bluuebunny/crossref_metadata_2025 huggingface dataset:
Natural stones in the cities - an easy way to focus on rocks and geology
Authors: Ehling Angela , Heinz Ferdinand
Published: March 2022

Stones and thus building stones are very rarely in the focus of public interest. Geologists working with building stones use every opportunity to interest and sensitize people to this topic. Natural stones have served as building stones since time immemorial and they can be found in almost every town and village right before our eyes. They only need to be made visible to the viewer. Besides the explanation of the rocks, their petrographic and mineralogical composition, contained fossils and structures, technical features as well as their weathering behavior, one can point out many other aspects. This includes the geology of the area, geological timetable, mining, processing, transportation and use in past times and today, as well as aspects of restoration. Many geologists took and take advantage of this opportunity for geological and cultural education. They have written natural stone guides for several cities and organize natural stone excursions through their cities.

 

The German network “Stones in the city” has compiled a bibliography on this topic, which is constantly updated (www.steine-in-der-stadt.de). The bibliography contains just over 1100 entries on publications of dimension stones in cities worldwide. The time frame of the recorded publications is between the middle of the 19th century and the current year. The focus of this bibliographic collection includes the subject area of European building and decorative stones with a view of cultural geology. Some interesting aspects about the natural stone guides are presented in evaluation of this bibliography.
Preliminary results of Unidirectional Solidification Textures recorded by the aplite-pegmatites from Tres Arroyos (Badajoz, Spain) and the story they tell
Authors: Garate-Olave Idoia , Roda-Robles Encarnación , Gil-Crespo Pedro Pablo , Errandonea-Martin Jon , Pesquera Alfonso , Santos-Loyola Nora
Published: March 2022

One of the most characteristic attributes of pegmatitic rocks is their anisotropic fabric with a great variety of textures, including not only a broad range of crystal sizes, but also different types of unidirectional crystal growths such as the so-called Unidirectional Solidification Textures (UST). In the Tres Arroyos Pegmatite Field (Central Iberian Zone of the Iberian Massif), apart from comb-textures, the alternation of aplitic and pegmatitic layers (with variable modal proportions) parallel to the contacts with the host rocks occur commonly all across the pegmatitic dykes. The origin of the layering in these bodies is still enigmatic.

In the case of Tres Arroyos, the strong undercooling of the system could be produced by a combination of different factors, including a sudden drop of pressure favoring the exsolution of a fluxing components-bearing aqueous fluid from the pegmatitic melt, and a marked temperature decrease of the pegmatitic melt due to its intrusion into significantly colder host rocks. The reduced thickness of the studied dykes (average of 2 m) would promote to the development of nonequilibrium textures along the entire width of the dykes. The variation of the crystal size (≈2-3 orders of magnitude) through different layers constituting the dykes reflects changes in the nucleation density and crystal growth rate during crystallization. The occurrence of dykes with several alternating thin pegmatitic and aplitic layers could be the result of cyclical changes induced by the competition between crystal growth rate and nucleation rate. The simplest layering patterns observed in Tres Arroyos, with alternating quartz-rich and plagioclase-rich bands, or alternating lepidolite-rich and albite-rich layers, could be explained by a diffusion-controlled oscillatory nucleation model, whereas the understanding of more complex layering patterns would need a more comprehensive study.
Distribution and origin of submarine landslides in the active margin of the southern Alboran Sea (Western Mediterranean Sea)
Authors: d'Acremont Elia , Lafuerza Sara , Rabaute Alain , Lafosse Manfred , Jollivet Castelot Martin , Gorini Christian , Alonso Belen , Ercilla Gemma , Vazquez Juan Tomas , Vandorpe Thomas , Juan Carmen , Migeon Sébastien , Ceramicola Silvia , Lopez-Gonzalez Nieves , Rodriguez Mathieu , El Moumni Bouchta , Benmarha Oumnia , Ammar Abdellah
Published: March 2022

In the South Alboran Sea, the moderate seismicity (Mw=6.4) of the strike-slip Al Idrissi Fault Zone does not appear to control directly the landslides distribution. To provide a preliminary geohazard assessment, we characterized the spatial distribution, the volume and the ages of the submarine landslides from multibeam and seismic reflection data in the southern part of the Alboran Sea. Since the Quaternary numerous submarine landslide processes affect the marine sedimentary cover with volumes of the mass transport deposits (MTD) estimated between 0.01 to 15 km3.

West of the Al Idrissi Fault Zone, along the South Alboran Ridge’s northern flank, the distribution of the MTD follows the SW-NE bank and ridge trend that correlates with blind thrusts and folds covered by a plastered contourite drift. A pockmark field, related to fluid escape, is visible near landslide scars where the contourite drift is relatively thicker. In this area, landslide scars occur on variable slopes (2-24°) and their associated MTD have variable decompacted volumes (0.01-10km3). East of the Al Idrissi Fault Zone, between the Alboran Ridge and the Pytheas Bank, the mapped MTDs have uneven volumes. The smaller ones (<1 km3) have their slide scars on steep slopes (>10°), whereas those of the largest ones (3-15 km3) occur on gentler slopes (<5°).

These observations and a slope stability analysis suggest that the combination of seismic shaking, blind thrusts activity, relatively high sedimentation of contourite deposits, and fluid escape dynamics are likely the main controlling mechanisms rather than seismic shaking only. These causal factors would explain the concentration of landslide head scarps at the edge of the thickest parts of the contourite drifts (i.e. crests) may have been controlled locally by fluid overpressures in line with blind thrusts. Additionally, low to moderate seismicity potentially triggered by nearby faults might regionally have played a role in destabilising the seafloor sediments since 1.12 Ma, which coincides with the propagation of the Al Idrissi Fault Zone in the southern Alboran Sea. 
Ground-based remote sensing of aerosol properties using the Emission FTIR NYAEMFT and the Raman-Lidar KARL in Ny-Ålesund, Spitsbergen (78°N)
Authors: Ji Denghui , Palm Mathias , Ritter Christoph , Richter Philipp , Buschmann Matthias , Notholt Justus
Published: March 2022

Arctic amplification, the phenomenon that the Arctic is warming faster than the global mean is still not fully understood. The Transregional Collaborative Research Centre TR 172 -- Arctic Amplification: Climate Relevant Atmospheric and Surface Processes (AC3) funded by the DFG contributes towards this research topic.

This excessive Arctic warming is both a consequence and a driver of rapid changes in the Arctic and in part created by aerosol feedbacks. Since different aerosol types have different climate effects, the observation of aerosols is urgently needed in the Arctic. Thus, for the purpose of measuring aerosols in the troposphere, a Fourier-Transform InfraRed spectrometer (FTS) for measuring down-welling emission measurements and a Raman-Lidar are operated at the AWIPEV research base in Ny-Ålesund, Spitsbergen (78°N).

The height of the aerosol layer, aerosol backscatter, extinction, depolarization, the lidar ratio and the color ratio are measured by the Raman-Lidar. Based on that information, a retrieval algorithm, LBLDIS, for aerosol types (dust, sea salt, black carbon and sulfate), optical thickness and effective radius is modified and used for analyzing the emission spectra measured by the FTS.

Combining the two observations, the aerosols can be observed more comprehensively. The most probable origin of the dominant aerosol types is explored by tracking the origin of air masses through back-trajectory calculations using the FLEXPART atmospheric transport model.
Anisotropy of magnetic susceptibility (AMS) study of magma transport in Mount Calanna Dyke swarms of Mount Etna, Italy
Authors: Shajahan Rasia , Zanella Elena , Mana Sara , Harris Andrew , Van Wyk de Vries Benjamin
Published: March 2022

Dykes and Sills are the primary subvolcanic bodies that transport magma from the deep-seated magma reservoir or from the shallow magma chamber. The mechanism of magma transport and emplacement in dyke swarms is significant, as their passage from magma chamber through the crust to the surface or near-surface settings can provide valuable information on source and how magma has interacted with crustal rocks.

Here, we are presenting the preliminary findings obtained from the Anisotropy of Magnetic Susceptibility (AMS) and Palaeomagnetic analysis to study the magma transport mechanism and emplacement history of  Mount Calanna dyke swarms of Mount Etna. In order to find their magnetic fabrics, we systematically sampled 45 oriented hand samples from 11 dykes where at least two samples were collected from both dyke boundary and centre. Using the obtained AMS fabrics, we attempt to find the emplacement mechanisms of dykes in Mount Calanna and its relationship to Mount Etna.

AMS technique provides valuable information regarding the dyke emplacement such as whether the Mount Calanna dykes are feeders, and whether they are the result of polycentric, vertical or lateral magma flow. Based on the intersection of the AMS axis with the dyke plane, we were able to identify two classes, one where the dyke plane intersects with the maximum principal susceptibility axes (Kmax) and the other where the dyke plane intersects with the minimum principal susceptibility axes (Kmin). Nevertheless, the variation in the shape parameter from centre to boundary shows the effect of shear, magma viscosity and the host rock strength on magma emplacement. The Paleomagnetic techniques enable us to unravel the relative timing of the injection of the dykes and the possible tectonic control on their emplacement.
Hydrology and -chemistry of a tidal basin (Königshafen, North Sea): A water isotope perspective
Authors: Böttcher Michael E. , Jenner Anna-Kathrina , Nantke Carla , von Ahn Cátia Milene E. , Schmiedinger Iris , Schell Antonia , Patricia Roeser , Riedel Ramona , Janßen Sebastian , Gilfedder Benjamin S. , Moosdorf Nils
Published: March 2022

The role that of fresh surface and ground water sources play on the coastal water balance, element balances, and the associated biogeochemical processes is currently a matter of intense debate and investigation. The measures of fresh and saline water mixing in coastal areas have been found to be challenging, however stable water isotopes (O-16, O-17, O-18), in combination with further hydrochemical tracers, provide a valuable tool to identify different sources, that are furthermore linked to different biogeochemical processes, e.g. impacting the benthic and pelagic carbon cycle.

In the present communication, we report on combined investigations in pore and surface waters of Königshafen Bay (North Frisian island Sylt, Germany), a tidal area in the eastern North Sea. In addition, tidal cycles at the outlet of the bay were sampled. Results are compared to potential surface and subterrestrial fresh water endmembers, open North Sea, submarine groundwater discharge in the backbarrier tidal area of Spiekeroog, as well as the Elbe river estuary. Besides dissolved major and minor elements, the stable water isotope composition is used to characterize the temporal and spatial distribution of different water sources to the bay and the seasonal dynamics in the water column. Porewater gradients indicate different degrees of freshening, locally already in the top 50 cm below the seafloor with spatial heterogeneity. Different fresh water endmembers are indicated both by the water isotope and hydrochemical signatures. It turns that at least two fresh water sources can be identified for sediments under SGD impact, that differ in composition from surface water sources draining into the southern North Sea. Further work is on the way to investigate the dynamics in the (sub)surface fresh water sources for the tidal basin and the link to other geochemical tracers, as well as the coupling to the dissolved carbon system on different temporal and spatial scales.

  

The investigations are supported by the DFG-project KiSNet, the BMBF project COOLSTYLE (CARBOSTORE), the DAAD, the DFG project Baltic Transcoast, and Leibniz IOW.
Verification of TRANsport Simulation Environment coupling with PHREEQC for reactive transport modelling
Authors: Steding Svenja , Kühn Michael , Kempka Thomas
Published: March 2022

Many types of geological subsurface utilisation are associated with fluid and heat flow as well as simultaneously occurring chemical reactions. For that reason, reactive transport models are required to understand and reproduce the governing processes. In this regard, reactive transport codes must be highly flexible to cover a wide range of applications, while being applicable by users without extensive programming skills at the same time. In this context, the TRANsport Simulation Environment (Kempka, 2020) was coupled with the geochemical reaction module PHREEQC (Parkhurst & Appelo, 2013), providing multiple features that make it applicable to complex reactive transport problems in various fields. Code readability is ensured by the applied high-level programming language Python which is relatively easy to learn compared to low-level programming languages. In the present study, common geochemical benchmarks are used to verify the numerical code implementation.

Currently, the coupled simulator can be used to investigate 3D single-phase fluid and heat flow as well as multicomponent solute transport in porous media. In addition to that, a wide range of equilibrium and nonequilibrium reactions can be considered. Chemical feedback on fluid flow is provided by adapting porosity and permeability of the porous media as well as fluid properties. Thereby, users are in full control of the underlying functions and equations of state. Both, the solution of the system of the partial differential equations and PHREEQC module, can be easily parallelised to increase computational efficiency.

The benchmarks used in the present study include density-driven flow as well as advective and diffusive reactive transport of solutes. Furthermore, porosity, permeability and diffusivity changes caused by kinetically controlled dissolution-precipitation reactions are considered to verify the main features of our reactive transport code. In future, the code implementation may be used to quantify processes encountered in different types of subsurface utilisation, such as geothermal energy production, geological energy, CO2 and nuclear waste storage.

References:

Kempka, T. (2020). Verification of a Python-based TRANsport Simulation Environment for density-driven fluid flow and coupled transport of heat and chemical species. Adv. Geosci. 54, 67–77. (https://doi.org/10.5194/adgeo-54-67-2020)

Parkhurst, D.L.; Appelo, C.A.J. (2013). Description of Input and Examples for PHREEQC Version 3 - a Computer Program for Speciation, Batch-reaction, One-dimensional Transport, and Inverse Geochemical Calculations. In Techniques and Methods; Publisher: U.S. Geological Survey; Book 6, 497 pp. (https://pubs.usgs.gov/tm/06/a43/)
What can the last century teach us about climate models?
Authors: Düsterhus André , Borchert Leonard , Mayer Björn , Koul Vimal , Pohlmann Holger , Brune Sebastian , Baehr Johanna
Published: March 2022

Climate models are an important tool in our understanding of the climate system. Among other things, we use them together with initialisation procedures to predict the climate from a few weeks to more than a decade. While the community has demonstrated prediction skill for various climate modes on these time scales in the past years, we have also encountered problems. One is the non-stationarity of prediction skill over the past century in seasonal and decadal predictions. It was shown in multiple prediction systems and for multiple variables that prediction skill varies over time. Potential reasons for this non-stationarity was found in the changing state of the North Atlantic system on multi-decadal scales and the limited representation of physical processes within the model. While on the one side this feature of climate predictions leaves uncertainties for future predictions it also highlights windows of opportunity and challenges within climate models. 

We investigate the past century for this non-stationarity with a special focus on the North Atlantic Oscillation, and how the North Atlantic sector changes during these low prediction skill periods. We will demonstrate the limited predictability of features of the North Atlantic Oscillation, like the movement of its activity centres, as well as its implication for the Signal-to-Noise paradox. We also discuss the implications of non-stationarity model prediction skill for the development on future prediction systems and which processes are most likely the reason for the current challenges the community faces.
Quantifying the impact of bathymetry changes on flood  events for the Trois-Lacs Basin
Authors: Redondo Sergio , Boucher Marie-Amélie , Lacey Jay , Parent Jérémy
Published: March 2022

Floods are a major threat to the security of populations worldwide. Their impact is dependent on the flood extension and water levels,  topographic factors, and many other variables. Meteorological factors such as precipitation, snow melt and base flow also influence the magnitude of flood events. Factors like river morphology, slopes, presence of flood plains, vegetation and soil types determine the response of the river or lake to meteorological conditions and hydrological events. Meteorological factors tend to be cyclical while topography is generally considered to remain constant over extended periods of time. However, river bathymetry is subject to changes over time due to sediment transport. For example, sediment re-positioning and accumulation can modify the bathymetry of water bodies.  Furthermore, lakes or reservoirs receive and accumulate sediments transported from upstream which could influence flood levels. In this study we use a two-dimensional hydraulic model (Telemac2D) to simulate different flood scenarios coupled with several different bathymetries of Trois-Lacs Lake in the province of Quebec, Canada. Four bathymetries were obtained between November 2020 and August 2021 and 3 historical bathymetries were also provided (yrs, 1974, 2004, and 2019).  To compare the bathymetries, total ‘available water volume’ is calculated, taking a common and constant reference water surface elevation. Streamflows entering the lake system were estimated using Hydrotel, a physics-based semi distributed hydrological model. These streamflows are used to calibrate the two-dimensional hydraulic model with measured water levels.  The project may help to establish a direct relation between sediment shifting and deposition and water distribution for extreme flood events, while also allowing the local community to improve measures for civil security and land-use planning at a regional scale.
Characterizing induced seismic events in the Groningen gas field using an efficient Hamiltonian Monte Carlo sampler: a case study
Authors: Masfara La Ode Marzujriban , Weemstra Cornelis , Cullison Thomas
Published: March 2022

In May 2019, an earthquake with a magnitude of 3.4 (local magnitude) hit the area of the Westerwijtwerd village in the province of Groningen, the Netherlands. The event is the result of the gas extraction in the Groningen gas field and is one of the largest events to date. To better understand the source characteristics of the event, we apply a probabilistic full-waveform inversion technique that we recently developed to the event's recordings. Specifically, we use a variant of the Hamiltonian Monte Carlo (HMC) algorithm. When sampling high-dimensional model spaces, HMC is proven to be more efficient than the generic Metropolis-Hasting algorithm. Compared to probabilistic inversions of tectonic events, two main challenges arise while applying the algorithm. First, the prior information of the event is usually incomplete and inaccurate. That is, the only available information is (an estimate of) the hypocenter and origin time. Second, the frequency content of the induced event's seismograms is higher than that of typical tectonic events. This implies a higher non-linearity, which in turn complicates the ability of a probabilistic inversion algorithm to sample the model spaces, particularly when considering the first challenge. Consequently, to address both challenges, first, we develop a procedure to estimate the necessary prior information and use it as input to the HMC variant. Second, we run our HMC algorithm iteratively to mitigate the non-linearity. Using the relatively detailed velocity model of the Groningen gas field, we eventually estimate ten posteriors of the source parameters. The latter being the hypocenter (three parameters), the moment tensor (six independent parameters), and the origin time.  
Life-span economic and environmental analysis of deep borehole heat exchanger coupled geothermal heat pump heating system with different drilling depths
Authors: Cai Wanlong , Wang Fenghao , Chen Chaofan , Wang Zeyuan , Jiang Jinghua , Kolditz Olaf , Shao Haibing
Published: March 2022

Geothermal energy stored in the 1~2 km depth, which has advantages in terms of its continuity and sustainability, has attracted more attention in recent decades in the building heating industry. To meet the carbon-neutral prospect in the building sector, a new-type deep borehole heat exchanger (DBHE) is proposed to extract geothermal energy and has been utilized in Europe and northern China. The DBHE is typically drilled to more than 2000 m depth, and it is usually coupled with a heat pump to supply heat to the buildings. In this work, a dual-continuum finite element method was implemented in the open-source software OpenGeoSys to mimic the heat transfer process between the DBHE and the surrounding subsurface. After validating against in-situ experimental data of the pilot DBHE heating project in Xi’an, a heat pump model was also included in the OpenGeoSys model so that the entire heating system can be simulated over the long-term operation. Results show that the circulation temperatures of the DBHE have a decreasing trend during the long-term operation. Through the energy analysis, the amount of heat extracted by the DBHE was found to be mainly supplied by the energy stored within the surrounding soil. With different drilling depths of the DBHE, long-term simulation results illustrate that the heat extraction rate increases with deeper depth. After considering the electricity consumption of the heat pump and circulation pump, the Levelized cost of heating (LCOH) of the DBHE heating system was evaluated over its life-span cycle, and the optimal drilling depth of the DBHE was found to be 2600 m based on the specific geological properties of Weihe Basin, Xi’an. The proposing evaluation method provides a reference for decision-makers when designing the DBHE heating system.
Learning from the Science for Humanitarian Emergencies and Resilience (SHEAR) programme: challenges, innovations and research outcomes on forecasting and early warning
Authors: Brown Sarah , Budimir Mirianna , Sneddon Alison
Published: March 2022

The Science for Humanitarian Emergencies and Resilience (SHEAR) programme is an interdisciplinary, international research programme jointly funded for five years by the UK's Foreign, Commonwealth & Development Office (FCDO) and the Natural Environmental Research Council (NERC). It aims to support improved disaster resilience and humanitarian response by advancing monitoring, assessment and prediction of natural hazards and risks across sub-Saharan Africa and South Asia. SHEAR projects have been working with stakeholders to co-produce demand-led, people-centred science and solutions to improve risk assessment, preparedness, early action and resilience to natural hazards.

This session will share recently published challenges, learning and research outcomes from the SHEAR programme related to operational forecasting and early warning on: i) improvements in forecasting science, data, tools and decision making; ii) putting stakeholder needs at the centre; iii) interdisciplinary collaboration; iv) and lessons for future funding.

SHEAR projects have worked to advance the quality of the forecast information to support preparedness, by increasing the confidence, credibility and usability of forecasting science. The session will share advances made in developing new or improved forecast products for various natural hazards and their impacts in Asia and Africa.

SHEAR has also been working towards improvements in data; data plays a key role in preparing for and responding to disaster risks. With improved quality, availability, and accessibility of hazard-related data, disaster impacts can be better defined and anticipated.

The SHEAR projects have generated new knowledge through the development and use of new co-designed tools to support forecasting, early warning, and early action. The strong focus on participatory methods improved the effectiveness, the sustainability and the (policy) commitments to address risks and strengthen resilience in some of the most hazard-prone parts of the world. The co-designed, practical tools applied in SHEAR has enabled effective, appropriate and accessible transformation of knowledge into action.

The action people take based on forecasts is not always sufficient. SHEAR has worked with stakeholders at all levels and across sectors to improve anticipatory capacities and decision-making processes to enhance action in the face of future hazards. The session will show learning and examples from SHEAR demonstrating the requirement for a dedicated processes to support stakeholders in vulnerable areas to access, understand and subsequently plan for action that can strengthen their resilience in the face of potential upcoming disasters.
Magmatic processes at rifted margins: Preliminary results from peridotites of the Diamantina zone (SW Australia)
Authors: Ballay Mélanie , Ulrich Marc , Manatschal Gianreto
Published: March 2022

Keywords: magma-poor rifted margin, refertilization, partial melting, mantle-melt interaction

Although magmatic processes are of primary importance for the understanding of lithospheric breakup, many first order questions remain, such as: how, when, where and how much magma is produced during final rifting; what are the conditions and controlling processes of magma production; how does magma percolate and interact with the lithospheric mantle; and how and when does magma focus, how is it extracted and how does it interact with the extensional processes during final rifting and breakup? Answering to these questions is a prerequisite to understand lithospheric breakup and formation of a new plate boundary, which is among the least understood plate tectonic processes at present.

In this study we present preliminary petrological results from mantle rocks dredged from the SW Australia ocean-continent transition (OCT, Diamantina zone). We analyzed pyroxene and spinel compositions from these peridotites to identify mantle domains and mantle-melt reactions during rifting and breakup. The chemical composition of clinopyroxenes shows two distinct populations: a first generation characterized by low (Sm/Yb)N ratios and no Eu anomalies, while a second generation shows interstitial textures and flat HREE patterns with a deep negative Eu anomaly. These two populations of clinopyroxenes suggest that the peridotites from the Diamantina zone record two distinct events: a first cooling event that is followed by magma infiltration. This is further supported by equilibrium temperatures calculated on the two clinopyroxene generations showing that the first population equilibrated at lower temperatures (900°C ± 30°C) corresponding to a subcontinental geotherm, while the second generation equilibrated at higher temperatures (1100°C ± 100°C), and was likely liked to the entrapment of MORB-type melts in the plagioclase stability field at low pressure (~5kbar) during magma infiltration.  

The exhumation path of the Diamantina peridotites determined in our study is similar to those of refertilized peridotites from the present-day Iberia and fossil Alpine Tethys OCTs, suggesting that refertilisation processes occurring at magma-poor rifted margins during final rifting and breakup are not dependent from the inherited nature of the subcontinental mantle.
The use of multi-level and multi-scale spectral data approach to evaluate the vineyard status.
Authors: Ezzy Haitham , Brook Anna , Monaco Eugenia , Buonanno Maurizio , Albrizio Rossella , Giorio Pasquale , Erbaggio Arturo , Arena Carmen , Petracca Francesca , Cirillo Chiara , De Micco Veronica , Bonfante Antonello
Published: March 2022

Abstract

Currently, the main goal of agriculture is to promote the resilience of agricultural systems in a sustainable way through the improvement of use efficiency of farm resources, increasing crop yield and quality, under climate change conditions. This last is expected to drastically modify plant growth, with possible negative effects especially in arid and semi-arid regions of Europe on the viticultural sector. In this context, the monitoring of spatial behavior of grapevine during the growing season represents an opportunity to improve the plant management, winegrowers’ incomes, and to preserve the environmental health, but it has additional costs for the farmer. Nowadays UAS equipped with a VIS-NIR multispectral camera (blue, green, red, red-edge, and NIR) represents a good and relatively cheap solution to assess plant status spatial information (by means of a limited set of spectral vegetation indices), representing important support in precision agriculture management during the growing season. While differences between UAS-based multispectral imagery and point-based spectroscopy are well discussed in the literature, their impact on plant status estimation by vegetation indices is not completely investigated in depth. The aim of this study was to assess the performance level of UAS-based multispectral (5 bands across 450-800nm spectral region with a spatial resolution of 5cm) imagery, reconstructed high-resolution satellite (Sentinel-2A) multispectral imagery (13 bands across 400-2500 nm with a spatial resolution of <2 m) through Convolutional Neural Network (CNN) approach, and point-based field spectroscopy (collecting 600 wavelengths across 400-1000 nm spectral region with a surface footprint of 1-2 cm) in a plant status estimation application, and then, using Bayesian regularization artificial neural network for leaf chlorophyll content (LCC) and plant water status (LWP) prediction. The approach was realized within the Italian regional project GREASE, in an experimental vineyard of Greco of Feudi di San Gregorio winery (southern Italy), where detailed and precise records on soil and atmosphere systems, in-vivo plant monitoring of eco-physiological parameters have been conducted.

Keywords: precision agriculture, vineyard monitoring, spectral measurements, CNN applied to viticulture, UAS.
How much kinetic energy can the large-scale atmospheric circulation at best generate?
Authors: Kleidon Axel
Published: March 2022

I use thermodynamics and an Earth system approach to determine how much kinetic energy the atmosphere is physically capable of generating at large scales from the solar radiative forcing.  The work done to generate and maintain large-scale atmospheric motion can be seen as the consequence of an atmospheric heat engine, which is driven by the difference in solar radiative heating between the tropics and the poles.  The resulting motion transports heat, which depletes this differential solar heating and the associated, large-scale temperature difference, which drives this energy conversion in the first place.  This interaction between the thermodynamic driver (temperature difference) and the resulting dynamics (heat transport) is critical for determining the maximum power that can be generated.  It leads to a maximum in the global mean generation rate of kinetic energy of about 1.7 W m-2, which matches rates inferred from observations of about 2.1 - 2.5 W m-2 very well.  This represents less than 1% of the total absorbed solar radiation that is converted into kinetic energy. Although it would seem that the atmosphere is extremely inefficient in generating motion, thermodynamics shows that the atmosphere works as hard as it can to generate the energy contained in the winds.  I then show that this view of atmospheric dynamics is essentially the same as a maximised generation rate of Available Potential Energy (APE) for the Lorenz energy cycle, and that it is also consistent with the outcome of the proposed principle of Maximum Entropy Production (MEP) while representing a more physically interpretable approach.  This supports the notion that Earth system processes evolve to and operate near their thermodynamic limit, which permits the use of this constraint to do climate science analytically with less empirical input.
Two stage inversion method for microplastics emission estimation
Authors: Tichý Ondřej , Evangeliou Nikolaos , Šmídl Václav
Published: March 2022

The goal of this contribution is to explore two-stage inversion algorithm for spatio-temporal emission estimation (2D and time) from deposition measurements of microplastics and microfibers from Western USA. We consider the linear inversion model formulated as y = M x , where y is the measurement vector, M is source-receptor-sensitivity matrix computed using Lagrangian particle dispersion model FLEXPART, and x is the unknown emission vector from given spatial element. The inverse problem is typically ill-conditioned due to the measurements sparsity, hence, we propose two stage algorithm for inversion of this type. First, we run the inversion algorithm for the whole spatial domain, hence, we obtain averaged emission from each spatial element of the considered spatial domain. Second, we use the estimated emission from the first step (common for all spatial elements) as a prior emission in the second step where the inversion problem is considered for each spatial element separately. We demonstrate that this approach regularizes the inversion problem of spatio-temporal emission from sparse measurements, concretely on microplastics and microfibers emission estimation in Western USA.
Modeling the Greenland englacial stratigraphy
Authors: Born Andreas , Robinson Alexander , Theofilopoulos Alexios
Published: March 2022

Radar reflections from the interior of the Greenland ice sheet contain a comprehensive archive of past accumulation rates, ice dynamics, and basal melting. Combining these data with dynamic ice sheet models may greatly aid model calibration, improve past and future sea level estimates, and enable insights into past ice sheet dynamics that neither models nor data could achieve alone.

In this study, we present the first three-dimensional ice sheet model that explicitly simulates the Greenland englacial stratigraphy. Individual layers of accumulation are represented on a grid whose vertical axis is time so that they do not exchange mass with each other as the flow of ice deforms them. This isochronal advection scheme does not influence the ice dynamics and only requires modest input data from a host thermomechanical ice sheet model.

Using an ensemble of simulations, we show that direct comparison with the dated radiostratigraphy data yields notably more accurate results than calibrating simulations based on total ice thickness. We show that the isochronal scheme produces a more reliable simulation of the englacial age profile than Eulerian age tracers. Lastly, we outline how the isochronal model can be linearized as a foundation for inverse modeling and data assimilation.
Extreme cold events: global climatology and relation to cyclones 
Authors: Klaider Noy , Raveh-Rubin Shira
Published: March 2022

Extreme cold weather events cause major damage to industry, agriculture and human health. While regional extremes are often associated with different large-scale atmospheric circulation anomalies, it is yet unclear which mechanisms and weather systems are relevant on a global scale, i.e., across regions. This study aims to identify the large-scale processes leading to extreme cold events from a global climatological perspective, and specifically quantify the non-local contribution of midlatitude weather systems using a Lagrangian approach. 

Here, we objectively identify anomalously cold extremes by applying local percentile-based thresholds of 2-m temperature in ERA5 reanalysis. We further track air parcel trajectories of dry, cold intrusions occurring in the wake of extratropical troughs and cyclones, previously shown to induce cold anomalies following cold frontal passages. We find a strong association between cold extremes and dry intrusions, reaching 45% of cold extremes in the midlatitudes, despite the intrusions’ natural occurrence frequency of only 12% in those areas. Using clustering methods, additional atmospheric precursors to cyclones producing cold extremes are highlighted. The identification of mechanisms governing the predictability of cold extremes, on a global scale, is key for societal preparedness.  

 
3D geodynamic evolution of strike-slip restraining and releasing bends modulated by surface processes: application to the Dead Sea Transform
Authors: Heckenbach Esther , Brune Sascha , Glerum Anne , Neuharth Derek
Published: March 2022

The region around the Dead Sea Transform represents a unique example of the structures that form around restraining and releasing bends in a strike-slip environment. With our 3D numerical models, we aim to understand the processes that shaped the region including the Dead Sea Basin, the Dead Sea Transform Fault, and the Lebanese Restraining Bend.

In our study, we employ geodynamic modelling using the software ASPECT coupled to the surface processes code FastScape. Our model setup includes a compressive and a tensional stepover along a strike-slip fault with periodic along-strike boundary conditions. Even though we use a simplistic setup with horizontally homogeneous rock layers, we can reproduce many of the present-day features of the Dead Sea Transform region, including the sediment thicknesses in the Dead Sea basin, heat flow patterns, relative topographical height differences, and the general outlines and activity of the main faults along the Dead Sea basin, the Mount Lebanon and Anti Lebanon ranges.

With our models we can investigate the influence of surface processes on the underlying stepover strike-slip tectonics and the resulting crustal-scale flower structures: (1) Along the tensional stepover, the horizontal distance between the bounding faults of the pull-apart basin increases with greater efficiency of surface processes due to an increasing sediment load filling the basin. The sediments hinder the border faults in approaching each other at the surface, thereby enforcing basin-ward fault dip, resulting in wider and deeper basins with greater surface process efficiency. (2) In the uplifted compressive stepover, the erosional efficiency has a direct feedback on the longevity of faults and the rheological state of the crust through its influence on the uplift rate. Elevated erosion-induced uplift rates lead to a connection of the brittle parts of lower and upper crust, because the upper crustal viscous part is moved into a zone of lower temperatures and thus becomes brittle. This drastic change of the underlying rheology manifests in the formation of a new fault, which cuts through the centre of the compressional area. When no erosion is assumed a similar fault is observed in map view, but cross sections reveal that without erosion this fault has a different origin and the flower structure is more complex and more symmetric than for models that include erosion.
Simulation of pure qP-wave in vertical transversely isotropic media
Authors: Zhang Yi , De Siena Luca , Kaus Boris
Published: March 2022

Acoustic wave equations are widely employed in wavefield extrapolation and inversion due to their simplicity compared to the elastic wave equations. In anisotropic media, qP- and qSV-waves are coupled. Multiple acoustic approximations in the vertical transversely isotropic (VTI) media have been proposed during the last decades. A classic way is to set the vertical S-wave velocity zero. As such, the S-wave artefacts still exist, whose amplitude increases with anisotropy. Setting S-wave velocity zero in all propagating directions tackles the issue. However, the higher-order spatial derivatives in the pure qP-wave equation make it hard to solve in the space domain. The spatial derivatives in the denominator of the pure qP-wave equation make the solution by the spatial-domain finite-difference unstable.  In this study, we employed the time-domain pseudospectral method to solve both the classic acoustic wave equation and the pure qP-wave equation in VTI media. Hybrid absorbing boundary conditions are used. Both equations are applied to reverse time migration (RTM) for the anisotropic Marmousi model. The new qP-wave equation outperformed the classic qP-wave equation regarding the computational time. Further work can be extended to waveform inversion with the pure qP-wave equation.
Crustal growth of Archean and early Proterozoic granitoids of the Ivindo region in the Souanké and Bomalinga areas from Congo Craton (North-West Republic of Congo)
Authors: Loemba Rodeck Patrick Alan , Ntsiele Legran Juldit Espoir Plavy , Opo Urbain Fiacre , Bazebizonza Tchiguina Carmel , Nkodia Hardy Medry Dieu-Veill , Boudzoumou Florent
Published: March 2022

Most interpretations of the Archean rocks in the Central Congo Craton have only focused on data from Cameroon and Gabon, few of them have included data from the Ivindo region in northwest Republic of Congo. This study presents for the first time a regional interpretation of the Archean rocks of the Congo craton from data on granitoids of the Ivindo region. Modal compositions vary between quartz-rich granitoids or pegmatite, granodiorites, granites and tonalites. These rocks are metaluminous and peraluminous (~0.8≤A/CNK≤~1.3) and define magmatic lineages that are predominantly calc-alkaline, tholeiitic, and rarely highly potassic calc-alkaline. REE diagrams show that these rocks are rich in rare earth elements (LREE) and large ionic lithophile (LILE), while exhibiting significant negative anomalies in Nb-Ta, and in Ti. Such geochemical signatures indicate that these granitoids formed possibly in a subduction tectonic setting. These geochemical signatures are comparable with the Dharwar, North China, and Pilbara cratons, also in similar Archean cratons.

The U-Pb ages based on zircon indicate that tonalites were amplaced at (2891.2 ± 10.6 and 2820.37 ± 6.23 Ma), pegmatite were amplaced at (2878.2 ± 13.6 and 2891.0 ± 12.6 Ma), granodiorite were ampleced at (2828. 98 ± 6.23 Ma) and granite were ampleced at (2430.19 ± 8.11 Ma). Thesse periods of magmatisme describe here revels the magmatic history of the Archean granitoids of the Congo craton in the Ivindo Bassement from 3085 ± 21.6 and 2430.19 ± 8.11 Ma.

Keywords: Archean, Crustal growth, Granitoids, Ivindo region, Congo craton, Republic of Congo.

 

 
Investigating Potential Safe Landing Sites for ESA/ROSCOSMOS' Luna 27 Mission
Authors: Boazman Sarah , Heather David , Sefton-Nash Elliot , Orgel Csilla , Houdou Berengere , Lefort Xavier , Lunar Lander Team The
Published: March 2022

ESA and ROSCOSMOS’ Luna 27 mission will explore the south polar region of the Moon and will sample the lunar surface. To ensure the best samples are collected, which yield the greatest scientific return eight potential landing sites are being investigated using remote sensing methods. We have studied the safety of the eight potential landing sites by creating slope maps using the LOLA (30m/px) digital elevation model and classified slopes into safe areas (slopes <10°) and unsafe areas (slopes >10°). Additionally, we created slope maps classified in 2° intervals from 0-14° and greater than 14°, to further investigate which areas have the lowest slopes and therefore potentially the safest landing sites.

      We found that each of the eight landing sites contain areas that are safe for landing (slopes <10°) and sites 1, 2, 4, 6 and 8 contain large areas (>500 km2) that are classified as safe for landing. Site 3 has large craters with steep crater walls, which may present a hazard to landing. At site 5 there is a large crater (~20 km diameter) to the bottom right of the site, which has a steep crater walls and rim, which creates a topographic ridge in the south east of the landing site and should be avoided as a landing site. Site 7 also has a steep topographic ridge which again should be avoided as a landing area. In comparison site 8 contains a large area with shallow slopes in the center with slopes of 0-2°, which would be an ideal landing site. Site 1 covers a large crater (~40 km diameter), and the center of the crater floor has shallow slopes with less than 4°. Site 2 similarly has a large crater floor with slopes less than 4°. Both the crater floors of site 1 and site 2 could be a safe landing site.

     This initial investigation into the potential landing sites has identified areas which could be safe for landing Luna 27. Future work will use multiple datasets to explore the scientific potential of the landing sites including investigating the surface roughness, identifying craters and boulders, which could present a hazard to the lander, using thermal maps to measure the thermal stability, and exploring the illumination conditions and Earth visibility at each of the landing sites.
On differences in climate feedback evolution in abrupt4xCO2 climate model experiments
Authors: Eiselt Kai-Uwe , Graversen Rune
Published: March 2022

Climate sensitivity – the response of the Earth’s surface temperature to radiative forcing – and climate feedbacks are important and widely used metrics to gauge global climate change. In recent years it has become clear that climate sensitivity and feedback change over time in numerical climate model experiments but the reasons for this change are not yet well understood. We investigate the abrupt4xCO2 experiment as simulated by multiple members of the Coupled Model Intercomparison Project (CMIP) phases 5 and 6 and apply a radiative kernel method to decompose climate feedback into contributions from physical processes. We extract two groups of models, one with small (G1) and one with large (G2) global mean lapse-rate feedback change over time. It is found that the model groups differ with respect to warming and feedback patterns and that the Arctic stands out as the region with the biggest between-group differences. We retrace these Arctic changes to the different evolution of Arctic sea ice in both model groups. A further finding is that G1 members exhibit much more warming over the simulation period than G2s members. This appears to result from a more positive early cloud feedback in G1 than in G2. Further investigation is needed to uncover possible cause-effect relationships between Arctic changes and global feedbacks.