bluuebunny/crossref_metadata_2025 huggingface dataset:
Integration of ground-based radar interferometry (GB-InSAR) and weather forecasts for real-time monitoring: kinematic evolution and early warning of the Sant’Andrea landslide (Eastern Italian Alps)
Authors: Catani Filippo , Carraro Edoardo , Galgaro Antonio
Published: March 2022

Early warning for complex landslides is a difficult task since their evolution could depend on the combination of various predisposing and triggering geological (e.g. rock type, water circulation) and climatic factors (e.g. rainfall, snowmelt). Depending on the type of phenomenon, the temporal evolution of a landslide can be monitored in several ways, from classical to recent advances in remote sensing and in-situ measurements. The potential of real-time monitoring by ground-based radar interferometry (GB-InSAR) is exploited here to improve the understanding of the kinematic evolution of a complex landslide in the Italian Alps. To this end, the integrated use of long-term, spatially distributed GB-InSAR data and of a classical Robotic Total Station (RTS) monitoring is analyzed and discussed for the Sant’Andrea landslide, located in the municipality of Perarolo di Cadore (Belluno, Italy), a rotational slide in heterogeneous materials. Due to the landslide features, the use of these two different techniques is complementary: GB-InSAR measures a continuous field of motion, although along LOS, that is suitable for detecting unstable sectors and quantifying the space-time variations of the kinematics on the entire slope, whereas RTS is able to acquire tridimensional displacement data, very useful to monitor single points and to correctly interpret the GB-InSAR data. The landslide position, just upstream of the village center, represents a relevant hydrogeological risk for the inhabitants. This complex mass movement involves a clay-calcareous debris mass overlying an anhydrite-gypsum dolomitic bedrock. The kinematic activity exhibits an alternation of slow displacements, as long-term creep, and episodic or seasonal accelerations, strongly related to rainfall triggering in response to both heavy and lasting events. Based on the intensity and duration of rainfall, the significant accelerations are followed by a relaxation period with a slow regression of the displacement rate, usually without returning to the previous values.
The analysis carried out by combining the mapping of 3D point-based displacements and LOS surface velocity fields allows distinguishing mechanisms and sensitivity of the landslide sectors to rainfall inputs, as well as to understand the wide range of mechanical behaviors shown by the slope during the monitoring period. Such information aims to quantitatively evaluate the trigger-response signals to rainfall events to predict accelerating trends of the landslide displacements as well as possible failures. The proposed monitoring and modelling framework will be soon implemented in an operational early warning procedure using real-time, high-frequency GB-InSAR data together with RTS and weather forecasts, in accordance with local authorities of Civil Protection.

 
Investigation of 3D Fracture Propagation in Complex Reservoirs Rocks at Microscale
Authors: Nachev Victor , Turuntaev Sergey
Published: March 2022

This work aims to study the propagation of fractures during hydraulic fracturing operations to determine the conditions that lead to the most extensive network of secondary fractures along with the main fractures at the microlevel. The occurrence and propagation of 3D fractures were studied, considering the granular composition and complex structure of elastic-plastic rock samples. The simulation allowed us to calculate fracture networks for various loading conditions. We propose a method that will enable us to calculate the pressure of hydraulic fracturing fluid injection into the formation from the obtained numerical conditions of loading and regional stress in the reservoir rock. Based on the results of numerical modeling and recalculation of the obtained loading conditions into the pressure of the injected fluid, geomechanical engineers will choose the necessary conditions that will provide the stress-strain states that lead to the most significant degree of fracturing of the formation.
Implementing semantic data management for bridging empirical and simulative approaches in marine biogeochemistry
Authors: Schlemmer Alexander , Merder Julian , Dittmar Thorsten , Feudel Ulrike , Blasius Bernd , Luther Stefan , Parlitz Ulrich , Freund Jan , Lennartz Sinikka  T.
Published: March 2022

CaosDB is a flexible semantic research data management system, released as open source software. Its versatile data model and data integration toolkit allows for applications in complex and very heterogeneous scientific workflows and different scientific domains. Successful implementations include biomedical physics [1] and glaciology [2]. Here, we present a recent implementation of a use case in marine biogeochemistry which has a special focus on bridging between experimental work and numerical ocean modelling. CaosDB is used to store, index and link data during different stages of research on the marine carbon cycle: Data from experiments and field campaigns is integrated and mapped onto semantic data structures. This data is then linked to data from numerical ocean simulations. The ocean model, here with a specific focus on natural marine carbon sequestration of dissolved organic carbon (DOC), uses the georeferenced data to evaluate model performance. By simultaneously linking empirical data and the sampled model parameter space together with the model output, CaosDB enhances the efficiency of model development. In the current implementation simulated data is linked to georeferenced DOC concentration data. We plan to expand it to complex data sets including thousands of dissolved organic matter molecular formulae and metagenomes of pelagic microbial communities. The combined management of these heterogeneous data structures with semantic models allows us to perform complex searches and seamlessly connect to automated data analysis pipelines.

[1] Fitschen, T.; Schlemmer, A.; Hornung, D.; tom Wörden, H.; Parlitz, U.; Luther, S. CaosDB—Research Data Management for Complex, Changing, and Automated Research Workflows. Data 2019, 4, 83. https://doi.org/10.3390/data4020083
[2] Schlemmer, A.; tom Wörden, H.; Freitag, J.; Fitschen, T.; Kerch, J.; Schlomann, Y.; ... & Luther, S. Evaluation of the semantic research data management system CaosDB in glaciology. deRSE 2019. https://doi.org/10.5446/42478
Using UAV and geostatistics to upscale crop yield in heterogeneous agro-silvo-pastoral system
Authors: Agbohessou Yélognissè , Audebert Alain , Ndour Adama , Sarr Mame Sokhna , Jourdan Christophe , Clermont-Dauphin Cathy , Diatta Sékouna , Leroux Louise , Taugourdeau Simon , Sanogo Diaminatou , Seghieri Josiane , Delon Claire , Roupsard Olivier
Published: March 2022

The beneficial effect of Faidherbia albida on the yield of certain associated crops has been demonstrated for long and is often characterized by a distance-decay pattern. While several approaches have tested the spatial extent assessment of tree influence, none of them has been designed either to capture the directional variations or to address the park effect at the landscape scale. Recently, Roupsard et al. (2020) proposed an approach based on multispectral (MS) UAV (Unmanned Aerial Vehicle) imagery and geostatistics to bridge this gap. In the present study, we extended their study by proposing a new application of their approach to groundnut crop and validation for millet crop. In addition, we tested improvements of the method, using several MS images along the crop cycle.

In a typical F. albida parkland (Niakhar, Senegal), groundnut and millet under-crops of agroforestry plots of approximately 1-ha and 2-ha respectively, have been harvested. On each plot, groundnut and millet traits were measured at three different positions from six F. albida trees (under crown "S"; crown edge "B" and far from the crown "H"). We found that F. albida improves the haulm yield of the groundnut crops under its crown by about 50%. However, unlike its strong effect on millet, it does not significantly affect the groundnut pod yield. Through geostatistical analysis of multi-spectral, centimetric-resolution images obtained from the UAV flights carried out during the wet season, we observed that F. albida affects the groundnut NDVI signal up to 9.8-m and the NDVI of millet up to 18-m. We found statistically significant, positive correlations between groundnut pod yield and MSAVI2, NDVI (r2 = 0.73; RMSE = 9.8) first, and between groundnut haulm yield and MSAVI2 (r2 = 0.85; RMSE = 5.81). For millet, the multiple linear regression model is able to explain 74% of the millet yield variability (RMSE=20.48) using millet+weed MSAVI2 and NDVI. We used the regression model to upscale groundnut pod and haulm yield maps at the whole-plot scale. Compared with groundtruth, the error was only by 8% and 13% for groundnut pod and haulm yield, respectively. Using a geostatistical proxy for the sole crop, the crop-partial Land Equivalent Ratio (LERcp) was estimated at 1.02 for pod yield and 1.05 for haulm yield.
Influence of Different Atmospheric Aerosol Compositions on the Life Cycle of Stratiform Clouds over Southern West Africa
Authors: Delbeke Lambert , Wang Chien
Published: March 2022

Low-Level Stratiform Clouds (LLSC) appear frequently over southern West Africa (SWA). During the West African Monsoon (WAM) period, both local (air pollution) and remote (dust and biomass burning aerosols from North and Central Africa, respectively) aerosol sources can play a significant role in LLSC diurnal life cycle. The Dynamics-Aerosols-Chemistry-Cloud Interactions In West Africa (DACCIWA) campaign has produced a considerable number of clouds and aerosols measurements during the WAM in 2016. Numerical simulations using a Large Eddy Simulations (LES) model with detailed aerosol and cloud microphysical processes and constrained by DACCIWA observations have been conducted, driven by different atmospheric aerosol compositions in order to study the impacts of different aerosols on the key processes (formation, break-up, transition to cumulus) of LLSC. Detailed results alongside conclusions will be presented.
The Norian magmatic rocks of Jabuka, Brusnik and Vis Islands (Croatia) and their bearing on the evolution of Triassic magmatism in the Adria Plate
Authors: Velicogna Matteo , Prasek Marko Kudurna , Ziberna Luca , De Min Angelo , Brombin Valentina , Jourdan Fred , Renne Paul R. , Marzoli Andrea
Published: March 2022

The magmatic bodies of Jabuka, Brusnik, and Vis Islands of the Adriatic Sea are located in the easternmost part of the Adria Plate (Adriatic Unit according to Slovenec & Šegvić, 2021), close to the External Dinarides (Pamić and Balen, 2005). The magmatic rocks on the islands are, from West to East, intrusive bodies on Jabuka, sub-intrusive on Brusnik, and effusive rocks on Vis.

Feldspar separates from Jabuka and Brusnik Islands yielded mini-plateau 40Ar/39Ar ages of 229.0 ± 5.4 Ma and 221.5 ± 2.5 Ma indicating that this magmatism is Carnian-Norian in age. The whole-rock geochemical compositions (major and trace elements, Sr-Nd isotopes) indicate that the magmatic rocks of the Croatian Islands range from tholeiitic to calc-alkaline, yielding a subduction signature. This signature is also shared by coeval magmas from the Adria Plate and may be related to crustal components subducted during the Hercynian orogeny and recycled within the mantle source(s) of this anorogenic magmatism.
Unfolding the ecological and water quality Implications of Inter Basin Water Transfers Using a SourceTracking Modeling Framework
Authors: Molakala Manvitha , Singh Riddhi
Published: March 2022

Reservoir water balance models are often used in system models that translate state variables to measurable goals in water management studies. These models enable water managers to analyze the impact of various operational strategies on the performance of water resource systems. However, the water quality implications of reservoir operations are relatively less explored as it entails additional processes in the model, requiring data and parameterization. Water quality implications are particularly important in projects such as inter-basin water transfers (IBWTs), in which water is diverted from one basin to other in the presence of considerable regional differences in water supply and demands between two basins. When water from one basin is transferred to another, the difference in water quality can affect the local flora and fauna of the recipient basin. So, it is important to understand the relative proportion of water from either basins present in the recipient reservoir at any time. Here, we propose a source tracking framework to quantify the contribution of water from either basins to various reservoir-related fluxes in the recipient basin. These include water released from the recipient basin for: demand satisfaction, maintaining minimum environmental flows, preventing dam failure, and demands in basins. We quantify the proportion of water supplied from the donor basin and from the recipient's own inflows for each flux. We apply this framework to a proposed water transfer project in southern India that transfers water from the Godavari basin to the Krishna river basin. Our results show that under extreme droughts observed in the simulated inflows, up to 50% of the minimum environmental flows released downstream of the recipient reservoir are supplied from the water transferred from the donor basin. This generally occurs in the months from June to December in which the recipient experiences high demands. We also note that more than 50% of the water transferred out of the recipient reservoir to other basins arrives from the donor basin. Our framework can be used to evaluate the possible implications of water quality in the donor basin on the minimum environmental flows and other reservoir-related fluxes from the recipient reservoir. 
Using Synthetic Aperture Radar Images to Monitor Sand Dredgers in Taiwan Strait
Authors: Tsai Tsung Ying , Tseng Kuo Hsin
Published: March 2022

        With the unique geological setting, Taiwan Strait was formed by shallow bathymetry and gentle topography composed of sandy substrate types. The depth of this area seldom exceeds 100 m, and it could be shallower than 20 m in the Taiwan Shoal area. Therefore, in recent years, there have been frequent cases of illegal sand dredgers around the central of Taiwan Strait. Apart from destroying marine ecology, the greatest problem of illegal sand pumping is the consequential retreat of the neighboring coastline.

        To address this problem, the objective of this research aims to take advantage of Synthetic Aperture Radar (SAR) technology in satellite remote sensing, and to monitor the spatiotemporal hotspots of unidentified vessels. SAR instruments have the advantages of superior penetration, high resolution, and independent from sunlight, making it a great tool for ocean object detection. This research uses Sentinel-1 SAR imagery as data source. We take Taiwan strait as study area and focused on Taiwan Shoal and the offshore of Matsu islands, which are the regions with higher number of cases of illegal sand dredging in recent years. The workflow is composed of four steps: image preprocessing, land masking, prescreening, and ship discrimination. Our preliminary results show that the developed algorithm can automatically detect targets over a specific size (>30 m), with an accuracy of >80% compared with the manually identified results. The hotspot of sand dredgers is changing in locations in the last three years, with the peak number occurred in 2019. It is concluded that Sentinel-1 SAR image has the ability to serve as a tool for ship detection.
Evaluating the use of Petrography, zircon U–Pb ages and Sr–Nd isotopes in tracking provenance: A case study from Tsangpo-Siang-Brahmaputra Basin
Authors: Panda Sandeep , Kumar Anil , Singhal Saurabh , Srivastava Pradeep , Sagwal Sumit
Published: March 2022

The occurrence of catastrophic events i.e. floods has proven to play a key role in the rapid sediment delivery from the source area to depocenters and in understanding the focused erosion zones in highland areas. Tracking the provenance of these catastrophic flood sediments provides an insight into the linkage between climate-tectonic coupling and earth surface processes. In general, information on sediment sources has been derived through petrographic and mineralogical investigations on distinct grain-sized sediment or on a grain-by-grain basis, zircon U–Pb geochronology. However, information from fractionated sediment investigations has made it impossible to distinguish source areas using different methods. Sr-Nd isotopes on bulk sediment on the other hand, are still uncommon in tracing the sediment provenance. All three methods discuss the provenance based on the geology of the catchment area, cycles of erosion, mineral maturity. The petrographic and mineralogical investigations respond to short-term sedimentary processes, U-Pb zircon chronology responds to long-term sedimentary processes, however, Sr-Nd responds to both the processes. Therefore, it is crucial to critically examine all these methodologies in tracking the origin of sediment. This research gives an integrated mineralogical–geochemical database on sediments carried by the extreme events in the Tsangpo-Siang-Brahmaputra river system. We attempted to compare the above-mentioned fingerprint approaches and determine the optimal strategy by comparing them on the same samples to determine the relative relevance of various sources. The petrographic analysis was done using Gazzi-Dickinsion method and implied that most of the samples were eroded from Higher Himalaya with a minute amount sourced from Tibet Plateau. This was a bit mystifying as the floods were sourced by the bleaching of glacial dammed lakes from the Tibetan Plateau (Panda et al., 2020). In normal conditions, some studies using the zircon U–Pb geochronology have also suggested Higher Himalaya (Namche Barwa massif) as an erosional hotspot in North-Eastern Syntaxis but in case of extreme events, such study are yet to be done. While the Sr-Nd analysis was done and shows the dominancy of sediments derived from the Tibetan Plateau. Thus, the provenance fingerprinting using the two proxies gives dissimilar results. However, the robustness of Sr-Nd systematics allows us to suggest that the megafloods in the Siang River carried a large amount of sediments that were eroded from Tethyan sequences before entering into the George area, adding additional sediment from crystalline material of the higher Himalaya.

Keywords- Paleofloods, Provenance fingerprinting, sediment petrography, U–Pb zircon chronology, Sr-Nd isotopes.
Uneven preservation of ancient DNA along lake sediment cores: A case study of high-latitude and high-elevation lakes
Authors: Jia Weihan , Cabuk Ugur , R. Stoof-Leichsenring Kathleen , G. Alsos Inger , Lammers Youri , K. Biskaborn Boris , Herzschuh Ulrike
Published: March 2022

Although sedimentary ancient DNA (sedaDNA) is increasingly used to reconstruct past ecosystem changes, we do not yet know much about its preservation conditions across geological time, resulting in potential biases and uncertainties in data interpretation. In this study, we obtained sedaDNA records from around 15 lakes from the Arctic and sub-Arctic regions and the Tibetan Plateau covering the last 2 to 80 ka BP. In addition to the four preservation proxies recently introduced by Jia et al. (2021) (https://doi.org/10.1002/edn3.259), some new potential proxies of plant DNA metabarcoding (e.g., dissimilarity between PCR replicates) and metagenomics (e.g., average DNA fragment length, duplication rate, guanine-cytosine content, and deamination rate) have also been applied to quantify the extent of ancient DNA preservation and compared with other environmental proxy records from the cores. So far, our preliminary results from Lake Ilirney (67°21’N, 168°19’E) show that DNA content generally decreases along the core over the last 18 ka BP and then maintains at a relatively stable level up to the bottom of the core (ca. 53.4 ka BP), which is consistent with the variations in lake organic productivity reflected by TC, TOC, TOC/TN, pollen and diatom abundance, and Br. In addition, sedaDNA preservation conditions revealed by our preservation proxies are variable within the core. Good sedaDNA preservation is associated with strong physical weathering and glacial abrasion in the catchment, as indicated by high K/Ti and low Zr/Rb values, resulting in increased clastic input of clay minerals and fine sediments, which favors the adsorption of DNA molecules to sediment particles. This process might also help to deepen the lake and increase its water conductivity, which is beneficial for DNA adsorption and preservation. No clear correlation is found between sedaDNA preservation and paleoclimatic changes reconstructed by fossil pollen records. It should be noted that our results may also be influenced by the ability of the DNA extraction protocols we used to recover DNA from different types of sediments. To conclude, sedaDNA preservation may be highly influenced by sediment type and catchment erosion rate, and glacial lakes appear to be promising for sedaDNA studies in the future. Further analyses of sedaDNA records from other lakes are pending and will be finalized and presented at EGU 2022.
Modern hotspot-influenced MORBs reveal anoxic conditions during deposition and subduction of recycled Proterozoic sediments in their source
Authors: Ahmad Qasid , Wille Martin , Rosca Carolina , Labidi Jabrane , Schmid Timothy , Mezger Klaus , König Stephan
Published: March 2022

Significant Mo mobility and isotope (δ98/95Mo) fractionation is induced during prograde metamorphism at present-day subduction zones. Depending on the redox conditions during early subduction and accompanied slab dehydration, isotopically heavy Mo is released towards the overlying mantle wedge, leaving behind a depleted, and isotopically light subducted slab. This isotopically light Mo signature has been detected in slab-melt influenced volcanic rocks and potentially will be traceable in ocean-island basalts, if their geochemical signatures are affected by previously subducted lithologies (i.e. slab and overlying sediments). Thus, the isotope composition of mantle plume-influenced volcanic rocks might reveal the nature of subducted and re-incorporated lithologies and possibly redox conditions during subduction.

In this study, we present new Mo isotope data for South-Mid Atlantic Ridge basalts that partly interacted with the enriched Discovery and Shona mantle plumes. Isotopically heavier Mo isotope ratios (δ98/95Mo > ambient depleted mantle) are observed in samples tapping a more enriched mantle source. Furthermore, δ98/95Mo correlates with radiogenic isotopes (Sr, Nd, Hf) indicating recycling of a Proterozoic sedimentary components with a Mo isotopic composition that was not modified during and before subduction by Mo mobility under oxidising conditions. Rather, the new Mo isotope data supports and expands on previous stable Se and S isotope evidence that suggests the incorporation of subducted anoxic Proterozoic deep-sea sediments into the mantle of the South-Mid Atlantic Ridge basalts.
Discovery and characterization of environmental hazards by means of dynamic coordination of drones driven by satellite detection maps
Authors: Cicala Luca , Amitrano Donato , Cesario Vincenzo Angelino , Gargiulo Francesco , Gigante Gabriella , Nebula Francesco , Palumbo Roberto , Parrilli Sara , Pascarella Domenico , Tufano Francesco
Published: March 2022

In some environmental applications, satellite acquisitions could not be able to provide all the information necessary to characterize the problem at hand due, for example, to limited spatial resolution or inadequate revisit time. However, in these cases, they can be used for preliminary investigation of the area of interest with the purpose to guide subsequent acquisitions with higher spatial resolution made by means of aerial sensing. This work presents an innovative application combining both satellite acquisitions and aerial close-range sensing implemented via drones in autonomous and coordinated flight. The case study concerns the discovery of illegal micro-dumps and other environmental hazards in Campania Region (Italy). The envisioned workflow includes the detection of target environmental criticalities in very high-resolution optical satellite images and a methodology to plan and adaptively re-plan a survey mission of a team of drones aimed at confirming the presence of a micro-dump and at its characterization. The processing of satellite images is validated on real data in a significative application context, while the performance of the acquisition strategy performed by the drone team are characterized trough simulations on a pre-analysed geographical area.
Integrating methods to discriminate the soil historical pollution sources and assess the degree of contamination and related health risks in an urban environment:  the Commune of Santiago (Chile) case study.
Authors: Albanese Stefano , Aruta Antonio , Daniele Linda , Cannatelli Claudia , Buscher Jamie T. , De Vivo Benedetto , Petrik Attila , Cicchella Domenico , Lima Annamaria
Published: March 2022

The Commune of Santiago is an administrative unit belonging to Chile's capital city. It is the central hub for local transportation services and the centre of most national government functions. In 2017, a geochemical survey was carried out focusing on the topsoils of the commune. A total of 121 samples were homogeneously collected across an area of 22.4 sqkm to determine the spatial distribution of potentially toxic elements (PTE) and discover their primary and secondary sources. In the aim of the work, the assessment of human health risk for the local population was also included considering both the direct contact with soils and the breathing of airborne particles as relevant exposure pathways.
The geochemical baseline maps of 15 PTEs were generated using the Multifractal IDW (MIDW) interpolation, and map intervals were determined using a Concentration-Area plot considering the fractal structure of the geochemical data.
The contamination degree of the urban soil and its pattern was also calculated and mapped after developing a new index, named as Cumulative Contamination Degree (CCD), which integrate information about the severity of contamination and its spatial complexity.
A robust multivariate statistical analysis based on Principal Components (RPCA) was carried out considering the compositional nature of the geochemical data. In addition, to highlight the presence and the geochemical patterns depending on different contamination sources, a Sequential Binary Partition (SBP) was used to generate contrasts among those elements considered as proxies of specific processes (Urban traffic, productive settlements, etc.).
A probabilistic approach was chosen to assess the risk due to exposure to soils for the local population. It was based on Monte Carlo simulation to include uncertainty due to spatial variation of data and the relative mobility of people within the borders of the study area. 
The results obtained show that the innovation proposed to assess contamination and discriminate its sources, even when they are of secondary relevance, can generate positive feedback. Using a probabilistic approach in a non-site specific framework can even be considered a more reliable method to assess risks if we want to not underestimate the burden of uncertainty that substantially influences the results. 
Tropical ice clouds validation in Global Storm Resolving Models using active sensor retrievals
Authors: Bolot Maximilien , Fueglistaler Stephan , Harris Lucas , Cheng Kai-Yuan , Zhou Linjiong
Published: March 2022

Tropical ice clouds play an important role in the energy balance of the tropical atmosphere, yet their modeling has been a challenge and feedback from high clouds in climate models is very uncertain. The new generation of Global Storm Resolving Models (GSRM) is capable of resolving convective and mesoscale motions globally, and therefore promises to greatly advance our understanding of tropical clouds. This new generation of model also creates new opportunities for comparison with measurements since their horizontal resolution is comparable to that of active sensor measurements. Here we show the value of metrics evaluating cloud fraction, ice mixing ratio and longwave cloud radiative heating to validate tropical ice clouds simulated by Global Storm Resolving Models using A-Train ice cloud retrieval products. For this purpose, we use the X-SHiELD experimental Cloud Resolving Model, developed at NOAA/GFDL, and observations based on the 2C-ICE and DARDAR products, with the addition of the 2B-FLXHR-LIDAR radiative transfer algorithm for the validation of broadband fluxes. We show that, by aggregating model output and measurements in ice water path – pressure space, biases in the ice distribution can be revealed, whereby the position of the anvils is too low in the model. Such biases point to deficiencies in the microphysics of cloud ice, are likely shared by other models using similar microphysics packages, and have important consequences on thermal emission properties.
Critical assessment of pressure estimates in volcanic plumbing systems: the case study of Popocatépetl volcano, Mexico
Authors: Petrone Chiara Maria , Tommasini Simone , Bindi Luca , Lorenzo Savia , Mangler Martin M. , Orlando Andrea
Published: March 2022

Most geobarometers use chemical compositions of minerals and their host melt to estimate crystallization pressures. Crystal structural parameters such as cell and site volumes are not usually considered despite their known sensitivity to pressure. Here, we compare two clinopyroxene geobarometers based upon electron microprobe analysis alone and coupled with single-crystal X-ray diffraction data. The case study is the plumbing system of Popocatépetl volcano (Mexico), which consists of three distinct magma reservoirs in upper, middle and lower crustal depths, represented by three compositionally and texturally distinct clinopyroxene populations (T1, T2, and low-Ca). These clinopyroxenes are augites of limited compositional variability, although yielding a significant increase in cell (V cell) and M1 site (V M1) volumes from low-Ca and T2 core to T1 (core and rim) and T2 (rim) clinopyroxenes. This variation is not due to chemical or temperature effects but is linked to their depth of crystallization. The application of the geobarometer based on chemical composition alone is unable to distinguish the three different reservoirs postulated on volcanological and petrological grounds. In contrast, the application of the geobarometer based on both structural parameters and chemical composition yields a remarkable correlation between the calculated cell volume and the estimated depth of crystallization of the different clinopyroxenes, including core to rim differences.

These results have twofold implications. First, the determination of the structural parameters of clinopyroxenes is the only method to resolve the actual distribution of Mg, Fe2+, Fe3+ in the M1 and M2 structural sites and, given the sensitivity of cell and site volumes to pressure, permits to improve geobarometric estimates in volcanic plumbing systems. Second, the quantitative determination of the crystallization depth of the different clinopyroxenes has permitted to rescale the depth of the three different reservoirs in the plumbing system of the Popocatépetl Volcanic Complex located from ~30 km b.s.l. (low-Ca clinopyroxene) to ~18 km b.s.l. (T2 clinopyroxene core) and ~10-0 km b.s.l. (T1 clinopyroxene core and rim, T2 clinopyroxene rim) within the crustal structure of the Morelos platform. This provides further support to the complex plumbing system of the Popocatépetl Volcanic Complex consisting of polybaric storage layers of variable interconnected and interacting transient magma reservoirs.

From Tommasini et al. (2021), Lithos, https://doi.org/10.1016/j.lithos.2021.106540
Modeling changes in European beech productivity precipitated by spring late-frost
Authors: Meyer Benjamin F. , Buras Allan , Principe Adriana , Kreyling Jürgen , Rammig Anja , Zang Christian S.
Published: March 2022

Forest ecosystems are known to be paramount in maintaining the terrestrial carbon sink by storing nearly half of all terrestrial carbon, with European beech dominating these ecosystems across many parts of Europe. As such, the state of the carbon sink is mediated to a large degree by the productivity of European beech forests. Dynamic global vegetation models (DGVMs) can be useful tools to explore changes in forest productivity caused by climate extremes. However, DGVMs often lack implementation of processes pertaining to specific extremes, such as spring late-frost.
Though counterintuitive, temperature increases associated with climate change may exacerbate spring late-frost risk in European beech. Defoliation from late-frost can have detrimental effects on forest productivity. Affected trees lose the ability to effectively perform photosynthesis until the canopy is regrown and must also rely on the expenditure of stored carbohydrate reserves to do so. Consequently, late-frost events often result in stark reductions of secondary growth in affected trees. This effect has been widely observed, primarily through tree rings. Tree rings provide a localized, retrospective examination of secondary tree growth in response to frost events, yet they do not allow for quantification of subsequent changes in tree productivity over larger areas let alone for future scenarios.
We bridge this gap by using a network of tree ring data covering past frost events in conjunction with a new version of the DGVM LPJ-GUESS which has been expanded to include representation of late-frost events. The tree ring data covers 30 sites across Bavaria and includes four separate, past late-frost events for which varying degrees of late-frost damage have been previously documented. Using historical climate data (LFU BayObs 5km x 5km spatial resolution) we run simulations at each of the tree ring sites to reproduce the observed data. Subsequently, we run simulations with two versions of LPJ-GUESS, one including the new late-frost module and one without, to directly quantify the changes in tree productivity (NPP) as a result of spring-late frost. Lastly, we force LPJ-GUESS using climate projections to examine how spring late-frost will govern European beech forest productivity under different future scenarios.
Our findings indicate that (1) we are able to accurately reproduce observed late-frost events using the new, late-frost capable version of LPJ-GUESS, (2) spring late-frost events alter productivity dynamics across geographic and climatic regions, and (3) will continue to play a role to varying degrees under different future climate scenarios.
An overview of land-use requirements for solar PV and wind power
Authors: Turkovska Olga , Gruber Katharina , Klingler Michael , Klöckl Claude , Ramirez Camargo Luis , Regner Peter , Wehrle Sebastian , Schmidt Johannes
Published: March 2022

From a superficial reading of the literature on land-use requirements for renewable energy systems, one may conclude that the community has a very clear understanding of how much land is necessary to deploy renewable energy generation technologies. In particular for solar PV and wind power (VRES), the technologies with the highest growth potentials in the coming decades, abundant literature is available. However, a systematic overview is lacking, in particular, concerning approaches used for estimating the requirements, underlying factors that affect the results, and the regional differences.

There is no standard metric that is applied for estimating the land area necessary to accommodate a certain amount of renewable energy capacity. Several different metrics are used for this purpose, including land-use efficiency, land-use intensity, power density, and land occupation, to name a few. E.g., land-use efficiency in one paper can refer to the land area needed to install a certain capacity for energy generation, whereas another paper considers land-use efficiency as the area needed to generate a certain amount of electricity. Therefore, estimates of land-use requirements quantified with the same metrics vary greatly.  

The variability of the land-use requirements is also rooted in the underlying assumptions regarding the area, power-related component, and time of the chosen metrics. However, a systematized review of all aforementioned assumptions on land-use by renewable energies is absent.

Land-use requirements are often derived from the existing VRES facilities. Hence, their values are influenced by such location-specific factors as climatic conditions, orography, land ownership, among others. As land-use requirements are often integrated into the research that estimates potentials for the future deployment of renewable energy, the influence of those factors is implicitly integrated as well. Hence, the potentials for one region may be estimated by applying the data from another region. Although the application of region-specific land-use requirements could reduce the introduced inconsistencies, known land-use requirements are in its vast majority estimated for the US. Therefore, a compilation that in particular gathers literature on land-use of renewable energies in underrepresented world regions is of high importance.
Seasonal climate reconstruction using biogenic carbonates from shallow and deep water lake sediments
Authors: Labuhn Inga , Hammarlund Dan , von Grafenstein Ulrich
Published: March 2022

Carbonate shells from lacustrine organisms provide proxy records of past climatic changes. Their oxygen isotopic composition (δ18O) is controlled by the δ18O of the lake water and by water temperature during carbonate precipitation. The lake water δ18O depends on the δ18O of precipitation in the catchment, which is positively correlated with air temperature in high latitudes. An increasing air temperature therefore leads to an increase in carbonate δ18O. However, the proxy interpretation is complicated by the fact that an increasing water temperature during carbonate precipitation leads to a decrease in carbonate δ18O because of the temperature dependency of isotope fractionation. In the profundal parts of deep lakes, this water temperature change is minimal, and biogenic carbonates mainly reflect lake water δ18O. However, carbonate remains are often much more abundant in shallow water, where water temperature variations can be large.

In this study, we evaluate the possibility to quantitatively reconstruct seasonal temperature changes by combining sediment cores from littoral and profundal Holocene sediments of Lake Locknesjön, Sweden. We measured the isotopic composition of ostracod and mollusk shells and of encrustations from calcifying algae.

In the shallow water sediments, the differences in the mean carbonate δ18O between species can mainly be attributed to seasonal water temperature changes. The lowest δ18O values are observed in Chara encrustations formed during the summer months, and the highest values in adult ostracods, which calcify their valves during the cold season. First isotope measurements on deep water sediments show that the δ18O is higher and less variable than in the shallow sediments. The offsets between species, and between deep and shallow sediments are not constant throughout the Holocene. Assuming a water temperature near 4 °C, biogenic carbonates in the profundal sediments can give insights into the δ18O of lake water and might allow – combined with the abundant measurements from the shallow water cores – a quantification of the seasonal temperature range.
Morphology of magnetic holes in the pristine solar wind
Authors: Trollvik Henriette , Karlsson Tomas , Raptis Savvas
Published: March 2022

Magnetic holes (MHs) are deep depressions in the magnetic field found in the solar wind and in planetary magnetosheaths. Based on Cluster multi-point data from the pristine solar wind, we investigate the morphology of MHs exhibiting no to little rotation in the magnetic field(linear MHs). In a previous study we used timing methods to determine that the MHs were moving with the solar wind, and from that we are now able to determine the spatial scales. We investigate the morphology by comparing observations to theoretical models, starting with infinitely long solenoid model. The scale sizes are related to the orientation parallel and perpendicular to the magnetic field. Here we present the preliminary results, showing a few examples, which later will be expanded to a statistical study.
A survey-based evaluation of farmers’ drought risk reduction strategies in the Po Valley (Northern Italy)
Authors: Bonaccorso Brunella , Borzì Iolanda , Monteleone Beatrice , Martina Mario
Published: March 2022

Drought is the natural hazard producing the most significant impacts on the agricultural sector. In the Mediterranean area, drought-related losses were estimated at approximately 9€ billion/year and this value is going to increase in future climate change scenarios. In this context, implementing proper risk reduction strategies and effective water resources management is fundamental in coping with drought-related water crises.

In this study, a survey has been proposed to farmers of the Po Valley (Northern Italy), in order to identify past drought and heatwaves events that hit their cultivations and to know the strategies implemented to cope with those events.

Farmers were asked to answer questions about the use of irrigation during past droughts and heatwaves, the preferred irrigation strategies during water crises (i.e., irrigate at night, irrigate a reduced area to full irrigation, crop prioritization, etc), the decisional criteria they adopted to establish when to start irrigation during a drought and the availability of insurance coverage.

Past droughts have been identified using the Standardized Precipitation and Evaponstrspiration Index (SPEI) and compared with the ones identified through the survey, highlighting two main drought events: the first one occurred in June 2003 and the other one in August 2019. This last event has been analysed in detail. Survey’s results reveal that, even if the 2003 event was more severe than that one in 2019, since all the farmers decided to irrigate their cultures during the 2003 drought, yield reduction was less than in 2019, when half of the farmers decided to not irrigate their crops during the drought event. In particular, the mean yield reduction for farmers who irrigated their crops during drought events was 35% less than for those who decided to not irrigate.

It was also found that droughts occurring in different plant growth stages have caused very different economic damages in terms of yield reduction, the amount of water resources allocated, and thus the irrigation expenses.

Regarding insurance coverage and the corresponding farmers’ grade of satisfaction, the survey’s responses revealed that farmers who applied irrigation didn’t acquire insurance coverages, and farmers who haven’t used irrigation trusted more on insurance.
Organic carbon fluxes in intermittent springs
Authors: Feld Annika , Fasching Christina , Reiss Martin , Chifflard Peter
Published: March 2022

Springs link the terrestrial and the aquatic ecosystem and connect groundwater and surface water. They are distinguished primarily by their type and discharge, whereby the latter can influence the biogeochemistry. Perennial springs, characterized by continuous spring discharge, show stable conditions and relatively low organic carbon contents. Although previous studies have investigated the sources of dissolved organic carbon (DOC) in streams considering mainly the riparian zone, the hyporheic zone and the hillslopes, our current understanding of springs as sources of organic carbon (OC) is still limited. Thus, our study focuses on intermittent springs, which are particularly vulnerable to climate change induced decreased groundwater levels. Additionally, changing groundwater levels may further increase the frequency of springs with an interrupted discharge during dry periods. Intermittent springs with a temporarily loss of the connectivity to the groundwater, impacting the quantity and quality of received OC and consequently the in-stream respiration, may lead to changed OC quantity and quality transported to downstream ecosystems.

The aim of this investigation is to quantify the export fluxes of OC and to analyze their origin and composition in intermittent springs. For this purpose, 40 springs at four study sites in different low mountain range regions in Germany (Sauerland, Ore Mountains, Hesse Mountains and Black Forest) with different geology and vegetation types will be instrumented with hydrological on-site-measurements for discharge and electrical conductivity. Continuous quarterly biogeochemical sampling campaigns will be carried out and event-based sampling with an autosampler during 4 rainfall events at one spring per site is intended. Additionally, analyses of groundwater, soil water and precipitation samples as well as fDOM and CO2 measurements are implemented. Stable water isotopes (δ2H, δ18O) and nutrient concentrations (PO4, NO3, NH4) will also be determined to enable flux modelling. In this project the combination of continuous measurements and frequent sampling campaigns will be used to gather long-term data with high temporal resolution. Thus, the seasonal dynamics and spatio-temporal variability of OC export fluxes as well as event-based changes in OC and nutrient status and further the influence of spring OC on the following headwater streams will be studied in the next three years. First results show that there are great spatial variabilities in DOC concentration between the 40 intermittent springs in the four study catchments. This underscores that intermittent springs differ substantially from perennial springs in their export behavior.
Source parameters and locations of the 1949 Mw7.4 Khait and 1907 Mw7.6 Karatag earthquakes: implications for how mountain ranges collide
Authors: Johnson Ben , Kulikova Galina , Bergman Eric , Krueger Frank , Pierce Ian , Hollingsworth James , Copley Alex , Kendall Mike , Walker Richard
Published: March 2022

The 1949 Mw7.4 Khait and 1907 Mw7.6 Karatag earthquakes are the two largest earthquakes of the last ~100 years within Tajikistan, in a zone of convergence between the Pamir and Tian Shan ranges at a rate of ~1cm/yr. The historical nature of these events means seismological and geodetic data are lacking. As such, their locations and source parameters have been very uncertain – preventing our understanding of how they fit into the tectonic model of the north-western Pamir.  

Here we present calibrated earthquake relocations for the 1949 earthquake and focal mechanisms determined from digitised seismograms for the 1949 and 1907 earthquakes. We also present a catalog of precise relocations for moderate magnitude earthquakes from 1949 to the present in vicinity of the Vakhsh Thrust. Finally, we present earthquake surface rupture mapping from the Vakhsh Valley, determined from ultra-high resolution elevation models derived from satellite stereo-imagery.  

We find that the 1949 Khait earthquake did not occur on the Vakhsh Fault, a major right-lateral fault that bounds the northern margin of the Pamir, as previously thought. Instead it occurred on an unmapped fault in the Tian Shan basement. However, 10-20m scarps observed on the south Vakhsh valley show this fault is capable of producing large earthquakes. This tells us the Pamir–Tian Shan convergence is distributed across several basement faults capable of producing large earthquakes. It also tells us that the largest earthquakes may occur on faults which may appear minor in the landscape, which has implications for seismic hazard in the region.  