bluuebunny/crossref_metadata_2025 huggingface dataset:
A climatology of Mediterranean cyclones and compound weather extremes
Authors: Portal Alice , Martius Olivia , Raveh-Rubin Shira , Catto Jennifer L
Published: March 2024

Mediterranean cyclones are the main driver of surface weather extremes in the Mediterranean region. In this work we establish a new procedure for the attribution of different types of meteorological extremes to Mediterranean cyclones, where we also distinguish the presence of different airflows (warm conveyor belts, dry intrusions) and fronts composing the structure of a cyclone. We apply the procedure to a dataset of rain-wind and wave-wind compound extremes extracted from ERA5 reanalysis in a recent climatological period, and show that the majority of weather compounds occurring in the Mediterranean area is indeed linked to the presence of a nearby cyclone. The association of compound rain-wind events with Mediterranean cyclones locally surpasses an 80% level, while interesting differences between transition seasons and winter are detected. Winter cyclones - generally stronger, larger and distinctively baroclinic - are associated with a higher compound density. The de-construction of the cyclone in airflows and fronts evidences a strong association of rain-wind compounds with regions of warm conveyor belt ascent, and of wave-wind compounds with regions of dry intrusion outflow.
The unique 1432–2013 flood marks from the Děčín Castle Rock, Czech Republic, are scanned in 3D and utilized
Authors: Elleder Libor , Kabelka Tomáš , Šírová Jolana
Published: March 2024

Our contribution presents an example of archiving of an invaluable collection of flood marks. With respect to the height of the object carrying these flood marks exceeding 12 metres it is not possible to explore all flood marks in detail in situ. 3D scan, however, offers an excellent possibility how to solve this task. We have analysed the Děčín Castle Rock (further DCR) flood marks in context of their importance, history, recent scanning, reliability check and utilization.  The DCR ranks amongst the most important epigraphic hydrological objects in Europe. Three major reasons for that can be listed as follows: (i) the Děčín town geographical position represents the outflow of the whole Bohemia concentrating the water volume from the upper part of the Elbe river catchment, (ii) the presence of ancient flood marks (the oldest one representing the 1432 flood event) engraved in the sandstone Castle Rock, (iii) the striking relation between the DCR flood marks and the Děčín Hungerstone drought marks situated in its close vicinity  (only some 200 metres apart). It is not the number of flood marks but joint placement of both the flood and drought (low) marks which makes Děčín truly a unique place in European context. The whole flood and drought mark system served as a tool for ancient safe navigation for boats and rafts, and later ships and steamers. We place all these Děčín flood and drought marks in context of other important records in Prague, Litoměřice, and German Pirna, Dresden and Meissen. Furthermore, the oldest water level gauge – estimated to be at least 200 years old - is situated in the same place allowing for direct and easy reading of flood mark heights. Altogether, the Hungerstone drought marks and  DCR flood marks with the old water level  gauge in the Czech town of Děčín  represent an unparalleled complementary system of centennial information for extremely  low and extremely high water levels. Our Map of Extreme Floods (MEF, 2024) application currently offers selected floods the culmination water levels of which are engraved on the DCR, such as July 1432, August 1501, February 1595, February 1682, August 2002 and June 2013, the other will be available sooner (1824, 1890) or later (1771, 1784, 1799, 1830, 1845 and 1862). Reference:MEF, 2024.  Available at:https://chmi.maps.arcgis.com/apps/MapSeries/index.html?appid=dc50b65b4483465cb98c50d4b55df75d. 
Regional Variations of Subsea Permafrost Development on the Arctic Continental Shelves: A comparative analysis of the Beaufort and East Siberian Seas
Authors: Jin Young Keun , Kang Seung-Goo , Choi Yeonjin , Kim Sumin , Hong Jong Kuk
Published: March 2024

The stability and spatial distribution of subsea permafrost across the Arctic continental shelves play a pivotal role in our understanding of global warming. Serving as a significant carbon store, this permafrost has the potential to release greenhouse gases when it thaws, significantly influencing the global climate. This study is dedicated to a comprehensive investigation of the extent and state of submarine permafrost within the Arctic, with a particular focus on the comparative analysis of subsea permafrost development along the continental shelves of the Beaufort and East Siberian Seas. This research enhances our grasp of Arctic subsea permafrost's current variability and its role in global warming processes. To map the extent of subsea permafrost, we utilized multichannel seismic data from the Beaufort Sea (2014) and East Siberian Sea (2016, 2019), collected by the IBRV Araon. Employing a full waveform inversion approach, we precisely determined the seafloor permafrost's velocity structure, offering insights into its depth and state. The research reveals pronounced regional variations in the development of subsea permafrost on Arctic continental shelves. In particular, the continental shelf of the Beaufort Sea is characterized by a densely concentrated distribution of subsea permafrost extending to depths of up to 600 meters. In contrast, the continental shelf of the East Siberian Sea is dominated by permafrost that has thawed significantly, reaching depths of around 400 meters. These different regional patterns may be influenced by a number of factors, including the proximity of the shelf to the coast, the influence of ocean currents, the geological composition of the seabed and the prevailing thermal conditions. These findings suggest that the highly variable nature of submarine permafrost across the Arctic shelf is crucial to understanding warming induced changes in Arctic submarine permafrost and the potential for greenhouse gas release through permafrost dissociation.
Release of ancient dissolved carbon by thawing submarine permafrost in the Canadian Beaufort Sea 
Authors: Chen Nai-Chen , Kim Ji-Hoon , Hong Jong-Kuk , Hong Wei-Li
Published: March 2024

Long-term warming of the continental shelf of the Canadian Beaufort Sea has caused decomposition of submarine permafrost. Ancient dissolved carbon preserved in submarine permafrost could be transported and released into seawater by submarine groundwater discharge derived from thawing permafrost. However, the rate and scale of such a carbon emission is currently unclear. To fill this knowledge gap, we investigate the δ13C, Δ14C, and composition of sediment pore fluid from samples retrieved from a shelf edge site, where rapid seafloor depressions as a result of permafrost thawing have been observed. Downcore decrease of water isotopic signatures indicate widespread meteoric freshwater seepage from the region. The Δ14C values of dissolved inorganic carbon (DIC) in pore fluids indicate an ancient source of DIC (up to 7.7 cal kyr BP). The carbon isotopic mass balance calculation with Δ14C and δ13C of DIC suggest an input of ancient DIC with little radiocarbon, which is not from in-situ dissolution of carbonate. In other words, mixing of DIC from in-situ degradation of local organic carbon and overlying seawater DIC cannot explain the observed Δ14C values of DIC. Based on these results from porewater profiles, we suggest a lateral discharge of low-chlorinity fluid carrying such an ancient DIC to shallow sediments as a result of the decadal degradation of submarine permafrost.
Rates of Change in Past Warm Periods, Part
Authors: Mudelsee Manfred
Published: March 2024

Since the publication of the IPCC's Fifth Assessment Report in 2013, there has been increasing evidence that the social and ecological impacts of global warming depend more on seasonal extremes (e.g. peak summer temperatures) than on trends in annual averages. This is particularly true in the tropics, where extremes have become the greatest threat to ecosystems. However, little is known about the current and future rates of change in means and extremes. Lack of high-resolution data from past warm climates (which serve as analogues) and lack of advanced data analysis methods explain this knowledge deficit.The SEARCH project (Seasonal Extremes and Rates of Change in Past Warm Climates: Insights from Advanced Statistical Estimations on High-Resolution Coral Proxy Records) aims to advance our knowledge by means of (1) using a database of high-resolution coral proxy records and (2) applying advanced simulation techniques from statistical science. SEARCH uses a database of about 50 existing and new (bi-)monthly resolved coral proxy records during the (a) Anthropocene, (b) Medieval Climate Anomaly-Medieval Warm Period, (c) Holocene Thermal Maximum, (d) Last Interglacial and (e) Mid-Pliocene Warm Period.In the first part of our presentation series, we explain the methodological foundations (Mudelsee 2014, 2023): proxy calibration, nonparametric kernel estimation of the first derivative of the climate proxy series and linear regression. The methods take into account typical peculiarities of paleoclimate time series: non-Gaussian distributions, autocorrelation, uneven spacing and uncertain timescales. We present some initial results. Based on the (preliminary) results of SEARCH, we also consider the lessons for navigating the climate future within the framework of the GreenSCENT project (Smart Citizen Education for a Green Future).Acknowledgements:This work has been funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), project number 468589022 (SEARCH), within the SPP 2299, project number 441832482; and by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 101036480 (GreenSCENT).References:Mudelsee M (2014) Climate Time Series Analysis: Classical Statistical and Bootstrap Methods. Second Edition. Springer, Cham. xxxii + 454 pp [https://www.manfredmudelsee.com/book/index.htm]Mudelsee M (2023) Unbiased proxy calibration. Mathematical Geosciences. (doi:10.1007/s11004-023-10122-5).
Comparing EMEP4PL and uEMEP models performance for PM2.5 and NOx for Poland 
Authors: Wisniewska Kinga , Werner Małgorzata , Kryza Maciej , Denby Bruce R. , Fagerli Hilde
Published: March 2024

Nowadays, environmental studies emphasize that the advancement of atmospheric transport models will persist as a significant challenge in environmental modeling for the forthcoming decades. The obtained results are increasingly instrumental in air pollution epidemiology, health burden assessment, and evaluating exposure to air pollution. In this work we have run the regional EMEP4PL atmospheric transport model, with 4km x 4km resolution with high-resolution uEMEP model (250m x 250m) for the area of Poland. The models were run for the entire year of 2022. For the first time, these two models were run using a consistent, high-resolution national emission inventory. We have analyzed two pollutants harmful to population health: PM2.5 and NOx, and qualitatively compared the differences in spatial distribution of pollutant concentrations calculated by uEMEP and EMEP4PL. The uEMEP model shows higher concentrations for the emission hot spot areas, which are averaged out in the coarse-resolution EMEP4PL model. This is observed for both PM2.5 and NOx and is noticeable especially for the areas with large spatial gradient of emission (e.g. large cities or along the main roads). The results were also compared with available measurements of PM2.5 and NOx from the national air quality network operated by Chief Inspectorate for Environmental Protection (CIEP). For PM2.5, we have additionally used the measurements from the national air quality network operated by Chief Inspectorate for Environmental Protection (CIEP) and from the low-cost sensors network established within the LIFE-Mappingair project. The results show that the uEMEP model concentrationsresults are closer to the measurements for both networks. For NOx, uEMEP is also closer to the measurements, and the differences between the uEMEP and EMEP4PL performance are larger if compared to the PM2.5.
Sea surface microlayer mediated exchange between the aerobiome and the Pacific Ocean
Authors: Argaman Meirovich Or , Lang-Yona Dr. Naama
Published: March 2024

Microbes are globally ubiquitous and play a crucial role in ecological network systems and global cycles (e.g., the carbon, nitrogen, water cycles). Hundreds of trillions of microorganisms are estimated to be exchanged between the marine and atmospheric environments, due to the vastness of the sea–air interface. The sea surface microlayer (SML) serves as the interface between the ocean and the atmosphere and is a unique ecosystem for microbial life. The aerosolized microbes may affect ocean ecology, global cycles, and promote genetic exchange between ecosystems. However, little is known about the mechanisms controlling microbial exchange between the environments, and the viable state and metabolic activity of marine bioaerosols. This study aims to characterize the microbial communities of the three environments (surface water-SML-atmosphere) and explore possible linkages between them, by developing a simple and repeatable technique for sampling the SML. We will present the validation of our new SML sampling method, based on surface water sub-sampling, using cell and genomic analyses. This method may provide a substantial improvement compared to direct sampling from the sea, ensuring stabilization without unexpected disturbances. In addition, we will present our results on the linkages between marine, SML and atmospheric microbial communities using our new SML sampling technique, from samples collected in the Pacific Ocean. Our results exhibit different clustering patterns for the three proximal environments, supports their identification as distinct environments with distinct microbial signatures. However, the SML is visualized as an “average” between surface water and air samples both in clustering tightness and location, displays its role as an exchange medium between the ocean water and the marine atmospheric boundary layer. This study contributes to improving understanding of the role of the SML in emission of primary aerosols, leading to better characterization of the ocean-atmosphere interactions and allows for better assessments of their contribution to global cycles and the marine ecosystem.
Temperature-Dependent Shear Strength in Clay Slopes: Experimental Insights and Implications for Stability Assessment
Authors: Loche Marco , Scaringi Gianvito
Published: March 2024

Temperature fluctuations within landslide shear zones can arise from interactions with deeper subsurface layers and the atmosphere crossing the landslide body. Shallow landslides, particularly those with depths less than 10 m, are notably susceptible to seasonal temperature variations and swift climatic shifts. The hydro-mechanical properties of clayey soils exhibit sensitivity to temperature alterations. Some investigations have proposed significant variations in residual shear strength, even within temperature ranges typical of shallow layers in temperate and warm regions.This study examines the response of two pure clays (Ca-bentonite and kaolin) to shearing at temperatures up to approximately 55 °C, considering various normal stresses (50–150 kPa) and shear rates (0.018–44.5 mm/min). A temperature-control system integrated into a ring-shear device facilitated the experimentation.Subsequently, we conducted experiments on an ideal slope to quantify the impact of ground temperature on the stability of clay slopes across seasons and prolonged warming. By accounting for the most substantial effects determined experimentally (residual shear strength changing by ±1.5 %/°C), we identified variations in the global factor of safety of approximately 20% for rotational slides at depths of approximately 6 m, solely due to seasonal heating-cooling cycles. A warming of 5 °C over decades would introduce an additional ±7% change in the stability condition.While acknowledging the simplified geometry and boundary conditions in these results, and the exclusion of triggers, preconditions, and effects of other thermo-hydro-mechanical couplings, they establish an upper limit for the influence of temperature-dependent residual shear strength on the factor of safety. We emphasize that this influence should not be disregarded in slope stability and landslide hazard assessments for clay-rich soils, necessitating thorough experimental analyses and advanced modelling.
Detection of Stick-Slip Nucleation and Failure in Homogeneous Glass Beads Using Acoustic Emissions in Ring-Shear Experiments: Implications for Recognizing Acoustic Signals of Earthquake Foreshocks
Authors: Gou Huaixiao , Hu Wei
Published: March 2024

The acoustic emissions (AEs) produced during the shearing of granular materials reflect the accumulation and release of stress, offering valuable insights into the failure mechanisms of seismic faults and stick-slip-controlled landslides. While various characteristics such as amplitude, energy, counts, and frequency of AE signals generated by stick-slip have been studied, the stress changes corresponding to different frequency AEs at various stages of the stick-slip process remain unclear. This knowledge gap hinders our understanding of the precursory signals leading to stick-slip failure. In order to enhance our comprehension of the physical mechanisms underlying granular stick-slip, we conducted monitoring of both mechanical and AE signals using high-frequency (2 MHz) synchronous acquisition. This was done during the constant-speed shearing of packs containing uniform glass beads of different sizes under varying normal stresses. Our findings revealed an accelerated release rate of AE energy in tandem with sample volume dilatation. Additionally, the stress drop during stick-slip increased with higher normal stress and particle size. This study identified three distinct events during a single cycle of stick-slip: main slip, minor slip, and microslip. We analyzed the AE frequency spectra associated with each of these events. Main slip and minor slip correlated with stress drop, generating high-frequency AEs (approximately several hundred kHz). In contrast, microslip produced lower AE frequencies (around tens of kHz) and exhibited stress strengthening. These characteristics, overlooked in prior studies due to low-frequency acquisition, suggest that microslip is primarily a result of sliding on grain contacts, while main slip and minor slip arise from the breakage and reformation of force chains. The low-frequency AEs from microslip may serve as a crucial precursor to seismic faults and landslides, providing a deeper understanding of the granular stick-slip phenomenon.
Elevation-dependent characteristics of widespread rainfall extremes along the Western Ghats
Authors: Kooran Reji Mariya Joy , Vellore Ramesh , Varikoden Hamza , Tamilselvam Gokul , Krishnan Raghavan
Published: March 2024

Deciphering the rainfall trends over the Western Ghats situated along the west coast of India has been the subject of several recent studies. However, less attention is rendered, particularly to understanding the spatial characteristics of atmospheric features associated with widespread and elevation-dependent extreme rainfall occurrences over this region and this study intends to provide some insights into this aspect. This study observes a rising trend in extreme rainfall events over the Western Ghats during the 1979–2020 period, consistent with earlier investigations. The extreme rainfall events on the windward side located below and above 500 m above sea level exhibit different background circulation signatures, such as mean wind speeds of low-level jets and moist static stability. The extreme rainfall events seen below [above] 500 m above sea level occur in the backdrop of mesoscale [large-scale] monsoon circulation. A Froude number analysis further elucidates the importance of Western Ghats foothill topography in complementing the development and spatial segregation of extreme rainfall occurrences.
Investigating the plate motion of the Adriatic microplate by 3D thermomechanical modelling
Authors: Schuler Christian , Kaus Boris , Le Breton Eline , Riel Nicolas
Published: March 2024

The geodynamic evolution of the Alpine-Mediterranean area is complex and still subject to ongoing debate. The Adriatic microplate motion is of particular interest as it is influenced by three distinct subduction systems: the Alpine subduction in the north, the Dinaric-Hellenic subduction in the east, and the Calabrian-Apenninic subduction in the west. Additionally the system is influenced by the northward movement of the African continent, which further contributes to the geodynamic complexity of the region.In this study, 3D thermomechanical simulations of the Alpine-Mediterranean region are performed using the code LaMEM (Kaus et al., 2016). The simulations employ a viscoelastoplastic rheology and an internal free surface to investigate the internal dynamics of the mantle. The initial plate configuration for the simulations is based on the kinematic reconstructions of Le Breton et al. (2021) at 35 Ma. The objective is to identify the controlling factors that drive the motion of the Adriatic microplate. This is achieved by investigating the role of various model parameters, such as the thermal structure of the lithosphere, the geometry and strength of the continental margin, the mantle viscosity, brittle parameters of the crust and the location of crustal heterogeneities.Results show that Adria undergoes two distinct phases of plate motion over the past 35 million years. Between 35 Ma and 20 Ma, the African plate moves northward, pushing Adria in the same direction. However, once the Hellenic slab rolls back from the east and the Calabrian and Apenninic slabs roll back from the west, the Adriatic microplate decouples from the African plate, resulting in an anticlockwise rotation of Adria. Overall, this study provides valuable insights into the parameters that affect subduction dynamics in the Mediterranean and the independent motion of the Adriatic microplate.Kaus, B. J. P., A. A. Popov, T. S. Baumann, A. E. Pusok, A. Bauville, N. Fernandez, and M. Collignon, 2016: Forward and inverse modelling of lithospheric deformation on geological timescales. Proceedings of NIC Symposium.Le Breton, E., Brune, S., Ustaszewski, K., Zahirovic, S., Seton, M., & Müller, R. D. (2021). Kinematics and extent of the Piemont–Liguria Basin–implications for subduction processes in the Alps. Solid Earth, 12(4), 885-913.
Advancing Real-Time GNSS Single-Frequency Precise Point Positioning through Ionospheric Corrections
Authors: Reuveni Yuval , Landa Vlad
Published: March 2024

Real-Time Single-Frequency Precise Point Positioning (PPP) is a cost-effective and promising method for achieving highly accurate navigation at sub-meter or centimeter levels. However, its success heavily relies on real-time ionospheric state estimations to correct delays in Global Navigation Satellite System (GNSS) signals. This research employs the Dynamic Mode Decomposition (DMD) model in conjunction with global ionospheric vertical total electron content (vTEC) Root Mean Square (RMS) maps to create 24-hour forecasts of global ionospheric vTEC RMS maps. These forecasts are integrated with C1P forecast products, and the performance of L1 single-frequency positioning solutions is compared across various ionospheric correction models. The study assesses the impact of assimilating predicted RMS data and evaluates the practicality of the proposed approach using the IGRG product. The results demonstrate that the IGSG RMS prediction-based model significantly enhances positioning accuracy for up to five hours ahead, yielding results comparable to alternative models. This approach holds promise for achieving high precision navigation.
High-resolution drought monitoring with Sentinel-1: A case-study over Mozambique
Authors: Massart Samuel , Vreugdenhil Mariette , Hahn Sebastian , Muguda Sanjeevamurthy Pavan , Villegas-Lituma Carina , Wagner Wolfgang
Published: March 2024

Droughts are characterized by periods of below-average precipitation leading to an imbalance in the hydrological cycle and reduced water availability.In the last decades, higher average temperatures and shifts in annual rainfall patterns have increased the frequency, intensity, and length of droughts across the globe.With the majority of its population living in rural areas and a high economic dependency on rain-fed agriculture, Mozambique is particularly vulnerable to droughts, as water shortages have devastating environmental, agricultural, and economic impacts. Therefore, monitoring droughts in Mozambique is key to developing early warning systems and adequate planning for drought impact mitigation.In this study, we propose a novel approach to retrieve a drought index at a kilometer-scale resolution based on surface soil moisture (SSM) products derived from Sentinel-1 (S1) and ASCAT. First, both SSM products are processed over the Mozambican region using a change detection method (Sentinel-1 sampled at 1km and ASCAT at 6.25km) and compared to SSM from ERA5-Land. Then, by combining the long-term ASCAT data record with the high spatial resolution of Sentinel-1, we generate a monthly kilometer-scale drought index for the period 2016 to 2023 over six study areas located in South-central Mozambique (Chokwé, Mabote, Massinga, Buzi, Muanza and Govuro). The S1-ASCAT indicator is then evaluated against state-of-the-art drought indices based on precipitation data (Standardised precipitation index from CHIRPS (Rainfall Estimates from Rain Gauge and Satellite Observations)) and vegetation data (Normalized difference vegetation index from the Copernicus Global Land Service.This study explores the potential of high-resolution SSM based on active microwave remote sensing to monitor agricultural droughts. Our results show that a drought indicator based on Sentinel-1 and ASCAT can temporally and spatially capture sub-regional drought patterns over Mozambique.
Consequences of Impact Erosion and Volatile Loss Processes on the Evolution of Venus.
Authors: Gillmann Cédric , Golabek Gregor
Published: March 2024

We model the long-term evolution of Venus through volatile exchanges and compare observed and simulated present-day states. This work focuses on quantifying the effect of different parameterizations for loss processes on the overall evolution.Due to both the striking similarities and the obvious differences between Earth and Venus, understanding Venus might hold keys to how planets become -and cease to be- habitable. It has been suggested that the divergence between Earth and Venus could occur during the first few hundred million years due to interaction between the interior of the planet, its atmosphere and escape mechanisms. We develop coupled numerical simulations of the atmosphere and interior to test what evolutionary paths can reproduce the observed present-day state of Venus. They include modeling of mantle dynamics, core evolution, volcanism/outgassing, surface alteration, atmospheric escape (hydrodynamic and non-thermal), volatile deposition and loss through impacts. Impact histories representing different possible scenarios for late accretion are generated using n-bodies simulations.Our previous efforts used hydrocode results to model impact erosion. A new parameterization has since been proposed by Kegerreis et al. (2020), with increased losses for high-energy collisions. We test if these results induce divergences between different impact histories (e.g., giant impact vs. small impactors) and combine these different parameterizations depending on impactor size.Post-hydrodynamic escape, non-thermal loss mechanisms can remove low amounts of water and oxygen, from the surface/atmosphere (4 mbar to a few bar), making it quite difficult to accommodate large bodies of water, especially during Venus’ recent past. Trapping oxygen on the surface through oxidation of newly emplaced volcanic material through solid-gas reactions appears inefficient (totalling loses similar to non-thermal escape). Runaway greenhouse resulting in a molten surface could lead to the loss of multiple bars of oxygen but still leaves behind a significant atmospheric inventory. These results imply a maximum limit to water delivery by impacts.Atmospheric delivery and erosion by impacts seem to be the largest source/sink of volatile species during evolution. The choice of parameterization for erosion can induce a large difference in total inventory (up to several 1-10 bar of H2O and CO2). However maximum delivery by impactors over Late Accretion are still limited by loss processes. Previously obtained upper limits for water content of the Late Accretion (95-98% dry enstatite chondrite, 2-5% of carbon chondrite) are revised upward to 5-10% Carbon chondrites for efficient atmospheric erosion models.
A new low latency and low-cost force-balance accelerograph for earthquake and structural monitoring and for early waring applications.
Authors: Germenis Nikos
Published: March 2024

GEObit Instruments are proud to announce the market release of a new low-cost and low -latency seismic accelerograph, the GEO-T200, for earthquake monitoring, early waring applications, and structural monitoring. The device mainly consists of two sections, the triaxial sensor sensor and the digitizer. The architecture and the hardware is based on the GEObit GEOtiny platform.The sensing elements are based in a re-designed previous generation GEObit force balance acceleration sensor unit [1], providing very high dynamic range 160+dB, and wide bandwidth, flat response DC to 260Hz. The acceleration range is user configurable and can be set between +/-4g to +/-0.5g but other ranges are also available upon request.The digitizer is based on a 24bit ADC and provides high effective dynamic range 140dB, high sampling rate up to 4000sps, integrates seedlink server and the earthworm chain. The device is based on a locally running open-source components ported on ARM Linux board. It is able to apply local signal processing and trigger detection based on multiple schemes (amplitude, STA/LTA etc.) through open-source components ported from the Earthworm toolchain and transmit pick times over MQTT with ultra-low latency based signaling for trigger event distribution supporting multiple centralized or distributed schemes.It Supports ethernet port and Wi-Fi. Also supports continuous data stream, triggered data stream (level, LTA/LTA, both) or both.The device is housed into a small cylindrical enclosure, aluminum made, IP68 with dimensions 120mm diameter and 143mm height. Three leveling legs are provided along with a central bolt for proper mounting of the device. An bright OLED lcd screen reports the user about the instrument operation and state of health. The SOH stream is also transmitted in real time over TCP. References:[1]: Design, Modeling, and Evaluation of a Class-A Triaxial Force-Balance Accelerometer of Linear Based Geometry” N. Germenis, G. Dimitrakakis, E. Sokos, and P. Nikolakopoulos Seismol. Res. Lett. 93, 2138–2146, doi: 10.1785/0220210102
Quantifying snout marginal bedload export from alpine glaciers
Authors: Wolf Eva , Dietze Michael , Lane Stuart
Published: March 2024

Bedload export from Alpine glaciers by rivers is a geomorphological process of increasing interest given the high retreat rates of temperate ice masses in the context of global warming. Access and measurement difficulties make it very poorly known and contradictory hypotheses exist about how it might respond to receding glaciers. In subglacial channels, bedload transport is a key mechanism for evacuating one of the products of glacial erosion. It likely constrains glacial erosion rates as removal of the products of erosion is needed so as to yield fresh bedrock for further erosion. Environmental seismology may be a valuable tool in understanding rates of subglacial bedload export.Previous studies have considered subglacial bedload export in glacial forefields using seismic sensors and tracked particles moving underneath the ice sheet. We are taking former studies forward and extend the monitoring of bedload export detecting coarse grain impacts using seismometers right at the glacial terminus. The project aims to determine diurnal as well as seasonal sediment export quantities and compare results among different field sites.We studied subglacial bedload export for the Otemma and Arolla glacier in Valais, Switzerland in the summer of 2023 by installing two seismic stations (PE-6/B geophones) close to each glacier terminus throughout the melt season. These four-month records of seismic signals were processed using fluvial inversion algorithms of the eseis package implemented in R. The algorithm is refined with wave propagation- and ground properties determined through active seismic experiments as well as measured grain size distributions from field sampling. We are able to separate turbulent water noise and bedload noise in the seismic signal and estimate water stage as well as bedload transport rates. Results are validated by comparing the water stage estimates to measurements from a discharge gauging station. Over a full season, we compare the behaviour of the two different glaciers regarding sediment export taking into account their size, orientation, elevation and other factors. We relate the detected bedload export events to meteorological conditions and shifts in seasonal melt processes from snow melt to ice melt.The results of this study help to get a clearer picture of diurnal as well as seasonal patterns of bedload export from glaciers, impacting downstream riverbed erosion and deposition in the light of increasingly rapid glacier melt. These geomorphological processes are of interest for different infrastructural facilities such as hydropower plants.
Combining observations and a high-resolution climate model for the generation of spatial rainfall return levels
Authors: Poschlod Benjamin , Koh Jonathan
Published: March 2024

Rainfall return levels are guiding hazard protection, insurance models, infrastructure design, construction, and planning of cities. When deriving information about the frequency and intensity of extremes by fitting extreme value models to pointwise observations, the regionalization of these models is challenging. Rain gauges are distributed unevenly, where some regions suffer from data scarcity in space and time. To address this, topographical and/or climatological covariates are often used for the spatial interpolation. On the other hand, high-resolution climate simulations are available to provide spatial information on rainfall extremes. However, these simulations are still governed by model biases, where the bias adjustment of extremes at ungauged locations is also inducing uncertainty.   In this study, we propose a combination of observations and a high-resolution convection-permitting climate model simulation in the framework of smooth spatial Generalized Extreme Value (GEV) models in order to estimate spatial rainfall return levels. We choose a study area over southern Germany with complex terrain, which is densely monitored with 1132 rain gauges providing more than 30-year daily rainfall observations. There, a 30-year simulation of the Weather and Forecasting Research (WRF) model is available at 1.5 km resolution driven by ERA5 reanalysis data. We combine observations and covariates from the WRF simulation in the spatial GEV and refer to this approach as sGEV-WRF.We want to answer three research questions to assess the added value of the proposed framework:Is it worth the effort? Does the sGEV-WRF improve the generation of rainfall return levels compared to the WRF alone?
Does the WRF simulation as covariate add value? Can the sGEV-WRF outperform a topography-only spatial GEV?
Does the dynamical downscaling at high resolution add value? Can sGEV-WRF outperform a spatial GEV based on observations and covariates from the coarser resolution ERA5?
By evaluating the percentage bias, mean absolute error, and root-mean-square error, we show that the combination of observations and WRF can improve the representation of 10-year and 100-year return levels of daily rainfall.In addition, we aim to assess the performance of this framework under data-scarce conditions. Therefore, we devise an extensive cross-validation study. We select 5%, 10%, 20%, 50%, 80%, 90%, and 95% of all 1132 rain gauges to re-build the spatial GEV models with 1000 random folds each. We show that the performance is robust under these conditions, highlighting the potential for the application in data-scarce regions. Furthermore, in a non-stationary setup with climate model future projections, it can serve as a reliable tool to assess climate change effects on heavy rainfall.     
Improving the spatial resolution of global mass changes observed by GRACE(-FO) using deep learning — from terrestrial water to the ocean
Authors: Gou Junyang , Börger Lara , Schindelegger Michael , Soja Benedikt
Published: March 2024

Gravity field solutions from the Gravity Recovery and Climate Experiment (GRACE) and its follow-on (GRACE-FO) satellite mission provide an essential way to monitor mass changes in the climate system, comprising terrestrial water storage (TWS) anomalies and ocean bottom pressure (OBP) fluctuations. However, the coarse spatial resolution of the GRACE fields blurs important spatial detail, such as OBP gradients or mass fluxes in individual catchments. By contrast, classical hydrological or ocean models provide small-scale mass change information but of doubtful accuracy, especially for trends. To combine the strengths of both data sources, we develop a self-supervised data assimilation algorithm based on deep learning concepts and apply it successfully to global TWS and OBP anomalies. The specific design of the loss function allows the model to be optimised without requiring a high-resolution ground truth. Instead, the model parameters are optimised by weighing monthly GRACE(-FO) and numerical model inputs according to their respective advantages (i.e., spatial scales where their fidelity is highest). We obtain downscaled TWS and OBP anomaly maps with grid spacings of 0.5° and 0.25°, respectively, preserving reasonable large-scale agreement with monthly GRACE(-FO) fields. We validate our downscaled products on various time scales against satellite altimetry-measured water levels, tide gauge data, and in-situ bottom pressure measurements. The downscaled products facilitate analyses beyond the nominal GRACE(-FO) resolution, including closing the water balance equation in small basins or monitoring coastal ocean mass changes. Over the terrestrial water, our downscaled product provides an average improvement of 0.79 in terms of Nash–Sutcliffe efficiency (w.r.t. ERA5-Land water budget components) for the basins smaller than the effective resolution of GRACE(-FO) missions. Over the ocean, our downscaled product agrees better with coastal tide gauge measurements at more than 78% of studied stations. We anticipate our approach to be generally applicable to other GRACE(-FO) level-3 products and other gridded Earth observation data.
Persistence and the practical predictability of surface temperatures
Authors: Holmberg Emma , Tietsche Steffen , Messori Gabriele
Published: March 2024

Extreme temperature events can cause severe disruptions to society from negative health consequences to infrastructure damage. Early warning systems are a key element in the mitigation of such impacts, with literature highlighting the potential societal benefit of information from sub-seasonal forecasts. We investigate the relationship between the persistence of an atmospheric state and the practical predictability of surface temperatures focusing on medium to extended range time scales. Persistence is assessed objectively leveraging techniques from dynamical systems theory whilst practical predictability is defined in terms of the forecast error in surface temperature. Atmospheric persistence provides potential value for the practical predictability of temperature in some cases with the results varying depending on season and location. Wintertime temperature forecasts at lead times up to three weeks, and cold spell forecasts up to two weeks in lead time are highlighted as cases where persistence appears to show an association with practical predictability.
Compositional heterogeneity within the mantle beneath the South China Sea
Authors: Huang Xiao-Long , Yang Fan , Cai Yu-Xin , Xu Yi-Gang , Ge Zhen-Min
Published: March 2024

The recycling of crustal materials is widely recognized as the primary mechanism driving compositional heterogeneity within the mantle. Seismic tomography has revealed stagnant slabs in the mantle transition zone (MTZ) beneath the South China Sea (SCS), indicating the significant presence of recycled oceanic crust (ROC) in its upper mantle. However, the extent to which recycled crustal materials contribute to the mantle source of mid-ocean ridge basalts (MORBs) remains a subject of debate, as radiogenic isotopes alone yield ambiguous insights. Here, we present comprehensive data on whole-rock major element, trace element, and Mo–Sr–Nd–Hf–Pb isotopic compositions for MORB samples from International Ocean Discovery Program Expedition 349 sites U1431E and U1433B in the eastern (ESB) and southwestern (SWB) subbasins, respectively, of the SCS. The δ98/95Mo values of the SCS MORBs exhibit a significant range (from −0.80‰ to +0.05‰), in contrast to the restricted composition observed in MORBs (δ98/95Mo = −0.19‰ ± 0.01‰). Specifically, the ESB MORBs display extremely light Mo isotopic compositions with Nd–Hf isotopic compositions similar to those of Pacific MORB, whereas the SWB MORBs show slightly higher δ98/95Mo values and depleted Nd–Hf isotopic compositions. The subbasin-scale mantle heterogeneity in the SCS can be best explained by varying degrees of interaction between a mantle plume and stagnant slabs in the mantle transition zone. The rigid stagnant slab in the mantle transition zone beneath the SWB largely impeded the upwelling of the mantle plume, whereas the slab beneath the ESB was disrupted by the plume and subsequently transported into the upper mantle. Furthermore, the SCS MORBs exhibit enriched Sr and Pb isotopes, indicating the incorporation of terrigenous sediment components in the upper mantle beneath the SCS. Continuous subduction preceding seafloor spreading has facilitated the substantial incorporation of subducted crustal materials into the upper mantle or as stagnant slabs within the MTZ of the SCS. The SCS underwent a rapid transition from continental rifting to seafloor spreading, enabling significant preservation of ROC in the upper mantle or as stagnant slabs in the MTZ. Therefore, mantle recycling in marginal sea basins exhibits distinct characteristics compared to that occurring in open oceans.
Inverse Modeling of Air Pollutant Emissions Using Drone-based Air Monitoring Data
Authors: Yun Hui-Young , Han Seung-Hee , Wang Kyung-Hui , Kim Dong-Geon , Jeong Peel-Soo , Son Eun-Seong , Kim Hyeun-Soo , Kim A-Leum
Published: March 2024

Landfill gas, a major contributor to air pollution, results from anaerobic microbial decomposition of organic matter in waste. Classified as a greenhouse gas, it comprises over 99% methane and carbon dioxide, contributing to approximately 3–4% of annual anthropogenic methane emissions. Landfills also release particulate matter (PM), carbon dioxide, non-methane volatile organic compounds, nitrous oxide, nitrogen oxides, odorous substances, and carbon monoxide.In Korea, landfill emissions calculations primarily measure surface emissions using a flux chamber directly on the landfill surface or employ the First Order Decay (FOD) method. However, the method of measuring surface emission cannot simultaneously measure emissions that occur irregularly over a large area, and the FOD method also has the problem of making it difficult to accurately calculate the landfill gas generation rate constant (k) that reflects landfill characteristics. To address these issues, a supplementary approach to emission estimation is being introduced. This involves measuring microclimatic conditions and air pollutant concentrations within and around landfills, coupled with the application of atmospheric dispersion modeling techniques. This method, known as inverse modeling, aims to estimate emissions by accounting for irregularly occurring emissions over extensive areas.This study aims to employ drones to measure air pollutants concentrations occurring irregularly over extensive areas and subsequently perform inverse modeling using atmospheric dispersion modeling. In terms of measurement method, drones have the advantage of being able to obtain data on air pollutants in a short period of time at altitudes and wide ranges that other equipment cannot access. By using Drone-based Air Monitoring, particulate matter, carbon dioxide, methane, Nitrogen Dioxide, Various measurements were made, including volatile organic compound, ozone, and water vapor concentrations. Utilizing the data collected through these measurements, inverse modeling with the CALPUFF model is intended. The CALPUFF model can represent changes in the wind field over time and space through the movement of the puff, and can relatively accurately implement the same unsteady state as the real thing. By using this to calculate emissions by performing ineverse modeling, it is expected that the accuracy of calculating methane gas and fine dust emissions from landfills will be improved. AcknowledgmentsThis research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute (KEITI) funded by the Ministry of Environment (MOE)  
Unreal field trips? Gamification as key for unlocking the potential of virtual geological fields trips.
Authors: Thomann Jan Alexander , Toy Virginia , Hawemann Friedrich , Martínez-Pérez Carlos
Published: March 2024

Geological field work remains an essential part of geoscience education. The close-up, in-situ experience of geological excursions, allow the observation of our study object in 3D as well as in different scales – an immersion unattainable with classical classroom teaching. Despite the undeniable advantages of field-based teaching, it remains mentally, financially and physically challenging for everyone and inaccessible to some of us. In recent years, more and more “virtual field trips” were developed in the hope to transmit as much of the field experience as possible. The development of interactive virtual field trips is very similar to video game design, and yet the outcome is often far away from exciting, interactive, 3D video game worlds. We therefore attempted to stick to classical tools of video game design, such as the 3D modelling software ‘Blender’ and the ‘Unreal Engine 5’, one of the world's leading engines for video games. In this case study, we created a digital twin of an outcrop of Mesozoic sedimentary rocks using photogrammetry, to achieve a photorealistic 3D environment. Movement and interaction in this world are identical to classical, first-person perspective video games, a familiar setup for most students. The user can move around freely, discover hidden fossils and is guided towards the highlights of the outcrop.This gamification approach was developed for university students, but with small modifications it could also be employed in outreach situations, such as in teaching in schools or as part of museum exhibitions where an interactive system can be more engaging than a static or linear system and can target an audience group that is not primary interested in the exhibition but attracted by the gamification aspect.