bluuebunny/crossref_metadata_2025 huggingface dataset:
The complexity of water freezing under reduced atmospheric pressure – insights on effusive cryovolcanism from laboratory experiments
Authors: Brož Petr , Patočka Vojtěch , Běhounková Marie , Sylvest Matthew , Patel Manish
Published: February 2023

Exploration of the Solar System has revealed that the surfaces of many icy bodies have been resurfaced by cryovolcanism: a process during which liquid and vapour are released from the surface into extremely cold and low pressure conditions. Water is one of the most commonly released liquids, and its stability and behavior under such conditions are thus of special interest. When exposed to low pressure, water boils, but it may also start freezing at the phase boundary due to evaporative cooling, as indicated by previous studies. There is only limited insight into how exactly the multiple phase transitions interact and what parameters control the dynamics of the system. To overcome this knowledge gap, we performed experiments in which we simulated the release of water at low pressure and low temperatures, such as could be encountered at local conditions at the  surface of an icy moon.We used the Mars Simulation Chamber at The Open University (UK), in which a 60 x 40 cm container containing 5 and 17 litres of water was exposed to a reduced atmospheric pressure of ~4.5 mbar. Deionised water was mixed with a small amount of NaCl to achieve a salinity of 0.5% and was precooled to ~3.8°C to be close to the freezing point. Experiments were documented by video cameras situated around the container and the temperature inside the chamber and of the water was recorded by thermocouples.At the beginning of each experiment, the atmospheric pressure was gradually reduced from ambient, which triggered boiling within the entire volume of water and evaporative cooling in its uppermost layer. This caused a gradual drop in the water temperature down to the freezing point, forming pieces of floating ice. The area where ice was present slowly grew and within timescales of a few minutes the entire surface of the container was covered with ice. However, the ice layer was broken into blocks with uneven surfaces. This was due to active boiling below the freezing layer of the water, with the intense formation of vapour bubbles which were capable of breaking and/or uplifting the ice. Once the fracture(s) developed, trapped vapour was released and deflation followed. Experimental results show that the process was more intense when larger amounts of water were used within the container, which significantly disrupted the freezing of water in those experiments and affected the final topography of the ice layer.Our experiments show that water phase transition during effusive cryovolcanic eruptions are likely to be a highly complex process due to boiling causing major ice fracturing and the formation of topographical anomalies on the frozen surface.
Look ahead! Future projections of phytoplankton communities are altered by interactive effects of environmental drivers
Authors: Seifert Miriam , Nissen Cara , Rost Björn , Vogt Meike , Völker Christoph , Hauck Judith
Published: February 2023

Phytoplankton growth is controlled by environmental drivers such as nutrients and light availability, temperature, and the carbonate system. Thereby, changes in one driver can modify the response towards another driver. These interactive effects are usually not considered in large-scale ocean biogeochemistry models, potentially leading to incomplete projections of future phytoplankton biomass. In the presented work, we first parameterized growth sensitivities to changes in the carbonate system. We then used the results of a meta-analysis on interactive driver effects in published phytoplankton laboratory studies to develop model parameterizations for dual driver interactions (carbonate system versus temperature, carbonate system versus light). The parameterizations were tested in the biogeochemistry and phytoplankton functional type model REcoM under present-day and future conditions. While future phytoplankton biomass decreases by a similar amount with and without driver interactions (5-6%), interactive driver effects become visible on a group-specific level. Once driver interactions are considered, the biomass of diatoms and small phytoplankton decreases by -8.1% and -5.0%, respectively, and the biomass of coccolithophores increases by +33.2% from present-day to future conditions on a global scale. In comparison, the biomass of diatoms, small phytoplankton, and coccolithophores changes by 0.0%, -9.0%, and -10.8%, respectively, in simulations without driver interactions. Hence, projections of the global future phytoplankton community shift towards a larger share of small phytoplankton and coccolithophores and a smaller share of diatoms if interactive driver effects are taken into account. Regionally, the effect of driver interactions is largest in the Southern Ocean, where diatom biomass decreases (-7.5%) instead of increases (+14.5%). In conclusion, our study reveals that model projections of future phytoplankton biomass may miss out important information on the future phytoplankton community composition and group-specific direction of change if driver interactions are not considered.
Quantifying karstic geomorphologies using Minkowski tensors and graph theory: Applications to SLAM Lidar data from carbonate caves in Northern Bavaria (Germany)
Authors: Prabhakaran Rahul , Smith Ruaridh , Koehn Daniel , Bruna Pierre-Olivier , Bertotti Giovanni
Published: February 2023

Karstification is a ubiquitous feature in carbonate rocks. The origins can be hypogenic or epigenic based on the source of the reacting fluids. The presence of karstified lithologies and their spatial heterogeneity poses a major risk in subsurface energy utilization goals (hydrocarbons, geothermal etc). Such dissolution features tend to organize as spatial networks, with their evolution controlled by a complex interplay of several factors, including natural mineralogical variations in host rocks, effects of pre-existing structures, directional history of palaeo-flow paths, and competition between convective transport and dissolution. Accurate quantification of the spatial distribution of karst is difficult owing to resolution issues in 3D data such as seismic and ground penetrating radar. Recent advances in Simultaneous Location and Mapping (SLAM) Lidar technology have made possible to acquire karst cave passage geometries at very high-resolution with relative ease compared to conventional terrestrial lidar. In this contribution, we present a unique dataset of more than 80 caves, scanned using SLAM lidar, in Jurassic carbonates from northern Bavaria, Germany. We introduce a methodology for robustly deriving morphometrics of karstic caves using Minkowski tensors and spatial graph theory. The method is based on a combination representation of cave passage skeletons as spatial graphs and 2D passage cross-sections using Minkowski functionals. The enriched topological representation enables detailed analysis of internal spatial variation within a single cave and also comparison with cave geometries from other caves. We derive a typology of cave systems based on the degree of structural control on karstification using the database.
High vulnerability of highland Andean forests to warming
Authors: Mercado Lina , Restrepo Zorayda , Gonzalez-Caro Sebastian , Hartley Iain , Villegas Palacio Juan , Meir Patrick
Published: February 2023

Tropical forests are expected to be highly vulnerable to climate change. Observations from the tropical montane Andean forests report a change in composition towards a greater relative abundance of warm affiliated species, i.e thermophilic species. These shifts are hypothesised to result from differential responses to warming of cold- and warm-affiliated species, with the former experiencing mortality and the latter migrating upslope. However, the drivers of these changes are poorly understood. Along a 2000m altitudinal gradient/thermosequence in the Colombian Andes, we planted 2-yr old individuals of cold- and warm-affiliated species under common soil and water conditions, exposing them to the hot and cold extremes of their thermal niches, respectively. We show that cold-affiliated species growing outside and on the hotter portion of their thermal ranges decreased their growth. Warm-affiliated species can survive but reduce their growth under the colder portion of their thermal distribution. We demonstrate that growth responses are related to species’ thermal distributions; survival probability increased as species’ distribution optima were warmer than the experimental site and decreased as species’ distribution optima were colder than the study sites. These results can be explained by the negative effects of heat stress on simulated photosynthesis.  Our findings highlight the potential effects of rapid warming on the composition of highland forest species in this biodiversity hotspot.
Lake evaporation and its effects on basin evapotranspiration and lake water storage on the inner Tibetan Plateau
Authors: Wang Liuming , Wang Junxiao , Li Xingong
Published: February 2023

Lake evaporation (EW) is an important component of both basin evapotranspiration (ETB) and lake water balance for lake-basins on the inner Tibetan Plateau (IB), and it greatly influences lake water storage change (ΔSW). However, the effects of EW on ETB and ΔSW at lake-basin scale have never been reported for most basins on the IB. In this study, the EW of 117 large lakes (area > 50 km2) in 95 closed lake-basins (area > 1000 km2) were estimated, and its effects on ETB and ΔSW over 2001-2018 were examined using several newly derived diagnostic equations from the aspects of EW amount, rate, trend slope and inter-annual variability. During the study period, mean annual EW rate and total EW amount for the lakes are 994.25 ± 20.48 mm, and 24.83 ± 0.52 km3 respectively. The significant increasing trend (0.29 ± 0.04 km3/a) in annual EW amount is mainly caused by the increase (224.65 km2/a) in lake area (82.13%), and the increase (2.12 ± 1.28 mm/a) in EW rate is responsible for the rest (17.87%). EW accounts for 23.16% ± 4.94% of the ETB (107.24 ± 21.90 km3) for the 95 basins, and its impact has increased significantly (0.20% ± 0.09%/a) over the period. The increasing trends of EW rate and lake area ratio (0.06%, P < 0.05) contributed 14.49% and 52.69% to the increase trend in ETB (0.85 mm/a), and their variances contributed 1.60% ~ 4.79% and 1.64% ~ 6.50% to ETB variance (155.44 ± 107.97 mm2), respectively. The contribution of EW, quasi lake inflow (RL, 23.48 km3), and lake surface precipitation (PW, 9.18 km3) to mean ΔSW (7.82 km3) are -43.02%, 40.84% and 15.96%, respectively. And the increasing trends of the three components (EW, RL and PW) account for -58.02%, 29.59% and 12.39% of the decrease trend in annual ΔSW (-0.81 × 10 km3/a, P > 0.05), respectively. Basin RL, derived based on lake water balance, is significantly correlated with two independent land surface net precipitation estimates (0.57 < R < 0.86), and basin lake area ratio is a good indicator of basin EW and lake inflow in the IB.
Parameterising melt at the base of Antarctic ice shelves with a feedforward neural network
Authors: Burgard Clara , Jourdain Nicolas C. , Mathiot Pierre , Smith Robin
Published: February 2023

One of the largest sources of uncertainty when projecting the Antarctic contribution to sea-level rise is the ocean-induced melt at the base of Antarctic ice shelves. This is because resolving the ocean circulation and the ice-ocean interactions occurring in the cavity below the ice shelves is computationally expensive.Instead, for large ensembles and long-term projections of the ice-sheet evolution, ice-sheet models currently rely on parameterisations to link the ocean temperature and salinity in front of ice shelves to the melt at their base. However, current physics-based parameterisations struggle to accurately simulate basal melt patterns.As an alternative approach, we explore the potential use of a deep feedforward neural network as a basal melt parameterisation. To do so, we train a neural network to emulate basal melt rates simulated by highly-resolved circum-Antarctic ocean simulations. We explore the influence of different input variables and show that the neural network struggles to generalise to ice-shelf geometries unseen during training, while it generalises better on timesteps unseen during training. We also test the parameterisation on separate coupled ocean-ice simulations to assess the neural network’s performance on independent data.  
Changes in Arctic climate variability and extremes: effects on migratory birds
Authors: Skyllas Nomikos , Bintanja Richard
Published: February 2023

The climate is changing most rapidly in the Arctic because of Arctic amplification, influencing migratory bird species that depend on the short, but productive Arctic summer climate. A potential increase in climate variability can lead to reduced reproductive success and even be a major source of mortality for these birds. Most studies so far, focus on mean changes in climate, telling part of the story. However, along with changes in the mean, changes in the variability of climate will occur. These two combined (changes in mean and variability) can lead to more/less frequent extreme events such as heatwaves, droughts and excessive snowfall or melt.Here we focus on changes in variability and extremes of Arctic bird-related climatic variables, such as temperature, precipitation, snow cover, primary productivity, solar radiation, and soil moisture. We investigate how strongly these climatic variables vary on a daily, monthly, annual and decadal basis. Furthermore, we infer changes in variability between four distinct climate states (0.5x, 1x, 2x & 4x CO2 level): will the variability and probability for extreme events change in warmer or colder climates? How will this potentially affect Arctic migratory birds? For example, snowfall and ground snow cover are expected to decrease in a warmer climate, resulting in more areas available for nesting. However, snowfall variability is projected to increase, making conditions more unpredictable on an annual basis.To this end, we carried out four long (500 years), steady-state runs (constant CO2 level), using the state-of-the-art Earth System Model EC-Earth3. We used two versions of the model (EC-Earth3-Veg & EC-Earth3-CC) and 4 CO2 levels: 0.5x, 1x, 2x & 4x CO2 concentration of the year 2022. The end result is 4,000 years of model output data, allowing us to study climate-related changes in climate variability of Arctic bird-related variables.
Looking deep into the subducting Nazca plate under the Northern Chile forearc with local earthquake tomography
Authors: Hassan Nazia , Sippl Christian
Published: February 2023

Intermediate-depth earthquakes in many subduction zones occur in two distinct layers, forming an upper and a lower seismic zone separated vertically by an aseismic or weakly seismic region. This setting is widely known as Double Seismic Zone (DSZ). Notably, intermediate-depth seismicity in Northern Chile shows a pattern of intraslab seismicity which is distinct from the aforementioned conventional DSZ. Here, two parallel seismicity planes are present in the updip part of the slab, but at a depth of ∼80–90 km, there is a sharp transition to a highly seismogenic volume of 25–30 km thickness, which closes the gap between the two seismicity planes.While such an observation is unique to Northern Chile, understanding the processes behind the formation of this feature should provide important constraints on the mineral processes that govern seismicity in DSZs as well as the role and involvement of fluids. As seismic velocities contain important information about mineralogy and fluid content, we aim at a high-resolution characterization of the seismic wavespeeds of the Northern Chile subduction zone, mainly focusing on the subducting Nazca slab. Data from the seismic stations of the permanent IPOC (Integrated Plate boundary Observatory Chile) deployment in the Northern Chile forearc form the backbone of the dataset, but are complemented by several temporary deployments that span shorter time sequences as well. We use the seismicity catalog of Sippl et al. (2018) that contains >100,000 earthquakes and 1,200,404 P- and 688,904 S-phase picks for the years 2007 to 2014, and limit our analysis to events that have more than 14 P-arrivals as well as more than 7 S-arrivals. Constraining the hypocentral depth range to 40-155 km and the longitude range to 68° W- 72°W, we perform local earthquake tomography using the FMTOMO algorithm (Rawlinson et. al., 2006) with a dataset of 10102 events comprising 163,359 P- and 113,036 S- phase picks. We present first 3D models of P- and S-wavespeeds from the Northern Chile forearc between about 18.5° S and 24.5° S, as well as images of ray coverage, relocated seismicity and synthetic resolution tests. Tomography models for different choices of grid spacing and damping-smoothing parameters are compiled and compared in order to derive the optimal settings for the inversion. The presented seismic velocity distribution will eventually be compared with theoretical wavespeeds that are forward calculated assuming different mineralogical compositions in order to narrow the range of possible reactions that may be occurring at depth. 
Triaxial compression mechanical properties and multidirectional fracture mechanism of sandstone under different pore pressure
Authors: Fu Xiang , Ban Yuxin , Xie Qiang , Sun Weichen
Published: February 2023

After the impoundment of a high dam reservoir, the water pressure environment of the rock masses in dam base and reservoir bank changes, which may easily induce engineering problems such as bank slope instability and dam collapse. In order to investigate the differences and mechanisms of different constant water pressures on the rock mass of dam base, triaxial loading tests were conducted on sandstone with initial damage under different high constant porewater pressures, and the multidirectional fracture mechanism was analyzed by combining CT and electron scans. The test results show that:(1) Under the confining pressure of 80 MPa, the greater the pore water pressure, the more brittle the sandstone is, the lower the peak strength, the smaller the volume expansion stress, the pore water pressure increases from 10 MPa to 50 MPa, and the peak strength decreases by 33%.  (2) For different pore water pressure, there are significant differences in sandstone internal deterioration range and deterioration effect  as the fracture surfaces of sandstone specimens have various forms and directions. Due to CT scaning results, with the pore water pressure increases, the deterioration effect spreads from specimen middle to both ends. When the water pressure-confining pressure ratio is less than 25.0%, the deterioration of pore water pressure is mainly concentrated in the middle 1/3 of the specimen. When the water pressure-confining pressure ratio is bigger than 62.5%, the pore water pressure has obvious deterioration effect on the whole specimen. (3) Electron microscopy scanning reveals that with the increase of pore water pressure: the microgranular structure of sandstone changes from shear slip failure to shear fracture failure, and the microcrystalline structure of sandstone changes from cauliflower to rice granular. The macroscopic failure mode changes from plastic failure to brittle failure, and multidirectional fracture plane is formed, which is related to the migration of fine particles and the fracture of large particles in the meso-particle structure under pore water pressure. The formation of the multidirectional fracture plane is directly related to the shear strength of the microscopic crystal structure.
High-resolution satellite-based cloud detection for the analysis of land surface effects on boundary layer clouds
Authors: Fuchs Julia , Andersen Hendrik , Cermak Jan , Pauli Eva , Roebeling Rob
Published: February 2023

In this study, geostationary satellite observations are used to develop and validate two high-resolution cloud-masking approaches for the region of Paris to show and improve applicability for analyses of urban effects on clouds. Firstly, the Local Empirical Cloud Detection Approach (LECDA) uses an optimised threshold to separate the distribution of visible reflectances into cloudy and clear sky for each individual pixel accounting for its locally specific brightness. Secondly, the Regional Empirical Cloud Detection Approach (RECDA) uses visible reflectance thresholds that are independent of surface reflection at the observed location.Results show thatA decrease of cloud cover during typical fog or low-stratus conditions over the urban area of Paris for the month of November is likely a result of urban effects on cloud dissipation.
The regional approach, RECDA, is a more appropriate choice for the high-resolution satellite-based analysis of cloud cover modifications over different surface types than LECDA with regional biases of ±5 %.
This approach can provide comprehensive insights into spatiotemporal patterns of land-surface-driven modification of cloud occurrence and locally induced cloud processes, such as the diurnal variation of the occurrence of fog holes and cloud enhancements attributed to the impact of the urban heat island. Further, it is potentially transferable to other regions and temporal scales for analysing long-term natural and anthropogenic impacts of land cover changes on clouds.
An early warning decision support system for disease outbreaks in the livestock sector
Authors: Nassisi Paola , D'anca Alessandro , Mancini Marco , Santini Monia , Milanesi Marco , Caroli Cinzia , Aloisio Giovanni , Chillemi Giovanni , Valentini Riccardo , Negrini Riccardo , Ajmone Marsan Paolo
Published: February 2023

New climate regimes, variability and extreme events affect the livestock sector in many aspects, ranging from animal welfare, production, reproduction, diseases and their spread, feed quality and availability. Heat stress, especially when combined with excess or low humidity, exacerbates the perceived temperature or the drought conditions, respectively, increasing hazards for animals. Also, cold extremes, extraordinary windy conditions and altered radiation regimes are detrimental to both animals and fodder.In this context, the EU-funded SEBASTIEN project aims to provide stakeholders with a Decision Support System (DSS) for more efficient and sustainable management, and consequent valuation, of the livestock sector in Italy. SEBASTIEN DSS will integrate GIS, environmental and biological variables to generate updated risk maps for livestock diseases and zoonoses and their spread, alerting about the expected occurrence of stressing conditions for animals due to abiotic and biotic factors.The presence of parasites, vectors, and outbreaks will be combined with environmental data, gathered by spatially distributed meteorological and satellite monitoring, to detect conditions that can potentially favor or trigger the spread of related diseases. Sensor-based monitoring data will be integrated with the above information to determine ranges in animal parameters potentially associated with a higher risk of critical pathogen load or density of vectors potential carriers of diseases. Medium to long-term climate forecasts will support predicting possible shifts of favorable conditions that will open up new areas for parasites and pathogens. The vast amounts of data will be integrated and summarized into user-tailored information through a range of techniques, from empirical/statistical indicators to Machine Learning algorithms.
The primary porosity heterogenetic model of braided river sandstone reservoirs and its influence on the present porosity heterogeneity in the Kuqe depression, Tarim basin
Authors: Yiming Yan , Liqiang Zhang , Shuai Jiang , Zuotao Wang
Published: February 2023

Reservoir heterogeneity is one of the key geological problems in the process of oil and gas exploration and development of clastic rocks. Understanding reservoir heterogeneity is imperative to improve the effectiveness of exploration and development. The primary porosity calculation model proposed by the authors in the previous study is used to calculate the primary porosity of samples from modern braided river sands and sandstone outcrops of braided sand bodies, and the primary porosity heterogeneity (PPH) model of the braided sand body is established. The architectural-elemental structures of braided sand bodies have obvious control effects on the distribution of its primary porosity heterogeneity. The central braided channel and braid bars have strong primary physical properties; the primary porosity is high and always greater than 38%. The contact areas between the braided channel and braided bars have a low value of primary porosity and are always lesser than 33%. The distribution characteristics of the present porosity of braided river reservoirs are also influenced by sedimentary architecture. To compare the relationship between PPH, present porosity heterogeneity (pPH), and sedimentary architecture (SA), the images of PPH, pPH, and SA were digital, graying, and normalized. The digital image Q-Q plots of the distribution probability of PPH, pPH, and SA are calculated. The results show that: the Q-Q plots of the probability distribution of present porosity and architectural-elemental structures (or lithofacies) can reflect the influence and degree of primary porosity and diagenesis on the present heterogeneity of the reservoir. The Q-Q plots of distribution probability primary porosity and present porosity identify the distribution areas; the points are always distributed on different lines. The line ‘y = x’, is derived from compaction and primary porosity; the line ‘y = ax, a > 1’, is derived from diagenesis, which is unfavorable to the reservoir porosity preservation (such as cementation); the line ‘y = ax, a < 1’ is derived from diagenesis, which is beneficial to reservoir porosity preservation (such as dissolution). Based on the Q-Q plots of distribution probability, the influence from primary porosity and diagenesis can be quantitatively analyzed. The influence of primary porosity on pPH in braided sand bodies of Ahe formation (Kuqa depression), middle Jurassic fluvial sandstone (Datong basin), and Karamay Formation (Junggar basin) were 19%, 90%, and 10%, respectively. A quantitative probability distribution Q-Q model of reservoir PPH and pPH is effective for reservoir physical modeling.
From local to global: Community services in interdisciplinary research data management
Authors: Mehrtens Hela , Berndt Janine , Getzlaff Klaus , Lehmann Andreas , Lorenz Sören
Published: February 2023

GEOMAR research covers a unique range of physical, chemical, biological and geological ocean processes. The department Digital Research Services develops and provides advice and tools to support scientific data workflows, including metadata description of expeditions, model experiments, lab experiments, and samples. Our focus lies on standardized internal data exchange in large interdisciplinary scientific projects and citable data and software publications in discipline specific repositories to meet the FAIR principles. GEOMAR aims at providing their services not only internally but as a collaborative RDM platform for marine projects as a community service. How to achieve this on the operational level is currently worked on jointly with other research institutions in community projects, e.g. within the DAM (German Alliance of Marine Research), the DataHUB, an initiative of several research centres within the Helmholtz research area Earth and Environment, and within the national research infrastructure NFDI4Earth, a network of more than 60 partners.  Our latest use cases are the inclusion of the seismic data and numerical model simulations into the community portals to increase their visibility and reusability. We present the success stories and pitfalls of bringing a locally well established system in larger communities and address the challenges we are facing. 
Magnetotelluric image of a hyperextended and serpentinized rift system in the SW Barents Sea
Authors: Corseri Romain , Planke Sverre , Gelius Leiv Jacob , Faleide Jan Inge , Senger Kim
Published: February 2023

Magnetotellurics (MT) image the Earth’s electrical resistivity down to the mantle but is rarely used for investigation of offshore rifted margins. In such setting, the stretched lithosphere is altered by distinct tectono-thermal processes such as partial melt, hydration, or chemical alteration. However, lower crustal and upper mantle often display similar seismic velocities, density, and magnetic properties. Integration of resistivity models from MT data can lift this ambiguity in a hyper-extended rift system. In this project, we use an extensive marine MT database consisting of 337 receivers located along seven regional transects, emanating from ~70 000 km2 of 3-D CSEM surveys acquired for hydrocarbon exploration in the SW Barents Sea. 3D inversion of long period, marine MT data (1 – 3000 s) is performed on 104 receivers located along two, ~300 km long transects located over the Bjørnøya Basin, located ~300 km offshore northern Norway. We also apply 1D Bayesian inversion to a selection of receivers as an alternative to the deterministic approach for a more comprehensive exploration of the solution space.The resolving power of MT data is assessed with synthetic tests in an archetypal rift system where ample crustal thickness variation occurs. The results highlight that our MT data sense the transition from necking to hyper-extended domain where the crust (<~10 km) is not reconstructed by 3D inversion. In the Bjørnøya Basin – the northernmost member of a hyper-extended Cretaceous basin chain in the North Atlantic – seismic interpretation is used to assign a stratigraphic level to two prominent conductors in the resistivity models: (1) 0.1-1 Ω.m within Lower Cretaceous marine shales buried at 10-15 km depth (2) 1-10 Ω.m within the uppermost mantle. The bulk resistivity of a 2-phase, fluid-rock model emphasizes that seawater as a sole pore fluid phase is not conductive enough to explain the magnitude of the two conductors. A 25% serpentinization of mantle rocks can account for a fivefold rise in salinity of the residual fluid and is compatible with density and seismic velocities in the Bjørnøya Basin. Samples from fossil margins in the Alps and Pyrenes shows contamination of post-rift sediments pore fluids by mantle elements, highlighting the mobility of mantle-reacted fluids in hyper-extended systems. High-salinity fluid can ascend and mix with seawater in pore spaces of the sediments, supporting our proposed model of saline fluid circulation in hyper-extended basins.
Nightside dynamics influence on the dayside ionospheric current
Authors: Elhawary Reham , Laundal Karl Magnus , Reistad Jone Peter , Madelaire Michael , Ohma Anders
Published: February 2023

The main driver of the ionospheric dayside dynamics is the interaction between the interplanetary magnetic field (IMF) and the Earth’s magnetic field near the dayside magnetopause, while magnetotail activities control the nightside ionospheric dynamics. In spite of that, our knowledge about the influence of magnetotail activity on the dayside ionospheric dynamics and vice versa is limited. We investigate the nightside influence on the dayside ionospheric current by performing superposed epoch analyses of ground magnetic field data for northward IMF substorms. Such substorms encounter minimal influence of the dayside reconnection, granting an opportunity to isolate the effects of magnetotail activity on the dayside current system. Our analyses indicate that as nightside activity elevates, the dayside ionospheric current changes. We also find that lobe reconnection is weaker before substorm onset than what is expected for northward IMF conditions and then increases after onset, possibly due to reconfiguration of the magnetosphere. We present three possible mechanisms that can explain our observations.

 
Present and future flow simulation in a tailings pile at a former mine in France
Authors: L'hermite Pierre , Plagnes Valérie , Jost Anne , Reile Benoît , Blanc-Potard Isabelle , Regnier Damien , Descostes Michael
Published: February 2023

Water flow is an essential component of the long-term environmental management of former mine sites. Flow through tailings storage facilities (TSF) often generates chemical reactions and releases acidic water. In the case of static leaching, this acidification can last for multiple decades depending on the acid remaining in the tailings. This mining water is then collected and treated in treatment plants before it is released in the environment in compliance with environmental standards. The understanding of the current hydrogeological functioning of the TSF is essential to properly adapt water management today. Given the potential impact of climate change, simulation of future hydrogeological behaviour is also required to ensure sustainable water management over this century.We developed a daily time step model with HYDRUS 2D to represent the unsaturated hydrogeological functioning of a tailings pile of the former mine of Le Cellier (France). A granulometric analysis over the pile height provided reliable hydraulic properties and showed that the pile heterogeneity can be distributed into three layers. The historical monthly monitoring and the new daily hydrogeological monitoring implemented in 2021 measured the rainfall and discharges from the various drains that collect the water from the pile. As cross-correlations confirmed the fast reaction of drains discharges to rainfall (1 day), we simulated the water flow with the dual porosity package of HYDRUS. We also implemented the vegetation transpiration due to the presence of bushes and coniferous trees over the pile.The model performance was evaluated by comparing the observed (monthly and daily) discharges and the simulated one. The calibrated model reproduces correctly the annual discharges for the period 2014-2022 as well as the pile fast reaction to rainfall. To evaluate the climate change impacts on the hydrogeological functioning of the pile, we used as input of our calibrated model the daily precipitations and temperatures of the Coupled Model Intercomparison Project (CMIP5) for three climatic scenarios (RCP2.6, RCP4.5 and RCP8.5). The calculation of the Mann-Kendall trend test on the predicted water balance components leads to the conclusion that the effective rainfall should remain stable over the next 100 years. At the end of the century, the frequency of extreme events could increase by 50% and their intensity could rise by 9%. With the calibrated model, we simulated the discharges at the pile outlet and studied their annual changes as well as the pile response to extreme events under climate change. These simulations are essential to ensure an accurate water management for this century.
Energy transfer optimum in subaerial landslide impulse waves
Authors: Parvinashtiani AmirHossein , Abadie Stephane , El Omari Kamal , Le Guer Yves
Published: February 2023

Subaerial landslides can generate impulsive waves which, in turn, may cause significant damages to the facilities and people on the surrounding coasts. In spite of the numerous studies related to this complex phenomenon in the last decades, there is still a lot to understand, especially physically speaking.The present work aims at better understanding the energy transformation process from the slide initial potential energy to the final wave train energy. In particular, we would like to emphasize the existence of an optimum energy rate of transformation and investigate the reason for this existence.To do so, we rely on a Navier-Stokes two or three phases model (OpenFoam) and perform numerical experiments, fixing a few parameters (slope, density, rheology) and studying the effect of the others. The physics of the phenomenon is highly complex, involving liquid phases interaction, transient wave formation, nonlinear wave processes, dispersion, wave breaking, etc. Such a numerical model, despite its inherent uncertainty, is anyway able to provide a rich information, which may be later completed with experimental results. In particular, the model gives access to all the flow variables which allows to characterize in depth the energy processes. The free surface signal analysis is also valuable for wave celerity, and hence generation zone extent and dispersion analysis.In terms of research strategy, in order to restrict the complexity and allow a better understanding of the phenomenon, the idea is to start with a very simple rheology, the inviscid case, and progressively increase the numbers of rheological parameters (i.e., viscous flows, Bingham and finally Herschell Bulkley).During the conference, we will first illustrate the existence of an optimum in the rate of energy transformation for the inviscid slide by progressively increasing the slide volume. We will try to relate this optimum with the physical processes at stake (liquid mass interaction, wave breaking types, dispersion, etc.). Next, we will show the influence of the slide rheology in the process of energy transfer and in particular how the energy optimum varies with respect to the rheological parameters.  
Local moisture recycling across the globe
Authors: Theeuwen Jolanda , Staal Arie , Tuinenburg Obbe , Hamelers Bert , Dekker Stefan
Published: February 2023

Atmospheric moisture recycling describes how moisture evaporated from land precipitates over land. It explains how shifts in terrestrial evaporation due to land cover changes may affect precipitation and freshwater availability across scales. Recycling at regional and continental scales has been studied using different methods, such as offline and online moisture tracking models and bulk recycling models. Although recycling at regional and continental scales is relatively well understood, it has only recently become possible to study local moisture recycling across the globe. Recent developments in offline moisture tracking resulted in a dataset including a 10-year climatology (2008-2017) of atmospheric moisture connections from evaporation source to precipitation sink at a spatial scale of 0.5° (Tuinenburg et al., 2020). We used this data to calculate the local moisture recycling ratio, which we define as the fraction of evaporated moisture that precipitates within a distance of 0.5° (typically 50 km) from its source. Furthermore, we identify variables that correlate with the local moisture recycling ratio to assess its underlying processes. On average, 1.7% (st. dev. = 1.1%) of terrestrial evaporated moisture returns as local precipitation annually. However, there is large spatial and temporal variability with peak values over mountainous and wet regions and in summer. Wetness (i.e., precipitation and precipitation minus evaporation), orography, latitude, convective available potential energy, wind speed and total cloud cover have moderate to strong correlations with the local moisture recycling ratio. Interestingly, we find peaks in the local moisture recycling ratio at latitudes where air ascends due to the Hadley cell circulation (i.e., at 0° and 60°). These results suggest that wet regions characterized by ascending air and low wind speeds are favourable for high local moisture recycling ratios. This knowledge can be used to strategically recycle water using nature-based solutions or irrigation to minimize the usage of freshwater availability. For example, for the tropics and mountainous regions globally, and for the Mediterranean regions on the Northern Hemisphere, an increase in evaporation through for example, regreening has a relatively large contribution to local precipitation due to the relatively large local moisture recycling ratios here. These results suggest the potential to enhance freshwater availability with land cover changes, e.g., regreening. ReferencesTuinenburg, Obbe A., Jolanda J.E. Theeuwen, and Arie Staal. "High-resolution global atmospheric moisture connections from evaporation to precipitation." Earth System Science Data 12.4 (2020): 3177-3188.
Analysis of Early-Warning Signals for Arctic Summer Sea Ice Loss
Authors: Poltronieri Anna , Bochow Nils , Rypdal Martin
Published: February 2023

The rapid loss of Arctic Sea Ice (ASI) in the last decades is one of the most evident manifestations of anthropogenic climate change. A transition to an ice-free Arctic during summer would impact climate and ecosystems, both regionally and globally. The identification of Early-Warning Signals (EWSs) for the loss of the summer ASI could provide important insights into the state of the Arctic region.We collect and analyze CMIP6 model runs that reach ASI-free conditions (area below 106 km2) in September. Despite the high inter-model spread, with the range for the date of an ice-free summer spanning around 100 years, the evolution of the summer ASI area right before reaching ice-free conditions is strikingly similar across the CMIP6 models.When looking for EWSs for summer ASI loss, we observe a significant increase in the variance of the ASI area before reaching ice-free conditions. This behavior is detected in the majority of the models and also averaged over the ensemble. We find no increase in the 1-year-lag autocorrelation in model data, possibly due to the multiscale characteristics of climate variability, which can mask changes in serial correlations. However, in the satellite-inferred observations, increases in both variance and 1-year-lag autocorrelation have recently been revealed. 
Patterns and drivers of nutrient trends in flood-impacted surface waters: Insights from Bayesian modeling approaches
Authors: Fidan Emine , Emanuel Ryan , Reich Brian , Harris Angela , Nelson Natalie
Published: February 2023

Extreme events, including regional floods caused by hurricanes, have the potential to mobilize and transport nutrients across the landscape, creating public and environmental health concerns. Several studies have characterized the contaminants in floodwaters, but few studies offer insights into which watershed characteristics explain flood water quality signatures. To address lack of understanding on flood water quality descriptors, we aimed to explain floodwater nutrient concentrations as a function of different environmental variables. Specifically, we quantified nitrogen and phosphorus concentrations in floodwaters across the Atlantic Coastal Plain of North Carolina (USA) after Hurricane Florence, a major tropical storm that delivered up to 700 mm of rainfall to the region during September 2018. We also constructed a multivariate, spatial Bayesian model to explain nutrient responses as a function of different hydroclimatic factors, land use classifications, and nearby pollution point sources. Nutrient samples were collected at 51 different sites at four different time points spanning a year after Hurricane Florence impact: during major flood conditions and after floodwaters had receded. Samples were assessed for total Kjeldahl nitrogen, total ammonia nitrogen, nitrate and nitrites, total phosphorus, and orthophosphate. Results from this analysis show that nutrient concentrations were very low in floodwaters, with the exception of several sites that exhibited excessively high total Kjeldahl nitrogen, total phosphorus, and orthophosphate concentrations. Furthermore, modeling results indicate that swine production facilities (concentrated animal feeding operations; CAFOs), wastewater treatment plant (WWTP) proximity, and precipitation variables were important in explaining nutrient concentrations in floodwaters. This research suggests that swine CAFOs and WWTPs were likely sources of nutrient exports associated with Hurricane Florence, with rainfall amount being a primary driver. 
A Spatiotemporal hydrological response of extreme urban floods in Ha Noi – Vietnam.
Authors: Do Minh Ha , Corzo Perez Gerald , Barreto Wilmer , Zevenbergen Chris
Published: February 2023

Urban flood mostly is pluvial flood, caused by high rainfall intensities combined with the unsuitable drainage system and land cover. Because of the heterogeneous drainage system and the storm distribution dynamics, urban floods are rapid and spontaneous in space and time. Flood risk analysis was created to understand and assess the flood behavior, manage and mitigate the flood damage. However, flood risk assessments recently only have focused on the spatial distribution of the flood while temporal flood evolution in urban area is still an open question. This research aims to provide a spatio-temporal analysis of the urban flood by implementing the simplified model-based representation of flood evolution/development in space and time (spatiotemporal patterns) including time to flood the manhole, the location, spatial and temporal sequences of flood.To specify, 3 precipitation distribution patterns were collected from rainfall incidents in 2008, 2019, 2020, then extrapolated to create 21 scenarios following the return periods (i.e. 1.25-year, 2-year, 2.5-year, 5-year, 10-year, 20-year, 50-year). In each scenario, the dynamics of flood was estimated using the urban drainage system by SWMM5. Case study (Do Lo, Yen Nghia, Ha Dong, Ha Noi, Viet Nam) was divided into 115 sub-catchtments based on the Digital Elevation Model (DEM) and the drainage system map of this area. Land cover was created based on the LANDSAT images. Domestic waste water distribution was included in the model. The model is validated with the extreme events in 2020 and 2022.A spatio-temporal risk map was generated to show the flooding spatio-temporal sequences and non-flood region. Flood evolution on the time scale was shown in this map. The rate of flood change diagrams shows the flood responses from urban areas which vary from 1 to 107 mins in different scenarios.Rain gauge distribution sensitivity is examined under ranges of rain gauge distribution combinations in term of space and time.
Changes in the morphology of the step pool channels in the high-mountain ski resort without artificial snowmaking. An example from the Polish Tatra Mountains
Authors: Piątek Dawid , Gołąb Agata
Published: February 2023

The development and maintenance of ski resorts cause serious damage to the environment. Especially, the most severe changes can occur in the most sensitive environments such as high mountains, alpine ecosystem. The proper functioning of ski resorts based on some activities e.g. snow grooming, artificial snowmaking, and ski lifts conservation. This research we conducted in the only alpine ski resort in Poland, located in Kasprowy Wierch in the Tatra National Park in Tatra Mountains. Due to nature conservation law, the ski resort does not use artificial snowmaking. The main problems in this area are snow grooming and changes in the snow cover period. Snow groomers compact snow, which causes delay in spring thaws. Furthermore, in places where snow cover is thinner, snow groomers damage alpine vegetation and prepare conditions for soil erosion. Changes in snow cover, spring thaws, and water outflows intensify hillslope processes. It can lead to contact between hillslope and fluvial systems. The aim of this study is to recognize the influence of ski resort maintenance on the morphology of step-pool channels. We analyzed 4 step-pool channels: 2 are located within the area of ski runs and  2 on the hillslopes without ski runs. Drainage area, channel length, channel gradient, channel width, step height, step spacing, and particle size were analyzed. We measured 148 channel steps and 1,2 km of channels. The measured parameters were used in the statistical analyses: Pearson correlation and PCA. The results indicate that the step-pool channels within the area of ski runs are distinguished by a greater number of statistically significant relations typical of fluvial processes. The morphology of channels on the hillslopes without ski runs are dominated by relationships characterized as a typical effect of the hillslope processes. The results suggest that maintenance of ski resorts based on snow grooming and snow compaction can intensify fluvial processes in the step-pool channels in alpine environment, due to changes in snow melting patterns.This research is part of the project “Impact of skiing on high mountain catchment morphodynamic. An example from Kasprowy Wierch region, Polish Tatras” funded by the National Science Centre, Poland (Grant No. 2020/37/N/ST10/02550).