bluuebunny/crossref_metadata_2025 huggingface dataset:
Extreme Compound Events of Air Pollution and Effects on European Mediterranean Cities
Authors: Sánchez-Jiménez Francisco , Raluy-López Eloisa , Segado-Moreno Leandro , García-Fernández Ester , Montávez Juan Pedro , Jiménez-Guerrero Pedro
Published: February 2023

Air pollution is a significant concern for society due to its negative impact on human health. The ability to forecast pollutant concentrations and predict extreme pollution events is essential for mitigating their harmful effects. These events are commonly presented as compound and can have serious consequences (Zscheischler et al., 2020) for public health, making it important to identify and understand the variables that contribute to them.In this study, we used state-of-the-art techniques based on artificial intelligence and machine learning methodologies to analyze data from a selection of European Mediterranean cities in order to identify the meteorlogical and preceding pollution variables that best explain extreme pollution events involving PM10, O3and NO2. Furtheremore, the role of the combined effect of these variables and recent climatic conditions is also examined on excess mortality rates using the likelihood multiplication factor parameter (Ridder et al., 2020) as well as the importance given by Random Forest Regression  Models.Our results show that these events show a clear compound nature, understanding the non-linearity changes in the intensity of compound events. The main driver factors depend on the pollutant specie as well as the season of the year. ReferencesRidder N. N., Pitman A. J., Westra S., Ukkola A., Do H. X., Bador M., Hirsch A. L., Evans J. P., Di Luca A., Zscheischler J. (2020). Global hotspots for the occurrence of compound events. Nature communications 11(1), 1–10.Zscheischler J., Martius O., Westra S., Bevacqua E., Raymond C., Horton R. M., van den Hurk B., AghaKouchak A., Jézéquel A., Mahecha M. D., et al. (2020). A typology of compound weather and climate events. Nature reviews earth & environment 1(7), 333–347.
Reconstructing forest dynamics in the European Alps through a high-dimensional analysis based on Landsat time series
Authors: Morresi Donato , Maeng Hyeyoung , Marzano Raffaella , Lingua Emanuele , Motta Renzo , Garbarino Matteo
Published: February 2023

Natural disturbances are increasingly threatening forest ecosystems due to climate change globally. InEurope, disturbance regimes have intensified over the last decades, leading to increased size, frequencyand severity of disturbance events. Satellite remote sensing data acquired over the past decades are crucialfor assessing changes in disturbance regimes as they provide wall-to-wall spatial information from thelandscape to the global scale. In particular, Landsat imagery has been continuously acquired since 1984,and it offers an unprecedented opportunity for mapping land cover changes thanks to its spatial andspectral consistency. Following the opening of the USGS Landsat archive, dense time series have beenexploited through automated algorithms for targeting forest dynamics. Currently, the most widely usedalgorithms aim to detect abrupt and gradual changes by performing a temporal segmentation of Landsattime series at the pixel level. The sensitivity of automated algorithms has been enhanced by includingmultiple spectral and spatial information in the time series though their combined usage is still limited.Here, we present an automated algorithm for detecting forest dynamics named High-dimensional detectionof Land Dynamics (HILANDYN), which exploits the temporal, spatial and spectral dimensions of inter-annualLandsat time series. We tested HILANDYN to map forest disturbances that occurred during the last fourdecades in the European Alps. HILANDYN builds upon a statistical procedure for detecting changepoints inhigh-dimensional time series through a bottom-up segmentation procedure. Our results showed that thealgorithm is sensitive toward a wide range of disturbance severities and can detect stand-replacing events,e.g. windthrows and wildfires, and non-stand-replacing ones, e.g. insect outbreaks and drought-induceddieback. Moreover, we were able to map disturbances occurring in consecutive years, such as windthrowsfollowed by salvage logging. We obtained the best results in terms of accuracy metrics using a combinationof original bands and indices that included the heterogeneous spectral information provided by themultispectral sensors of the Landsat missions. In particular, we achieved an F1 score equal to 83% for thedisturbed class, corresponding to a user’s accuracy of 84,3% and a producer’s accuracy of 82%. Accuratedisturbance maps of the European Alps will enable a thorough analysis of the shifts in the disturbanceregimes over the last four decades, alongside the assessment of forest recovery patterns under differentmanagement practices and environmental conditions.
A Swarm-only night-side magnetospheric model to degree and order 3
Authors: Gomez Perez Natalia , Beggan Ciaran
Published: February 2023

The Swarm mission, launched in November 2013, consists of three identical satellites in near polar orbit dedicated to measuring the Earth's magnetic field to very high accuracy. Two satellites fly at a lower altitude in close orbital proximity while the third flies at a higher altitude producing a steady local time drift. The unique configuration allows a wide set of new models of the various sources of the field to be created from core to magnetosphere. In this study, we separate the magnetic field sources measured at satellite altitude and produce a model of the night-side magnetosphere. This model can be used to study the magnetosphere during storm time to see how it responds to external forcing. Additionally, we observe seasonal variations of the quiet-time configuration. We find good agreement with previous studies during both quiet and storm periods, and we are able to produce these complete models in a timely fashion, making a high-resolution and near real-time characterisation of the magnetosphere configuration possible.
Relationship between coseismic ground deformation and geological structures associated with the 2016 Mw 6.5 central Italy earthquake
Authors: Porreca Massimiliano , Carboni Filippo , Cenci Giacomo , Occhipinti Martina , De Luca Claudio , Valerio Emanuela , Massimiliano Rinaldo Barchi , Ercoli Maurizio
Published: February 2023

In the last three decades, remote sensing techniques, such as Differential Synthetic Aperture Radar Interferometry (DInSAR), have been exploited for investigating, with high accuracy, ground displacement phenomena. Large seismic events can trigger deformations at the surface, which are controlled by the active faults and the intercepted lithologies.
In 2016-2017, a long earthquake sequence struck the Apennines in central Italy, producing impressive surface ruptures attributed to the 24 August Mw 6.0 and 30 October Mw 6.5 mainshocks. These ruptures were investigated and mapped by field geologists soon after the earthquakes, and during the following years also by remote sensing data.

We present detailed maps of the surface deformation pattern produced by the M. Vettore Fault System (VFS) during the October 2016 earthquakes. The DInSAR analysis has been retrieved from ALOS-2 SAR data, via the Parallel Small BAseline Subsets (P-SBAS) algorithm. At the local scale, we identify a large number of surface ruptures, most of which already observed in the field. At the large scale, we trace a set of five geological cross-sections to inspect a possible link between the coseismic vertical displacement, the lithology distribution and the tectonic structures of the area (i.e., thrusts, normal faults). On these sections, we also project the seismicity distribution recorded during October 2016.

The integration of such datasets allows the recognition of an important geological control in the overall distribution of the deformation, which shows maximum values in correspondence of the carbonatic multilayer and minimum values within the clastic succession. The distribution of seismicity allows also us to distinguish seismogenic by aseismic slip associated with fault ruptures.

Along the sections, we observe a typical long-wavelength convex curvature of the subsiding block, not directly recognizable in the field.  In the area of maximum subsidence, this curvature is interrupted by an anthitetic fault at which is not associated with any seismicity. In addition, we observe that further deformation is localized at the footwall of the VFS, corresponding to the hangingwall block of an important thrust fault, where shallow seismicity was also recorded. Here, we observe that the coseismic deformation tends to decrease toward the outcropping thrust. In the south sector, instead, we do not observe a control of regional thrusts acting as a barrier to the deformation.

The results of this work demonstrate that the integration of surface geology, remote sensing data and seismicity, can lead to a better understanding of the influence of geological structures on the distribution of the surface deformation associated with earthquakes.
The impact of landscape and land use changes on the critical zone and society: the Belmont Forum ABRESO project
Authors: Richiardi Chiara , Adamo Maria , Scartazza Andrea , Sella Lisa , Baneschi Ilaria , Botteghi Serena , Brugnoli Enrico , Fuina Silvana , Gavrichkova Olga , Maerker Michael , Mattioni Michele , Ragazzi Elena , Rossi Valentina , Rota Francesca Silvia , Salvadori Matteo , Tarantino Cristina , Vicario Saverio , Zanetti Alberto , Pennisi Maddalena
Published: February 2023

The stable presence of humans in the Alps dates back to the Bronze Age and peaked in the mid-19th century, deeply shaping the landscape and allowing the co-evolution of numerous plant and animal species. Since the 1950s, socio-economic changes have led to the gradual depopulation of mountain areas, and the consequent abandonment of traditional agro-pastoral activities. The rupture of the long-established balance between man and nature has triggered a process of transition, further exacerbated and accelerated by climate change. The Belmont Forum project ABRESO (Abandonment and rebound: Societal views on landscape and land-use change and their impacts on water and soils) started in 2021 and aims at advancing the understanding of mitigation and adaptation strategies to environmental change, through an international partnership involving five countries (the United States, France, Italy, Japan and Taiwan). Italy contributes to the project with three case studies: Gran Paradiso National Park, Val Grande National Park and the Tesino highlands are investigated in the Italian Alps. Using an interdisciplinary approach, the project aims to study the impact of the abandonment of traditional activities on ecosystem services provisioning, such as biodiversity conservation and soil sustainability, as well as the actual perception of the ongoing environmental changes by different stakeholders and its subsequent integration into local land management practices and policies. The land use and land cover change occurring due to land abandonment can have profound implications in the critical zone (CZ), inducing changes in soil, vegetation, carbon fluxes and water resources. This project integrates the natural and social sciences approaches to study the evolution of ecosystems in response to these factors. More specifically, advanced techniques that integrate Earth Observation, biogeochemical analyses and socio-economic investigation are used in the Italian sites to understand in which extent geo-biophysical and social landscapes reciprocally interact. The environmental variables collected for ecosystem monitoring and to study and upscale the ongoing dynamics in the CZ include snow cover and phenology parameters, soil organic carbon, and land use change maps extracted from time series of satellite imagery, validated via in situ measurements. Then, the observed processes will be compared to the perception of different stakeholders (local population, policy makers, tourists, business keepers, etc.) to unveil new insights into the way land use change in the mountain areas influence and is influenced by the local land management practices and policies.
Active Tectonics in Southern Haiti and Surface Rupture of the 14 August 2021 Earthquake
Authors: Saint Fleur Newdeskarl , Klinger Yann , Dessable Joseph Emmanuel , Saint-Preux Germain , Feuillet Nathalie , Boisson Dominique , Calais Eric , de Chabalier Jean-Bernard
Published: February 2023

The 14 August 2021 earthquake occurred along the southern peninsula of Haiti only 11 years after the 12 January 2010 devastating earthquake. According to seismological and geodetic data, the events are both complex involving more than one fault. The 2021 rupture mainly portrayed reverse motion to the east near L’Asile town and left-lateral strike-slip motion to the west near Camp-Perrin town and Macaya mountain. A few days after the 2021 event, we conducted the first post-seismic field reconnaissance along the left-lateral Enriquillo-Plantain Garden Fault (EPGF) zone from L’Asile to Macaya mountain. We found numerous fresh cracks and landslides along that fault zone. The 111 cracks are mainly E-W-striking, some are oriented WNW-ESE, consistent with fault orientation in the area. In addition, the biggest cracks are mostly located to the west of the rupture zone, some of them may be potential fault surface rupture as revealed by seismological data. Furthermore, our observations along the northern coast of the southern peninsula revealed no significant coseismic coastal uplift as also suggested by InSAR data. Besides that field reconnaissance, we revisited the fault map around the epicentral area using high-resolution LiDAR data, Pléiades imagery and aerial photographs. We identified several left-lateral offsets of tens of meters corresponding to successive slips along the EPGF from L’Asile to Macaya mountain. In addition to the strike-slip deformation, we identified numerous geomorphic features related to long-term tectonic uplift to the north of the EPGF surface trace near the eastern part of the 2021 rupture. Those features are strikingly rare to the south. Such a pattern may indicate that the EPGF is north-dipping in the area. The 14 August 2021 rupture offers a new opportunity to constrain the kinematics and geometry of the EPGF system in southern Haiti.
Elasticity of hydrous olivine at high pressure and seismic detectability of water in Earth's mantle
Authors: Faccincani Luca , Criniti Giacomo , Kurnosov Alexander , Boffa Ballaran Tiziana , Withers Anthony C. , Mazzucchelli Maurizio , Nestola Fabrizio , Coltorti Massimo
Published: February 2023

The dominant phases of Earth’s upper mantle are commonly referred to as nominally anhydrous minerals (NAMs) but may contain significant amounts of water. The colloquial term “water” in NAMs is related to the presence of hydroxyl-bearing (OH-) point defects in their crystal structure, where hydrogen is bound to lattice oxygen and is charge-balanced by cation vacancies. For this reason, the incorporation of even small amounts of water may substantially affect the physico-chemical properties of NAMs, such as their elasticity, rheology, and melting temperature. Olivine is considered the most abundant phase of Earth’s upper mantle and constitutes about 60 vol.% of a primitive upper mantle (pyrolite) phase assemblage. Although natural olivine samples originating from the shallow upper mantle are relatively dry (maximum H2O concentrations of about 400 ppm), a plethora of experimental data indicate that olivine water storage capacity significantly increases to 0.2-0.5 wt.% H2O at deeper upper mantle conditions.In this contribution, we investigated the effect of water on the elastic properties and sound wave velocities of hydrous Mg1.8Fe0.2SiO4 (Fo90) olivine samples with realistic water contents for deep upper mantle conditions with the aim of interpreting both seismic velocity anomalies in potentially hydrous regions of Earth's upper mantle and the observed seismic velocity and density contrasts across the 410-km discontinuity between the upper mantle and the mantle transition zone. To do so, we performed simultaneous single-crystal X-ray diffraction and Brillouin scattering measurements at room temperature up to ~12 GPa on Fo90 olivine with ~0.20 wt.% H2O to constrain its full elastic tensor. Results were complemented with a careful re-analysis of all the available single-crystal elasticity data from the literature for Fo90 olivine to re-determine the elastic behaviour of the anhydrous phase. Our new data show that the sound wave velocities of hydrous and anhydrous olivines are indistinguishable within uncertainties at pressures corresponding to the base of the upper mantle. Therefore, if amounts of water were to be incorporated into the crystal structure of Fo90 olivine, its elastic and seismic behaviour at high pressure would likely remain unchanged. This suggests that water in olivine is not seismically detectable, at least for contents consistent with deep upper mantle conditions. Moreover, the incorporation of water in olivine is unlikely to be a key factor in reconciling seismological observations at the 410-km discontinuity with a pyrolitic mantle, but rather corroborates previous evidence of a deep upper mantle that is less enriched in olivine than the pyrolite model.
Pan-Arctic remotely sensed observation of coastal settlements - recent updates
Authors: Tanguy Rodrigue , Bartsch Annett , Widhalm Barbara , von Baeckmann Clemens , Efimova Aleksandra , Vieira Goncalo
Published: February 2023

Rapid and unprecedented warming of high latitudes exposes Arctic coastal communities to greater vulnerability as they observe their territory changing through general permafrost degradation, episodes of flooding and accelerated coastal erosion threatening their infrastructure and livelihood. Local information is known for infrastructures mapping and coastal changes but consistency in the measurement is lacking as well as spatial coverage for large coastal areas. The need of a consistent circumpolar dataset is primordial in order to map risks and mitigate impacts for arctic coastal communities. Machine learning methods with Sentinel 1/2 imagery allow the circumpolar mapping of arctic coastal settlements (Bartsch et al. 2021a). Validation of recent updates are supported by high-resolution data from the Pleiades satellites, aerial and drone imagery. This study is part of the ESA EO4PAC project which aims to provide a range of satellite derived information, including coastal erosion/accretion and infrastructure in the proximity, for the next generation of the Arctic Coastal Dynamic Database (ACD; Lantuit, et al. 2012).  Previous results highlight the detection of 50% more human presence information than in OpenStreetMap especially in Russia with recent expansion of infrastructures related to expanding oil and gas industry. Recent updates of the SACHI dataset (Bartsch et al. 2021b) will be presented including additional attributes for roads and their validation. A preliminary categorization of settlements with respect to permafrost degradation (based on Permafrost_cci records) and coastal erosion based on the current ACD will be presented.Bartsch, A., G. Pointner, I. Nitze, A. Efimova, D. Jakober, S. Ley, E. Högström, G. Grosse, P. Schweitzer (2021a): Expanding infrastructure and growing anthropogenic impacts along Arctic coasts. Environmental Research Letters. https://doi.org/10.1088/1748-9326/ac3176Bartsch, Annett, Pointner, Georg, & Nitze, Ingmar. (2021b). Sentinel-1/2 derived Arctic Coastal Human Impact dataset (SACHI) (Version 1) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.4925911Lantuit, Hugues; Overduin, Pier Paul; Couture, Nicole; Wetterich, Sebastian; Are, Felix; Atkinson, David; Brown, Jerry; Cherkashov, Georgy A; Drozdov, Dimitry S; Forbes, Donald Lawrence; Graves-Gaylord, Allison; Grigoriev, Mikhail N; Hubberten, Hans-Wolfgang; Jordan, James; Jorgenson, M Torre; Ødegård, Rune Strand; Ogorodov, Stanislav; Pollard, Wayne H; Rachold, Volker; Sedenko, Sergey; Solomon, Steve; Steenhuisen, Frits; Streletskaya, Irina; Vasiliev, Alexander (2012): The Arctic Coastal Dynamics Database: A New Classification Scheme and Statistics on Arctic Permafrost Coastlines. Estuaries and Coasts, 35(2), 383-400, https://doi.org/10.1007/s12237-010-9362-
Using geomojis to communicate geosciences: from development to use
Authors: Shires Claire , van Wyk de Vries Benjamin
Published: February 2023

Communication across linguistic and cultural borders is vital in our globalised but compartmentalised world, where different people from different origins mix and interact. In the context of geological hazards and the geological environment, we are working towards a clear system that enables specialists in different fields to communicate effectively with each other, and for a common system that allows all types of non-specialists (e.g. general public) to communicate as well. This works using symbols and pictograms to represent geological and environmental phenomena and features, for example geohazards, that can be used to communicate clearly and efficiently. Certain hazard symbols are already in use across the globe, such as those for chemical or environmental hazards, or such as 'rock fall' warning signs that are universal. In this project, we focus on the geological environment and geohazards, and much of the work is done within a UNESCO Geoscience Programme project 'Geoheritage for Resilience', using geoheritage sites as sites for communication and testing, and more recently with a Franco-Mexican ECOS exchange project 'Building Sense in Natural Heritage'. Our geological pictograms, or ‘geomojis’, bridge the gap between simple symbols and words, crossing language borders by representing concepts that we have identified as particularly important for understanding geohazards and risk. Our geomojis are linked to the Global Framework for Geology (see Global and Planetary Change, 2018 - https://digitalcommons.mtu.edu/michigantech-p/427), allowing the context of each geomoji in the Earth system to be understood. We are currently running international workshops to promote discussion and test the geomojis that we have created. These workshops have raised new pictographic needs and the problems associated with them. The goal of these workshops is to consolidate geoscience knowledge from different specialisations and create a basic standardised set of symbols for all geological hazards. This standardisation of geohazard symbols could improve communication not only between specialists and non-specialists, but between geologists themselves. The global framework and geomojis help us to think outside the box of our specialist environment. These geo-pictograms can be used for geoscience communication in all forms, from hazard and risk publications to signage at geological sites and in discussions with local populations. They can be adapted and modified for the local context and needs, while providing a central, and global, base for comparison. We plan to use the set of reference geomojis to accompany a multilingual glossary on geological hazard and risk terminology, a project that we hope will help international geoscience communication.
Investigating organic matter lability and hydrology in degrading peatland permafrost, Northern Norway
Authors: Knutson Jacqueline , Clayer François , Dörsch Peter , Westermann Sebastian , de Wit Heleen
Published: February 2023

Due to climate change, the risk of destabilization of soil organic carbon by permafrost thaw has increased dramatically. In many areas, including Norway, permafrost has disappeared entirely which releases stored organic carbon to decomposition and transport. Permafrost regions are estimated to store approximately twice the amount of carbon currently present in our atmosphere and the degradation of these carbon hotspots leads to further emissions of greenhouse gases. Thawing of ice-rich permafrost soils in areas of low relief commonly generates thermokarst ponds, which expose old carbon to degradation and can become hotspots of greenhouse gas (GHG) emissions. These thermokarst pond systems and the surrounding peatlands are hydrologically connected, allowing for the export of organic matter.  

Here we present our investigations of hydrology, water chemistry and dissolved organic matter (DOM) lability from areas of thawing permafrost and the resulting thermokarst ponds in the Iškoras peat plateau, located in a headwater catchment on the Finnmarksvidda in Northern Norway. A 12-30h dark incubation method is used to estimate DOM lability. Between May 2021 and September 2022, we collected water samples and performed dark incubations on 7 occasions from several thermokarst ponds, wetland streams and a lake. These samples were analyzed for nutrients, greenhouse gas (CO2, CH4 and N2O) and O2 concentrations. Greenhouse gas concentrations in the water samples and at the end of the dark incubations were analyzed by gas chromatography following headspace equilibrium. In addition, floating chambers were deployed to measure diffusive CO2 emissions. High frequency water height and temperature sensors were installed in both ponds and streams in autumn 2021. 

A preliminary analysis indicates that the thermokarst ponds are high in concentrations of CO2 and CH4 and are key sources of these gases within the landscape when compared to the wetland stream stations. N2O shows seasonal variability and is likely controlled by vegetative uptake of nitrogen although there is still high production in the thermokarst ponds. CO2 productions rates are highest in the ponds, especially those ponds that are darker in color. These data all highlight the lability of the organic matter originating from the permafrost plateau. We aim to observe the seasonal and spatial changes in the lability of organic matter from the thermokarst ponds and the seasonal hydrological connections between the peat plateau and the surrounding wetlands.
Towards an interoperable digital ecosystem in Earth System Science research
Authors: zu Castell Wolfgang , Bumberger Jan , Braesicke Peter , Frickenhaus Stephan , Kleeberg Ulrike , Kunkel Ralf , Lorenz Sören
Published: February 2023

Earth System Science (ESS) relies on the availability of data from varying resources and ranging over different disciplines. Hence, data sources are rich and diverse, including observatories, satellites, measuring campaigns, model simulations, case studies, laboratory experiments as well as citizen science etc. At the same time, practices of professional research data management (RDM) are differing significantly among various disciplines. There are many well-known challenges in enabling a free flow of data in the sense of the FAIR criteria. Such are data quality assurance, unique digital identifiers, access to and integration of data repositories, just to mention a few. The Helmholtz DataHub Earth&Environment is addressing digitalization in ESS by developing a federated data infrastructure. Existing RDM practices at seven centers of the Helmholtz Association working together in a joint research program within the Research Field Earth and Environment (RF E&E) are harmonized and integrated in a comprehensive way. The vision is to establish a digital research ecosystem fostering digitalization in geosciences and environmental sciences. Hereby, issues of common metadata standards, digital object identifiers for samples, instruments and datasets, defined role models for data sharing certainly play a central role. The various data generating infrastructures are registered digitally in order to collect metadata as early as possible and enrich them along the flow of the research cycle. Joint RDM bridging several institutions relies on professional practices of distributed software development. Apart from operating cross-center software development teams, the solutions rely on concepts of modular software design. For example, a generic framework has been developed to allow for quick development of tools for domain specific data exploration in a distributed manner. Other tools incorporate automated quality control in data streams. Software is being developed following guiding principles of open and reusable research software development.A suite of views is being provided, allowing for varying user perspectives, monitoring data flows from sensor to archive, or publishing data in quality assured repositories. Furthermore, high-level data products are being provided for stakeholders and knowledge transfer (for examples see https://datahub.erde-und-umwelt.de). Furthermore, tools for integrated data analysis, e.g. using AI approaches for marine litter detection can be implemented on top of the existing software stack.Of course, this initiative does not exist in isolation. It is part of a long-term strategy being embedded within national (e.g. NFDI) and international (e.g. EOSC, RDA) initiatives.
Viscosity and thermal pressurization during large seismic slip lead to rateand state phenomenology
Authors: Stathas Alexandros , Stefanou Ioannis
Published: February 2023

In this paper, based on the model of thermal pressurization, we present a new way for the emergence of rate and state phenomenology (RSF, friction law) during the earthquake cycle. In the framework of fault mechanics, the common physical mechanism for the RSF phenomenology is slip and plastic deformation at the asperity contacts. We show that the fundamental physical mechanism of thermal pressurization together with viscosity inside the fault can also reproduce rate and state phenomenology.More specifically, in our numerical analyses we model frictional weakening during large seismic slip due to thermal pressurization inside the fault. We introduce thermo-hydro-mechanical couplings to model thermal pressurization and a first order micromorphic Cosserat continuum, in order to avoid mesh dependence of the numerical results. Moreover, we introduce viscosity in the form of strain rate hardening. When we perform velocity stepping analyses, our numerical findings show that friction presents, initial peak over-strength and frictional oscillations around a residual value (see Figure). Our results, deriving from fundamental modeling assumptions, exhibit rate and state phenomenology, without the need to introduce the physical mechanism of slip at the asperity contacts.Keywords: THM couplings; Viscosity; Cosserat continuum; Tribology; Earthquakes
Following the Plume: Evaluation of UKESM1 simulation of 2014 Holuhraun eruption in a Lagrangian Framework.
Authors: Duncan Eliza , Jordan George , Malavelle Florent , Kim Paul , Jones Andy , Watson-Parris Duncan , Sellar Alistair , Haywood James , Peace Amy , Teixeira João , Kipling Zak , Partridge Daniel
Published: February 2023

Volcanic eruptions provide invaluable natural experiments to evaluate the transport, evolution, and potential impact of sulphate aerosol on clouds in global climate models (GCMs). The 2014 fissure eruption in Holuhraun, Iceland had an emission rate greater than a third of daily global sulphur dioxide emissions at its peak, resulting in significant perturbations to cloud radiative properties across vast swathes on the North Atlantic. Probing the GCM representation of aerosol lifecycle during transport in the volcanic plume, offers a unique insight to improve aerosol source and sink process understanding, which is essential to reducing one of the largest sources of uncertainty in climate modelling - aerosol-cloud-interactions.Using rural aerosol measurement sites with climatologically relevant time series, we first perform a Eulerian evaluation of the UK Met Office Earth System Model (UKESM1) simulation of the volcanic eruption. Both in-situ observations and UKESM1 demonstrate a significant increase in aerosol concentration during the volcanic eruption compared to the climatology (2008-2013). However, the ‘standard’ version of the model fails to replicate the significant growth events associated with new particle formation seen in the observations during the volcanic eruption. A second simulation of UKESM1 with the addition of boundary layer nucleation, which is not included in the standard configuration, accurately reproduces the timing of nucleation events seen during the eruption period. Finally, we utilise a Lagrangian framework, in which HYSPLIT trajectories are calculated for both GCMs and reanalysis data, to analyse the relevant aerosol source and sink processes during transport that drive the differences between modelled and observed aerosol at the measurement sites. 
Inversion for Eigenvalues of Focal Region’s Elasticity Tensor from a Moment Tensor
Authors: Diner Çağrı , Öztürk Feyza , Aktar Mustafa
Published: February 2023

In this talk, a new geometric inversion method is proposed for obtaining the elastic parameters of an anisotropic focal region. More precisely, the eigenvalues of a vertical transversely isotropic (VTI) elasticity tensor of a focal region are obtained, up to a constant, for a given only one moment tensor, with an accuracy depending on the strength of anisotropy. The reason of using only one moment tensor is that although there occurs a lot of earthquakes in the same focal region, the orientation of the sources are similar. Hence one do not obtain independent equations from each earthquake, in order to use it in the inversion of elastic parameters of the focal region. Moreover, this method can be applied for real-time inversion once the moment tensor of an earthquake is evaluated.The inversion method relies on the geometric fact that a moment tensor can be written as a linear combination of the eigenvectors of the anisotropic focal region's elasticity tensor. Then, in the inversion, we use the fact that each coefficient of this unique decomposition is proportional to the eigenvalues of the focal region's elasticity tensor. Two approximations are used in this inversion method; in particular for the potency and for the source orientations.The strength of anisotropy of the focal region determines how accurate these approximations are and hence it also determines the resolutions of the inverted eigenvalues. Because of the anisotropy of the focal region, the errors in the inversion do depend on the orientations of the dip and rakes angles, but not the strike angle since the focal region is VTI. The accuracy of the inversion for the five parameters of VTI are shown on the steographic projection. The results are very promising along some orientations as shown in the figures. The last section of the talk deals with the inversion of eigenvalues, up to a constant, for a given set of moment tensors; not only one moment tensor. It turns out that the best fit corresponds to the average of inversion results obtained for different orientations of the sources.
Seasonal variability and seasonal shifts of suspended sediment transport in large German river system
Authors: Hoffmann Thomas
Published: February 2023

Suspended sediment transport is an integral part of river systems and provides important services for ecological functioning and human use of river channels. Thus, measuring and monitoring suspended sediment is of great importance to understand the implications of suspended sediment transport and to improve sustainable river management. Suspended sediment in the German waterways is monitored at 62 monitoring stations by the German Water and Shipping Authorities staring in the 1960ties. The dataset provides valuable information on the long-term developments of suspended sediment transport in Germany. After the analysis of suspended sediment rating (Hoffmann et al. 2020) and the long-term trend (Hoffmann et al. 2022) based on the extensive suspended sediment dataset, we present first results on the seasonal variation and the seasonal shifts of suspended sediment transport in Germany. The results indicate that river systems in Germany are characterized by strongly differential seasonal behavior despite modest spatial variations of climatic conditions in Germany. These results will be discussed in terms of seasonal shifts during the last 50 years and the expected changes of the sediment regimes in German river systems due to future climate changes. References:Hoffmann, T.O., Baulig, Y., Fischer, H., Blöthe, J., 2020. Scale breaks of suspended sediment rating in large rivers in Germany induced by organic matter. Earth Surface Dynamics, 8(3), 661-678.Hoffmann, T.O., Baulig, Y., Vollmer, S., Blöthe, J., Fiener, P., 2022. Back to pristine levels: a meta-analysis of suspended sediment transport in large German river channels. Earth Surf. Dynam. Discuss., 2022, 1-28.
Fine-scale agricultural fertilizer management promotes global NH3 emission reduction
Authors: Li Geng , Xu Peng , Fung Jimmy C.H.
Published: February 2023

Mitigating NH3 emission from cropland soil is crucial for further improving air quality. Despite crop-specific emission factors (EFs) being provided by several studies, the lack of high-resolution EFs under different human management practices limits the further exploration of global cropland NH3 mitigation potential. Agricultural NH3 mitigation potential varies widely depending on where emissions are released. Thus, comprehensively and systematically assessing impacts on a fine scale is useful when developing strategies to efficiently mitigate the effects of NH3 emission. In this study, we performed several machine learning models on a global NH3 emission factors response dataset to find the relationship between EFs and climate conditions, soil properties, and human management. The random forest (RF) model with an R2 of 0.78 and an RMSE of 0.88 showed the best estimation ability. Our data-driven approach indicated that the EFs were mainly affected by temperature, water input, N placement, crop type, and fertilizer type. The combine-effect of N application rate and temperature need to be further studied since these two variables interacted most in our RF model. Using the RF model, we provided five-arcminute high-resolution NH3 emission factor maps under different management practices. The results showed that under proper management, the global NH3 emission of rice, wheat, and maize production has a reduction potential of 44%, 34%, and 37%, respectively. The effects of different human management practices vary everywhere due to the interaction of environmental conditions and management. Our management-specific EFs can provide insights for fine-scale NH3 emission control.
Are ocean gyres driven by wind stress, surface buoyancy fluxes, or both?
Authors: Bhagtani Dhruv , Hogg Andrew , Holmes Ryan , Constantinou Navid
Published: February 2023

The large-scale ocean circulation is fuelled by a combination of winds and buoyancy (or heat) fluxes acting on the ocean’s surface. Gyres are central features of large-scale ocean circulation and are involved in the transport of many tracers like heat, nutrients, carbon-dioxide and so on within and across ocean basins. Traditionally, the gyre circulation is explained by the relationship between meridional transport and wind stress curl, known as the Sverdrup balance. However, it has been proposed that surface buoyancy fluxes may also contribute to the formation of gyres, although such a theoretical relationship is lacking in oceanographic literature. Through a series of eddy-permitting global ocean model simulations, we aspire to better understand the relative contribution of wind stress and surface buoyancy fluxes on large-scale ocean circulation. We perturb the atmospheric forcing by spatially varying the wind stresses and/or surface buoyancy fluxes, while minimising the associated changes in mixed layer dynamics. We compare perturbed forcing simulations with a control simulation in an attempt to decompose the large- scale ocean circulation into buoyancy and wind-driven components.
Sustainable agriculture discourses in Germany: a comparative analysis of large-scale text data
Authors: Bartkowski Bartosz , Nagpal Mansi , Baaken Marieke , Chan Katrina , Schneider Nina , Sodoge Jan , Madruga de Brito Mariana
Published: February 2023

Agriculture is a prominent topic in sustainability discourses. However, the debate on the context of what constitutes sustainable agriculture remains to be solved. The relationship between agriculture and sustainability is a rather emotionally charged topic. It touches upon central moral issues such as the relationship between people and nature. At the same time, in an era of increasing urbanization, there is growing detachment, particularly of the urban population, from the realities of farming, often leading to romanticizing the past and demonizing modern “industrial” agriculture. This often results in conflicts that are increasingly played out in the political arena, e.g. in the context of bottom-up initiatives such as referenda (e.g. “Biodiversity & natural beauty in Bayern, Germany”) or farmers’ protests (e.g. the protests against nitrate regulations in the Netherlands and Germany). These alternatives reflect public discourses, which seem to exhibit very little overlap. Ultimately, however, these discourses drive agricultural and environmental policy - understanding them is therefore crucial if one wants to understand the continuing failure of sustainability policies.Here we present a large-scale text analysis using text mining tools to compare three discourses on sustainable agriculture: the scientific discourse (based on an analysis of abstracts from peer-reviewed publications on the topic); the public discourse (based on an analysis of newspaper articles); and the professional farming discourse (based on an analysis of articles from agricultural magazines). We collected three sets of data for the topic modelling analyses: scientific articles (6403 abstracts), newspaper articles (7851 full texts) and agricultural magazine articles (2414 full texts). These were subject to BERTopic modelling analysis to generate coherent topic representations. These topics are used to shed light on discourses related to sustainable agriculture with a focus on Germany. We apply topic modelling to identify topics that emerge from each of these three discourses and compare them in terms of prevalence and temporal development. The overarching question is what is being discussed under the label “sustainable agriculture”, how the three discourses differ in this respect and whether there are any signs of interaction or even convergence in terms of discussed topics. We thus provide a unique perspective on a central, heavily contested part of the sustainability discourse.
Response of yield for a deficit irrigated crop rotation system: sensitivity of soil hydraulic parameters
Authors: Fan Xiangyu , Schütze Niels
Published: February 2023

Multiple cropping is an effective measure to increase the intensity of land use. The North China Plain is one of China's most important grain production areas, with 70 % of the arable land under double rotation of winter wheat and summer corn. Soil water flow affects the distribution of irrigation water between the two cropping seasons, as the final soil moisture condition of one season is the initial soil moisture condition of the next season. Therefore, yield response and deficit irrigation scheduling are sensitive to soil hydraulic characteristics. The study analyzes this sensitivity depending on factors such as initial soil moisture condition, soil texture, and irrigation scheduling under different levels of limitation in irrigation water. Simulation results indicate that under most scenarios, the impact of initial soil moisture conditions on yield was much more significant than that of soil hydraulic characteristics. However, the impact can also vary depending on the selected irrigation strategy and water limitations. Therefore, for optimal full and deficit irrigation in a crop rotation system, the intra-annual irrigation water allocation should consider the soil water flow between two cropping seasons. In addition, an optimal irrigation strategy can largely mitigate the adverse effects of unfavorable soil hydraulic characteristics. Furthermore, the optimal irrigation strategy improves crop water productivity and food security at the same time.
Effect of both sea-land thermal difference and low-level circulation on finely location of Bohai coastal fog
Authors: Wu Bingui
Published: February 2023

Based on mesoscale automatic weather stations, NCEP FNL reanalysis data and satellite retrivaled fog from 2015 to 2020, the distinction of the land fog and sea fog over the Bohai coastal zone were analyzed. It shows although Bohai coastal fog often occur, they frequently divided into land fog or sea fog by western coastline. In order to explore the causing of this phenomenon, the Bohai coastal fog were selected as the research object in this work. Four types of fog events were taken into account according the following situations, (1) only land fog, (2) Land fog drifting to over marine areas, (3) only Sea fog, (4) Sea fog drifting to over inlands.According to the statistics of the above four fog types, the characteristics and diurnal variation difference of fog show that, although the sea fog and land fog have the same inter-monthly distribution trend and all the most in winter, the difference was still significant. Land fog was more than sea fog in the autumn and winter, while on the contrary in the spring and summer. The event of sea fog and land fog clearly separated by the western coastline mostly occurs in the spring and winter night and lasted less than 12 h.In order to further understand the reason that the coastal fog do or not cross the coastline, Firstly, we compared the two land fog events. One land fog occurred while not crossing the coastline, the other spread to the sea. The results show that, under the condition of a weaker weather systematic low-level circulation, the sea-land breeze thermal circulation humidify the inland air, which is favorable to land fog formation. The eastward inland fog moving into the marine area and dissipate due to the higher sea temperature. The stronger offshore wind is favorable for land fog drifting to the sea, and the fog over the sea can develop with the lower sea temperature. The sensitivity simulation experiment using WRF further made sure, when the SST increased by 5%, as the sea-land breeze strengthened, the fog area that is slightly offshore in the control experiment would retreat to the west of the coastline, and the land fog also showed more dense; while when the SST decreased by 5%, the sea-land wind is suppressed, resulting in the fog cases that originally stopped at the west coastline will spread and cover the Bohai area and maintain for a long time.Secondly, by comparing the two marine fog events, which did or not diffuse westerly across the coastline, the results explore that, under the condition of obvious weather systematic low-level circulation, sea wind is favorable for sea fog diffusing to inland. Without systematic low-level circulation transportation, intensity of thermal differences between sea and land and suitable land temperature will determine whether sea fog can cross the western coastline. In conclusion, the thermal differences and its intensity between sea and land jointly to the favorable systematic low-level atmospheric circulation determine the finely location of fog in the coastal zone area.