bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Flow Connectivity on the Interpretation of Pumping Test Data
Authors: Yetişti Buse , Copty Nadim K , Trinchero Paolo , Sanchez-Vila Xavier
Published: March 2020

Pumping tests are often used for the estimation of subsurface flow parameters. Research has indicated that traditional geostatistical techniques expressed in terms of two-point correlations (i.e., the covariance of flow parameters at two points is only a function of separation distance) may not be adequate to fully represent complex patterns of flow and transport in heterogeneous subsurface systems. To address this issue, the concept of flow connectivity has been introduced to describe how different regions of the aquifer relate to each other. In this study, the impact of point-to-point flow connectivity on radially convergent flow tests towards a well is investigated numerically. A Monte Carlo approach is adopted whereby a large number of heterogeneous aquifer systems with different levels of connectivity (Gaussian, connected high-transmissivity fields, and connected low-transmissivity fields) are synthetically generated and then used to simulate pumping tests. Various test interpretation methods are then used to estimate apparent flow parameters from the time-drawdown curves, and examine how the estimated parameters relate to the underlying heterogeneous aquifer systems. Results indicate that the estimated transmissivity using only drawdown data corresponding to early times is dominated by the point transmissivity distribution in the vicinity of the well. The estimated transmissivity value gradually approaches the geometric mean of the full transmissivity field as a longer time-drawdown dataset is included in the interpretation. On the other hand, the storage coefficient estimated from late drawdown data is strongly sensitive to aquifer point-to-point flow connectivity and the relative locations of the observation and pumping wells. The relations between the estimated storage coefficient and different aquifer connectivity functions are also examined.
City-scale groundwater flow and heat transport modeling in the Milan Metropolitan Area
Authors: Previati Alberto , Crosta Giovanni Battista , Epting Jannis
Published: March 2020

Aquifers beneath big cities are considered a very important resource from an energy and water supply point of view and are increasingly exploited by means of groundwater extraction wells as well as by shallow open- and closed-loop geothermal systems. Moreover, the shallow subsurface of densely populated cities is increasingly hosting underground infrastructures such as tunnels and building foundations. These activities lead to thermal pollution of the shallow urban underground. This phenomenon has already been documented (urban heat island effect) in many cities worldwide with higher ground/groundwater temperatures in the city centers with respect to surrounding rural areas. The local thermal impact of various underground activities has been studied with analytical and local-scale numerical modeling. However, the resulting groundwater thermal regime at the city-scale is yet mostly unexplored.

In this work the effects of anthropogenic heat sources and subsurface infrastructures in the Milan metropolitan area is presented. To this aim a groundwater head/temperature monitoring network was established in 2016. Groundwater temperatures in the city center are up to 3°C higher with respect to less urbanized areas. A correlation between the urban density and the groundwater thermal regime was observed. In order to evaluate the spatial variability of the groundwater temperatures, a detailed analysis based on a 3D FEM groundwater flow and heat transport numerical model was carried out by means of the commercial code FeFlow. First, the variability of hydraulic and thermal properties as from borehole logs was spatialized into the model by means of 3D geostatistical techniques to account for aquifer heterogeneities. Complex thermal boundary conditions were assigned to the model including the effects of different land cover/sealing materials, building foundations, tunnels, shallow geothermal wells and the canal network. The thermal transport model was calibrated against high-resolution time-lapse groundwater temperature profiles and continuous measurements at fixed depth.

The modeling of the current thermal regime of the shallow aquifers was essential to understand the hydrogeological and thermal processes that are relevant at the city scale. The numerical results are a valuable tool to assess the impact of specific heat sources as well as of surface/subsurface infrastructures on the overall thermal regime and to test the long-term thermal potential of ground/groundwater heat exchangers under possible urban development scenarios. Thereby, the proposed approach can support the sustainable development of subsurface infrastructures at the city-scale and the management and assessment of the thermal potential of low enthalpy geothermal resources.
Chlorinated Very Short-Lived Substances: development + evaluation of gridded emissions for global models and on recent emission trends
Authors: Hossaini Ryan , Bednarz Ewa , Chipperfield Martyn
Published: March 2020

Chlorinated Very Short-Lived Substances (Cl-VSLS) are now recognised as a significant source of inorganic chlorine in both the troposphere and stratosphere (e.g. Hossaini et al., 2016, 2019). The most abundant Cl-VSLS are dichloromethane (CH2Cl2), chloroform (CHCl3), perchloroethylene (C2Cl4) and 1,2−dichloroethane (C2H4Cl2), all of which have significant – but poorly constrained – industrial sources. Global surface observations have shown that the tropospheric abundance of CH2Cl2 and CHCl3 has increased significantly in recent years. For instance, the global surface abundance of CH2Cl2 has more than doubled since the early 2000s and in 2018 was ~42 ppt. Despite this, there has been no recent attempt to create a consistent set of gridded Cl-VSLS emissions with which global models can use to study their impacts. Here, we describe and evaluate a new set of gridded time-varying global emissions of CH2Cl2, CHCl3, C2Cl4 and C2H4Cl2, informed by novel bottom-up industrial emission data. The performance of the emission inventories in the TOMCAT chemical transport model are assessed using data from both long-term surface monitoring networks and a range of tropospheric aircraft campaigns. We use the model to quantify regional variability in Cl-VSLS throughout the troposphere and outline further plans for a new model intercomparison effort to examine the impacts of VSLS in the troposphere and stratosphere.
New insights about the processes leading to marine extinction at the K-Pg boundary using a coupled biogeochemical-ecosystem model
Authors: Guillaume Le Hir , fréderic fluteau , Salome Hennequin , Yves Goddéris
Published: March 2020

If most experts agree that the Cretaceous-Paleogene (K-Pg) extinction (66 Ma) resulted from a combination of the Chicxulub impact and of Deccan volcanism, the chain of reactions (Bond and Wignall, 2014) leading to the extinction is not well constrained. 
 
 In the present study, we use the GEOCLIM model to explore extreme perturbations induced by the two events and to investigate processes leading to the marine extinction. This state-of-the-art numerical tool (geoclimmodel.wordpress.com) includes in particular a marine ecological model in which food webs are simulated and marine organisms are sensitive to abiotic factors of their environment. The characteristics of each “species” of marine organisms, such as the tolerance to pH or temperature changes or the efficiency of predation, are randomly fixed to avoid any determinism in the response to the environmental perturbations. 

  The response of the Earth system to the onset of Deccan traps and to the Chicxulub impact is explored by forcing the model with the most recent “eruptive sequences”  (Schoene et al., 2019, Sprain et al. 2019) and with the assumption of a pulse-like degassing (Chenet et al. 2009) sequence over 500 kyrs that includes CO2 and SO2. This new approach allows us to take into account the interplays between the sulfur and carbon cycles on multiple time scales (from year to 105  yrs) and to capture the model sensitivity to the uncertainties in atmospheric emissions (duration, timing, nature of gases, intensity of pulses, intensity of the impact).

  The coupled evolution of the Earth’s climate and oceanic geochemistry during the K-Pg boundary crisis will be presented. Without considering evolution processes, the biotic response (biomass and biodiversity) will be discussed with respect to the ecosystem structure existing before the perturbations. 
Temperature structure of the Andean subduction zone as derived from the 3D geometry of crustal and upper mantle discontinuities
Authors: Tassara Andres , Julve Joaquín , Echeverría Iñigo , Stotz Ingo
Published: March 2020

The distribution of temperature inside active continental margins plays a fundamental role on regulating first order geodynamic processes as the isostatic balance, rheologic behavior of crust and mantle, magmagenesis, volcanism and seismogenesis. In spite of these major implications, well-constrained 3D thermal models are known for few regions of the world (Europe, Western USA, China) where large geophysical databases have been integrated into compositional and structural models of crust and lithospheric mantle from which a thermal model is derived. Here we present a three-dimensional representation of the distribution of temperature underneath the Andean active margin of South America (10°-45°S) that is based on a geophysically-constrained model for the geometry of the subducted slab, continental lithosphere-asthenosphere boundary (LAB), Moho discontinuity and an intracrustal discontinuity (ICD). This input model was constructed by forward modelling the satellite gravity anomaly under the constraint of most of the seismic information published for this region. We use analytical expressions of 1D conductive continental geotherms with adequate boundary conditions that consider the compositional stratification of crust and mantle included in the input model, and the advective thermal effect of slab subduction. The 1D geotherms are assembled into a 3D volume defining the thermal structure of the study region. We test the influence of several thermal parameters and structural configurations of the Andean lithosphere by comparing the resulting surface heat flow distribution of these different models against a database containing heat flow measurements that we compile from the literature. Our results show that the thermal structure and derived surface heat flow is dominantly controlled by the geometry of the thermal boundary layer at the base of the lithosphere, i.e. the slab upper surface below the forearc and LAB inland. Variations on the modeled configuration of the continental lithosphere (i.e. the way on which the geometry of the continental Moho and ICD are considered into the definition of a space-variable thermal conductivity or the length scale for radiogenic heat production) have an effect on surface heat flow that is lower than the average uncertainty of the measurements and therefore can be considered as second-order. The simplicity of our analytical approach allows us to compute hundreds of different models in order to test the sensitivity of results to changes on thermal parameters (conductivity, heat production, mantle potential temperature, etc), which provides a tool for discussing their possible range of values in the context of a subduction margin. We will also show how variations of these models impact on the Moho temperature and therefore in the expected mechanical behavior of crust and mantle in this geotectonic context
A dynamic giant: changes in North Pacific circulation, biogeochemistry, and CO2 over the last ice age
Authors: Rae James , Gray William , Bradtmiller Louisa , Burke Andrea , Gebhardt Holger , Sarnthein Michael , Thornalley David
Published: March 2020

The North Pacific has been thought of as a sleeping giant in Earth’s climate system.  Despite being a major reservoir of heat, nutrients, and carbon, the lack of deep water formation in this region today limits the exchange of these properties.  Here, using a variety of new and published sediment core data, alongside Earth system modeling, we provide evidence that the North Pacific giant is in fact a dynamic player in Earth’s climate system, with active PMOC during the LGM and deep water formation during HS1.  We also demonstrate a persistent Atlantic-Pacific seesaw in deep water formation during rapid climate change events, and discuss the impact of these changes on regional climate and global CO2.
Sea-ice algal phenology in a warmer Arctic
Authors: Tedesco Letizia , Vichi Marcello , Scoccimarro Enrico
Published: March 2020

The Arctic sea-ice decline is among the most emblematic manifestations of climate change and is occurring before we understand its ecological consequences. We investigated future changes in algal productivity combining a biogeochemical model for sympagic algae with sea-ice drivers from an ensemble of 18 CMIP5 climate models. Model projections indicate quasi-linear physical changes along latitudes but markedly nonlinear response of sympagic algae, with distinct latitudinal patterns. While snow cover thinning explains the advancement of algal blooms below 66°N, narrowing of the biological time windows yields small changes in the 66°N to 74°N band, and shifting of the ice seasons toward more favorable photoperiods drives the increase in algal production above 74°N. These diverse latitudinal responses indicate that the impact of declining sea ice on Arctic sympagic production is both large and complex, with consequent trophic and phenological cascades expected in the rest of the food web.
Drivers and outcomes of salt marsh erosion
Authors: D'Alpaos Andrea , Roner Marcella , Tommasini Laura , Finotello Alvise , Ghinassi Massimiliano , Marani Marco
Published: March 2020

Salt marshes are widespread features of tidal landscapes and exert a primary control on the ecomorphodynamic evolution of these environments, delivering valuable ecosystem services. Among the latter, salt marshes furnish a shoreline buffer between the mainland and the sea, dissipating waves and mitigating erosion during storms, filter nutrients and pollutants, serve as an organic carbon sink, and provide diverse ecological habitats.

The sustainability of most of the modern salt-marsh systems worldwide is threatened by increasing anthropogenic pressures, as well as by changes in climate forcings. Particularly, the dramatic decrease in marsh extent, observed worldwide during the last centuries, has long been ascribed to the combined effects of rising relative sea level and sediment starvation. However, even though both those processes may cause the drowning of extensive salt-marsh areas, recent studies have demonstrated that the great majority of salt marshes worldwide are being lost due to the lateral erosion of their margins. If on the one hand the lateral retreat triggered by wind waves is recognized as a primary driver for salt-marsh lateral retreat, on the other hand it still remains questionable whether different local soil properties (e.g., water content, dry bulk density, organic matter content, inorganic grain size) and vegetation cover actively affect the resistance, and ultimately the erosion, of salt-marsh margins.

Here we investigate, by means of numerical modelling combined with field and laboratory analyses, how the interplays between incoming wave power, ecological features, and soil properties influence the erosion rates of salt-marsh margins in the Venice lagoon (Italy).

We show that lateral erosion rates of salt marshes are primarily controlled by the incoming wind-wave power, mediated by the presence of different halophytes, whereas significant influence of soil properties is observed.

Erosion rates are reduced in marsh edges colonized by particular associations of halophytic vegetation species, and along gently sloped and irregular margins facing very shallow tidal flats. Conversely, erosion rates are enhanced in cliffed margins exhibiting smooth planform morphologies, which are typically stricken by strong wind waves.

By clarifying the interactions between the dynamics and functional shapes of salt marsh edges, our observations might be valuable for the conservation and restoration of salt-marsh landscapes, especially in the face of a globally changing climate.
Bridging the science-policy gap in a transition-country setting: enablers and barriers
Authors: Werner Micha , van Cauwenbergh Nora , Stigter Tibor , Alfonso Segura Leonardo , Betancur Vargas Teresita , Galvis Alberto , Avila Humberto
Published: March 2020

Despite a significant increase in attention for uptake of scientific results, the integration of emerging science in policy development and implementation remains challenging. The persistent gap between science and policy may frustrate the parties involved. For the scientists, the intended impacts of what are typically very much applied research efforts remain unattained. Those involved in policy implementation and development may perceive a lack of scientific support. This may particularly be the case in transitional countries, where the development of science may struggle to keep up with rapid societal and policy development; with several factors either impeding or facilitating the uptake of emergent scientific knowledge.

We implemented a series of participatory and action research activities to support the development and implementation of groundwater management policies in Colombia and explore barriers and enabling conditions to a functional science-policy interface. The factors that either impede or facilitate the process are examined through three case studies in different regions of the country. Although the national policies that govern groundwater resources management in these three areas are the same; the degree to which scientific knowledge is used to support policy implementation varies. Several factors are identified that influence the effectivity of the linkage, including among others; the availability of scientific knowledge; the establishing of trust relationships and positioning of institutions and stakeholders; as well as institutional readiness in supporting the policy implementation process. This comparison provides useful insight into how addressing some of the impeding factors may enrich the science-policy process.
Acquisition Protocol - Its Impact on Real-time Data Acquisition System Performance
Authors: Laporte Michael , Perlin Michael , Tatham Ben , Hosseini Mojtaba , Baturan Dario , Moores Andrew , Townsend Bruce
Published: March 2020

A fundamental element of real-time mission critical seismic monitoring networks is the data acquisition system, comprising the underlying protocol and the telemetry solution. Selection of the acquisition protocol can have significant impact on the outcomes sought by the seismic network such as data availability and usability as well as operational cost and even station and data center design.

We examine the performance of various acquisition protocols using a set of standard measures of system performance. Primary measures include bandwidth utilization, data latency and robustness (data completeness). In addition, protocol functionality and features, including support for multiple data types and state-of-health, are assessed for system impact on options for station, telemetry, and data center design as well as the overall functionality of the system solution.

Real-world and system generated data are employed and key quantitative measures of system effectiveness are identified and used as the basis of the analysis. Results of the analysis show the real-world impact of low level aspects like protocol selection on system performance.
Can point cloud data be used to calculate time to failure of a landslide?
Authors: Take Andy , Berg Nancy , Hori Toshikazu
Published: March 2020

Point cloud data capturing ground surface elevation at two instants in time are commonly used to identify the occurrence of landslides, identify their spatial extent, and to provide an estimate of the volume of depletion/accretion. In this study, it is hypothesized that this same point cloud data has the potential to yield much more valuable quantitative information regarding landslide behaviour, including the direction, magnitude, and rate of surface displacement.  Given point cloud data contains roughness information, shaded projections (hillshade images) of the slope at two or more instants in time can be processed using digital image correlation (DIC) to track displacement in the plane of the projection. If multiple view angles are used to generate the hill shade images, 3D surface displacements of the landslide surface should theoretically be resolved. Furthermore, if point clouds are generated with sufficiently high temporal resolution, it should be possible to estimate the time to failure. We explore this hypothesis in field experiment conducted in Tsukuba, Japan in which we bring a 3.5 m high earth dam to shear failure under high reservoir levels and extreme rainfall. Point clouds of the downstream dam surface generated at high temporal resolution were successfully used to calculate the 3D displacement of the dam surface, and to calculate the time of failure using the inverse-velocity method to within four minutes of the observed slope failure.
Putting the geo back into Biogeosciences
Authors: Schrodt Franziska
Published: March 2020

We increasingly recognize the diversity of biological systems, in terms of taxonomy, phylogeny and function, as well as the importance of biotic interactions in shaping them. However, the diversity of abiotic factors and interactions between biotic and abiotic diversity are still understudied, despite of Alexander from Humboldt’s advocacy over 200 years ago (Schrodt et al. 2019a). As such, we have lost sight of one of fundamental concepts of Biogeosciences: holistic integrative studies of patterns and processes across the Earth’s spheres.

In the face of accelerated anthropogenic and natural change of biotic and abiotic aspects, appreciation of the interaction diversity between all spheres of the Earth is urgently needed. Yet, to date, the vast majority of studies only account for the effect of climate and, potentially, soils on biodiversity, ignoring interactions (e.g. the effect of biodiversity on soils) and other aspects of geodiversity (the range, value and dynamics of geological, geomorphological, pedological and hydrological aspects and features of the Earth’s surface and subsurface). This applies to both, primary science and the science-policy interface.

I will give a brief introduction on the state-of-the-art in geodiversity – biodiversity interaction research, discuss the importance of incorporating the diversity of abiotic factors in biodiversity and conservation studies and indicate promising avenues for further research. This includes theoretical advancements, such as the recently introduced Essential Geodiversity Variables framework (Schrodt et al. 2019b), as well as practical matters, including remote sensing (Lausch et al. 2019) and modelling approaches suitable for expanding the geo- biodiversity interaction approach across the relevant spatial and temporal scales.

 

F Schrodt et al. (2019a) Challenges and opportunities for biogeography—What can we still learn from von Humboldt? Journal of Biogeography

 

F Schrodt et al. (2019b) To advance sustainable stewardship, we must document not only biodiversity but geodiversity. PNAS 116 (33): 16155 – 16158

 

A Lausch et al. (2019) Linking remote sensing and geodiversity and their traits relevant to biodiversity—part I: soil characteristics. Remote sensing 11 (20): 2356-2407
Bridging Long- and Short-term Behavior Shows Fault Strength as a Strain-average
Authors: van Dinther Ylona
Published: March 2020

The strength of faults is subject of an important debate throughout various Earth Scientific disciplines. Different scientific communities have different perspectives with respect to appropriate values for friction coefficients μ. Geodynamicists with a long-term perspective require very low effective strengths (μ<0.05), while at the same time realizing mountains need to be sustained as well. Geologists and seismologists typically start from Byerlee friction coefficients of 0.6<μ<0.85, whereas rock mechanics experiments at high seismic slip rates show short-term low dynamic friction values of 0.03<μ<0.3. Here I show that both long- and short-term approaches can be made more compatible through considering that a regional or global frictional strength should be approached as a strain-averaged quantity. Doing this accounts for large variations of strain in both time and space. What matters for large-scale models is that most deformation occurs over a very small space and time during which friction is exceptionally low, thus making the representative long-term strength low. This is supported by seismo-thermo-mechanical models that self-consistently simulate the dynamics of both long-term subduction and short-term seismogenesis. The latter sustain mountain building, while representative earthquake-like events occur on faults with pore fluid pressure-effective static friction coefficients between 0.125 and 0.005 (or 0.75<Pf/Ps<0.99). These low friction values suggest faults are weak and suggest the dominant role of fluid pressures in weakening faults in subduction zones. This is confirmed in analytical considerations based on mechanical energy dissipation, which provide an equation to calculate the long-term fault strength as a strain-average quantity. Constraining the four parameters in this equation by observations confirms that fluid weakening is more important for long-term weakening than dynamic frictional weakening and low static friction coefficients. From the short-term perspective of modeling earthquake rupture dynamics it is now also becoming evident that fluid overpressured faults are preferable. They namely facilitate the incorporation of laboratory-observed dynamic weakening (70-90%) by limiting the stress drop to reasonable values. In summary, this cross-scale perspective supports long-term effective friction values in the range of about 0.03 to 0.2.
Development of a drought monitor for South-Asia
Authors: Saha Toma Rani , Samaniego Luis , Shrestha Pallav K , Thober Stephan , Rakovec Oldrich
Published: March 2020

South Asia (SA) is highly vulnerable to extreme climatic events and experiences a wide range of natural hazards such as floods, drought, storms, and sea-level rise.  Droughts are recurrent in SA and its impact on regional agriculture, food storage, and livelihood is enormous. Agricultural droughts have severe consequences on the economy, society, health and water resources sectors. In this work, a state-of-the-art monitoring system of soil moisture drought in SA is developed. This study aims at improving the agricultural drought monitoring system for SA and contributing towards better adaptation solutions in the region. The SA drought monitoring system is inspired by the German Drought Monitor (www.ufz.de/duerremonitor)[1]. First, we implement the mesoscale hydrologic model (mHM, https://git.ufz.de/mhm) to reconstruct daily soil moisture from 1981 to 2019 using a near-real-time precipitation product (CHIRPS version 2, 0.25-degree resolution). Second, the SMI is estimated with a non-parametric kernel-based cumulative distribution function [2] based on mHM’s historic soil moisture reconstruction. The generated SMI maps are classified into five classes based on severity: abnormally dry, moderate drought, severe drought, extreme drought and exceptional drought. Third, we develop the South Asia Drought Monitor (SADM) which is an interactive web-portal (http://southasiadroughtmonitor.pythonanywhere.com/) for the dissemination of the simulated near-real-time drought classes. To achieve maximum dissemination, the daily and monthly SMI fields will be uploaded and published on the SADM portal. The SADM will help to inform decision-makers, the general public, researchers, and stakeholders in the SA. The drought monitoring system will allow the scientific community to conduct micro-level in-depth research and to enable policymakers to formulate proper planning and to take mitigation measures in sectors encompassing energy, health, forestry, and agriculture at local to regional scales.

 

[1] Zink, M., Samaniego, L., Kumar, R., Thober, S., Mai, J., Schäfer, D., Marx, A., 2016: The German drought monitor, Environ. Res. Lett. 11 (7), art. 074002, DOI:10.1088/1748-9326/11/7/074002.

[2] Samaniego, L., Kumar, R. and Zink, M.,2013: Implications of Parameter Uncertainty on Soil Moisture Drought Analysis in Germany, Journal of Hydrometeorology, DOI: 10.1175/JHM-D-12-075.1.

 
Corotating drift resonant electrons in Saturn's radiation belt: theory and observational evidence
Authors: Hao Yixin , Sun Yixin , Roussos Elias , Liu Ying , Yuan Chongjing , Krupp Norbert , Zong Qiugang
Published: March 2020

Corotating drift resonant (CDR) electrons, of which the gradient and curvature drift could cancel the corotation around the Saturn, could get efficiently radial transported when exposed to the Saturnian global convective electric field. Such fast radial transport could lead to significant adiabatic acceleration and therefore supply for the electron radiation belt population. In this work, the nonlinear trapping nature of the corotating drift resonance is investigated. Electrons trapped inside the resonant island preform a banana-like orbit in the equatorial plane. We present an estimation of the trapping limit in L shell and energy for the resonant electrons with varying first adiabatic invariant, which could be directly compared to CASSINI observations. The estimation of the trapping period also indicates that trapped electrons takes times of more hours to close their orbit than the traveling electrons. The evolution in energy spectrogram driven by Saturn's convection and corotation has also been predicted by our test particle simulations. We suggest  that the bifurcation of the 'zebra stripes' near the corotation drift resonant energy could be a diagnostic feature of the nonlinear CDR. Observations from MIMI/LEMMS with similar zebra stripes and the bifurcation have been found as predicted, proving that the electrons in Saturn's radiation belt are being transported radially by the convection and that corotating drift resonant could be a significant candidate for the plenishing of the Saturn's electron radiation belt.   
Spectral X-ray tomography for 3D mineral analysis
Authors: Sittner Jonathan , Godinho Jose R. A. , Renno Axel D. , Cnudde Veerle , Boone Marijn , De Schryver Thomas , Roine Antti , Liipo Jussi
Published: March 2020

Image based analytical tools in geoscience are indispensable for the characterization of minerals but most of them are 2D techniques, limited to the surface of a polished plane in a sample. X-ray micro computed tomography (micro-CT) is becoming a common analysis technique in geoscience and provides direct 3D information of the internal structure of a sample. A major drawback of micro-CT in the characterization of minerals, however, is the lack of chemical information. There have been different approaches to obtain chemical data using micro-CT but most of them are time consuming and difficult to adapt to regular use.

Therefore we introduce a potential new analytical tool: Laboratory-based Spectral X-ray Micro Computed Tomography (Sp-CT). Results from a spectral imaging detector prototype, installed inside a TESCAN CoreTOM micro-CT scanner, will be shown. This new analytical technique enables to obtain both high resolution structural and chemical information in 3D. With this information, the mineral distribution inside unbroken rocks and particles can be identified and quantified.

Based on the transmitted energy spectrum of a sample, main elements can be distinguished and minerals classified. It is also possible to quantify heavy elements within particles of complex composition and the measured sample volume is significantly larger compared to conventional analytical 2D techniques. Furthermore, Sp-CT is non-destructive and does not require sample preparation.

Sp-CT will open exciting new possibilities for mineral analysis. With this new technique, the 3D properties of the particles can now be measured and used for example in process mineralogy simulations. This is a major improvement to current simulations that predominantly use less representative 2D or bulk particle properties. Moreover, the Sp-CT could potentially be used as an alternative technique for regular characterization of ore deposits and processed ores since more representative volumes can be analyzed in a fast manner relative to existing techniques.

This research is part of the upscaling project “Resource Characterization: from 2D to 3D microscopy” and has received funding from European Institute of Innovation and Technology (EIT), a body of the European Union, under the Horizon 2020, the EU Framework Programme for Research and Innovation.
Challenges in implementing energy geo-structures in developing markets: Evidence from Romania
Authors: Prodan Iulia , Ban Horia , Bujor Octavian
Published: March 2020

Following the Directive 2010/31/EU on energy performance of buildings, EU state members have developed national plans for increasing the number of nearly zero energy buildings through measures that facilitate the implementation of renewable energy technologies. Due to this policies changes and also due to their incontestable advantages, energy geostructures are showing an increasing trend in number of implementations all across Europe. However, it is important that besides “good statistics”, the quality and efficiency of what is implemented to be ensured so that a real change is generated in terms of renewable energy exploitation and CO2 emissions reduction. The paper refers to challenges that are encountered in the process of implementation of energy geostructures especially on emerging markets for this technology, such as Eastern Europe, with emphasis on several case studies and evidence from Romania.
Analyzing social media photo posts distribution as a potential indicator for UGBI user preferences: the case of Coimbra, Portugal
Authors: Pinto Luis , Ferreira Carla , Pereira Paulo , Ferreira António
Published: March 2020

The Ecosystem Services provided by Urban Green and Blue Infrastructures (UGBI) are considered fundamental to improve the resilience of urban areas against the growing challenges of global warming. Indicators regarding the relevance and efficiency of UGBI are abundant, but they have been mainly focused on environmental related aspects, while the socio-cultural aspects of UGBI are still under represented. Considering the socio-cultural and recreational aspects, studies show that UGBI can significantly contribute for quality of life, sense of place, social interactions, physical wellbeing, learning, and other intangibles. A major and growing portion of recreation is indeed “nature-based", involving interactions with the natural environment. 
For these types of activities, different characteristics of the environment influence people’s decisions about where, when, and how to recreate. But fine-scale data collection regarding these aspects are usually site specific, and time and labour intensive. Wood et al. (2013) showed that the number of users who visit a location annually is related to the number of photographs taken in the same area and uploaded to the flickr database. 
Using the InVEST recreation model, this work aims to (1) test social media photo posts on Flickr as an indicator for the use of UGBI, and to (2) analyze its potential correlation with a set of cultural and recreational equipment in and around UGBI units. 
Two different periods are analyzed, with the intention to identify and evaluate the differences introduced with the implementation of a major city park near the river Mondego. 
The results show that the presence of the river and the proximity to the city center - with its old town - are major factors in the recreational use of the UGBI. They also show that the implementation of new UGBI units - under the form of a city park - can change the usage pattern of an area.
A customizable wide field-of-view multiband imager for lunar atmospheric Studies
Authors: Chakrabarti Supriya , Mukherjee Sunip , Cook Timothy , Baumgardner Jeffrey
Published: March 2020

Ground based observations have indicated that at times the lunar Sodium atmosphere extends beyond the Earth. However, to date no experiment has been conducted to perform an extended duration, in-situ observation of the lunar atmosphere.  We have designed a small (10 × 10 × 10 cm3 and a mass of 1.3 Kg), multi-band imager that operates in the CCD-band (approximately, 450 – 900 nm). The instrument is easily tailored to meet a specific application by selecting the appropriate combination of interference filters. If such an instrument is placed on a lunar orbiting platform, it will generate a long-term database to study the morphology of the lunar atmosphere or surface features observable in this band.

The instrument has an angular resolution of 0.1◦and a field of view of 35◦× 25◦. This large field of view is shared by a mosaic of interference filters chosen for a specific application. The instrument uses a custom-designed computer program for automatic exposure control and communicates using standard serial and ethernet protocols.

This design has been validated using commercial off-the-shelf components for sodium and potassium resonance emissions at 589 nm and 770 nm, respectively.
Integrating energy sectors in a state-resolved energy system model for Australia
Authors: Aboumahboub Tina , Brecha Robert , Gidden Matthew , Geiges Andreas , Bir Shrestha Himalaya
Published: March 2020

Australia represents an interesting case for energy system transformation modeling.  Wile it currently has a power system dominated by fossil fuels, and specifically with a heavy coal component, there is also vast potential for expansion and use of renewable energy.  Geographically, the country is divided into seven states and territories, two of which have power systems isolated from the rest of the country. Regions have widely differing characteristic energy mixes and resources, ranging from high reliance on brown coal (Victoria), black coal (New South Wales, Queensland), natural gas (Northern Territory, Western Australia) to states that have already moved toward renewable energy-dominant systems (South Australia, Tasmania). Renewable power systems across Australia are experiencing rapid growth, particularly in solar photovoltaics and to a lesser extent with wind power and battery storage. 

In order to better understand the further potential expansion of renewable power systems in Australia, we developed the Australian Energy Modelling System (AUSeMOSYS) based on the open-source OSeMOSYS framework. We apply AUSeMOSYS to investigate cost-optimal transformation pathways towards a carbon-neutral energy system. The model is calibrated carefully to recent past trends in energy generation, including the recent and near-future rapid uptake of renewables in different regions, whether by policy decision or autonomous development.  Beyond the power sector, AUSeMOSYS also provides scenario pathways for the uptake of electric vehicles and hydrogen powered transport, coupled to the power sector with a timeline through 2050. In order to investigate the full extent of renewable energy expansion given Australia’s recognized large renewable energy resource potential, we link selected industrial sectors to the power system model, e.g. steel production, where use of electric generation can further decarbonize Australia’s economy via hydrogen production and use.

In addition to the results showing the potential for large, integrated, cross-sectoral penetration of renewable energy into the Australian energy mix, we investigate modeling sensitivities to key parameters that can affect the uptake and use of renewable energy in the power system. For example, we study sensitivities in the choice of time-step resolution, the availability of trade between states in the National Energy Market (NEM) and the choice of carbon price and carbon cap pathways that can lead to near-zero emissions from the energy system by mid-century.
Validation of the SAMOA Operational Forecasting System in Spanish Mediterranean Ports
Authors: Liste Muñoz María , Mestres Ridge Marc , Espino Infantes Manuel , Grifoll Colls Manel , Sanchez-Arcilla Agustín , García León Manuel , García Sotillo Marcos , Álvarez Fanjul Enrique
Published: March 2020

Working in the coastal marine environment is highly challenging, among other reasons, due to the variety of extreme, seasonal, short and long-term environmental conditions that affect the coastline, beaches, infrastructures and port operations. The maritime climate directly affects the construction and maintenance of port infrastructures, the access of ships to ports, the safety of cargo handling operations, emergency response or the environmental management of effects of port operations. Currently, the ability to predict the sea state from a few hours to days has reached levels of precision and reliability unbelievable a few years ago. And all this, in combination with numerical measurements and predictions, has enabled significant advances in knowledge about meteorological and oceanographic conditions, making possible the development of forecasting systems to provide real, accurate and safe support in decision making in ports.

SAMOA initiative (System of Meteorological and Oceanographic Support for Port Authorities), developed by Spanish Port System (Puertos del Estado), in cooperation with Spanish Port Authorities, provides high-resolution coastal operational prediction systems in domains such as harbours and nearby coastal waters.

We present a high-resolution coastal operational prediction system which simulates the hydrodynamic in the Spanish Mediterranean Ports from April to September 2019. Bathymetry was built using a combination of bathymetric data from GEBCO (General Bathymetric Chart of the Oceans), and specific local high-resolution sources provided by port authorities. Daily updated hourly winds and heat and water fluxes from the Spanish Meteorological Agency forecast services were used as a surface forcing. The Regional Ocean Modelling System, ROMS, was used to investigate the hydrodynamics.

Three-day forecast of three-dimensional currents and other oceanographic variables, such as temperature, salinity, and sea level, were produced. These results were compared with field campaigns data, displaying agreements between model outputs and in-situ observations. Finally, a look ahead to the future of the operational prediction systems is provided as a useful tool to make informed decisions around port safety and efficiency.

We would like to acknowledge financial support from ECOSISTEMA-BC Project (CTM2017-84275-R), funded by the Spanish State Research Agency.
Insights from ultramafic nodules on the plumbing system of the Fogo Island 2014-2015 Eruption (Cape Verde)
Authors: Caldeira Rita , Mata João , Martins Sofia , Madeira José , Ramalho Rui , Silva Pedro , Moreira Mário
Published: March 2020

The last eruption on Fogo Island (Cape Verde Archipelago) occurred in 2014-2015, with mostly hawaiian and strombolian but sometimes vulcanian activity, with variable emission rates of lava flows, pyroclasts and gases (SO2 and CO2).   Some lava flows, mainly from the first stage of the eruption enclosed small granular ultramafic nodules (1-3cm), with angular to rounded shapes. The host rocks are porphyritic tephrites, with Ti-augite and Ti-magnetite phenocrysts and, sometimes, amphibole xenocrysts in a brown glassy matrix including laths of plagioclase, clinopyroxene and Ti-mgnetite.

The nodules are composed of an early crystallization phase olivine, in subheuedral crystals devoid of kink-bands or in rounded crystals enclosed in clinopyroxene oikocrysts. Clinopyroxene occurs in subeuhedral to anhedral zoned crystals, sometimes partially patchy replaced by late igneous amphibole which also occurs as primary crystals as well as in some xenocrysts. In both cases they frequently show reaction rims with transformation in rhonite, most probably resulting from degassing. Oxide minerals are present as a minor component occurring in sub-euhedral to anhedral crystals as inclusions in olivine and clinopyroxene or interstitially between silicate minerals.

The typical cumulus textures, and the mineral chemistry already obtained for the ultramafic nodules from the 2014 eruption at Fogo strongly suggest that they have a cumulate origin and are cognate with the host magmas. Indeed, the similar composition of Ti- augites from the nodules and phenocrysts (Wo49-51 En42-36 Fs12-10), as well as the olivine Fo contents and high CaO contents in olivine are explained by crystal segregation from the same magma of the host rock.

Geothermobarometric calculations point to crystallization temperatures for the cumulates between 1150 and 1200 ºC and pressures around 7- 10 kbar, while phenocrysts in host rocks crystallized at around 1000 ºC, and pressures of 3-4. These data confirm the existence of a polybaric plumbing system feeding the 2014-15 Fogo eruption, with some of the reservoirs having developed at mantle depths (at least 22 km).   

 

This research received financial support from FCT (Fundação para a Ciência e Tecnologia) through project FIRE (PTDC/GEO-GEO/1123/2014).
Methane emission from dairy farm located in north of Heidelberg
Authors: Korben Piotr , Kammerer Johannes , Wietzel Julia , Schmidt Martina
Published: March 2020

The three major anthropogenic CH4 (methane) sources in Germany are ruminants (53%), waste and waste water treatment (22%) and transport and storage of natural gas (25%). In order to quantify these emissions on a facility scale, we used a CH4 analyser installed in vehicle. Mobile measurements are performed on regular campaigns including measurements of the concentration and isotopic composition of methane. During this study we visited  11 times a Dairy Farm in Weinheim, north of Heidelberg. The farm has a livestock of about 320 - 340 dairy cows with an average milk production of 29 l per cow and day. A biogas plant is located next to the cowshed. To determine the temporal and spatial variability of emissions, collected data are analysed with Gaussian plume model to obtain emissions from dairy cows and biogas plant. For each mobile measurements campaign, we analysed 10 -40  transects (driving the car forward and backward). The first estimations of the emissions  (cows and biogas included) shows strong variabilities and up to 8 times higher values, than expected when comparing to IPCC reported emission values for dairy cows . As our measurements represent the whole farm emission, including  biogas plant and liquid manure, we have to distinguish these sources and quantify the contribution of each. .