bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate impact on radon risk for silty loam soils 
Authors: Valdes-Abellan Javier , Gil-Oncina Sara , Pla Concepción , Galiana-Merino Juan José , Benavente David
Published: March 2021

Radon isotope 222Rn constitutes a natural source of radioactivity, which is worldwide extended and can be found, regardless its concentration in almost all soils of the Earth surface. Inhale radon gas is a risk for human health and the World Health Organization, WHO, has concluded the doubtless correlation between long exposure to radon gas and lung cancer; even more, the US-EPA considers it as the second most important cause of lung cancer in USA., The adoption of preventive measurements during building construction is extending in many developed countries because long exposure to radon gas take place mainly in poorly ventilated basements. Generally, these measures are based on radon risk associated exclusively with radon production by soils, but less attention are devoted to the impact of soil gas permeability and, even more, of the variable soil gas permeability because of the different degrees of soil water contents. Soil water content affects soil permeability to both water and vapor phases, and it must be taken into consideration when defining the risk associated to the presence of radon. In the present study, we show the importance of different climate conditions on soil water content and in turn on the gas permeability. We tested with the radon potential risk of building sites of the Czech Republic, which combines both the radon concentration in soil and soil gas permeability (Neznal et al, 2004). According to the Köppen classification, the present study considers different climatic scenarios: Bsk, hot semiarid climate, typical from many regions in South Europe; Csa, temperate Mediterranean climate with dry hot summers and moderate winters, also common in South Europe; Cfb, oceanic humid climate with great extension in France and UK; and finally Dfb, humid continental climate with cool winters and moderate summers, typical from central Europe.

Soil water content for each scenario was simulated using HYDRUS. Average values were obtained from a 100-year temporal series.  The top most 1-m thick layer was considered as the representative for the soil water content. Results demonstrate the necessity to consider water content when defining the radon risk and their interannual variability, especially for those climates with very clear different precipitation patterns along the different seasons.
A retrospective of the work of Patience Cowie: the interaction of faults in space and time and their influences on subsurface fluid flow, surface processes and earthquakes
Authors: Shipton Zoe
Published: March 2021

Patience Cowie was a truly outstanding scientist whose research spanned several disciplines of structural geology and tectonics. She made a lasting contribution to every discipline she published in and as well as academic advances, produced significant impacts in the hydrocarbon industry and earthquake hazard assessment. Her research in fault mechanics and fault population was a genuine game-changer. The implications of her work for predicting fault patterns and linkage have been crucial for the interpretation of 3D seismic data, and for examining the interplay between faults and the basins they bound and sediments they host. More recently she explored relationships between fault geometry, slip rate and recurrence intervals along seismically active faults, with important implications for earthquake hazard assessment.

Patience’s drive to constrain physical explanations of the underlying dynamics of Earth processes meant her numerical modelling was always firmly grounded in field observations. Her models incorporated the effects of stress in time and space as fault system evolved, but always underpinned by geometric and kinematic observations in the field. She loved fieldwork and her joy at the beauty of geological structures was infectious and inspiring.  
Analysis of the evolution of Martian polar caps during Martian Years 34-35 from Mars Express Visual Monitoring Camera
Authors: del Río-Gaztelurrutia Teresa , Sánchez-Lavega Agustín , Hernández-Bernal Jorge , Angulo Ainhoa , Hueso Ricardo , Cardesín-Moinelo Alejandro , Martin Patrick , Wood Simon , Titov Dmitri
Published: March 2021

The wide field of view of the Visual Monitoring Camera (VMC) onboard Mars Express, together with the polar orbit of the spacecraft, make VMC very suitable to monitor polar phenomena on Mars1. During Martian Years 34 and 35, Martian polar regions were imaged regularly by VMC, and in this work we use this set of images to analyze the evolution of both north and south polar ice caps. We determine the limits of the ice cap at different longitudes and the total area covered by ice as the season evolves, and we analyze the possible influence of the Global Dust Storm in the evolution of the ice caps regression curves. Finally, we describe a number of mid-scale atmospheric features that develop at the edge of the polar caps.

1 Hernandez-Bernal et al. ”The 2018 Martian Global Dust Storm Over the South Polar Region Studied With MEx/VMC” Geophys. Res. Lett. 46, pp 10330-10337 (2019)
Decadal changes in the Atlantic Meridional Overturning Circulation in high-resolution simulations of the subpolar North Atlantic
Authors: Böning Claus W. , Biastoch Arne , Getzlaff Klaus , Wagner Patrick , Rühs Siren , Schwarzkopf Franziska U. , Scheinert Markus
Published: March 2021

A series of global ocean - sea ice model simulations is used to investigate the spatial structure and temporal variability of the sinking branch of the meridional overturning circulation (AMOC) in the subpolar North Atlantic. The experiments include hindcast simulations of the last six decades based on the high-resolution (1/20°) VIKING20X-model forced by the CORE and JRA55-do reanalysis products, supplemented by sensitivity studies with a 1/4°-configuration (ORCA025) aimed at elucidating the roles of variations in the wind stress and buoyancy fluxes. The experiments exhibit different multi-decadal trends in the AMOC, reflecting the well-known sensitivity of ocean-only models to subtle details in the configuration of the subarctic freshwater forcing. All experiments, however, concur in that the dense, southward branch of the overturning is mainly fed by “sinking” (in density space) in the Irminger and Iceland Basins, in accordance with the first results of the OSNAP observational program. Remarkably, the contribution of the Labrador Sea has remained small throughout the whole simulation period, even during the phase of extremely strong convection in the early 1990s: i.e., the rate of deep water exported from the subpolar North Atlantic by the DWBC off Newfoundland never differed by more than O(1 Sv) from the DWBC entering the Labrador Sea at Cape Farewell. The model solutions indicate a particular concentration of the sinking along the deep boundary currents south of the Denmark Straits and south of Iceland, pointing to a prime importance for the AMOC of the outflows from the Nordic Seas and their subsequent enhancement by the entrainment of intermediate waters. Since these include the water masses formed by deep convection in the Labrador and southern Irminger Seas, our study offers an alternative interpretation of the dynamical role of decadal changes in Labrador Sea convection intensity in terms of a remote effect on the deep transports established in the outflow regimes.
Using sub-daily timelapse imagery to investigate the behaviour of Narsap Sermia, SW Greenland.
Authors: Fahrner Dominik , Lea James , Brough Stephen , Abermann Jakob
Published: March 2021

Greenland’s tidewater glaciers (TWG) have been retreating since the mid-1990s, contributing to mass loss from the Greenland Ice Sheet and sea level rise. Satellite imagery has been widely used to investigate TWG behaviour and determine the response of TWGs to climate. However, multi-day revisit times make it difficult to determine short-term processes such as calving and shorter-term velocity changes that may condition this. 

Here we present velocity, calving and proglacial plume data derived from hourly time-lapse images of Narsap Sermia, SW Greenland for the period July 2017 to June 2020 (n=13,513). Raw images were orthorectified using the Image GeoRectification And Feature Tracking toolbox (ImGRAFT; Messerli & Grinsted, 2015) using a smoothed ArcticDEM tile from 2016 (RMSE=44.4px). TWG flow velocities were determined using ImGRAFT feature tracking, with post-processing adjusting for varying time intervals between image acquisitions (if >1 hour) and removing outliers (>x2 mean). The high temporal resolution of the imagery also enabled the manual mapping of proglacial plume sizes from the orthorectified images and the recording of individual calving events by visually comparing images.

Results show a total retreat of approximately 700 m, with a general velocity increase from ~15 m/d to ~20 m/d over the investigated time period and highly variable hourly velocities (±12m/d). The number of calving events and plume sizes remain relatively stable from year to year throughout the observation period. However, later in the record plumes appear earlier in the year and the size of calved icebergs increases significantly, which suggests a change in calving behaviour. 
Rainfall monitoring in Sri Lanka employing commercial microwave links
Authors: Overeem Aart , Leijnse Hidde , van Leth Thomas , Bogerd Linda , Priebe Jan , Tricarico Daniele , Droste Arjan , Uijlenhoet Remko
Published: March 2021

Microwave backhaul links from cellular communication networks provide a valuable “opportunistic” source of high-resolution space–time rainfall information, complementing traditional in situ measurement devices (rain gauges, disdrometers) and remote sensors (weather radars, satellites). Over the past decade, a growing community of researchers has, in close collaboration with cellular communication companies, developed retrieval algorithms to convert the raw microwave link signals, stored operationally by their network management systems, to hydrometeorologically useful rainfall estimates. Operational meteorological and hydrological services as well as private consulting firms are showing an increased interest in using this complementary source of rainfall information to improve the products and services they provide to end users from different sectors, from water management and weather prediction to agriculture and traffic control. The greatest potential of these opportunistic environmental sensors lies in those geographical areas over the land surface of the Earth with few rain gauges and no weather radars: often mountainous and urban areas, but especially low- to middle-income regions, which are generally in (sub)tropical climates. 

Here, the open-source R package RAINLINK is employed to retrieve CML rainfall maps covering the majority of Sri Lanka, a middle-income country having a tropical climate. This is performed for a 3.5-month period based on CML data from on average 1140 link paths. CML rainfall maps are compared locally to hourly and daily rain gauge data, as well as to rainfall maps from the Dual-frequency Precipitation Radar on board the Global Precipitation Measurement Core Observatory satellite. The results confirm the potential of CMLs for real-time tropical rainfall monitoring. This holds a promise for, e.g., ground validation of or merging with satellite precipitation products.
The root-fungus interplay in foraging for heterogeneous sources
Authors: Stiblíková Pavlína , Weiser Martin , Jansa Jan
Published: March 2021

The distribution of nutrients in the soil is very heterogeneous at different scales relevant to plant roots, and plants respond to this heterogeneity by the architecture of the root system. The ability to form the root system in terms of the most effective nutrient uptake differs among species. Moreover, over 70% of terrestrial plants create arbuscular mycorrhizal symbiosis, which helps them to acquire nutrients from the soil. It has been shown that plants with mycorrhizal symbiosis acquire nutrients from heterogeneous soil differently than plants without mycorrhizal fungi. Our study aims to estimate the link between the root and fungal foraging for heterogeneous sources using an experimental approach. We show the root foraging precision of nine plant species together with three fungal species in the heterogeneous soil environment. The first results suggest that root foraging is not affected by the presence of mycorrhizal fungi and that fungal foraging may form in the opposite direction than root foraging.
Increasing tropical cyclone intensity and potential intensity in the subtropical Atlantic around Bermuda from an ocean heat content perspective 1955- 2019
Authors: Hallam Samantha , Guishard Mark , Josey Simon , Hyder Pat , Hirschi Joel
Published: March 2021

Here we investigate tropical cyclone (TC) activity and intensity within a 100km radius of Bermuda between 1955 and 2019. Our results show a more easterly genesis over time and significant increasing trends in tropical cyclone intensity (maximum wind speed (Vmax)) with a decadal Vmax median value increase of 30kts from 33 to 63kts, together with significant increasing August, September, October (ASO) sea surface temperature (SST) of 1.1°C (0.17 °C per decade)  and ocean temperature between 0.5–0.7°C (0.08-0.1°C per decade)  in the depth range 0-300m. The strongest correlation is found between TC intensity and ocean temperature averaged through the top 50m ocean layer (T50m) r=0.37 (p<0.01). 

We show how tropical cyclone potential intensity estimates are closer to actual intensity by using T50m opposed to SST using the Bermuda Atlantic Timeseries Hydrostation S dataset. We modify the widely used sea surface temperature potential intensity index by using T50m to provide a closer estimate of the observed minimum sea level pressure (MSLP), and associated Vmax than by using SST, creating a T50m potential intensity (T50m_PI) index. The average MSLP difference is reduced by 12mb and proportional to the SST/ T50m temperature difference. We also suggest the index could be used over a wider area of the subtropical/tropical Atlantic where there is a shallow mixed layer depth. Finally, we outline the TC wind-pressure relationship observed for the subtropical Atlantic around Bermuda, explaining 77% of the variance, which may prove useful for future prediction.

(Environmental Research Letters, 2020, in revision)

 

 
Preliminary results of the first assessment of 20 years of dust activity in the Patagonia desert (South America) with aerosol products from the MODIS sensors
Authors: Gassó Santiago , Gupta Pawan , Ginoux Paul , Levy Robert
Published: March 2021

Aerosol transport processes in the Southern Hemisphere (SH) have been the center of renewed attention in the last two decades because of a number of major geophysical events such as volcanic eruptions (Chile and Argentina), biomass burning (Australia and Chile) and dust storms (Australia and Argentina).

While volcanic and fire activity in the SH have been the focus of several studies, there is a dearth of satellite assessments of dust activity. The lack of such analysis impairs the understanding of biological processes in the Southern Ocean and of the provenance of dust found in snow at the surface of East Antarctica.

This presentation will show an analysis of time series of Aerosol Optical Depths over the Patagonia desert in South America. Data from two aerosol algorithms (Dark Target and Deep Blue) will be jointly analyzed to establish a timeline of dust activity in the region. Also, dust proxies from both algorithms will be compared with ground-based observations of visibility at different airports in the area. Once an understanding of frequency and time evolution of the dust activity is achieved, first estimations of ocean-going dust fluxes will be derived.
Challenges in correctly assessing fracture growth in subsurface applications
Authors: Nejati Morteza , Sakha Mahsa , Bahrami Bahador , Ghouli Saeid , Ayatollahi Majid R. , Driesner Thomas
Published: March 2021

Accurate predictions of fracture growth path resulted from fluid injection in subsurface is an important topic in geoscience projects such as wastewater injection, CO2 sequestration and geothermal energy extraction. Pressurised fluid not only creates new fractures in form of hydraulic fractures, but also potentially propagates pre-existing ones. A precise assessment of fracture growth path is pivotal in characterising the connectivity of the fracture network, and as a result, the hydraulic response of the rock volume. Numerical modelling provides a strong platform to help better understand fracture growth path during hydraulic stimulations. Despite significant progress in the computational power and advanced numerical algorithms in recent years, the numerical simulation of fracture growth still faces many challenges. Some of these challenges are related to the robustness of the numerical schemes used to model evolving fractures. The development of methods such as extended finite element and phase-field have greatly helped in recent years to tackle the evolution of fractures in complex trajectories. A second group of challenges is related to the development of accurate fracturing laws and their implementation into numerical codes in order to obtain realistic fracture growth trajectories. In this paper, we address some of the challenges in the second group and share our findings on how we can more accurately predict fracture path in subsurface. At first, we present our evaluation of the measured values of the fracture toughness in laboratory, and discuss why those values are mostly underestimating fracture toughness in rock masses. We then introduce a method to correct these values, that are obtained from small laboratory-sized specimens, to be able to use them in numerical codes that predict fracture growth in large rock volumes in subsurface. The second contribution is related to the rock anisotropy and its influence on the fracture growth path. We present experimental results on the anisotropy of fracture toughness, and show how important it is to take into account the directional-dependence of fracture toughness when modelling fracture growth in anisotropic formations. Lastly, the third contribution is to distinguish between tension-based and shear-based fracture growth mechanisms. Most numerical models in literature use the maximum tangential stress criterion to predict fracture growth path. We show that this criterion is not able to predict shear-based fracturing that often occurs in the subsurface. We conclude that a reliable numerical code needs to implement a fracturing law that is able to predict both tensile- and shear-based fracturing types.
A 30-year reconstruction of the Atlantic meridional overturning circulation shows no decline.
Authors: Worthington Emma , Moat Ben , Smeed David , Mecking Jennifer , Marsh Robert , McCarthy Gerard
Published: March 2021

A decline in Atlantic meridional overturning circulation (AMOC) strength has been observed between 2004 and 2012 by the RAPID array with this weakened state of the AMOC persisting until 2017. Climate model and paleo-oceanographic re-search suggests that the AMOC may have been declining for decades or even centuries before this, however direct observations are sparse prior to 2004, giving only ‘snapshots’ of the overturning circulation. Previous studies have used linear models based on upper layer temperature anomalies to extend AMOC estimates back in time, however these ignore changes in the deep circulation that are beginning to emerge in the observations of AMOC decline. Here we develop a higher fidelity empirical model of AMOC variability based on RAPID data, and associated physically with changes in thickness of the persistent upper, intermediate and deep water masses at 26°N and associated transports. We applied historical hydrographic data to the empirical model to create an AMOC time series extending from 1981 to 2016. Increasing the resolution of the observed AMOC toapproximately annual shows multi-annual variability in agreement with RAPID observations, and that the downturn between 2008 and 2012 was the weakest AMOC since the mid-1980s. However, the time series shows no overall AMOC decline asindicated by other proxies and high resolution climate models. Our results reinforce that adequately capturing changes to thedeep circulation is key to detecting any anthropogenic climate change-related AMOC decline
Short-Term Forecast of Harmful Algal Blooms on the West Florida Shelf
Authors: Liu Yonggang , Weisberg Robert H. , Zheng Lianyuan , Hubbard Katherine
Published: March 2021

A short-term forecast tool is developed to help federal, state, and local end users monitor and manage harmful algal blooms on the west coast of Florida. The short-term forecasts are based on the West Florida Coastal Ocean Model (WFCOM) that downscales from the deep ocean, across the continental shelf and into the estuaries, and the Tampa Bay Coastal Ocean Model (TBCOM) that has resolution high enough to include all of the inlets connecting Tampa Bay, Sarasota Bay and the Intra-Coastal Waterway with the adjacent Gulf of Mexico. Observed Karenia brevis cell concentration data are uploaded daily into the WFCOM and TBCOM to generate 3.5 day forecasts of the bloom Lagrangian trajectories on the shelf and in the estuaries. This provides information where red tide may go in the next few days. Noting that the spatial red tide sampling is limited and blooms may be patchy, a more general and user-friendly map is produced to show where a red tide bloom may occur along the coast over the next several days. The tracking tool displays modeled bloom trajectories at the surface and the bottom with five categories of cell concentrations (present, very low, low, medium, and high, each differing approximately by an order of magnitude). The performance of the Lagrangian trajectory model is evaluated with satellite-tracked surface Lagrangian drifters using a skill score that is defined from the normalized cumulative Lagrangian separation (NCLS).
Bayesian Hierarchical Modeling of Sea Level Extremes on the Finnish Coast
Authors: Räty Olle , Laine Marko , Leijala Ulpu , Särkkä Jani , Johansson Milla
Published: March 2021

Coastal cities are going through rapid and challenging changes. Accurate estimates of probabilities of extreme sea levels are a highly valuable asset to face flooding hazards and support safe planning of coastal zones in the future climate. Probabilities of specific extreme events have been traditionally estimated from the observed extremes independently at each tide gauge location. However, this approach has shortcomings. Firstly, sea level observations often cover a relatively short historical time period and thus contain only a small number of extreme cases (e.g. annual maxima). This causes substantial uncertainties when estimating the distribution parameters. Secondly, exact information on sea level extremes between the tide gauge locations and incorporation of dependencies of adjacent stations is often lacking in the analysis.

One way to partially tackle these issues is to exploit spatial dependencies exhibited by the sea level extremes. These dependencies emerge from the fact that sea level variations are often driven by the same physical and dynamical factors at the neighboring stations. Bayesian hierarchical modeling offers a way to model these dependencies. The model structure allows to share information on sea level extremes between the neighboring stations and also provides a natural way to represent modeling uncertainties.

In this study, we use Bayesian hierarchical modeling to estimate return levels of annual sea level maximum on the Finnish coast, located in the northeast parts of the Baltic Sea. As annual maxima are studied, we use the generalized extreme value (GEV) distribution as the basis of our model. To tailor the model specifically for the target region, spatial dependencies are modeled using covariates, which reflect the distinct geometry of the Baltic Sea. We also account for inter-annual and decadal-scale variations in the distribution parameters by including teleconnection indices such as North Atlantic oscillation (NAO) in our model. Preliminary results show that hierarchical modeling provides added value in comparison to the traditional approach, when applied to the available long-term tidegauge time series in Finland. The work presented here is a part of project PREDICT (Predicting extreme weather and sea level for nuclear power plant safety) that supports nuclear power plant safety in Finland.
Effect of non-tidal station loading on Lunar Laser Ranging observatories and on the estimation of Earth orientation parameters
Authors: Singh Vishwa Vijay , Biskupek Liliane , Müller Jürgen , Zhang Mingyue
Published: March 2021

The distance between the observatories on Earth and the retro-reflectors on the Moon has been regularly observed by the Lunar Laser Ranging (LLR) experiment since 1970. In the recent years, observations with bigger telescopes (APOLLO) and at infra-red wavelength (OCA) are carried out, resulting in a better distribution of precise LLR data over the lunar orbit and the observed retro-reflectors on the Moon, and a higher number of LLR observations in total. Providing the longest time series of any space geodetic technique for studying the Earth-Moon dynamics, LLR can also support the estimation of Earth orientation parameters (EOP), like UT1. The increased number of highly accurate LLR observations enables a more accurate estimation of the EOP. In this study, we add the effect of non-tidal station loading (NTSL) in the analysis of the LLR data, and determine post-fit residuals and EOP. The non-tidal loading datasets provided by the German Research Centre for Geosciences (GFZ), the International Mass Loading Service (IMLS), and the EOST loading service of University of Strasbourg in France are included as corrections to the coordinates of the LLR observatories, in addition to the standard corrections suggested by the International Earth Rotation and Reference Systems Service (IERS) 2010 conventions. The Earth surface deforms up to the centimetre level due to the effect of NTSL. By considering this effect in the Institute of Geodesy (IfE) LLR model (called ‘LUNAR’), we obtain a change in the uncertainties of the estimated station coordinates resulting in an up to 1% improvement, an improvement in the post-fit LLR residuals of up to 9%, and a decrease in the power of the annual signal in the LLR post-fit residuals of up to 57%. In a second part of the study, we investigate whether the modelling of NTSL leads to an improvement in the determination of EOP from LLR data. Recent results will be presented.
Digital Mapping of Soil Particle Size Distribution in an Alluvial Plain Using the Random Forest Algorithm
Authors: Kaya Fuat , Başayiğit Levent
Published: March 2021

Soil maps are an important source of data in monitoring natural resources and land use planning. However, in many countries, soil maps were prepared at a reconnaissance level. This detail is not enough for land use planning. Soil texture is one of the most important soil physical properties that affect water holding capacity, nutrient availability, and crop growth. The spatial distribution of soil texture at a high resolution is essential for crop planning and management. Digital soil mapping is the method of spatial data generation with the advantages of current technologies. It supplies fast, accurate, and reproducible results.

In this study, a soil texture map with 30 m spatial resolution was produced for an alluvial plain covering an area of approximately 10,000 ha. In the study, 11 Topographic Environmental Variables obtained from NASA's ASTER Global Digital Elevation model were used. Another input parameters were clay, silt, and sand values determined for 91 soil samples obtained through field studies.

R Core Environment (3.6.1) and related packages were used for environmental variable extraction, modeling, and spatial mapping. For model building, 70 % of data was used and the rest of the data was used for validation. Random Forest Algorithm offers interpretability for pedological information extraction by determining the importance of environmental variables in digital soil mapping. Random Forest Algorithm is preferred because of working in small data sets, harmoniously. The most important topographic environmental variables for clay were elevation, aspect, and slope. For sand, it was the elevation, aspect, and topographic wetness index. And for silt, it was the elevation, slope length, and planform curvature. Root Mean Square Error (RMSE), was used as a model performance measure. In the train data, R2 values for clay, sand and silt were 0.84, 0.75, 0.85 and RMSE values were 5.23 %, 3.03 %, 5.48 % respectively. In the test data, R2 and RMSE values were 0.26, 0.11, 0.10 and 11.8 %, 6.74 %, 13.71 % respectively.

There are high differences between RMSE values of training and test data sets. This event may be caused by the small sample size and to be discussed subject in different studies. High resolution (30 m) data of clay, silt, and sand contents can be useful for hydrological studies and for the preparation of land use plans. Digital soil maps can guide policymakers in creating site-specific land management plans. As well as it can be used for monitoring soil fertility and providing ecosystem services. This study revealed important results regarding the use of digital soil mapping in practice with its analytical and statistical accuracy.
Simulating catchment scale river discharges and flood events from large scale atmospheric information: Example of the Upper Rhône River (European Alps)
Authors: Legrand Caroline , Hingray Benoît , Wilhelm Bruno
Published: March 2021

Floods are highly destructive natural hazards causing widespread impacts on socio-ecosystems. This hazard could be further amplified with the ongoing climate change, which will likely alter magnitude and frequency of floods. Estimating how flood regimes could change in the future is however not straightforward. The classical approach is to estimate future hydrological regimes from hydrological simulations forced by time series scenarii of weather variables for different future climate scenarii. The development of relevant weather scenarii for this is often critical. To be adapted to the critical space and time scales of the considered basins, weather scenarii are thus typically produced from climate models with downscaling models (either dynamic or statistical).

In this study, we aim to evaluate the capacity of such a simulation chain to reproduce floods observed in the upper Rhône River (10900 km², European Alps) over the last century. The modeling chain is made up of (i) the atmospheric reanalysis ERA-20C (1900-2010), (ii) the statistical downscaling model Analog, and (iii) the glacio-hydrological model GSM-SOCONT (Glacier and Snowmelt SOil CONTribution model; Schaefli et al., 2005). To assess the performance of this modeling chain, the simulated scenarii of mean areal precipitation and temperature are compared to the observed time series over the common period (1961-2010), whereas the discharge scenarii are compared to the reference time series (1920-2010).

In this presentation, we will discuss (i) the results obtained by the basic Analog method, namely a flood events underestimation due to an underestimation of extreme precipitation values, in particular 3-day and 5-day extreme precipitation, and (ii) the enhanced results obtained by the improved version of Analog SCAMP (Sequential Constructive Atmospheric Analogues for Multivariate weather Predictions; Raynaud et al., 2020) combined to the Schaake Shuffle method.

References:

Schaefli, B., Hingray, B., M. Niggli, M., Musy, A. (2005). A conceptual glacio-hydrological model for high mountainous catchments. Hydrology and Earth System Sciences Discussions, European Geosciences Union, 9, 95-109.

Raynaud, D., Hingray, B., Evin, G., Favre, A.-C., Chardon, J. (2020). Assessment of meteorological extremes using a synoptic weather generator and a downscaling model based on analogues. Hydrology and Earth System Sciences Discussions, European Geosciences Union, 24(9), 4339-4352.
Urban DAS recording of a vibroseismic campaign with a 21km-long dark fibre in Potsdam, Germany
Authors: Krawczyk CharLotte , Wollin Christopher , Lüth Stefan , Lipus Martin , Cunow Christian , Siebert Ariane , Jousset Philippe , Fuchs Sven
Published: March 2021

The de-carbonization strategy of the city of Potsdam, Germany, incorporates the utilization of its geothermal potential.  As a first step of developing a deep geothermal project for district heating, an urban seismic exploration campaign of the Stadtwerke Potsdam took place in December 2020 in the city centre of Potsdam.  Since urban measurements are often difficult to setup and a low-footprint alternative is sought for, we supplemented the contractor-performed Vibroseis survey along three profiles by distributed acoustic sensing (DAS).  In close cooperation with the municipal utilities, we interrogated a 21 km-long dark telecommunication fibre whose trajectory followed the seismic lines as close as possible.  This was accompanied by a network of 15 three-component geophones for further control and research.

In this contribution we present the data set, the approach for geo-referencing the fibre, and first results regarding DAS recording capabilities of vibroseismic signals in an urban environment.  Following the paradigm that the high density of telecommunication networks in urban areas may facilitate the exploration of the often insufficiently known local geology, we strive to further shed light on the possibilities of their employment for urban exploration.  In this respect we aim at tackling the question of the accuracy of fibre localization, recording sensitivity and range of active stimulation.
How to publish your data with the EPOS Multi-scale Laboratories
Authors: ter Maat Geertje , Lange Otto , Drury Martyn ,   EPOS TCS Multi-scale Laboratories Team
Published: March 2021

EPOS (the European Plate Observing System) is a pan-European e-infrastructure framework with the goal of improving and facilitating the access, use, and re-use of Solid Earth science data. The EPOS Thematic Core Service Multi-scale Laboratories (TCS MSL) represent a community of European Solid Earth sciences laboratories including high-temperature and high-pressure experimental facilities, electron microscopy, micro-beam analysis, analogue tectonic and geodynamic modelling, paleomagnetism, and analytical laboratories. 

Participants and collaborating laboratories from Belgium, Bulgaria, France, Germany, Italy, Norway, Portugal, Spain, Switzerland, The Netherlands, and the UK are already represented within the TCS MSL. Unaffiliated European Solid Earth sciences laboratories are welcome and encouraged to join the growing TCS MSL community.

Laboratory facilities are an integral part of Earth science research. The diversity of methods employed in such infrastructures reflects the multi-scale nature of the Earth system and is essential for the understanding of its evolution, for the assessment of geo-hazards, and the sustainable exploitation of geo-resources.

Although experimental data from these laboratories often provide the backbone for scientific publications, they are often only available as images, graphs or tables in the text or as supplementary information to research articles. As a result, much of the collected data remains unpublished, not searchable or even inaccessible, and often only preserved in the short term.

The TCS MSL is committed to making Earth science laboratory data Findable, Accessible, Interoperable, and Reusable (FAIR). For this purpose, the TCS MSL encourages the community to share their data via DOI-referenced, citable data publications. To facilitate this and ensure the provision of rich metadata, we offer user-friendly tools, plus the necessary data management expertise, to support all aspects of data publishing for the benefit of individual lab researchers via partner repositories. Data published via TCS MSL are described with the use of sustainable metadata standards enriched with controlled vocabularies used in geosciences. The resulting data publications are also exposed through a designated TCS MSL online portal that brings together DOI-referenced data publications from partner research data repositories (https://epos-msl.uu.nl/). As such, efforts have already been made to interconnect new data (metadata exchange) with previous databases such as MagIC (paleomagnetic data in Earthref.org), and in the future, we expect to enlarge and improve this practice with other repositories. 
New findings regarding the ground air circulation by chimney effect in low-altitude permafrost susceptible porous screes (Detunata Goală, Romanian Carpathians)
Authors: Popescu Răzvan , Vespremeanu-Stroe Alfred , Vasile Mirela , Andrian Ilie , Calisevici Sabina , Niculiță Bogdan
Published: March 2021

Seasonally differentiated ground air circulation in low altitude porous talus slopes from temperate regions known as chimney circulation creates the conditions for permafrost development in their lower parts well below the regional permafrost altitudinal limit. So far it was shown that the cold air adsorption and warm air exfiltration areas during winter correspond to the lower and upper areas respectively of talus slopes and that they are quite stable and regular in extent and shape. New aerial survey in early winter at Detunata Goală scree with a complex talus slope-rock glacier morphology performed immediately in the days following light snow falls allowed the precise detection of warm air areas positions, shape and temporal changes within hours and days. Several triangular-shaped stripes were found to occur continuously from lower to upper parts of talus slopes and morphometric analysis on a high resolution UAV-derived DEM revealed that they correspond to 1the central longitudinal axis of debris cones composing the talus slopes. Thermal monitoring of air between the blocks was also performed at the location of these stripes where a thermal gradient was found to occur: the atmospheric/ground air temperature contrast increases upwards and towards the axis of talus cones reaching a maximum of >10 °C (+5.3 °C in the ground versus -5 °C outside). In the rock glacier lobe area, the warm air evacuation is different and presents a linear configuration. This work discusses the relation between the morphometry of the deposit and warm air evacuation areas and their short term thermal regime. Also, it discusses new geophysical investigations results (electrical resistivity tomography and seismic refraction tomography) performed at the end of the warm season of 2020 in the coldest area of the scree.
Modeling FoRTE, the Forest Resilience Threshold Experiment
Authors: Dorheim Kalyn , Bond-Lamberty Ben , Gough Chris , Haber Lisa , Shiklomanov Alexey
Published: March 2021

Forested ecosystems represent a large yet uncertain fraction of the global terrestrial carbon sink. Their future state depends on a number of natural and anthropogenic influences; a particularly large uncertainty is how disturbance affects vegetation structure and ecosystem biogeochemistry.  We used the Ecosystem Demography model to explore the ecological and biogeochemical consequences of disturbance as part of the Forest Resilience Threshold Experiment (FoRTE), a dual modeling and manipulative field experiment investigating the effects of disturbance at different severities on a century-old deciduous forest. The field component was conducted at the University of Michigan Biological Station (UMBS), where stem girdling was applied to achieve four different severity levels of disturbance (0, 45, 65, and 85% gross defoliation) before the 2019 growing season. Since then, we have tracked the subsequent changes in vegetation and biogeochemistry. The modeling component attempted to simulate the FoRTE disturbance treatments within its framework. While we were able to instantiate a forest in ED with a similar climatology, soil characteristics, disturbance history, and vegetation of UMBS,  baseline ED is ultimately unable to reproduce the vegetation dynamics and carbon fluxes observed at the UMBS control plots. This is consistent with previous work where the model is not capable of matching observed carbon and vegetation dynamics. However, ED’s response to the disturbance treatments is consistent with observations from UMBS: in both the model and UMBS experimental results, we observed different resiliences and carbon cycle responses with respect to disturbance severity. These intriguing results point to both weaknesses and new possibilities in the modeling of ecosystems facing rising disturbances and climate change.
Evolution of the Alu-Dalafilla and Borale Volcanoes, Afar, Ethiopia
Authors: Watts Emma J. , Gernon Thomas M. , Taylor Rex N. , Keir Derek , Siegburg Melanie , Jarman Jasmin , Pagli Carolina , Gioncada Anna
Published: March 2021

The Danakil depression in the Afar region of Ethiopia marks the change from subaerial continental rifting to seafloor spreading further north in the Red Sea [1]. Extension and volcanism in this incipient spreading centre is localised to the ~70-km-long, 20-km-wide active Erta Ale volcanic segment (EAVS), with multiple volcanic centres consisting of a combination of fissures, shield volcanoes and stratovolcanoes [2]. This study aims to better understand the nature of interaction between three volcanoes with the EAVS (Alu, Dalafilla and Borale) while also investigating their evolution during the transition from continental to oceanic crustal production.

Here we combine results of mapping, using remote sensing, and geochemical analysis of Alu, Dalafilla and Borale in the northern half of the EAVS. Multispectral images were used to create a high-resolution map and establish a relative chronology of lava flows. Our results show that the majority of flows are sourced from a combination of scoria cones and fissures, representing in total 15 phases of volcanism within four major eruptive stages.

The first stage represents large-scale fissure volcanism comprising basaltic phases that erupted in a submarine environment. Stage two involves basaltic fissure volcanism centred around the Alu dome. The third stage is dominated by trachy-andesite to rhyolitic (SiO2 of 59-70%) volcanism sourced from the volcanic edifices of Alu, Dalafilla and Borale. The fourth and final stage is characterised by a resumption of small-scale basaltic/trachybasalt (SiO2 of 49-55%) fissure eruptions.

Geochemical modelling indicates a paucity of crustal assimilation and mixing within the sub-volcanic magmatic system. Spatial analysis of volcanic cones and fissures within the area indicate the presence of a cone sheet and ring faults. The fissures are likely fed by sills connecting the magma source with the volcanic edifices of Alu and Borale. Our results reveal the cyclic nature of both eruption style and composition of major volcanic complexes in rift environments, prior to the onset of seafloor spreading.

References

[1] Wolfenden et al. (2005) EPSL 224:213-228

[2] Barberi and Varet (1970) Bull Volcanologique 34:848-917
Rheological Bridge Zone: Initialization of Localization
Authors: Feng He , Gerbi Christopher , Johnson Scott
Published: March 2021

Strain localization occurs throughout the crust, in both the brittle and viscous regimes. The causes of strain localization remain under discussion. However, realistic rock records indicate that variations of material properties (e.g. active deformation mechanisms, crystallographic orientation, phase distribution, grain shapes, etc.) are likely to be the dominant factor for weakening. Determining the cause(s) of localization requires investigation of the earliest stages of strain concentration in different P-T conditions. Our study focuses on two rocks that experienced low macroscale strain at amphibolite and/or granulite facies conditions yet exhibit localization on the millimeter and smaller scale. We combine optical and electron beam petrography with chemical mapping and electron backscatter diffraction to characterize these rheologically important domains. Morphologically, these localized zones appear to mechanically link rheologically weak phases or domains. These “bridge” zones typically comprise a band of relatively fine grains with weak crystallographic preferred orientation. The major element compositions of like phases inside and outside the bridge zone are similar, but the modal mineralogy and trace elements vary somewhat. Bridge zones result from not only in-situ grain size reduction (due to, for example, nucleation, recrystallization, or cataclasis), but also chemical processes resulting in phase mixing or element mobility on a short spatial scale. Their spatial distribution suggests that the small modal fraction of microstructural change represented by the bridge zones can lead to a high degree of bulk weakening.
Magnetosheath jet evolution as a function of lifetime: Global hybrid-Vlasov simulations compared to MMS observations
Authors: Palmroth Minna , Raptis Savvas , Karlsson Tomas , Suni Jonas , Turc Lucile , Johlander Andreas , Ganse Urs , Pfau-Kempf Yann , Blanco-Cano Xochitl , Akhavan-Tafti Mojtaba , Battarbee Markus , Grandin Maxime , Dubart Maxime , Tarvus Vertti , Osmane Adnane
Published: March 2021

Magnetosheath jets are regions of high dynamic pressure, which can traverse from the bow shock towards the magnetopause. Recent modelling efforts, limited to a single jet and a single set of upstream conditions, have provided the first estimations about how the jet parameters behave as a function of position within the magnetosheath. Here we expand the earlier results by making the first statistical investigation of the jet dimensions and parameters as a function of their lifetime within the magnetosheath. To verify the simulation behaviour, we first identify jets from Magnetosphere Multi-Scale (MMS) spacecraft data (6142 in total) and confirm the Vlasiator jet general behaviour using statistics of 924 simulated individual jets. We find that the jets in the simulation are in excellent quantitative agreement with the observations, confirming earlier findings related to jets using Vlasiator. The jet density, dynamic pressure and magnetic field intensity show a sharp jump at the bow shock, which decreases towards the magnetopause. The jets appear  compressive and cooler than the magnetosheath at the bow shock, while during their propagation towards the magnetopause they thermalise. Further, the shape of the jets flatten as they progress through the magnetosheath. They are able to maintain their flow velocity and direction within the magnetosheath flow pattern, and they end up preferentially to the side of the magnetosheath behind the quasi-parallel shock. Finally, we find that Vlasiator jets during low solar wind Alfvén Mach number (MA) are shorter in duration, smaller in their extent, and weaker in terms of dynamic pressure and magnetic field intensity as compared to the jets during high MA. 