020 with significant accuracy improvements by the present authors. As a result, we find that totally, in the period over 9 years, the discharged inventory has gradually diminished together with various characteristic fluctuations. In this presentation, we analyze the observed diminishing trends with temporal fluctuations and discuss their relationships with various suppression measures and constructions toward decommissioning of 1F. Furthermore, we estimate the annual discharged amount of Cs-137 and evaluate its impacts on the coastal area in terms of seawater concentrations.
Terrestrial and Martian Dust Devils: study of the translational motion and resolution of the size/distance degeneracy of the meteorological time series
Authors: Franzese Gabriele , Silvestro Simone , Vaz David , Popa Ciprian , Esposito Francesca
Published: March 2020

Dust devils are convective vortices able to lift sand and dust grains from the surface. They are common not only in the terrestrial deserts, but also on Mars, where they give a substantial contribution to the planetary dust budget (∼50%). Dust devils are characterized by a central pressure drop that generates the rotation and translate advected by the wind background.
One of the problems related to their monitoring is due to the impossibility to directly separate the translational and rotational motion components from the study of the wind speed and direction time series. This means that it is not possible to directly retrieve information on their translational speed and direction and on the maximum rotational wind speed using only a meteorological station. 
In addition, there are other fundamental parameters that are not directly measurable, such as the distance of passage of the vortex from the station, its sense of rotation and its diameter.
These limitations lead in general to a size/distance degeneracy of the results, i.e. the acquired meteorological signatures of a smaller dust devils passing near the station could not be distinguished from the ones of a bigger and farther event. This, in turn, leads to several problems in the study of their physics.
To avoid these issues, the monitoring meteorological station can be equipped with an imaging camera system with a sufficient acquisition rate, resolution and field of view. However, this is not always possible, in particular for the planetary space missions.
Here, we want to present two simple methods for the characterization of the wind speed and direction time series of dust devils that allow an easy solution for the measure of the vortex translational wind speed and direction, distance of passage and sense of rotation.
The knowledge of these parameters allows to completely characterize the measured dust devils encounter just using the meteorological station acquisition.
In order to test the methods, we performed a field campaign in the Sahara desert, deploying a fully equipped meteorological station coupled with a camera system. We compared the results of the meteorological analysis with the ones obtained from the images, confirming the effectiveness of our methodology.
This methodology can give a substantial improvement in the interpretation of the past and next martian dust devils data. For example, the ESA/Roscosmos ExoMars 2020 mission will host on its lander a meteorological station (METEO package) and the Dust Complex, a suite of specific instruments devoted to the study of the primary airborne dust. These instruments can be used in tandem for the characterization of the local dust devils activity.
Thermophysical reservoir properties of the Hauptdolomit-facies underneath the Viennese basin across fault zones analogues – a reservoir study for the GeoTief EXPLORE project
Authors: Rupprecht Doris , Fuchs Sven , Förster Andrea , Penz-Wolfmayr Mariella
Published: March 2020

The GeoTief EXPLORE project aims to explore the geothermal potential and quantify the geothermal resources of the Vienna Basin (Austria) and the underlying Northern Calcareous Alpine basement. The main target of geothermal interest is the massive and tectonically remolded Hauptdolomite facies that has been identified as potential geothermal reservoir in previous studies. Now, this formation is studied using outcrop analogues for the investigation of their petrophysical characterization and specific thermal properties (thermal conductivity and thermal diffusivity).

 

Here, we report new measurements on a total of 60 samples from 6 outcrops in and around the area of Vienna applying different methods for the laboratory measurement of thermal and hydraulic rock properties. The petrophysical analysis considers the impact of deformation along and across fault zones, which introduces heterogeneity of storage properties and consequently in the thermophysical properties. Using the standard fault core and damage zone model, outcrop samples were grouped into unfractured and fractured protoliths, as well as in fault rocks, like breccias and cataclasites. Rock samples are then classified by their fracture density (m² fracture surface per m³ rock) and by their matrix content and differences in grain sizes, respectively.

 

The measured thermal rock properties vary significantly between the selected rock groups. The total range [90 % of values] is between 3.2 and 5.0 W/(mK) for thermal conductivity and between 1.3 and 2.7 mm²/s for thermal diffusivity. The results generally met the expected trend for fractured rocks as conductivity and diffusivity decreases with increasing porosity under unsaturated and saturated conditions. The total porosities are less than 5%. The variability of thermal conductivity under saturated conditions shows complex trends depending on the different rock classifications where fault rocks and highly fractured rocks of the damage zone show lower increase in thermal conductivities.

 

The new petrophysical characterization will be the base for further numerical investigations of the hydraulic and thermal regime as well as for the analysis of the geothermal resources of the Hauptdolomite.

 

 

 

 
Understanding the Origin of Variable Compositions of Gradual Solar Energetic Particle Events by Combining Observations and Numerical Simulations
Authors: Nitta Nariaki , Jin Meng , Cohen Christina
Published: March 2020

One of the mysteries of solar energetic particle (SEP) events is the compositional variability in those events that are clearly shock-related and may be called gradual events.  In particular, the reason for the enhancement of Fe with respect to O or C at high energies has been debated over the past two decades, and yet it is still unsettled.  One hypothesis relates the compositional variability with whether the CME-driven shock is quasi-parallel or quad-perpendicular near the Sun, but this may not be easily tested using remote-sensing data alone. In recent years, however, CME-driven shock waves have been modelled by fitting shock-like features in EUV and white-light images with relatively simple shapes, and in combination with magnetic field models, ir is possible to compute shock parameters at the shock surface. In this presentation, we simulate a few CMEs whose associated SEP events show widely different Fe/O, using the Alfven wave Solar Model (AWSoM) that is part of the Space Weather Modeling Framework (SWMF). We constrain the input parameters of the simulations so that the observed pre-eruption corona, eruption and CME are well-reproduced. The shock surface, across which the shock parameters are highly non-uniform, is carefully traced, and the time-dependent connectivity of the shock surface with the observer at multiple spacecraft is compared with the SEP properties including composition. We discuss how much about the compositional variability of SEP events can be learned with this technique.
Assessment of the CORDEX-CORE Africa simulations: evaluation and uncertainties in the mean and extreme indices climate change signal
Authors: Abba-Omar Sabina , Raffaele Francesca , Coppola Erika , Jacob Daniela , Teichmann Claas , Remedio Armelle
Published: March 2020

CORDEX-CORE is a new phase of CORDEX simulations with higher resolutions (0.22 degrees) consisting of two RCMs forced by three GCMs. This higher resolution ensemble could provide added value to regional climate change information, however, since the data has just recently been released, more studies are required to validate and report on its climate change signal. With this in mind, we computed the mean climate and extreme indices over Africa using the CORDEX-CORE ensemble. These results are compared to the results of  the driving models as well as to the lower resolution CORDEX-phase 1 ensemble. We found that for most of the extreme indices the CORDEX-CORE shows lower biases over Africa owing to its higher spatial resolution. We also found that the mean climate change signal over Africa was broadly consistent across the three different ensembles. Indicating that the new CORDEX-CORE ensemble is able to capture the uncertainty spread well. We report the projected changes in extreme indices over Africa found in the new higher resolution CORDEX-CORE ensemble. We also examine and compare the representation of some key dynamical features over Africa in the different ensembles. Africa is especially vulnerable to extreme events, due to its limited capacity for disaster management. Thus, this study adds important, higher resolution information to the existing climate change impact knowledge for Africa. 
Piping in practice: Incorporating natural subsurface variability into backward erosion models
Authors: Winkels Tim , Dirkx Willem Jan , Cohen Kim , Middelkoop Hans , van Beek Rens , Bierkens Marc , Stouthamer Esther
Published: March 2020

River embankments form an essential part of the primary flood defence in the Netherlands. Of all failure mechanisms, piping is considered one of the key mechanism for triggering dike destabilization of river dikes in Rhine-Meuse Delta. Within the STW project Piping in practice, we aim to better understand 1) the influence of variability within subsurface characteristics on the piping process, and 2) the natural variability of these subsurface characteristics underneath embankments in the Rhine-Meuse delta.  
We employ the lithogenesis of sandy deposits to group variability in subsurface parameters across different scales. Using extensive borehole datasets, we quantified regional trends within and between geological units in order to investigate geological controls on variability these subsurface properties. On a smaller scale, laboratory experiments have shown that larger variation in grain size or layering in porous media have a retarding effect on the progression of small-scale pipes, demonstrating the importance of incorporating these variabilities into the piping assessments.  Combining laboratory experiments and field observations, representative sedimentary architectures are implemented into digital piping models at several embedded scales. This will allow us to better describe subsurface variability in terms of model parameters, and improve computation of the piping process.
Remote sensing data and field survey activities for monitoring the evolution of forest systems after coppicing and soil erosion: A case study in Sardinia (Italy)
Authors: Giadrossich Filippo , Ganga Antonio , Campus Sergio , Murgia Ilenia , Piredda Irene , Lovreglio Raffaella , Di Prima Simone , Pirastru Mario , Scotti Roberto
Published: March 2020

The practice of coppicing is debated in the literature for the risk factors associated with soil erosion. Although erosion experiments provide useful data for estimating the susceptibility to soil erosion, there are many open questions that cannot be solved in isolated experiments, but which can be assessed by activating a long-term monitoring process. In this way, it is possible to correctly frame the spatial and temporal scale of soil erosion in coppice forests. 

The aim of the work is to evaluate the effectiveness of the use of remote sensing data in combination with field data, for monitoring the evolution of forest stands interested by coppicing in relation to soil erosion. 

We have installed a long-term monitoring network for erosion estimation, while Sentinel-2C satellite data were used for the period 2016-2018. Starting from this dataset, a selection of vegetation indices was calculated and compared to the morphological and topographical parameters of the study area, as well as the above-ground data collected during field activities. Using the Canonical Correspondences Analysis (CCA) the relationships between the matrix of vegetation indices, topographic and vegetational parameters and the respective performances of this protocol have been explored in order to describe the evolution of the forest stands in the study area associated to soil losses.
Automatic monitoring of crustal seismic activity in Galati region of southeastern Romania using full waveform-based approach
Authors: Tataru Dragos , Poiata Natalia , Grecu Bogdan
Published: March 2020

In September–November 2013 a seismic swarm occurred in Galati region of southeastern Romania. The area was previously known as characterized by low seismic activity along the major crustal faults. During the period of swarm, between September 23rd and November 5th, over 1000 events with the magnitudes (Ml) of 0.2–4.0, located at the depth of 5–10 km, have been detected. Despite the relatively small magnitude, events generated ground motions that were well felt by local people, leading to panic in the area. The proximity of active oil fields caused additional annoyance.

Advanced seismic monitoring in the region started in 2013 with deployment of mobile seismic stations immediately after the beginning of the swarm. Additionally, active seismic measurements were performed in order to characterize the shallow velocity structure at specific sites. Starting from July 2015 new permanents stations were installed in the area marking the beginning of Galati local network development. The routine seismic catalog derived using the acquired data and applying the standard detection and location techniques pointed that area continues to be seismically active, however with low rate of activity and magnitude of events. These made it a perfect study case for development of new advanced schemes for seismic monitoring of the regions with low and complex seismicity aiming on an understanding of the phenomenon underlying the 2013 seismic swarm as well as the current seismic activity in the area.

We developed and automatic monitoring scheme based on the network-based full waveform detection and location method BackTrackBB (Poiata et al. 2016) that exploits the coherency of signals’ statistical features recorded across the seismic network. Once extracted from the flux of continuous data, seismic events are compared against the database of previously detected events using coherency and allowing to identify potential repeaters or multiplets. The earthquake catalog provided by the system starting from 2017 was compared to the routine ROMPLUS catalog of NIEP showing an increase in the number of detected events by the order of 3. We present the details of the implementation and discuss its advantages and drawbacks.
Carbonate Diagenesis in a Sequence Stratigraphic Framework; Case study from Miocene Dam Formation, Eastern Saudi Arabia
Authors: Salih Moaz , Abdullatif Osman , Al-Ramadan Khalid , Bashri Mazin
Published: March 2020

The Miocene Dam Formation in the Al-Lidam area of Eastern Saudi Arabia consists of a succession 

of mixed siliciclastic-carbonate sequences that were deposited during Miocene (Burdigalian) 

times. Stratigraphic equivalents of the Dam Formation occur as hydrocarbon reservoir intervals in 

the Arabian Plate. Reservoir quality of carbonate rocks is controlled by a combination of 

depositional setting and post-depositional diagenetic factors. 

In this study, fifteen lithofacies were identified as they were deposited on a low angle dipping 

carbonate ramp, under supratidal, beach, intertidal and shallow subtidal conditions. Carbonate 

diagenesis has been examined using: thin-section petrography, SEM, XRD and 

cathodoluminescence. These analytical tools have shown that the intertidal lithofacies are 

influenced by extensive meteoric dissolution and minor cementation. Marine diagenesis was 

restricted to beach grainstone and subtidal lithofacies, in the form of aragonite and high magnesium 

calcite cement. Shallow burial conditions were inferred by grain contacts represented by point, 

suture and concavo-convex contacts. Mimetic dolomitization for the whole succession was also 

observed. Three fourth - order, shallowing upward sequences were identified in the study area, and 

they are separated by two sequence boundaries. A clear relation between sequence surfaces and 

diagenetic processes was observed; meteoric diagenesis and dolomitization increases upwards in 

each sequence. Porosity and permeability measurements have shown that the highest values are 

associated with the HST of each sequence, followed by the TST and the LST. The results of this 

study can help in understanding of diagenetic processes, and consequently in developing better 

and more accurate predictions of the porosity and permeability distribution within hydrocarbon 

reservoirs.

 
The Double-ITCZ Bias in CMIP6 Models
Authors: Tian Baijun
Published: March 2020

The double-Intertropical Convergence Zone (ITCZ) bias is one of the most outstanding problems in climate models. This study seeks to examine the double-ITCZ bias in the latest state-of-the-art fully coupled global climate models that participated in Coupled Model Intercomparison Project (CMIP) Phase 6 (CMIP6) in comparison to their previous generations (CMIP3 and CMIP5 models). To that end, we have analyzed the long-term annual mean tropical precipitation distributions and several precipitation bias indices that quantify the double-ITCZ biases in 75 climate models including 24 CMIP3 models, 25 CMIP3 models, and 26 CMIP6 models. We find that the double-ITCZ bias and its big inter-model spread persist in CMIP6 models but the double-ITCZ bias is slightly reduced from CMIP3 or CMIP5 models to CMIP6 models.