bluuebunny/crossref_metadata_2025 huggingface dataset:
Sea-level rise: from global perspectives to local services
Authors: Durand Gael , van den Broeke Michiel R. , Le Cozannet Gonéri , Edwards Tamsin L. , Holland Paul R. , Jourdain Nicolas C. , Marzeion Ben , Mottram Ruth , Nicholls Robert J. , Pattyn Frank , Paul Frank , Slangen Aimée B.A. , Winkelmann Ricarda , Burgard Clara , van Calcar Caroline J. , Barré Jean-Baptiste , Bataille Amélie , Chapuis Anne
Published: March 2022

Coastal areas are highly diverse, ecologically rich, regions of key socio-economic activity, and are particularly sensitive to sea- level change. Over most of the 20th century, global mean sea level has risen mainly due to warming and subsequent expansion of the upper ocean layers and the melting of glaciers and ice caps. Over the last three decades, increased mass loss of the Greenland and Antarctic ice sheets has also started to contribute significantly to contemporary sea-level rise. The future mass loss of these ice sheets, which combined represent a sea-level rise potential of ~65 m, constitutes the main source of uncertainty in long-term (centennial to millennial) sea-level rise projections. Improved knowledge of the magnitude and rate of future sea-level change is therefore of utmost importance. Moreover, sea level does not change uniformly across the globe, and can differ greatly at both regional and local scales. The most appropriate and feasible sea level mitigation and adaptation measures in coastal regions strongly depend on local land use and associated risk aversion. Here, we advocate that addressing the problem of future sea-level rise and its impacts requires (i) bringing together a transdisciplinary scientific community, from climate and cryospheric scientists to coastal impact specialists, and (ii) interacting closely and iteratively with users and local stakeholders to co-design and co-build coastal climate services, including addressing the high-end risks. Following these principles, as also adopted in the EU project “Projecting sea-level rise: from projections to local implications” (PROTECT), we encourage the formation of research consortia that cover the entire knowledge chain. In this way global sea-level science can be linked to effective coastal climate services at the scale of risk and adaptation
Long-term survival of detrital gold in glaciated landscape based on cosmogenic 3He in detrital grains from Scotland 
Authors: Carracedo Plumed Ana , di Nicola Luigia , Olive Valerie , Stuart Fin
Published: March 2022

The ability to measure cosmogenic 3He from individual detrital mineral grains [1] provides the potential to tease out details of sediment storage and transport that are unavailable from bulk sample analysis, and may, for instance, shed light on the conditions necessary to form economic alluvial placer deposits. While extremely long exposure histories have been measured in detrital grains from unglaciated regions [1], the effect of repeated glacial cycles in removing economically valuable detrital minerals is unknown. Here we report the cosmogenic 3He content of 36 (2-50 mg) native gold grains from the beds of 8 streams in upland Scotland in order to determine their ability to survive glaciation.

Measured 4He concentrations vary from 4 to 299 x 1013 atoms/g these variation on the 4He concentrations may be related to the presence of U and Th in the mineral lattice or U- and Th-rich mineral inclusions. Based on measured Li contents (<1 ppb) the nucleogenic 3He contribution in all samples is negligible. Minimum cosmogenic 3He exposure ages have been determined using production rate of 25 atoms/g/year and assuming no shielding.  33 grains yield exposure ages that are consistent with survival of detrital gold from before the Last Glacial Maximum (i.e > 20 Ka). These grains yield ages up to 4 Ma.   This implies that a significant proportion of the detrital gold has survived several glacial cycles and may have implications for long-term preservation of economic minerals in glaciated regions.

 

[1] O. Yakubovich, F.M. Stuart, A. Nesterenok & A. Carracedo (2019). Chemical Geology 517, 22-33.
Exploring the impact of climate change for biological climate variables using observations and multi-model initial condition large ensembles
Authors: Bowden Jared , Suarez-Gutierrez Laura , Terando Adam J. , Rubenstein Madeleine , Carter Shawn , Weiskopf Sarah , Nguyen Hai Thanh
Published: March 2022

Species are expected to shift their distributions to higher latitudes, greater elevations, and deeper depths in response to climate change, reflecting an underlying hypothesis that species will move to cooler locations.  However, there is significant variability in observed species range shifts and differences in exposure to climate change may explain some of the variability amongst species.  But this requires identifying regions that have experienced detectable changes in those aspects of the climate system that species are sensitive to. 

To better understand species exposure to climate change, we estimate the time of emergence of climate change for 19 biologically relevant climate variables using observations and initial condition large ensembles from five different climate models.   The time of emergence (ToE) is calculated using Signal/Noise (S/N) thresholds.  The S/N threshold applied in this study is >=2, but this threshold can be easily modified to represent species that are more or less sensitive to climate change.  Preliminary findings from the initial condition large ensembles indicates the strongest emergence for the temperature metrics within the tropical oceanic regions in the absence of upwelling. The earliest emergence over the oceans is found within the western warm pool of the Pacific.  Notable places that haven’t emerged for the temperature metrics include both the North Atlantic and Pacific.  The ToE of a climate change signal for the temperature metrics over land is spatially complex, which may partially explain the complex observed range shifts for terrestrial species.  For instance, multiple initial condition large ensembles indicate a signal has emerge in the most recent decades only for the western and northeastern parts United States.
Reading Between the (Shore)Lines: Real-Time Analytical Processing to Monitor Coastal Erosion
Authors: Anthis Zach
Published: March 2022

With the far-reaching impact of Artificial Intelligence (AI) becoming more acknowledgeable across various dimensions and industries, the Geomatics scientific community has reasonably turned to automated (in some cases, autonomous) solutions while looking to efficiently extract and communicate patterns in high-dimensional geographic data. This, in turn, has led to a range of AI platforms providing grounds for cutting-edge technologies such as data mining, image processing and predictive/prescriptive modelling. Meanwhile, coastal management bodies around the world, are striving to harness the power of AI and Machine Learning (ML) applications to act upon the wealth of coastal information, emanating from disparate data sources (e.g., geodesy, hydrography, bathymetry, mapping, remote sensing, and photogrammetry). The cross-disciplinarity of stakeholder engagement calls for thorough risk assessment and coastal defence strategies (e.g., erosion/flooding control), consistent with the emerging need for participatory and integrated policy analyses. This paper addresses the issue of seeking techno-centric solutions in human-understandable language, for holistic knowledge engineering (from acquisition to dissemination) in a spatiotemporal context; namely, the benefits of setting up a unified Visual Analytics (VA) system, which allows for real-time monitoring and Online Analytical Processing (OLAP) operations on-demand, via role-based access. Working from an all-encompassing data model could form seamlessly collaborative workspaces that support multiple programming languages (packaging ML libraries designed to interoperate) and enable heterogeneous user communities to visualize Big Data at different granularities, as well as perform task-specific queries with little, or no, programming skill. The proposed solution is an integrated coastal management dashboard, built natively for the cloud (aka leveraging batch and stream processing), to dynamically host live Key Performance Indicators (KPIs) whilst ensuring wide adoption and sustainable operation. The results reflect the value of effectively collecting and consolidating coastal (meta-)data into open repositories, to jointly produce actionable insight in an efficient manner.
Galactic cosmic rays as signatures of interplanetary transients
Authors: Dumbovic Mateja
Published: March 2022

Coronal mass ejections (CMEs), interplanetary shocks, and corotating interaction regions (CIRs) drive heliospheric variability, causing various interplanetary as well as planetary disturbances. One of their very common in-situ signatures are short-term reductions in the galactic cosmic ray (GCR) flux (i.e. Forbush decreases), which are measured by ground-based instruments at Earth and Mars, as well as various spacecraft throughout the heliosphere (most recently by Solar Orbiter). In general, interplanetary magnetic structures interact with GCRs producing depressions in the GCR flux. Therefore, different types of interplanetary magnetic structures cause different types of Forbush decreases, allowing us to distinguish between them. With new modelling efforts, as well as observational analysis we are one step closer in utilizing GCR measurements to provide information on interplanetary transients, especially where other measurements (e.g. plasma, magnetic field) are lacking.
Force measurements during snow stability tests
Authors: Griesser Silke , Reiweger Ingrid
Published: March 2022

A very powerful and commonly used method to assess the danger of avalanche release on a slope is the performance of snow stability tests. The present work aims to contribute towards a better understanding of snow stability test results by conducting force measurements during a snow stability test, namely the Compression Test (CT). We were particularly interested in the variability of the force applied to a potential weak layer during the test by different persons and for different snow covers. We therefore focused on the stress levels for the single taps and loading steps of a CT, and how they were influenced by different snow properties (effective depth, compaction depth, and snow hardness) as well as other factors, such as test subjects’ body weight and arm length. We used two capacitive pressure sensors to conduct force measurements during the performance of CTs at two different depths with eleven different people and at seven different locations. The evaluation and analysis of these measurements were conducted with Python. Our results showed that the penetration depth and compaction of the snow above the force sensor significantly influenced the transmission of stress. The stress levels of shoulder taps were in the range of stress levels below a standing skier and decreased non-linearly with penetration depth. Furthermore, we found that stress levels were rising also within distinct loading steps. Moreover, it was possible to confirm the influence of a person’s weight and arm length on stress levels, and consequently, statistically significant differences between different test persons. In terms of avalanche safety, our results indicate a non-linear decrease of the probability of fracture initiation with increasing tap number. Most importantly, we discovered that regardless of what was analysed, the data’s scattering decreased with increasing depth, which means that the significance of a CT result increased considerably with increasing fracture depth.
Experimental investigation on the mechanical properties of shale soaked in supercritical CO₂ / water at dynamic pressures
Authors: Lyu Qiao , Wang Kaixi , Tan Jingqiang , Wood David
Published: March 2022

As shale gas exploitation proceeds, reservoir pressure progressively decreases. While using CO2 or water to enhance shale gas recovery, it is important to investigate their effects on the mechanical properties of shale under dynamic pressure conditions. In this study, we have investigated the effects of supercritical CO2 and water immersion on the mechanical properties of shale under different dynamic pressures (pressure change 1: decreasing from 20 MPa to 8 MPa; pressure change 2: decreasing from 42 MPa to 30 MPa). The testing results indicate that, after soaking in supercritical CO2 and water, the uniaxial compressive strength (UCS) of shale is decreased by 51.05% and 58.36% (pressure change 1), and by 35.98% and 36.84% (pressure change 2), respectively. The strength and Young's modulus of shale are decreased more significantly after water immersion compared to supercritical CO2 immersion. Due to the matrix compression effects, the mechanical properties of shale are changed more significantly under lower imbibition pressures. Supercritical CO2 immersion leads to an increase in the Poisson's ratio along with more complex fracture patterns, whereas water immersion results in a slight decrease in the Poisson's ratio associated only with shear fracture formation. The acoustic emission (AE) signals display obvious stage characteristics during the compressional deformation of the samples, and the AE energy is mainly generated in during the unstable crack propagation stage. Supercritical CO2 immersion plays an important role in crack generation, whereas water immersion is dominated by the alteration of the pore structure. Compared with the constant pressure imbibition, the dynamic pressure imbibition changes the microstructure of shale and weakens its mechanical properties more significantly. The results of this study provide a clearer understanding of the effects of CO2 and water on the mechanical properties of shale during exploitation of shale gas.
GPR Prospecting Close to a Roman Amphitheatre in an Urban Environment
Authors: Persico Raffaele , Muci Giuseppe
Published: March 2022

In the present contribution we will present the results of a GPR [1-3] measurement campaign performed in St. Oronzo Square, Lecce, Italy, aimed to investigate and monitor the status of the Roman amphitheatre present in the square. The “ambulacra” of this amphitheatre in particular are currently buried under the square and only partially accessible. Also, further part of the amphitheatre are still buried, and cannot be excavated because of the presence of posterior structures, in some cases of historical relevance in their turn. The georeferencing of the results has been achieved in QGIS. Indeed, no GPS was available when the measurements were performed. However, the shape of the prospected areas, wedged in the ways around the amphitheatre has allowed a correct georeferencing. A home-made MATLAB code has helped to this pros.

 

References

[1] R. Persico, S. D'Amico, L. Matera, E. Colica, C. De, Giorgio, A. Alescio, C. Sammut and P. Galea, GPR Investigations at St John's Co-Cathedral in Valletta, Near Surface Geophysics 17, 3, 2019, pp. 213-229. doi: 10.1002/nsg.12046.

[2] E. Colica, A, Antonazzo, R. Auriemma, L. Coluccia, I. Catapano, G. Ludeno, S. D’Amico, R. Persico, GPR Investigation at the Archaeological Site of Le Cesine, Lecce, Italy, Information 2021, 12, 412, https://doi.org/10.3390/info12100412

[3] G. Gennarelli, I. Catapano, F. Soldovieri, R. Persico, On the Achievable Imaging Performance in Full 3-D Linear Inverse Scattering, IEEE Trans. on Antennas and Propagation,  63, 3, March 2015, pp. 1150-1155.
Factors Influencing the Awareness and Adoption of Borehole-Garden Permaculture in Malawi: Lessons for the Promotion of Sustainable Practices
Authors: Hinton Rebekah , Macleod Christopher , Troldborg Mads , Wanangwa Gift , Kanjaye Modesta , Mbalame Emma , Mleta Patrice , Harawa Kettie , Kumwenda Steve , Kalin Robert M.
Published: March 2022

Using wastewater accumulating around rural waterpoints to irrigate community gardens, borehole-garden permaculture presents a method of local sustainable water management. Alongside this, borehole-garden permaculture also presents public health benefits through the removal of stagnant water around boreholes, key Malaria breeding grounds, and through providing year-round food to supplement diets. By analysing a dataset of over 100,000 cases, this research examines the awareness and adoption of borehole-garden permaculture across Malawi. Generalised linear models identified significant variables influencing borehole-garden permaculture awareness and uptake revealing that socioeconomic, biophysical, and waterpoint-specific variables influenced both the awareness and adoption of borehole-garden permaculture. While 43.0% of communities were aware of borehole-garden permaculture uptake in Malawi was low; only 2.4% of communities surveyed were practising borehole-garden permaculture. Communities in areas with unreliable rainfall and high malaria susceptibility had low borehole-garden permaculture awareness despite borehole-garden permaculture being particularly beneficial to these communities. This work suggests that future work in the promotion of borehole-garden permaculture should focus their efforts within these areas. Furthermore, this work highlights the value of community networks in knowledge sharing and suggests that such social capital could be further used by NGOs and the Government of Malawi in the promotion of borehole-garden permaculture and other sustainable practices in water management. 
Brittle failure at high-pressure conditions: the key role of reaction-induced volume changes
Authors: Yamato Philippe , Duretz Thibault , Baïsset Marie , Luisier Cindy
Published: March 2022

Metamorphic reactions can lead to drastic changes in rocks mechanical properties. Indeed, during such transformations, the nucleation of new phases with different strength, grain size and/or density compared to the primary phases is enhanced, and transient processes due to the ongoing reaction are then activated.

Eclogitization of lower crustal rocks during continental subduction constitutes an emblematic transformation illustrating these processes. In such tectonic context, it has been shown that eclogitization seems to be closely associated with the occurrence of seismogenic events. However, the mechanisms that trigger brittle failure in such high pressure environments remain highly debated. Indeed, whether the change in density or the change in rheology can lead to embrittlement is still enigmatic.

By using 2D compressible mechanical numerical models we studied the impact of the strong negative volume change of the eclogitization reaction on the rocks rheological behaviour. We show that eclogitization-induced density change occurring out of equilibrium can, by itself, generates sufficient shear stress to fail the rocks at high-pressure conditions.

Rupture initiation at depth in continental subduction zones could therefore be explained by volume changes, even without considering the modifications of the rheological properties induced by the transformation. Our results also indicate that the negative volume change associated with brittle failure can enhance the propagation of the eclogitization process by a runaway mechanism as long as the reaction is not limited by the lack of reactants.

 
Are initial phases of seismic swarms driven by a cascade of events or precursory slow slip?
Authors: Jiang Yu , González Pablo
Published: March 2022

Resolving fine temporal stressing rate changes can provide crucial information on the driving mechanisms leading to observed seismicity rate change and surface deformation signals and favours the distinguish of various earthquake nucleation hypotheses, e.g., the preslip model and the cascade model. The initial phase of seismic swarms might be an interesting candidate, because (1) the long-duration seismicity during seismic swarms provide us with better chances to reveal any stress change evolution, and (2) significant seismic slip is expected to occur caused by the most energetic event, which could bias our analysis of slow slip existence, while the initial phase contains much less seismic slip.

In this research, we revisit the 2011 Hawthorne seismic swarm (Nevada, USA) with well-recorded seismicity and abundant geodetic data, and test whether the derived observables can distinguish between two distinct slip nucleation hypotheses (cascade and preslip models). Firstly, to support the cascade model, we calculate the Coulomb stress change from the geodetic-estimated fault slip models, which allows us to analyse the spatio-temporal distribution of seismicity. Secondly, to test the preslip model, a modified rate-and-state model is proposed to connect the seismicity rate to the shear stressing rate, which is derived from a new slip history function - a logistic function. We apply this new method to the 2011 Hawthorne seismic swarm, and estimate the shear stressing rate history. The results show that: (1) A slow slip event is required to explain the observed deformation and seismicity in the initial phase of the swarm. Although the seismicity can be triggered by preceding nearby earthquakes, the cascade model alone cannot explain the observed surface deformation signals. (2) Slow slip is accelerating during the initial phase, and this pattern is consistent with the acceleration of slip during the nucleation of ruptures observed in laboratory experiments and numerical simulations. (3) The most energetic event (M4.6) could have been triggered by a slow slip event, nearby preceding seismicity, or both of them. 

The study of the initial phase during the 2011 Hawthorne seismic swarm allows us to explore the driving mechanism leading to the spatio-temporal evolution of seismicity. We conclude that the slow slip is required to interpret the surface deformation and recorded seismicity, and the triggering of the observed earthquakes in a cascade model cannot be ruled out. This study contributes to providing a new method to model the shear stressing history, which helps to illuminate the physics of the nucleation of earthquakes and the role of slow fault slip in the future.
Modelling stream temperature with multiple hydroclimatological temperature models
Authors: Duan Zheng , Duggan Edward , Tuo Ye , Li Yuying , Dong Jianzhi , Liu Junzhi , Gao Hongkai
Published: March 2022

Stream temperature is an important parameter to evaluate the water quality and biodiversity in aquatic ecosystems. Climate change and human activities (e.g. land use change) are affecting stream temperature, potentially leading to negative impacts on the habitats of native species and sustainability of aquatic ecosystems. Therefore, it is important to monitor and understand stream temperature under different conditions to better protect the aquatic ecosystems. The conventional in-situ measurements from gauge stations provide the most accurate stream temperature data, but they are often sparse and limited in terms of data length (temporal) and spatial coverages (many regions have no measurements). Stream temperature modelling is an effective way to extrapolate from limited measurements in both space and time, and it is the only way to predict the future to assess the climate change impacts. The stream temperature is influenced by meteorological and hydrological factors, and the relationship between the stream temperature and physical conditions is complex and can vary spatially and temporally. Different statistical and process/physically-based stream temperature models have been developed with the latter generally performing better. The Soil and Water Assessment Tool (SWAT) is a semi-distributed process-based hydrological model built with a simple statistical model to simulate stream temperature using only air temperature. Two hydroclimatological stream temperature models were recently developed to improve the capability of the SWAT model for simulation of stream temperature by considering influences of hydrological conditions and more detailed water-air heat transfer processes. The two recently developed models were tested mainly in a few river basins in U.S. and Canada. This study aims to compare and evaluate -for the first time- the performance of three models in simulating stream temperature in the Vils Basin located in Bavaria, Germany. The SWAT model is first calibrated and validated against the measured streamflow at the basin outlet on a daily timescale to ensure satisfactory streamflow simulation. Then the three different stream temperature models are run and evaluated with measured stream temperature at both daily and monthly time scales. The parameters and simulation results from the three different stream temperature models are analyzed. This study complements existing studies to improve our understanding of the performance of different stream temperature models in different river basins.
Optically stimulated luminescence dating of relic charcoal kilns using sand-sized quartz: a status report
Authors: Karimi Moayed Nasrin , Vandenberghe Dimitri , Buylaert Jan-Pieter , Deforce Koen , Debeer Ann-Eline , Biernacka Paulina , De Smedt Philippe , De Clercq Wim , De Grave Johan
Published: March 2022

Charcoal has been produced for centuries, even millenia, in and near forested areas in Europe. The relics are increasingly studied to inform, e.g., on forest composition and woodland exploitation, the effects of biochar on soil properties and plant nutrients, and carbon sequestration. All these studies require a chronological framework, which is most commonly established using radiocarbon (14C) dating. In NW Europe, however, many relic charcoal kilns have been found to post-date 1650 CE. Owing to limitations imposed by the calibration curve for the last few centuries, 14C dating results in wide age probability distributions; this implies that the method does not allow resolving the chronology for post-1650 CE features.

In this study, we report on our experiences with optically stimulated luminescence (OSL) dating as a complementary and alternative method to 14C. The approach uses sand-sized quartz extracted from sediments that were heated during charcoal production. Our study comprises relic charcoal kilns on silty and sandy subsurfaces in Belgium (Sonian and Zoersel forest), The Netherlands (The Veluwe) and France (Grand-Est region). We first demonstrate that OSL dating can yield accurate and precise ages by comparing our results for pre-1650 CE features with independent (14C) age information. Intricacies, possibilities and limitations are discussed. For most of the features, widely adopted OSL procedures can be applied; for one of the study areas (Zoersel forest, in the northern Belgian sand belt), dedicated analysis using single grains of quartz is the method of choice. We then apply our methodology to post-1650 CE features, for which 14C dates and or historical information is available. We show that, for the majority of the investigated features, accurate OSL ages can be obtained with a precision that is similar or significantly better compared to independent age information. A considerable added value is the potential of OSL dating to distinguish between multiple features at one or comparable sites with an unprecendented time-resolution of 5 - 40 years (and 95.4% probability).  

 

 Keywords: OSL dating; radiocarbon dating; relic charcoal kiln; Modern age; natural resources.
Geostatistical Gravity Inversion for Estimating Sub-Ice-Bathymetry
Authors: Liebsch Jonas , Ebbing Jörg , Eisermann Hannes , Eagles Graeme
Published: March 2022

Sub-ice-bathymetry is an important boundary condition when modelling the evolution of ice shelves and ice sheets. Radar sounding is a proven method to reveal the sub-ice-topography beneath grounded ice. However, it fails to image the bathymetry beneath the floating ice shelves due to the strong radar reflectivity of sea water. As an alternative, the inversion of gravity measurements has been used increasingly frequently in recent years. To overcome the ambiguity of inverse modelling, this method benefits from independent depth constraints derived from direct measurements distributed throughout the model area, such as by active seismic, hydroacoustic, and radar methods.

Here, we present a novel geostatistical approach to gravity inversion and compare it to the classical and more commonly used FFT approach. Instead of only fitting individual points, we also include the spatial continuity of the sub-ice morphology. To do so, we calculate a variogram that fits the available depth measurements and derive a covariance matrix from it. The covariance matrix and an initial bathymetry model obtained by kriging together describe an a-priori probability density. For the inversion, the model bathymetry is related to the measured gravity using a quasi-Newton method, for which the derived probability density serves as the inversion’s regularization term. We successfully apply the algorithm to airborne gravity data across the Ekström ice shelf (Antarctica) and compare our results with those of previous studies based on the classical approach. The simplified addition of constraints both for the geometry and the density structure in our approach proves to be advantageous.
Assessment of post-seismic landslide susceptibility using an index representative of seismic cracks 
Authors: Kasai Mio , Yamaguchi Shui
Published: March 2022

In an area experienced a strong earthquake, the formation of clusters of seismic cracks is considered related to susceptibility to post-seismic slides. However, the relationship between crack distribution and the occurrence of post-seismic slides has rarely been evaluated. This study developed an index representing the spatial density of seismic cracks (dense crack index: DCI) for the area where post-seismic slides were identified after the 2016 Kumamoto earthquake (Mw 7.0). The susceptibility of post-seismic slides was then assessed using models that incorporated the weight of evidence (WoE) and random forest (RF) methods, with the DCI as a conditioning factor. Both the models confirmed the importance of the DCI, although the improvement in model performance as indicated by area under the curve values was marginal or negligible by including the index. This was largely because the combination of features that indicated where open cracks were likely to occur, or ridgelines where seismic waves were prone to be amplified, could compensate for the absence of the index. The contribution of the DCI could be improved if more accurate LiDAR data were used in the analysis.
Erosion controls vegetation recolonization in Draix-Bleone badlands
Authors: Le Bouteiller Caroline , Klotz Sebastien
Published: March 2022

Vegetation and erosion interact with each other through a variety of processes, contributing to the formation and evolution of landscapes. The present work focuses on the humid badlands of Draix-Bleone observatory, in the French Alps. In this observatory, long-term records of hydrology and sediment fluxes are available for several catchments of varying size and vegetation cover. We aim to characterize and quantify the interactions between vegetation and erosion in these badlands.

One the one hand, we previously found that vegetation, where it is able to maintain, strongly limits badland erosion. On the other hand, vegetation recolonization has been observed over the last decades and we hypothesize that this growth is controlled by topographic and erosive mechanisms.

We use aerial images for several dates in the Laval catchment of size 0.86 km2. We classify each image to map vegetation cover and compare the extent of vegetation cover from one date to the other. We then extract the newly vegetated areas and search for environmental factors that can explain why these areas have been colonized rather than others. We combine factors such as slope and drainage area that are related to erosive processes, to biological factors that relate to the dispersion and colonization capacity of previously existing vegetation.

Preliminary findings indicate that vegetation has mainly recolonized areas that are in the vicinity of existing vegetation patches and with low to intermediate slopes. No effect of aspect is found. This suggests that recolonization is limited by erosive processes, but not by water availability.
Numerical prediction of the atmospheric dust process: the way to reduce risks from its adverse effect
Authors: Nickovic Slobodan
Published: March 2022

Mineral dust, one of the most abundant aerosols in the atmosphere, can be transported by winds thousands of kilometers away from its source and deposited on land and sea. In response to growing societal interest in reducing risks from various hazardous dust effects, the World Meteorological Organization has established a long-lasting Sand and Dust Storm Warning Advisory and Assessment System, while the UN formed in 2018 the Coalition to Combat Sand and Dust Storms. Over the last twenty years, thanks to dust-related research, numerical models have been developed which today successfully predict the atmospheric dust process. Such models include dust concentration as a prognostic parameter and can now successfully assess the occurrence of most dust storms. There are numerous impacts of dust on weather, climate, marine and terrestrial ecosystems, many of them with detrimental effects, such as: adverse influence on human health; disruption of ground and aviation transport; reduced agricultural growth; disfunctioning of solar energy panels; and acceleration of snow and ice melting in high-latitudes. This study will present examples illustrating recent efforts to develop user-oriented applications based on the use of dust forecasting products to mitigate the negative impacts of this aerosol.
Aerosols delay the emergence of greenhouse gas forcing on 21st century South Asian monsoon precipitation by several decades
Authors: Singh Jitendra , Marvel Kate , Cook Benjamin , Rajaratnam Bala , Persad Geeta , McDermid Sonali , Singh Deepti
Published: March 2022

Anthropogenic aerosols (AERs) affect several aspects of the climate system across the world through radiative forcing and microphysical effects. These influences are particularly strong across South Asia, where AER concentrations are highest and further projected to increase in coming decades. Using large ensemble experiments from Earth system model, we examine how AERs shape the evolution of seasonal precipitation over South Asia inlate 20th century and 21st century climate in the presence of rising greenhouse gases (GHGs) concentrations. We find that AERs strongly reduce monsoon precipitation, moderately reduce post-monsoon precipitation, and negligibly influence pre-monsoon precipitation. Consequently, AERs delay the emergence of GHG-forced increases in precipitation by ~5 decades in the monsoon season and ~1 decade in the post-monsoon season. However, GHGs are projected to outpace the influence of AERs by mid 21st century, causing a steep intensification of monsoon and post-monsoon precipitation. We further show that local AERs have the strongest influence on precipitation in the monsoon and post monsoon seasons in the near-future (2020-2049). However, the contribution from remote AERs changes is also important in shaping the monsoon precipitation changes over northwestern South Asia. Further, the influence of local AERs monsoon precipitation remains stationary throughout the 21st century, indicating the insensitivity of relationship between local AOD and precipitation to the projected warming. A better understanding of aerosol-climate interactions and associated precipitation responses in is pertinent for policymakers to address the critical aspect of regional consequences over South Asia induced by externally forced climate change.
Soil and climate interactions in the Mediterranean. Are we heading for disaster?
Authors: Ferreira António
Published: March 2022

Soils are by definition important carbon sinks, in particular for non-tropical types of climates, an important part of carbon in ecosystems are located on them. Under climate change, those carbon sinks are placed under stress due to often-subtle changes that modify the conditions for their function and rend them particularly vulnerable to dereliction, reducing the capacity to act as carbon sinks at the long term.

In agricultural soils, the intensification of cropping systems and the reduced addition of organic matter results in a sharp reduction of soils’ organic content, with important impacts on soil functioning, namely in what concerns water and nutrient cycles, which will reduce soil fertility and carbon content on the long run. This will transfer slowly but steadily soil’s organic carbon to the atmosphere, reinforcing climate change.

Forest soils suffer an even more catastrophic impact from climate change, since the regions more vulnerable have a higher frequency and intensity of the big eraser, when the forest systems fail to be in equilibrium with the climate: forest files. They are responsible altogether by the emissions of various compounds to the atmosphere, comparable to the anthropic emissions in a bad forest fire year. The soils derelict by fire lose an important part of environmental services they provide, namely suffer a significant reduction of their capacity to sink carbon. This adds to the instantaneous loss of carbon to the atmosphere during the fire and downstream to aquatic ecosystems thereafter.

We explore methodologies to reduce those losses in wet Mediterranean areas, aiming to increase the carbon sinks to reduce the atmospheric concentrations.
U-series dating of water-table fluctuations in Devils Hole cave (Nevada, USA) over the last 800,000 years
Authors: Steidle Simon Dominik , Wendt Kathleen , Edwards R. Lawrence , Dublyansky Yuri , Spötl Christoph
Published: March 2022

234U-238U is a powerful geochronometer that can provide absolute ages of secondary carbonates over a greater interval of time than the well-established 230Th-U. In this study, we apply 234U-238U dating techniques to subaqueous calcite deposits in Devils Hole cave, located in the Amargosa Desert (Nevada, USA). Subaqueous calcite deposits record paleo water table elevations within the cave. Previous work used 230Th-U dating techniques to reconstruct fluctuations in the local water table over the last 350,000 years (Wendt et al. 2018). We have extended the Devils Hole water table record up to and beyond the 230Th-U dating limit using both 230Th-U and 234U-238U dating techniques. Precise control (±60.5‰) of the initial 234U/238U ratio is possible due to its low variability and high correlation with δ13C and δ18O (Li et al., 2020). Resulting 234U-238U age uncertainties are on the order of ±16,000 years for 800,000-year old calcite. The new 234U-238U ages allow us to extend the Devils Hole water-table record across the full range of deposition. The resulting 800,000-year record reveals local water-table fluctuated on glacial-interglacial times scales, reaching maximum heights of 20m above modern-day levels. The observed orbital- to millennial-scale fluctuations are interpreted to be primarily driven by climate. Assessing the sensitivity of the Devils Hole water table to various climate modes is key to predicting future water availability in this water-stressed region.

 

Wendt, K. A., Dublyansky, Y. V., Moseley, G. E., Edwards, R. L., Cheng, H. & Spötl, C., 2018, Moisture availability in the southwest United States over the last three glacial-interglacial cycles Science Advances, 4, https://doi.org/10.1126/sciadv.aau1375.

Li, X.; Wendt, K. A.; Dublyansky, Y.; Moseley, G. E.; Spötl, C. & Edwards, R. L., 2020 Novel method for determining 234U-238U ages of Devils Hole 2 cave calcite, Geochronology, https://doi.org/10.5194/gchron-2020-26
Moisture Budget Closure of Arctic Atmospheric Rivers from Saw-Tooth Flight Pattern – A Feasibility Study in High-Resolution Model Data
Authors: Dorff Henning , Konow Heike , Schemann Vera , Ament Felix
Published: March 2022

This study investigates in a synthetic way to what extent saw-tooth flight patterns from long-range research aircrafts can close the moisture budget of arctic atmospheric rivers (ARs). Such ARs dominate the moisture transport into the Arctic. The analysis of the moisture budget in AR corridors is key to understand the spatiotemporal AR evolution, resulting air mass transformations along their pathway and precipitation efficiency of ARs. However, the determination of moisture budget components in arctic ARs is challenging due to sparse observations. Dedicated research flight campaigns require the quantification of divergence of integral water vapour transport (IVT) using dropsondes along AR cross sections and remote sensing capturing internal water vapour load and precipitation rate. However, limited number of dropsondes and curtain-restricted remote sensing may deteriorate the AR moisture budget. Uncertainties in airborne representation of AR moisture components have to be assessed. We consider seven arctic ARs from spring season of last decade. They cover pathways over the North Atlantic and Siberia and a broad range of AR conditions representative for the Arctic. To assess airborne budget closure capabilities, we include outputs from the new C3S Arctic Regional Reanalysis (CARRA) and simulations from an adapted ICON model configuration. Both have a horizontal resolution of around 2.5 km and deliver reasonable AR representation with high spatial variability in moisture budget components. By generating synthetic flights and mirroring airborne observations (e.g. dropsondes) in both gridded datasets, we identify major sources of error that arise in the airborne quantification of IVT variability. We determine the representativeness of total precipitation and hydrometeor content derived from diagonal legs for entire AR sectors. For all ARs, levels where specific humidity and wind speed contribute most to IVT are located below 1500 m. Along horizontal AR transects, maximum IVT values and highest lateral IVT variability are located around low-level jets. Frequent soundings near the low-level jet are fundamental to lower uncertainties in moisture flux convergence that dominate against other budget terms. In CARRA, having less than six soundings within the AR cross-section causes biases of total IVT by more than 10 %. Samples along diagonal flight legs through AR sectors can reproduce mean internal precipitation rate, whereas the statistical distribution of hydrometeor contents for the entire sector differs due to the complex cold-front composition near the AR. Evaporation shows minor budget contributions in arctic ARs. While moisture convergence uncertainties are highest close to the AR centre, uncertainty of precipitation rate increases in the AR outflow region. Moreover, we give first insights on very preliminary observations from the HALO-(AC)³ flight campaign in March and April, 2022.
Mantle viscosity derived from geoid and different land uplift data in Greenland
Authors: Bagherbandi Mohammad , Amin Hadi , Wang Linsong , Shirazian Masoud
Published: March 2022

The Earth’s mass redistribution due to deglaciation and recent ice sheet melting causes changes in the Earth’s gravity field and vertical land motion in Greenland. The changes are because of ongoing mass redistribution and related elastic (on a short time scale) and viscoelastic (on time scales of a few thousands of years) responses. These signatures can be used to determine the mantle viscosity. In this study, we infer the mantle viscosity associated with the glacial isostatic adjustment (GIA) and long-wavelength geoid beneath the Greenland lithosphere. The viscosity is determined based on a spatio-spectral analysis of the Earth’s gravity field and the land uplift rate in order to find the GIA-related gravity field. We used and evaluated different land uplift data, i.e. the vertical land motions obtained by the Greenland Global Positioning System (GPS) Network (GNET), GRACE and Glacial Isostatic Adjustment (GIA) data. In addition, a  combined land uplift rate using the Kalman filtering technique is presented in this study. We extract the GIA-related gravity signals by filtering the other effects due to the deeper masses i.e. core-mantle (related to long-wavelengths) and topography (related to short-wavelengths). To do this, we applied correlation analysis to detect the best harmonic window. Finally, the mantle viscosity using the obtained GIA-related gravity field is estimated. Using different land uplift rates, one can obtain different GIA-related gravity fields. For example, different harmonic windows were obtained by employing different land uplift datasets, e.g. the truncated geoid model with a harmonic window between degrees 10 to 39 and 10 to 25 showed a maximum correlation with the GIA model ICE-6G (VM5a) and the combined land uplift rates, respectively. As shown in this study, the mantle viscosities of 1.6×1022 Pa s and 0.9×1022 Pa s for a depth of 200  to 650  km are obtained using ICE-6G (VM5a) model and the combined land uplift model, respectively, and the GIA-related gravity potential signal.
Methane emissions from upstream oil and gas production in Canada are underestimated
Authors: Risk David , MacKay Katlyn , Lavoie Martin , Bourlon Evelise , Atherton Emmaline , O'Connell Elizabeth , Baillie Jennifer , Fougere Chelsea , Khaleghi Afshan , Coyle Lindelwa , Vogt Judith
Published: March 2022

Methane emissions were measured at ~7000 sites across major oil and gas producing regions in Canada to examine regional emission trends, and to derive an inventory estimate for Canada’s upstream oil and gas sector. Emissions varied by fluid type and geographic region, with the heavy oil region of Lloydminster ranking highest on both absolute and intensity-based scales. Emission intensities varied widely for natural gas production, where older, low-producing developments showed high emission intensities, and where emissions intensity in newer developments was amongst the lowest in North America. Emissions from offshore production were in-line with reported estimates. When allocated to individual producers, we found that methane emissions intensity varied more than 1000-fold as determined by geographical factors and infrastructure portfolio. Reporting and disclosure frameworks in Canada are improving but we found that producers could easily under-report emissions and emissions intensity if relying only on regulatory requirements. Overall, we estimate that the Canadian upstream oil and gas methane inventory is underestimated by a factor of 1.5, which is consistent with previous studies of individual regions. 