bluuebunny/crossref_metadata_2025 huggingface dataset:
The early postseismic phase of Tohoku-Oki earthquake (2011) from kinematics solutions: implication for subduction interface dynamics
Authors: Periollat Axel , Radiguet Mathilde , Weiss Jérôme , Twardzik Cédric , Cotte Nathalie , Marill Lou , Socquet Anne
Published: February 2023

Earthquakes are usually followed by a postseismic phase where the stresses induced by the earthquakes are relaxed. It is a combination of different processes among which aseismic slip on the fault zone (called afterslip), viscoelastic deformation of the surrounding material, poroelastic relaxation and aftershocks. However, little work has been done at the transition from the co- to the postseismic phase, and the physical processes involved. We study the 2011 Mw 9.0 Tohoku-Oki earthquake, one of the largest and most instrumented recent earthquakes, using GEONET GPS data. We focus on the few minutes to the first month following the mainshock, a period dominated by afterslip. Based on the method developed by Twardzik et al. (2019), we process 30-s kinematic position time series and we use it to characterize the fast displacements rates that typically occur during the early stages of the postseismic phase. We quantify precisely the co-seismic offset of the mainshock, without including early afterslip, and we also characterize the co-seismic offset of the Mw 7.9 Ibaraki-Oki aftershock, which occurred 30 minutes after the mainshock. We analyze the spatial distribution of the co-seismic offsets for both earthquakes. We also use signal induced by the postseismic phase over different time windows to investigate the spatio-temporal evolution of the postseismic slip. We determine the redistribution of stresses to estimate the regional influence of the mainshock and aftershock on postseismic slip. From a detailed characterization of the first month of postseismic kinematic time series, we find that the best-fitting law is given by an Omori-like decay. The displacement rate is of the type v0/(t+c)p with spatial variation for the initial velocity v0 and for the time constant c. We find a consistent estimate of the p-value close to 0.7 over most of the studied area, apart from a small region close to the aftershock location where higher p values (p~1) are observed. This p value of 0.7 shows that the evolution of the Tohoku-Oki early afterslip is not logarithmic. We discuss about the implications of these observations in terms of subduction interface dynamics and rheology. We also discuss about the different time-scales involved in the relaxation, and how this model, established for the early postseismic phase over one month, performs over longer time scales (by comparison with daily time series lasting several years).Twardzik Cedric, Mathilde Vergnolle, Anthony Sladen and Antonio Avallone (2019), doi.org/10.1038/s41598-019-39038-z Keywords: Early Postseismic, Afterslip, GPS, Kinematic, Omori Law
Impacts of Ocean Tide Loading displacement on Large-scale InSAR Time-series analysis
Authors: Wu Zhou , Jiang Mi , Xiao Ruya
Published: February 2023

With the rapid development of modern Interferometric Synthetic Aperture Radar (InSAR) missions, SAR images with wider geographic coverage can be used to monitor ground deformation from local to continental scale. In such a large-scale application scenario, the ocean tide loading displacement introduces a long-wavelength error, which increases with distance, from millimetre to decimetre-level in InSAR interferograms over coastal areas. Despite great efforts being made to investigate the impacts of OTL on InSAR, these works are limited to individual interferograms and seldomly used in time-series analysis. In this study, we fully explore the OTL effects on Sentinel-1 InSAR time-series data along the western coast of the UK. We adopted wavelet analysis to indicate that the OTL displacement creates periodic signals with major cycles of 15 and 64 days under the 6- and 12-day Sentinel-1 sampling rates, respectively. These periodic signals are responsible for high noise magnitude of time-series displacement up to ~1cm and ~1 cm/yr bias on estimated velocities. An example is shown in Figure 1, where large velocity bias (a1-a3) and time-series standard deviation (b1-b3) can be seen along the western coastline of non-OTL corrected deformation fields, which are considerably eliminated after OTL correction. Our further validation against GNSS observations reveals that OTL correction improves the accuracy of large-scale InSAR time-series analysis by 25%.
Machine Learning Emulation of 3D Shortwave Radiative Transfer for Shallow Cumulus Cloud Fields
Authors: Chiu Jui-Yuan Christine , Yang Chen-Kuang Kevin , Gristey Jake J. , Feingold Graham , Gustafson William I.
Published: February 2023

Clouds play an important role in determining the Earth’s radiation budget. Despite their complex and three-dimensional (3D) structures, their interactions with radiation in models are often simplified to one-dimensional (1D), considering the time required to compute radiative transfer. Such a simplification ignores cloud Inhomogeneity and horizontal photon transport in radiative processes, which may be an acceptable approximation for low-resolution models, but can lead to significant errors and impact cloud evolution predictions in high-resolution simulations. Since model developments and operations are heading toward a higher resolution that is more susceptible to radiation errors, a fast and accurate 3D radiative transfer scheme becomes important and necessary. To address the need, we develop a machine-learning-based 3D radiative transfer emulator to provide surface radiation, shortwave fluxes at all layers, and heating rate profiles. The emulators are trained for highly heterogeneous shallow cumulus under different solar positions. We will discuss the performance of the emulators in accuracy and efficiency and discuss their potential applications.
Electron-astrophysics in the solar wind: plasma physics at F-Class, lessons learned and things to do.
Authors: Wicks Robert , Verscharen Daniel
Published: February 2023

ESA F-Class missions offer a new opportunity to do space science with smaller, cheaper spacecraft. The mission format presents a tough challenge for plasma physics missions, can we make simple, small and cost-effective spacecraft for a topic that will make breakthrough discoveries? This presentation will discuss the past two proposals of the Debye mission, the lessons learned and the challenges ahead to make a similar mission feasible. Debye addresses a grand-challenge problem at the forefront of physics: to understand how energy is transported and transformed in plasmas. The smallest characteristic scales, at which electron dynamics determines the behaviour of energy, are the next frontier in space and astrophysical plasma research. Debye will be the first electron-astrophysics mission. Electron-kinetic processes operate at very small scales (< 10 km) but define the behaviour of the plasma at system-size scales. Debye will use the solar wind as a natural plasma laboratory to measure these electron-scale processes. Understanding the heating, acceleration, thermalisation, and heat flux of electrons is fundamental to our understanding of the dynamics and thermodynamics of plasmas throughout the Universe and thus to the entire field of astrophysics. Debye will answer the fundamental science question "How are electrons heated in astrophysical plasmas?" The mission will make the highest-resolution measurements of electrons ever made in space in terms of energy, angle, time, and space, coupled with two-point high-cadence field measurements to identify the plasma fluctuations responsible for electron energisation. This mission concept will provide ground-breaking and transformative physics results since the combination of rapid particle and field measurements over distances of less than 10 km is completely unprecedented. We believe Debye is a fast, feasible, and focussed mission, tailored to achieve these science objectives, but there are some technical challenges that are assessed to be problematic, how can we address data transmission, formation flying, the cost of multi-item payloads and multi-spacecraft missions?
Weakly nonlinear focused wave group on arbitrary shear based on second-order theory
Authors: Zheng Zibo , Li Yan , Ellingsen Simen
Published: February 2023

Using a recently developed second-order theory of  irregular waves on a current varying arbitrarily with depth [1], we study dispersive focussing of wave groups and their dependence on the current profile.  Long-crested wave groups are presumed to propagate obliquely on a flow with non-linear dependence on depth. We investigate the wave surface elevation and wave kinematics of a focused wave group. Nonlinear wave surface elevations vary with the angle between the wave propagation and flow, and it is found that they increase to a maximum where the current increases adversely for larger depth. For wave kinematics, the horizontal wave-induced velocity shows significantly different behaviours due to the presence of shear current.The development of the highest crest as a function of propagation time is studied for a wave group which linearly focusses at a particular position and time in the absence of shear. The adverse shear causes an increase in maximum height. Exponential and linear depth dependence is compared, and a real, measured shear current [2] is used showing the practical importance of the results.The results complement our recent study of weakly nonlinear wave statistics in the presence of arbitrary vertical shear, which showed among other observations, a strongly increased probability of rogue waves in the presence of an adverse vertical shear, in accordance with field observations by Zippel and Thomson [2]. [1] Zheng, Z, Li, Y and Ellingsen, S Å 2023 “Statistics of weakly nonlinear waves on currents with strong vertical shear” Phys. Rev. Fluids (accepted, in press)[2] Zippel, S and Thomson, J 2017 “Surface wave breaking over sheared currents: Observations from the Mouth of the Columbia River J. Geophys. Res.: Oceans 24 127102.
A multi-thermal analysis of M-class flare observed in common by STIX and XSM
Authors: Kepa Anna , Siarkowski Marek , Awasthi Arun Kumar , Sylwester Barbara , Sylwester Janusz
Published: February 2023

During nearly three years of operation, STIX aboard Solar Orbiter observed thousands of flares.   Many of them were simultaneously observed by Solar X-Ray Monitor (XSM) on board Indian Chandrayaan-2 circling the Moon.  We present results of a multi-wavelength study for  one selected flare  of M GOES class as seen from 1.a.u. STIX data provided  the opportunity for a detailed analysis of hard X-ray emission in several energy bands including the light curves, reconstructed hard X-ray images and spectra. The differential emission measure diagnostics of the flaring plasma have been carried out based on interpretation of the XSM X-ray spectra. Using the differential evolution (DE) approach we have determined the “full” model of emitting source including the temperature, emission measure and elemental abundances as determined simultaneously throughout the flare.  We discuss patterns of elemental composition history for individual plasma temperature components.
Recent kinematics of Crete, observed by InSAR, reveal complex, curved-forearc deformation and aquifers changes
Authors: Metzger Sabrina , Uddin Md Aftab , Mouslopoulou Vasiliki , Begg John , Nicol Andy , Saltogianni Vasso , Oncken Onno
Published: February 2023

Located on the overriding plate of the Hellenic subduction margin, the 250 km-long island of Crete offers a unique opportunity to study curved-forearc deformation. The African-Eurasian plate-convergence of ~40 mm/yr (~80 %) is primarily accommodated aseismically, but intense seismicity is recorded at the plate-interface and a reverse splay faults along the Hellenic trough; frequent M6+ earthquakes and (at least one) tsunami-genic event, causing up to 10 m of paleoshoreline uplift in western Crete, are reported. Global Navigation Satellite System (GNSS) data revealed N-S shortening of ~2 mm/yr within western Crete due to pure plate convergence. Further east, the curved subduction trench accommodates increased oblique slip, causing E-W extension of ~2 mm/yr in eastern Crete.Recently, the European Ground Motion Service published dense InSAR surface deformation data in East and Up direction of whole Europe. The InSAR time-series comprise positioning samples every six days, respectively, every ~50 m, and, in Crete, exhibit long-wavelength deformation signals caused by deep-rooted, tectonic sources that are overlaid by (often seasonally-modulated) signals originating in shallow aquifers. We analyze these time-series in space and time and validate the results using available GNSS rates, a seismic catalog and an active fault data base. Preliminary results suggest a slight eastward tilt of Crete, which is not confirmed by published GNSS rates, and has to be investigated further. Spatially-confined uplift of up to ~5 mm/yr are observed at the karstic Omalos plateau, and up to ~30 mm/yr subsidence in the Messara basin, both probably related to groundwater replenishment/abstraction. Relative eastward motion increases towards eastern Crete, particularly in the fault zones embracing Mirabello bay and east of it, thus confirming the aforementioned E-W extension, and towards the southern coast.
Analysis of precipitation records from climate models in a non-stationary context
Authors: Gonzalez Paula , Naveau Philippe , Thao Soulivanh , Worms Julien
Published: February 2023

In the context of climate change, assessing how likely a particular change or event has been caused by human influence is important for mitigation and adaptation policies. Disturbances, such as increases in the frequency and intensity of extreme precipitation have been observed at continental to global scales. In this work we present an Extreme Event Attribution methodology for yearly maxima records that takes into consideration the temporal non-stationarity of climate variables and allow us to quantify record probability at a global scale in a transient setup. We apply our methodology to study records of yearly maxima of daily precipitation issued from the numerical climate model IPSL-CM6A-LR and the scenario rcp8.5 at a global scale. Focusing on decadal records, we detect a clear anthropogenic signal from the 2020's, even thought decadal record probability increases in most parts of the world, we observe a decrease of records probability in the subtropics.
The effectiveness of using virtual reality materials in preparing students for geological fieldwork
Authors: van Bever Donker Jan , Marshal Delia , Huber Matthew , Maart Rudy , Mayekiso Luyanda , Solomon Henok , Mgabisa Nompumelelo
Published: February 2023

BackgroundDuring the recent worldwide lockdowns due to the COVID-19 pandemic, several institutions around the world, out of necessity replaced their customary field work with virtual field trips, using existing photographic materials gathered over many years conducting the same fieldtrip, causing the lecturers to conclude that this was a reasonable alternative as the marks scored were similar. Several years before the pandemic hit, UWC’s Applied Geology section had already embarked on the development of high-resolution virtual field tours (VFTs)to use as supplementary material in the provision of field education to our geology students, based on the geocognition concept.  This was done as rising costs and increasing health and safety rules effectively forced us to keep fieldwork for students to an absolute minimum, which is unacceptable in geology education. Additionally, in this manner, students could be exposed to classical geology sites from anywhere in the world without having to travel there, as an archive of prime teaching outcrops could be built like this.MethodologyWe created the Virtual Field Tours using High Resolution Photography and constructed the tours using Pano2VR enhanced with videos and drone images. In three different projects we tested for learning gain after exposure to our VFTs by using identical pre and post VFT questionnaires. Pandemic restrictions forced us to replace our first-year introductory field trips by VFTs.Key ResultsIn a final assessment testing for understanding of geological principles based on their usage of these VFTs, the assessment results for first year students showed encouraging signs of learning gains. In the second project we exposed second year students, third year students and Honours students as well as graduate geologists to the basic principles of slope stability in engineering geology. In this case we presented a lecture, followed by a questionnaire on the concepts mentioned, followed by the VFT and again the same questionnaire where we demonstrated a distinct learning gain. Finally, we used a lecture on basic characteristics of sedimentary features in turbidite deposits, enhanced by a comprehensive VFT to prepare Honours level students for a weeklong field trip. Comparing their final report with the final report of the previous year’s group of students also demonstrated learning gain.ConclusionWhile we acknowledge that real-life field work can never be replaced, we have demonstrated that properly designed VFTs can be successfully used to enhance learning at real-life field work.
Extension of reciprocity calibration of microphones to frequencies below 1 Hz
Authors: Olsen Erling Sandermann
Published: February 2023

For many years, primary measurement standards of sound pressure have been realized by calibration of laboratory standard, LS, microphones with the reciprocity calibration technique specified in international standard IEC 61094-2. Recent BIPM key comparisons, CCAUV.A-K5 and CCAUV.A-K6, have extended the lower frequency limit of the method from 20 Hz to 2 Hz, but with known uncertainty on the standard’s models of thermos-viscous effects and acoustic impedance of the microphones, which in practice prevented further excursion to lower frequencies. This uncertainty has now been minimized with improved calculation methods that have been included in an amendment to the standard, IEC 61094-2 AMD1. These developments have opened the possibility of reducing significantly the lower frequency limit of the method, subject to practical considerations.A significant advantage of extending the frequency range of the reciprocity technique to the low frequencies targeted in the Infra-AUV project is that it will enable one primary method to cover the entire frequency range of pressure sensitivity from quasi-static pressure variations at 40 mHz, or lower, to 10 kHz for LS1 (one-inch LS) microphones.With the reliable calculations of the acoustic properties of air in cylindrical cavities at low frequencies now available, the dominating challenge of extending the reciprocity technique to frequencies below 2 Hz has been to ensure a very low, and at the same time highly reproducible, cut-off frequency of the necessary static pressure equalization of the cylindrical cavities, couplers, used in the calibrations. Prototype couplers have been developed in the project that solves this challenge. The achieved reproducibility of reciprocity calibrations at frequencies down to 25 mHz and some independent verification of the results will be presented.
Evolution of the hydrothermal fluids of the Yolindi Fe-Cu skarn deposit, Biga peninsula, NW Turkiye: Evidence from carbon-oxygen isotopic variations of calcite minerals
Authors: Kaya Mustafa , Kumral Mustafa , Abdelnasser Amr , Yalçın Cihan , Öztürk Sercan , Bayram Hatice Nur , Tanç-Kaya Beril
Published: February 2023

This work deals recently with the carbon (δ13C) and oxygen (δ18O) isotopic variations in the calcite associated with the hydrothermal mineralization to comprehend the nature of the ore fluid and its source and the evolution of the Yolindi Fe-Cu skarn deposit at North of Biga peninsula (NW Turkiye). The Yolindi area is made up of Torasan Formation (marble, hornfels, phyllite, and schist) which was intruded by Oligocene Hallaçlar volcanic rocks and later early Miocene Şaroluk plutonic rocks. The Yolindi Fe-Cu skarn deposit has been formed along the eastern contact of Şaroluk pluton with the Torasan Formation having widespread prograde and/or retrograde skarn, silicic, and carbonate (calcite) alteration. The prograde skarn is less observed and characterized by formation of garnet with subordinate magnetite. While, the retrograde skarn is highly extensive having epidote, actinolite, chlorite, and carbonate including pyrite, magnetite, chalcopyrite, and specular hematite with subordinate sphalerite and galena. Malachite, azurite, goethite, hemimorphite, and cerussite represent the supergene minerals which locally replaced Fe-oxide and Fe-Cu±Zn±Pb sulfide minerals. At the Yolindi Fe-Cu skarn deposit, carbon and oxygen isotope ratios of calcite minerals from the exoskarn zone are -15.5 to -2.0 ‰ relative to PDB and 0.9 to 17.9 ‰relative to V-SMOW, respectively. Furthermore, it was inferred from the calculated carbon isotopic composition of an ore-forming fluid (δ13CCO2 = -12.7 to +0.8 ‰) that the carbon in the fluid is identical to the reduced carbon in sedimentary and metamorphic rocks. However, the calculated fluid's δ18OH2O values—which vary from 0.9 to 17.2 ‰VSMOW—indicate a mixture of metamorphic and magmatic origins for the hydrothermal fluid. This fluid mixing which has high range of C-O isotopic compositions has been due to a temperature effect along with either CO2 outgassing or fluid/rock interactions. Additionally, the mineralizing fluid is most likely derived from the metamorphic dehydration of carbonate rocks in the Torrasan Formation during Yolindi skarn formation.Keywords: carbon (δ13C) and oxygen (δ18O) isotope; Fe-Cu Yolindi skarn deposit; Biga peninsula; NW Turkiye
Geochemical processes controlling the partitioning of metals between water and sediments / marsh soils in an estuary affected by acid mine drainage leachates
Authors: Pérez-López Rafael , Millán-Becerro Ricardo , Basallote María Dolores , Macías Francisco , Ruiz Cánovas Carlos , Nieto José Miguel
Published: February 2023

All climate change predictions foresee a rise in sea level in the coming decades. Estuaries are environments particularly affected by this change due to their biodiversity. The Estuary of Huelva (SW Iberian Peninsula) is one of the most vulnerable ecosystems on the coastline on a global scale because it represents a transition zone between an acid fluvial environment severely polluted by acid mine drainage and alkaline seawater. Sediments and marsh soils are rich in iron and aluminium precipitates, which are highly reactive due to their nano-particle size. They also act as sinks for numerous pollutants, particularly arsenic. This research focuses its attention on the study of the set of geochemical and mineralogical processes that affect the mobility of metals and the stability of the particulate material under estuarine mixing, especially those processes that would be triggered by a foreseeable rise in sea level. Moreover, this study provides insight into the high contribution of the acid mine drainage discharges to the release of other elements (S, Zn, Cd, Ni and Co) to the coastal areas, as their initial concentrations behaved conservatively in mixing solutions with no participation in sorption processes. Some potentially toxic elements that remain mobile after reaching the estuary, finally end up to the Atlantic Ocean contributing significantly to the total pollutant loads and threatening the environmental conditions of coastal areas. Knowing the stability and mobility of pollutants in the estuarine areas that will be flooded in the next years according to most predictive models of climate change is essential for the design of adaptation strategies and minimization of impacts on the estuarine environment.
 
Acknowledgements
This work was supported by the Spanish Ministry of Science and Innovation under the research project TRAMPA (PID2020-119196RB-C21).
TUdi meta-database of long-term monitored farms and experiments to support soil degradation detection
Authors: Bakacsi Zsófia , Pirkó Béla , Tóth Eszter , Molnár Sándor , Havas Ádám , Gyurics László
Published: February 2023

Within the TUdi project a comprehensive list of long-term monitored farms and experiments have been created in 2022, including basic data on the agricultural system, farm typology, soil and climate,  and soil restoring strategies implemented for European TUdi partners (Austria, Bulgaria, Czechia, Hungary, Italy and Spain) and China. These data and results, in line with the objectives of the project, will contribute to the development of Decision Support Tools available to users to detect soil degradation and provide expert advice on mitigation. The TUdi database contains metadata, structured thematically, allowing insight into the data related to each experimental site (e.g. what purpose experiments are carried out or what type of data is generated in an experiment) and the implementation of queries according to the user's needs. At present, the TUdi meta-database contains the general description of 34 sites (farms and long-term experiment sites), and meta-information on different treatments, management (e,g. conventional, integrated, organic), tillage practices and different experimental settings of around 140 experiments related to these sites. A central element to which the other data are linked is the “site” under which the experiments are subdivided. A smaller part of the data is related to the site, while a larger part is related to the experiments. This is the structural element of the database, which cannot be modified in the future. This structure allows the database to be sufficiently flexible, both to add new sites and to add experiments or measured or calculated parameters that can be further linked to the sites. A query interface is also connecting to the TUdi Database webpage. The filtering options are focusing on the “Degradation threats/challenges” and the “Experiment type/treatment” options. The performance and effectiveness of the queries will be tested when the Partners upload their available experimental data into the system. According to the first query, concerning the main characteristics of the surveyed sites: 70% of the investigated sites are covered by annual crops, 7% are grasslands and the remaining 23% are orchards or olive plantations. 79% of the applied farming system is conventional, 10% organic, 4 % integrated, and the remaining 8% is a combination of them. Mineral fertilizers are used in 60% of the investigated sites, organic fertilizers in 32%, and their combination in the remaining 8%. Irrigation is applied on about one-third of the described sites (38%).Keywordssoil degradation, long term experiments, Decision Support Tool 
Nina and Berry: Using science research and art to deepen children’s and public understanding of our oceans and marine organisms
Authors: Panieri Giuliana , Zimmermann Jane
Published: February 2023

Foraminifera are tiny, single-celled organisms that live in all of our planet's oceans and seas. They are the most abundant single-celled organisms in the marine environment, and despite their small size, they are essential for understanding the evolution of life and ecosystems on Earth. We would like to introduce the world of foraminifera to children and the general public who don't know much about them and their important role in Earth's history in a playful way, where we combine our passion for science and Art.We have created two illustrated mascots called Nina and Berry, which are based on what we now know about foraminifera thanks to micropalaeontology. Nina Floaty is based on a planktonic species that floats in the sea(Neogloboquadrina pachyderma), and Berry Ground is based on a benthic species that lives on the seabed(Melonis barleeanus).They will teach us a better understanding and knowledge of our planet through their stories, which will hopefully make us think about why foraminiferal assemblages might be important for more symbiotic ways forward together in this changing world.
Morphological and geochemical evolution of the eruptive activity along axial volcanic ridges in the Northern section of the Reykjanes ridge.
Authors: Le Saout Morgane , Devey Colin W. , Palgan Dominik , Lux Thorsten S.
Published: February 2023

The Reykjanes Ridge is a segment of the slow-spreading Mid-Atlantic Ridge interacting with the Iceland plume. The 900 km long segment consists in “en echelon” axial volcanic ridges. They are typically 3-6 km wide, 20-30 km long, 200-500 m high, and overlap with each other over a distance of, on average, 1/3 of their length.  The Reykjanes ridge AVRs have been the subject of several studies and are the base of numerous models of AVRs evolution. However, most of these studies are based on bathymetry with a resolution > 20 m and sidescan data > 5 m, with no geochemical component. Thus, small temporal variations of the accretionary processes, especially changes in eruptive activity and magma composition, are still not well constrained. We here retrace the development of AVRs using high-resolution data combined with lava flow composition. During the MSM75 expedition in 2018, four AVRs between 62.95ºN and 63.20ºN were mapped at the resolution of 5 m. At the 63.08ºN AVR, bathymetric and backscatter data are combined with side-scan sonar data (with a 50 cm resolution) acquired with an autonomous underwater vehicle (AUV Abyss from GEOMAR) and near-bottom video from six remotely operated vehicle dives (ROV Phoca from GEOMAR) to: 1) delineate individual lava flows and tectonic structures, 2) determine flow morphologies (i.e., lobate flows, hummocky flows, hummocky ridges, seamounts), 3) locate extrusion sources, and 4) determine the chronology of the geological events. In addition, the composition of samples collected via ROV and wax corer is used to determine the geochemical evolution of the AVR. Around 200 flow units with distinct morphologies and stages of sedimentation were delineated. Our study reveals that major changes in the flow morphology at 63.08ºN is correlated with changes in flow composition. The AVR development appears to have initiated with the emplacement of seamounts aligned along an eruptive fissure. This was followed by a period of relatively high-extrusion rate / low viscosity eruptions leading to the emplacement of lobate flows. A decrease in extrusion rate and/or increase in viscosity results in the transition from lobate to hummocky morphology. In the last stage, the volcanic activity focuses along numerous narrow hummocky ridges. The similarity of the morphology distribution on several neighboring AVRs in this region indicates comparable evolutions.
Climate change impacts on large scale avalanche risk in mountainous regions
Authors: Ortner Gregor , Michel Adrien , Spieler Matthias B.A. , Kropf Chahan M. , Christen Marc , Bühler Yves , Bründl Michael , Bresch David N.
Published: February 2023

The effect of climate change on snow avalanches is widely unknown. Various studies indicate that a rise of temperature  and extreme precipitation events will influence the release and the flow regime of snow avalanches. To compare the consequences of these potential changes on snow avalanche hazard and risk with the current situation, we have developed a framework to model avalanche risk at a regional scale. In a first step, we combined an algorithm to delineate potential release areas using a high-resolution terrain model and a forest layer and modeled three hazard scenarios for the current climate situation in a region in central Switzerland. The runout modelling was carried out with the RAMMS::LSHIM Large Scale Hazard Indication Mapping algorithm implemented in the recently released high parameterised version RAMMS::Extended.For modelling climate change effects on snowfall intensity and snow pack temperature, we used down-scaled data from the Swiss climate change scenarios CH2018 as input for the snow- and surface model "SNOWPACK''. The results of six different model chains within the RCP8.5 emission scenario and a hundred year (from year 2000 to 2100) long data set provided the input to simulate the course of over 600 future winters. For these hypothetical  future winters, we applied extreme value statistics to determine the future changes of the three-day maxima of snowfall. This maxima were used to derive the potential future avalanche fracture depth. We used the output of SNOWPACK for various snow layers to take the effect of changing snow temperatures on the flow regime into account. Furthermore, we considered the rise of the zero degree line to restrict potential future avalanche release zones.The so-derived changing avalanche hazard disposition maps were used as input for the probabilistic, Python-based risk assessment platform CLIMADA to quantitatively assess the risk to buildings. The resulting maps depict the impacts of climate change on snow avalanche risk by highlighting areas where adaptation measures might be needed and thereby provide a basis for risk appraisal options and risk management strategies considering climate change. 
Development of a Carbon Dioxide Raman Lidar
Authors: Schumacher Moritz , Behrendt Andreas , Lange Diego , Wulfmeyer Volker
Published: February 2023

Carbon dioxide (CO2) is one of the most important greenhouse gases and therefore its detailed measurement is of high interest. As the concentration varies significantly with altitude and time, it is desirable to be able to measure vertical CO2 profiles with high temporal resolution. Profiles of high resolution will improve our understanding of atmospheric systems and the impact of the local environment, e.g., due to natural and anthropogenic sources and sinks. The use of these data in data assimilation provides the potential of improving climate models.For water vapor and temperature the Atmospheric Raman Temperature and Humidity Sounder (ARTHUS) system has proven to be able to provide profiles with high resolution (10-60 s in time and 7.5-100 m vertically) and accuracy in the lower troposphere. Now this successful system will be expanded with a CO2 Raman channel, which is currently in development. After successful integration it will be possible to simultaneously measure CO2, water vapor and temperature profiles. Challenges are the weak signal of the backscattered light due to the low concentration and the small Raman backscatter cross section of CO2.Further information on the CO2 Raman lidar will be given at the conference.
Model-based assessment of the effectiveness of Nature-Based Solutions in flood risk reduction: The case of Tamnava River Basin in Serbia
Authors: Ruangpan Laddaporn , Plavšić Jasna , Rosic Nikola , Curran Alex , Pudar Ranko , Vojinovic Zoran
Published: February 2023

Urbanization and climate change are making societies around the world more vulnerable to flooding. Effective and sustainable adaptation measures are needed to counteract the impacts of these changes and Nature-Based solutions have gained considerable attention for both mitigation and adaptation methods of flood risk reduction. However, methodologies to evaluate their performance and upscale their implementation are lacking. Performance evaluation in particular is an important process for decision-makers to be able to decide on the most desirable measures to be implemented. The present research aims to develop a methodology for evaluating the effectiveness of NBS in reducing flood risk. The hydrological model (HEC-HMS) and 1D-2D hydrodynamic model (HEC-RAS) were coupled to create probabilistic inundation depth maps. A detailed flood damage model is then built and applied to estimate damage with and without the measures. The flood damage model was developed within the model builder in ArcGIS so that it can be easily replicated with many scenarios. Four measures were selected for the analyses, namely; reforestation, retention ponds, riparian buffer stripes, and bridge removal. This methodology has been applied to the case study of the Tamnava River Basin in Serbia within the EU-funded RECONECT project.
Change in the Tropical Storms activity in the future over the Ganges basin
Authors: Ali Haider , Fowler Hayley , Roberts Malcolm , Vanniere Benoit
Published: February 2023

The understanding of climate change impacts on tropical storms (TS) activity is crucial for better planning and risk assessment. Despite the theory and modeling suggest an increase in the TS activity with warming, the change in TS characteristics remain uncertain due to the limitations in the global climate models and tracking algorithms (tracker). Here, we performed tracker-inter-comparison and model-evaluation to find out the reliability of trackers and models at simulating the TS characteristics. We found that both trackers produce qualitatively similar results but quantitative different results due to different specifications of the algorithms and model bias. Our results show a decline in the frequency but rise in the strength of TS in the future for the Ganges and the Mekong basin.
How robust are CMIP6 models in predicting Sahel rainfall at decadal time-scales ?
Authors: Ndiaye Cassien , Mignot Juliette , Mohino Elsa
Published: February 2023

Economically based on rain-fed agriculture and grazing, the Sahel region is extremely vulnerable to possible shifts in its rainfall pattern associated with the West African monsoon. Short-term climate prediction, i.e. in the horizon of 5 to 30 years, the so-called "decadal" time scale, is highly relevant for economic and structural planning.In this study we evaluate the impact of model initialization in the skill and reliability with which Sahel rainfall amounts are predicted by different models at decadal timescales. Using initialized and uninitialized (historical simulations) hindcasts from height (8) CMIP6 models and their ensemble mean, our results show that the impact of initialisation depends on the model. Half of the models (MPI-ESM1-2-LR, MRI-ESM2-0, IPSL-CM6A-LR and EC-Earth3) show skillful MSSS scores in their uninitialized experiments and the initialization does not provide further improvements. This situation is very different from the previous coordinated exercise performed within CMIP5 suggesting an enhanced role of external forcing on the interannual to decadal modulation of the Sahel rainfall in CMIP6. However, for NorCMP1 while initialized predictions show skillful MSSS scores, uninitialized ones show very weak scores, suggesting the initialization improves the forced response and the internal variability in this model. Our results also show that the MRI-ESM2-0 model is more skillful than the multi-model ensemble. In addition to MSSS scores, the reliability of these prediction systems is also tested. Preliminary results show positive impacts of the initialization in five out of height models. In general, our results suggest that the initialization does not greatly improve MSSS scores but it does enhance reliability.
Forest-floor litter and deadwood cycle significant amounts precipitation
Authors: Floriancic Marius G. , Allen Scott T. , Meier Raphael , Truniger Lucas , Kirchner James W. , Molnar Peter
Published: February 2023

Forests modulate precipitation and evapotranspiration fluxes. One important – yet often overlooked - component in the forest water cycle is the forest-floor litter layer. Leaves and deadwood retain significant amounts of annual precipitation and enhance subcanopy humidity. At the “Waldlabor Zurich” ecohydrology field site we conducted numerous experiments to quantify the water fluxes from and to the forest-floor litter layer. We estimated the total retention capacities of needle, broadleaf and deadwood litter, assessed the litter water content before and after precipitation events, and measured soil moisture in litter-covered and litter-free plots. We used micro lysimeters to estimate evaporation from the litter layer and measured subcanopy humidity and temperature at different heights above the forest floor to assess the effect of evaporation on subcanopy microclimate.Storage capacities of needle litter and broadleaf litter averaged 3.1 and 1.9 mm, respectively, with evaporation timescales exceeding 2 days, whereas deadwood stored ~0.7 mm of precipitation, and retained water for >7 days. Deadwood water retention increased with more advanced decomposition. Together the forest floor litter layer reduced soil water recharge, reduced soil evaporation rates, and insulated against ground heat fluxes thus impacting snowmelt patterns. Timeseries of deadwood water content revealed a diel cycle of stored water, water content increased during nighttime due to condensation of dew and fog and decreased during the day when vapor pressure deficit and evaporation were high. The water evaporating from the forest‐floor litter layer increased humidity, decreased temperature, and reduced vapor pressure deficit in the subcanopy atmosphere. Although, the absolute amounts of water storage in the forest-floor litter layer are relatively small, these storages were frequently filled and emptied with every precipitation event, thus effecting the overall soil water recharge. Overall, 18% of annual precipitation, or 1/3 of annual evapotranspiration, were retained in the forest-floor litter layer suggesting that overlooking litter interception may lead to substantial overestimates of recharge and transpiration in many forest ecosystems.
Analysis of the inter-satellite ranging pre-fit residuals and of the impact of an IPU failure in GRACE-FO
Authors: Zhu Zitong , Müller Laura , Wang Changqin , Müller Vitali , Yan Yihao , Heinzel Gerhard
Published: February 2023

GRACE and GRACE-FO mapped the monthly time-variable gravity fields with a spatial resolution of ~300km over the past two decades, providing information on mass transport in the Earth system. The twin spacecraft can sense the gravity variability from the low-low inter-satellite ranging system, such as the K-Band ranging (KBR) and the more precise, Laser ranging interferometer (LRI). This poster is divided into two parts, the first part (1) focuses on the features of prefit residuals, and in the second part (2) we analyzed the impact of a complete failure of the Instrument Processing Unit (IPU) in GRACE-FO:(1) The polar-orbit configuration of GRACE/-FO can lead to uneven sampling of Earth observations, which could be manifested as north-south stripes in scientific data. Here, we use prefit residuals which are along orbit and have more flexibility to detect short-lasting signals. Prefit residuals can be deduced from inter-satellite ranging measurements and integrated orbits, with tailored processing strategy. Then we compare the residuals of GRACE-FO KBR and LRI from 2019 to 2021. According to the comparative analysis in the time, frequency and space domains, the results show that both instruments can capture most of the geophysical signals well whereas LRI prefit residuals have lower noise over the ocean area. Additionally, LRI also shows prefit residuals higher than background noise in areas where large signal trends usually occur, such as Greenland, Gulf of Alaska coast and Antarctica. But it is still difficult to capture this high-frequency variability in gravity field recovery. These results indicate that this novel perspective on GRACE-type mission data may improve our understanding of mass distribution changes at particular locations at shorter periods, especially for LRI observations.(2) Since satellite GF-2 of GRACE-FO is already using its redundant Instrument Processing Unit, there is an elevated risk that at some point KBR and GPS observations will become unavailable for this satellite, if the redundant unit breaks as well. In order to assess the impact of such loss, we used a SLR orbit data product provided by GFZ Potsdam to replace the GPS observations from GF-2. With the help of the SLR orbit product we were able to compute the LRI light time correction, and finally derive a LRI1B dataset that would be representative for the situation of an unavailable IPU. We used the data to assess the gravity field quality. Here we show some details on the derivation of the LRI1B dataset and provide the gravity field results.
The impact of forest management on soil microbial community functions in two forests of South Apennines (Italy)
Authors: Picariello Enrica , De Nicola Flavia
Published: February 2023

Forest soils store large amounts of organic matter from aboveground litter. Consequently, practices that affect plant development and soil properties may have crucial impacts on forest ecosystem functions and C feedbacks. In Europe, thinning of forests is a commonly used management practice to promote natural trees regeneration through increasing the temperatures, microbial activity, nutrient availability and irradiance of soil. Forest management influences the occurrence of tree species, the maximum stand density, the organic matter input to the soil decomposer system and hence the availability and quality of microbial resources. Thus, forest management can alter soil microbial community and key ecosystem functions they perform affecting the related ecosystem services, although the functional redundancy of soil microbial communities may minimize these impacts.Due to the importance of forest soils as both sink and potential source of carbon and their predicted sensitivity to climate change, they became in the last years, one of the key targets of microbial ecologists.In the present study, we assess the effects of forest management (coppice and high forest) on soil properties and microbial community functions in two Italian forests (turkey oak and beech), in two different seasons, summer and autumn. We investigated functional diversity of microbial communities based on the carbon consumption patterns (by community-level physiological profile, CLPP, and derived average well color development AWCD) and several enzyme activities linked to biogeochemical cycles of C, N and P.The soil microbial community showed higher metabolic activity in both beech and turkey oak under coppice management (1.32 and 1.54 AWCD, respectively) respect to high forest regime (1.09 and 1.32 AWCD, respectively), only in summer. Significant differences in AWCD values between seasons were found only in forests under high forest management.Among the investigated soil enzyme activities, only hydrolase showed in summer higher value in beech under coppice respect to high forest management (0.41 vs 0.25 mg FDA g-1soil d.w. h-1). This enzyme activity, however, showed higher values in summer than autumn in both forest soils, regardless the management. Hydrolase activity measures the total microbial activity in soil and is a good general index of organic matter turnover in natural ecosystems.The results will provide useful data for: improving the sustainability of ecosystems in a scenario of climate change; identifying new biological indicators of soil health and fertility to predict the effects of forest practices.
Discharge characteristics for different glacier mass balance conditions at Vernagtferner, Ötztal Alps
Authors: Lambrecht Astrid , Mayer Christoph
Published: February 2023

Discharge from glaciers plays an important role for ecosystems, land use and hydropower production in different regions of the world. The discharge hydrograph in glaciated catchments is determined by several parameters, like snow cover, glacier size and glacier mass balance, besides others. Variations in these parameters might considerably change the temporal availability of melt water in such regions, which needs to be taken into account for long term water management planning.Here, we investigate in detail the characteristics of discharge in a highly glaciated catchment in the central eastern Alps. The Vernagtferner basin (11 km² area and 6.9 km² glacier area) is characterised by a high density of monitoring stations, which are an ideal basis for testing and applying models of snow and glacier evolution, as well as discharge simulations. The combination of a gauging station with meteorological observations and continuous monitoring of snow and ice melt at different locations, allows to investigate the major processes in detail. During the period 2019 to 2022 rather different mass balance conditions occurred, which strongly influenced the temporal evolution of the discharge generation. We investigate the significance of snow cover, firn and glacier ice to the melt water generation and the temporal characteristics of the hydrograph.