bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical Developments on Energy Conversion via the Pressure-Strain Interaction
Authors: Cassak Paul , Barbhuiya M. Hasan
Published: February 2023

Energy conversion between bulk kinetic and thermal energy in weakly collisional and collisionless plasma processes such as magnetic reconnection and plasma turbulence has recently been the subject of intense scrutiny. This channel of energy conversion is described by the pressure-strain interaction. In a closed system, this quantity accounts for all the net change of the thermal energy. It is common to decompose it into pressure dilatation and «Pi-D», which isolates energy conversion via compressible and incompressible physics, respectively. Here, we propose an alternative decomposition of pressure-strain interaction that instead isolates flow convergence/divergence and bulk flow shear. We furnish a simple example to illustrate how Pi-D can be counterintuitive and the new decomposition is intuitive. Moreover, for applications to magnetized plasmas, we derive the pressure-strain interaction in a magnetic field-aligned coordinate system. This results in its decomposition into eight terms, each with a different physical mechanism that changes the thermal energy. Results from particle-in-cell simulations of two-dimensional magnetic reconnection plotting the decompositions in both Cartesian and magnetic field-aligned coordinates are shown. We identify the mechanisms contributing to heating and cooling during reconnection. The results of this study are readily applicable for interpreting numerical and observational data of pressure-strain interaction in both Cartesian and field-aligned coordinates in fundamental plasma processes such as reconnection, turbulence and collisionless shocks.
Scaling, connectivity and correlation length of stylolite, fracture and fault networks
Authors: Koehn Daniel , Hafermaas Daniel , Köhler Saskia , Lang Jürgen , Mathur Bakul , Prabhakaran Rahul , Smith Ruaridh
Published: February 2023

Stylolite, fracture and fault networks are important fluid pathways, especially in low permeable rocks such as limestone and therefore important for subsurface applications including geothermal energy production. These systems grow in both time and space and have a given correlation length. Below the correlation length the system becomes saturated and shows a given scaling, for example in roughness for stylolites. Whereas above the correlation length the roughness or width of the growing system becomes constant. The position of this length varies with time and space whilst also being influenced by the system size. This becomes important when the systems connect, for example fractures that grow and merge together such that they have a given size. In this contribution we show with numerical simulations and natural examples how stylolite, fracture and fault networks scale in time and space, how their correlation length is evolving and how they become connected. We discuss the implications for scaling of larger networks as well as implications for deformation and fluid flow.
3D Monte Carlo simulation of Ganymede's atmosphere - lessons learned from Juno's Ganymede flyby
Authors: Vorburger Audrey , Fatemi Shahab , Galli André , Roth Lorenz , Liuzzo Lucas , Poppe Andrew , Carberry Mogan Shane , Wurz Peter
Published: February 2023

Among Jupiter's satellites, Ganymede undoubtedly has one of the most complex atmospheres. This is primarily due to the fact that Ganymede has its own magnetic field, which forms a small magnetosphere within the much larger magnetosphere of Jupiter. This interaction not only results in atmospheric auroral emissions in the UV range but also strongly influences Ganymede’s space environment.With the recent Ganymede flyby by the Juno spacecraft, new information on Ganymede’s environment has become available. We have included these measurements into our 3D Monte Carlo model, determining Ganymede’s resulting H2O, O2, H2, O, and H atmosphere. Our simulations show that accounting for all major source and loss processes, sublimation is still the dominating source process for the water in Ganymede’s atmosphere, delivering more than three orders of magnitude more molecules to the atmosphere than all other source processes combined. For the non-condensing atmospheric species (O2 and H2), on the other hand, it is the auroral electrons that mainly govern the atmospheric structure and density. The auroral electrons also govern the structure and density of the atomic species O and H, which are mainly added to the atmosphere by electron-impact dissociation of O2 and H2 in the auroral belts. Comparison with available spectroscopic observations of Ganymede’s atmospheric constituents shows that our results agree well with the results inferred from these observations, with the exception of H, where our derived line-of-sight column density is about one order of magnitude lower than the column density inferred from Lyman-α measurements.Our analysis shows that for a complete understanding of Ganymede's atmosphere, simultaneous observations of Ganymede's surface, atmosphere, and plasma environment at different times and locations are particularly important. Such measurements are planned with the Jupiter ICy moons Explorer, in particular with the Particle Environment Package (PEP). In this presentation we will show how PEP will help us learn more about Ganymede’s complex atmosphere, providing simultaneous in-situ electron, ion, and neutral gas measurements.
Using Artificial Intelligence/Computer Vision for Automated Plot Validation
Authors: Mukherjee Joey
Published: February 2023

To monitor the results of our instrument on a daily basis, we create a series of daily plots that are generated in an automated fashion.  In our case, we are creating two plot types for four spacecraft for five different species.  Unfortunately, due to circumstances beyond our control (primarily network and system issues), plots were failing and if not monitored daily, they were unavailable when finally needed.  To solve this problem, we investigated using Computer Vision (OpenCV) to validate our generation of daily plots.  It was surprisingly easy and more advantageous than trying to either monitor it daily or more simplistic methods.  By using the cloud, we were able to improve throughput as well.  Future work would be to use Computer Vision to analyze the data within the plots for actual scientific study.
On the systematic differences between various GNSS solutions
Authors: Bogusz Janusz , Rebischung Paul , Klos Anna
Published: February 2023

Space geodesy is the branch of science that deals with determining the shape and dimension of the Earth using quasars and artificial satellites. However, the use of space techniques is not limited to geodesy, many recent geodynamical interpretations are based on the velocities determined using GNSS (Global Navigations Satellite System). In this regard, reference frame differences as well as processing strategies - Precise Point Positioning (PPP) or Network Solution (NS) - may induce systematic differences of significant values. A first comparison between NGL (Nevada Geodetic Laboratory) PPP-produced and IGS (International GNSS Service) NS-produced (repro3) products showed systematic differences between both sets of displacement time series. While the discrepancies in the noise parameters are quite understandable and interpretable, the systematic disagreements in the velocities or amplitudes of annual signals are concerning. The repro3 daily combined solutions are aligned in origin and orientation to the IGSR3 reference frame, which inherits its origin and orientation from ITRF2014. So the daily repro3 station positions are expressed with respect to the ITRF2014 origin, which follows CM on the long-term, but reflects CF at sub-secular time scales. NGL time series, just like the IGS ones, are aligned to a linear reference frame, IGS14 in their case. Since both the IGS repro3 and NGL time series are in fact with respect to the ITRF2014 origin, this cannot explain the annual amplitude differences we observe. A difference in scale may contribute though, because the NGL time series are aligned in scale to IGS14, but the repro3 time series are not aligned in scale to any reference frame. They inherit their scale from the radial satellite phase center offsets (z-PCOs) in igsR3.atx, so in general we may expect: (1) an average ~8 mm difference between the vertical positions in both sets of time series at epoch 2010.0, (2) an average ~0.2 mm/yr rate between the vertical positions in both sets of time series, (3) small differences in the vertical seasonal signals due to the network effect occurring when the NGL solutions are aligned in scale to IGS14. But the fact that the NGL solutions are aligned in scale to the reference frame, while the IGS solutions are not, might explain some other systematic differences. To verify that, we compared the aforementioned series to a set of special IGS repro3 time series produced at IGN and aligned not only in origin and orientation, but also in scale to the IGSR3 reference frame. The comparison between the series was made at 607 stations distributed around the world. The Up component was investigated, and the data have been cut to the same ranges in all three solutions (namely, IGS, NGL and IGN) to avoid misinterpretations and have a minimum length of 5 years. Velocities as well as amplitudes of annual and draconitic oscillations have been analyzed revealing very interesting spatial patterns in the differences.
Physics-Informed neural networks for gravity field modeling incorporating observation, geometry and density constraints
Authors: Wu Leyuan , Chen Longwei , Livermore Philip , de Ridder Sjoerd , Zhang Chong
Published: February 2023

The physics-informed neural networks (PINN) are emerging as a new tool for gravity field modeling. In some scenarios, such as near-source gravitational fields representation, PINN may have greater potential than traditional spherical/ellipsoidal harmonics solutions, as the latter suffers from both theoretical and numerical divergence problems for sources with complex geometry. By incorporating observational, geometrical and statistical density information into the neural network, we aim to reduce the non-uniqueness of the solution space, therefore obtaining improved accuracy in representing gravity fields, especially near the source body. By transforming the trained gravitational potential into density distribution through Poisson's equation, we also provide a new perspective to observe the evolution of the neural network for gravity field modeling as "redistribution of equivalent density sources". The influence of multiple parameters of the neural network on the performance of the PINN gravity modeling, including its size and shape, distribution of Laplacian and Poisson collocation points, and balance between loss functions of the multiple constraints applied, are also investigated. Numerical results are illustrated using the EROS asteroid model and a regional DEM model of Colorado Geoid Experiment area.
Overview of NASA’s Convective Processes Experiment – Cabo Verde (CPEX-CV) in the East Atlantic in September 2022 and Collaboration with the Joint Aeolus Tropical Atlantic Campaign (JATAC)
Authors: Nowottnick Ed , Zawislak Jon , Nehrir Amin , McCarty Will , Piña Aaron , Reid Jeff , Chen Shu-Hua , Rowe Angela , Sakaeda Naoko , Chen Shuyi , Zipser Ed , Pu Zhaoxia , Robinson Claire , Ferrare Rich , Hristova-Veleva Svetla , Ziemba Luke , Thornhill Lee , Bedka Kris , Kavaya Michael , Tanelli Simone ,   CPEX-CV/JATAC Team
Published: February 2023

A continuation of the National Aeronautics and Space Administration’s (NASA) truncated Convective Processes Experiment – Aerosols and Winds (CPEX-AW) field program flown out of St. Croix, USVI, in the summer of 2021, CPEX – Cabo Verde (CPEX-CV) deployed NASA’s DC-8 from Sal Island, Cabo Verde in September 2022, equipped with a unique and comprehensive suite of active and passive remote sensing and in-situ capabilities that, in combination with the availability of similar spaceborne observations, allowed for the measurements of tropospheric aerosols, winds, temperature, water vapor, and clouds and precipitation. The tropical northern East Atlantic Ocean is a data sparse region that, in boreal summer, offers a unique location to study convective lifecycles and processes in a variety of thermodynamic, dynamic, and aerosol environments, such as within persistent (e.g., Intertropical Convergence Zone, ITCZ) and periodic (e.g., African easterly waves and tropical cyclones) large-scale forcing, local terrain effects (e.g., land-ocean transition off western Africa), and aerosol-cloud interactions (e.g., Saharan air layer). In addition to observing the interaction between large-scale environmental forcing and convective systems, the payload is uniquely capable of observing the smaller-scale processes within the near-environment of convection, including those within the marine boundary layer (e.g., cold pools), the inflow/outflow of the storm, and dust-cloud interactions, that affect convective initiation and lifecycle, as well as other poorly resolved/understood properties of these systems.CPEX-AW and -CV were a part of a joint observing effort with the European Space Agency (ESA) and their partner laboratories and universities called the Joint Aeolus Tropical Atlantic Campaign (JATAC) out of Cabo Verde to validate ESA’s Aeolus satellite. As part of the CPEX-CV – JATAC collaboration in September 2022, the NASA DC-8 carried out coincident underpasses of the Aeolus satellite on four of the thirteen CPEX-CV research flights, performed four overpasses of the ASKOS ground site at Mindelo, and two coordinated flights with the Slovenian WT-10 in situ aircraft that also encompassed a coincident flight under Aeolus and over the Mindelo ground site. Here, we summarize the CPEX-CV science objectives, mission architecture, scientific targets observed on flights flown during the September 2022 campaign, and highlights of the data collected planned to be released to the community in early April 2023 with a focus on collaborative efforts between CPEX-CV and JATAC.
Long-term preservation of geochemical heterogeneities in early Earth: tracking short-lived isotopes in geodynamic models
Authors: Tian Jiacheng , Tackley Paul
Published: February 2023

The short-lived isotope systems, including 146Sm-142Nd (half-life = 103 Ma) and 182Hf-182W (half-life = 8.9 Ma), provide evidence for mantle differentiation events in early Earth, as both the daughter nuclides are more incompatible than the parent nuclides. For the 146Sm-142Nd system, both positive and negative μ142Nd measurements are observed in Hadean-Archean mantle-derived rocks, which possibly indicates a major differentiation event of the silicate Earth before the extinction of 146Sm (e.g., Boyet and Carlson, 2005, Science). The diminishing trend of μ142Nd between Hadean and Archean, on the other hand, suggests continuous mantle mixing during this period. However, for the 182Hf-182W system, Hadean-Archean mantle-derived rocks often show positive μ182W anomalies followed by a decline in at 2.5~3.0 Ga ago without a mixing trend (e.g., Carlson et al., 2019, Chem. Geol.). Also, μ142Nd and μ182W often show no or negative correlation in Hadean-Archean mantle derived rocks (e.g., Rizo et al. 2016, Geochim. Cosmochim. Acta), which requires a mechanism to decouple these two isotopic systems.In this study, we implement both 182Hf-182W and 146Sm-142Nd system in a global thermochemical geodynamic model, StagYY (Tackley, 2008, PEPI), to track the evolution of these isotope systems through Earth’s mantle evolution. Based on the particle-in-cell method, the geodynamic model incorporates melting and magmatic crust production that allow us to track both fractionation (by melting and crustal production) and mixing (through mantle convection) of trace elements through time. We discuss in detail how (1) the ‘basalt barrier’ at the base of the mantle transition zone (Davies, 2008 EPSL), (2) crustal delamination from intrusive magmatism, or plutonic-squishy-lid tectonics (Lourenco et al., Nat. Geo. 2018; GCubed 2020), and (3) late accretion could affect the tectonics of early Earth, and the preservation of geochemical heterogeneities and decoupling of two isotopic systems in the mantle through time. 
Pliocene climate and the high latitudes: a data/model perspective
Authors: Haywood Alan
Published: February 2023

It is well established that during intervals of the Pliocene epoch climatic conditions were both warmer and wetter than the pre-industrial era. Since the first global compilations of geological proxy data and climate modelling studies, it has been known that the pattern of surface temperature change during the Pliocene was not spatially uniform, with both geological data and models showing an amplification of surface temperature change at higher latitudes. This is a trait which the Pliocene shares with other warm(er) climate states in Earth history. Over the last two decades our appreciation of the character of climate and environmental change in the high latitudes has evolved significantly with (a) the availability of new and multi-proxy reconstructions, and (b) through the application of different climate, vegetation and ice sheet models, methodologies and intercomparison projects (PlioMIP1 and 2 and PLISMIP). We have become increasingly aware of the complex interaction of different sources of uncertainty (in proxies, models, model boundary conditions and forcings) when assessing the degree to which climate models are able to reproduce the magnitude of climate change indicated by geological data. It is clear that broad and simple assumptions cannot be made regarding the efficacy of either proxy reconstructions or climate model simulations for the Pliocene high latitudes, and that the picture of Pliocene climate at the higher latitudes, and how well models simulate it, is a nuanced one.Whilst modelling studies have tended to agree in demonstrating the primacy of greenhouse gas forcing on Pliocene warming as a global average, it is increasingly apparent how important other factors such as palaeogeography and ice-sheet reconstructions can be in determining the local and regional pattern of climate change in the high latitudes. Yet, at present many of these aspects remain poorly constrained.Energy balance analyses have demonstrated the importance of clear sky albedo, cloud albedo and heat transports in determining the degree of warming at the high latitudes in climate models. This has helped to inspire new climate modelling studies using perturbed physics in order to explore model uncertainty. However, our focus has largely been on the assessment of the ability of climate models to simulate mean annual temperature change, rather than the seasonal expression of temperature change. Recent work has demonstrated that a large ensemble of climate models is generally able to simulate warm season temperatures in the high latitudes of the Northern Hemisphere, with the apparent discrepancy in mean annual surface temperatures being driven largely by climate models underestimating the magnitude of warming during the cold season. If this is true, it would place a useful additional constraint on how Pliocene climate simulations need to evolve in order to match proxy reconstructions more closely. 
New developments in techniques for the sampling and analysis of atmospheric 14CO2 and 14CH4 at ETHZ and UNIBE, Switzerland
Authors: Szidat Soenke , Laemmel Thomas , Geissbühler Dylan , Rowan Sarah , Gautschi Philip , Lechleitner Franziska , Wacker Lukas
Published: February 2023

Radiocarbon (14C) measurements of atmospheric greenhouse gases such as carbon dioxide (CO2) and methane (CH4) are central in our capability to identify their provenance. The 14C content of these gases provides more insight into the age of their sources and mainly allows the distinction between fossil and modern ones. 14CO2 measurements can be used to analyze the nature of anthropogenic emissions (mostly fossil), or to discern on what organic matter pool respiration is taking place in a given environment. 14CH4 can also be used to detect anthropogenic emissions (from leaks of natural gas, for example) as well as natural emissions produced by methanogenesis, for example from ruminants or in wetlands.The 14C analysis of atmospheric gases is made challenging due to their usual low concentration. Thus making the use of appropriate sampling methods, preconcentration and extraction techniques necessary to reach a sufficient amount of carbon for Accelerator Mass Spectrometry (AMS) analysis. We propose here a general view of the techniques that were developed at the Laboratory for Ion Beam Physics (ETHZ, Zurich), and at the Laboratory for the Analysis of Radiocarbon with AMS (UNIBE, Bern) for the purpose of analyzing CO2 and CH4 in atmospheric samples. We then discuss the practicability and the potential bias introduction of each of them.The techniques are as follows :Automated Graphitization Equipment with Automated Loading Facility (AGE-ALF)
Automated Graphitization Equipment with Cryogenic Trap (AGE-CT)
Methane Preconcentration and Purification System (MPPS)
Generally, samples were collected in sampling bags, either in 5-15L capacity for CO2 or larger than 60L for CH4. Types of samples that are considered are atmospheric CO2 and CH4 samples, CO2 from soil respiration, and CO2 from cave air. The different techniques are presented, and 14C results from standard gases are compared between the extraction lines and two MICADAS AMS systems at ETHZ and UNIBE.
How useful is the initial Pb composition of magmatic allanite ?
Authors: Skrzypek Etienne , Gallhofer Daniela , Hauzenberger Christoph , Haas Isabella
Published: February 2023

Allanite-group minerals are known to incorporate not only U and Th but also initial, non-radiogenic Pb. Allanite can therefore be analyzed in order to assess its crystallization age as well as the ambient Pb composition at the time of crystallization. Whereas allanite age dating has been the focus of many studies, constraining its initial Pb composition has received much less attention. We collected a series of Phanerozoic, allanite-bearing magmatic rock samples (volcanic, plutonic, pegmatite) and measured both the age and initial Pb composition of allanite by laser ablation-multi collector-inductively coupled plasma-mass spectrometry. We show that allanite data can be corrected for mass bias and fractionation using zircon (for U/Pb and Th/Pb ratios) and glass (for Pb/Pb ratios) as reference material as long as allanite is not metamict. A lower intercept age and y-axis intercept Pb composition can be determined by linearly regressing U-Pb data in a Tera-Wasserburg diagram, and a 230Th disequilibrium correction is highly recommended. We find a good agreement between our allanite U-Pb dates and published U-Pb zircon ages for the same localities. Our initial Pb compositions are validated by a fair agreement with Pb isotopic data measured on co-genetic feldspars from the same samples. The initial Pb composition of samples ranging from ca. 530 to 18 Ma reveals fluctuations in initial 207Pb/206Pb ratio, which points to different degrees of crustal (elevated μ=238U/204Pb) contribution. These variations could be due to post-magmatic deformation, weathering or metamorphism, but we believe that they rather reflect differences in initial magma composition. We thus emphasize the usefulness of allanite initial Pb compositions to discuss the source of igneous rocks.
The value of cross-disciplinary approaches for plant water uptake modelling
Authors: Dubbert Maren , Couvreur Valentin , Kübert Angelika , Holz Maire , Werner Christiane
Published: February 2023

In recent years, research interest in plant water uptake strategies has significantly grown in many disciplines such as hydrology, plant ecology and ecophysiology. Quantitative modelling approaches to estimate plant water uptake and the spatio-temporal dynamics significantly advanced from different disciplines across scales. Despite this progress, major limitations, i.e. to predict plant water uptake under drought or it´s impact at large-scales remain. These are less attributed to limitations in process understanding, but rather to a lack of implementation of cross-disciplinary insights in plant water uptake model structure.The main goal of this presentation is to highlight how the 4 dominant model approaches, e.g. Feddes approach, hydrodynamic approach, optimality and statistical approaches, can be and have been used to create interdisciplinary hybrid models enabeling a holistic system understanding that e.g. embeds plant water uptake plasticity into a broader conceptual view of soil-plant feedbacks of water, nutrient and carbon cycling or reflects observed drought responses of plant-soil feedbacks and their dynamics under e.g. drought. Specifically, we provide examples of how integration of Bayesian and hydrodynamic approaches might overcome challenges in interpreting plant water uptake related to e.g. different travel and residence times of different plant water sources or trade-offs between root system optimization to forage for water and nutrients during different seasons and phenological stages.
Modelling the kinematic evolution of valley-scale folding in surge-type glaciers using Elmer/Ice
Authors: Young Erik , Flowers Gwenn , Jiskoot Hester , Gibson Daniel
Published: February 2023

Glacier surges produce iconic valley-scale folds which encode a history of polyphase deformation resulting from switches between quiescent and surging flow. The folding is passive, resulting from disturbances to ice foliation during surging flow, and subsequently altered during quiescent flow. We investigate the kinematic evolution of these kilometre-scale folds, using Elmer/Ice, by modelling folds through multiple surge cycles using idealized synthetic glacier confluence configurations, and identifying how differences in glacier flow regimes imprint themselves onto three-dimensional fold geometry. The surge and quiescent phases are simulated by changing the basal conditions of one of the tributaries, and matching the scale of velocity variations observed in temperate glacier surges. We determine fold geometry using a particle tracking algorithm applied to the modelled velocity fields, where, mimicking a medial moraine, vertically-spaced particles are injected at the flow unit confluence and advected downglacier. Using structural analysis of the model outputs, we present an archetype of kinematic evolution that describes the transition from cylindrical, vertically plunging, gentle folds emplaced during the surge phase, to complex, non-cylindrical, depth-varying folds following multiple cycles of surging and quiescent flow. The initial fold geometry is controlled by longitudinal and lateral shear stress regimes during surging, while fold evolution is governed primarily by lateral shearing after emplacement. We examine the sensitivity of fold geometry to valley geometry, glacier dynamics, and mass balance. Finally, we illustrate the potential of our approach to reconstruct more complex fold geometries as observed in nature, by applying it to a large surge-type glacier in the St. Elias Mountains of Northern Canada.
Deformation and metamorphic evolution of Chotanagpur Gneissic Complex (CGC), East Indian Shield
Authors: Kundu Subha , Tiwari Sudheer Kumar
Published: February 2023

Formation and Evolution of different rock types during growth of Indian shield and mobile belts gives us opportunity to understand tectono-metamorphic implications of Indian subcontinent in Precambrian time. CGC is one such well-preserved fold belt formed during Proterozoic time period which serves valuable knowledge about the evolutionary history of Peninsular India through its rock record. It is located in the eastern part of Indian subcontinent and vastly occupied by Precambrian granite gneiss. From our field observation along Purulia shear zone (PSZ) and published data from different parts of CGC, we observed six stages of deformational and metamorphic evolution based on overprinting relationship of deformation, metamorphic and igneous intrusions.During stage-I, oldest 1870 Ma Ultra High Temperature (UHT) Metamorphic event (M1) happened and it is observed in form of granulite enclaves in E and SE regions of CGC. In stage-II, high-grade metamorphism (M2) defines by regional UHT metamorphism and partial melting of supracrustals during collisional orogeny that causes formation of migmatitic charnockite gneiss by intrusion of granitoid into older M1 granulites. In Northern part of CGC gray granites (porphyritic) intruded into unknown felsic basement with pelitic/calc-silicate supracrustals at 1750-1660 Ma. In this stage S1 gneissic band developed in the regionally extensive gneisses during D1 deformation. Stage-III is defined by post-D1 magmatism where gabbro-anorthosite, porphyritic granitoid, syenite within ∼1650 Ma high grade basement gneiss intruded at ~1550-1500 Ma. In Stage-IV, Paleoproterozoic basement along with the post D1 intrusive deformed under granulite facies metamorphism (M3) in continent-continent collisional setting causes development of regional thin gneissic banding (S2) along E-W related to D2 and D3 deformations during 1000–950 Ma. Stage-V is defined by Post- D3 Intrusion of nepheline syenite, alkali syenite, porphyritic granite and mafic dyke during rifting stage of Grenvillian basement crosscutting all the preexisting fabrics during 950-900 Ma. Stage-VI is defined by upper amphibolite-facies metamorphism (M4) to produce amphibolite, foliated granite and augen gneiss. Pegmatite & leucogranite emplaced parallel to the axial planes of F1-F3 folds interpreted from the mafic dykes in the eastern part of CGC. This causes development of the S3 fabric in N-S orientation overprinted early granulite fabrics because of dominant F2 folding indicates strong E-W compression during 850-780 Ma & 870-780 Ma.
Compilation and processing of bathymetric data recorded along the Northwest African continental margin over several decades
Authors: Tang Qinqin , Schneider von Deimling Jens , Geersen Jacob , Krastel Sebastian
Published: February 2023

The Northwest (NW) African continental margin is well known for the occurrence of large-scale submarine landslides with prominent scarps exposed at the seafloor. Previous studies primarily focused on major landslides, but rarely covered small scarps. It is unclear if the distribution of landslides along the NW African continental margin is biased by the availability of processed data because data were collected mainly in designated surveys in areas of special interest. Numerous multibeam bathymetric data sets, however, are available for the area as data were also collected during transits and cruises where seafloor mapping was not a primary objective. We compiled such various datasets in the open-source MB-System software and implemented a cloud-based auto-processing and adaptive filtering workflow to handle the large bathymetric datasets (15,476 survey lines). The results show that our auto-processed bathymetric data provide a much-improved view of the seafloor (50 × 50 m), compared to EMODnet2020 and GEBCO 2022 GRID without having manually edited the data. Such a workflow allows to process large underway multibeam datasets of the given kind and therefore it resolves the unknown submarine landforms. Our results from NW Africa offer not only new insights into small-scale submarine landslides but also fulfill the missing piece from previous studies that focused on large-scale submarine landslides. Minor scarps are mainly found close to areas with major landslides, supporting the hypotheses that the NW African continental margin is characterized by large-scale but infrequent landsliding. Minor scarps are additionally identified in some other areas, such as the walls of the Agadir Canyon. Associated landsliding may contribute to the well-known Moroccan Turbidite System. The additional information on minor scarps allows us to gain a more comprehensive understanding of submarine landslides and the associated tsunami risk along the NW African continental margin.
Water and nutrient sources in a short stream reach
Authors: Wachniew Przemyslaw , Szostak Radosław , Zięba Damian , Zimnoch Mirosław
Published: February 2023

This work stems from several years of research conducted in a medium size lowland catchment of the groundwater-fed Kocinka River in Poland that aimed at quantification of sources and transformations of nitrate pollution. Deconvolution of nitrate sources and transformations at the catchment scale appeared to be difficult because of the mostly diffuse character of groundwater inflows with diverse concentrations of nitrate. Additionally, the hydromorphological characteristics that may affect riverine nutrient cycling change significantly along the river. Therefore, a short, 2.6 km long reach of the upper Kocinka was selected for a more detailed study. This reach is representative of small, channelized streams in urbanized rural areas that receive loads of nutrients and other contaminants from various, often episodic, sources such as farmyard, urban and road runoff, sewage and wastewater disposal, fish ponds. Isotopic compositions of water and nitrate. temperature of water as well as drone-based thermal images were used to characterize sources of streamflow and nitrate. Tracer experiment with tritium and the radioactive phosphorus isotope (32P) provided insights [1] into the significance of transient storage zones in solute transport and the extent of phosphorus removal.The research has been partially financed from the funds of the "Excellence Initiative - Research University" program at AGH University of Science and Technology.[1] Zieba, D., & Wachniew, P. (2021). Phosphorus Transport in a Lowland Stream Derived from a Tracer Test with 32P. Water 2021, 13, 1030. 
The polarisation state of transionospheric radio waves detected by RRI on Swarm-E
Authors: Pandey Kuldeep , Gillies Robert G. , Kalafatoglu Eyiguler E. Ceren , Hussey Glenn C. , Danskin Donald W. , Yau Andrew W.
Published: February 2023

The Radio Receiver Instrument (RRI) on-board the Swarm-E satellite is used to determine the full polarisation state of transionospheric radio waves. Co-ordinated experiments between ground transmitters and RRI have shown that the detected radio waves can have ellipticity that varies from linearly to circularly polarised when observed poleward of the transmitter at low elevations. Circular polarisation states are expected for waves propagating traverse to the local geometric field; however, these circular states were observed over a much wider range of aspect angles than expected. The present study compares the results of radio transmissions from the Saskatoon SuperDARN radar with a transionospheric radio wave model to estimate the relative strengths of received O- and X-mode waves along the satellite track. At selected low elevations, the X-mode of the radio wave dominates over the O-mode, resulting in a circular ellipticity, although the propagation is not transverse to the magnetic field. This work presents new ways to utilize ellipticity polarisation observations of radio waves to better understand the structure of the ionosphere, complementing Faraday rotation observations which have been extensively used.
Mycorrhizal guild interactions, rather than the Gadgil effect, slow decomposition of mor-layer humus
Authors: Mielke Louis , Klein Julien , Ekblad Alf , Finlay Roger , Lindahl Björn , Clemmensen Karina
Published: February 2023

Boreal forest soils are dominated by three fungal guilds; ectomycorrhizal fungi associated with canopy-forming trees, ericoid mycorrhizal fungi associated with understory shrubs and free-living saprotrophic fungi. We followed decomposition of pine needle litter and mor-layer humus in a factorial pine root exclusion and shrub removal experiment in a mature pine forest over three years to evaluate fungal guild effects on mass loss. Litter mass loss was 10% faster when ectomycorrhizal fungi were excluded, however this ‘Gadgil effect’ was only found in one of two litter sets, and it was independent of shrub presence. In contrast, humus mass loss was hampered by shrub presence and promoted by ectomycorrhizal fungi, although presence of both guilds resulted in the largest humus mass remaining. This suggests that saprotrophic-ectomycorrhizal interactions are of little significance for early-stage litter decomposition, while ericoid and ectomycorrhizal guilds interact to determine late-stage organic matter balance in boreal forest soils.
Simulating the terrestrial biosphere in the high CO2 world of the early Eocene
Authors: Brugger Julia , Thompson Nick , Utescher Torsten , Salzmann Ulrich , Hickler Thomas
Published: February 2023

The early Eocene is a warm period suitable for studying the influence of high atmospheric CO2 concentrations on climate, the terrestrial biosphere, and their interaction. Here, we simulated the terrestrial biosphere of the early Eocene with a dynamic global vegetation model (LPJ-GUESS), driven by climate input from the Deep-Time Model Intercomparison Project (DeepMIP). We find a strong expansion of tropical and temperate forests to higher latitudes, which is more pronounced when assuming CO2 concentrations at the high end of plausible values. The modeled vegetation distribution is compared to a recently compiled extensive early Eocene paleobotanical global dataset. Simulated and reconstructed vegetation show good agreement, which improves with higher CO2 concentrations. In contrast to earlier vegetation modeling studies our simulations are able to accurately simulate the expansion of tropical forests under CO2 concentrations larger than 4-times pre-industrial CO2. Given the good agreement between modeled vegetation and paleobotanical data our simulations allow us to gain a more comprehensive understanding of the early Eocene terrestrial biosphere, including the global carbon cycle and the role of wildfires. In addition, our comparison of modeled vegetation and paleobotanical data is an important test of the performance of the climate and vegetation models used, which are also used to simulate future impacts of climate change.
Spectral analysis of residual GRACE and GRACE-FO range accelerations
Authors: Koch Igor , Duwe Mathias , Flury Jakob
Published: February 2023

GRACE and GRACE-FO K-band range-rate post-fit residuals obtained after a common estimation of monthly gravity field coefficients and ancillary satellite parameters represent a complex superposition of different effects. In this contribution, we analyze the component of the residuals that is related to geophysical effects. We low pass filter and differentiate range rate post fit residuals to obtain residual range accelerations. A spectral analysis of globaly gridded residual range accelerations reveals unmodeled signal related to (ocean) tides and hydrology. The time series with approximately 100 millios of data records allows us to identify main periodic contributors in different bands. Diurnal and semi diurnal signal can be resolved on a 5x5 degree grid, while periods of 5 and 3 hours can be resolved on a 7.5x7.5 and 10x10 degree grid.
Exploring the merging potential of high temporal resolution and high spatial resolution microwave remote sensing data
Authors: Chen Yueli , Ludwig Ralf
Published: February 2023

Microwave remote sensing can provide effective monitoring of landscape FT dynamics. Its sensitivity to surface permittivity, which is predominantly influenced by the phases of water, can be used to measure landscape freeze/thaw state information. The technique of Interferometric Synthetic Aperture Radar (InSAR) enables to map the ground movement through the use of Synthetic Aperture Radar (SAR). Compared to optical imagery, microwave data has advantages that it would not be affected by cloud cover, smoke or daylight and exhibits useful penetration depths of soil and vegetation.  Both active and passive microwave remote sensing with different wavelengths have shown their principal capacity in many studies and have complementary advantages to each other. While many passive sensors (such as SMAP and SMOS) are providing observations with high temporal resolution and good worldwide coverage at the deca-kilometer scale, there are a series of active sensors providing observations with worse temporal resolution but much better spatial resolution at the scale from a few meters to a few deca-meters, for example, the Sentinel-1 mission from the European Space Agency (ESA) with 5 x 5 m spatial resolution and 6-12 days repeat cycle. Hence, the combined use of different microwave data can be expected further to promote the monitoring of permafrost-related phenomena and permafrost-dominated landscapes.An assumption of near-linear relation between the measurements from the passive and active sensors has been used in NASA’s Soil Moisture Active Passive (SMAP) active-passive baseline algorithm for downscaling coarse-resolution radiometer brightness temperature (TB) using high-resolution radar backscatter (σ 0). Recent research proved that a good linear relationship could be found at a global scale (Zeng et al., 2021). However, the relation is significantly affected by environmental factors, for example, the density of vegetation cover. Based on the findings, we attempt to explore the possibility of merging microwave remote-sensing data from different platforms in this work. We are committed to exploring suitable data sources for merging, as well as the possibility of taking environmental factors into consideration. The capacity and limitation of the merging process will be discussed.    
A Lagrangian View to the Evolution of Convective Updrafts
Authors: Hutton Thomas , Thuburn John , Beare Robert
Published: February 2023

The representation of cumulus convection is a known source of uncertainty within current weather and climate models. Where model resolution is too coarse to accurately resolve convection, parameterisations are required to estimate the impact of small-scale convective processes. High resolution large eddy simulations (LES) can be used to diagnose many aspects of convective processes, such as heat and momentum budgets and rates of entrainment. However, LES is computationally expensive, making it impossible to use within operational models. This study aims to bridge the gap between current coarser models and LES by developing a stochastic Lagrangian model to represent an ensemble of air parcels. Vertical velocity, liquid water potential temperature, and total specific humidity are predicted following the ensemble of parcels. The random motions associated with turbulence are represented by a stochastic term within the w-tendency equation. The mean fields which the parcels interact with are defined by an ensemble average of nearby parcels. Several fixers have been developed to ensure that conservation properties are respected. At the current stage of development, the model can represent dry convective boundary layer and shallow convection cases. A theoretical study of the stochastic differential equations is useful to verify the self-consistency of the model and also as a tool for calibrating various parameters within the model. A key question for this project is how well the stochastic parcel model can replicate the statistics of LES results. This will act as a measure of the model’s success, allowing for a deeper understanding on accurately modelling convective processes. Due to the Lagrangian nature of the model, analysis can be conducted upon how the parcels’ characteristics change over time as the parcels experience smaller-scale convective processes such as entrainment. Ultimately, results from this model may yield better understandings of small-scale convective processes. This can create potential for improvements to parameterisations in operational models, reducing model uncertainty generated by convective processes.
Plasma turbulence within cometary plasma environments
Authors: Pucci Francesco , Behar Etienne , Henri Pierre , Simon Wedlund Cyril , Ballerini Giulio
Published: February 2023

We present a numerical work in which the interaction between a comet and the solar wind is studied in 2D in the plane perpendicular to the solar wind mean field direction. Our simulations are conducted with the hybrid Particle-in-Cell (PIC) code Menura that allows for the injection of a turbulent solar wind [1].First, we consider the case of laminar solar wind and we present a study on the equivalent Mach number of the two-ion-species (cometary and solar wind) plasma surrounding the comet. We develop an expression for the Mach number having suitable limits in the two asymptotic cases of infinite cometary and solar wind ion density; our expression is derived by extending previous studies on bi-ion plasma models [2]. Through numerical simulations in which the cometary activity is varied, we show how our Mach number is able to unambiguously describe  the existence and location of the cometary shock.Second, we compare two runs, one with a laminar and one with a turbulent solar wind in the case of moderate cometary activity. We divide the simulation domain into the regions upstream and downstream the cometary shock. We analyze how plasma turbulence properties are affected by the passage through the shock in the case of a turbulent solar wind. Then, we divide the downstream region into three different regions identified by different solar wind-to-cometary ion density ratios. We study the downstream turbulence properties in the case of laminar and turbulent impinging solar wind and how they vary in those regions. [1] Behar, E., Fatemi, S., Henri, P., & Holmström, M. (2022, May). Menura: a code for simulating the interaction between a turbulent solar wind and solar system bodies. In Annales Geophysicae (Vol. 40, No. 3, pp. 281-297). Copernicus GmbH.[2] Dubinin, E. M., Sauer, K., McKenzie, J. F., & Chanteur, G. (2002). Nonlinear waves and solitons propagating perpendicular to the magnetic field in bi-ion plasma with finite plasma pressure. Nonlinear Processes in Geophysics, 9(2), 87-99.
Are ongoing SUDS design and management routines considering public perception?
Authors: Zubelzu Sergio , Cuevas Blanca , Bernal Carlota , Esteve Paloma , Gómez María Teresa , López Jesús , Rodríguez Leonor
Published: February 2023

SUDS were initially conceived for mimicking hydrological original conditions of urban catchments. SUDS have been strongly promoted by public and private decision-makers around the world. Public perception has been previously addressed by different studies many studies in a disconnected manner and at different planes. Similarly, the social benefits have also been studied from different perspectives mostly enhancing local perspectives not clearly comparable between territories. In this work we present the initial literature review on SUDS social aspects and public perception. We find from the previous studies that a general method for both making society aware of SUDS aims and roles and providing designers and planners with public perception is clearly lacking. We seek to highlight the gaps to be filled with further analysis and studies so public society can be completely engaged in SUDS design and operation.