bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrating the Urban Canopy Layer in a Lagrangian Particle Dispersion Model
Authors: Stöckl Stefan , Rotach Mathias W. , Kljun Natascha
Published: March 2021

Traditional Lagrangian particle dispersion models reflect particles at the zero-plane displacement height and therefore cannot properly take near-ground effects into account. In this study, we investigate whether including the urban canopy layer improves the performance of such a Lagrangian particle dispersion model. Here, spatially averaged flow and turbulence profiles throughout the urban canopy are constructed based on data from the literature (mostly from wind tunnel and numerical modeling studies).

We apply a first-order approach to test to what degree the explicit inclusion of the urban canopy changes the simulated concentration distributions. In a comprehensive sensitivity study, we show that most of the parameters introduced to describe the turbulence and flow profiles in the canopy have a relatively minor impact on the dispersion (and hence concentration distribution) – despite their inherent uncertainty. In particular, concentration fields are more sensitive to previously existing parameters of the model. One exception is a parameter describing the mean canopy wind speed profile, to which the model is sensitive.

When compared to data from the BUBBLE tracer experiment, the results show that the inclusion of the urban canopy layer slightly improves the modelled concentration values. The improvement is minor and might likely differ when comparing with other field experiments. However, the key point here is that the increased complexity and added capability of near-ground concentration simulation did not fundamentally change the model performance.

Ultimately, inclusion of the urban canopy layer will allow the model to be used as the dispersion core for an urban footprint model with footprint estimates near the ground.
The importance of accounting vegetation on unsaturated slopes prone to rainfall-induced instabilities – a case study in Norway
Authors: Piciullo Luca , Capobianco Vittoria , Heyerdahl Håkon
Published: March 2021

In unsaturated steep slopes, the upper unsaturated zone may have a crucial role in the slope stability. In this work we studied a natural slope located adjacent to a railway track in Eastern Norway. Due to its steep inclination, the factor of safety should be always kept under observation. In addition, the climate in Norway is expected to become wetter and warmer, with increased snow melting. Thus the rainfall/snowmelt infiltration play an important role and needs to be monitored properly to avoid any failure. The slope is instrumented since 2016 and both volumetric water content (VWC) and the pore water pressure regime are monitored.

The modulus SEEP/W of the commercial software GeoStudio (GEO-SLOPE International, Ltd.) was used to model the transient seepage conditions of the slope for a 7-month monitoring period (from June 2019 to December 2019). Several analyses were carried out by changing the initial conditions and the boundary climate conditions of the slope. Regarding the initial conditions, two series of simulations were carried out, one with an initial calibration of the VWC distribution, another one without calibration, hence, by only locating the ground water table at a specific depth and by indicating the maximum negative head (as required by the model). The calibration, instead, consisted in starting the simulation considering a VWC distribution as closer as possible to the in-situ value.

For each series, a total of three simulations were carried out with different boundary climate conditions, respectively considering only rainfall/snowmelt (R), considering both rainfall/snowmelt and evaporation (Cl), and considering rainfall/snowmelt and evapotranspiration due to vegetation (V). Indeed, the slope is all covered by relatively dense vegetation, with shrubs and birch trees. For the simulations including evaporation and vegetation (Cl and V), the land-climate interaction boundary condition was adopted. Climate functions, such as the pairs temperature-time, relative humidity-time, wind speed-time, were obtained from a close meteorological station. The evaporation was determined by using the Penman-Monteith equation, including vegetation features in the case of vegetated slope. Preliminary results show that the initial calibration is important for the correct back-analyses of the measured data, and that the model is more accurate when accounting for climate boundary conditions and vegetation, which influence also the slope stability conditions.

The work has been part of the working package "Landslide triggered by hydro-meteorological processes" within the Center for Research-based Innovation (CRI) programme KLIMA2050 (), financed by the Research Council of Norway.
Machine Learning applied to Lunar Data to Characterize Potential Sites for Future Science, Mobile Exploration, Utilization, lunar Bases and Moon Villages.
Authors: den Heijer Daniël , Foing Bernard
Published: March 2021

The lunar south pole is of particular interest to researchers because of its unique geographical features. It contains craters where the near-constant sunlight does not reach the interior. These craters are of enormous importance in the process of human exploration of the moon.This research aims to develop an identification algorithm applied to LROC data to characterize and identify potential regions of interest on the lunar south pole. Such areas of interest include (surroundings of) lava tubes, skylights, crater detection for age estimation, and planning traverses for the Artemis successive missions.Identifying these regions will be done using machine learning techniques such as a deep convolutional neural network that will be trained on labeled data and are then used to identify and characterize new regions of interest.
A systematic approach for modeling global VTEC using machine learning
Authors: Kume Karolina , Zhelavskaya Irina , Shprits Yuri , Smirnov Artem , Vasile Ruggero , Bianco Stefano
Published: March 2021

Ionosphere is the ionized layer of the Earth’s upper atmosphere. Vertical total electron content (VTEC) is a highly descriptive measure of the ionosphere. Modeling and predicting VTEC is crucial, because its disturbances are indicative of severe effects in GPS signal propagation and radio communication. We present a new neural-network-based model of VTEC parametrized with geomagnetic indices, solar wind and their time histories. The model was extensively validated with nested cross-validation to ensure that it performs well during geomagnetic storms and quiet times. We applied a number of feature selection methods, namely gradient boosting, permutation feature importance, random forests and cross-correlation. We selected the best input parameters to the model. In addition to reducing dimensionality and avoiding overfitting, the proposed approach also allows to get physical insights into the dynamics of the ionosphere. 
Filtration by porous media: a microfluidics approach
Authors: miele filippo , dentz Marco , morales Veronica , de Anna Pietro
Published: March 2021

The transport of colloids in porous media is governed by deposition on solid surfaces and pore-scale flow variability. Classical approaches, like colloid filtration theory (CFT), do not capture behaviours observed experimentally, such as non-exponential steady state deposition profiles and heavy tailed BreakThrough Curves (BTC). In the framework of CFT, a key assumption is that the colloid attachment rate 𝑘 is constant and empirically estimated via a posteriori macroscopic data fitting. We design a novel experimental set-up based on time-lapse microscopy and continuous injection of fluorescent monodisperse colloids into a folded microfluidics device (1mt total length) designed with a controlled level of 2D spatial disorder. This set-up allows us to i) measure both BTC and deposition profile over several orders of magnitude and ii) to perform particle tracking and Lagrangian analysis of single colloid's trajectories. Based on this analysis, we propose a stochastic model that takes into account pore scale heterogeneities in terms of correlation length, velocity and attachment rate distribution, that captures the anomalous behaviour shown by the experimental data.
Thermodynamic modelling and simulation of geothermal power plants: case studies and environmental impact
Authors: Colucci Vitantonio , Damone Angelo , Manfrida Giampaolo , Fiaschi Daniele
Published: March 2021

The emissions associated with Geothermal power plant (GTPP) due to geothermal fluids represents a compelling challenge addressed in the last decades. The on-line measuring of pollutants generated by GTPP might result in a complicated task to handle. Simulation of GTPP has become an excellent tool to monitor and control the emission of pollutants. In the present work, the pollutant emissions of GTPP of Hellisheidi (Island), Chiusdino, and Castelnuovo (Italy) are modelled and developed with Unisim Design R480 using well understood thermodynamical models implemented in OLI. The presence of brine in the thermodynamical models has been taken into account. Carbon dioxide, methane, and hydrogen sulfide are the chemical pollutants considered for the process simulation. The AQ framework model in OLI is being used for binary mixtures and non-condensable gas. Furthermore, for liquid mixtures containing more than two components, the MSE-SRK Thermodynamic model is desirable depending on the original geothermal fluid source. The simulation process outcome agrees with experimental data for pressure between 30 and 100 bar within 5% deviation. A systematic study of the spatial distribution of the emissions has been made for the area surrounding the GTPP. Furthermore, an economic evaluation overview has been performed to highlight the equipment needed for maintenance and tool substitution.
10 July 1894 Istanbul Earthquake: Comparing Damages and Ground Motion Simulations
Authors: Yenihayat Nesrin , Çaktı Eser , Şeşetyan Karin
Published: March 2021

One of the major earthquakes that resulted in intense damages in Istanbul and its neighborhoods took place on 10 July 1894. The 1894 earthquake resulted in 474 losses of life and 482 injuries. Around 21,000 dwellings were damaged, which is a number that corresponds to 1/7 of the total dwellings of the city at that time. Without any doubt, the exact loss of life was higher. Because of the censorship, the exact loss numbers remained unknown. There is still no consensus about its magnitude, epicentral location, and rupture of length. Even though the hardness of studying with historical records due to their uncertainties and discrepancies, researchers should enlighten the source parameters of the historical earthquakes to minimize the effect of future disasters especially for the cities located close to the most active fault lines as Istanbul. The main target of this study is to enlighten possible source properties of the 1894 earthquake with the help of observed damage distribution and stochastic ground motion simulations. In this paper, stochastic based ground motion scenarios will be performed for the 10 July 1894 Istanbul earthquake, using a finite fault simulation approach with a dynamic corner frequency and the results will be compared with our intensity map obtained from observed damage distributions. To do this, in the first step, obtained damage information from various sources has been presented, evaluated, and interpreted. Secondly, we prepared an intensity map associated with the 1894 earthquake based on macro-seismic information, and damage analysis and classification. For generating ground motions with a stochastic finite fault simulation approach, the EXSIM 2012 software has been used. Using EXSIM, several scenarios are modeled with different source, path, and site parameters. Initial source properties have been obtained from findings of our previous study on the simulation of the 26 September 2019 Silivri (Istanbul) earthquake with Mw 5.8. With the comparison of spatial distributions of the ground motion intensity parameters to the obtained damage and intensity maps, we estimate the optimum location and source parameters of the 1894 Earthquake.
Geostructural mapping of the Discovery Quadrangle (H-11), Mercury
Authors: Galluzzi Valentina , Ferranti Luigi , Giacomini Lorenza , Palumbo Pasquale
Published: March 2021

The Discovery quadrangle of Mercury (H-11) located in the area between 22.5°S–65°S and 270°E–360°E encompasses structures of paramount importance for understanding Mercury’s tectonics. The quadrangle is named after Discovery Rupes, a NE-SW trending lobate scarp, which is one of the longest and highest on Mercury (600 km in length and 2 km high). By examining the existing maps of this area (Trask and Dzurisin, 1984; Byrne et al., 2014), several other oblique trending structures are visible. More mapping detail could be achieved by using the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Mercury Dual Imaging System (MDIS) imagery. We aim at mapping the structures of H-11 at high-resolution by using MESSENGER/MDIS basemaps, in order to understand its regional tectonic history by following the work done in the Victoria quadrangle (H-2) (Galluzzi et al., 2019). Differently from H-2, located in the same longitudinal range but at opposite latitudes, this area lacks in N-S trending scarps, such as the Victoria-Endeavour-Antoniadi fault system, which dominates the northern hemisphere structural framework. The existing tectonic theories predict either an isotropic pattern of faults (global contraction) or an ordered distribution and orientation of faults (tidal despinning) for Mercury. If we expect that the existing tectonic patterns were governed by only one of the two processes or both together, it is difficult to understand how such different trends formed within these two complementary areas. The structural study done for H-2 reveals that the geochemical discontinuities present in Mercury’s crust may have guided and influenced the trend and kinematics of faults in that area (Galluzzi et al., 2019). In particular, the high-magnesium region seems to be associated with fault systems that either follow its boundary or are located within it. These fault systems show distinct kinematics and trends. The south-eastern border of the HMR is located within H-11. Hence, with this study, we aim at complementing the previous one to better describe the tectonics linked to the presence of the HMR. Furthermore, this geostructural map will complement the future geomorphological map of the area and will be part of the 1:3M quadrangle geological map series which are being prepared in view of the BepiColombo mission (Galluzzi, 2019). Acknowledgements: We gratefully acknowledge funding from the Italian Space Agency (ASI) under ASI-INAF agreement 2017-47-H.0.

 

Byrne et al. (2014). Nature Geoscience, 7(4), 301-307.

Galluzzi, V. (2019). In: Planetary Cartography and GIS (pp. 207-218). Springer, Cham.

Galluzzi et al. (2019). Journal of Geophysical Research: Planets, 124(10), 2543-2562.

Trask and Dzurisin (1984). USGS, IMAP 1658.
Applying the socio-ecological approach to biocrust research: a call for scientific action
Authors: Maggioli Lisa , Lopez Rodriguez Maria , Chamizo Sonia , Cantón Yolanda , Rodriguez-Caballero Emilio
Published: March 2021

Biocrusts play a key role in maintaining drylands ecosystems at the global scale. These keystone communities face important human[ERC1]  threats (e.g. climate change) that can result in both biocrust coverage loss and community composition changes and are expected to negatively affect soil biodiversity, and the functioning and resilience of drylands ecosystems. In this adverse scenario, there is an urgent need to develop legal science-based frameworks that underpin their protection. The social-ecological approach, as a research framing oriented to produce scientific knowledge able to properly inform policy actions and management practices, can help us to advance in this direction. By reviewing literature in Spanish biocrusts from the social–ecological approach, here we found that the ecological scope

of biocrust has been widely studied in the last decades; however, the social dimension of their role remained unexplored. In addition, we identified knowledge gaps and new research areas that need to be addressed in order to (1) produce research that better informs policy and society about the role of these keystone communities, and (2) promote the best available evidence on the biocrusts role which can be used to support conservation actions. On this basis, we call for a transition from an “ecological research perspective” to a “social–ecological research perspective” into the biocrust area in order to promote evidence-based conservation practices that contribute to the preservation of these representative communities of drylands all over the world.
Investigation of Foehn Events on South Georgia Island using Meteorological Surface Data and GNSS Precipitable Water Vapour
Authors: Erkihune Eshetu , Hunegnaw Addisu , Teferle Felix Norman
Published: March 2021

As one of the most important components of the global hydrologic cycle, atmospheric water vapor shows significant variability in both space and time over a large range of scales. This variability results from the interactions of many different factors, including topography and the presence of specific atmospheric processes. One of the key regions for affecting global climatic variations lies in the sub-Antarctic zone over the Southern Ocean with its Antarctic Circumpolar Current and the associated Antarctic Convergence. There, in this cold and maritime region, lies South Georgia Island with its weather and climate being largely affected by both the dominating ocean currents and the westerly winds in this zone. While the island forms an important outpost for various surface observations in this largely under sampled and extremely remote region, it also forms a barrier for these winds due to its high topography. This, in turn, leads to various local meteorological phenomena, such as warm Foehn winds, which have a significant impact on the near-surface meteorology and contribute to the accelerated glacier retreat observed for the northeast of the island.

Surface meteorological data have been available for several stations near King Edward Point (KEP) in South Georgia for much of the 20th century. Since 2013 and 2014, Global Navigation Satellite System (GNSS) data have been available at five locations around the periphery of the island. In this study, we investigate the consistency between the different surface meteorological data sets and along with GNSS Precipitable Water Vapour we use these to analyse historic Foehn events.

 
Numerical and laboratory studies of magnetic enhancements produced by solar wind interaction with Lunar crustal magnetic fields
Authors: Divin Andrey , Shaikhislamov Ildar , Rumenskikh Marina , Zaitsev Ivan , Semenov Vladimir , Deca Jan , Korovinskiy Daniil
Published: March 2021

In this study, we use a combination of 3D Particle-in-Cell (PIC) simulations and a laboratory experiment to investigate the dynamics of solar wind - Moon interaction. It is known that the Moon has no global magnetic field, but there exist areas of intense remanent magnetization of the lunar crust which are strongly non-dipolar. Performed simulations indicate that the localized crustal fields are capable of scattering solar wind ions, efficiently heat electrons, and produce magnetic field perturbations in the upstream plasma. Numerical study of reflected ion flux compares well to the laboratory experiment performed at induction discharge theta-pinch "KI-1" facility (Novosibirsk). The plasma flow interacts with a magnetic field source (dipolar or quadrupolar), producing a minimagnetosphere with typical scales comparable to (or less than) a few ion inertial lengths. Our numerical and laboratory study concludes that the magnetic field should drop faster than r-3 with the distance in order to reproduce the spacecraft observations. In this case, gyroradii of the reflected ions are considerably larger than the scale of the minimagnetosphere density cavity. Reflected ions generate enhancements in the upstream magnetic field, supposedly seen as LEMEs (lunar external magnetic enhancements) in spacecraft data above the Moon crustal fields.
Fluorescence property of solvent extractable organic aerosol in a cold-temperate forest area of Japan
Authors: Afsana Sonia , Miyazaki Yuzo , Tachibana Eri , Deshmukh Dhananjay Kumar , Kawamura Kimitaka , Mochida Michihiro
Published: March 2021

Organic aerosol (OA), a major component of atmospheric aerosol, is considered to be one of the key players in atmospheric radiative balance and climate change. Chromophoric OA, termed as brown carbon (BrC), is a component that can absorb solar radiation in the ultraviolet and short-wavelength visible regions and is composed of a wide range of poorly characterized compounds. Whereas light absorption properties were analyzed to characterize chromophoric OA, fluorescent properties also provide information on them. In this study, the fluorescence property of solvent extractable organics in submicron aerosol particles collected in a forest in the cool-temperate zone of northern Japan, was characterized.

Aerosol samples were collected on quartz filters (cut-off diameter: ≤0.95 micrometer) in Tomakomai Experimental Forest of Hokkaido University. Organic aerosol components in the samples were extracted and fractionated on the basis of their polarity by the combination of solvent extraction and solid-phase extraction methods. Water-soluble organic matter (WSOM) and water-insoluble organic matter (WISOM) were extracted sequentially by using multiple solvents. Two fractions, humic-like substance (HULIS) and highly-polar water-soluble organic matter (HP-WSOM), were fractionated from WSOM by solid phase extraction. The excitation−emission matrices (EEMs) were measured using a fluorescence spectrometer, and the fluorescence property of the extracts was characterized by the classification of EEM profiles using a Parallel Factor (PARAFAC) model.

From the PARAFAC analysis, five types of fluorescent components were identified for each of WSOM and WISOM fractions. A fluorescence component with the characteristics reported to be associated with (HULIS) accounted for large fractions of the fluorescence from WSOM and WISOM (mean: 68% and 84%, respectively). The relative contribution of the fluorescent components for WSOM shows a clear seasonal variation of the characteristics of WSOM. Furthermore, from each of HULIS and HP-WSOM fractions, five types of fluorescent components were identified. Fluorescence components with the characteristics of protein-like compounds identified in previous EEM studies accounted for a large fraction of the fluorescence from HP-WSOM (mean: 53%), whereas the contribution of protein-like compounds was smaller in the case of the HULIS fraction (mean: 23%).
Effect of dead-end pores on anomalous transport in porous media
Authors: Bordoloi Ankur , Scheidweiler David , de Anna Pietro
Published: March 2021

Heterogeneity in porous media may occur due to non-uniformity in the sizes or the shapes of grains that comprise the medium. We investigate the transport of colloids in a heterogeneous porous medium engineered in microuidic channels and featuring complex grain structures. Using experiment and numerical simulation, we investigate the velocity fields and the breakthrough curves of colloidal transport in a model porous medium by emphasising on the effects of dead-end pores. We characterize the porous structure via image processing and isolate dead-end sites from the remaining pore spaces. The study reveals complex flow structures inside dead-end sites that contribute to the small-scale velocity and long tails in the breakthrough curve. We provide a statistical model to capture the complex dynamics of the breakthrough curve.
Modelling aspects of the sulfate aerosol evolution after recent volcanic activity
Authors: Brodowsky Christina , Sukhodolov Timofei , Feinberg Aryeh , Höpfner Michael , Peter Thomas , Stenke Andrea , Rozanov Eugene
Published: March 2021

Volcanic activity is one of the main natural climate forcings and therefore an accurate representation of volcanic aerosols in global climate models is essential. However, direct modelling of sulfur chemistry, sulfate aerosol microphysics and transport is a complex task involving many uncertainties including those related to the volcanic emission magnitude, vertical shape of the plume, and observations of atmospheric sulfur. This study aims to investigate some of these uncertainties and to analyse the performance of the aerosol-chemistry-climate model SOCOL-AERv2 for three medium-sized volcanic eruptions from Kasatochi in 2008, Sarychev in 2009 and Nabro in 2011. In particular, we investigate the impact of different estimates for the initial volcanic plume height and its SO2 content on the stratospheric aerosol burden. The influence of internal model variability and of modelled dynamics is addressed by three free-running simulations and two nudged simulations at different vertical resolutions. Comparing the modelled evolution of the stratospheric aerosol loading and its spread with the Brewer-Dobson-Circulation (BDC) to satellite measurements reveals in general a very good performance of SOCOL-AERv2 during the considered period. However, the large spread in emission estimates logically leads to significant differences in the modelled aerosol burden. This spread results from both the uncertainty in the total emitted mass of sulfur as well as its vertical distribution relative to the tropopause. An additional source of modelled uncertainty is the tropopause height, which varies among the free-running simulations. Furthermore, the validation is complicated by disagreement between different observational datasets. Nudging effects on the tropospheric clouds were found to affect the tropospheric SO2 oxidation paths and the cross-tropopause transport, leading to increased background burdens both in the troposphere and the stratosphere. This effect can be reduced by nudging only horizontal winds but not temperature. A higher vertical resolution of 90 levels (as opposed to 39 in the standard version) increases the stratospheric residence time of sulfate aerosol after low-latitude eruptions by reducing the diffusion speed out of the tropical reservoir. We conclude that the model's uncertainties can be largely defined by both its set-up as by the volcanic emission parameters.
The evolution of Jupiter polar cyclones
Authors: Mura Alessandro , Plainaki Christina , Sindoni Giuseppe , Adriani Alberto , Grassi Davide , Moriconi Marisa , Ciarravano Alessandro , Piccioni Giuseppe , Migliorini Alessandra , Sordini Roberto
Published: March 2021

JIRAM (the Jovian InfraRed Auroral Mapper) is an infrared camera and
spectrometer on board Juno. JIRAM operates in the 2-5 μm spectral
range and is built to observe both Jupiter's infrared aurora and its
atmosphere. Since 2016, JIRAM has performed several observations of
the polar regions of the planet, thanks to the unique orbital design
of the Juno mission.  In the north polar region, Juno discovered, in
2017, the presence of an eight-cyclone structure around a single polar
cyclone; to the south, a polar cyclone is surrounded by five
circumpolar cyclones. The stability of these structures has been
monitored for almost 4 years. Recent observations, made at the end of
2019, showed that the configuration of the South Pole has temporarily
changed: the structure moved in a hexagon for a few months, before
returning to its original pentagonal shape. To the north, there are
significant hints that the octagonal shape may have been lost for a
similar period of time.
We find that all cyclones show a very slow, westward drift as a rigid
ensemble, and, in addition, they oscillate around their rest position
with similar timescales. These oscillations seem to propagate from
cyclone to cyclone. The implications of these transient deviations
from the symmetrical forms, which appear to be an apparent condition
of equilibrium, are discussed.
A European Fault Database as a stepping stone towards improved subsurface evaluation of hazards and resources
Authors: Van Gessel Serge , van Ede Rob , Doornenbal Hans , ten Veen Johan , Hintersberger Esther ,   HIKE Team
Published: March 2021

Faults are prominent features in the subsurface that define the geological development and distribution of geological formations and resources therein. Faults can define resources themselves (e.g. minerals, thermal conduits), but more often they can pose a hazard to subsurface drilling, injection and extraction activities . Well-known examples are Basel – Switzerland (geothermal stimulation), Oklahoma – US (waste water injection) and Groningen – The Netherlands (conventional hydrocarbon extraction).

Despite that faults are a typical product of geological mapping, there was, until now, no consistent insight in these structures in a pan-European context. There are some examples focusing on the publication of seismogenic faults (e.g. GEM Global Active Faults Database, SHARE  European Database of Seismogenic Faults, USGS Quaternary faults database), yet deeply buried faults are under-represented here. With the European fault database, the GeoERA-HIKE project addresses the following objectives: i) develop a consistent and uniform repository for fault data and characteristics across Europe, ii) Implement an associated tectonic vocabulary which provides a framework for future interpretation, modelling and application of fault data, and iii) assess the applicability of fault data in case studies.

The current fault database is envisioned to be a major stepping stone for a sustained and uniform development and dissemination of tectonic data and knowledge which will be applicable to a broad spectrum of subsurface research challenges. The database contains data from Geological Survey Organizations and partners in the Netherlands, Germany, Austria, Belgium, Iceland, Denmark, Poland, Lithuania, Italy, France, Ukraine, Portugal, Slovenia, Albania and various countries in the Pannonian Basin Area.

The GeoERA-HIKE project has received funding from the European Union’s Horizon 2020 research and innovation programme under agreement No. 731166
Ecosystem-based approach towards the sustainable management of coastal engineering: compensation and mitigation measures applied to the Civitavecchia harbour
Authors: Marcelli Marco , Scanu Sergio , Madonia Alice , Bonamano Simone , Fersini Giorgio , Piermattei Viviana
Published: March 2021

The expansion of Civitavecchia Hub Port will potentially produce an impact on the adjacent coastal areas which are characterized by the presence of SCIs (Sites of Community Importance IT6000005 northern and IT6000006 southern to the port area) which extend in front of the municipalities of Tarquinia, Civitavecchia and Santa Marinella.
The two SCIs are characterized by priority habitats and species under the Habitat Directive 92/43 / EEC; in particular, they host Posidonia oceanica meadows (Priority habitat 1120 * - Posidonion oceanicae) and coralligenous bioconstructions (Habitat 1170 - Reefs), as well as individuals of Pinna nobilis (Annex IV - Habitat Directive Code 1028) and colonies of Corallium rubrum ( Annex IV - Habitat Directive Code 1001).
Within VIA and VAS procedures, a series of complex activities has been implemented to reduce the potential impacts on the marine environment, leading to the presentation of an innovative ecosystem-based program of mitigation and compensation measures based on the assessment of direct and indirect impacts of construction activities as well as ecosystem services analysis. This new program is based on our project "Ecosystem-based approach applied to the evaluation of compensation and mitigation measures in marine environment: The case study of the Port Hub of Civitavecchia". The project includes for example: a detailed analysis of marine habitats and oceanographic conditions, restoration of equivalent habitats, habitats and species protection systems, actions towards an eco-sustainable use of the environment. The innovation of this approach derives from the quantification of the interventions which is based on the assessment of surfaces damage as well as on the uses affected both directly and indirectly, considering a time interval of ten years for the recovery of the damaged ecosystem functions.
Impacts of climatic seasonality on weathering of rock-cut structures at Lalibela, Ethiopia
Authors: Taye Blen , Viles Heather
Published: March 2021

Weathering of rock-cut structures exposed to the environment is strongly influenced by fluctuations in climatic variables. Both macro and microclimate data are needed to identify key weathering types and rates likely to affect rock-cut structures in a specific region. The aim of this paper is to study the macro and micro climatic conditions affecting the rock-cut churches in Lalibela, Ethiopia to determine how the climate influences weathering at this site. Macro climate data collected over a 26-year period and microclimate data monitored on the north, east, south and west walls at one of the churches in the Lalibela church complex (Bete Mariam) are used to make these assessments. Microclimate data was monitored during the long rains (Kiremt), short rains (Belg) and dry (Bega) seasons in 2018 and 2019. The results showed a high seasonal variation in macro climatic conditions like rainfall and ambient relative humidity. The micro climatic (rock surface) conditions also tended to vary seasonally. The diurnal range of rock surface temperature during Bega varied significantly depending on which cardinal directions the walls were facing, with south and west facing walls having high diurnal thermal ranges. The influence of aspect was less pronounced in Belg and Kiremt, but cloud cover played an important role in varying the range of diurnal thermal and humidity cycles from day to day during these seasons. These climate trends are likely to cause seasonal variations in wetting and drying cycles, deep wetting, increased time of wetness and thermal cycling. These wetting/drying and heating/cooling characteristics affect weathering processes. During Kiremt, biological weathering, salt weathering and clay swelling are more likely to occur than in Belg and Bega. High diurnal thermal ranges in Bega are likely to cause thermal fatigue in this season. This is the first paper to address the macro and micro climatic trends that influence rock weathering at the rock-cut churches in Lalibela. The results of this study also have implications for rock-cut structures in northern Ethiopia having similar environmental conditions as Lalibela.
OpenDroneMap360, an affordable DIY open-source hardware and software workflow for 3D point clouds and terrain models
Authors: Winsemius Hessel , Mather Stephen , Gayton Ivan , Chazua Iddy
Published: March 2021

The state of the art in terrain data generation is Light Detection And Ranging (LiDAR). LiDAR is usually deployed through manned or unmanned aerial vehicles. As typical payloads are high, an aircraft with LiDAR needs to be significant in size. Therefore, LiDAR is currently only done by specialized companies with expensive equipment, and cannot be deployed by local service providers in low income countries, despite the plethora of use cases for its data.

 

A promising avenue to replace LiDAR is photogrammetry. It can be applied with much lighter and more affordable aircrafts and its use to provide extensive terrain datasets is steadily increasing. The scalable open-source software OpenDroneMap allows for extending datasets to very large amounts. Photogrammetry however, cannot penetrate vegetation, and (as is the case with LiDAR) does not resolve ground terrain in obscured areas such as dense urban areas with narrow alleys.

 

That is why we are developing OpenDroneMap360, a free and open-source DIY hardware-software camera-ball platform for collection of high quality photos with any carrier you can think of. This can be a self-built drone, a backpack rig or another setup we haven’t considered yet, equipped with enough lenses to discover any ground that you can think of. Our current hardware offers a backpack rig with a total of 7 lenses and contains a parts list, 3D-printable hull, connection scheme, software deployment and a Sphinx manual how to build, deploy and operate the rig. The technology contains raspberry pi cameras connected to raspberry pi zeros for each lens, a Ardusimple u-blox ZED-F9P GNSS chipset, a raspberry pi4 to instruct the cameras, collect GPS positions, and perform file and data management, and a LiPo battery solution. The entire setup is available on https://github.com/localdevices/odm360

 
Observation and modelling of the seismc high frequency PKPab precursor at distances larger than 155o
Authors: Sens-Schönfelder Christoph , Bataille Klaus , Bianchi Marcelo
Published: March 2021

Seismic waves traveling through the outer core have been used for a long time to study heterogeneity at the core mantle boundary (CMB) and in lower mantle. Earth's velocity structure opens a window for waves that are scattered at 3D structures in the lower mantle to arrive at the Earth's surface prior to the waves that would propagate in a 1D spherically symmetric model. These precursors are particularly well observed as they are not hidden in the coda waves of earlier phases. At epicentral distances below 140° PKPab and PKPbc waves scattered close to the CMB can arrive as precursors to PKPdf  that travels through the inner core (IC). These waves have been studied extensively and provided important information about the structure of the mantle close to the CMB. However, theory predicts that PKP waves can also be scattered to distances above 155°. These waves have not been well observed before, partly because they arrive at the surface only after the inner core PKPdf phase that has far larger amplitudes at lower frequencies. Here we report on the observation of an emergent arrival of seismic energy at distances above 155° that is consistent with the onset times of scattered PKPbc energy. The key to observe this scattered phase is the use of signals from large deep earthquakes which are strong high frequency sources. As basis for the observation we used records of the Japanese Hi-Net stations that allowed to observe the scattered waves in the distance range between 135o and 165o when combining records of two events in Peru and Argentina. The Brazilian seismic network provided observations of a deep Bonin Islands event in the distance range from 145o to 175o. Using frequencies around 6Hz we show (A) energy in this frequency band propagates to epicentral distances beyond 170°, (B) attenuation in the IC completely removes the energy of the PKPdf phase, (C) energy scattered close to the CMB arrives prior to PKPab wave forming a precursor that we call PKPab precursor. This observation extends the frequency range and opens a new time-distance window for investigations of deep Earth heterogeneity. 
Float Your Boat - Norway. School students, small wooden boats and marine research in the Arctic
Authors: Lygre Kjetil , Hallaråker Røsvik Bjørnar , Storheim Espen , Forcucci David , Rigor Ignatius , Langehaug Helene R. , Sagen Hanne , Pettersson Lasse H.
Published: March 2021

This communication project aims to increase our understanding of climate processes, the Arctic and the importance of research through the active involvement of primary to junior high school students. The project is based on NERSC's ongoing activity in the Arctic Sea, collaborating with several projects and utilizing a concept introduced by the US Coast Guard. Students of four primary schools in western Norway produced a total of 230 small wooden boats.  Together with a comparable number of boats produced by US students they were subsequently launched on the ice in the Arctic Ocean by the coast guard ship KV Svalbard in August and November 2020 as part of scientific cruises. Scientific buoys were also launched, transmitting their position and surface temperature. Through a dedicated web-site students and teachers could follow the drift in near real time. Boats are uniquely branded with a web address, so they may be reported if found after drifting ashore.

The project website serves both as a communication hub between scientists and students and teachers and to reach out to a wider audience. Several films were produced in this regard. Webinars were held by NERSC scientists on climate and ocean science topics and crew members from K/V Svalbard on work and life onboard a coast guard vessel. Feedback from the teachers will also be presented.
Quantification of biogeomorphic interactions between small-scale sediment transport and primary vegetation succession on proglacial slopes of the Gepatschferner, Austria
Authors: Haselberger Stefan , Ohler Lisa-Maria , Otto Jan-Christoph , Junker Robert R. , Glade Thomas , Kraushaar Sabine
Published: March 2021

Proglacial slopes provide suitable conditions to observe the co-development of abiotic and biotic systems. The frequency and magnitude of geomorphic processes and composition of plants govern this interplay, which is described in the biogeormorphic feedback window for glacier forelands. The study sets out to quantify small-scale sediment transport via mechanical erosion plots along a plant cover gradient and to investigate the multidirectional interactions between abiotic and biotic processes. We aim to generate quantitative data to test the biogeomorphic feedback window.

Small-scale biogeomorphic interactions were investigated on 30 test plots of 2 x 3 m size on proglacial slopes of the Gepatschferner (Kaunertal) in the Austrian Alps during snow-free summer months over three consecutive years. The experimental plots were established on slopes along a plant cover gradient. A detailed vegetation survey was carried out to capture biotic conditions and specific sediment yield was measured at each plot. Species abundance and composition at each site, as well as plant functional types reflected successional stages.

We observed a strong decline in geomorphic activity on plots with above 30% plant cover. Mean monthly rates of specific sediment yield decreased from 111 g m-2 to 37 g m-2. Non-metric multidimensional scaling showed distinct vegetation composition for the three stages of biogeomorphic succession. Quantified process rates and observed vegetation composition support the concept of biogeomorphic feedback windows. The findings help to narrow down a stage during succession where the importance of biotic processes start to dominate.
Insights of Spatiotemporal evolution of Yamuna Valley, Garhwal Himalaya: Derived from Fission track dating and Morphotectonic analysis
Authors: Gahlaut Prerna , Chandra Patel Ramesh
Published: March 2021

Substantial set of recent documentation with sophisticated statistical and analog models have recognized dynamic interchange between subsurface crustal distortion and exogenic erosional processes as the root of geomorphic evolution of Himalaya. Low temperature thermochronology provides insights to enumerate nature and timing of tectonic course from extracted thermal records of vertical moving rock block over geological past. In present study, we used Apatite fission track technique to calculated exhumation rates of Yamuna valley, Garhwal Himalaya. AFT ages of Lesser Himalaya Sequence of Purola region various between 4.0 ±0.8 myr to 9.5±0.6 myr. While AFT ages of LHS along Yamuna River varies form 2.3±0.5 myr to 5.6±0.6 myr and exhumation rates are 2.3-1.2 mm/yr. calculated age of Apatite sample near Main Central Thrust (MCT) is 2.3±0.5 myr which exhumed at the rate of 2.3 mm/yr. Exhumation rates of Purola region are 0.8-1.6 mm/yr.

To link the exhumation rates with present day morphology we used 2 methods; 1) Calculate morphotectonic parameters of Yamuna River valley; 2) compare our AFT ages and exhumation rates with early studies. Drainage pattern in the tectonically active zone is vigorously susceptible to mechanisms such as folding, faulting and basin tilting. Such deformation processes influence the phase of geomorphology, drainage pattern, river incision, elongation, asymmetry, and diversion. Mathematical quantification of drainage morphology elucidate spatio-temporal effect of tectonics. Morphotectonic parameters are stream length gradient index (SL), valley floor height to width ratio (Vf), asymmetry factor (Af), basin shape index (BS) and hypsometric integral (HI) extracted from SRTM DEM with resolution of 30m and are calculated in ArcGIS 10.3. These parameters further integrated to define a single Indaex of relative Active Tectonic (IRAT). Value of IRAT is very high in upper Yamunotri region and low to moderate in Purola region. The exhumation rates are further compared with erosion rates from early studies. Erosion rates derived from 10Be nuclides (Scherler et al 2014) show very slow erosion rate in Purola region (~ 0.13±0.01 mm/yr) while for Yamunotri region higher erosion rate (>4.9 mm/yr) is recorded. These erosion rates are attributed to subsurface geometry of MCT.

All three approaches together construct an evolution record of study area over geological past.  Exhumation history of Apatite and erosion rates from early studies conclude Yamuna river valley, specifically upper region of valley is very active while Purola region is less active. Morphotectonic parameters harmoniously present similar picture. These combined study point toward relegate control of climate and dominance of ongoing sub-surficial deformation along MCT in Yamuna River valley on geological time scale.