bluuebunny/crossref_metadata_2025 huggingface dataset:
Strain Localization at Volcanoes Undergoing Extension: Investigating Long-term Subsidence at Krafla and Askja in North Iceland
Authors: Lanzi Chiara , Sigmundsson Freysteinn , Geirsson Halldór , Maree Parks Michelle , Drouin Vincent
Published: February 2023

Localized ground deformation at volcanoes in extensional setting may occur because of strain localization. The magmatic system of a volcano with its liquid magma, magma mush, and hot crust will cause a rheological anomaly, where material properties may be very different from surrounding crust and mantle. Numerical models based on the Finite Element Method (FEM) are used to explore ground deformation at volcanoes in extensional environments, considering realistic volcano models with heterogeneous multi-layered structure, with both elastic and viscoelastic rheology. The effects of localized lateral and vertical variations in terms of geometry and material properties of the crust are explored, in a model domain undergoing stretching applied perpendicular to the lateral domain boundaries of one and two-layers model (at a rate of 17.4 mm/yr applied in our models). A one-layer model displays the same elastic feature throughout the whole domain except for a localized upper volume with lower elastic properties, compared to the surrounding crust, to simulate the shallow magmatic system. In a two-layer model, the top elastic layer overlies a viscoelastic layer that locally reaches shallower levels to symbolize the deep magmatic system beneath the shallow low-rigidity volume previously introduced. A localized surface subsidence signal is a characteristic feature of magmatic system with a large body of localized viscoelastic rheology at shallow depth. The subsidence signal is strongly dependent on the viscosity and volume of the up-doming viscoelastic material. A model with viscosity of 5 × 1019 Pa s in the up-doming material, and a 7 – 15 km-thick elastic layer, show a small subsidence rate, ~0.1 – 0.4 mm/yr. Our models show an increase of the localized subsidence rate, from 1.9 to 5.5 mm/yr, as the viscosity decreases from 1018 Pa s to 1016 Pa s in the up-doming material. Lower viscosities (<1016 Pa s) show no further change in subsidence rate when compared to the 1016 Pa s solution. We apply three-dimensional FEM models to improve understanding of the subsidence at the Krafla and Askja volcanic systems (1989-2018 and 1983-2018, respectively) in the Northern Volcanic Zone of Iceland. The two subsiding areas (roughly 9 × 10 km each) lie in about 50 km-wide zone which marks the North America-Eurasia divergent plate boundary. The rate of subsidence at Krafla was ~1.3 cm/yr in 1993-2000 and slowed down to 3-5 mm/yr in 2006-2015. The rate of subsidence at Askja decayed more slowly than Krafla. During the 1983-1998 the subsidence rate was ~5 cm/yr; in 2000-2009, geodetic monitoring showed that the subsidence slowed down to ~2.5 cm/yr. Comparison of FEM models to geodetic data in North Iceland suggests that plate divergence processes may account for part of the observed subsidence, dependent on how extensive rheological anomalies in relation to magma are beneath the volcanoes.
Regional surface climate irreversibility under temperature overshoot scenarios
Authors: Steinert Norman Julius , Schwinger Jörg , Lee Hanna
Published: February 2023

With the current rate of climate change, exceeding the remaining global carbon budget for a warming target of 1.5 °C becomes increasingly likely. Hence, attention has been put towards carbon dioxide removal (CDR) strategies that, given the required socio-economic feasibility and sustainability, allow temporary emission overshoots. The balance between the potential viability of overshoot scenarios and the associated risks depends on their characteristics and how the global ecosystems respond during and after the overshoot. Here we investigate the global climate and regional ecosystem responses to emission-driven overshoot scenarios of different magnitude, duration and timing, imposing the potential for irreversible changes. Our analysis focuses on the behavior and reversibility of thermodynamic, hydrological, and biogeochemical processes and their impacts on a regional scale. Based on results from state-of-the-art Earth system models, physically driven mechanisms appear to be mostly reversible for moderate overshoot scenarios considering a response lag in the range of decades. However, feedbacks in high overshoot scenarios and biogeochemical processes show signs of irreversibility on a larger spatial scale – some of which have been brought into connection with the crossing of tipping points for certain elements of the Earth system. Our analysis informs about the reversibility of climate system processes, which allows refining thresholds for global climate change mitigation policies. Furthermore, the aspect of partial reversibility of temperature overshoot scenarios might not be the main concern, but rather the impacts and risks occurring during the periods of elevated temperatures during the overshoot.
A Study on the Effect of Target Orientation on the GPR Detection of Tree Roots Using a Deep Learning Approach
Authors: Lantini Livia , Massimi Federica , Sotoudeh Saeed , Mortimer Dale , Benedetto Francesco , Tosti Fabio
Published: February 2023

Monitoring and protection of natural resources have grown increasingly important in recent years, since the effect of emerging illnesses has caused serious concerns among environmentalists and communities. In this regard, tree roots are one of the most crucial and fragile plant organs, as well as one of the most difficult to assess [1].Within this context, ground penetrating radar (GPR) applications have shown to be precise and effective for investigating and mapping tree roots [2]. Furthermore, in order to overcome limitations arising from natural soil heterogeneity, a recent study has proven the feasibility of deep learning image-based detection and classification methods applied to the GPR investigation of tree roots [3].The present research proposes an analysis of the effect of root orientation on the GPR detection of tree root systems. To this end, a dedicated survey methodology was developed for compilation of a database of isolated roots. A set of GPR data was collected with different incidence angles with respect to each investigated root. The GPR signal is then processed in both temporal and frequency domains to filter out existing noise-related information and obtain spectrograms (i.e. a visual representation of a signal's frequency spectrum relative to time). Subsequently, an image-based deep learning framework is implemented, and its performance in recognising outputs with different incidence angles is compared to traditional machine learning classifiers. The preliminary results of this research demonstrate the potential of the proposed approach and pave the way for the use of novel ways to enhance the interpretation of tree root systems. AcknowledgementsThe Authors would like to express their sincere thanks and gratitude to the following trusts, charities, organisations and individuals for their generosity in supporting this project: Lord Faringdon Charitable Trust, The Schroder Foundation, Cazenove Charitable Trust, Ernest Cook Trust, Sir Henry Keswick, Ian Bond, P. F. Charitable Trust, Prospect Investment Management Limited, The Adrian Swire Charitable Trust, The John Swire 1989 Charitable Trust, The Sackler Trust, The Tanlaw Foundation, and The Wyfold Charitable Trust. The Authors would also like to thank the Ealing Council and the Walpole Park for facilitating this research. References[1] Innes, J. L., 1993. Forest health: its assessment and status. CAB International.[2] Lantini, L., Tosti, F., Giannakis, I., Zou, L., Benedetto, A. and Alani, A. M., 2020. "An Enhanced Data Processing Framework for Mapping Tree Root Systems Using Ground Penetrating Radar," Remote Sensing 12(20), 3417.[3] Lantini, L., Massimi, F., Tosti, F., Alani, A. M. and Benedetto, F. "A Deep Learning Approach for Tree Root Detection using GPR Spectrogram Imagery," 2022 45th International Conference on Telecommunications and Signal Processing (TSP), 2022, pp. 391-394.
State-of-the-art of the Pyrenean Paleomagnetic Database
Authors: Pueyo Emilio L. , Silva-Casal Roi , García-Lasanta Cristina , López-Mir Berta , Elger Kirsten , Pedrera Antonio , García-Senz Jesus
Published: February 2023

The Pyrenees display numerous paleomagnetic studies acquired during the past six decades after the pioneer works carried out by the University of Utrecht in the early sixties (Van der Voo, 1969 and references therein). Currently, the Pyrenean Paleomagnetic Database (of IGME) includes nearly 40,000 individual vectors (demagnetizations) from more than 3000 sampling sites and more than 170 magnetostratigraphic profiles (comprising more than 35 kilometres of sections) that are harmonized and synthesized. This implies a significant increase (ca. 20%) with respect to previous versions introduced in the Iberian paleomagnetic meeting in 2017. This outstanding amount of data (considering the rather small size of the Pyrenees) is due to: 1) excellent outcrop conditions of stratigraphic sequences and biostratigraphic calibrations with global interest; 2) the availability of synorogenic materials, allowing for an accurate dating of deformation processes; and 3) the occurrence of well-exposed areas affected by lateral transference of deformation (oblique structures) that have motivated abundant paleomagnetic studies focused on characterizing vertical-axis rotations.In this work we present the state of the art of the Pyrenean Paleomagnetic Database. About 75% of the compiled paleomagnetic data display fisherian means with alfa95 below 15° (84% below 20°) that are in agreement to standard reliability criteria of paleomagnetic data in tectonic studies. Most sites and localities are drilled in Cenozoic (Miocene to Paleocene) and Upper Cretaceous rocks, thus, coeval or younger than the Pyrenean convergence time. Sites in Lower Cretaceous and Jurassic rocks represent pre-orogenic stages and are coeval or older than the rotation of Iberia (Biscay Bay opening). Less than 15% of the paleomagnetic sites come from Triassic and Permian red-beds and display an uneven distribution along the mountain chain. A similar uneven distribution of sites is observed in Paleozoic rocks. Several studies have determined remagnetization processes in the Pyrenees from the Western Basque Palaeozoic massifs to other Palaeozoic rocks of the Axial Zone mostly in relation to burial processes. This is the case of Lower Cretaceous, highly subsiding basins, like Organyá, Mauléon, Cotiella or the Chaînons Béarnais, as well as other Ceno-Mesozoic sequences in the Internal Sierras and related units; Larra-Monte Perdido, Nogueras, Boixols, Cadí, etc. In most cases, the remagnetization ages are Cenozoic when maximum temperatures were acquired at the base of the sequences during the convergence period or, in any case, younger than the rotation of Iberia and the opening of the Biscay Bay. Van der Voo, R. (1969). Paleomagnetic evidence for the rotation of the Iberian Peninsula. Tectonophysics, 7(1), 5-56.
Multimodel comparison of weathering fluxes during the last deglaciation
Authors: Lhardy Fanny , Liu Bo , Willeit Matteo , Bouttes Nathaelle , Kurahashi-Nakamura Takasumi , Hagemann Stefan , Ilyina Tatiana
Published: February 2023

The global carbon cycle is a complex system with many drivers, including slow ones such as the chemical weathering of rocks. At long enough timescales, changes in weathering rates influence CO2 consumption, but also the river loads of carbon, nutrients, and alkalinity. In particular, the global ocean inventory of alkalinity is a critical driver of carbon sequestration into the ocean. Thus, any transitory imbalance between the sources and sinks of alkalinity can lead to changes in ocean chemistry and impact atmospheric CO2 concentration. During the last deglaciation (ca. 19-11 ka BP), the Earth’s climate transitioned from cold and arid to comparatively warmer and wetter conditions. Simultaneously, large ice sheets melted and led to a significant rise of sea level (ca. +120 m), which reduced the size of the exposed continental shelves. Loess deposits were also gradually eroded. These changes logically influenced the chemical weathering of rocks because weathering rates depend on climate variables (runoff and temperature), land-sea distribution and lithology. Some modelling studies and proxy reconstructions suggest little net changes over this period. Yet, the deglacial changes of weathering rates remain poorly constrained.Most Earth System Models do not explicitly represent weathering and the consequent river fluxes. Moreover, the alkalinity inventory is often assumed constant in models, despite the fact that proxy data suggest an elevated total alkalinity at the Last Glacial Maximum (and the likely changes of its sources and sinks). These choices can potentially bias the model representation of the global carbon cycle, whose deglacial variations have been notoriously hard to simulate for decades. In this study, we calculate weathering fluxes of phosphorus and alkalinity (among others) using reconstructed lithological maps, and model results from transient runs of the last deglaciation and/or time-slice runs of the Last Glacial Maximum and pre-industrial period. To improve robustness, we compare the evolution and spatial distribution of weathering fluxes in different models. We demonstrate that while the increase of runoff during deglaciation enhances weathering, the rise of sea level and the erosion of loess deposits tend to have a counterbalancing effect on the river loads. Our model ensemble tends to show inconsistent deglacial changes of some river loads (e.g. for phosphorus), depending both on runoff biases and on the representation of land-sea distribution. Still, all models indicate a significant decrease of river alkalinity from the LGM to the pre-industrial. Using these findings, we discuss the implications of an explicit representation of weathering fluxes for the global carbon cycle in transient runs with Earth System Models.
Future Heliospheric System Science Exploration in Japan
Authors: Saito Yoshifumi , Miyoshi Yoshizumi , Seki Kanako , Imada Shinsuke
Published: February 2023

Toward the inner Heliospheric system science exploration in the late 2020s, ISAS/JAXA is currently operating the Arase, BepiColombo/Mio, Hinode, and Akatsuki satellites, and Solar-C EUVST is scheduled for launch in the near future. These missions will be linked together with other satellite missions such as Solar-Orbiter, Solar Parker Probe, Cluster, THEMIS, MMS etc. to realize exploration of the inner Heliosphere with unprecedented scale.In the early 2030s, Japanese Solar Terrestrial Physics group is considering the FACTORS formation-flight satellite mission in order to reveal the energy coupling mechanisms and mass transport between the space and Earth’s atmosphere. In the late 2030s, another formation-flight magnetospheric satellite mission the science target of which includes understanding the cross-scale / cross-region coupling is also under consideration hopefully on orbit at the same time with European future mission Plasma Observatory. These future missions will closely collaborate with NASA’s future GDC and Magnetospheric Constellation missions.The future Heliospheric system science exploration will be conducted by multiple satellite missions further expanding their observation area while improving the quality of each individual satellite mission. Japanese Solar Terrestrial Physics group will conduct in-situ observation of space plasmas with MMX (Martian Moons Exploration) and MIM(Mars Ice Mapper) in the Martian system and with JUICE (Jupiter Icy Moons Explorer) in the Jovian system. Collaboration between Japanese Solar Physics and Solar Terrestrial Physics groups for considering the future out-of-ecliptic-plane mission is also about to start.In order to realize the future Heliospheric system science exploration, significant technological development is mandatory. Current status of the technological development in Japan for enabling the future Heliospheric system science exploration will also be presented.
Crustal fluid migration and gas-water-rock interaction processes in a seismic area: the case study of the Contursi hydrothermal system (Southern Appenines)
Authors: Buttitta Dario , Capasso Giorgio , Paternoster Michele , Barberio Marino Domenico , Gori Francesca , Petitta Marco , Picozzi Matteo , Caracausi Antonio
Published: February 2023

The geochemical characteristics of fluids that emerge at the Earth's surface are influenced by gas-rock-water interactions in the deep and shallow crustal layers, including mixing, outgassing of volatiles, and precipitation of minerals. The goal of the study was to understand the various interactions that influence the migration and behaviour of fluids within the Earth's crust and how they may change during the process of crustal fluid migration towards a hydrothermal system in the shallow crustal layers and within (Contursi basin, Italy). These processes can make it difficult to identify the source of deep gas by using the classical approach based on mixing processes of fluids and carbonate dissolution. Therefore, alternately the relationship between Total Dissolved Inorganic Carbon (TDIC) and the δ13CTDIC in groundwater from the Contursi hydrothermal system investigating the water-gas-rock interaction at the local scale through the detailed reconstructions of the geological framework at depth have been taken into consideration. We found that both the dissolved and free gas in the hydrothermal system probably originated from a deep CO2 endmember with a δ13CCO2 value ranging from +2.12‰ to +3.20‰ (PDB) depending on the presence of brine or freshwater in the local aquifers. However, we observed that this CO2 lost its pristine carbon isotopic signature during its storage in the deep dolomite-composed reservoirs (6-8 km), making it challenging to figure out its deep origin (decarbonation vs mantle/magmatic CO2). Our calculations also showed that the output of CO2, taking into account secondary processes (i.e. degassing CO2 and calcite precipitation) and interactions with water at different salt concentrations, could be at least 40% higher than estimates from the mixing-only approach, such that it is comparable with several active and quiescent worldwide volcanic systems. In order to interpret potential geochemical changes that may occur during future seismic events in sites like Contursi, which are earthquake-prone areas, it is necessary to implement models that can help us understand fluids origin and the processes that influence their chemical and isotopic signature.
Evaluating the feasibility and performance of Nature-based Solutions in Can Tho, Vietnam
Authors: Jiang Jinghua , Liang Qiuhua
Published: February 2023

Can Tho, the largest city in the Mekong River Delta, is experiencing rapid urbanisation that is causing many typical urbanisation-related issues, including the increasing flood risk. The flooding area has expanded from 30% to 50% of the total city area due to urbanisation and climate change. Due to the low topography and poor capacity of drainage systems, the city may sometimes remain inundated for up to three hours after the rain event has ended. It is essential to develop effective and also sustainable management strategies for the city to mitigate risk of flooding, especially surface water flooding caused by extreme heavy rainfall.Nature-based Solutions (NbS) are proposed and widely promoted globally as a sustainable strategy for managing flood risk and creating other benefits. For flood risk management, NbS can help a city reduce surface runoff and subsequently release pressure on drainage systems through infiltration and interception, thus mitigating flood risk. Numerical modelling has been widely used to support the design and assessment of NbS. Conventionally, NbS modelling is achieved by integrating a hydrological model with NbS simulation modules though a one-way coupling method. Such models are incapable of fully describing the rainfall-runoff-flooding processes dynamically interacting with NbS measures, and therefore can only provide limited information such as temporal and spatial variation of runoff removal rate for NbS design and evaluation.In this work, a 2D hydrodynamic flood model is adopted and further developed by coupling with compatible NbS simulation approaches to overcome the existing NbS restrictions. The new modelling framework is applied in Can Tho city to evaluate the feasibility and performance of different NbS against various evaluating metrics. The simulation results indicate that green roofs, rain gardens, and bio-retention cells can effectively reduce inundation area, flow rate, and runoff volume to protect localised infrastructure and key buildings under certain rainfall scenarios. However, dramatic change of flow velocities is observed near the key infrastructure and structures following the implementation of a rain garden, posing higher risk to pedestrians and vehicles. In-depth analysis of the hydrological performance of bio-retention cells further indicates that their designed capacity is not sufficiently exploited due to the inappropriate installation location, further demonstrating the advantage of the proposed model for better planning and design of NbS to achieve optimised performance.
Time-varying sensitivity analysis across different hydrological model structures, variables and time scales
Authors: Guse Björn , Herzog Anna , Thober Stephan , Spieler Diana , Melsen Lieke , Kiesel Jens , Staudinger Maria , Wagner Paul , Loritz Ralf , Müller Sebastian , Stölzle Michael , Scholz Larissa , Berg Justine , Pilz Tobias , Ehret Uwe , Düthmann Doris , Houska Tobias , Pool Sandra , Tarasova Larisa ,   other members of the DFG Scientific network IMPRO
Published: February 2023

Temporal sensitivity analyses can be used to detect dominant model parameters at different time steps (e.g. daily or monthly) providing insights on their temporal patterns and reflecting the temporal variability in dominant hydrological processes. However, hydrological processes do not only vary in time under different hydrometeorological conditions, but also the time scales of implemented processes are different. Here, the impact of different time scales (e.g. daily vs. monthly) on sensitivity patterns is investigated.A temporal parameter sensitivity analysis is applied to three hydrological models (HBV, mHM and SWAT) for nine catchments in Germany. These catchments represent the variability of landscapes in Germany and are dominated by different runoff generation processes. In addition to discharge, further model fluxes and states such as evapotranspiration or soil moisture are used as target variables for the sensitivity analysis.To analyse the impact of different time scales, two approaches are compared. In a first approach, daily simulated time series are used for the sensitivity analysis and aggregated then to monthly averaged sensitivities (Post-Agg). In a second approach, the simulated time series is first aggregated to a monthly time series and than used as input for the sensitivity analysis (Pre-Agg).Our analysis shows that monthly averaged sensitivity patterns of different model outputs vary between Post- and Pre-Aggregation approach. Model parameters that are related to fast-reacting runoff processes, e.g. surface runoff or fast subsurface flow, are more sensitive when using daily time series for the sensitivity analysis (Post-Agg). In contrast, model parameters related processes with longer time scales such as snowmelt or evapotranspiration are more emphasized in monthly time series (Pre-Agg). These differences in the sensitivity results between Post-Agg and Pre-Agg are in particularly pronounced when using the integrated value of discharge as the target variable. Instead, the differences are smaller when applying the sensitivity analysis directly to represent model fluxes.Moreover, our analysis shows changes in dominant parameters along a north-south gradient which can be explained by the physiographic characteristics of the catchments. The differences in the sensitivity results between the models can be related to the different model structures.Based on our analysis, we recommend to either using model outputs of the major hydrological variables or different time scales for the sensitivity analysis to derive the maximum information from the diagnostic model analysis and to understand how model parameters describe hydrological systems.
Heliospheric Science From Gateway With HERMES 
Authors: Paterson William R. , Gershman Daniel J. , Kanekal Shrikanth G. , Livi Roberto , Moldwin Mark B. , Zesta Eftyhia , Randol Brent , Samara Marilia
Published: February 2023

The Heliophysics Environmental and Radiation Measurement Experiment Suite (HERMES) is a multi-instrument science payload that will attach to the HALO module of the Artemis Program’s Gateway lunar outpost.  HERMES instrumentation includes an electron electrostatic analyzer, an ion mass spectrometer, a proton and electron telescope for energetic particles, and a set of magnetometers. After Gateway arrives in its polar lunar orbit, HERMES will conduct a science campaign that addresses objectives in heliospheric and magnetospheric physics.  Analysis of the in-situ measurements from HERMES will leverage observations from other space missions.  Of note are the 2 THEMIS/ARTEMIS probes already in lunar orbit.  They provide measurements of particles and fields that can be compared directly with those from HERMES.  With this small constellation of spacecraft it will be possible to analyze structures in the solar wind, such as CMEs and SIRs, on scales ~11 Earth radii (70,000 km).  HERMES also serves as a pathfinder for future space-weather payloads as may be carried on deep-space missions of exploration for which local measurements of space-weather can contribute to accuracy of predictions and thereby contribute to crew safety. The HERMES science teams will share data and work closely with scientists from ESA’s European Radiation Sensors Array (ERSA) and with those of the joint ESA/JAXA Internal Dosimeter Array (IDA). HERMES data at all levels will be fully open and accessible through NASA's Space Physics Data Facility to enable independent analyses.  In this presentation we provide an overview of science plans, including expectations for collaboration with international partners and with other science missions. 
Imaging small-scale ocean dynamics at interfaces of the Earth System with the SeaSTAR Earth Explorer 11 mission candidate
Authors: Gommenginger Christine , Martin Adrien C. H. , McCann David L. , Egido Alejandro , Hall Kevin , Martin-Iglesias Petronilo , Casal Tânia
Published: February 2023

SeaSTAR is a satellite mission candidate for ESA Earth Explorer 11 that proposes to measure small-scale ocean dynamics below 10 km at ocean/atmosphere/land/ice interfaces of the Earth System. SeaSTAR products consist of high-resolution images of total surface current vectors and wind vectors of unprecedented resolution (1 km) and accuracy over a wide swath. A key objective of SeaSTAR is to characterize, for the first time, the magnitude, spatial structure, regional distribution and temporal variability of upper ocean dynamics on daily, seasonal and multi-annual time scales, with particular focus on coastal seas, shelf seas and Marginal Ice Zone boundaries. The mission addresses an urgent need for new measurements of small-scale ocean processes to help understand and model their impacts on air-sea interactions, horizontal water pathways, vertical mixing and marine productivity. High-resolution imaging of total currents with collocated wind and waves data would bring new means of validating and developing models to improve operational forecasts and climate projections. The presentation will outline the key elements of the mission and the latest status of the mission concept evolution, with the technical solutions and trade-offs that are being considered. We will also present the latest results of the SEASTARex airborne campaign in Iroise Sea using the OSCAR (Ocean Surface Current Airborne Radar) demonstrator.
Dissolving better: what can Earth System models learn from 60 years of in situ carbonate mineral dissolution measurements
Authors: Cala Ben , Sulpis Olivier , Wolthers Mariette , Humphreys Matthew
Published: February 2023

Carbonate mineral dissolution has the potential to neutralise anthropogenic CO2 and act as a buffer against ocean acidification. To accurately quantify these effects and predict how this process will respond to a changing climate, we need to know what its drivers are. Still, our current understanding of dissolution is incomplete: for instance, excess alkalinity production in the mesopelagic suggests that carbonates dissolve where seawater is thought to be supersaturated with respect to calcite. In situ measurements of the dissolution rate can help to determine which other environmental factors - apart from the saturation state - drive dissolution. However, those measurements are scarce and even though they measure the same phenomenon, the resulting rates differ by up to two magnitudes between the available studies. Additionally, the dissolution patterns with depth are also not consistent with each other. Possible explanations for these variances include differences in methodologies and sample types, or the respective physical and chemical environments. This work aims to disentangle those factors and determine the real qualitative and quantitative value of the existing datasets. This is achieved through review of the literature and the training and interpretation of a supervised regression model (XGBoost), exploring the blind spots in our current conception of carbonate mineral dissolution. Based on these results, changes to the implementation of calcite and aragonite dissolution in Earth System Models are recommended.
Digital mapping of soil properties with optimally scaled predictors
Authors: Dornik Andrei , Cheţan Marinela Adriana , Drăguţ Lucian , Iliuţă Andrei , Dicu Daniel Dorin
Published: February 2023

Although improved and more effective approaches for predicting the spatial distribution of soils have long been developed, further study in this field is still required. This study proposes an algorithm for generating terrain attributes over several scales and automatically selecting the optimal scale for each predictor using the powerful Random Forests (RF) method, to increase the accuracy of soil property maps. The effectiveness of using optimal scaled predictors to improve the accuracy of soil maps is investigated on nine soil properties (clay, silt, and sand content within the 0-20 cm range, soil porosity within the 0-20 cm range, subsoil porosity, pH within the 0-20 cm range, edaphic volume, humus reserve, and base saturation within the 0-20 cm range). Experiments were carried out in two study areas in western Romania, located along the boundary between the Western Plain and the Western Hills. The first study area contains 96 georeferenced soil profiles, while the second has 92. The initial 12.5 m digital elevation model (DEM) was resampled to 25 m, then in 25 m increments to 1000 m, resulting in 40 coarser versions of the DEM. Each rescaled version of the DEM was used to derive 10 terrain attributes, resulting in 40 rescaled versions of each terrain attribute. Next, a Random Forest (RF) and a linear correlation model with each scaled terrain attribute were created using soil property values. The highest R-squared value and correlation coefficient, respectively, are used by the script to produce two sets of optimally scaled terrain attributes. All multiscale predictors, optimally scaled predictors based on the RF model, optimally scaled predictors based on the correlation coefficient, and original not scaled predictors were the four groups of predictors used to map each soil attribute. The results showed that when the predictors are optimally scaled compared to maps produced with the original unscaled predictors or with all multiscale predictors, more accurate and less uncertain soil property maps are obtained.
Sinuous Aurora at Mars: exploring a new phenomenon with data and models
Authors: Lillis Robert , Azari Abigail , Ma Yingjuan , Chirakkil Krishnaprasad , Deighan Justin , Chaffin Michael , Jain Sonal , Holsclaw Gregory , Brain David , Al Matroushi Hessa , England Scott , Schneider Nick , Xu Shaosui , Al Mazmi Hoor , Halekas Jasper , Ramstad Robin , Espley Jared , Gruesbeck Jacob , Curry Shannon
Published: February 2023

Benefiting from a large orbit and high sensitivity, the Emirates Mars mission EMUS instrument has provided the first opportunity to regularly image Mars’ discrete FUV aurora synoptically.  EMUS has collected nearly 1000 synoptic observations of the Mars nightside have revealed at least three distinct types of discrete Aurora: 1) crustal field aurora, appearing in regions of mostly radial crustal magnetic fields, 2) patchy discrete aurora, observed away from strong crustal fields, and 3) sinuous discrete aurora, extending from the terminator typically thousands of kilometers onto the nightside, away from crustal fields.Sinuous Discrete Aurora (SDA) is observed in approximately 5% of observations and is characterized by 2 primary attributes: morphology and the local time of its intersection with the terminator. Morphologies include serpentine, approximately linear, and short/lumpy. Dusk-side SDA does not occur preferentially for any particular interplanetary magnetic field (IMF) orientation, while Dawn and Midnight SDA appear to show a preference for northeastward IMF directions measured in situ by the MAVEN spacecraft. Dusk SDA observed about twice as often as Dawn or Midnight SDA. SDA reflect conditions whereby particular magnetic topologies connect the nightside atmosphere to a source of abundant electrons, whether dayside photoelectrons or sufficiently energetic magnetotail/sheath electrons.  In particular, midnight sinuous discrete aurora appear to be a projection of the tail current sheet, a persistent but highly variable feature of Mars’ double-lobed magnetotail resulting from the draping of the IMF around the conducting obstacle of Mars’ dayside ionosphere.  This interpretation is supported by magnetohydrodynamic (MHD) simulations, showing that the orientation of the tail current sheet approximately matches the orientation of midnight SDA.EMM EMUS promises to be an invaluable tool in helping to understand the drivers of Martian Aurora.
X-shooter-based climatologies of intensity, solar cycle effect, and residual variability for 298 OH lines
Authors: Noll Stefan , Schmidt Carsten , Kausch Wolfgang , Bittner Michael , Kimeswenger Stefan
Published: February 2023

The line emission from the various roto-vibrational bands of the OH radical is an important tracer of the chemistry and dynamics in the Earth's nocturnal mesopause region between about 80 and 100 km. As most studies have focused either on a few bright lines or integrated emission from relatively wide wavelength windows, there is still a lack of knowledge with respect to the variability of faint lines from high rotational levels as well as the change of the variability patterns depending on the line parameters, which influence the effective emission height. Thanks to a large data set of about 90,000 near-infrared X-shooter spectra taken at Cerro Paranal in Chile within a time interval of 10 years, we have been able to derive line-specific climatologies of intensity, solar cycle effect, and residual variability for local time and day of year based on a set of 298 OH lines. Our analysis of the derived climatologies involves different decomposition techniques, the study of the variance depending on the time scale of the perturbation, and the calculation of correlations for the line dependence of different properties. The considered effective line emission heights originate from the investigation of the propagation of a strong quasi-2-day wave in 2017 using the X-shooter and space-based SABER data. Our results for the entire X-shooter data set reveal the importance of the mixing of thermalised and non-thermalised rotational populations for the amplitude of a perturbation as well as a shift of the climatological variability patterns with local time depending on the emission height. The latter implies a strong influence of the migrating diurnal tide and causes significant line-dependent differences in the effective solar cycle effect, which mainly depends on the solar forcing in the austral winter.
Representation of Precipitation Phases and a New Parameterization for Below-Cloud Scavenging in Regional Air Quality modelling
Authors: Ghahreman Roya , Gong Wanmin , Makar Paul , Lupu Alexandru , Cole Amanda , Banwait Kulbir , Lee Colin , Akingunola Ayodeji
Published: February 2023

Below-cloud scavenging is the process of aerosol removal from the atmosphere between cloud-base and the ground by precipitation (e.g. rain or snow), and affects aerosol number/mass concentrations, lifetime and distributions. An accurate representation of precipitation phases is important in treating below-cloud scavenging as the efficiency of aerosol scavenging differs significantly between liquid and solid precipitation. To study cloud processes and precipitation chemistry, we examined representation of below-cloud aerosol scavenging of in the current GEM-MACH model, including a revised approach in precipitation phase partitioning and implementing a new aerosol below-cloud scavenging scheme (from Wang et al., 2014) and comparing with the GEM-MACH’s existing scavenging scheme, based on Slinn (1984). 
Overall, the multi-phase partitioning and Wang et al. (2014) scavenging scheme improve GEM-MACH performance as compared with observations. Including multi-phase approach leads to a decrease on SO42- scavenging and impacts the below-cloud scavenging of SO2 into the aqueous phase. The impact of the new scheme on wet deposition of NO3- and NH4+ varies, with both increases and decreases in wet scavenging, and is more important at specific cloud locations. The two aerosol scavenging rates differ during liquid precipitation in the 0.1-1 µm size range mostly at high precipitation intensity. The two aerosol scavenging schemes diverge for aerosols smaller than 1 µm for solid precipitation at lower intensity (R=0.01 mm/h), while at higher precipitation intensities (R=10 mm/h), the two schemes show larger differences for aerosols larger than 1 µm. The changes on the speciated particles (sulphate, nitrate and ammonium) are consistent with the changes in the wet scavenging, leading to higher modelled concentrations of particulate sulphate in the atmosphere.
A hybrid method to tackle conditional systematic errors of hydrological models
Authors: Rozos Evangelos
Published: February 2023

Machine learning has been used in hydrological applications for decades. Recent studies, after a systematic comparison, have shown that machine learning models (more precisely, deep learning with thousands of nodes) can outperform even the most sophisticated physically based models. Furthermore, one of the basic criticisms, that machine learning produces black box models, has been addressed by researchers, who have indicated how this black box can be made transparent to obtain explainable/interpretable results. However, the main disadvantage of the machine learning approaches (especially deep learning, which may employ hundreds of thousands of parameters) remains the CPU-intensive training process. This disadvantage can be overcome by employing hybrid modelling frameworks that combine simple machine learning models with parsimonious hydrological models. The drawback of these parsimonious approaches is the susceptibility of the latter to conditional systematic errors, which propagate through the modelling framework and cannot be eliminated by simple machine learning networks (employing complex networks would nullify the sought benefit of reduced CPU times). In this study, we suggest methods to cope with this kind of error and achieve a modelling performance close to the best achievable with the available data.
Numerical investigation of compaction effects on pore structure and hydraulic properties of fluid-saturated granular materials
Authors: Safari Anarkouli Soheil , Lanzendörfer Martin
Published: February 2023

Since there is no doubt that soil compaction can induce substantial changes in the soil properties, affecting all kinds of physical, chemical, and biological processes in soils, it is worth some effort to attempt to characterize these changes quantitatively [1]. Soil properties, such as its permeability and hydraulic conductivity or the pressure-saturation relations, to name a few, are closely related to the pore space geometry, in particular to the pore size distribution (PSD). Future progress in incorporating the soil hydraulic properties in the modeling studies related to soil compaction will require, among others, an enhanced understanding of how PSD evolves during the compaction process. In addition to much-needed experimental observations, we believe that a significant part of this endeavor should be devoted to making use of the available pore-scale numerical techniques.We will focus on the approach based on obtaining the pore structure in between the grains (of idealized grain geometries) for given porosity and particle size distribution. In this study, we use the discrete element method (DEM) [2] to obtain the evolution of pore structure by simulating the movement of grains during the compaction process, for a variety of sphere packings (mono-sized particles and binary mixtures, to start with). For this purpose, we use the open-source platform Yade-DEM [3]. The hydraulic properties of the fluid-saturated granular materials are simulated with the pore-scale finite volume (PFV) model [4]. Also, we use a combination of regular Delaunay facets and regular Voronoi vertices to extract the geometry of the pore structure. The effects of compaction on the pore structure and the hydraulic properties of different spherical packings will be discussed. References:[1] Mahmoodlu, M. G., Raoof, A., Sweijen, T., & Van Genuchten, M. T. (2016). Effects of sand compaction and mixing on pore structure and the unsaturated soil hydraulic properties. Vadose Zone Journal, 15(8).[2] Cundall, P.A., and Strack, O.D.L. (1979) A Discrete Numerical Model for Granular Assemblies. Geotechnique, 29, 47-65.[3] V. Šmilauer et al. (2021), Yade Documentation 3rd ed. The Yade Project. (http://yade-dem.org/doc/)[4] Chareyre, B., Cortis, A., Catalano, E. et al. (2012). Pore-Scale Modeling of Viscous Flow and Induced Forces in Dense Sphere Packings. Transp Porous Med 92, 473–493.
Trends and Variability in Extreme Precipitation over India
Authors: Sajeevan Thankamani Chaithra , AchutaRao Krishna
Published: February 2023

The frequency, intensity and duration of weather and climate extremes have increased globally over the past several decades, and the trend is projected to continue. It is important to understand the changing nature of these extremes as it contributes to better monitoring and prediction, thereby reducing the risk to society. Changes in climate and associated weather extremes may be caused both by natural factors such as internal variability, volcanic eruptions, and solar variability as well as anthropogenic factors such as GHGs, aerosols and land use changes. It is essential to differentiate between the contributions of these drivers in order to take suitable measures to mitigate and adapt. Though the changes in temperature extremes are well-documented, rainfall extremes are significantly heterogeneous around the world.This study analyses extreme precipitation indices over India (developed by the Expert Team on Climate Change Detection and Indices; ETCCDI) and their relationship with different modes of climate variability. The study examines the mean climatology, long-term trends and variability in extreme precipitation indices over India using the daily gridded rainfall data from the India Meteorological Department (IMD). The analysis is carried out over different homogeneous zones as well as custom-defined areas over India in different seasons. The study finds significant variability of extreme indices in the 2 to 4 year time scales and highlights the role of Indian Ocean Dipole (IOD) and El Niño-Southern Oscillation (ENSO) in modulating extreme precipitation. 
Revealing the mutual information between seismic and geodetic data in Guerrero, Mexico
Authors: Seydoux Leonard , Steinmann René , de Hoop Maarten , Campillo Michel
Published: February 2023

Significant slow-slip events are primarily observed in geodetic data and may occur during tremors and low-frequency, often referred to as "slow earthquakes" seen in the seismic data. The link between slow earthquakes and slow-slip events is still being discussed nowadays, mainly because of the difficulty of defining the seismic signatures of slow earthquakes on the seismic signal level. However, detecting the seismic signatures associated with slow-slip events would be a crucial step toward understanding these phenomena and their role in the seismic cycle. This study demonstrates how machine learning principles can help interrogate the relationship between geodetic and seismic data. We condense the information carried by the continuous seismograms recorded by a single station in Guerrero, Mexico, over a decade. Using a deep scattering network with ICA, we obtain seismic features at an hourly sampling rate that we compare with the geodetic data. Our method shows that we can explain the geodetic movements with a few seismic features, suggesting that the seismic radiations of slow-slip events are well-defined. We further examine the properties of the associated seismic wavefield and infer the contribution of each class to the overall displacement observed in the geodetic data.
Exploring evolution of feather function in early birds and dinosaurs
Authors: Cockx Pierre , Benton Michael
Published: February 2023

Feathers are key innovations that underpin the evolutionary success of birds, and biologists have achieved a solid understanding of modern feather types and their functions. Nonetheless, the unexpected recent discoveries of several specialized feather morphologies in extinct birds and related dinosaurs, challenges our views of the overall evolution of feathers. Such discoveries raise large evolutionary questions in a wider group than simply birds (i.e., dinosaurs as well as pterosaurs). These are related, for instance, to the initial function of feathers, subsequent feather diversification and functions, and potential links between such evolution and external factors. We have differentiated and inventoried fossil feather types based on their general morphological structure, and coded these as traits that relate to feather functions. We analyse the dataset through computational phylogenetic comparative methods, including ancestral state reconstructions, to identify the points of origin for each feature and estimate patterns and rates of evolution. Monofilamentous integumentary structures appear synapomorphic to Avemetatarsalia. A loss of monofilamentous integumentary structures occurred within Pennaraptora. While the presence of pennaceous feathers is synapomorphic for Pennaraptora, the presence of pennaceous feathers on the hindlimbs is a synapomorphy of Paraves. There is greater complexity, however, in feather evolution, with uncertainty over convergence and uniqueness of some feather types not seen in modern birds. The analysis allows some connection from feather morphology evolution to the sequence of regulatory gene switches in modern feather ontogenetic development, but the fossils suggest a richness of evolution not directly seen in studies of feather evo-devo.