bluuebunny/crossref_metadata_2025 huggingface dataset:
Segmented Mantle Melting, Lithospheric Rheology and Transform Fault Formation
Authors: Martinez Fernando , Hey Richard
Published: February 2023

Mantle melting along mid-ocean ridges occurs in a segmented manner.  Melting and melt extraction are greatest within ridge segment interiors but near segment ends mantle upwelling decreases, cooling increases and melt extraction becomes inefficient.  Owing to the strong influence of water on mantle rheology, these effects have important consequences for the strength of oceanic lithosphere.  Residual mantle formed in ridge segment interiors is melt-depleted and dehydrated forming strong rheological bands.  Near segment ends, however, the formation of low-degree hydrous melts predominates, and these are inefficiently extracted from the mantle.  On solidification, these hydrous melts can re-fertilize surrounding mantle with water due to the high diffusivity of hydrogen in mantle material. This results in weak hydrous bands of mantle material near segment ends.  Thus, segmented mantle melting creates a corresponding segmented oceanic mantle rheological structure that favors the localization of shear deformation in the weak bands near segment ends.  Further strain localization within these weak zones may then facilitate additional weakening processes along discrete narrow transform fault zones. We Illustrate our model with geophysical observations from the Reykjanes Ridge and northern Mid-Atlantic Ridge south of Iceland.  The Reykjanes Ridge is a ~1000 km long linear axis without transform faults.  Rapid propagation of melting anomalies along its linear axis precludes a stable magmatic segmentation as shown by its linear mantle Bouguer anomaly.  Immediately south of the Reykjanes Ridge, the northernmost segments of the Mid-Atlantic Ridge have prominent mantle Bouguer anomaly lows indicating stable cells of segmented mantle melting. Transform and non-transform discontinuities immediately form at the ends of the mantle Bouguer anomaly lows.  This model can be extended to explain the occurrence (or absence) of transform faults over the full range of spreading rates from ultra-slow to ultra-fast ridges.Reference: Martinez, F., and R. Hey (2022), Mantle melting, lithospheric strength and transform fault stability: Insights from the North Atlantic, Earth and Planetary Science Letters, 579, doi:10.1016/j.epsl.2021.117351.
Hydrometeorological System for Seasonal Streamflow Forecasting at Brazilian Hydro Power Enterprises
Authors: Bomfim da Silveira Reinaldo , Freitas Camila , Silmara Aver Paranhos Cassia , Cristina Pinheiro Luciane , Santos Roberto , de Campos André Luiz , Ávila Rangel Leandro , Rogiski da Silva Nathalli , Mainardi Fan Fernando , de Araújo Gama Cléber Henrique , Quedi Erik , Petry Ingrid
Published: February 2023

The Electric Energy Company of Parana (COPEL GeT), the Meteorological System of Parana (SIMEPAR) and RHAMA Consulting company are undertaking the research project PD-6491-0503/2018 for the development of a hydrometeorological seasonal forecasting for Brazilian reservoirs. The project, sponsored by the Brazilian Electricity Regulatory Agency (ANEEL) under its research and development programme, aims the forecasting of streamflow, at temporal scales ranging from 1 to 270 days, at hydro power enterprises, which are integrated by the National Power System Operator (ONS) through its Interconnected System (SIN). We present in this work the framework built up as interface to the results of this project, which integrate shapefiles of main river basins in Brazil, hydro meteorological information, forecasts of precipitation from seasonal models (e.g., ECMWF’s SEAS5) and derived streamflow from hydrological model used in the project (MGB-SA mainly) for the entire electric energy network of the country. The platform encompasses layers of maps and graphics synchronized by date, respectively to locations of hydro power plants in Brazil, which allows users to perform multiple analysis for either energy planning or routine hydraulic operations. We shall demonstrate examples of applications, such analysis of a flood event happened during the 2014/2015 El Niño episode, which caused heavy precipitation, increased river level and flow into reservoirs in the Iguaçu River basin, disruption of services and economic losses in the South of Brazil. Given the limitations of seasonal precipitation forecasting, the model was successful in predicting the heavy accumulated rainfall in the analyzed period. In parallel, the hydrological model was able to simulate flow peaks well in advance. In addition, the platform allows an overview of the SIN subsystems and respective stored energy, which allows intercomparison and pragmatic analysis of the country's electric energy capacity.
Detailed Examination of Upper Troposphere Lower Stratosphere Composition Change from In Situ Observations of Active Convection in the United States
Authors: Gordon Andrea , Homeyer Cameron , Smith Jessica , Bui T. Paul , Dean-Day Jonathan , Hanisco Thomas , Hannun Reem , St Clair Jason , Wofsy Steve , Pittman Jasna , Daube Bruce , Sayres David , Pandey Apoorva
Published: February 2023

Tropopause-overshooting convection in the midlatitudes provides a rapid transport pathway of air from the lower troposphere to the upper troposphere and lower stratosphere (UTLS), and can result in the formation of above-anvil cirrus plumes (AACPs).  Recent in situ observations from the Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) field campaign are used to examine impacts from active overshooting convection on UTLS composition. There are little to no prior airborne observations of active overshooting convection, making observations from this flight valuable to interpreting and exploring processes seen in idealized modeling studies. DCOTSS research flight 13 on May 31st, 2022 sampled active overshooting convection over the state of Oklahoma for more than three hours with the NASA ER-2 high-altitude research aircraft. Additionally, an AACP was bisected during this flight, providing the first such extensive sampling of this phenomena. This study aims to provide a detailed understanding of changes in the UTLS composition from active overshooting convection and AACPs using the in-situ observations from this flight. The observations reveal multiple pronounced changes in air mass composition and stratospheric hydration. In agreement with prior modeling studies, maximum altitudes of water vapor enhancement were much higher than altitudes of mostly passive trace gas composition change. Stratospheric water vapor enhancements reached nearly a factor of four over background levels at a maximum altitude of 16.56 km and a potential temperature of 389.76 K. Carbon monoxide, a tracer of tropospheric origin, showed enhancements of a factor of two over background levels at a maximum altitude of 15.76 km and potential temperature of 363.6 K. There is a notable positive correlation between water vapor and ozone near the bisection of the AACP, which seems to be the result of horizontal mixing. It appears that the water vapor enhancement within the AACP was limited to the saturation mixing ratio of the low temperature environment.
Modelling fluid flow and water-rock interaction in fractured crust using a Discrete Fracture Network approach
Authors: Harb Ibrahim , Grandia Fidel , Trinchero Paolo , Hyman Jeffrey
Published: February 2023

Groundwater accounts for around 25% of the world’s fresh water supply. Due to the increasing anthropogenic pressure on shallow aquifers as well as climate change that is impacting global groundwater recharge, there is an increasing need to access deeper groundwater resources, which are frequently hosted in fractured-rock formations. The migration of groundwater (and other types of fluids, in general) in fractured rocks allows the contact between fluids in geochemical disequilibrium with the host rocks (i.e., large geochemical gradients) promoting water-rock reactions inside the fractures. These reactions may influence the permeability and porosity, as well as they may lead to fracture sealing. So, a thorough understanding of the coupled hydro-chemical processing that occur in fractured media is important for applications such as the sustainable exploitation of the afore-mentioned reserves, the protection and remediations of aquifers used for drinking water production or the safety analyses of deep geological repositories for spent nuclear fuel, energy storage, nuclear waste disposal sites, etc.. In fractured rocks, groundwater flows in specific pathways and interacts with the host rock which may lead to the change in the hydro-geochemical conditions. The prediction of these interactions become critical for a proper management of the different applications. Therefore, the understanding and modelling of fluid-fracture interaction is of high scientific and commercial interest.Using the software dfnWorks, it is possible to model the fluid transport using a non-reactive Lagrangian method (particle tracking). In this contribution, we intend to implement geochemical reactions in dfnWorks to quantify the impact of these reactions in the fracture network. In fact, flow of water through Discrete Fracture Networks leads to interaction between water and the minerals occurring in the fracture plane and thus alters the underlying groundwater flow patterns. Thus, using these DFN-based reactive transport simulations, we aim at predicting the effect that chemical reactions have on flow and channeling. Besides presenting a proof-of-concept set of calculations, we will also present preliminary results of a real-case application, where fracture filling is produced as a result of a chemical imbalance.
Constraints of Relative Sea Level Change on the Late Pleistocene Deglaciation History
Authors: Kang Kaixuan , Zhong Shijie
Published: February 2023

In this study, we examine the relationships among mantle viscosity, ice models and RSL data. We analyzed two widely used ice models, the ANU and ICE-6G ice models, and found significant difference between these two models, suggesting that significant uncertainties exist in ice models. For six RSL datasets covered both the near- and far-field from published works [Peltier et al., 2015; Lambeck et al., 2014, 2017; Vacchi et al., 2018; Engelhart et al., 2012, 2015], we performed forward GIA modelling using a 1-D compressible Earth model to seek the preferred upper and lower mantle viscosities that fit each of the six RSL datasets, for each of these two ice models. Our calculations show that viscosity in the lower mantle is significantly larger than the upper mantle for almost all the pairs of RSL datasets and ice models, but the RSL datasets for North America and Fennoscandia by Peltier et al., [2015] can be matched similarly well with a large parameter space of upper and lower mantle viscosities, both relatively uniform mantle viscosity and with large increase with depth. The preferred mantle viscosity using the ANU ice model and Lambeck et al. [2017] RSL data for North America is in a good agreement with that by Lambeck et al. [2017].    By using the GIA model with the preferred viscosity structures, we constructed the spatial and temporal distributions of misfit to different RSL datasets, for both the ICE-6G and ANU ice models. The misfit patterns for the ANU and ICE-6G ice models do not differ significantly in North America, although these two ice models differ greatly in North America. However, due to relatively small ice volume in ICE-6G, it fails to explain the far-field RSL data, reflecting the so-called “missing ice” problem. Guided by the spatial and temporal misfit patterns, we made initial attempts to modify ICE-6G by adding more ice to the ice model to improve the fit to far-field RSL data. The three modified ICE-6G ice models we consider all significantly improve far-field RSL data, while maintaining or even improving misfit for near field RSL data. This shows the promise with our method in improving ice models and fit to RSL data.
Evolution of tides and tidal dissipation over the last glacial cycle
Authors: Wilmes Sophie-Berenice , Pedersen Vivi Kathrine , Schindelegger Michael , Green Mattias
Published: February 2023

Simulations of the tides from the Last Glacial Maximum (26.5 – 19 kyr BP) to the present show large amplitude and dissipation changes, especially in the semi-diurnal band during the deglacial period. New reconstructions of global ice sheet history and sea levels covering the last glacial cycle allow us to extend the tidal simulations from the last interglacial (~125 kyr BP) to the present. Climate during this period was far from stable with periods of ice sheet advance and lower sea levels interspaced with ice sheet melting and sea level increases. Here, using the sea level and ice history from Gowan et al. (2021; 80 kyr BP to present) and sea level simulations based on the ICE6G_C ice history (Peltier et al., 2015; 122 kyr BP to present), we present simulations of tidal amplitudes and dissipation over the last glacial cycle using the tide model OTIS for the tidal constituents M2, S2, K1 and O1. Our results show large variations in amplitudes and dissipation over this period for the M2 tidal constituent with several tidal maxima, whereas for the other constituents, changes are mainly regional. Due to the lower sea levels and altered bathymetry, open ocean dissipation was enhanced with respect to present day levels for most of the glacial cycle for all constituents. This result is important in the context of historical ocean mixing rates. We further highlight the impacts of the differences in bathymetry and ice sheet reconstructions on global tidal dissipation.Gowan, E.J., Zhang, X., Khosravi, S., Rovere, A., Stocchi, P., Hughes, A.L., Gyllencreutz, R., Mangerud, J., Svendsen, J.I. and Lohmann, G., (2021), A new global ice sheet reconstruction for the past 80 000 years, Nature Communications, 12(1), 1-9.Peltier, W. R., Argus, D. F., and Drummond, R. (2015), Space geodesy constrains ice age terminal deglaciation: The global ICE-6G_C (VM5a) model, J. Geophys. Res. Solid Earth, 120, 450– 487, doi:10.1002/2014JB011176.
The volcano-tectonic setting of the Eastern Carpathians: from detailed gas-geochemical surveys towards gas monitoring planning
Authors: Kis Boglarka-Mercedesz , Caracausi Antonio , Palcsu László , Szalay Roland , Zsigmond Andreea-Rebeka , Viveiros Fátima , Aiuppa Alessandro , Randazzo Paolo , Harangi Szabolcs
Published: February 2023

The Eastern Carpathians are characterized by CO2-dominated, intense, cold gas emissions starting from the Neogene to Quaternary volcanic structures, the youngest dormant volcano, Ciomadul, but occurring also quite far away from these, in the Cretaceous flysch units.The gases are often transported to the surface through groundwater and appear in the form of bubbling mineral water springs. The major components of these cold gas emissions are: CO2, CH4, N2 and sometimes H2S. This is the most intensive degassing area from Romania. The gas emissions often appear in inhabited areas, representing a natural risk for locals.In the recent years we performed detailed geochemical surveys, in which the chemical composition of the free gases, the origin of the different gas species and also the quantification of fluxes from diffuse emissions from the soil and dissolved gas was investigated. We have used different approaches and methods, starting with a specially designed Multi-GAS instrument for low-temperature gases, towards different monitoring experiments.Our results show that the chemical and isotopic compositions of the investigated fluids throughout the Carpathians are strongly influenced by processes that characterize the geotectonic setting of the study area, such as the former volcanic activity and the subduction. In the present the occurrence of the gas emissions and the high flux areas are dependent on the tectonic structures, namely the nappe systems of the Carpathians and related faults, which represent a pathway for the deep fluids towards the surface.All our investigations gave us a general view on the quantity, flux, geochemistry and origin of the fluids in the study area and helped us to select the most suitable and appropriate sites for future gas monitoring projects.This work was supported by a grant of the Romanian Ministry of Education and Research, CNCS - UEFISCDI, project number PN-III-P1-1.1-TE-2019-1908, within PNCDI III, contract number TE 63/2020.
On the global synchronicity of glacial vegetation changes
Authors: Weitzel Nils , Adam Moritz , Sanchez Goñi Maria Fernanda , Ledru Marie-Pierre , Montade Vincent , Zorzi Coralie , Rehfeld Kira
Published: February 2023

Vegetation responds to local climate and carbon dioxide changes with response times ranging from decades to millennia, depending on location, spatial scale, and vegetation characteristic. Here, we focus on orbital timescales, for which all available estimates suggest an equilibrium of vegetation and climate. Over the course of the last glacial period, global mean temperature varied between minima during Marine Isotope Stage (MIS) 4 and MIS2, and a maximum in MIS3. If orbital-scale climate changes followed this global trend across most of the globe, we would expect vegetation changes to feature a similar temporal evolution.Leveraging a global compilation of pollen records, we quantify the synchronicity of orbital-scale vegetation changes within and across regions during the last glacial period. We use the arboreal pollen fraction, statistical mode decompositions, and key taxa as indicators for forest cover changes. Our results suggest that a globally coherent forest cover minimum occurred during MIS2. However, we do not find evidence for other periods of coherent forest cover trends across the globe or either hemisphere. This indicates that vegetation changes were more regionally confined during earlier parts of the last glacial. As chronologies become more uncertain further back in time, we examine the likelihood of dating errors to explain the absence of globally coherent vegetation changes during MIS4 and MIS3. Finally, we compare our results with simulations of climate and vegetation to assess if models capture the diagnosed forest cover trends found in the pollen records. Moreover, this comparison allows us to infer the influence of temperature, moisture availability, and carbon dioxide on vegetation variations during the last glacial period.
Hydrological Signature Representation of 7533 KGE Calibrated Conceptual Model Structures
Authors: Spieler Diana , Schütze Niels
Published: February 2023

Discussions calling for more rigorous evaluation practices for hydrologic models have recently increased. In addition to the widely used integral objective functions, hydrologic signatures are becoming common evaluation metrics for proving the suitability of hydrologic models for specific application purposes.This work calibrates 7488 fixed conceptual model structures using KGE as an objective function. These structures range from a 1 to 3 storage model space previously used for an automatic model structure identification experiment. In this experiment we simultaneously calibrated the model structure (number of stores and flux equations) and its parameter values. Additionally, we calibrated 45 literature-based model structures (MARRMoT Toolbox) to extend the structural diversity in the analyzed models. We select well-performing models based on their KGE value (as is common practice) and analyze their performance using 12 selected hydrological runoff signatures. These signatures represent five aspects of the hydrological regime (magnitude, frequency, duration, rate of change, and timing). The large number of model structures, calibrated to the streamflow of 12 MOPEX catchments, allows general insight into how well common conceptual model structures can represent observed hydrological behavior evaluated by signatures.Results show a general behavior of model structures calibrated to KGE to perform well in representing runoff ratio, mean discharge, the 95th streamflow percentile, and the mean half-flow date. However, the analyzed conceptual model structures struggle to represent low flow and frequency signatures. When evaluated only for KGE, we can identify dominating model structures over all catchments. When evaluated for signatures, there are no model preferences over all analyzed catchments but different models seem to have their merits under specific conditions. These results support the need for ensuring model adequacy for a given task.
Emergent pattern analysis of multiple-phase droughts cascade in Central Asia from a dynamic perspective
Authors: Tian Lu , Huang Jingshui , Disse Markus
Published: February 2023

Drought is typically induced by the extreme water deficit stress that cascades through the atmosphere, hydrosphere, and biosphere. However, identifying individual cascade connections remains challenging due to the nonlinear interactive loops within drought cascades initiated by numerous physical elements, which hinder the emergent patterns of droughts cascade from being explored further.In this study, we establish a statistical framework for characterizing the dynamic space-time behaviour of droughts to track the droughts cascade. We investigate four typical droughts: precipitation (PCP), evapotranspiration (ET), Runoff, and root-zone soil moisture (SM) throughout Central Asia, the typical arid and semi-arid area of the world. Then, this method extracts 15 emergent patterns of droughts cascading corresponding to the different temporal orders. Moreover, the 15 emergent patterns of droughts cascade are categorized further as two-phase, three-phase, and four-phase drought cascading patterns in keeping with the appearance of hydrological parameters.The result shows the highest occurrence in the four-phase cascading pattern, manifesting that the drought in PCP, ET, Runoff, and SM are expected predominantly to occur consecutively across the study area. Additionally, we find that four variations coefficients of duration, intensity, severity, and area reveal a positive linear relationship during cascading processes. Furthermore, the distribution range and magnitude of four metrics (duration, intensity, severity, and area) of PCP droughts increase with the rising of phase number in all cascading patterns.Traits of the drought cascade provide another perspective for the drought early-warning and impact forecast in Central Asia, which could support the decision-making on drought mitigation in the arid region under exacerbated water deficit stress from global warming.Keywords: group behaviour of droughts, cross-temporospatial scale, arid region, water management
Ba, Sr and Rb feldspar/melt partitioning in the basanite-phonolite suite from Teide-Pico Viejo volcanic complex, Tenerife.
Authors: Dorado Olaya , Wolff John A. , Ramos Frank , Marti Joan
Published: February 2023

The behaviour of Group I and II elements during the petrogenesis of felsic igneous rocks is largely controlled by feldspar-liquid relationships and processes. Numerous experimental studies have addressed plagioclase/melt element partitioning, with fewer studies devoted to potassium feldspar, and very few to albite-rich ternary-composition feldspar (An ~ Or < Ab). However, the partition coefficient for Ba is known to increase at least 10-fold through the crystallization sequence sodic plagioclase – anorthoclase – potassium feldspar that is typical of sodic alkaline suites. Consequently, melt Ba concentrations may drop by orders of magnitude along such a liquid line of descent. Feldspars, glasses and whole rocks in such suites may exhibit strong enrichments and depletions in Ba that can be used to track processes of crystal fractionation, cumulate formation, and cumulate recycling.Here, we review experimental feldspar/melt partitioning data for Ba, Sr and Rb as a function of feldspar composition. Regression of available experimental data offers the basis for expressions that appear to provide a working description for the compositional dependence of partition coefficients for albite-rich compositions. We have applied this model to feldspar and melt compositions of the products of several Holocene eruptions (Pico Viejo C, Pico Viejo H, Teide J2, Lavas Negras, Arenas Blancas, Montaña Rajada and Montaña Reventada) of the basanitic-phonolitic suite of the Teide-Pico Viejo volcanic system (Tenerife, Spain). Comparing feldspar/groundmass pairs obtained by EMPA and LA-ICP-MS analyses with predicted partition coefficients obtained with the models allows us to attribute an antecrystic or xenocrystic origin to some of the feldspars. The results confirm the existence of a distinct population of cumulate feldspars, that had undergone multiple fusion and recrystallization events, in Lavas Negras and Arenas Blancas flows. In addition, the trachytic composition of Montaña Reventada is due to melting of a feldspar-dominated cumulate. Application of these techniques to active magmatic systems will allow us a better understanding of different pre-eruptive processes, and ultimately improve volcanic hazard assessment.This research was funded by the Intramural CSIC grant MAPCAN (Ref. 202130E083). OD was supported by an FPU grant (FPU18/02572) and a complementary mobility grant (EST19/00297) from the Ministry of Universities of Spain.
Deep learning diffraction separation for seismic and GPR data
Authors: Bauer Alexander , Schwarz Benjamin , Walda Jan , Gajewski Dirk
Published: February 2023

Within the last decade, the diffracted wavefield has gained increasing importance for the processing of both seismic and ground-penetrating radar (GPR) measurements. In both communities, the separation of the diffracted wavefield remains a notorious challenge that has been approached with different deterministic methods, ranging from poststack wavefront attributes to plane-wave destruction and coherent wavefield separation. While each of these deterministic methods has characteristic advantages and drawbacks, all of them require the adaptation of processing parameters for each application, particularly when crossing scales from seismic to GPR measurements. In this study, we propose to train a convolutional autoencoder to separate the reflected and diffracted wavefields in a generalized fashion. For this purpose, we have generated highly variable synthetic seismic data that contain reflections, diffractions and noise using an algorithm that allows to compute each component individually, resulting in an automatized generation of data and labels. In order to account for the complexity of field data, we complemented the synthetic data with a large set of reference seismic and GPR field data results from coherent wavefield separation, a deterministic method, in which the reflected wavefield is modeled and adaptively subtracted from the input data. With this dataset we trained a supervised convolutional autoencoder and applied the trained neural network to seismic and GPR field measurements that were not part of the training data. The results show that the trained autoencoder is able to generalize and successfully separate the reflected and diffracted wavefields even for complex field data, resulting in an on-the-fly diffraction separation that requires no choice of parameters and is likewise applicable to both seismic and GPR data.

 

 

 
 
Voyager 2 Radio Occultation of Triton revisited using modernized analysis tools
Authors: Togni Andrea , Caruso Andrea , Buccino Dustin , Zannoni Marco , Oudrhiri Kamal , Tortora Paolo
Published: February 2023

In 1989 the Voyager 2 spacecraft performed a flyby of the Neptune system. In particular, a radio occultation of Triton’s ionosphere was performed on 25 August 1989. Results from this occultation experiment were published in Science by Tyler et al., and the atmospheric profiles of Triton were estimated via analysis of the real-time tracking and monitoring systems data at time resolutions of about 1 second.In recent years, thanks to an increase in the computational power of microprocessors and an expansion in their fields of application, there has been a surge in the development of optimal estimators for stochastic signals. In this context, we present a re-analysis of the radiometric data received by the Voyager 2 spacecraft during its radio occultation experiment of Triton. Using one of the latest algorithms developed in the field of signal parameters estimation, we use the radiometric measurements received during the ingress and egress phases of the mission to accurately reconstruct the sky frequency, as received by the DSS-43 antenna at the time of occultation. In particular, by performing spectral interpolation and tuning the processing parameters, we increased the frequency resolution and detection threshold around the ingress and egress epochs to maximize the scientific return from the radiometric data collected over 30 years ago.Since Voyager 2 transmitted two coherently related signals (at S and X bands), the two series of sky frequencies can be combined to isolate the Doppler frequency shift due to dispersive effects. The latter is used to compute the electron number density profiles inside the Triton ionosphere using a classical Abel transform-based method. Also, a Monte Carlo procedure is used to evaluate uncertainties in the derived profiles. The results of this analysis are consistent with those presented in the past literature, with the only difference of a slight (but important for the planning of future missions) shift in the ionosphere's peak altitude due to the use of updated Voyager and Triton ephemerides. The methods and data analysis approaches presented in this work are very relevant to the exploration of the Ice Giants, in particular for radio science observations of satellite tenuous exospheres and ionospheres. 
Mechanisms of pressure buildup in magma reservoir: insights from numerical experiments
Authors: Podladchikov Yury , Utkin Ivan , Khakimova Liudmila
Published: February 2023

Understanding mechanisms leading to volcanic eruptions are of fundamental importance in geology and volcanology. A prerequisite to a volcanic eruption is the generation of sufficient overpressure in a magma reservoir, enough to exceed the strength of the rock, potentially triggering the volcanic eruption. In geological models, the pressure buildup in magma reservoir is often linked to magma recharge and volatile exsolution. Another mechanism, that is often overlooked in conventional geological models, is related to the isochoric rise of gas bubbles in almost incompressible magma saturated with volatiles. Predicting volcanic eruptions using numerical models is complicated by the need to solve coupled physical processes spanning multiple temporal and spatial scales.We present a coupled thermo-chemo-hydromechanical mathematical model for predicting the pressurization of a magmatic reservoir. The model predicts porous and free convection of partially crystallized magma due to thermal and compositional heterogeneities, and compaction of crystals due to density difference between solid and liquid phases. We describe thermodynamic equilibrium and thermo-mechanical properties of phases using the nonlinear equation of state obtained through direct Gibbs energy minimization. We resolve the multi-scale processes within the magma reservoir using high-resolution numerical modeling based on supercomputing.We demonstrate through numerical experiments that the two mechanisms, volatile exsolution due to retrograde boiling, and rising of gas bubbles in a  nearly isochoric system, could lead to pressure buildup in a magma reservoir, sufficient to exceed rock strength. We study systematically the relative importance of these mechanisms in a simplified problem setup.
An Overview of TROPESS Data Products and Services at the NASA GES DISC
Authors: Johnson James , Iredell Lena , Gerasimov Irina , Morgan Kristan , Wei Jennifer
Published: February 2023

The TRopospheric Ozone and Precursors from Earth System Sounding (TROPESS) project generates Earth System Data Records (ESDRs) of ozone, and other atmospheric constituents (CH4, CO, H2O, HDO, NH3, PAN and temperature) by processing data from multiple satellites through a common retrieval algorithm and ground data system. Satellite Level-1B input data used in generating the TROPESS L2 data products include CrIS NOAA-20 (JPSS-1), CrIS SNPP, AIRS Aqua, OMI Aura, and TROPOMI S5P. The common retrieval framework is known as the MUlti-SpEctra, MUlti-SpEcies, Multi-SEnsors (MUSES) science data processing system (MUSES-SDPS). Several of the TROPESS data products are now available from the NASA Godddard Earth Sciences Data and Information Service Center (GES DISC) for users to download.In this presentation we provide an overview of the various TROPESS data products. These data products can be divided into the following Forward Stream types: Standard Products, Summary Products, and Full-Archival Products.  Standard Products are for users that are doing full analysis with avenging kernel and covariance corresponding to retrieved vertical profiles. Summary products have a smaller file size and are more convenient for first-look and rapid analysis, include total and partial columns, as well as column averaging kernels. The Full-Archival Products will contain all information used in creating the data. TROPESS also creates Special Products, provided on an as-needed and as-available basis to support NASA field missions and individual-investigator requests over specific regions. Eventually, TROPESS will also produce and deliver a set of Reanalysis Stream products.Data at the GES DISC are being transitioned into the "Cloud". This will allow users with "Cloud" access to perform data analysis directly on the data without downloading the data to their system. Services, such as subsetting and data visualization, will also be provided for TROPESS data products at the GES DISC.
Effects of Ocean Mesoscale Processes on Biogeochemistry
Authors: Casaroli Lucas , Ilyina Tatiana , Chegini Fatemeh
Published: February 2023

Mesoscale processes contemplate movements in the ocean ranging from tens to hundreds of kilometers. At this scale it is possible to observe phenomena such as eddies, vortices, fronts among others. These processes are of great importance to biogeochemical cycles as they, for example, can affect the transport of nutrients to the euphotic zone by vertical movements, alter the mixed layer depth through vertical displacement of isopycnals, as well as trap biological, chemical and physical properties inside eddies and meanders.Ocean General Circulation Models (OGCM’s) either resolve the mesoscale eddies by increasing the model resolution or parameterize them. The chosen approach regarding the eddies comes with some caveats as it can lead to simulations limited to small time periods or substantial simplifications of the physical processes, which in turn can alter results and obtain a different configuration for ocean and atmosphere dynamics. Regarding biogeochemical tracers, how eddies are represented in the model bring different outcomes, showing solutions that are model dependent such as ocean regions acting as a net source or sink of nutrients, oxygen and carbon. Hence we can’t accurately constrain the ocean’s role as a carbon sink. Not only the results are model dependent, but also resolution dependent. Ocean models with higher resolutions indicate that the vertical profiles of salinity and temperature are substantially altered by mesoscale activity, thus it is expected that biogeochemical tracers are altered by eddy induced disturbances.We present some preliminary results of the output of the HAMburg Ocean Carbon Cycle model (HAMOCC; Ilyina et al 2013, Jungclaus et al 2020) in a 40 km and 10 km resolution on a global setup. As a result we show how changing the resolution affect on the upper ocean and mixed layer the major biogeochemical tracers and overall the carbon cycle.
Uncertainty quantification of aquifer geometry and groundwater level using electrical resistivity models obtained from transient electromagnetic data
Authors: Aigner Lukas , Roser Nathalie , Hettegger Anna , Höfelmaier Daniel , Cimadom Arno , Michel Hadrien , Hermans Thomas , Flores Orozco Adrián
Published: February 2023

Reliable information about the aquifer geometry and its spatial variability from geophysical methods plays a critical role for various hydrological research questions. Such information can be obtained with the transient electromagnetic (TEM) method that reaches a larger depth of investigation with a smaller survey layout compared to electrical or seismic methods. However, the quantitative interpretation of the resistivity model obtained from TEM data in terms of groundwater level and aquifer geometry might be biased by the non-uniqueness of the deterministic inversion. To overcome such limitations, we propose here to use Bayesian evidential learning (BEL1D) to evaluate the uncertainty of the groundwater level and aquifer thickness interpreted from TEM results using a classical deterministic inversion approach. Additionally, we investigate the effect of different prior model spaces on the uncertainty obtained from BEL1D and use the distance-based global sensitivity analysis (DGSA) to determine whether model parameters with a large uncertainty are actually non-influential on the model response. To test the uncertainty quantification, TEM data were measured at three sites in Austria representative of different hydrogeological settings and groundwater levels, namely: 1) a shallow (1 m - 10 m) aquifer located in the soda lakes of the Neusiedl-Seewinkel Basin in Burgenland, 2) an aquifer in intermediate (5 m – 15 m) depth located in the hydrological open-air laboratory (HOAL) in lower Austria and 3) a deep (> 35 m) aquifer in a farm land located in Upper Austria. We obtain TEM data with the TEM-FAST 48 instrument with a 6 m, 12.5 m and a 25 m square single-loop configuration to achieve sensitivities corresponding to the three different aquifer depths. Additionally, we use electrical resistivity tomography (ERT) and multi-channel analysis of surface waves (MASW) data to assess the TEM inversion results. The interpretation of the TEM inversion results is evaluated with BEL1D to obtain the uncertainty of the groundwater level from the cumulative uncertainty of all layers above the layer representing the groundwater level as well as the thickness of the aquifer. Additionally, we achieve a quantitative evaluation of the solved TEM model uncertainties with the DGSA method as well as with the ERT and MASW inversion results. Our results show a lower uncertainty for the electrical resistivity than for the layer thickness, while the DGSA reveals a decrease of sensitivity with depth.
Newcomb-Benford Law characterization of solar wind magnetic field and geomagnetic indices
Authors: Benedito Nunes Artur , Gamper Jekaterina , Friel Matthew , Gjerloev Jesper , Chapman Sandra
Published: February 2023

A. M. Benedito Nunes (co-first author), J. Gamper (co-first author), M. Friel, J. W. Gjerloev, S.C. Chapman The Newcomb-Benford Law (NBL) prescribes the probability distribution of the first digit of variables under conditions including aggregation. It will not apply where there is strong truncation or a cut-off. We apply it to space weather relevant magnetic field observations and indices for the first time. In upstream solar wind magnetic field OMNI HRO IMF observations we show that the NBL detects the improvement in data quality with the availability of the WIND and later, ACE spacecraft after 1995, in addition to IMP8. The SMR geomagnetic index averages over multiple ground magnetometer time-series and follows the NBL to a consistent high precision across changing solar activity and a ten-fold increase in the number of constituent stations. The AE and SME indices select the extremal signals from a set of stations. AE, which is mostly based on the same stations throughout its record, follows the NBL to a consistent high precision and with weak but statistically significant variation, it follows the NBL less well during relatively strong solar cycle maxima compared to solar minima. Both the number of constituent stations and the station type comprising SME has changed over the SME record. First, in 1996 the number of available stations increased tenfold, but the station type remained homogeneous. The NBL is followed to a consistent high precision through this period, up to 2006. Beyond 2006, new station types are introduced into the composition of SME and this can be seen in an approximately factor of two drop in the precision with which the NBL is followed. Subsequently, the SME record follows the NBL to varying precision which tracks the inclusion and omission of different types of magnetometer in the record. As the use of composite indices becomes more widespread across the geosciences, the NBL may therefore provide a generic 'data flag' to indicate when the constituent raw data, calibration or sampling method has changed.
Geosciences and alternative teaching practices in a French primary school.
Authors: Grandclément David
Published: February 2023

The organisation and functioning of this elementary class is multi-level (from Grade 1 to Grade 5) in all subjects except mathematics where there is individualisation of progress. Teaching is carried out in a class organised in table groups mixing levels, ages, boys and girls. The teaching is based on a change in the posture of the teacher, who is neither omniscient nor infallible but remains a model of human values: he does not know everything, but knows how to access what he does not yet know, he is demanding and benevolent as the pupils, future citizens, must learn to be. Well-being and confidence are the first objectives before learning. The functioning of the class is also based on a class cooperative with elected pupils (president, treasurer and secretary) who have certain responsibilities (meetings, management of certain learning activities, certain small or large projects, certain parts of the life of the class). The organisation of learning time alternates between individual work and cooperative and/or collective work, theory, practice and confrontation with reality.Science teaching is an essential part of learning. It develops curiosity, questioning, the formulation of hypotheses, experimentation and the construction of models for representing the world. In this context, geosciences have a regular place because they provide elements of knowledge and understanding that are central to other subjects in the school curriculum or to understanding the world. The poster will try to show this and some aspects of what the class, in particular, has done to discover tectonic and volcanism in reality.
Deterministic directional wave forecasting in deep water
Authors: Meisner Eytan , Liberzon Dan , Galvagno Mariano , Andrade David , Stuhlmeier Raphael
Published: February 2023

Recent years have seen an extensive increase in maritime activity, including new coastal and offshore infrastructure, increased cargo transport, and research on wave energy converters. While long-term macro-scale wave forecasting has been extensively researched (e.g. Günter & Hasselmann, 1991), with several forecasting models available today, there is a noticeable gap in local-scale deterministic wave forecasting models. Such models are needed to improve the efficiency of the design and operation of offshore installations and vessels, providing close-to-real-time data and short-term predictions of waves and wave-induced forcing.We will report on the development of a new, computationally efficient model, allowing for weak nonlinearities in directional wavefields, based on previous studies on the unidirectional case (Stuhlmeier & Stiassnie, 2021). The model is capable of providing a deterministic forecast of the wavefield inside the prediction domain in time and space, based on measurements conducted over an initial region (Figure 1).The mathematical framework used is the Zakharov equation, which determines the nonlinear cross-corrections to the frequencies between the various modes in the spectrum (Stuhlmeier & Stiassnie, 2019), used to derive the actual velocities at which the various wave field components are propagating.The presentation will elaborate the full mathematical framework, alongside explanations of its benefits with respect to linear predictions. The model’s performance is validated using numerical data of nonlinear directional wavefields, generated using the higher order spectral (HOS) method.Figure 1 – Predictable region in time (vertical axis) based on measurements at initial domain η0(x,y)References​​Günter, H. & Hasselmann, S., 1991. Wamodel cycle 4, Hamburg: German Climate Computing Centre.Raphael Stuhlmeier and Michael Stiassnie. Deterministic wave forecasting with the Zakharov equation. J. Fluid Mech., 913:1–22, 2021.Raphael Stuhlmeier and Michael Stiassnie. Nonlinear dispersion for ocean surface waves. J. Fluid Mech., 859:49–58, 2019.
Interseismic deformation in the Tjörnes Fracture Zone, North Iceland from GNSS measurements
Authors: Barreto Alejandra , Viltres Renier , Matrau Rémi , Ófeigsson Benedikt G , Jónsson Sigurjón
Published: February 2023

The Tjörnes Fracture Zone poses significant seismic hazard to the town of Húsavík and other nearby coastal communities in North Iceland as it is capable of generating earthquakes of magnitude ~7. The 120 km long offset connects the offshore Kolbeinsey Ridge to the onshore Northern Volcanic Zone and accommodates approximately 18 mm/yr of transform motion between the North American and Eurasian plates. Most of the deformation is taken up by the two main structures of the fracture zone. The Grímsey Oblique Rift exhibits bookshelf faulting and consists of steeply dipping faults, arranged en-echelon and striking roughly N-S, bounding a series of left-stepping basins. The Húsavík-Flatey Fault is a ~100 km-long right-lateral strike-slip fault. It is mostly offshore, except for its easternmost ~25 km that comes onshore just north of Húsavík. To assess how the deformation is partitioned within the Tjörnes Fracture Zone and to calculate the rate of seismic moment accumulation on the Húsavík-Flatey Fault we use geodetic data from our North Iceland GNSS network. The network covers an area of roughly 200 km by 130 km in size and includes 21 continuous and 92 campaign-style GNSS stations. The continuous data now span up to ~21 years from 2001 to 2022. The first campaign measurements that focused on the HFF were carried out in 1995 and since then we have expanded the campaign-station network to the West towards Tröllaskagi and Skagafjörður and remeasured the network on several occasions. Data from the 2002, 2007, 2009, 2010, 2011, 2013, 2016, 2019, and 2022 campaigns are included in our study. In addition, several stations from the nationwide ISNET reference station network within our study area also included. The GNSS data is used to produce the most up to date velocity field from North Iceland. Relative to the North American plate, our results show a gradual increase of East velocities towards the Northeast across the two main transform structures that reach roughly 18 mm/yr on the Eurasian plate. At the northern tip of the Tjörnes peninsula, between the two transform structures, the velocities are roughly at half the total rate seen at the easternmost stations on the Eurasian plate. Limited deformation is found Southwest of the Húsavík-Flatey Fault in Tröllaskagi, within the so-called Dalvík zone, located on the North American plate.  These results are used to study the present day-kinematics of the Tjörnes Fracture Zone and to further improve the locking depth and slip-rate estimates of the main lineaments.