bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term response of benthic foraminifera to fine sediment depositional events simulated in microcosm
Authors: Corentin Guilhermic , Maria Pia Nardelli , Hélène Howa , Damien Le Moigne , Antonio Pusceddu , Sophie Sanchez , Aurélia Mouret
Published: March 2022

An in vitro experiment was designed to describe how benthic foraminifera (as witness of the benthic ecosystem) reacts to “one-time high volume” vs “frequent low volume” sediment discharge, as it may occur in coastal benthic environments regularly or occasionally buried during (e.g.) river flood massive deposits, or glacier melting events in polar regions. The influence of these events on the ecology of benthic ecosystems is often neglected and the resilience of benthic foraminiferal communities is poorly known. During a 53-day long experiment in microcosm, the NE Atlantic mudflat foraminifera community, mainly represented by Ammonia T6 and Haynesina germanica species, was confronted to two kinds of sedimentary disturbance: 1) one-time high volume (OHV) deposit, i.e. about 3 cm thick sediment is added in one time at the beginning of the experiment, and 2) frequent low volume (FLV) deposits, i.e. about 0.5 cm added each week for 4 weeks. The geochemical environment (e.g. O2 penetration in the sediment, salinity, temperature and nutrient content in the supernatant water) was monitored to follow its steady-state before and during the experiment. In the two studied cases, the foraminifera react to the disturbance by immediately moving upward to the surface within 1 day after the deposit. In the OHV treatment, a species vertical distribution in relation to the surface, comparable to the vertical distribution before the disturbance (i.e. a resilient state), is established at most 1 week after the deposit, and no effects are visible on the foraminiferal diversity after 1 month experiment (without any other sediment input). In the FLV treatment, the resilient state is already reached 1 day after a low thickness burial. This suggests that foraminifera can migrate rapidly to their preferential life position under the new sediment-water interface. However, after 4 recurrent burring events the density of H. germanica drastically decreases, changing in this way the foraminiferal community structure. The results of this microcosm experiment suggest that the entire foraminiferal community can migrate upward quickly enough to keep pace with at least 3 cm of abrupt burial but needs several days to reach a resilient state. Furthermore, frequent sediment deposition may affect foraminiferal biodiversity more than a massive erratic event.
Using anthropogenic gadolinium as a tracer to reduce the risk for contamination of river bank filtration systems
Authors: Marazuela Miguel Angel , Brünjes Robert , Tepe Nathalie , Formentin Giovanni , Erlmeier Klaus , Hofmann Thilo
Published: March 2022

Drinking water systems providing water to large cities are frequently located in alluvial or fluvio-glacial aquifers because their high permeability allows high extraction rates. Under normal conditions, these systems are recharged by river bank filtration and groundwater is collected at a sufficient distance to ensure that filtration through the aquifer provides water of good quality. However, during flood events, infiltration from the river bank may increase reducing the transit time, which may result in a higher risk of contamination. Identifying the water origin and its path from the river to the water work is key to establish operational strategies that minimize or prevent contamination during flood events. In this study, we investigate the potential of using anthropogenic gadolinium, which is increasingly used as a contrast agent in magnetic resonance imaging (MRI) and finally verted into rivers, as a conservative tracer to identify pathways of river bank filtration and then contribute to minimize the uncertainty of numerical models.

The test site is located in a rural sub-alpine basin. Several horizontal drains extract water from a fluvio-glacial aquifer by gravity. Under normal conditions, good quality water is collected; during flood events, due to the sudden increase in infiltration and decrease in transit times, water quality might deteriorate, as shown by the appearance of E. coli and coliforms. The concentration of anthropogenic gadolinium was measured in the river, in observation wells, and in the extracted drinking water over several years. The results demonstrated the great potential of gadolinium to identify and delineate the infiltration plumes produced by river bank filtration, which is contributing to reduce model uncertainty and evaluate the best pumping strategy for each of the drains in order to prevent water quality degradation.
Simulating the evolution of the Antarctic Ice Sheet including 3D GIA feedback during the Last Glacial Cycle
Authors: van Calcar Caroline , van de Wal Roderik , Blank Bas , de Boer Bas , van der Wal Wouter
Published: March 2022

Changes in ice load over time deform the Earth’s crust and mantle. This effect, Glacial Isostatic Adjustment (GIA), induces vertical deformation of the bedrock of the Antarctic continent and impacts the grounding line position which is critical for the dynamical state of the Antarctic Ice Sheet (AIS). GIA introduces a negative feedback and stabilizes the ice sheet evolution, hence GIA modelling is important for transient studies. Most ice dynamic models use a two-layer flat Earth approach with a laterally homogenous relaxation time or a layered Earth approach with a laterally homogenous viscosity (1D) to compute the bedrock deformation. However, viscosity of the Earth’s interior varies laterally (3D) and radially with several orders of magnitude across the Antarctic continent. Here we present a new coupled 3D GIA – ice dynamic model which can run over hundred thousands of years with a resolution of 500 years. The method is applied using various 1D and 3D rheologies. Results show that the present-day ice volume is 3 % lower when using a 1D viscosity of 1021 Pa·s than using a 3D viscosity. However, local differences in grounding line position maybe up to a hundred kilometres around the Ronne and the Ross Ice Shelfs, and ice thickness differences are up to a kilometre for present day conditions when comparing 1D rheologies and 3D rheologies. The difference between the use of various 3D rheologies is significantly smaller. These results underline and quantify the importance of including local GIA feedback effects in ice dynamic models when simulating the Antarctic Ice Sheet evolution over the Last Glacial Cycle.
Automated detection of gravitational instabilities by combining seismology, satellite data and machine learning - example over the European Alps.
Authors: Groult Charlotte , Hibert Clément , Malet Jean-Philippe
Published: March 2022

Recent large landslides in many parts of the World (Nuugaatsiaq, Greenland; Taan-Tyndall, US; Culluchaca, Peru) as well as the increase in the frequency of gravitational instability in the European Alps (e.g. collapse of the Drus, Mont Blanc Massif, France) revealed the threat of such events to human activity. Seismology provides continuous recordings of landslides activity on long distances. High frequency time series of satellite imagery (Copernicus Mission Sentinel) provides relevant complementary information to locate, identify the type of gravitational instability and gather information on the volume of the event. The objective of this work is to present a new method to automatically construct instrumental landslide catalogs by combining seismological and satellite observations using machine learning approaches. This new type of landslide catalog will provide an unprecedented spatio-temporal resolution over a long time period allowing to explore possible correlations between landslide activity and forcing (meteorological, climatic, tectonic) factors. 

The detection method applied to the seismological observations consists of computing the energy of the signal between 2 and 10 Hz on which a STA/LTA method is applied. Detections are refined by applying the Kurtosis picking method. Detections which are too close (< 2 min) are combined. For the processing of continuous seismic data, detections are considered as an event if at least 2 stations recorded them at the same time. Then, a supervised Random Forest classifier is used to identify the source of the event (earthquakes or landslides). The landslide database, used to train the Random Forest classifier, consists of 68 events that occured in the last 20 years over the entire European Alps. A database of 7914 earthquakes (of MLv > 0.1) that occured in 2020 has also been compiled in order to train the classifier in order to discriminate landslides and earthquakes. Thus, a dataset of 2502 seismological traces of landslides and 39540 traces of earthquakes is used to train and test the seismological detection and identification methods. First tests of our processing chain gave us a rate of good identification of around 80% for landslides and 99% for earthquakes. 

The model is then applied to the archive of seismological observations (e.g. 1800 stations in 2021) acquired over the European Alps since 2000. To avoid having too many noise detections, we chose to keep an event in the new landslide catalog only if it is detected and classified as a landslide by at least two stations in a time window of 4 minutes. The derived instrumental catalog will be presented, and the sensitivity of the method will be discussed.
Optimization of preventive drought management measures to alleviate the severity of agricultural and hydrological droughts
Authors: Paez ana , Corzo Gerald , Solomatine Dimitri
Published: March 2022

Preventive Drought Management Measures (PDMM) aim to reduce the chance of droughts and minimise their negative consequences in the short and long term. A wide range of interventions can be considered PDMM, including Nature-Based Solutions, grey infrastructure, land use management, and soil conservation practices, among others. This study intends to apply an optimisation procedure to find optimal combinations and allocations of PDMM that contribute to minimising the agricultural and hydrological drought's severity at a basin scale. To achieve this goal, we coupled the multi-objective genetic algorithm (NSGA-II) with the semi-distributed hydrologic model, Soil and Water Assessment Tool (SWAT). The PDMM evaluated in this study are rainwater harvesting ponds, parallel terraces, forest conservation, grade stabilisation structures and floodplains restoration. Preliminary results indicate that optimal combinations and allocations of PDMM reduce the drought's severity in downstream subbasins. The analysis was developed in the La Vieja basin (West-central Colombia).
Comparison of normal fault slip to long-term landscape building. Insights from morphometry analysis and geochronological data on the Magnola-Velino fault system (central Apennines, Italy)
Authors: Desormeaux Clement , Godard Vincent , Benedetti Lucilla , Fleury Jules
Published: March 2022

Active faults play a major role in relief building, partly through the accumulation of vertical co seismic displacement during major earthquakes. Triangular facets are geomorphic features recording normal fault cumulative displacements on relatively long time scales (10-100ka). To unravel the relationships between the rate at which slip accumulates on a fault scarp and the long-term evolution of triangular facets, we have to acquire quantitative datasets on normal fault slip rates at various timescales and rates of erosion of the facets.

Here we present a study on facet build-up over 10-100 ka time range in the central Apennines in Italy. The normal fault systems that control the present tectonic activity of the range are very well studied with numerous detailed paleoseismological records. We focus on the Magnola-Velino fault system which displays well preserved triangular facets and accurate chronological constraints on the 10-20m high fault scarp located at the base of the facets. We combine high resolution morphometric analysis (gullies steepness, facets slope and others), using Digital Elevation Models derived from Pléiades imagery and a new dataset for cosmogenic nuclides concentration (36Cl) including 54 bedrock samples on 9 gullies and facets profiles above the scarps. Magnola-Velino fault system is 20-25km long, and morphometric parameters such as steepness index display a systematic evolution along strike. First measured 36Cl concentrations, on Magnola, range from 6 to 50 x104 at/g on gullies and 50 to 150 x104 at/g on facets, with systematic variations along strike. We document the joint evolution of geochronological data and morphological parameters for this fault system and compare it with existing constraints on long-term slip rate.
Upper Pleistocene sea level changes and human peopling at the northern margin of the Mediterranean Sea: the S-P-Heritage Project
Authors: Zerboni Andrea , Bollati Irene M. , Forti Luca , Gazzo Silvia , Moussous Abdelkader , Muttoni Giovanni , Negrino Fabio , Notter Olivier , Pelfini Manuela , Perego Alessandro , Perini Serena , Ragaini Luca , Regattieri Eleonora , Rossoni-Notter Elena , Rovere Alessio , Ryan Deirdre , Serradimigni Marco , Starnini Elisabetta , Vacchi Matteo , Pappalardo Marta
Published: March 2022

Since the Pleistocene, the Mediterranean is a hot spot for climate change and human migrations, thus offering the opportunity to investigate how human populations have responded to environmental changes and sea level variations. This is the main topic of the SPHeritage Project (MUR grant: FIRS2019_00040, P.I.: M. Pappalardo) that proposes an interdisciplinary approach to investigate the human-environment interaction (in particular sea level variations) over the last 400,000 years using a combination of micro-invasive methods. The Project is re-investigating the well-known archaeological area of ​​the Balzi Rossi (Ventimiglia, at the border between Italy and France), which represents a unique assemblage of archaeological sites dating to the Palaeolithic, distributed in a geomorphological setting rich of markers of past sea level changes. As most of the local archaeological sequences have been extensively investigated at the beginning of the last century and large part of the deposits removed, we will combine the analyses of materials preserved in museums (including strips of sediments) and the remnants still preserved inside many rockshelters and caves of the archaeological complex. Moreover, our geomorphological survey identified new sedimentary sequences preserving information on relative sea level changes. This approach will permit to obtain innovative data submitting small samples to state-of-the-art methods for dating and palaeoenvironmental reconstruction, thus offering the opportunity to better constrain the time and steps of climate change, sea level oscillations, and human settlements. Moreover, data will converge into geoheritage analyses aimed at finding the best practices for promoting and protecting the site. Here, we present an overview of the project and preliminary results from some of the major archaeological sites.
Quantifying volcanism and organic carbon burial across Oceanic Anoxic Event 2 
Authors: Papadomanolaki Nina M. , van Helmond Niels A.G.M. , Paelike Heiko , Sluijs Appy , Slomp Caroline P.
Published: March 2022

Oceanic Anoxic Event 2 (ca. 94 Ma; OAE2) was one of the largest Mesozoic carbon cycle perturbations, but associated carbon emissions, primarily from the Caribbean large igneous province (LIP) and marine burial fluxes, are poorly constrained. Here, we use the carbon cycle box model LOSCAR-P to quantify the role of LIP volcanism and enhanced marine organic carbon (Corg) burial as constrained by the magnitude and shape of the positive stable carbon isotope (δ13C) excursion (CIE) in the exogenic carbon pool and atmospheric pCO2 reconstructions. In our best fit scenario, two pulses of volcanic carbon input—0.065 Pg C yr–1 over 170 k.y. and 0.075 Pg C yr–1 over 40 k.y., separated by an 80 k.y. interval with an input of 0.02 Pg C yr–1—are required to simulate observed changes in δ13C and pCO2. Reduced LIP activity and Corg burial lead to pronounced pCO2 reductions at the termination of both volcanic pulses, consistent with widespread evidence for cooling and a temporal negative trend in the global exogenic δ13C record. Finally, we show that observed leads and lags between such features in the records and simulations are explained by differences in the response time of components of the carbon cycle to volcanic forcing.  
Adaptive volcanic modelling using Discontinuous Galerkin Methods
Authors: Bänsch Michel , Behrens Jörn
Published: March 2022

Since the Eyjafjallajökull eruption in 2010, the volcanic modelling community has been focused on improving the prediction of ash dispersion and simulation of eruptive columns.
While many new and powerful numerical methods have been developed for Computational Fluid Dynamics (CFD) and Atmospheric Modelling, very few have been integrated into models for volcanic eruptions.
Conventional models usually lack high spatial resolution if the distance to the volcanic vent is large and (mostly) cannot represent shocks. Both of these problems need to be dealt with by using new CFD techniques.

In contrast to algorithms which are currently available in the volcanic modelling community,
this work focuses on implementing different spatial discretization methods - Discontinuous Galerkin Methods (DGM) instead of Finite Volume Methods or Finite Difference Methods - while also using Adaptive Mesh Refining (AMR) techniques.
This combination eliminates both resolution problems (due to AMR) and the lack of shock capturing (due to DGM).
Gas dynamics are described by either using the Euler or Navier-Stokes Equations while the AMR utilizes h-adaptivity with a suitable error estimation. 
Time-integration is performed with (explicit) Runge-Kutta (SSPRK or LSRK) methods.

We will present results that show the ability to model eruptions and present challenges that arise with both CFD and AMR approaches in volcanic modelling.
Comparing machine-learning based picking algorithms in a subduction setting
Authors: Najafipour Nooshin , Sippl Christian
Published: March 2022

As the number of seismic stations and experiments greatly increases due to ever greater availability of instrumentation, automated data processing becomes more and more necessary and important. Machine Learning (ML)methods are becoming widespread in seismology, with programsthat identify signals and patterns or extract features that can eventually improve our understanding of ongoing physical processes. We here focus on comparing and testing a selection of currently available methods for machine-learning-based seismic event detection and arrival time picking, performing a comparative study of the two autopickers EQTransformer and GPD with seismic data from the IPOC deployment in Northern Chile within the open-source Seisbench framework.

As a small benchmark dataset, we chose a random day for which we handpicked all visually discernible events on the 16 IPOC stations, which led to 200 events from 450 extracted, comprising 1493 P and 1163 S-phases. These events cover a large range of hypocentral depths (surface to >200 km) as well as magnitudes (<1.5 to 4.5).

We present first results from the application of the two autopickers EQTransformer and GPD, which have been shown to be most suitable for our type of dataset in a recent study by Münchmeyer et al. (2021), to IPOC data. We use our small benchmark dataset to evaluate detection rate (missed events, false detections) as well as picking accuracy (residuals to handpicks), and also investigate the effect of using different training datasets.

The present study is the first step towards the design of an automated workflow that comprises event detection and phase picking, phase association and event location and will be used to evaluate subduction zone microseismicity in different locations.
A methodology for the analysis of InSAR Time Series for the detection of ground deformation events
Authors: Pedretti Laura , Bordoni Massimiliano , Vivaldi Valerio , Figini Silvia , Parnigoni Matteo , Grossi Alessandra , Lanteri Luca , Tararbra Mauro , Negro Nicoletta , Meisina Claudia
Published: March 2022

The availability of Sentinel-1 dataset with high-temporal resolution of measures (6-12 days) and long time period, can be considered as a “near-real-time monitoring” since it provides a sampling frequency enough to track the evolution of some ground deformations (e.g. landslides, subsidence) if compared to other sensors. However, the analysis and elaborations of such huge dataset, covering large areas, could be tricky and time-consuming without a first exploitation to identify areas of potential interest for significant ground deformations. The A-InSAR Time Series (TS) interpretation is advantageous to understand the relation between ground movement processes and triggering factors (snow, heavy rainfall), both in areas where it is possible to compare A-InSAR TS with in-situ monitoring instruments, and in areas where in situ instruments are scarce or absent. Exploiting the availability of Sentinel-1 data, this work aims to develop a new methodology ("ONtheMOVE" - InterpolatiON of SAR Time series for the dEtection of ground deforMatiOneVEnts) to classify the trend of TS (uncorrelated, linear, non-linear); to identify breaks in non-linear TS; to provide the descriptive parameters (beginning and end of the break, length in days, cumulative displacement, the average rate of displacement) to characterize the magnitude and timing of changes in ground motion. The methodology has been tested on two Sentinel-1 datasets available from 2014 to 2020 in Piemonte region, in northwestern Italy, an area prone to slow-moving slope instabilities. The methodology can be applied to any type of satellite datasets characterized by low or high-temporal resolution of measures, and it can be tested in any areas to identify any ground instability (slow-moving landslides, subsidence) at local or regional scale. The thresholds used for event detection should be calibrated according to geological and geomorphological processes and characteristics of a specific site or regional site. This innovative methodology provides a supporting and integrated tool with conventional methods for planning and management of the area, furnishing a further validation of the real kinematic behaviour of ground movement processes of each test-site and where it is necessary doing further investigation. In addition, elaboration applied to Sentinel-1 data is helpful both for back analysis and for near real-time monitoring of the territory as regards the characterization and mapping of the kinematics of the ground instabilities, the assessment of susceptibility, hazard and risk.
Granular porous landslide tsunami modelling with OpenFOAM
Authors: Rauter Matthias , Viroulet Sylvain , Gylfadóttir Sigríður  Sif , Løvholt Finn , Fellin Wolfgang
Published: March 2022

Subaerial landslides are among the most complex sources for tsunamis, as several complex processes occur simultaneously in various regimes, with multiple phases interacting. The simulation and prediction of these events is respectively difficult.

We will present a three-dimensional multiphase model (granules, air, water) that considers the  effects and properties that we deem most important: (i) a sharp water-air interface with low diffusivity, (ii) granular rheology for the landslide, (iii) differentiation between effective pressure and pore pressure, as well as (iv) porosity, dilatancy and permeability. No depth-integration or other form of simplification is applied. The resulting mathematical model is solved with the fluid dynamics toolkit OpenFOAM.

Many effects and processes that are lost in depth-integrated models are directly simulated in our approach. This allows the simulation of complex events with a relatively simple model, however for a large computational cost. The model parameters are widely intrinsic material parameters, which promises a prediction of events without significant parameter optimizations.

We will show results for small scale experiments as well as for a well documented real scale event and will give an outlook on further developments and remaining problems.
Post-land abandonment management through shrub clearing practices as a tool for enhancing soil quality and carbon storage. 
Authors: Cortijos-López Melani , Sánchez-Navarrete Pedro , Errea Paz , Lasanta Teodoro , Nadal-Romero Estela
Published: March 2022

Land abandonment is outstanding as one of the main causes of soil degradation in Mediterranean mid-mountains. This process is closely linked to the rural exodus that took place in the middle of the last century, that led to the activation of natural revegetation mechanisms and massive shrub encroachment. Consequently, several ecosystem disservices have been identified, such as homogenization of landscape, loss of biological and cultural diversity, decrease in water-human-consume resources, reduction of agropastoral resources and higher wildfire risk. However, the effects on soil environment are multiple and controversial. Thus, a case study in the Leza Valley (La Rioja, Spain) has been selected to analyse the effects of post-land abandonment management through shrub clearing practices in soil quality, carbon dynamics and carbon sequestration, in order to give a second chance to these marginalised areas while fighting against Global Change.

For the soil sampling, 5 land uses have been selected: control pasture, 3 shrub clearing sites of different ages; and shrubland after cropland abandonment (6 replicates at different depths, 0-40 cm, have been collected at each study site). Physico-chemical and biological properties of the soil have been analysed in the laboratory, distinguishing between basic and acid soils. Furthermore, a theoretical map of hypothetical future shrub-cleared areas and its potential to sequester carbon has been created.

Preliminary results showed  significant differences between post-land abandonment practices. Time since intervention has resulted a key factor in carbon dynamic evolution, and an increase in carbon storage and concentration with management has been recorded.

To sum up, management through shrub clearing has demonstrated to be an adequate strategy to offset carbon emissions to the atmosphere in soils of abandoned areas in the Mediterranean mid-mountains, offering socio-economic and ecological benefices while becoming an important tool against Global Change.

This research is part of the MANMOUNT project (PID2019-105983RB-100/AEI/ 10.13039/501100011033) funded by the MICINN. Melani Cortijos-López is working with an FPI contract (PRE2020-094509) from the Spanish Ministry of Economy and Competitiveness associated to the ESPAS project.
The silica gel dryer or the electrical heating. Which one is better to ameliorate humidity related anomalies using the MicroAeth AE-51?
Authors: Florczyk Grzegorz , Markowicz Krzysztof
Published: March 2022

Relative humidity and rates of its change are relevant parameters in atmospheric sciences. Observations of output data of AE-51 aethalometer operating in ACS1000 humidity chamber reveal a strong dependence of attenuation when rapid relative humidity changes are present. Data collected in winter 2020/21 and in autumn 2021 suggests a probability of similar effects occurring during UAV measurements as thermodynamic parameters could change fast during such runs. The effect is caused by an apparatus’ design preventing humid air to reach the part of the filter used as a reference. The measurement device compares the wet part of the filter to the dry reference part and produces sharp excursions in the output signal. These effects can be limited by introducing a drying unit as a part of an inlet. The presented study was aimed to compare a drying unit utilising a silica gel (passive drying) and a heated part of an inlet (active drying).
Improving the reliability of large-scale hydrological models with satellite observations
Authors: Vu Dung Trung , Dang Thanh Duc , Galelli Stefano
Published: March 2022

Over the past three decades, large-scale hydrological models have gained popularity due to the need to support water resources management at the regional and continental scales. One of the most challenging tasks for developing such models is the availability of data. The presence of human-water interactions, especially reservoir operations, can influence the model parameterization, while measured discharge and/or water levels along the rivers are necessary to the calibration purpose. However, such information is often unavailable. In particular, data on reservoir storage or river discharge are often not measured or shared between the riparian countries of transboundary rivers. A potential solution for this challenging task lies in satellite observations. Specifically, reservoir storage/release and river discharge/water level can be inferred from satellite images (Landsat/Sentinel-1/2) and/or altimetry data (Jason/Sentinel-3). In this study, we take advantage of remote-sensed data to improve the accuracy of a hydrological-water management model (VIC-Res) setup for the northern portion of the Mekong River Basin. Our modeling framework combines VIC-Res with an automated calibration procedure (based on a multi-objective evolutionary algorithm) that explicitly accounts for key water management decisions—inferred from satellite data—occurring within the basin. Results show that the use of such data largely improves the performance and reliability of the model.
Groundwater uptake dynamics of a lowland oak forest in the Great Hungarian Plain
Authors: Kiss Csaba László , Gribovszki Zoltán , Pinke Zsolt , Ács Tamás , Kozma Zsolt , Kalicz Péter
Published: March 2022

The groundwater uptake of forest stands often generates disputes, especially in today’s drying climate. Forestry in Hungary does not take into account groundwater as a surplus water resource under 2 meters, while other sources show forest groundwater uptake in case of much deeper water table. White method is the most appropriate way to quantify water consumption. It is based on the transpiration-caused diurnal fluctuation of groundwater.

Once in the Great Hungarian Plain, hardwood forests stood along the River Tisza. These riparian ecosystems were supplied significantly by river floods, directly or indirectly. These forests mostly disappeared because of land use changes and water regulation works. One of the relics is the Ohat Forest, a salt steppic oak forest on the edge of the Hungarian Puszta (Hortobágy). Historical maps prove that this area was continuously forested, even before the water regulations.

Because of its dryness, the 2020/21 hydrological year is especially suitable for water uptake analysis. Its yearly rainfall sum was 469.8 mm, compared to the long-term average (more than 500 mm). A groundwater well was settled in the forest on 28th of May 2021, and on 22nd of June 2021 a vented pressure transducer was installed to monitor the water table. Logged time series show diurnal groundwater fluctuation, by which we can estimate the environment-dependent groundwater uptake of the oak forest.

This research was supported by the NRDI Fund FK 20 Grant Project no. 134547 and TKP2021-NKTA-43 project at University of Sopron.
Tool for optimizing the scientific operations and performance of the Mars lander
Authors: Haukka Harri
Published: March 2022

For space projects, the availability of energy is a critical factor. The farther we go from the Sun the power of solar irradiance is weaker, at Mars it is 43 percent compared to the Earth. A special feature of Mars is the opacity of the atmosphere, as well as possible dust storms and sand floating in the atmosphere, which affect the solar irradiance received by the lander on the surface.

The most common methods for generating electrical energy in Mars are solar panels and a radioisotope thermoelectric generator (RTG). RGT produces energy all the time, regardless of the prevailing solar irradiance. For smaller landers, a combination of solar panels and batteries is usually sufficient. The possibility of using RTG as part of the energy production system has been considered in this work.

Payload and service electronics set the starting point for the design of the energy and power generation system. In addition to the electrical requirements, the mass and space limitations brought by the lander have to be taken account. The introduced tool was designed in the frame of the MetNet Mission and ESA MiniPINS study and both landers are relatively small and limitations are e.g. with the mass and volume of the batteries and available solar panels as well as the RTG. The optimization tool developed in this work provides virtually limitless possibilities to modify the energy system parameters, but due to the limitations imposed by the landers,  in this study we do not simulate unrealistic alternatives for the selected landers.

The introduced optimization tool was developed in two steps. First with MS Excel, which was used to define realistic starting points, e.g. the number of solar panels and batteries and testing the static operating modes at different solar irradiance densities and subsystem efficiencies. Second, we use a Python tool that includes all the features of the Excel tool and we can simulate the operations with variable solar irradiances at any time of the day and season with one minute resolution. The required solar irradiance data is acquired and extrated from the Mars Climate Database covering almost the whole Mars surface. The developed tool is designed to simulate operations more than one Martian year, so with the tool, user can cover and simulate all seasons in any location on the Mars.

Devices on the surface of Mars operate fully autonomously. In this case, the availability of energy and optimized use of it are key factors. The lander service electronics must be able to operate even in non-optimal situations and, if necessary, interrupt scientific operations. These operations are controlled by the so-called cyclograms, i.e. pre-programmed operation plans, implemented by the lander computer when required. In this work, we simulate cyclograms for different operating conditions using the developed optimization tool.
Soil fauna drives vertical redistribution of soil organic carbon by long-term irrigation in a dry pine forest
Authors: Guidi Claudia , Frey Beat , Brunner Ivano , Meusburger Katrin , Vogel Michael , Chen Xiaomei , Stucky Tobias , Gwiazdowicz Dariusz J. , Skubała Piotr , Schaub Marcus , Rigling Andreas , Hagedorn Frank
Published: March 2022

Summer droughts strongly affect soil organic carbon (SOC) cycling, but net effects on SOC storage are unclear as drought affects both C inputs and outputs from soils. Here, we explored the overlooked role of soil fauna on SOC storage in forests, hypothesizing that soil fauna is particularly drought-sensitive, thereby reducing litter incorporation into the mineral soil and, eventually, long-term SOC storage.

In a drought-prone pine forest (Switzerland), we performed a large-scale irrigation experiment for 17 years and assessed its impact on vertical SOC distribution and composition. We also examined litter decomposition of dominant tree species using litterbags of different mesh sizes and determined soil fauna abundance and community composition.

Long-term irrigation resulted in a C loss in the organic layers (-1.0 kg C m-2) and a comparable C gain in the mineral soil (+0.8 kg C m-2) in the first decade of irrigation, and thus did not affect total SOC stocks. Irrigation increased the mass loss of Quercus pubescens and Viburnum lantana leaf litter more strongly when meso- and macrofauna were included (+215%) compared to excluded (+44%). The enhanced faunal-mediated litter decomposition was paralleled by a many-fold increase in the abundance of meso- and macrofauna during irrigation. Moreover, irrigation led to a shift in Acari and Collembola community composition, with irrigation characterized by the presence of drought-sensitive species. In comparison, microbial SOC mineralization was less responsive to lower soil moisture. Our results suggest that the vertical redistribution of SOC with irrigation was mainly driven by litter incorporation through meso- and macrofauna, here accelerated by irrigation and suppressed by naturally occurring summer droughts.

Our study shows that soil fauna is highly sensitive to natural drought reducing the incorporation of C from organic layers to the mineral soil. In the longer term, this potentially affects SOC storage, decreasing the C stored in mineral soil. Therefore, soil fauna plays a key but so far largely overlooked role in shaping SOC responses to drought.

 
Validation and calibration of gas flow experiments with numerical simulations
Authors: Laddha Sunny , Macher Wolfgang , Zivithal Stephan , Kargl Günter
Published: March 2022

The success of the Rosetta mission to comet 67P/Churyumov–Gerasimenko has revolutionized our view of comets, while opening a plethora of new questions. In order to find the answers to them and harness the full potential of the new data, an international consortium named “Cophylab – Comet Physics Laboratory” (Cophylab.space) was launched in 2018. In this project several experiment campaigns were initialized to study cometary properties in a controlled environment. The idea was to isolate individual properties and processes in dedicated laboratory experiments. One of the experiment campaigns was designed to characterize gas flow properties of dry porous materials in a first step, with the aim of developing a model that improves our understanding of the outgassing of comets.

Before the initial model is extended to consider the sublimation of volatile components, it needs to be validated by alternative methods, such as numerical simulations. For this purpose, we chose the finite element method, to test the combination of the Darcy and Knudsen flow model, which was used in the preceding study.

Our approach was to use the results of the experiment as input in the simulations and compare the output with the measurements. This comparison confirmed the validity of the model and its assumptions. In particular, the sample is assumed to be homogenous and isotropic on a macroscopic scale, so that it can be described by a set of averaged parameters. While this description is relatively accurate for samples with well-defined grain shapes (e.g. spherical glass beads), significant discrepancies occur for inhomogeneous materials such as lunar, Asteroid or Martian analogues.

We investigated various aspects that were initially neglected in the evaluation of the measurements, such as channel building in the sample, boundary effects and non-ideal geometry of the experimental setup, which will be complemented by inhomogeneities that occur naturally in random close packing or ballistic deposition samples. Furthermore, we assessed the models range of applicability through a thorough review of the different flow regimes encountered in the measurements. Our findings indicate that boundary effects, as well as non-ideal geometry have a significant influence particularly in samples with larger grains. For finer grained samples on the other hand, inhomogeneities are the most probable cause for discrepancies. The grain size also plays an important role regarding the flow regime and its corresponding parameters.

The work for this study was performed in the framework of a master’s thesis, as part of the Cophylab project, which is funded by the D-A-CH program (DFG GU1620/3-1 and BL 298/26-1 / SNF 200021E 177964 / FWF I 3730-N36)
Weakly Constrained LETKF for Convective-Scale Data Assimilation
Authors: Janjic Tijana , Zeng Yuefei
Published: March 2022

Often physical properties of a system that we are modeling dictate plausible values of the initial conditions of our numerical models. Unfortunately, by using modern data assimilation techniques as the ensemble Kalman filter algorithm to obtain these initial conditions, physical property of non-negativity is frequently violated. To mitigate this sign problem and to simultaneously maintain the mass conservation, a new concept of combining weak constraints on mass conservation and non-negativity has been introduced in our recent paper (Janjic and Zeng 2021), with a focus on hydrometeor variables in convective-scale data assimilation. The algorithm is fast, easy to implement modification of the local ensemble transform Kalman filter that is able to weakly preserve both properties of mass conservation and non-negativity. In idealized experiments that assimilate radar data in non-hydrostatic, convection-permitting numerical model and update hydrometeor values, we show the benefit of the proposed approach on prediction of atmospheric water variables. Results show that both weak constraints successfully improve the mass conservation property in analyses and both reduce the biased increase in integrated mass-flux divergence and vorticity. Furthermore, the least biased increase is obtained by combining both constraints, and the best forecasts are also achieved by the combination.

Janjić, T., & Zeng, Y. (2021). Weakly constrained LETKF for estimation of hydrometeor variables in convective-scale data assimilation. Geophysical Research Letters, 48, e2021GL094962
Long-term forest soil warming decreases soil total P pools and negatively affects biotic P processes by promoting abiotic P sorption processes
Authors: Tian Ye , Shi Chupei , Urbina Malo Carolina , Kwatcho Kengdo Steve , Heinzle Jakob , Inselsbacher Erich , Ottner Franz , Borken Werner , Schindlbacher Andreas , Wanek Wolfgang
Published: March 2022

Phosphorus (P) is an essential element for all organisms, received increasing attention in global change research. Current P-related climate warming studies have mainly addressed warming effects on soil and plant P pools, but how soil P cycling processes respond to elevated temperatures has remained largely uncertain. In this study we investigated the effect of soil warming on both, soil P pools and P cycling processes (applying the 33P isotope pool dilution technique) across different soil depths (0-10 and 10-20 cm) and seasons (spring, summer, autumn) during the 15th year of soil warming (+4 °C) in a mature temperate mountain forest, in Achenkirch, Austria. Long-term warming decelerated the gross rates of phosphate (Pi) mobilization by 21%, reducing the soil Pi input. The decreased gross Pi mobilization was in part attributed to substantial losses of soil total P pools (substrates), which likely was caused by increased dissolved organic P leaching to deeper soil layers in the warming treatment. Abiotic immobilization increased in the warming treatment, due to increased sorption of Pi to iron oxyhydroxides and clay, further reducing soil Pi availability. Moreover, warming decreased biotic Pi immobilization and microbial biomass P, and as a response, microbial communities allocated more energy and nutrients into the production of acid phosphatase, indicating a strong shift in microbial carbon and nutrient allocation in response to the decreased P availability. According to linear mixed-effects models, most of the responses of the measured P pools and processes showed no interactions between warming and soil depth and/or season, indicating consistent effects of long-term soil warming on the P cycle across different soil depths and seasons. Overall, this study highlights for the first-time how long-term soil warming affects (biotic and abiotic) soil P processes and their interactions with soil P pools. Besides, it also indicates the potential of how P constraints can affect other biogeochemical cycles in response to warming.
A python interface for global geomagnetic field models: pymagglobal
Authors: Schanner Maximilian Arthus , Mauerberger Stefan , Korte Monika
Published: March 2022

We present pymagglobal, a simple to use python interface for global geomagnetic field models. Pymagglobal was developed to provide easy access to global, spherical harmonics based magnetic main field models over historical and paleomagnetic times. The software readily handles cubic-spline based geomagnetic field models stored in the same file format as gufm1 or the CALSxk model series out of the box. Models in other file formats can be incorporated with minimal effort using the python backend. The python interface can, e.g., give model curves for any location, time series of dipole moment or spherical harmonic coefficients or grids and maps of magnetic field components. 

Pymagglobal can be installed by a single command and comes with a command line interface and a GUI, that allows easy extraction and visualization of information from the models. Additionally, the python backend can be used to access the models, for example to generate synthetic data or refer to them in your own analysis. Emphasis is put on documentation and accessibility. The package is available via a git repository  and a custom website at https://git.gfz-potsdam.de/sec23/korte/pymagglobal.
Drivers of water footprints in crop production across different temporal and spatial scales
Authors: Zhuo La , Gao Jie , Wang Wei , Liu Yilin , Wu Pute
Published: March 2022

The water footprint (WF) of crop production indicates the water consumption for crop growth in a specific area over a certain time, enabling comprehensive water use efficiency assessments to be achieved for different types of water. Improved spatial and temporal resolutions in quantification enable the water footprint (WF) in crop production to be a comprehensive indicator of water consumption in agricultural water management. However, in time, although daily and monthly blue (irrigation water) and green (rainfall) water resources are unevenly distributed in monsoon climate areas, the crop WF are generally recorded by years. In space, there is a lack of quantitative research on the effects of different spatial levels on the variation in crop WFs. Meanwhile, effect of developments in water-saving irrigation techniques on large-scale crop WF accounting is unclear yet.

We conducted a series of case studies for China in order to address above three issues. In the first selected case for maize and wheat production in the Baojixia Irrigation District (BID) of Shaanxi province in the west China, the WF of crop production was analysed based on a regional distributed hydrological model and the associated meteorological driving factors on daily, monthly, and yearly scales were identified (Gao et al., 2021). The latter two case studies focused on wheat across the whole mainland China based on gridded crop WF simulations over the period 2000-2014. The WFs of wheat production at five different spatial levels, including crop field, county, river sub-basin, provincial, and large river basin were mapped followed by an analysis of meteorological and human management factors (Mao et al., 2021). The differences in terms of magnitudes, composition, and benchmarks of wheat WF under furrow, sprinkler and micro irrigation methods as well as rain-fed conditions were further distinguished and identified (Wang et al., 2019). Results revealed non-negligible effects of temporal and spatial scales on crop WFs. The possibility and importance to account for developments of water-saving techniques in regional crop WF estimations are shown as well.

 

References

Gao, J., Xie, P., Zhuo, L., Shang, K., Ji, X., Wu, P. (2021) Water footprints of irrigated crop production and meteorological driving factors at multiple temporal scales. Agricultural Water Management, 255: 107014.

Mao, Y., Liu, Y., Zhuo, L., Wang, W., Li, M., Feng, B. (2021) Quantitative evaluation of spatial scale effects on regional water footprint in crop production. Resources, Conservation & Recycling, 173: 105709.

Wang, W., Zhuo, L., Li, M., Liu, Y., Wu, P. (2019) The effect of development in water-saving irrigation techniques on spatial-temporal variations in crop water footprint and benchmarking. Journal of Hydrology, 577: 123916.