bluuebunny/crossref_metadata_2025 huggingface dataset:
Limited intersolubility of Ca and Mg between bridgmanite and CaSiO3-perovskite in the lower mantle
Authors: Wang Lin , Miyajima Nobuyoshi , Wang Fei , Wang Xiaoyu , Katsura Tomoo
Published: February 2023

Bridgmanite and CaSiO3-perovskite, respectively, are the first and third most abundant minerals in the Earth's lower mantle. The intersolubility of Ca and Mg between these two minerals is still under debate. Some studies indicated limited intersolubility, while others suggested a complete dissolution of CaSiO3-perovskite into bridgmanite at lower mantle conditions. This controversy leads to different explanations of the physical properties of the lower mantle such as density, elasticity, and viscosity, accordingly modifying our understanding of the nature and dynamics of the Earth’s interior. Therefore, it is essential to determine the intersolubility of bridgmanite and CaSiO3-perovskite.The intersolubility of Ca and Mg between bridgmanite and CaSiO3-perovskite can be affected by the temperature, pressure, and bulk compositions of the system. Previous studies showed an increase in intersolubility with temperature, but reported no robust pressure and composition dependence. Because FeAlO3 is the second dominant component in bridgmanite, investigating the effect of FeAlO3 content and pressure dependence is essential to clarify the phase relation of the Earth’s lower mantle.This study determined the pressure and FeAlO3 dependence on the intersolubility of bridgmanite and CaSiO3-perovskite at pressures of 27 to 40 GPa at a constant temperature of 2300 K using a multi-anvil press. Two compositions of MgSiO3:CaSiO3 = 1:1 and MgSiO3:FeAlO3:CaSiO3 = 3:2:5 were examined. SEM images clearly show the existence of two phases in all products. TEM-EDS analyses indicate a decrease in the CaSiO3 content of bridgmanite in both systems with increasing pressure. The FeAlO3 component only slightly enhances the CaSiO3 content of bridgmanite: adding the FeAlO3 component increases the CaSiO3 content of bridgmanite from 0.04(2) to 0.3(2) mol.% at 40 GPa. The MgSiO3 content of CaSiO3-perovskite decreases with increasing pressure from 1.8(7) to 0.06(8) mol.% in the FeAlO3-free system, and from 1.2(5) mol.% mol to an unmeasurably small value in the FeAlO3-bearing system. We conclude that, even with the presence of a FeAlO3 component in bridgmanite, the intersolubility is limited and remains nearly constant at different pressures. Thus, bridgmanite and CaSiO3-perovskite should coexist in the lower mantle, and CaSiO3-perovskite is the host mineral of large lithophile elements such as Ca in the lower mantle.
Links Between Volcanic Eruptions and Magma Body Geometry Revealed by Seismic Reflection Imaging at the East Pacific Rise
Authors: Marjanovic Milena , Carbotte Suzanne , Stopin Alexandre , Singh Satish , Plessix René-Édouard , Marjanović Miloš , Nedimović Mladen , Canales Juan Pablo , Carton Hélène , Mutter John , Escartín Javier
Published: February 2023

The structure of the magmatic system beneath subaerial volcanos, including the architecture and distribution of the bodies where magma is stored and the network of conduits that transport melt between these accumulations and the surface, plays a fundamental role in all aspects of volcano construction and evolution, from igneous differentiation to hazard assessment. However, due to inaccessibility, little is known about the geometry of the magma bodies residing beneath subaerial volcanos. Mid-ocean ridges host the most extensive magmatic system on Earth, with 98% of its length below the ocean surface, which makes them an ideal target to be scanned by controlled-source marine seismic techniques. Beneath some portions of this vast system, the shallowest magma bodies are present and represented by long-linear Axial Magma Lenses (AML). It is at these shallow-most AMLs where dikes nucleate and connect the magma accumulations to the surface to result in an eruption. To explore the magma plumbing systems at mid-ocean ridges, we use 3-D multichannel seismic data across a mid-ocean ridge environment and apply advanced marine seismic techniques to develop the highest resolution reflection images of the AMLs so far. The data were collected across a magmatically dynamic portion of the East Pacific Rise at 9°50’N with documented dike intrusion and eruptions in 1991/1992 and 2005/06.The observations indicate that the magma reservoirs in the shallow crust are not represented by smooth bodies, but show strongly lineated topography that is spatially linked to the distribution of eruptive fissures and erupted lavas above. In the detailed topography, we find evidence for: 1) a dike root zone beneath where a caldera-like axial eruptive fissure zone is present, 2) deep excavation of this root zone within the primary eruption site for the last documented eruption, and 3) dikes rupturing from edges as well as the center of magma lenses. We also demonstrate that the distribution of additional, off-axis crustal magma accumulations further impact the stresses and melt budget at shallow-level magma accumulations leading to more frequent eruptions. Our results show that the mechanism behind eruptions along mid-ocean ridges is predominantly bottom-up and not fundamentally different from the eruptions’ mechanism at subaerial volcanoes. Considering the fine-scale morphology of shallow magma bodies will be critical for future generations of more realistic numerical models to aid in effective global volcanic hazard assessment and mitigation.
Structural and thermal evolution of an Archean fold/thrust nappe belt based on quantitative structural profile
Authors: Zhong Yating , Kusky Timothy , Wang Lu , Stüwe Kurt
Published: February 2023

     We report studies of an ancient, ~10 km wide fold/thrust nappe belt developed as one zone of a 150 km wide, Archean collisional orogen in the North China Craton. Principles of cross-section construction and balancing were utilized to derive the first-reported, detailed map and crustal-scale profile of the Archean fold/thrust nappe belt. Combined with stratigraphy and geometric restoration, we demonstrate that the fold/thrust nappe pile consists of four major 2.69-2.52 Ga sub-horizontal nappes stacked upon each other, and ductile shear zones below each of them, emplaced onto a 2.56-2.51 Ga passive margin-like shallow marine platformal para-autochthon at 2.51-2.50 Ga. Four individual nappes were derived from different tectonic belts of an ancient paleo-ocean before they were emplaced. They are characterized by distinctive kinematic and thermal evolution.    Geometric, statistical analysis of structural-fabrics and kinematic indicators illustrate that the fold/thrust nappes of forearc and oceanic floor sequences have been reworked by folding and thrusting with stratigraphic repetition during three kinematic phases, and the final emplacement was accomplished by a combination of rigid body translation along shear zones between nappes and the para-authochthon as well as internal strain by ductile deformation. The para-autochthon only records the predominant D2 event, related to the fold/thrust nappes emplacement, but lacks the records of oldest kinematic phase.    Thermal characteristic inferred by metamorphic studies reveal an inverted thermal structure in the fold/thrust nappes, indicated by the observation of a decrease in metamorphic grade from amphibolite facies in the nappes to greenschist facies in the underlying schistes lustrés forming the basal décollement; but it shows a downward temperature-increase in the metamorphic field gradient in the passive margin para-authochthon with relatively stable pressure records.    This work explicitly unravels the first-order geometry and the tectono-structural evolution of the 2.5 Ga fold/thrust nappe belt by constraints on the scale, structural sequence, and metamorphic grade of the different tectonic units. This provides a quantitative basis for drawing analogies between Archean and present lithospheric deformation and discussing the style of tectonism during Archean orogenesis.
Estuarine filter for trace metals and emerging contaminants: an example from Southampton Water, UK
Authors: Appelt Jana-Sophie , Cundy Andrew , Whiteside Jessica , Bray Paul
Published: February 2023

Organic and inorganic contaminants have deleterious effects on organisms and ecosystems worldwide. Elevated trace metal concentrations are known to cause poisoning and diseases such as Minamata disease, persistent PAHs are found regularly both in industrial discharges and in human body fluids and trace amounts of exogenous hormones can have significant (population level) impacts on aquatic organisms and cause serious diseases, obesity, and infertility in humans. Through wastewater treatment plants, discharge and agriculture, these contaminants end up in aquatic systems and their associated bed sediments. For a range of contaminants, estuarine sediments have been shown to be effective “traps”, moderating contaminant input from rivers to coastal and marine ecosystems, depending on the physical and chemical properties of the sediments. Sediment composition, particle size, organic matter content as well as contaminant chemical structure and speciation play an important role in the interaction between contaminants and sediments. However, for many pollutants, such as hormones, the circumstances that influence these trapping processes are still unclear. Further research is needed to fully understand the behavior of these contaminants and to assess possibilities to reduce their input into the environment and into aquatic food systems.Here, we examine the sedimentary trapping of a range of emerging and conventional contaminants in the intertidal sediments of Southampton Water, a major industrialized and urbanized estuarine system in the southern UK.Sediment cores (dated with Pb-210 and Cs-137 dating) show historical trends in contamination related to waste discharges into the estuary (e.g., for Cu and Pb), while surface sediments indicate point source inputs of contaminants, resulting in sedimentary concentration of contaminants which significantly exceed local geological background concentrations (e.g., Hg, with concentrations up to 2.4 ppm). TOC, δ13C values and major elements indicate an association with the sediment grain size. Ongoing work is examining distribution, trapping and breakdown of hormones and PAHs in sediments, and the role of sediment composition in these processes, using a sample preparation method for the simultaneous analysis of PAHs and hormones in sediments via GC-MSMS. 
Downscaling Hydrodynamic Outputs using Deep Learning for Operational Flood Inundation Forecasting
Authors: Yang Chanyu , O'Loughlin Fiachra
Published: February 2023

Floods can have significant impacts on communities, properties, and critical infrastructure. To reduce these impacts, it is necessary to either protect them via the construction of flood defenses or through developing flood forecasting systems. Previous studies have shown the potential of applying hydrodynamic models for fine spatial resolution inundation modeling; however, such models are computationally demanding (depending on spatial resolution) and are therefore not suitable to meet the need for operational flood forecasting. This study looks at ways to reduce the computational cost of flood inundation forecasting through a combination of hydrodynamic models and machine learning approaches. We propose a deep learning (DL) based approach to downscale coarse resolution hydrodynamic outputs for use in operational flood inundation forecasting. This method was applied to outputs from the LISFLOOD-FP model for a reach of the river Dodder in Dublin City, Ireland, where a 2 m LiDAR DTM and hourly discharge and water levels were available. Three different DL methods were tested: Convolutional Neural Networks (CNNs), Recurrent Neural Networks (RNNs), and Generative Adversarial Networks (GANs). Initial results indicate that GANs outperformed the other two algorithms.
Flood protection in a changing society: a perspective from historical agriculture transformation during 1931 and 1954 floods in Yangtze River Basin, China
Authors: Liu Chang , Kawasaki Akiyuki , Shiroyama Tomoko
Published: February 2023

As the longest river in Asia, the Yangtze River has shown its impact on human societies with floods recorded since 12th century. In 1931, the Yangtze River has manifested its force again with one of the deadliest floods ever recorded in Chinese history, causing 422,499 deaths, damages to more than 25.2 million people and 58.7 billion m2 farmland. Similar flood occurred again in 1954, resulting in 31,762 deaths, damages to 18.9 million people and 31.7 billion m2 farmland. Researches have shown that 1954 flood being larger and higher compared to 1931 flood. However, it is still unclear for what reason that a more severe flood leading to less damage. Was it because of the change of policy and what can we learn from it? To answer this question, first, we constructed a conceptual framework of 1930s and 1950s agricultural society. Then, the flood inundation process of 1931 and 1954 floods was reconstructed with gauged rainfall dataset. After referring to the investigation report, the inundation information was applied to re-estimate the flood damage on farmland, houses, and residents under different scenarios. Furthermore, apart from traditional countermeasures, the effect of society transformation with floods were estimated using the potential crop production (PCP). Finally, an agent-based model (Farmer Landlord Inundation Production, FLIP) was constructed to simulate the agricultural transformation and its impact on residents’ response. The results have shown that traditional countermeasures were of certain effect. For example, the reinforcement of levees in 1950s was more effective in reducing inundation area of 8% compared to 1931, while the construction of detention basins accounted for 2%. However, with only traditional countermeasures failed to explain the relative success of agricultural product in 1954. Which, according to PCP result, the observed rice production was 12% higher than potential in 1954, while it was 29% lower in 1931. Here we assumed such difference could be ascribed to drastic society transformation in 1930s and 1950s (e.g., increase of absentee landlords in 1930s, land reform movement in 1950s). The effect of which was partially demonstrated with FLIP model, indicating an increase of crop production after eliminating landlords during floods. Our results demonstrate how society transformation are likely to affect the damage of and response to floods in a different (sometimes more important) way from traditional countermeasures in modern Chinese history. We anticipate our research to be a starting point towards deeper understanding of human and hazard, and the knowledge of which is likely to be applicable to many other regions and times.
Coupling ice-ocean interface models with global-scale ice shell evolution models applied to Jovian moon Europa
Authors: Rückriemen-Bez Tina , Terschanski Benjamin , Plesa Ana-Catalina , Kowalski Julia
Published: February 2023

The astrobiological potential of the Jovian moon Europa has long been acknowledged [1]. Europa’s surface, icy shell, likely salty ocean, and silicate mantle play a key role in determining Europa’s habitability. In particular, the icy shell may harbor cracks and pockets filled with brine that could be niches for sustaining life.One major question is how and to which degree brines are incorporated into the ice shell and how they evolve. Global models of the ice shell resolving spatial scales of several hundred meters to kilometers are able to constrain the long term evolution of solid salt intrusions [e.g. 2] and potentially brines. Two-phase extensions in global models, however, have so far only been applied to pure water ice shells [3]. Since global ice shell models cannot capture the intake of brine at the ice-ocean interface due to the large scales they act on, they rely on boundary conditions that incorporate the physics of the interface.Meso-scale models of the ice-ocean interface [4, 5] operate on length scales of centimeters to meters. The transition between ice and seawater is treated as a mush containing a mix of solid and high-salinity brine, typically assumed to be in thermodynamic equilibrium [6]. Modern mushy-layer models [7] provide insight into the distribution of salt impurities [8].We review inter-solver coupling strategies and discuss applicability to the coupling of the meso-scale ice-ocean interface and the planetary-scale convection. We propose a spatial homogenization of meso-scale simulation outputs and a Gauss-Seidel subcycling approach [9] to embed the fast into long-term variations. This work will lay the foundation for physically consistent scale-coupled evolution models of the cryohydrosphere of icy moons.[1] K. P. Hand et al., Europa, 2009.[2] L. Han and A. P. Showman, Geophysical research letters, 2005.[3] K. Kalousová et al., Icarus, 2018.[4] J. J. Buffo et al., Journal of Geophysical Research: Planets, 2020.[5] J. J. Buffo et al., Journal of Geophysical Research: Planets, 2021.[6] D. L. Feltham et al., Geophysical Research Letters, 2006.[7] J. R. G. Parkinson et al., Journal of Computational Physics, 2020.[8] J. J. Buffo et al., Journal of Geophysical Research: Planets, 2021.[9] 3 - The coupling methods. In: Multiphysics Modeling, Academic Press, Oxford, 2016.
Comparison of seismic phase association algorithms and their performance.
Authors: Puente Huerta Jorge Antonio , Sippl Christian
Published: February 2023

Seismic phase association is a fundamental task for earthquake detection and location workflows, as it gathers individual seismic phases detected on multiple seismic stations and associates them to events.Current phase picking algorithms are capable of generating large phase datasets, and together with new improved phase association algorithms, they can create larger and more complete earthquake catalogs when applied to dense seismic networks (permanent or temporary).As part of project MILESTONE, which aims at the automatic creation of large microseismicity catalogs in subduction settings, the present study evaluates the performance of three different phase association algorithms, both by comparing their outputs with a handpicked benchmark dataset and by the retrieval of synthetic events.For this purpose, we used seismic data from the IPOC (Integrated Plate boundary Observatory Chile) permanent deployment of broadband stations in Northern Chile.We manually picked P and S phases of raw waveforms on randomly chosen days, with event rates in excess of 100-150 per day. All events that were visually recognizable were picked and located, leading to a dataset to be used as “ground truth”.We do the phase picking with EQTransformer (Mousavi et al. 2020) and evaluate the performance of three seismic phase associators: 1) PhaseLink (Ross et al. 2019), a deep learning based approach trained on millions of synthetic sequences of P and S arrival times, 2) REAL (Zhang et al. 2020), that combines the advantages of pick-based and waveform-based methods, primarily through counting the number of P and S picks and secondarily from travel-time residuals, and 3) GaMMA (Zhu et al. 2021), an associator that treats the association problem as an unsupervised clustering problem in a probabilistic framework.In the synthetic test we use NonLinLoc raytracer and add random noise, as well as false picks to simulate an automatic picker output.In both experiments we evaluate the number of correctly associated and lost events, and the number of constituent picks per event.
Evaluation and Modification of Microphysics Schemes on the Cold Pool Evolution for a Simulated Bow Echo in Southeast China
Authors: Zhao Kun , Zhou Ang , Lee Wen-Chau , Huang Hao
Published: February 2023

The microphysical processes were found to be vital in facilitating the system evolution for a merger-formation bow echo (MFBE) in southeast China, where the reinforced precipitation enhanced the cold pool strength via evaporation cooling. However, current numerical model failed to accurately perform such processes, suggesting the large uncertainties for microphysical schemes in simulating MFBE events in southeast China. In this study, three microphysics schemes including Thompson (THOM), Morrison (MORR), and Weather Research and Forecasting Double-Moment 6-Class (WDM6) schemes were evaluated by comparing against polarimetric observations and Variational Doppler Radar Analysis System (VDRAS) analyses. The three schemes captured the basic kinematic structures for this MFBE event after assimilating radar radial velocities, but all underpredicted the cold pool strength by ∼25%. Particularly, THOM produced the best raindrop size distributions (DSDs) and precipitation pattern, and the larger raindrop size bias and the weak cold pool strength were owing to the relatively low rain breakup efficiency and inefficient rain evaporation, respectively. By decreasing the cutoff diameter of rain breakup parameterization from the default 1.6–1.2 mm (i.e., increasing breakup efficiency) and increasing evaporation efficiency by threefold in THOM, the simulated DSDs and precipitation were greatly improved, and the cold pool strength was significantly increased from 77% to 99% compared to that in VDRAS analyses. This study illustrated a plausible approach of combining polarimetric radar retrievals and VDRAS analyses as bases to adjust THOM default settings in simulating a MFBE event in southeast China with physical characteristics more consistent with observations. Since microphysical processes vary from convective organizations and climate regions, it is recognized more cases studies are needed in the future to examine the validity and approach in this study to improve simulations and predictions of MFBEs in southeast China.
Mapping and inventorying rock glaciers on the Tibetan Plateau from Planet Basemaps using deep learning
Authors: Sun Zhangyu , Hu Yan , Liu Lin , Racoviteanu Adina , Harrison Stephan
Published: February 2023

Rock glaciers are geomorphologically valuable indicators of permafrost distribution and form potentially important hydrological resources in the context of future climate change. Despite the widespread distribution of permafrost on the Tibetan Plateau and its reputation as the "water tower of Asia", this region lacks a complete inventory and systematic investigation of rock glaciers. In this study, we develop a deep-learning-based approach for mapping rock glaciers on the Tibetan Plateau. A powerful deep learning network, DeepLabv3+, is trained using Planet Basemaps as training imagery and multi-source rock glacier inventories as training labels. The well-trained model is then used to map new rock glaciers. The visually consistent and cloud-free properties of Planet Basemaps are crucial for developing comprehensive maps of rock glacier distribution; and the rock glacier inventories from multiple regions can improve the volume and diversity of the training dataset. The deep learning mapped results present strong identification and acceptable boundary delineation of rock glaciers, indicating that the deep learning model could serve as a useful tool for facilitating the inventory of rock glaciers over vast regions. Based on the deep learning outputs, we compile 4233 rock glaciers on eight subregions of the Tibetan Plateau, which are widespread in the surrounding regions while being scarcely distributed in inner areas. Talus- and glacier-connected rock glaciers are two major classes, which are dominant on the southeastern and densely distributed on the northwestern Tibetan Plateau, respectively. The regions with steep slopes are favored by rock glacier clusters with high density, and glacier-abundant regions tend to breed large rock glaciers. The proposed rock glacier mapping method effectively speeds up inventorying efforts, which will be used to map and inventory rock glaciers on the entire Tibetan Plateau. The complete inventory will offer a significant contribution to the global catalog and serves as a benchmark dataset for modeling and monitoring the state of permafrost in a changing climate. 
Comparative analysis of analytical and numerical solutions for hydraulic properties upscaling in fractured media
Authors: De Paolo Erica , Bistacchi Andrea , Casiraghi Stefano , La Valle Fabio
Published: February 2023

The investigation of hydro-mechanical properties in rock formations is of utmost importance for several geological and engineering applications, e.g. for carbon-dioxide or hydrogen underground storage, exploitation of groundwater, geothermal or oil and gas reservoirs, hydrothermal ore deposits, and the mechanics of earthquakes. In particular, modeling fluid flow into networks of discontinuities (i.e. faults and fractures) is a key task in all these studies. Due to the high complexity of such processes, involving a significant number of feedbacks and occurring at different spatial and time scales, the achievement of a satisfying representation of the physical problem remains a challenge.In the last decades, a variety of modeling approaches have been proposed in literature, accounting for different orders of complexity and using several computational methods. Analytical solutions are commonly based on simplistic assumptions about the process, allowing for simple fracture geometries and/or implying incompressible Newtonian fluids; as well as about the medium, considered elastic and permeable (or impermeable). Nevertheless, these solutions are still widely employed, as they provide significantly quick, first-order solutions compared to more sophisticated approaches.On the other hand numerical models, typically accounting for a higher number of parameters and concurrent effects, are expected to return more realistic solutions. Those based on Finite Element Methods (FEMs) or similarly discretized domains, for example, permit to model the fractured rock mass with information that can be inferred from geological surveys and geophysical techniques.As anticipated, important limitations in the use of more advanced modeling approaches could be the computing time and model size or resolution, not always allowing for cost-efficient solutions. In this study, we aim at a comprehensive review and benchmarking of the main classes of existing methods, comparing their results obtained for an identical dataset. In this way, we are able to highlight the advantages and disadvantages of each technique, defining the differences in accuracy and the ranges of applicability of these methods. The outcomes of our work are intended as a cross-benchmarking among available models, as well as a starting point for the future development of novel improved techniques in the field of fluid flows dynamics in networks of discontinuities.
Methane cycling at buried abandoned wells in a peat-rich area in northern Germany – curse or blessing for atmospheric emissions and emission studies?
Authors: Jordan Sebastian , Schlömer Stefan , Krüger Martin , Blumenberg Martin
Published: February 2023

In the worldwide effort to reach the 1.5-degree target, governments try to mitigate anthropogenic methane emissions. One example is the oil & gas sector, which is responsible for the second most anthropogenic methane emission source after agriculture. Abandoned oil and gas wells are seen as a promising target, as they can in some cases emit up to several tons of methane per year. However, only the USA includes emissions from such wells into their yearly greenhouse gas emission inventory and only for a few other countries like Canada, the United Kingdom, Romania and the Netherlands measured data on methane emissions from abandoned gas wells are available. Most countries do not even have sufficient data regarding numbers, positions, and status of their abandoned wells let alone the related methane emissions. Germany has about 20,000 abandoned wells, which are generally filled and buried, however, it is unclear, whether they are emitting methane or not.Here, we present our approach and first data to fill this knowledge gap for Germany regarding methane emissions from onshore-abandoned oil and gas wells. For our first measuring campaign we focused on five regions in Lower Saxony (Federal State in Northern Germany) measuring 29 wells, covering both backfilled exploration and abandoned production wells of oil and gas fields. We will present our preliminary results including rates of soil methanotrophy focusing on one region with both, shallow oil wells and industrial peat production. Our data demonstrate the necessity for detailed knowledge on background methane emissions and cycling particularly in such methane-laden settings.
Ambient noise variation in the South Pole
Authors: Pradhan Gyanasmita , Reddy Ramakrushna , Singha Roy Paresh Nath
Published: February 2023

Ambient noises are generated due to the interaction of atmosphere with the solid Earth and the noises which occur within the time period of 2-20s are known as microseisms. As the noise generation mechanism is not very well understood in the extreme climatic condition of Antarctic continent, in this study we target to understand the microseism generation in the South Pole station situated in the Antarctic continent. We have carried out our analysis using continuous data from IRIS data management center. Our main focus is to characterize the source direction of noise and their seasonal amplitude variations. We have employed the frequency dependent polarization analysis through the Eigen decomposition of the 3×3 spectral covariance matrix. The source of the noise have been analyzed using the backazimuth and time period for all the three bands of microseism, SPDF (short period double frequency), LPDF (long period double frequency), and PM (primary microseism). We observed that the noise is mainly due to the strong winds of Southern Ocean and some amounts of noise are also from the Ross Sea. In southern hemisphere, winter starts from May and it ends in August and also the number of polarized signals is lower in the winter season, and it is comparatively higher in the summer season. Additionally, when we plot Power spectral density against time period we see the splitting of the double frequency microseism into SPDF and LPDF which is only observed in the summer months and not in the winter months (only one single peak is observed).  Because, in the winter month’s sea ice concentration is extremely high in the South Pole; therefore, there is no significant wind interaction with sea waves of the coastal part which generates the SPDF. In winter, the continent is completely frozen; however, the amplitude of noise is high due to the strong winds. In summer, the noise is generated due to the low pressure systems develops in Southern Ocean which leads to cyclones in the Ross Sea. Antarctic circumpolar current also plays a significant role in the generation of noise. Therefore, we can conclude that the source of noise is from the Southern Ocean and Ross Sea. Also, we noticed the seasonal variation in the splitting of the double frequency microseism due to variation in the sea ice concentration.
Evaluating the impact of infiltration from sealed surfaces and green infrastructure on urban pluvial flooding
Authors: Dobkowitz Sophia , Seleem Omar
Published: February 2023

Urbanization and climate change are increasing the frequency and severity of urban pluvial flooding. The traditional urban modelling approaches do not take infiltration from sealed surfaces into account, leading to an overestimation of excess runoff. Still, the conventional centralized sewage systems are often overburdened. While municipalities are taking initiatives to utilize green infrastructure as a sustainable way to manage stormwater, the performance of the implemented measures varies from region to region. This study uses the WaSim-ETH physically based hydrological model to investigate runoff and infiltration processes in urban areas and determine how much rainfall contributes to runoff and infiltrates through different types of land use surfaces. It also evaluates the efficiency of green infrastructure to reduce the generated runoff from different rainfall events. The model is applied to study areas in Berlin and Würzburg, both cities have experienced frequent pluvial flooding in the last decades.
A multi-order joint inversion for potential field modelling.
Authors: Bianco Luigi , Tavakoli Mojtaba , Vitale Andrea , Fedi Maurizio
Published: February 2023

We propose a joint inversion method for potential fields aiming at recovering reliable models of complex source distributions, as those involving either shallow or deep-seated bodies. In this case, anomalies are characterized by different wavelength-contents, so that we may try to invert jointly the field and its higher-order vertical derivatives. To accomplish this task, we adopt a sequential strategy with a cross-gradient constraint. In this way, we can decouple the combined objective function into three terms: the field, its vertical-derivative and the cross-gradient constraint. For either separate or joint inversion we used a modified focusing algorithm, able to produce compact—source models and to incorporate different types of a-priori information (softer or harder constraints) to better address the ambiguity. The softer constraints include the model weighting function. Specifically, we used the inhomogeneous form of the model weighting function. On the other hand, we introduced harder constraints in the form of a reference model, which allows introducing other information from geology, previous geophysical interpretations or from well logs. The strength of the method is the applicability on both gravity and magnetic field to investigate different scenarios from small-scale (cavity detection) to basin-scale (resources exploration). In all the proposed cases, we obtained a significant model of the different sources at any depths. This is further demonstrated by a strong decrease in the cross-gradient values and a meaningful clusterization in the cross-plot of physical parameters.
Clustering of flood-aggravating pathways in the forelands of Pre-Alpine Region
Authors: Koc Gamze
Published: February 2023

Upper Bavaria has comparatively higher mean rainfall amounts than other regions in Germany when the long-term rainfall data analyzed. Those heavy rainfall events cause severe human and economic impacts in the region. However, when the precipitation patterns (i.e. intensity, duration, etc.) were examined for this region, it is possible to see that similar rainfall patterns might cause different impacts in different districts of Oberland. This situation underlines the importance of understanding the different aggravating pathways of heavy rainfall events in the region. For this aim, flood-aggravating pathways such as topographic features, land use types, soil moisture and infiltration properties of the events in Oberland between the years 2001-2021 were analyzed. To determine the dominant influencing mechanisms, aggravating pathway factors are classified using hierarchical clustering for the study area. The classification results are compared with the heavy rainfall events defined by the German Weather Service (DWD), Catalogue of Radar-based Heavy Rainfall Events (CatRaRE catalogue) in terms of precipitation duration and amount, as well as fire brigade operations in the area regarding the impacts.Herewith, direct or indirect relevance of rainfall patterns and catchment properties on the flood events in Oberland (Upper Bavaria), Germany between the years 2001 and 2021 are investigated with this study. The outcomes could provide beneficial information on different aggravating mechanisms in different districts in Oberland and could be used for future land-use planning and flood risk prevention studies.
Isotopic fractionation of sulfur during COS hydrolysis
Authors: Avidani Yasmin , Davidson Chen , Angert Alon , Amrani Alon
Published: February 2023

Carbonyl Sulfide (COS) is the most abundant sulfur-containing gas in the atmosphere, and it is used as a proxy for terrestrial gross primary productivity (GPP). There are uncertainties in the COS fluxes estimations that limit this approach. Oceans are the major source of COS to the atmosphere. In the oceans, the COS is produced by photochemical reactions and "dark production", whose mechanism is not well understood. Hydrolysis is the major process that removes COS from the ocean's surface. Identifying the sulfur isotope values (δ34S) and the isotopic fractionation (e) associated with these major sources and sinks could decrease the uncertainties in the fluxes, based on an improved COS global model with an isotopic mass balance [1]. In the current study, we aim to determine the e  during the hydrolysis process of COS (eh).  We use a purge and trap system coupled to a GC/MC-ICPMS to measure δ34S values during hydrolysis under different pH, salinity (S), and temperature, representing various oceanic conditions. We calculate from our δ34S and COS concentration measurements a eh of −2.6 ± 0.3‰ in natural seawater from the Gulf of Aqaba (pH 8.2, 22 , S=41‰). Using an artificial solution at similar pH and temperature conditions (pH 8.0, 22 , S=0.2‰) we found eh of −2.3 ± 0.2‰, hence, salinity has no significant effect on the fractionation. Using the same artificial solution at 4   we found eh  of −3.9 ± 0.2‰, thus fractionation increases with decreasing temperatures, as can be expected from theory. We will also report the effect of acidity on eh from experiments in pH of 4 and 9 (at 22 ). This information on the eh will help us to understand the contribution of COS hydrolysis to the oceanic source and in the future to establish an isotope mass balance model to decrease the uncertainty of this major source.[1] Davidson, Chen, Alon Amrani, and Alon Angert. "Tropospheric carbonyl sulfide mass balance based on direct measurements of sulfur isotopes." Proceedings of the National Academy of Sciences 118.6 (2021): e2020060118. 
IMPROVER: Performance in the July 2022 UK Heatwave
Authors: Ayliffe Ben , Evans Gavin , Moseley Stephen
Published: February 2023

The UK Met Office is developing an open-source probability-based post-processing system called IMPROVER (Integrated Model Post-Processing and Verification) to exploit convection permitting, hourly cycling ensemble forecasts. The system blends these forecasts with both deterministic nowcast data, and coarser resolution global ensemble model data, to produce seamless gridded and site-specific probabilistic forecasts, from the very short to medium range.

In July 2022, the UK experienced its hottest ever recorded temperatures, with 40°C exceeded in numerous locations. Over this period the UK Met Office was running the IMPROVER ensemble post-processing system in parallel with its legacy post-processing system. This provided an opportunity to compare the guidance the two systems gave in the run-up to this extreme event, and to reflect afterwards on the positives and negatives of each system. This comparison was particularly timely, coming in the months preceding IMPROVER’s adoption as the data source for operational products from spring 2023.

In this talk we will present the results of these post-processing system comparisons. We will highlight the role post-processing played in giving good forecast guidance for these record-breaking temperatures and discuss some issues that arose within our configuration of IMPROVER when conditions reached unexpected extremes.
Future changes in North Atlantic winter cyclones in CESM-LE simulations from a Lagrangian-composite perspective
Authors: Dolores-Tesillos Edgar , Pfahl Stephan
Published: February 2023

Extratropical cyclone airstreams, such as warm conveyor belts (WCBs), are linked to strong precipitation along with latent heat release at low levels and, thus, changes in the low-level PV distribution. Previous studies have shown significant changes in PV anomalies in a future climate under the RCP8.5 scenario, which are also associated with changes in strong near-surface winds. However, the source of these PV anomalies is still unclear, especially at upper levels. Based on the 1% strongest winter-cyclones in the North Atlantic (NA) region over the two periods 1990-2000 and 2091-2100, we adopt a Lagrangian perspective to investigate such changes in CESM Large Ensemble simulations.Backward trajectories are computed to explicitly identify the contributions of diabatic processes to future changes in cyclone-associated PV anomalies. Moreover, the role of specific airstreams in PV generation/destruction is examined with Lagrangian composites.The results show a sinificant change in the mean trajectory properties 24 hours before the maximum cyclone intensity at low and upper levels. This period of 24 hours is taken to construct Lagrangian composites at 700 hPa and 250 hPa, which provide insights into changes in WCB and dry intrusion (DI) airstreams. We further analyze these airstrem changes by constructing cross sections downstream (WCB regime) and at the equatorward side (DI regime) of the cyclone center.In general, increased diabatic heating along backward trajectories amplifies positive PV anomalies near the cyclone center at both lower and upper levels in a warmer future climate. More specifically, a poleward and upward shift of the WCBs with a larger PV production at middle levels are is found. DIs near the cyclone center are projected to be responsible for stronger PV production at low levels to the south of the cyclone center. At upper levels, the decreased PV anomaly to the south of the cyclone center results from a combined effect of a decreased climatological PV in the NA region and a shift in the origin of the air masses. The increasing importance of diabatic processes in a wamer climate suggests that a better representation of these processes in climate models is necessary to reduce uncertainties.
Representation of Arctic hydrology in a global land surface model
Authors: Stacke Tobias , de Vrese Philipp , Brovkin Victor
Published: February 2023

Earth System Models (ESMs) are the best available tools to project the coupled dynamics of the climate and biogeochemistry under future emission scenarios. However, the future trajectories simulated by individual ESMs vary substantially with most pronounced differences in the high northern latitudes. As recently demonstrated (de Vrese et al., 2022), a significant part of this uncertainty might result from the different approaches and parametrizations of surface and soil hydrology in the permafrost regions. However, this study did not account for sub-grid lateral fluxes.
To make a step forward, we further develop ICON-Land/JSBACH4, the land surface model (LSM) used within the ICON-ESM. Our recent efforts are focused on improving the simulation of Arctic hydrology by accounting for lateral water flows on small spatial scales, i.e. within the grid cells of the LSM. For this, we apply a tiling structure in which we define the spatial relation between parts of the grid cell in terms of water exchange. In this way, the model gets information about the source and sink tiles of surface runoff (based on topography) but also of lateral soil water exchange (based on proximity and soil moisture gradient).This approach results in a redistribution of surface and soil water within the grid cells with drier upland and wetter lowland regions and the correspondent changes in evapotranspiration. Comparing coupled land-atmosphere simulations with different prescribed fractions of upland and lowland areas, we see strong impacts of the tiling structure. Setups with a larger lowland-to-upland ratios lead to higher cloud cover and by up to 2K lower summer surface temperature over larger parts of the boreal regions. This result emphasizes the importance of representing the complex processes of Arctic hydrology, but also the need for detailed information about Arctic land surface properties.
References:
de Vrese, P., Georgievski, G., Gonzalez Rouco, J. F., Notz, D., Stacke, T., Steinert, N. J., Wilkenskjeld, S., and Brovkin, V.: Representation of soil hydrology in permafrost regions may explain large part of inter-model spread in simulated Arctic and subarctic climate, The Cryosphere Discuss., https://doi.org/10.5194/tc-2022-150, in review, 2022.
Convergence of HPC, Big Data and Machine Learning for Earth System workflows
Authors: Elia Donatello , Scardigno Sonia , D'Anca Alessandro , Accarino Gabriele , Ejarque Jorge , Immorlano Francesco , Peano Daniele , Scoccimarro Enrico , Badia Rosa M. , Aloisio Giovanni
Published: February 2023

Typical end-to-end Earth System Modelling (ESM) workflows rely on different steps including data pre-processing, numerical simulation, output post-processing, as well as data analytics and visualization. The approaches currently available for implementing scientific workflows in the climate context do not properly integrate the entire set of components into a single workflow and in a transparent manner. The increasing usage of High Performance Data Analytics (HPDA) and Machine Learning (ML) in climate applications further exacerbate the issues. A more integrated approach would allow to support next-generation ESM and improve the workflow in terms of execution and energy consumption.Moreover, a seamless integration of components for HPDA and ML into the ESM workflow will open the floor to novel applications and support larger scale pre- and post-processing. However, these components typically have different deployment requirements spanning from HPC (for ESM simulation) to Cloud computing (for HPDA and ML). It is paramount to provide scientists with solutions capable of hiding the technical details of the underlying infrastructure and improving workflow portability.In the context of the eFlows4HPC project, we are exploring the use of innovative workflow solutions integrating approaches from HPC, HPDA and ML for supporting end-to-end ESM simulations and post-processing, with a focus on extreme events analysis (e.g., heat waves and tropical cyclones). In particular, the envisioned solution exploits PyCOMPSs for the management of parallel pipelines, task orchestration and synchronization, as well as PyOphidia for climate data analytics and ML frameworks (i.e., TensorFlow) for data-driven event detection models. This contribution presents the approaches being explored in the frame of the project to address the convergence of HPC, Big Data and ML into a single end-to-end ESM workflows.