bluuebunny/crossref_metadata_2025 huggingface dataset:
The Diurnal Cycle of Precipitation: A Comparison of State-of-the-Art Observations and Models
Authors: Watters Daniel , Battaglia Alessandro , Allan Richard
Published: March 2020

Representation of the diurnal cycle is a key trial of the ability of models to capture precipitation timing, duration, and intra-daily variations.  The state-of-the-art model simulations from the Coupled Model Intercomparison Project (CMIP6), which are set to inform the upcoming IPCC sixth assessment report, are yet to be compared to the diurnal cycle of precipitation according to observations.  The recently released version 6 of the Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG) product provides over 19 years of global-gridded observations (June 2000 - Present).  Such state-of-the-art observations, with inputs from space-borne dual-frequency radar, microwave radiometers, infrared sensors and ground-based gauges, have never been available at 0.1˚ gridding every half hour over such a long period.  This study aims to compare the amplitude and time of maximum precipitation accumulation between IMERG observations and CMIP6 models over an 8-year period (June 2000 – May 2008).  Preliminary results suggest that the CMIP6 models typically underestimate the amplitude of precipitation accumulation over land compared to observations, though there are overestimates in the Amazon and across central Africa.  Furthermore, the CMIP6 models typically lag behind observations in their time of maximum accumulation over land; observations suggest a late evening to night maximum whilst CMIP6 models show a late morning to early afternoon maximum.  The results will be beneficial to improving modelling of precipitation across the globe.
The benefits of performing continuous gravity measurements at active volcanoes using superconducting gravimeters
Authors: Greco Filippo , Carbone Daniele , Cannavò Flavio , Messina Alfio , Contrafatto Danilo , Siligato Giuseppe , Reineman Richard , Warburton Richard
Published: March 2020

Continuous gravity measurements at active volcanoes are mostly accomplished using spring gravimeters, that can be operated under harsh field conditions. Unfortunately, these instruments do not provide reliable continuous measurements over long time-scales, due to the instrumental drift and artifacts driven by ambient parameters.

An alternative to spring devices for continuous measurements is given by superconducting gravimeters (SGs), that are free from instrumental effects and thus allow to track even small gravity changes over time-scales from minutes to years. Nevertheless, SGs cannot be deployed in close proximity to the active structures of tall volcanoes, since they need host facilities with main electricity and a large installation surface.

The mini-array of three SGs that were installed on Etna between 2014 and 2016 makes the first network of SGs ever installed on an active volcano. Here we present results from these instruments and show that, even though they are installed at relatively unfavorable positions (in terms of distances from the summit active craters), SGs can detect volcano-related gravity changes that would otherwise remain hidden, thus providing unique insight into the bulk processes driving volcanic activity.
Modeling Surficial Water runoff and estimation of its damaging factor on Rock Curved Cultural Heritage Monuments of Georgia – Application of Close Range Aerial Photogrammetry
Authors: Nadaria Akaki , Kirkitadze Giorgi , Lobjanidze Mikheil , Vacheishvili Nikoloz , Elashvili Mikheil
Published: March 2020

Rock curved monuments of Georgia, represent a unique cultural heritage – an ancient cities, churches and kelly carved in rock, painted and decorated by hermit monks, which unites architectural monument and Natural-Geological complex. Such monuments are particularly vulnerable and their restoration and conservation requires a complex approach. These monuments, as many other similar monuments worldwide, is subjected to slow but permanent process of destruction, expressed in several main factors, one of which is rock weathering caused by surface rainwater runoff and water infiltration, coupled with temperature variations.

Close Range Aerial Photogrammetry, with its actively developing applications has been used to address this problem. Several Rock Curved Monuments of Georgia: Vardzia (12th Century), Vanis Qvabebi (8th Century) and Uplistsikhe (Late bronze period) were studied. First two of which represent large Monastery complexes curved in Volcanic tuff and tuff-breccia, while the Uplistsikhe represents ancient Rock Curved town, constructed in a coarse-grained week sandstone, with roots deep in the history of Georgian state.

To achieve sustainable preservation of cultural heritage rock-curved monuments, this particular type of danger should be addressed: Preservation of structural integrity of monument and avoiding ground or surficial water infiltration is substantial to preserve unique mural paintings and wall inscriptions, still preserved in these Rock Curved Monuments.

High-resolution Digital Elevation Models and Orthographic Aerial Photo images (in vertical and horizontal perspectives) were constructed through several aerial missions. Spatial data was accurately Georeferenced using the DGPS RTK system and Total Station (for vertical cliffs).  The obtained data serves as an input for the Hydromodeling of Surficial water runoff, calculated using the ArcMap Hydro tool extension. Moreover, high-resolution photo textures allowed to estimate the damaging effect of formed water channels and crack systems of water infiltration. Conceptual solutions of water drainage systems allowing surficial water diversion and mitigation of its effect on rock strata were elaborated and even constructed in the case of Vardzia. Aerial Photogrammetry as a tool for routine periodic inspection has been adopted for the given monuments, where the damaged areas are hardly accessible by foot and even highly dangerous for the access of rock climbers.
Remote Sensing for Monitoring and Mapping Karst Groundwater Flooding in the Republic of Ireland
Authors: Campanyà i Llovet Joan , McCormack Ted , Naughton Owen
Published: March 2020

Karst related groundwater flooding represents a significant hazard in many rural communities in Ireland. A series of unprecedented flood events in recent years have reinforced the need to improve our ability to quantify the location and likelihood of flood occurrence. Geological Survey Ireland, in collaboration with Carlow Institute of Technology and Trinity College Dublin, has established a collaborative project to investigate groundwater flooding, with particular emphasis on seasonal karst lakes known as turloughs. There are over 400 recorded turloughs across Ireland, the majority of which located on limestone lowlands. Turloughs can completely dry during summer months but extend to hundreds of hectares during the winter flood season. The practical limitations of establishing and maintaining a network of over 400 turloughs supported the use of remote sensing and GIS techniques to delineate flood extents and monitor flood prone areas using satellite imagery such as of the ESA Copernicus programme. Measurements at 50 sites for over 18 months were used to calibrate and validate results from satellite data. With limited recorded groundwater flood data in Ireland, the use of remote sensing data provides historical archives of images to look at past flood conditions to optimise the detection of groundwater and delineate maximum groundwater flood maps. These new data improve the fundamental hydrological understanding of groundwater flooding in Ireland, enabling key stakeholders to develop appropriate flood mitigation measures and allow for informed flood assessments to be made in future. Additionally, it is a first step towards implementation of near-real time monitoring and forecasting of groundwater levels, and the evaluation of the impact of climate change to groundwater systems in Ireland.
Passive Reflection Seismic Imaging of the North Anatolian Fault at crustal-scale: A Matrix Framework for Aberrations Correction
Authors: Touma Rita , Campillo Michel , Aubry Alexandre , Blondel Thibaud
Published: March 2020

To understand fault systems, it is required to identify the structure of the crust and upper mantle. Seismic investigations have long been relying on active sources generating an incident wave-field from the Earth surface. The reflected wave-field is then recorded by sensors deployed at the surface. Nowadays, passive imaging has been adopted as an alternative of this source-receiver configuration by computing the correlations of ambient noise. This process allows to estimate the Green’s function between two receivers. We here present a passive imaging technique applied to data recorded with the Dense Array of North Anatolia [1], which was deployed in western Turkey during 16 months. The array consists of 73 stations covering the two major fault branches of the North Anatolian Fault (NAF). Inspired by previous works in optics and acoustics, we introduce a matrix approach of seismic imaging based on seismic noise cross correlations. Our method applies focusing operations at emission and reception (Blondel et al.,2019) allowing to project the reflection matrix recorded at the surface to depth (redatuming). Although seismic noise is dominated by surface waves, focusing operations allow to extract the body wave components that carry information about the reflectivity of in-depth structures. However, complex velocity distribution of the Earth’s crust results in phase distortions, referred to as aberrations in the imaging process. Phase distortions prevent the imaging of the true reflectivity of the subsurface leading to unphysical features and blurry images. To overcome these issues, we introduce a new operator: the so-called distortion matrix. It connects any virtual source induced by focusing at emission with the distorted part of the reflected wave-front in the spatial Fourier domain. A time-reversal analysis of the distortion matrix allows to correct for high-order aberrations. Crustal-scale 3D images of the fault structure of the North Anatolian Fault are revealed with optimal resolution and contrast.

(1) DANA. Dense array for north anatolia. International Federation of Digital Seismograph Networks doi:10.7914/SN/YH2012, 2012.
Coastal circulation from along-track satellite altimetry along the northern inner shelf of the Gulf of Cadiz
Authors: Garel Erwan , Júnior Luciano , Relvas Paulo , Laiz Irene , Gómez-Enri Jesús
Published: March 2020

Satellite-derived sea level records are generally known to be unreliable in coastal zones. However, major progresses have been made during the last decade based on improved corrections and reprocessing of along-track altimeter data. In this study, altimeter-derived CryoSat-2 products are used to study the coastal circulation along the inner northern shelf of the Gulf of Cadiz, at the southern extremity of the western Iberian upwelling system. Coastal upwelling in this region results from coastal divergence due offshore Ekman transport under westerly favourable wind, and gives theoretically origin to a cross-shore pressure gradient. Upwelling activity is usually identified based on sea temperature cooling at the coast and the development of upwelling jets produced by geostrophic balance. These eastward alongshore flows alternate with westward flows (Coastal Counter Currents, CCCs) which main driver (e.g., local wind stress, geostrophic balance or alongshore pressure variations) is not definitively identified yet.

The present research proposes to get insights into the factors that drive the coastal circulation, based on the Absolute Dynamic Topography (ADT) obtained from CryoSat-2 along-track products (in SAR mode). The studied coastal stretch, about 200 km in length, is broadly oriented E-W, allowing the use of (the meridional) satellite tracks for the determination of cross-shore sea level variations. For validation, sea level oscillations from tidal gauges are compared with sea level anomalies from nearby tracks. In general, the satellite-derived sea level data reproduce adequately the temporal trends of water level variations at the coast. However, the CryoSat-2 data obtained at less than 3/5 km from the coast was discarded to reduce potential error in the magnitude of the variations.

The coastal circulation along the coast is diagnosed based on Sea Surface Temperature (SST) satellite images and in situ Acoustic Doppler Current Profilers (ADCP) observations on the inner shelf. Remarkably, the validated cross-shore sea level data show that the water level is systematically lower near the coast during periods of active coastal upwelling. The width of the sea level gradient varies between 10 and 25 km, and closely corresponds to the cold water area identified from SST images. The corresponding geostrophic flow is estimated about 0.5 m/s, similar to the observed upwelling jets near the surface. By contrast, periods with CCCs generally correspond to a flat cross-shore slope, discarding geostrophic balance as their main driver. On-going work analyses jointly CryoSat-2 tracks which are temporally closed for the determination of sea level and slope variations along the coast associated to the development of strong alongshore flows.
Uncertainty quantification and global sensitivity analysis with dependent inputs: Application to the 2D hydraulic model of the Loire River
Authors: Pheulpin Lucie , Bacchi Vito
Published: March 2020

Hydraulic models are increasingly used to assess the flooding hazard. However, all numerical models are affected by uncertainties, related to model parameters, which can be quantified through Uncertainty Quantification (UQ) and Global Sensitivity Analysis (GSA). In traditional methods of UQ and GSA, the input parameters of the numerical models are considered to be independent which is actually rarely the case. The objective of this work is to proceed with UQ and GSA methods considering dependent inputs and comparing different methodologies. At our knowledge, there is no such application in the field of 2D hydraulic modelling.

At first the uncertain parameters of the hydraulic model are classified in groups of dependent parameters. Within this aim, it is then necessary to define the copulas that better represent these groups. Finally UQ and GSA based on copulas are performed. The proposed methodology is applied to the large scale 2D hydraulic model of the Loire River. However, as the model computation is high time-consuming, we used a meta-model instead of the initial model. We compared the results coming from the traditional methods of UQ and GSA (i.e. without taking into account the dependencies between inputs) and the ones coming from the new methods based on copulas. The results show that the dependence between inputs should not always be neglected in UQ and GSA.
Low cost sensors and crowd-sourced data to map air pollution in urban areas
Authors: Carbajales Rodrigo , Iurcev Massimiliano , Diviacco Paolo
Published: March 2020

Low cost sensors and crowd-sourcing data could potentially revolutionise the way air pollution measurements are collected providing high density geolocated data. In fact, so far data have been collected mostly using dedicated fixed position monitoring stations. These latter rely on high quality instrumentation, well established practices and well trained personnel, which means that, due to its costs, this paradigm entails limitations in the resolution and extension of geographic sampling of an area.

The combination of low costs sensors and volunteer-based or opportunistic acquisition of data can, instead, possibly turn the cost issue into an advantage. This approach, however, introduces other limitations since low cost sensors provide less reliable data and crowd source acquisition are subjects to data gaps in space and time.

In order to overcome these issues redundant data from multiple platforms have to be made available. On one hand this allows statistics to be applied to identify and remove anomalous values, and on the other hand when multiple platforms are used, the chances to have a better coverage and more reliable data  increases.

To implement this approach OGS developed the full suite of tools that has been named COCAL that allow to follow the full path from the acquisition, transmission, storage, integration and real time visualization of the crowdsourced data.

Low cost sensors for the detection of suspended particulate matter size 2.5 and 10 µm, together with atmospheric pressure, humidity and temperature, have been combined with GPS positioning and transmission (being able to opt for GSM, WiFi or LoRaWAN transmission) unit in a black box that can be attached to any moving vehicle travelling in an area. This way large areas can be sampled with high geographic resolution.

Atmospheric data are collected in an InfluxDB database, which allows easy integration with TheThingsNetwork for LoRaWAN network management and directly with GSM and WiFi connections. Public users are provided with a real-time web interface based on OpenLayers for map visualization. Server based processing and conversion scripts generate both filtered data and aggregate data, by computing averages on a spatial and temporal grid.. Finally, automatic interpolation techniques like Inverse Distance Weighting or Natural Neighbours may provide detailed online maps with contouring and boundary definition. All products are available in near real-time through OGC compliant web services, suited for an easy integration with other repositories and services.
An integrated approach for understanding long-term volcano dynamics based on absolute gravity and GNSS measurements
Authors: Bonforte Alessandro , Greco Filippo , Carbone Daniele
Published: March 2020

Here we present the results of repeated Absolute Gravity and GNSS measurements, collected at Mt. Etna (Italy) between 2009 and 2018. We aim at investigating the capabilities of this integrated approach for understanding the dynamics of magmatic sources over time-scales of months to years. The absolute gravity and GNSS campaign measurements were repeated roughly once a year; in order to improve the time resolution of gravity data, in some stations we performed, besides absolute gravity measurements, also relative measurements at intervals shorter than 1 year.

After being corrected for the effect of elevation changes, gravity data reveal an increase/decrease cycle, well spatio-temporal correlated with a general pattern of uplift/subsidence, during a period of intense lava fountains from the summit craters.

Our results provide insight into the processes that controlled the transfer of the magma from deeper to shallower levels of the plumbing system of Mt. Etna volcano, in periods preceding/accompanying the eruptive activity during 2009–2018.

Specifically, we propose that coupled changes in height-corrected gravity and elevation might be induced either by the magma storage/withdrawal below the volcanic pile, or by fluids pressurization/depressurization, or by a combination of both processes.

The application of the proposed approach could led to an improved capability to identify processes heralding eruptions.
Recent microseismicity observed at Hekla volcano and first velocity inversion results
Authors: Möllhoff Martin , Rezaeifar Meysam , Bean Christopher J. , Vogfjörd Kristin S. , Bergsson Bergur H. , Buxel Heiko
Published: March 2020

Hekla is one of the most active and dangerous volcanoes in Iceland presenting a high hazard to air travel and a growing tourist population. Until now the pre-eruption warning time at Hekla is only around one hour.  In 2018 we installed the real-time seismic network HERSK directly on Hekla's edifice. If microseismicity on Hekla increases prior to the next eruption the network could possibly provide a means to improve early warning. In addition it is hoped that HERSK will better our understanding of the processes driving the evolution of pre-eruptive seismicity. The configuration and tuning of a dedicated real-time detection and location system requires the determination of a suitable velocity model and station corrections. We present a catalogue of recently detected local events that we use to invert for a 1-D velocity model. We observe significant variations in station corrections and conclude that it is important to account for these in the real-time detection and location system which we are developing based on the SeisComp3 software.
New Insight Into the Formation and Evolution of the East Reykjanes Ridge Current and Irminger Current
Authors: Thierry Virginie , Petit Tillys , Mercier Herlé
Published: March 2020

The Reykjanes Ridge strongly influences the circulation of the North Atlantic Subpolar Gyre as it flows to the Irminger Sea from the Iceland Basin. The circulation is composed of two main along‐ridge currents: the southwestward East Reykjanes Ridge Current (ERRC) in the Iceland Basin and the northeastward Irminger Current (IC) in the Irminger Sea. To study their interconnection through the ridge, as well as their connections with the interior of each basin, velocity and hydrological measurements were carried out along and perpendicular to the crest of the Reykjanes Ridge in June–July 2015 as part of the Reykjanes Ridge Experiment project. This new data set changes our view of the ERRC and IC as it reveals undocumented along‐stream evolutions of their hydrological properties, structures, and transports. These evolutions are due to flows connecting the ERRC and IC branches at specific locations set by the bathymetry of the ridge and to significant connections with the interiors of the basins. Overall, the ERRC transport increases by 3.2 Sv between 63°N and 59.5°N and remains almost constantly southward. In the Irminger Sea, the increase in IC transport of 13.7 Sv between 56°N and 59.5°N, and the evolution of its properties are explained by both cross‐ridge flows and inflows from the Irminger Sea. Further north, bathymetry steers the IC northwestward into the Irminger Sea. At 63°N, the IC water masses are mostly issued from the cross-ridge flow.
Predicting the impact of Giant Molerat influenced vegetation on Sanetti Plateau, Bale Mountains, Ethiopia
Authors: Wraase Luise , Reuber Victoria , Kurth Philipp , Farwig Nina , Miehe Georg , Opgenoorth Lars , Schabo Dana , Nauss Thomas
Published: March 2020

Ecosystem engineers continuously shape and re-shape the spatial and temporal structure of the environment. Burrowing animals are an important group of ecosystem engineers, because of their ability to rework sediments and soils with consequences for e.g. soil formation and vegetation patterns. Simultaneous, burrowing animals depend on climate, local soil characteristics and vegetation. The endemic Giant Molerat (GMR) is a burrowing animal and important ecosystem engineer in the Bale Mountains. As part of the Bale Mountain Exile Hypothesis Project, the aim of this study is to investigate (1) the interlinkages between GMR, climate and vegetation patterns as well as (2) to upscale the influence of GMR on the vegetation pattern across the plateau with Sentinel satellite data. Field data comprise 47 paired plots of 5m x 5m with and without GMR activity. Additionally, 1.500 independent GMR burrow openings have been mapped. For investigating interlinkages, all parameters are first pre-analysed for correlations and their dependencies (1). In the following these results, the remote sensing data and the individual variables are implemented into the prediction model. To increase the accuracy, an error correction of the model is pursued. For this, the area is calculated into likelihoods of areas influenced by GMR, based on the vegetation survey pairs serving as training areas for the correction. The corrected results are used as final input model in a machine learning-based classification approach using Random Forest with forward-feature selection and leave-feature-out option (2). In the following the results of this ongoing upscaling approach used for the Sanetti Plateau, Ethiopia is presented.
A statistical model of the global carbon budget
Authors: Bennedsen Mikkel , Hillebrand Eric , Koopman Siem Jan
Published: March 2020

We propose a statistical model of the global carbon budget as represented in the annual data set made available by the Global Carbon Project (Friedlingsstein et al., 2019, Earth System Science Data 11, 1783-1838). The model connects four main objects of interest: atmospheric CO2 concentrations, anthropogenic CO2 emissions, the absorption of CO2 by the terrestrial biosphere (land sink) and by the ocean (ocean sink).  The model captures the global carbon budget equation, which states that emissions not absorbed by either land or ocean sinks must remain in the atmosphere and constitute a flow to the stock of atmospheric concentrations. Emissions depend on global economic activity as measured by World gross domestic product (GDP), and sink activity depends on the level of atmospheric concentrations (fertilization). The model is cast in a state-space system, which facilitates estimation of the parameters of the model using the Kalman filter and the method of maximum likelihood. We illustrate the usefulness of the model in two applications: (i) short-horizon forecasts of all variables in the model, which is an output of the Kalman filter; and (ii) long-horizon projections of climate variables, implied by certain assumptions on future World GDP, are constructed from the model and compared with those coming from the Representative Concentration Pathway scenarios. The statistical nature of the model allows or an assessment of parameter estimation uncertainty in the forecast and projection exercises.
A high capacity, automatic and small-volume water sampler
Authors: Martínez-Carreras Núria , Barnich François , Iffly Jean François , O'Nagy Oliver , Popleteev Andrei
Published: March 2020

Field deployable and portable automatic water samplers are common tools in hydrology. They allow the unattended collection of water samples at predetermined times or triggered by external sensors, reducing personnel labour and costs. Several automated water samplers have been described in the literature. However, the vast majority of these samplers are not commercialised and their use is very limited or restricted to research applications. We can broadly classify these samplers in three groups: in situ samplers, sequential precipitation samplers and siphon automatic samplers. The latest are commonly used by hydrologists, environmental monitoring agencies and in wastewater treatment plants. They were first patented and commercialized in the 1980s by Teledyne-ISCO (Lincoln, NE, USA). They use a peristaltic pump to transfer water into several containers. However, the siphon automatic samplers are large, heavy and typically collect a maximum of 24 samples of 0.5 or 1 L. Here, we present a new automatic water sampler that has a larger and variable storage capacity (from 64 to 400) of smaller containers (from 2 to 40 mL). We argue that for many applications large sample volumes are no longer required due to the improvement of chemical analytic techniques. Standard laboratory storage boxes are filled with standard laboratory containers and directly placed inside the sampler, reducing the processing time once the samplers are back in the laboratory. Containers remain always closed with a septum cap to prevent evaporation. The sampler allows tub rinsing between sample collection to prevent contamination and memory effects. It is portable, has a low-power consumption and is robust for its use under field conditions. We tested the prototype in the laboratory and in the field. We will present the sampler mechanical functioning, the results of the tests (e.g. sample preservation and memory effects) and the user-friendly interface to define sampling schemes.
Structural relief across the NW segment of the Zagros Mountain Front Flexure in the Kurdistan Region of Iraq: implications for basement thrusting
Authors: Zebari Mjahid , Grützner Christoph , Balling Philipp , Ustaszewski Kamil
Published: March 2020

Within the NW segment of the Zagros belt in the Kurdistan Region of Iraq, the Zagros Mountain Front Flexure separates the High Folded Zone from the Foothill Zone and forms a pronounced topographic and structural step. Due to the lack of outcrops and subsurface data, balanced and kinematic valid geometrical interpretations for the subsurface deformation associated with this step are not well constrained yet. To solve this, we estimated the structural relief across seven regional transects crossing the Mountain Front Flexure and we constrained the geometry of deformation from deformed-state and forward-modeled balanced cross-sections. The calculated structural relief for six out of seven transects ranges from 2 to 3 km. By using forward modeling, we show that predominantly thick-skinned deformation is needed to explain this amount of relief across the Mountain Front Flexure. Our best-fitting result suggests c. 6.5 km of displacement along a basement thrust fault that dips c. 25° at the top of the basement and that is shallowing downwards. About 4.2 km of this displacement on the basement fault were accommodated up-section by thrust-related and detachment folding of the Triassic and younger units within two prominent anticlines. About 2.3 km of displacement was transferred to the Foothill Zone, forming detachment folds above the Triassic detachment level. Inclined river terraces on the flank of anticlines within the Foothill Zone indicate ongoing displacement on this basement fault. The amount of shortening within the low topographic part of the belt from the deformation front to the limit of seismogenic thrusting within the Imbricated Zone, implies that the Late Miocene to Quaternary shortening rates there were much lower than the present-day geodetically derived convergence rates for this part of belt. These results shed new light on the geometry of the Zagros and its structural evolution.
Assessing the impact of fluvial dynamics on floodplain soil contamination and microbiota in the transboundary Drava River Floodplain
Authors: Szabó Péter , Jordan Gyozo , Kocsis Tamás , Šajn Robert , Alijagić Jasminka
Published: March 2020

Floodplains have received significant attention recently because they are densely populated areas, covered by fertile agricultural lands and act as diverse riverine habitats. At the same time, these important areas are sensitive receptors of PTE (Potentially Toxic Elements) contamination originating from upstream mining and industrial areas endangering food safety and the ecosystems. The large Drava River catchment has been impacted by industrial activities since historic times. Previous studies have shown that the alluvial sediments record the contamination from upstream mines and smelters (e.g. Bleiberg-Kreuth in Austria, Cave del Predil in Italy and Mežica in Slovenia).

Floodplain topsoil (depth: 0-10cm) and subsoil (depth: 50-60cm) samples in the actively flooded alluvial plains and river terraces were collected along 10 cross-sections all along the Hungarian-Croatian border river Drava. In order to study the impact of contamination on soil microbiota, the samples were analysed with ICP-MS for chemical composition, FDA (Fluorescein Diacetate) tests were made for the bulk microbial activity assessment, β-glucosidase content was measured for the rate of catabolic activities, furthermore Docosahexaenoic acid (DHA) content for describing the anabolic processes, and phosphatase enzyme for assessing the mobility of phosphorus. Total cell number was counted on Tryptone Glucose Yeast Extract and the number of fungi on Rose Bengal Agar with Chloramphenicol.

Data was modelled with data analysis methods including descriptive statistics, regression models and homogeneity tests, complemented by spatial visualisation with GIS based softwares. Results show that there is a significant difference between alluvial plain and river terrace sediment contamination, while soil depth (topsoil vs subsoil) seems to be an important factor for soil microbiological parameters.

This research contributes to a Slovenian-Hungarian OTKA project (SNN OTKA 118101). The project was co-funded by European Union Fund, ERDF, IPA, ENI (DTP2-093-2.1 SIMONA).
Modelling understory light availability in a heterogeneous landscape using drone-derived structural parameters and a 3D radiative transfer model
Authors: Fawcett Dominic , Bennie Jonathan , Anderson Karen
Published: March 2020

The light environment within vegetated landscapes is a key driver of microclimate, creating varied habitats over small spatial extents and controls the distribution of understory plant species. Modelling spatial variations of light at these scales requires finely resolved (< 1 m) information on topography and canopy properties. We demonstrate an approach to modelling spatial distributions and temporal progression of understory photosynthetically active radiation (PAR) utilising a three dimensional radiative transfer model (discrete anisotropic radiative transfer model: DART) where the scene is parameterised by drone-based data.

The study site, located in west Cornwall, UK, includes a small mixed woodland as well as isolated free-standing trees. Data were acquired from March to August 2019. Vegetation height and distribution were derived from point clouds generated from drone image data using structure-from-motion (SfM) photogrammetry. These data were supplemented by multi-temporal multispectral imagery (Parrot Sequoia camera) which were used to generate an empirical model by relating a vegetation index to plant area index derived from hemispherical photography taken over the same time period. Simulations of the 3D radiative budget were performed for the PAR wavelength interval (400 – 700 nm) using DART.

Besides maps of instantaneous above and below canopy irradiance, we provide models of daily light integrals (DLI) which are assessed against field validation measurements with PAR quantum sensors. We find relatively good agreement for simulated PAR in the woodland. The impact of simplifying assumptions regarding leaf angular distributions and optical properties are discussed. Finally, further opportunities which fine-grained drone data can provide in a radiative transfer context are highlighted.
Reconciling reconstructions and simulations of the Greenland ice sheet and its climate during the Last Interglacial period
Authors: Robinson Alexander , Capron Emilie , Alvarez-Solas Jorge , Bender Michael , Goelzer Heiko , Montoya Marisa
Published: March 2020

There is still no consensus concerning the evolution of the Greenland ice sheet during the Last Interglacial period (LIG, 130-115 kyr ago). Ice cores indicate that the ice sheet survived over most of the continent. Proxy data indicate temperature anomalies of up to 6-8°C. However, under these conditions, models predict almost complete deglaciation. This paradox must be resolved to be able to quantify Greenland’s sea-level contribution during the LIG as well as to understand its sensitivity to future climate change. Here we analyze the available evidence and outline strategies to reconcile modeling and data efforts for Greenland during the LIG.
Sensors applied in the detection of physical changes at heritage buildings
Authors: Török Ákos , Antal Ákos
Published: March 2020

Heritage buildings are susceptible to environmental impacts, and many of the stone structures show intense damage due to weathering, soil instability or improper use. The detection of changes has primary importance in the understanding of deterioration processes, and it provides essential information for the preservation of these structures. The application of destructive techniques to assess the condition of the materials of these heritage structures are not feasible and in most cases, not permitted. Consequently, monitoring of the health of the construction material and the structure require techniques that are not destructive and automatically collects data from the sites. The study provides an overview of sensors that could be applied in monitoring of the conditions of cultural heritage structures. From the methods of placing sensors at sites to available data collection system – the entire process will be overviewed. Applications of spectroscopic sensors for in situ and real-time analysis of critical colorimetric parameters of building materials will be presented. Application of artificial intelligence-based data processing in the prediction of material degradation is also discussed. Optical detectors of remote sensing techniques applied in monitoring of heritage buildings are also addressed. The financial support of National Research, Development and Innovation (NKFI) Fund (K 116532) is appreciated.
Small-scale processes with large-scale impacts: Investigating canopy structure controls on energy fluxes to the forest snowpack
Authors: Mazzotti Giulia , Essery Richard , Malle Johanna , Webster Clare , Jonas Tobias
Published: March 2020

Forest canopies strongly affect snowpack energetics during wintertime. In discontinuous forest stands, spatio-temporal variations in radiative and turbulent fluxes create complex snow distribution and melt patterns, with further impacts on the hydrological regimes and on the land surface properties of seasonally snow-covered forested environments.

As increasingly detailed canopy structure datasets are becoming available, canopy-induced energy exchange processes can be explicitly represented in high-resolution snow models. We applied the modelling framework FSM2 to obtain spatially distributed simulations of the forest snowpack in subalpine and boreal forest stands at high spatial (2m) and temporal (10min) resolution. Modelled sub-canopy radiative and turbulent fluxes were compared to detailed meteorological data of incoming irradiances, air and snow surface temperatures. These were acquired with novel observational systems, including 1) a motorized cable car setup recording spatially and temporally resolved data along a transect and 2) a handheld setup designed to capture temporal snapshots of 2D spatial distributions across forest discontinuities.

The combination of high-resolution modelling and multi-dimensional datasets allowed us to assess model performance at the level of individual energy balance components, under various meteorological conditions and across canopy density gradients. We showed which canopy representation strategies within FSM2 best succeeded in reproducing snowpack energy transfer dynamics in discontinuous forests, and derived implications for implementing forest snow processes in coarser-resolution models.
Unravelling pre-eruptive P-T conditions by machine learning
Authors: Petrelli Maurizio , Caricchi Luca , Perugini Diego
Published: March 2020

Clinopyroxene based thermometers and barometers are widely used tools for estimating temperature and pressure conditions under which magmas are stored before eruptions.

Several studies reported the development and the application of Clinopyroxene–liquid geothermobarometers in many different volcanic environments, also warning on the potential pitfall in using overly complex models [e.g., 1 and references therein]. The main drawback in the use of models with a large number of parameters is the potential overfitting of the calibration data, yielding a poor accuracy in real-world applications. On the other hand, simpler models cannot account for the complexity of natural magmatic systems, requiring different calibrations for different magma chemistries [e.g., 2, 3].

In the present study, we report on the development of Clinopyroxene and Clinopyroxene-liquid thermometers and barometers in a wide range of P-T-X conditions using Machine Learning (ML) algorithms. To avoid overfitting and demonstrate the robustness of the different methods, we randomly split the dataset into training and validation portions and repeating this procedure up to 10000 times to trace the performance of each of the used algorithms. We compared the performance of ML algorithms with classical and established Clinopyroxene and Clinopyroxene-liquid thermometers and barometers using local and global calibrations. Finally, we applied the obtained thermometers and barometers to real study cases.

 

[1]      K. D. Putirka, Thermometers and barometers for volcanic systems, Minerals, Inclusions and Volcanic Processes, 69. 61–120, 2008.

[2]      D. A. Neave, K. D. Putirka, Am. Mineral., 2017, DOI:10.2138/am-2017-5968.

[3]      M. Masotta, S. Mollo, C. Freda, M. Gaeta, G. Moore, Contrib. to Mineral. Petrol., 2013, DOI:10.1007/s00410-013-0927-9.
A regional atmospheric warming threshold for irreversible Greenland ice sheet mass loss
Authors: van den Broeke Michiel , Noël Brice , van Kampenhout Leo , van de Berg Willem-Jan
Published: March 2020

The mass balance of the Greenland ice sheet (GrIS, units Gt per year) equals the surface mass balance (SMB) minus solid ice discharge across the grounding line. As the latter is definite positive, an important threshold for irreversible GrIS mass loss occurs when long-term average SMB becomes negative. For this to happen, runoff (mainly meltwater, some rain) must exceed mass accumulation (mainly snowfall minus sublimation). Even for a single year, this threshold has not been passed since at least 1958, the first year with reliable estimates of SMB components, although recent years with warm summers (e.g. 2012 and 2019) came close. Simply extrapolating the recent (1991-present) negative SMB trend into the future suggests that the SMB = 0 threshold could be reached before ~2040, but such predictions are extremely uncertain given the very large interannual SMB variability, the relative brevity of the time series and the uncertainty in future warming. In this study we use a cascade of models, extensively evaluated with in-situ and remotely sensed (GRACE) SMB observations, to better constrain the future regional warming threshold for the 5-year average GrIS SMB to become negative. To this end, a 1950-2100 climate change run with the global model CESM2 (app. 100 km resolution) was dynamically downscaled using the regional climate model RACMO2 (app. 11 km), which in turn was statistically downscaled to 1 km resolution. The result is a threshold regional Greenland warming of close to 4 degrees. We then use a range of CMIP5 and CMIP6 global climate models to translate the regional value into a global warming threshold for various warming scenarios, including its timing this century. We find substantial differences, ranging from stabilization before the threshold is reached in the RCP/SSP2.6 scenarios with a limited but still significant sea-level rise contribution (< 5 cm by 2100) to an imminent crossing of the warming threshold for the RCP/SSP8.5 scenarios with substantial and ever-growing contributions to sea level rise (> 10 cm by 2100). These results stress the need for strong mitigation to avoid irreversible GrIS mass loss. We finish by discussing the caveats and uncertainties of our approach.
Reaction-induced strain localisation in garnet pyroxenites during mantle corner flow: an example from the Ulten Zone (Eastern Alps, N Italy)
Authors: Zanchetta Stefano , Menegon Luca , Pellegrino Luca , Tumiati Simone , Malaspina Nadia
Published: March 2020

In the Ulten Zone (Tonale nappe, Eastern Alps, N Italy), numerous peridotite bodies occur within high-grade crustal rocks. Peridotites show a transition from coarse protogranular spinel-lherzolites to fine-grained mylonitic garnet-amphibole peridotites (Obata and Morten, 1987). Pyroxenites veins and dikes, transposed along the peridotite foliation, show a similar evolution from coarse garnet-free websterites to fine-grained garnet + amphibole clinopyroxenites (Morten and Obata, 1983). This evolution has been interpreted to reflect cooling and pressure increase of pyroxenites and host peridotites from spinel- (1200 °C, 1.3-1.6 GPa) to garnet-facies conditions (850 °C and 2.8 GPa) within the mantle corner flow (Nimis and Morten, 2000).

The newly formed garnet occurs as exsolution within porphyroclastic, high-T pyroxenes, and crystallises along the pyroxenite and peridotite foliation.

Textural evidence and crystallographic orientation data indicate that the transition from spinel- to garnet-facies conditions was assisted by intense shearing and deformation. Pyroxene porphyroclasts in garnet clinopyroxenites show well-developed crystallographic preferred orientation (CPO), high frequency of low-angle misorientations, and non-random distribution of the low-angle misorientation axes. These features indicates that pyroxene porphyroclasts primarily deform by dislocation creep on the (100) [010] slip system. Dislocation creep is accompanied by subgrain rotation recrystallisation, which promotes the formation of new, smaller and equant pyroxene grains around porphyroclasts. The grain size reduction promotes a switch in the deformation mechanism from grain-size insensitive creep (i.e. dislocation creep) in the porphyroclasts to grain-size sensitive (GSS) creep in the small recrystallised grains. The switch from dislocation to GSS creep is accompanied not only by grain size reduction of pyroxenes, but also by the formation of garnet exsolutions in pyroxenes and garnet crystallisation along foliation. We suggest that garnet crystallisation triggers the pinning of the recrystallised matrix, stabilising the fine-grained microtexture for GSS creep process, and finally contributes to the rheological weakening of pyroxenites.

Pyroxenites and peridotites of Ulten Zone thus offer a unique opportunity to investigate the effects of mantle deformation and weakening on the processes that control the material exchange between crust and mantle at subduction zones.

 

Morten, L., & Obata, M. (1983). Bulletin de Minéralogie, 106(6), 775-780.

Nimis, P. & Morten, L. (2000). Journal of Geodynamics, 30(1-2), 93-115

Obata, M., & Morten, L. (1987). Journal of Petrology, 28(3), 599-623.
Dynamic and Interactive Scientific Posters: Visualising 3D Models and Simulation Data Using AR
Authors: Payton Ryan L
Published: March 2020

Researchers often have to carefully select data for figures to best show their results for a static 2D format such as a conference poster or outreach handout. This can result in the scientific message being harder to understand or only part of the story being visualised. Augmented reality can help in improving the clarity of temporal data as well as the understanding of 3D structures which may be challenging to otherwise visualise.

A series of software packages may be used in order to take video files (MP4, AVI etc…) and 3D model files (OBJ, STL, PLY etc…) and pair them with a target image, detectable by a mobile app for Android or iOS. The Vuforia engine plug-in for Unity allows for target images to be imported for use with AR and paired with a 3D model or video in Unity. Manipulation of the AR element is achieved using the Lean-Touch asset in Unity, allowing for scaling, rotation and movement.

The incorporation of AR in science communication at a professional and public level creates a memorable interaction which is also enriched by greater  scientific clarity. The interactive element of AR, especially using Lean-Touch, makes it an appealing tool for the public and children which results in greater engagement with science. The ability to show more data such as full simulations or experiment time lapses rather than a select series of still images also makes this an appealing tool for researchers in a variety of fields including modellers, experimentalists and anyone using digital data.