bluuebunny/crossref_metadata_2025 huggingface dataset:
Gravity and spontaneous potential studies for volcano monitoring in Tenerife (Canary Islands)
Authors: Álvarez Hernández Aarón , Stoker Emily , Neves Danilo Borges , Reyes López Ángel , Ortega Ramos Víctor , Jiménez-Mejías María , Martínez van Dorth David , García Rubén , D’Auria Luca , Pérez Nemesio M.
Published: March 2024

Gravimetry and self-potential are passive geophysical techniques that can contribute to volcanic monitoring. The gravimetric method measures variations in the Earth's gravitational field due to density changes, which could be caused, for example, by magmatic intrusions and fluid accumulation. On the other hand, the spontaneous potential methods measure variations in the natural electric potential generated by the circulation of hydrothermal fluids related to the volcano dynamics. This technique is very useful to delineate the areas affected by hydrothermal activity. Combining both methods offers an integral perspective by detecting variations in mass distribution and natural electrical phenomena within the volcano. Therefore, their application allows us to see changes in the subsurface due to volcanic activity.Applying these geophysical techniques in an active volcanic area could help better understand the temporal evolution of the volcanic activity. In this context, Tenerife represents the perfect scenario for applying these methods. This island consists of three ancient inactive volcanic systems (Anaga, Teno and Roques del Conde) located at the ends of the island, connected by three young rift zones to the center of the island where a giant volcanic caldera, known as Las Cañadas, is located. Inside the caldera and dominating the horizon is the Teide stratovolcano, which has a height of 3718 meters. The crater of Teide hosts intense hydrothermal activity with fumarole and relevant diffuse degassing.For this purpose, since 2018, several gravimetric and spontaneous potential campaigns have been conducted each month on the island: from one side, 60 points spread over the three volcanic ridges, the caldera and the volcanic edifice of Teide were measured using a CG-6 Autograv™ Gravity Meter from SCINTREX. From the other side, 38 points distributed inside Teide’s crater were measured using a V-FullWaver datalogger from IRIS Instruments. The preliminary results show stable values for gravity, while for spontaneous potential, there are significant variations of the geoelectrical values due to variations in the hydrothermal activity.We show how the continuous measurement of these parameters in time could contribute to the early identification of potential volcanic events in Tenerife, which is considered the island with the highest volcanic risk in the Canary Islands.
TimeSpatData: An R Package for Spatio-temporal DataProcessing, Analysis, and Visualization
Authors: Lei Kan , Dürr Hans , Flörke Martina
Published: March 2024

With the rise of high-resolution climate products and a growing influx of observed hydrological data, the demand for efficient tools capable of managing extensive, multi-dimensional datasets has become crucial. Established tools such as Climate Data Operators (CDO), though valuable, are hindered by their command-line nature, limiting their adaptability to advanced spatial and statistical analysis requirements.
Enter TimeSpatData, an R package designed to offer a comprehensive solution for the efficient processing, analysis, and visualization of NetCDF-based spatio-temporal multidimensional data. Tailored to handle large datasets, it integrates additional spatial and temporal information vital for indepth analysis and modeling. Noteworthy for its capability in spatial processing, the package provides functionalities including reprojection, clipping, and masking. Beyond fundamental operations, users can extract and reformat raster or vector-based time series to polygon-based time series, sample data to point-based time series, or interpolate missing values in both time and spatial dimensions. Other analytical applications include spatial and temporal statistics, time series analyses and their combination. The integration of Shiny-based web tools adds a dynamic and interactive dimension to the visualization of temporal, spatial, and statistical information.
In conclusion, TimeSpatData emerges as a versatile, efficient, and user-friendly toolkit for researchers and analysts dealing with complex spatio-temporal datasets. Ongoing developments will focus on expanding functionalities, supporting additional data formats, and refining user experiences, thereby contributing to a dynamic landscape of climate research and hydrological modeling.
Fire hazard trajectories under climate change and management scenarios
Authors: Rodrigues Marcos , Gelabert Pere , Lamelas Teresa , Hoffrén Raúl , de la Riva Juan , Domingo Darío , Vega-García Cristina , Ibarra Paloma , Ameztegui Aitor , Coll Lluís
Published: March 2024

In this work we showcase the in-progress results from the FirePATHS project (PID2020-116556RA-I00). The project aims to assess the evolution of fire danger under different emission and forest management scenarios through the explicit interaction of the climate-vegetation-fire system. For this purpose, a methodological framework combining different simulation models of the elements of this system is proposed. The core of the process lies in the modeling of vegetation dynamics at stand scale according to different trajectories of climatic evolution to characterize the state and typology of fuels and the subsequent simulation of potential fire behavior during the 21st century.We analyzed a set of 114 Pinus halepensis plots, surveyed in the field during 2017;  68 plots burned during the summer of 1994 and 46 unburned control stands. We used the medfate model to simulate forest functioning and dynamics, which provides the necessary fuel model parameters to be entered into fire behavior models (Fuel Characteristics Classification System, implemented in medfate as well). The combination of these two approaches provides time-varying estimates of fire behavior metrics (e.g., flame length or rate of spread). The simulation was conducted under SSP climate scenarios (SSP 126, 245, 370 and 585) depicting different levels of climate warming, vegetation dynamics and, hence, fire danger. Likewise, we devised a set of forest management prescriptions aimed at reducing climate vulnerability of tree communities and reducing extreme wildfire potentials. A baseline scenario with no management was also assessed.We observed very contrasting trajectories between burned and control stands, with the first leading to increasing fuel loads, except in SSP 585. Fire potentials depicted a significant increase in surface fire behavior, with adaptive and mitigation management being able to mitigate it to some extent.
Relocations of earthquake hypocenters in and around the source area of the 2024 Mw 7.5 Noto Peninsula earthquake, Japan, by Bayesian inference
Authors: Shiina Takahiro , Horikawa Haruo , Imanishi Kazutoshi
Published: March 2024

A large crustal earthquake (Mw=7.5) struck the Noto Peninsula, central Japan, at 16:10 (JST = UT + 9 hours) on New Year's Day, 2024. The main-shock rupture extended ~150 km in length, which covered the source regions of intense swarm activity in the northeastern tip of the peninsula [Amezawa et al., 2023] as well as the previous large crustal earthquakes such as the 2007 (Mw=6.7) and 2023 (Mw=6.3) events. The aftershock distribution of the 2024 event provides fundamental information for understanding the rapture process of the main shock and seismotectonics in the Noto peninsula. Therefore, we relocated the earthquake hypocenters that occurred immediately after the 2024 event by considering the three-dimensional velocity structure [Matsubara et al., 2022]. In the relocation, we applied the method proposed by Shiina and Kano [2022] to the arrival time data on the earthquake catalog compiled by the Japan Meteorological Agency. The applied method utilized the Markov Chain Monte Carlo technique, allowing us to evaluate uncertainty in hypocenter locations. Thus, we can discuss the distributions of the crustal earthquakes in and around the source area of the 2024 event, taking account of the spatial variations in uncertainty in the hypocenters. For example, some aftershocks occurred offshore, indicating that estimation accuracy in that area may get worse due to limited station coverage compared with the inland area. As the result of the relocation considering the three-dimensional structure, the depth of these offshore events was shifted about 5 km shallower. These hypocenters suggested that the aftershocks of the 2024 event occurred mainly between the ground surface and the depth of 15 km.
The High-Energy Tail of Energetic Electron Precipitation: Solar Wind Drivers and Geomagnetic Responses
Authors: Salice Josephine , Nesse Hilde , Partamies Noora , Kilpua Emilia , Kavanagh Andrew , Decotte Margot , Babu Eldho , Smith-Johnsen Christine
Published: March 2024

Compositional NOx changes caused by energetic electron precipitation (EEP) at a specific altitude and those co-dependent on vertical transport are referred to as the EEP direct and indirect effect, respectively. The direct effect of EEP at lower mesospheric and upper stratospheric altitudes is linked to the high-energy tail of EEP (>300 keV). The relative importance of the two effects on NOx and their subsequent impact on ozone and dynamical changes at these altitudes remains unresolved due to inadequate particle measurements and scarcity of polar mesospheric NOx observations. An accurate parameterization of the high-energy tail of EEP is, therefore, crucial. This study utilizes EEP flux data from MEPED aboard the POES/Metop satellites from 2004 - 2014 to distinguish >30 keV events from >300 keV events. Data from the Northern and Southern Hemispheres (55-70oN/S) are combined in daily flux estimates. Flux peaks above the 90th percentile of the >30 kev flux are identified. The 33% highest and lowest associated responses in the >300 keV fluxes are labeled "E3 events" and "E1 events", respectively, resulting in 55 events of each type. A sub-selection of "overlapping events" is created based on similar >30 keV fluxes responses. Superposed epoch analysis of mesospheric NO density from SOFIE confirms an observable direct impact on lower mesospheric chemistry associated with E3 events. Elevated solar wind speeds persisting in the recovery phase of a deep Dst trough are characteristic of E3 events. A probability assessment identifies specific thresholds in the solar wind-magnetosphere coupling function (epsilon) and the geomagnetic indices Kp*10 and Dst, crucial for determining the occurrence or exclusion of E1 and E3 events. This study provides insight into which parameters are important for accurately modeling the high-energy tail of EEP.
Improving dispersion measurement using weighted stacking based on polarization analysis
Authors: Guan Bo , Xia Jianghai
Published: March 2024

Retrieving surface waves using linear arrays is becoming gradually popular in urban areas with abundant anthropogenic noise [Mi et al., 2020]. Dispersion measurements can be problematic due to the presence of off-line noise sources. We use the polarization analysis of three-component noise recordings to estimate the back-azimuth and intensity of sources for linear arrays. The noise segment where the source locates in the stationary-phase zones (SPZs) is retained and the noise cross-correlation function (NCF) is weighted according to the source intensity. In this way, we obtain accurate virtual shot gathers and dispersion images.A single three-component seismic station can simultaneously record vertical, north, and east displacements. The back-azimuth and intensity of a noise source within a time segment can be estimated by the relationship between the vertical-horizontal cross-spectra [Takagi et al., 2018]. In practical applications, we remove the mean and trend of the raw three-component noise recordings and divide them into multiple segments. We use the polarization analysis for each segment to locate the orientations and intensities of the noise sources. We then average the results obtained at multiple stations in a linear array to obtain more robust results. We retain the noise segments where the noise sources are distributed in the SPZs and perform weighted stacking of their NCFs according to the intensities of the noise sources in these segments to obtain the final NCF and perform the subsequent dispersion measurement. We use a synthetic experiment and two field examples to demonstrate the superiority of our proposed method. After using the proposed method, the NCFs become more accurate with a higher signal-to-noise ratio, and the trend of the dispersion energy is more continuous. Takagi, R., Nishida, K., Maeda, T. & Obara, K., 2018. Ambient seismic noise wavefield in Japan characterized by polarization analysis of Hi-net records. Geophysical Journal International, 215, 1682–1699. doi:10.1093/gji/ggy334Mi, B., Xia, J., Bradford, J.H. & Shen, C., 2020. Estimating near-surface shear-wave-velocity structures via multichannel analysis of Rayleigh and Love waves: an experiment at the Boise hydrogeophysical research site. Surveys in Geophysics, 41, 323–341. doi:10.1007/s10712-019-09582-4
A few hundred catchments later – lessons learned from modeling large catchment samples
Authors: Seibert Jan , van Meerveld Ilja , Vis Marc , Clerc-Schwarzenbach Franzisca , Pool Sandra
Published: March 2024

Traditionally, hydrological models are applied to one or a few catchments because preparation of the input and calibration data for a more extensive set of catchments is challenging. The availability of data sets with hydrometeorological time series for large numbers of catchments has been a game changer in hydrological catchment modeling in recent years. One example are the CAMELS data sets with the basic data to run hydrological models for several hundreds of catchments in various countries. In several recent studies, we have used these data sets for bucket-type modeling of a large number of catchments in different regions. In this presentation, I will discuss some of our main findings:Variability of results: Simulation results vary considerably between catchments, making it pertinent to apply a model to a large number of catchments for robust results.
Uncalibrated model performance: Simple bucket-type models can provide surprisingly good results for some catchments even when not calibrated. This needs to be considered when we assess model performances.
Prediction in ungauged catchments: It can be challenging to improve simulations for ungauged catchments by regionalization as it is not obvious how to choose the most suitable donor catchments. Thanks to data sets with a vast number of potential donor catchments, we found that almost perfect donor catchments seem to exist in most cases. However, the challenge remains to identify them.
Model structure: For some catchments, a simplified soil routine with only one free parameter (instead of three) outperformed the standard model version.
Value of data: Large samples of catchments allow us to evaluate the value of different data types: a limited number of streamflow gaugings and other data types, such as stream level, stream width or water level class data, can be informative for streamflow simulations.
Sea level projections for the German Coast
Authors: Jensen Corinna , Janssen Frank , Möller Jens , Kruschke Tim
Published: March 2024

Sea level rise is a certain consequence and one of the most important threats associated with climate change. It increases the risk of flooding of low-lying land at the German Coast.In cooperation of the “Network of Experts” of the German Federal Ministry for Digital and Transport and the DAS core service “climate and water”, we aim to provide high-quality projections of relative sea level change for the German coastal areas, both in terms of spatial data as well as time series for specific stations. Most of the drivers for sea level change must be considered on a continental or global scale. The main exception for this in northern Europe is land uplift as its impacts are regional and dependent on glacial isostatic adjustment as well as local processes. We therefore created a new set of sea level projections for the North Sea and Baltic Region. This dataset is based on the IPCC 6th Assessment Report (AR6) projections of absolute sea level change, which we combine with a new and high-resolution land elevation model over Fennoscandia (instead of the coarse land elevation model for this region used in the IPCC AR6). The data will eventually be published via the “DAS core service”. 
Climate Extremes and Systemic Risks for Sustainable Development Pathways – Artificial Intelligence for Risk Mitigation?
Authors: Reichstein Markus , Benson Vitus , Carvalhais Nuno , Frank Dorothea , Robin Claire
Published: March 2024

Climate change is increasingly leading to severe and frequent extreme events, ranging from forest fires to heatwaves, droughts, and floods. These events are likely not only intensifying as our climate continues to warm but also interlink across various environmental and social systems. For example, a heatwave can trigger forest fires, which in turn lead to air pollution impacting public health. Droughts can disrupt agricultural production, causing market fluctuations and exacerbating socio-economic inequalities, potentially leading to social unrest. Despite the growing systemic risks posed by these extreme climate events, they are often inadequately addressed in national strategies for achieving the United Nations Sustainable Development Goals (SDGs).The core challenge in tackling these risks stems from their roots in the dynamic boundary conditions of global warming, such as rising temperatures and altered precipitation patterns. Conventional risk models designed for assessing discrete, non-climate-related hazards or based on past climate are becoming increasingly invalid in this non-stationary scenario. In addition, process-based models are challenged by high-resolution complex-systems forecasting tasks. This is due to both epistemic limitations in understanding climate-ecosystem-society interactions and computational constraints. We discuss howArtificial Intelligence (AI) can serve as a complementary and effective tool in understanding, managing, and communicating these systemic risks, given its ability to process vast datasets and uncover patterns within complex systems. The vision is an AI enabled Early warning system of complex risk, operating on several time-scales (hours to decadal).
Distribution of clay minerals offshore eastern Taiwan: New evidence of volcanic material sources and transportation processes
Authors: Su Chih-Chieh , Lin Jheng-Kuan , Hsu Ta-Wei , Chen Yu-Huang , Hsu Sheng-Ting
Published: March 2024

Huatung Basin, Gagua Ridge, Yaeyama Ridge, and Ryukyu Forearc Area are the main terrain characteristics offshore eastern Taiwan. Several submarine canyons are distributed in the basins and play an important role in sediment transportation. In terms of geographical location, Taiwan and Ryukyu Islands are the main sources of terrestrial materials, while Luzon Island, upstream of Kuroshio, is also one of the potential sources. Tectonic, typhoon, and monsoon activities intensively affect the flux of terrestrial materials into the ocean, which leads to the variation of sedimentation rates from 0.35 cm/a in the nearshore area of Taiwan to 0.06 cm/a in the Huatung Basin. All are much higher than the West Philippine Basin (5-7 mm/ka). Based on the differences in terrestrial material composition among Taiwan, Ryukyu, and Luzon, the study of clay mineral composition has become a potential tracer for identifying the source of sediments offshore eastern Taiwan. The controversy lies in the high content of smectite in the Huatung Basin. It was speculated that the main provenances of smectite may from eastern Taiwan (Chimei Igneous Complex) and the Ryukyu Island Arc, and the canyon systems developed off the eastern Taiwan transport terrestrial sediments over 150 km and deposited in deep Huatung Basin through turbidity currents or debris flows (Lin, 2021); or the Kuroshio transport the Luzon Arc materials into this area (Nayak et al., 2021). However, both interpretations are challenged by new comprehensive data. During the NOR1-0038A cruise in 2022, fist-sized pumice (~6 cm) was collected from the surface of the box core at the HT01 site in the Huatung Basin. Based on the mineral composition of the pumice, it is speculated that it was the product of the eruption of the submarine volcano "Fukutoku-Okanoba" in August 2020, and was brought here by currents and winds. This incident also had an impact on Taiwan's coast, with large amounts of pumice deposited in Taiwan's ports and beaches. The discovery of the "Fukutoku-Okanoba" pumice in the deep sea is of great significance to the source of volcanic ash or volcanic glass in sediments off eastern Taiwan. In addition, during the "Hakuho Maru" expedition from Dec. 13 to 23, 2023, large amounts of granite samples were first time collected by bottom dredge on the northern part of the Gagua Ridge, which may also be an important source of smectite. With the development of marine geological surveys in deep waters off ​​eastern Taiwan, our understanding of various sedimentary processes and sediment source-to-sink processes offshore eastern Taiwan continued to expand.
Improving the precision of Pb-Pb ages of carbonate rocks by implementing stepwise dissolution techniques: A case study from the Lower Vindhyan Group, India
Authors: Nandi Ankita , Vadlamani Ravikant , Bera Melinda Kumar
Published: March 2024

Chemical composition heterogeneity in carbonate rocks ranging from the microscale to several meters preclude their direct age determination. Therefore, stepwise dissolution of several bulk rock samples or subsamples of an individual specimen can provide information on the primary composition of the carbonate material and refine the resulting Pb–Pb age. A millimetre-thick carbonate-rich (white) and shale-rich (black) layer from the Rohtas Formation, Lower Vindhyan Group, was divided into eight subsamples each and subjected to three leaching steps. The first leachate (L1) was discarded, and subsequent leachates, L2 and L3, were obtained after 24 hours of leaching in 0.6M HBr. A Pb-Pb isochron age of 1666±25 Ma (n=23, MSWD=13) is obtained by regressing L2 and L3 leachates from both layers. Since initial leachates (e.g., L2) contain epigenetically altered carbonate material, data points in the 207Pb/204Pb vs 206Pb/204Pb plot are well correlated but show a large scatter. In contrast, regressing only the L3 leachates of both layers yielded a Pb-Pb isochron age of 1644±49 Ma (n=12, MSWD=7), with a reduced scatter and comparable with earlier published work. Increasing the number of leaching steps minimizes the degree of scatter and significantly improves the precision of the obtained Pb-Pb age. Two subsamples from phosphoritic stromatolite-bearing carbonate rocks of the Tirohan Dolomite from the Jankikund river section, Lower Vindhyan Group, were subjected to seven leaching steps, of one hour each, in 0.5M HBr. The Pb isotopic composition of the carbonate material dissolved in five steps (L3 to L7) was regressed to yield an isochron age of 1579±16 Ma (n=10, MSWD=1.3). The Pb-Pb age of the Tirohan Dolomite Member obtained by multi-step leaching in this study is indistinguishable within error from an earlier reported age [1] of 1650±89 Ma (n=5, MSWD=89), moreover shows a better correlation of the 207Pb/204Pb vs 206Pb/204Pb data. All the analyses were performed in static mode on a Thermo-Fisher Neptune Plus MC-ICPMS. The instrumental mass fractionation was corrected using both thallium-spiking and sample-standard bracketing. Furthermore, a generalized power law correction was applied to the 204Pb-corrected ratios of unknown samples using the 205Tl/203Tl ratios of the bracketing NBS-981 standards. The two-stage mass bias corrected ratios were then normalized by the ratios of NBS-981 during each analytical session. The long-term isotopic ratios of NBS-981 standard (n=71) are 206Pb/204Pb= 16.9371±0.0026 (2σ), 207Pb/204Pb= 15.4906±0.0046 (2σ), 208Pb/204Pb= 36.7042±0.0113 (2σ). [1] Bengtson, S., Belivanova, V., Rasmussen, B., Whitehouse, M. (2009). The controversial “Cambrian” fossils of the Vindhyan are real but more than a billion years older. Proceedings of the National Academy of Sciences, 106(19), 7729-7734.
A comparative study of climbing dunes between Valles Marineris on Mars and the Yarlung Zangbo River Valley on Earth.
Authors: Zhang Zhi , Dong Zhibao , Li Chao
Published: March 2024

Aeolian processes and landforms, which dominated contemporary surface processes on Mars, provided critical information for further understanding of the Martian environment and evolutionary history. However, human beings cannot currently land on the Martian surface to explore this mysterious planet. Based on the idea of comparative planetology, this study tries to focus on analogy research between the climbing dunes of Valles Marineris (VM) on Mars and China’s Yarlung Zangbo River Valley (YZ) on Earth. Firstly, we analyzed 2003 climbing dunes from Valles Marineris on Mars and China’s Yarlung Zangbo River Valley on Earth, and identified barchan dunes, barchanoid dunes, dune networks and transverse dunes as the main morphology types of climbing dunes. Furthermore, as a basic form of climbing dunes comparative analysis, we measured dune spacing, defect density, crest length and orientation from remote images at VM on Mars and YZ on earth. In the meantime, as the topographic parameter of climbing dunes, the slope of dunes had been extracted from the DEM data of VM and YZ. The result shows that the crest length of the climbing dunes scale of VM is over seven times than YZ, and the height of dunes in VM is over 4.5 times than YZ. In VM and YZ, nearly 90% of the dunes are barchanoid dunes and dune networks. Above 60% numbers of dunes assemble on a slope of 8-15°.
 
Keywords: Aeolian landforms; Sand dune landforms; Climbing dunes
Use of Active-DTS (heat tracer experiment) and FVPDM (tracer experiment) for field quantification of groundwater fluxes
Authors: Brouyère Serge , Balzani Laura , Jamin Pierre , Varisano Luca , Simon Nataline
Published: March 2024

Understanding of transport processes is essential to identify the fate of contaminants in surface and subsurface water. Quantification of such transport processes requires a sound understanding and quantification of groundwater flow fields. Over the past decades, efforts have been made to develop and propose field methods that provide direct estimates of groundwater fluxes. The challenge is to propose field methods able to reflect the complexity of groundwater flow pathes in aquifer systems. In this context, we investigated the potential of two field methods to estimate groundwater fluxes in consolidated aquifers. Both FVPDM (Finite Volume Point Dilution Method) and Active-DTS (Distributed Temperature Sensing) measurements were conducted in a single piezometer in a fractured chalk aquifer. On the one hand, the FVPDM, a single-well tracer experiment, provided a measurement of the groundwater flow rate across the tested piezometer. On the other hand, the Active-DTS method was performed by deploying a Fiber-Optic (FO) cable outside the piezometer within the gravel filter. This method provided high-resolution and local groundwater flux estimates along the heated section. We relied on numerical simulations to assess the distortion of the groundwater flow field induced by the presence of the well. The groundwater flux is maximum within the well screen, where the FVPDM test was conducted. In the vicinity of the well, where the heated FO cable was installed, the groundwater flow is lower, and the flow pattern consists of converging and diverging flow lines. Thus, the position of the heated FO cable related to the flow direction is critical and can have a significant impact on the estimation of the groundwater flux. Regardless, we demonstrate that deploying the FO cable within the gravel pack is a novel and efficient approach, which opens up interesting perspectives for the use of Active-DTS measurements in consolidated aquifers to estimate vertical heterogeneities.
Onset of compressive exhumation of the northern Santa Bárbara System (NW Argentina). Tectonic implications from low-T thermochronology
Authors: Garcia Victor Hugo , Galetto Antonella , Sobel Edward R. , Payrola Patricio , Montero Carolina , Elías Leonardo , Arnous Ahmad , Glodny Johannes , Hongn Fernando , Strecker Manfred R.
Published: March 2024

The Santa Bárbara System (SBS), located at the Central Andes of northwestern Argentina, is a thick-skinned fold-and-thrust belt (FTB) that represents the outermost portion of the orogenic wedge and the western boundary of the undeformed Chaco-Paraná foreland basin. The present-day structural architecture of the SBS is mainly governed by the reactivation of basement anisotropies and the inversion of Cretaceous normal faults imprinting an overall vergence towards the west. Some of the major faults show evidence of active tectonics in the landscape, which also correlates with instrumental seismicity and destructive earthquakes recorded.
Studies based on seismic interpretation of growth strata in synorogenic deposits have shown that the basement ranges of the southern SBS began to be uplifted during the late Miocene, although the magnitude of exhumation has not yet been quantitatively established. On the other hand, thermochronological analyses of basement samples from the neighboring Eastern Cordillera (EC) have highlighted the relevance of a late Miocene (ca. 10 Ma) exhumation event that propagated the orogenic front into the Mojotoro range, west of the northern SBS.
In this contribution, we present the first (U-Th-Sm)/He cooling ages from Paleozoic rocks of the northern SBS and from the Neoproterozoic basement of the Reyes range, in the EC. The integration of these data with previously published cooling ages allows to conclude that the late Miocene compressional event reached the northern SBS, driving the exhumation of the basement-cored ranges by 7-8 Ma, much earlier than previous estimations. In addition, the Reyes range sample yielded a younger cooling age (ca. 4 Ma) which agrees well with the model of hinterland reactivation of faults due to the recovery of a sub-critical orogenic wedge, as proposed by previous publications.
Based on the available structural reconstructions, an average exhumation rate of ca. 0.7 mm/a can be estimated for the western frontal thrusts of the northern SBS. This value agrees with the late Pleistocene-Holocene rates obtained for neotectonic morphostructures of the Lerma Valley, the easternmost intermontane basin of the EC, suggesting the continuation of a similar deformation pattern throughout the Quaternary for this portion of the Andean back-arc. Additionally, our results shed light on the tectonic evolution style of thick-skinned FTB´s and broken foreland basins.
Exploring data-driven emulators for snow on sea ice 
Authors: Prasad Ayush , Merkouriadi Ioanna , Nummelin Aleksi
Published: March 2024

Snow is a crucial element of the sea ice system, impacting various environmental and climatic processes. SnowModel is a numerical model that is developed to simulate the evolution of snow depth and density, blowing-snow redistribution and sublimation, snow grain size, and thermal conductivity, in a spatially distributed, multi-layer snowpack framework. However, SnowModel faces challenges with slow processing speeds and the need for high computational resources. To address these common issues in high-resolution numerical modeling, data-driven emulators are often used. They aim to replicate the output of complex numerical models like SnowModel but with greater efficiency. However, these emulators often face their own set of problems, primarily a lack of generalizability and inconsistency with physical laws. A significant issue related to this is the phenomenon of concept drift, which may arise when an emulator is used in a region or under conditions that differ from its training environment. For instance, an emulator trained on data from one Arctic region might not yield accurate results if applied in another region with distinct snow properties or climatic conditions. In our study, we address these challenges with a physics-guided approach in developing our emulator. By integrating physical laws that govern changes in snow density due to compaction, we aim to create an emulator that is efficient while also adhering to essential physical principles. We evaluated this approach by comparing four machine learning models: Long Short-Term Memory (LSTM), Physics-Guided LSTM, Gradient Boosting Machines, and Random Forest, across five distinct Arctic regions. Our evaluations indicate that all models achieved high accuracy, with the Physics-Guided LSTM model demonstrating the most promising results in terms of accuracy and generalizability. This approach offers a computationally faster way to emulate the SnowModel with high fidelity. 
TRANSGEO - Transforming abandoned wells for geothermal energy production
Authors: Hofmann Hannes , Friddell Julie , Sass Ingo , Höding Thomas , Sieron Katrin , Svetina Max , Hölzel Monika , Philipp Robert , Márton György , Borkovits Balázs , Bődi Klára , Višnjić Alen , Kurevija Tomislav , Vogrinčič Bojan
Published: March 2024

TRANSGEO is a regional development project that aims to explore the potential for producing sustainable geothermal energy from abandoned oil and gas wells in central Europe.  Composed of 11 partner organizations and 10 associated partners in 5 countries, TRANSGEO is developing a Transnational Strategy and Action Plan to address this technical and economic opportunity.  Our primary objective is to support rural communities and industries in the energy transition by providing tools and information that highlight sustainable redevelopment priorities and opportunities.To reach this objective and promote the switch from fossil fuels to green energy, TRANSGEO is developing reuse procedures for five different geothermal technologies and validating them via numerical modelling, to assess their performance in repurposing existing hydrocarbon infrastructure and determine the optimal reuse conditions and configurations.  The five geothermal technologies are Aquifer Thermal Energy Storage, Borehole Thermal Energy Storage, Deep Borehole Heat Exchangers, Enhanced Geothermal Systems, and Hydrothermal Energy production.  The modelling studies focus on reference sites in our study areas, the North German Basin, the South German Molasse Basin, the Vienna Basin, and the Pannonian Basin.  Comparison of varying wellbore and reservoir parameters in the numerical modelling studies will provide input to a new online well assessment tool which will be available publicly to determine well suitability and guide planning for future reuse projects.  The online tool will be informed by a database of abandoned wells in Austria, Croatia, Germany, Hungary, and Slovenia and will include local reference data, such as geology, topography, heat demand, and utilities.  This will facilitate well reuse by matching candidate wells with local energy demand and heating networks.  Additional work on socio-economic and policy analyses will provide financial and liability information for the 5 different geothermal technologies, across the project countries.  Finally, the partnership will propose a legal policy and incentive framework to facilitate and expand reuse of abandoned wells for geothermal energy production and storage across central Europe.TRANSGEO is co-funded by the European Commission’s Interreg CENTRAL EUROPE programme.
Identifying irrigated areas in the Rhine basin using land surface temperature and hydrological modelling
Authors: Purnamasari Devi , ter Maat Judith , Teuling Adriaan , Weerts Albrecht
Published: March 2024

In recent years, the Rhine has experienced summer drought which led to extremely low water availability throughout the basin. Additionally, combination of high temperature and low precipitation may increase irrigation demand, putting even more pressure on water availability. Identifying where irrigation occurs and how it evolves over time offers improved insight water use for sustainable water resources planning and management. However, high-resolution maps of irrigated areas for basin-scale studies on water use are often lacking. Here, as part of the HorizonEurope project STARS4Water, we aim to develop a methodology for identifying irrigated areas in the Rhine basin at a 1 km resolution for the period of 2010-2019. This involves utilizing a combination of the hydrological model wflow_sbm to produce land surface temperature (LSTsim) and thermal observations data (LSTobs) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. To provide consistent annual irrigation maps, we employed random forest classification model to further identify irrigated areas from the LST difference between LSTsim and LSTobs. In the absence of ground information data, the irrigated maps are evaluated against national agricultural statistics and compared with existing developed irrigated maps. The results can be used to comprehend the interannual variability in the extent and location of irrigated croplands in the Rhine basin and are a start to assess and model agricultural water use in the Rhine basin. 
Revealing mantle heterogeneity in a cold intra-transform spreading segment (7-8°N at Mid Atlantic Ridge)
Authors: Sani Camilla , Sanfilippo Alessio , Skolotnev Sergey , Ligi Marco , Genske Felix , Stracke Andreas
Published: March 2024

The Doldrums transform system (TS), located in the Equatorial Mid Atlantic Ridge (MAR) at 7-8°N, is a 110 km-wide multi-fault shear zone, with five active transform faults separated by four short intra-transform ridge segments (ITRs). The medial ITRs are substantially deeper than the peripheral rift segments, which indicate differences in the thermal conditions of the sub-ridge mantle. New chemical and radiogenic isotope data from on-axis lavas erupted across the entire transform domain reveal that the basalts from the shortest and deepest ITRs are enriched comparatively in alkalis (Na2O+K2O= 4.3 wt%; Na8 up to 3.7) and light rare earth elements (La/Sm)N = 0.86 -0.97), likely suggesting the presence of an extremely cold mantle region characterised by low degrees of partial melting. The enriched incompatible element compositions, however, are coupled with the lowest Sr and Pb isotopes in the Equatorial Atlantic magmatism (i.e., 87Sr/86Sr ~ 0.70237 and 206Pb/204Pb ~ 18) and relatively high Nd and Hf isotope ratios (143Nd/144Nd = 0.51315-0.51325; 177Hf/176Hf = 0.2832-0.28325), which indicates that incompatible element enriched components are less abundant in the mantle source of the central ITRs. Hence we infer that the mantle under the central ITRs has been melted at the MAR axis before being transported laterally into the central ITR domain during the formation of the Doldrums transform system. This mantle portion melted a second time, and to a low extent, during the opening of the cold ITR, revealing its depleted geochemical character. Therefore, MORB from intra-transform ridge segments provide a rare opportunity to constrain the isotopic composition of the depleted peridotitic mantle, a ubiquitous, but otherwise often concealed component of Earth’s mantle.
From atmospheric water isotopes measurement to firn core interpretation in coastal sites: A method for isotope-enabled atmospheric models in East Antarctica
Authors: Leroy-Dos Santos Christophe , Fourré Elise , Agosta Cécile , Casado Mathieu , Cauquoin Alexandre , Werner Martin , Alexander Simon , Lewis Marshall , Favier Vincent , Vance Tessa , Harvie Derryn , Cattani Olivier , Minster Benedicte , Prié Frédéric , Jossoud Olivier , Petit Leila , Landais Amaëlle
Published: March 2024

In a context of global warming, it is key to estimate the evolution of the atmospheric hydrological cycle and temperature in the polar regions. Since records are only available from satellite data for the last 40 years, one of the best ways to access longer records is to use climate proxies in firn cores. The water isotopic composition of firn cores is widely used to reconstruct past temperature variations. However, both temperature and atmospheric water cycle (origin of the precipitation, deposition and post-deposition effects) influence the isotopic composition of snow. We present a 2-year long time series of vapor and precipitation isotopic composition measurement at Dumont D’Urville (DDU), a coastal station in Adélie Land. This unique data set is first used to study the link between hydrological cycle and weather regimes at DDU. It is found that both continental and oceanic air masses impact the signal. Then, this record is used to evaluate the Global Climate Model ECHAM6-wiso equipped with water stable isotopes which is able to reproduce the observed isotopic signal. This result permits further use of ECHAM6-wiso to interpret water isotopic profiles on short firn cores. Using this methodology, we evaluate ECHAM6-wiso atmospheric outputs at two other East Antarctic coastal sites: Davis  and Neumayer stations.
Insights into cloud biases over high-latitude oceans from a cloud-controlling factor framework
Authors: Blanco Joaquin , Caballero Rodrigo , Sherwood Steven , Alexander Lisa
Published: March 2024

A long-standing and pervasive problem within the modelling community is the proper representation of cloud albedo over the Southern Hemisphere (SH) oceanic region. Errors persist despite the extensive evidence that these are related to the unique microphysical characteristics of the austral clouds. In this study we investigate additional causes of cloud albedo biases over the 50˚–65˚ oceanic band using CMIP6 simulations and a cloud-controlling factor (CCF) approach on daily timescales. We gain further insight by replicating our method over the equivalent oceanic region in the Northern Hemisphere (NH).Cloud albedo, computed from upwelling and downwelling shortwave radiation at surface and top of the atmosphere, is averaged into bins of vertical velocity, surface wind, and sea-surface temperature. The performance of fifteen models in both atmospheric-only and ocean-coupled configurations is evaluated against CERES satellite retrievals in combination with ERA5 reanalysis for the 2000–2014 period.When averaging cloud albedo by vertical velocity bins, we find that shallow boundary-layer (deep convective) clouds are consistently underpredicted (overpredicted) over the high-latitude oceans of the SH. We repeat the method for the 50˚–65˚ band in the North Atlantic and Pacific oceans and find that similar compensating errors exist.Another important result is that the SH cloud biases occur for sea-surface temperatures below 4°C. We show that a connection exists between this empirical finding and the biases as determined from microphysical effects, i.e.: a deficit of cloud albedo is due to models producing glaciated rather than supercooled liquid water clouds. Our CCF method allow us to see that in such cases, models tend to simulate NH clouds for the SH.We also find that the positive sign of the cloud albedo hemispheric asymmetry (SH-NH difference over the 50°–65° band) is consistently predicted by nearly all models, many of which also predict a similar magnitude to observations. However, this is a consequence of compensating errors as individually most models tend to either overpredict or underpredict cloud albedo in both hemispheres.
Halogen activation in volcanic plumes: Studies at Mt Etna (Italy) 2022 and 2023
Authors: Geil Bastien , Bobrowski Nicole , Karbach Niklas , Kuhn Jonas , Nies Alexander , Roberts Tjarda , Hoor Peter , Hoffmann Thorsten
Published: March 2024

Halogens in volcanic plumes are important for both volcanic and environmental research. For example, changes in the composition of the volcanic plume can be an indication of changes in the activity of the volcano. Volcanic emissions consist mainly of emitted H2O, CO2 and SO2 and are rapidly mixed with surrounding background atmosphere. Additionally, HF, HCl and HBr are also significant constituents of volcanic emissions.The halogens are of particular interest for atmospheric chemistry. They are oxidized by mixing with the atmosphere. In this context, BrO should be mentioned as it is one of the oxidation products and like SO2, can be measured spectroscopically using remote sensing technique and therefore making it nearly ideal for surveillance of volcanoes. However only, if the oxidation process is understood, the composition of the volcanic plume at the emission site can be traced and thus possibly the changes in volcanic activity can be understood.Furthermore, these results are essential for the improvement of the atmospheric impact of volcanic halogens.Currently, several methods are used to detect the various halogen compounds. Remote sensing methods exist for only a few (in general BrO, OClO, HCl, HF). We use in-situ sampling methods such as cis-Stilbene coated syringe filter and aqueous alkaline traps to collect reactive and total halogen species, respectively.In this presentation, we will show quantitative results of samples taken in July 2022, June 2023 and in August 2023 for Cl2, Br2, BrCl, total bromine and sulfur from measurements of the Bocca Nuova and South East crater plume, Mt. Etna, Italy using UAV based in situ measurements in various distances to those emission sources. The results confirm the increase of reactive bromine and show for the first time the differentiation into Cl2, Br2, BrCl and total bromine and sulfur. Also BrO/SO2 values analyzed from DOAS measurements taken further downwind during the campaign will be presented.
Phenology controls on CO2 exchange in a northern peatland: insights from a decade-long record of phenocam imagery and eddy-covariance data
Authors: Simpson Gillian , Järveoja Järvi , Nilsson Mats , Peichl Matthias
Published: March 2024

Northern peatlands are recognised as important long-term carbon sinks. However, measurements from a number of peatland sites reveal a large amount of interannual variability in their net carbon dioxide (CO2) balance. Differences in both weather conditions and plant phenology (i.e. the seasonal development of the vegetation canopy) between years are thought to be key here. Timing of the growing season (i.e. start, end, length) regulates the period over which vegetation can actively photosynthesise. Hence, a longer growing season is often related to increased seasonal CO2 uptake for example. At the same time, meteorological conditions (e.g. air temperature, water-table depth) affect not only plant physiology, but also its phenological cycle. Our current understanding of the complex interplay between these two main drivers of peatland carbon dynamics has been limited by a lack of long-term phenology studies. This work explores a unique, decade-long record of phenocam and eddy-covariance data from Degerö Stormyr, a northern Swedish peatland. We used structural equation modelling (SEM) to identify the pathways regulating CO2 uptake, and found that phenology plays an important ‘mediator’ role over the growing season. Our analysis of the interannual and seasonal variability in the drivers of CO2 uptake further suggest that increases in vegetation greenness are linked to increased CO2 uptake over the growing season. These findings provide valuable insight on the controls of peatland carbon dynamics, and its feedbacks with future climate change.