bluuebunny/crossref_metadata_2025 huggingface dataset:
Project PORO-CLIM initial results: Towards a new oceanic crustal record of magma productivity throughout initiation of the North Atlantic Igneous Province 
Authors: Knight Hazel , Jones Stephen M , Hopper John R , O'Reilly Brian M , Funck Thomas
Published: March 2022

In May 2021 project PORO-CLIM acquired a new geophysical dataset across the little studied Porcupine and Rockall Plateau passive margins in the Northeastern Atlantic. The project aims to study the initiation of the North Atlantic Igneous Province (NAIP) and test its relationship with the Palaeocene-Eocene Thermal Maximum (PETM) global climate change event. Profile 1, a 400 km long deep seismic (MCS and OBS) profile, contains a continuous latest-Cretaceous to early-Eocene oceanic crustal thickness record that spans the entire emplacement of the NAIP. Oceanic crustal thickness can be directly interpreted as a record of magma productivity and hence mantle temperature. As such Profile 1 encodes the first continuous, sub-million year record of the entire waxing and waning cycle of mantle temperature during the initiation of any of the world’s Large Igneous Provinces.

Thermogenic methane produced by shallow igneous sills within the NAIP sill province and released to the atmosphere through hydrothermal vent systems, together with the carbon dioxide released from the magma itself, are the most likely carbon sources for the PETM [1]. Profile 1 is the first whole crustal seismic record across Eriador Ridge, thought to be the thick oceanic crustal trace of the pulse of anomalously hot mantle which drove the pulse of melting which led to NAIP sill province emplacement. Thus the magma productivity record derived from Profile 1 will ultimately help constrain the rate of NAIP thermogenic carbon emissions, further testing the link between NAIP sills and the PETM. This presentation will outline the initial findings from seismic data analysis, including a preliminary magma production record spanning NAIP initiation and the relationship between magma productivity and the PETM. Initial analysis of relative changes in crustal thickness across the record suggest that long-term (>5 My) magma productivity increased from late Cretaceous to early Eocene time, whilst short term (<5 My) magma productivity became more pulsed. The new dataset also shows Eriador Ridge contains a previously unknown double peak in magma productivity. These peaks may potentially be the result of two distinct pulses of anomalously hot mantle, separated by c. 1 Myr, which could imply multiple bursts of gas release from the NAIP around the Palaeocene-Eocene boundary.

[1] Jones, S.M., Hoggett, M., Greene, S.E. and Jones, T.D. Large Igneous Province thermogenic greenhouse gas flux could have initiated Paleocene-Eocene Thermal Maximum climate change. Nat. Commun. 10, 5547 (2019).
Semi-automatic production of highly detailed cave maps from LiDAR point clouds
Authors: Nováková Michaela , Šupinský Jozef , Kaňuk Ján , Gallay Michal
Published: March 2022

Remote sensing technology based on laser scanning (LiDAR) has found a wide range of applications in cave mapping for a high degree of accuracy, level of detail, and time efficiency of this method. Besides the multidisciplinary research, the acquired data representing the cave morphology in a form of a dense point cloud became an essential part of the exploration for understanding the cave speleogenesis alongside capturing the current state that is of great importance in natural and cultural heritage documentation. Traditional cave cartography can benefit from using the LiDAR point clouds by a highly detailed 3D cave model enabling the creation of contours, shaded relief, or geomorphometric parameters, and a practically unlimited number of cross-sections. Compared to the passive remote sensing methods, such as photogrammetry, limited by the light conditions and cave dimensions, laser scanning is an active light-independent method that records additional attributes for each captured point in addition to its 3D coordinates. The recorded intensity of the backscattered laser pulse is very applicable for mapping purposes as it reveals spectral properties of the surface material bringing new aspects not only for the point cloud visualization but also for material differentiation, identification, and spatial localization of the cave paintings. The presented study introduces innovation in the methodology of creating a high-detail cave map from the acquired LiDAR data by combining derived cave floor model and semi-automatic procedure for identification of surface type based on the geomorphometric analysis and recorded intensity. The main benefit of the proposed approach is in the reduction of the author´s subjectivity and cave geometry generalization. By further automatization of this process, maps for large cave systems can be produced in a high level of detail.
Impact of coupling frequency on warm and cold cavities in coupled Antarctic ice-sheet model simulations
Authors: Zipf Lars , Pelletier Charles , Haubner Konstanze , Pattyn Frank
Published: March 2022

Sub-shelf melting is one of the dominant drivers of Antarctica's ice sheet mass loss. Various sub-shelf melt rate parameterizations exist for standalone ice models, but they lack the capability to capture complex ocean circulation within ice shelf cavities. To overcome drawbacks of standalone models and to improve melt parameterizations, high resolution coupling of ice sheet and ocean models are capable of hindcasting past decennia and be compared to observations.

Here, we present results of a hindcast (1985-2018) of the new circumpolar coupled Southern Ocean – Antarctic ice sheet configuration, developed within the framework of the PARAMOUR project. The configuration is based on the ocean and sea ice model NEMO3.6-LIM3 and the ice sheet model f.ETISh v1.7. The coupling routine facilitates exchange of monthly sub-shelf melt rates (from ocean to ice model) and evolving ice shelf cavity geometry (from ice to ocean model).

For a selection of warm and cold cavities, we investigate the impact of the coupling frequency (more precisely, the frequency of updating the ice shelf cavity geometry within the ocean model) and the coupling itself on the sub-shelf melt rates and its feedback on the ice dynamics. 
We further compare the sub-shelf melt rates and the response of the ice sheet with observations and other studies.
The TWIN - Hemera stratospheric balloon flight: sulfur, halogens and tracers in the stratosphere
Authors: Popa Maria Elena , Engel Andreas , Chen Huilin , Ghysels-Dubois Mélanie , Laube Johannes C , Amarouche Nadir , van Heuven Steven , Baartman Sophie , Schuck Tanja , Wagenhäuser Thomas , Zanchetta Alessandro , Durry Georges , Keber Timo , Richter Anneliese , Sitnikow Andreas , Frerot Fabien , Samake Jean Christophe
Published: March 2022

The TWIN - Hemera stratospheric balloon flight took place on 12 - 13-Aug-2021 from the Esrange Space Center near Kiruna, Sweden (67°N).The project was supported by Hemera (www.hemera-h2020.eu) via the first call of proposals, and the flight was managed by the CNES (Centre national d'Etudes Spatiales) and SSC (Swedish Space Corporation). The scientific payload was developed in collaboration by several institutions from the Netherlands, Germany and France.

The main objectives were: (1) to characterize the vertical structure of COS mole fraction and isotopic composition; (2) to characterize the CFCs, other ozone depleting substances and climate relevant trace gases in the present atmosphere, linked to their change over the past decade; and (3) to compare and evaluate several instruments and sampling techniques.

The payload included several AirCores (U. Frankfurt, CIO and FZJ), two Pico-SDLA mid-infrared in-situ diode laser spectrometers (GSMA/DT-INSU), and devices for taking large whole air samples of stratospheric air for subsequent laboratory measurements: the BONBON whole-air cryosampler (U. Frankfurt) and LISA (CIO). IMAU is involved for the analysis of isotopic composition and mole fractions of samplers from the cryo-sampler. This approach allows obtaining a comprehensive dataset covering a range of spatial resolutions: from the multitude of gas species to be measured in the high-volume samples, to the subset of gases at higher vertical resolution from AirCores, and finally to the continuous in-situ CO2 and CH4 data from tunable diode laser spectroscopy. We expect this dataset to lead to novel and important knowledge on the trace gases in the stratosphere.

In this presentation we will describe the overall setup of the scientific payload, the flight characteristics, and we will give an overview of the already performed and planned measurements.
Historical buttressing effects on present-day Dotson and Crosson Ice Shelf dynamics
Authors: Child Sarah F. , Scambos Ted , Chu Winnie , Stewart Ella , Alley Karen
Published: March 2022

For almost three decades, the Dotson and Crosson Ice Shelves have withstood various degrees of velocity increases, basal melt, weakening shear margins, and grounding line retreat. The two ice shelves, located along the Amundsen Sea Embayment, are fed primarily by Kohler, Smith, and Pope Glaciers. The ice shelves were once thought to be separated by a landmass connecting Bear Island to the mainland, but there is no evidence from 75 years of available data supporting this partition. Recent research shows that the changes in dynamics undergone by both ice shelves and their outlet glaciers are due largely to basal melt driven by warm circumpolar deep water (CDW); however, the scope of those changes varies between the two sectors with the Crosson Ice Shelf experiencing the more extreme transformation. Observations from trimetrogon aerial imagery (late-1940s) and Landsat Thematic Mapper data (mid-1980s) reveal the northern edge of the Crosson Ice Shelf terminating at Holt Glacier and its southeastern edge buttressing against Haynes Glacier. Studies show that in the mid-1980s, a decrease in sea ice concentrations led to the migration of the detached Thwaites Ice Tongue which, with fast ice, aided in containing fragments of Thwaites Glaciers—around this time the retreat of Haynes Glacier’s ice tongue also began. We hypothesize it is this decrease in buttressing from ~35 years ago that began a continuous trend (still observed today) in ice shelf thinning, initiation of rifts, and outlet glacier speed increases and grounding line retreats. In contrast, the Dotson Ice Shelf is flanked by Bear Island and Martin Peninsula and has undergone less dramatic alterations in dynamics than the Crosson Ice Shelf. We quantify the impact of buttressing on the two connected ice shelves with the following analyses: extended temporal scale of outlet glacier hypsometry from 1960-the present; detailed 16-year study of grounding line migrations and hydrostatic equilibrium boundaries using CReSIS MCoRDS/2 level one data; estimated shear stresses from multi-year velocities; modeled back stresses acting on both ice shelves. Results of this study will help to improve modeling ocean-ice sheet interactions and better constrain CDW impacts.
Exploring new experimental possibilities for the investigation of nonlinear mesoscopic elasticity
Authors: Asnar Manuel , Bonnelye Audrey , Sens-Schönfelder Christoph , Dresen Georg
Published: March 2022

In rocks, concrete, and a variety of other heterogeneous materials commonly grouped in the “nonlinear mesoscopic elasticity” class, dynamic excitation leads to a fast softening of the material, followed by a slower recovery process where the material recovers part of its initial stiffness as a logarithmic function of time. This requires us to exit the convenient framework of time independent elastic properties of the solid Earth.

These phenomena can be observed during seismic events in affected infrastructure as well as in the subsurface. Since the transient material changes are not restricted to elastic parameters, but also affect hydraulic and electric parameters as well as material strength, as documented for instance by long lasting changes of landslide rates, it is of major interest to characterize the softening and recovery phases. This may help us gain more insight in hazard prediction from both a geological and engineering perspective.

However, the underlying physics of nonlinear mesoscopic elasticity are not agreed upon, as there is a lack of experiments that would allow us to discriminate between the existing models. We aim to contribute to that goal.

Our experiment is made on an MTS815 testing system, with a 100x50mm sample of dry Bentheim sandstone. The sample is subjected to a series of load and hold cycles in the elastic domain, with strains ranging between 1e-5 and 1e-6, while undergoing a progressive increase in confining pressure.

Active acoustic measurements during those loading cycles, with an array of 15 acoustic sensors, allow us to determine wavespeed changes over the course of the experiment to observe the dynamic softening as well as the recovery process in the sample.

In this preliminary experiment, we investigate the capabilities of the testing machine in terms of signal quality, signal stability and lapse time dependent decorrelation of coda waves. In a second phase, we will vary confining pressure, pore pressure and temperature in order to study the influence on the softening and recovery phases.
A network-based assessment of fine sediment connectivity in an agricultural catchment in Austria
Authors: Perez John Edward , Poeppl Ronald E.
Published: March 2022

The measurement of soil erosion has been a major priority of scientific research and government programs since the beginning of the 20th century due to its increasing significance as an environmental challenge.  Identification of sediment source areas, sinks, and the pattern of geomorphic coupling between different zones along its pathways are essential for an effective and holistic catchment management. In this context, soil erosion and associated fine sediment transfer through landscapes can be assessed using the concept of connectivity. Among different approaches applied in sediment connectivity investigations, a major advance in recent years has been the adoption of network analyses. This study presents an attempt to use numerical modeling coupled with graph theory analysis as an approach to quantify sediment connectivity on the catchment scale, as well as to identify key locations and pathways of sediment (dis-)connectivity in a medium-sized agricultural system in Austria for different rainfall events. Runoff and soil losses are simulated using the soil erosion model OpenLISEM and then translated into a graph using the network analysis package igraph in Python. Structural properties of the graph are then assessed using the same package. First results show notable sediment concentrations in the middle reaches of the trunk channel, similar to patterns of sediment input hotspots in earlier studies in the catchment. This corresponds to erosional areas that are well connected to the stream network via different kinds of overland flow pathways. Insights from graph-based connectivity metrics can be valuable in designing targeted interventions for catchment management based on identified hotspots of soil erosion and the associated off-site effects brought about by connectivity patterns.
Geothermal exploitation in the inverted part of the Lower Saxony Basin: A case study from the Minden area
Authors: Knaub Olga , Jüstel Alexander , Bussmann Gregor , Wellmann Florian , Kukla Peter
Published: March 2022

Issues of sustainability and climate change are among the driving forces of current research aiming to remedy the grave consequences of greenhouse gas emissions. The consequent system change into the usage of regenerative energy sources through the replacing of fossil fuels represents the most promising solution. This structural change poses large challenges not only for metropolitan areas, but also for smaller towns, which intend to increasingly utilize renewable energies. One such example is the city of Minden in the northernmost part of the state of North Rhine-Westphalia, which serves as case study for this project. The city is geologically situated in the inverted part of the Lower Saxony Basin. This represents a sub-basin in the western part of the North German Basin, which is one of three economically viable regions for geothermal energy production in Germany. The investigation of the feasibility of generating electricity and heat through the exploitation of the deep geothermal reservoirs was driven based on the requirements of a company situated in Minden, which exclusively uses fossil fuels for their industrial processes. In order to generate steam, the production requires high temperatures from the subsurface (> 140°C).

The evaluation of geothermal projects conducted in the North German Basin, regional studies and interpretation of 2D seismic data confirmed the existence of the so-called Wiehengebirge Syncline with outcropping Jurassic rocks in the mountain range to the south of Minden. The compilation of all available data and models highlighted Mesozoic layers of the middle Bunter sandstone (Volpriehausen-Solling formations, 4.0-4.5 km), the Keuper (Stuttgart formation, 3.0-3.3 km) and the Dogger (Bathonium-Callovium formations, 1.8-2.4 km) as potential target horizons within the syncline. Moderate to good hydraulic properties are anticipated for the siliciclastic targets. Furthermore, the hydraulic productiveness of a fault mapped in the immediate vicinity of the investigation site was determined through dynamic reservoir simulations.

Moreover, drilling data provided by the hydrocarbon industry from the gas fields to the north of the city (e.g. Uchte) were used to set up a thermo-hydraulic model in order to determine temperatures and flow rates. These should ultimately specify the most promising formations within the afore mentioned Mesozoic units for further geothermal exploration and developments.

Summarizing, first results of this study have confirmed the deep geothermal energy potential of the western part of the North German Basin and the city area of Minden.
Assessing of future drought in the Canary Island
Authors: Hernandez-Barrera Sara , Carrillo Judith , González Albano , Pérez Juan Carlos , Expósito Francisco Javier , Díaz Juan Pedro , Rodríguez Jesús F.
Published: March 2022

Drought is one of the main natural phenomenon that has a significant impact on agricultural, economic and environmental. In the Canary Islands, drought events are of great importance due to overexploitation of water resources.  This study analyses climate change projections in terms of frequency, duration, and severity of future drought with the Weather Research and Forecasting (WRF) model driven by some Coupled Models Intercomparison Project phase 5 (CMIP5) simulations, for three periods, until the end of the century, and for two Representative Concentration Pathways (RCP) scenarios (RCP4.5 and RCP8.5). Projected changes are obtained using two well-established drought indices; the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) at two different time scales (3 and 12 months). Extreme drought (wet) events are considered when SPI is lower (higher) than -2 (2). The results show an increase of extreme drought events by the end of this century for both emission scenarios, with respect to the reference period (1980-2009) and an uneven impact of altitude in drought. The threshold of extreme dry (wet) decreases from 14.2 to 11.1 mm/year (367.4 to 290.0 mm/year) at the altitude interval of 0-400 m, and from 11.7 to 0.5 mm/year (1546.2 to 1074.2 mm/year) at elevations higher than 2100 m.

 
Error-reducing Structure-from-Motion derived Digital Elevation Models in data-scarce environments
Authors: Bakker Dirk , Phùng Phuoc , van den Homberg Marc , Veraverbeke Sander , Couasnon Anaïs
Published: March 2022

High-accuracy Digital Elevation Models (DEMs) improve the quality of flood risk assessments and many other environmental applications, yet these products are often unavailable in developing countries due to high survey costs. Structure-from-Motion (SfM) photogrammetry combined with Unmanned Aerial Vehicles (UAVs) has been proven as an effective and low-cost technique that enables a wide audience to construct local-scale DEMs. However, the deviation from strict survey designs and guidelines regarding the number and distribution of Ground Control Points (GCPs) can result in linear and doming errors. Two surveys that suffer from these errors have been supplied for error-reduction, but both areas did not have an available high-accuracy DEM or could afford an additional differential Global Navigation Satellite System (dGNSS) ground survey to extract control points from to use in relative georeferencing approach. Little attention has been given to error-reduction using global open-access elevation data, such as: The TerraSAR-X add-on for Digital Elevation Measurements (TanDEM-X) 90; the Ice, Cloud and land Elevation Satellite-2 (ICESat-2); and Hydroweb.

The aim of this study was to improve and validate the two DEMs using control point extraction from the above data and analyze the validation results to determine the impact on error-reduction using regression analyses between the vertical error and distance from nearest control point. The outcomes shows that the ICESat-2 and Hydroweb can support surveys in absence of dGNSS GCPs with similar impact but cannot replace the necessity of dGNSS measurements in georeferencing and validation. These findings suggests that survey guidelines can be maintained with global open-access elevation data, but the effectiveness depends on both the number, distribution and estimated accuracy. Doming errors can be prevented by correct camera lens calibration, which depends on stable lens conditions or a stratified distribution of high-accuracy reference data. The validation of the SfM DEM in data-scarce areas proves difficult due to the lack of an independent validation dataset, but the Copernicus GLO-30 can give a quantification and show the spatial variability of the error. This study highlights the increasing accuracy of global open-access elevation data and shows that these databases allow the user to easily acquire more and independent data for georeferencing and validation, but the RSME is unable to be accurately reduced to sub-meter.
Determining Demagnetization Energy and Internal Stress in Natural Magnetite Bearing Samples
Authors: Béguin Annemarieke , Fabian Karl , Church Nathan , McEnroe Suzanne
Published: March 2022

The stability and acquisition of remanent magnetization in Earth and planetary rocks is controlled by the magnetization state of magnetic particles. Magnetic properties are often characterized by magnetic grain size. Besides grain size, also stress, magnetostatic interactions, and grain shape influence and modify magnetic stability. Moreover, internal stress in magnetite may substantially affect remanence acquisition and might be responsible for enhanced remanence for which the processes are often still enigmatic.

To better understand the impact of internal stress on the efficiency of remanence acquisition, their contribution needs to be separated from the magnetostatic and demagnetizing energy contributions. Direct observations of the influences of magnetocrystalline and stress anisotropy on the magnetic behavior of magnetite are obscured by the large demagnetizing energy. A new temperature-dependent hysteresis measurement and evaluation procedure was developed by Béguin & Fabian, (2021), which allows the determination and separation of demagnetizing energy and internal stress. The validity of the method was demonstrated for a suite of synthetic magnetite samples under different stress conditions.

Here we present the first results of applying the new scaled reversible work (SRW) method to a set of natural magnetite bearing samples. We used samples with homogeneous and heterogeneous microstructures and end-member stress-free magnetite samples. The magnetic behavior as function of temperature is less ideal for the natural samples than for the previously studied synthetic magnetite samples, for example, the Curie temperatures are less distinct. Here we present how these challenges can be overcome, and present additional evaluation steps to ease the interpretation of the temperature-dependent hysteresis data.
Homogenization of global early instrumental data
Authors: Lundstad Elin
Published: March 2022

Instrumental meteorological observations are crucial for the analysis of climate backwards in time to reconstruct climate variations. However, the collection of instrumental data dating back to 1658 allows many of the long climate series to have often been affected by inhomogeneities (artificial shifts) due to changes in measurement conditions (relocations, instrumentation, change in environment, etc.). To deal with this problem, homogenization procedures have been developed to detect and adjust inhomogeneities. Homogenization in climate research means the removal of non-climatic changes. Next to changes in the climate itself, raw climate records also contain non-climatic jumps and changes for example due to relocations or changes in instrumentation.

This presentation describes the homogenization of the early instrumental dataset (HCLIM) of monthly mean temperature time series and other parameters such as precipitation and air pressure.

New homogenization algorithm validation methodology will be assessed by early instrumental data, and its use to assess the skills of three different algorithms, when applied to early instrumental data. The methods tested were PHA, HOMER and SPLIDHOM.
Estimable phase and code biases in the frame of global multi-GNSS processing
Authors: Strasser Sebastian , Mayer-Gürr Torsten , Süsser-Rechberger Barbara , Dumitraschkewitz Patrick
Published: March 2022

Signal biases are hardware delays that occur during the transmission and reception of GNSS signals. On the satellite side, there is a delay between the generation of a signal and its transmission at the antenna. The same is the case on the receiver side, where a delay occurs between signal reception at the antenna and the actual measurement of a specific signal in the receiver. As the name suggests, code biases refer to the delays affecting code observations. Similarly, phase observations are affected by phase biases. In general, signal biases differ per constellation, satellite, frequency, signal attribute, as well as receiver hardware and settings.

The main issue with signal biases is that they are usually not known. Therefore, they have to be estimated during GNSS processing. However, the relative nature of GNSS observations prevents the estimation of absolute signal biases. This results in several rank deficiencies in the normal equation system when signal biases are estimated together with other geodetic parameters in a global multi-GNSS processing.

We present a general approach based on eigenvalue analysis to solve these rank deficiencies. Therefore, the co-estimation of pseudo-absolute transmitter and receiver signal biases in our multi-GNSS processing becomes possible. This approach also enables ambiguity resolution of GLONASS phase obervations.
Presenting the Groundwater Time Series Modeling Challenge
Authors: Haaf Ezra , Collenteur Raoul , Liesch Tanja , Bakker Mark
Published: March 2022

Groundwater level time series are the most common source of information on the dynamics of subsurface water resources. The modeling of such time series is of crucial importance to increase our understanding of the system and make predictions on future changes. This becomes ever more important with global challenges such as climate change and human over-exploitation of groundwater resources. Different types of models can be applied to model groundwater level time series, ranging from purely statistical models (black-box), through lumped conceptual models (grey-box), to physically based models (white-box). Traditionally, physically based, distributed models are predominantly used to solve groundwater problems. In recent years, the use of grey- and black-box models has been receiving increased attention. In this poster we will present the “Groundwater Time Series Modeling Challenge”, which aims to systematically compare different methodologies to model groundwater level time series. We challenge researchers to model a predefined set of groundwater time series observed in unconsolidated aquifers worldwide, set in a variety of physiographic and climatic conditions. Participating groups are free to use the model of their choice, but are required to use the same forcing data and periods for calibration. Model performance will be centrally assessed by the organizers using non-public validation data set, which will be made public after the challenge. A more detailed description of the rules for this challenge and all groundwater and forcing data is available in a GitHub repository at https://github.com/gwmodeling/challenge. The results of the challenge will be presented at the General Assembly of the EGU in 2023 and reported in a peer-reviewed paper. With this challenge, we hope to increase the awareness in the groundwater community about all the different types of models that are available to model groundwater level time series.
New stations to monitor gas hazard in the ongoing volcanic unrest crisis of La Fossa volcano (Vulcano Island, Italy)
Authors: Carapezza Maria Luisa , Amend Detlef , Fisher Christian , Pruiti Lucia , Ranaldi Massimo , Tarchini Luca , Weber Konradin
Published: March 2022

La Fossa volcano, located in the Vulcano Island of the Aeolian Archipelago, is the type locality of Vulcanian explosive eruptions. It last erupted in 1888-1890 and since then it is affected by an intense fumarolic activity from both the summit crater area and a hydrothermal site (Levante Beach) located very near to the main settlement of the island (Vulcano Porto). In Autumn 2021 a potential volcanic unrest crisis began with a strong increase of steam, CO2 and SO2 emission from the high-T crater fumaroles, ground uplift and episodic anomalous seismicity. Vulcano Porto inhabited area is exposed to gas hazard either from the wind dispersed crater fumarolic plume (mostly CO2 and SO2) and from anomalous diffuse soil gas emissions in Levante Beach and other zones of Vulcano Porto village (mostly CO2 and eventually H2S). The gas hazard of the village was considered so high that in December 2021 Civil Protection prohibited residents to stay at home during the night. In order to improve the monitoring of gas hazard we developed new stations continuously measuring the air concentration of CO2 and SO2. Each of these stations is operating with an electrochemical sensor for the measurement of SO2 and a photoacoustic sensor for the measurement of CO2. Moreover, atmospheric pressure, temperature and humidity are monitored in parallel to the gas measurements. The measured data are sent continuously via mobile data connection to a dedicated server. By this means the measured parameters can be monitored remotely, without the need to access the site personally. Three stations were installed (at 1 m from the ground) in mid-December 2021 in three sites of Vulcano Porto; two of them were located at the base of La Fossa cone in the sector most exposed to the crater gas plume, while a third station was located in the heart of the village, near the church. Results show that CO2 exceeds of few hundreds ppm the normal air value of 400 ppm in all the stations. In some occasions, during night in absence of wind or with light wind blowing from SW, some peaks of both CO2 and SO2 were recorded in all the stations (CO2 max 1500 ppm; SO2 max 2 ppm). Additionally a future server sided extension to our system is planned, which integrates an early warning system, that can send email alerts, if certain thresholds are exceeded.
Vegetation feedbacks enhance the West African Monsoon during the Mid-Holocene
Authors: Berntell Ellen , Zhang Qiong
Published: March 2022

Proxy records have shown that the Mid-Holocene was a period of humid conditions across West Africa, with an enhanced West African Monsoon (WAM) reaching far into the Sahara region and with vegetation covering areas currently characterized by desert leading to conditions being referred to as the Green Sahara. However, General Circulation Models struggle with recreating this strengthened Mid-Holocene monsoon, and the results from the latest PMIP4 simulations showed a clear underestimation of the rainfall enhancement across the Sahel and Sahara region. Understanding what physical processes drive the variability of the WAM, and including those processes in our simulations, might aid in closing this gap. The vegetation-albedo feedback has long been viewed as an important process modulating the monsoon variability in West Africa, and simulations using prescribed vegetation to recreate a Green Sahara have exhibited a strengthening of the WAM and increased rainfall. However, these simulations represent an idealised vegetation cover based on proxy records found along the west coast of West Africa and do not take any environmental heterogeneity into account. Furthermore, this only represents a one-directional forcing by the vegetation on the climate, rather than the vegetation-albedo feedbacks. This might therefore over-/underestimate the changes of the WAM, as well as over-/understate the importance of the vegetation feedbacks. To address this, we have simulated the Mid-Holocene (~6 ka) climate using the high-resolution Earth System Model EC-Earth3-Veg. The results show that coupled dynamic vegetation reproduce a clear enhancement of the WAM when compared to simulations with a prescribed modern vegetation cover. This enhances warming of the Sahara region and deepens the Sahara Heat Low resulting in increased rainfall and strengthened monsoonal flow across West Africa. However, the enhancement is still below what can be viewed in proxy reconstructions which highlights the importance of investigating additional processes, such as including interactive aerosol-albedo feedbacks.
Passive margin asymmetry and its polarity in the presence of a craton
Authors: Gudipati Raghu , Pérez-Gussinyé Marta , Andres-Martinez Miguel , Neto-Araujo Mario , Phipps Morgan Jason
Published: March 2022

When continental lithosphere is extended to break-up it forms two conjugate passive margins. In many instances, these margins are asymmetric: while one is wide and extensively faulted, the conjugate thins more abruptly and exhibits little faulting. Recent studies have suggested that this asymmetry results from the formation of an oceanward-dipping sequential normal fault array and rift migration leading to the observed geometry of asymmetric margins. Numerical models have shown that fault sequentiality arises as a result of asymmetric uplift of the hot mantle towards the hanging wall of the active fault. The preferential localization of strain reinforced by strain weakening effects is random and can happen on either conjugate. However, along the long stretch of the South Atlantic margins, from the Camamu-Gabon to the North Santos-South Kwanza conjugates, the polarity can be very well correlated with the distance of the rift to nearby cratonic lithosphere. Here, we use numerical experiments to show that the presence of a thick cratonic root inhibits asthenospheric flow from underneath the craton towards the adjacent fold belt, while flow from underneath the fold belt towards the craton is favoured. This enhances and promotes sequential faulting and rift migration towards the craton and resulting in a wide faulted margin on the fold belt and a narrow conjugate margin on the craton side, thereby determining the polarity of asymmetry, as observed in nature.
Deriving storage of small and medium-sized reservoirs with elevation datasets and medium-resolution satellite imagery
Authors: Donchyts Gennadii , Winsemius Hessel , de Jong Tjalling , Moreno-Rodenas Antonio , Pronk Maarten
Published: March 2022

Small and medium-sized reservoirs play an important role in water systems that help cope with climate variability. Although reservoirs and dams are criticized for their negative social and environmental impacts by reducing natural flow variability and obstructing river connections, they are also recognized as important for social and economic development and climate change adaptation. These reservoirs are crucial to the well-being of many societies worldwide, but regular monitoring records of their water dynamics are mostly missing. Multiple studies exist which look into the quantification of water stored in the reservoirs behind these dams. Still, very few studies focus on small and medium-sized reservoirs globally. In this research, we present the current status of the research focusing on the derivation of storage for small and medium-sized reservoirs. We use multi-annual multi-sensor satellite data with up to daily observation frequency, combined with cloud analytics, derive dynamics and storage of small (10-100ha) to medium-sized (>100ha) artificial water reservoirs globally. We derive storage by combining multiple datasets such as water occurrence, surface water area dynamics observed from space, and several elevation datasets available globally such as ALOS, NASADEM, EU-DEM. We evaluate the applicability of ICESat-2 and GEDI LiDAR sensors to estimate water storage in these reservoirs, perform validation for more than 700 reservoirs globally, and assess the applicability of these datasets to monitor water storage for more than 70 000 reservoirs globally.
 Spatially continuous landform driven reconstruction of marginal retreat dynamics of the Southern and Eastern sectors of the last Fennoscandian Ice Sheet, beyond the hard bedrock shield
Authors: Diemont Christiaan R , Clark Chris D , Livingstone Stephen J , Hughes Anna L C
Published: March 2022

The last Fennoscandian Ice Sheet provides a valuable scenario for testing and evaluating numerical ice sheet models with a large amassed database of landform, stratigraphic and dated evidence of ice sheet activity. In contrast to the core shield area (Norway, Sweden and Finland) of the ice sheet, fewer investigations beyond the shield (Denmark, Germany, Poland, Lithuania, Latvia, Estonia and Russia) attempt to gather local to regional information into ice sheet wide syntheses of ice margin and lobe dynamics. For example, many detailed investigations across these countries remain disconnected with adjacent areas applying varying methods and naming schemes making it difficult to reconcile at the ice sheet scale.

Here we present a systematic and spatially coherent reconstruction of ice margin dynamics for the whole southern and eastern margin, from Denmark to arctic Russia. The landform to reconstruction method allows for a consistent approach to be applied to the 1.2+ million km2 mapping area despite a wide range of glaciological landform and data variability (DEM vary in resolution from 0.4 m-25 m) found in the 1.2+ million km2 study area. We propose this reconstruction as a first-order framework of ice marginal dynamics that can be used to develop second-order and more detailed knowledge of fluctuations when more closely connected to stratigraphic and geochronometric investigations. Rather than a simple concentric retreat pattern often envisaged the landform record and its frequent overprinting forces a solution of complexity with lobe interactions and readvances.
Diverging simulated effects of future drought stress on the Amazon rainforest 
Authors: Papastefanou Phillip , Pugh Thomas , Buras Allan , Eckes-Shephard Annemarie , Fleischer Katrin , Grams Thorsten , Gregor Konstantin , Hickler Thomas , Krause Andreas , Lapola David , Liu Daijun , Zang Christian , Rammig Anja
Published: March 2022

The Amazon rainforest is the largest intact tropical forest ecosystem and stores about 120 Pg of carbon. To this day, it acts as a carbon sink by taking up carbon from the atmosphere, however, long-term observations show a decline in strength of this carbon sink, a trend that at current rates would likely lead to the Amazon basin becoming a carbon source around year 2050. The reasons for this declining trend are disputed, increasing temperatures and more frequent and intense droughts are becoming the potential drivers. Vegetation modelling offers a possibility to disentangle the effects of these drivers, however, most Dynamic Global Vegetation Models (DGVMs) or Earth System Models (ESMs) are still not able to reproduce this observed carbon sink decline and the correct response of vegetation to drought stress. Here, we apply a new version of the DGVM LPJ-GUESS with improved plant hydraulics. It is one of the few state-of-the-art DGVMs that can successfully (1) capture the carbon dynamics under severe drought stress and (2) reproduce the current observed declining trend of the carbon sink. We investigate whether the Amazon rainforest will recover its sink strength or turn into a carbon when driven by climate projection source from the latest Inter-Sectoral Impact Model Intercomparison Project (ISIMIP 3a), using multiple forcing datasets. The simulations show strongly diverging response patterns of the Amazon rainforest that depend on both the selected emission scenario (e.g. SSP5-8.5 or 1-2.6) and the climate model (e.g. UKESM vs. ESM4). Using the SSP5-8.5 scenarios we find higher drought-induced carbon losses in the second half of the 21st century compared to the first half of the century. However, these losses are partly (e.g. ESM4) or completely (e.g. UKESM) outweighed by higher carbon gains induced by higher CO2 concentrations. Our findings highlight the complex interplay of CO2 fertilization, higher atmospheric dryness (more negative vapour pressure deficit) and its effects on stomatal conductance. 
Volcano-ice interaction:  The empirical constraints derived from eruptions in Iceland in the period 1918-2015
Authors: Gudmundsson Magnus Tumi , Högnadóttir Thórdís , Magnússon Eyjólfur , Reynolds Hannah I , Larsen Guðrún , Pálsson Finnur
Published: March 2022

Eruptions where glacier ice has a significant effect on the style of activity occur in some parts of the world, notably the Andes, Alaska, parts of Antarctica and Iceland.  Due to its northerly latitude and considerable ice cover within the volcanically active zones, about 50% of all eruptions in Iceland occur within glaciers, which is about 15 such eruptions per century.  In the last 25 years, six such confirmed eruptions have taken place while only one minor confirmed eruption occurred in the period 1938-1996.  This is due to the episodic nature of activity in the volcanoes covered by the 7900 km2 Vatnajökull ice cap, with a new period of high activity starting with the Gjálp eruption of 1996.   Contemporary observations have therefore provided considerable empirical data on these events.  These data include glacier thickness prior to eruptions, ice cauldron development, glacier flow perturbations, melting rates and transitions from fully subglacial to explosive/partly subaerial eruptions.  In addition, some data exist that constrains the volcano-ice interaction in the eruptions of Katla in 1918, Grímsvötn in 1934 and 1983, Gjálp in 1938 and Hekla in 1947.  The majority of these events were basaltic.  However, at least two eruptions that had an initial fully subglacial phase (Gjálp 1996, Eyjafjallajökull 2010) were of intermediate composition.  The volume of subglacially-erupted magma ranged from a few million m3 to 0.45 km3 (DRE), initial ice thicknesses ranging from 50 to 750 m, and melted ice volumes between 0.01 km3 to 4 km3.  Combined, the data from the eruptions of the last 100+ years, provides important constraints on heat transfer rates, the rate of penetration of eruptions through ice, glacier response to eruption, and the potential for generation of jökulhlaups and lahars.  Post-eruption observations in Grímsvötn have revealed that craters formed in eruptions that break through the glacial cover can be partly built on ice.  These tend to be highly transient features due subsequent melting and ice movement.  Surface melting of ice by pyroclastic density currents has occurred in Iceland, but this type of activity has in the recent past mostly been confined to the occasional sub-Plinian to Plinian eruptions in e.g. Hekla volcano.   However, there are indications that such activity has played an important role in some relatively rare large Plinian eruptions at ice covered volcanoes in Iceland, as observed in e.g. Alaska and the Andes.
Microbiological impacts of hydrogen injection into underground storages
Authors: Wagner Martin , Nowack Guido , Pretzien Theresa , Krasper Lydia
Published: March 2022

As the integration of wind and solar energy increases, so does the need for large-volume and efficient storage to balance fluctuations in power generation and demand.

In order to meet this demand, the proportional injection of renewable hydrogen into the natural gas grid or directly into underground storage facilities (UGS) is already being investigated in several pilot studies. Large-scale hydrogen storage, especially in salt caverns, is considered to have great potential in the context of carbon-free energy supply. From microbiological studies of numerous cavern and porous storage facilities, it is known that most UGS are already colonized with microorganisms that can use hydrogen as their sole energy source.

The results of several research projects and analyses of numerous underground storage facilities with regard to the stimulation potential of existing microorganisms give clear indications of associated risks. The results of these studies also contradict the widespread assumption that saturated brine in caverns generally provides sufficient protection against microbial colonization.

Long-term analyses with over 70 active cultures enriched from different underground storage and reservoir samples and tests with original formation waters show significant hydrogen consumption even in saturated brine with simultaneous H2S formation by SRB. Carbonates from the minerals of the rock matrix can be used as a necessary carbon source. For a practical simulation of hydrogen storage, in addition to microcosm experiments, numerous high-pressure tests were carried out at storage-relevant conditions over several months with original brine and core samples from different storage types. In some cases, considerable hydrogen conversions and sulfide formation rates were found.

In addition to the influence of hydrogen injection on microorganisms in storage facilities, two projects are also investigating dedicated biological methanogenesis in 11 porous UGS. Presence of microorganisms was detected in almost all reservoirs. Active methanogenic archaea were enriched from three facilities and their ability for methanogenesis was studied and confirmed under different conditions (pressure, temperature, salinity). However, microorganisms with competing metabolic pathways were also detected (e.g. sulfate reducers and acetogens).

The presentation summarizes the results of microbiological investigations on storage and reservoir samples from more than 10 years and gives an overview of relevant microbial processes and their potential impact on technical operations.
Pulsations of the Azores anticyclone at intra-seasonal scale: how oceanic waves and coastal wind anomalies combine constructively to force the variability of the north-eastern boundary upwelling system in winter-spring.
Authors: Sané Badara , Lazar Alban , Wade Malick , Gaye Amadou Thierno
Published: March 2022

The Azores High shows a strong intra-seasonal variability that, transmitted to the whole North Atlantic by the Trade Wind, generates a multi-factor variability of the Canary Islands eastern edge upwelling system. In this work, we study the cold season (March to April), using satellite observations and numerical simulation, and how the variability of the wind at the equator, the Kelvin and coastal waves, and the local wind along the North-West African coast combine
to force upwelling variability. Composite analyses show how, in 80% of the cases, the pulsations of the anticyclone at 40 d excite equatorial waves that arrive in the Senegalese upwelling 15 d later, precisely at the time of the phase change of coastal wind anomalies.  These waves trapped at the coast, from upwelling or downwelling, reinforce the local wind anomaly. The intra-seasonal variability of the SST is thus the result of a double local and remote effect whose respective contributions we quantify 