bluuebunny/crossref_metadata_2025 huggingface dataset:
ISMIP6-based projections of ocean-forced Antarctic ice loss using the Community Ice Sheet Model 
Authors: Lipscomb William , Leguy Gunter , Jourdain Nicolas , Asay-Davis Xylar , Seroussi Hélène , Nowicki Sophie
Published: March 2021

The future retreat rate for marine-based regions of the Antarctic Ice Sheet is one of the largest uncertainties in sea-level projections. The Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6) aims to improve projections and quantify uncertainties by running an ensemble of ice sheet models with forcing derived from global climate models. Here, the Community Ice Sheet Model (CISM) is used to run ISMIP6-based projections of ocean-forced Antarctic Ice Sheet evolution. Using several combinations of sub-ice-shelf melt schemes, CISM is spun up to steady state over many millennia. During the spin-up, basal-friction and thermal-forcing parameters are adjusted to optimize agreement with the observed ice thickness. The model is then run forward to year 2500, applying ocean thermal forcing anomalies from six climate models. In all simulations, ocean warming triggers long-term retreat of the West Antarctic Ice Sheet, especially in the Filchner-Ronne and Ross sectors. The ocean-forced sea-level rise in 2500 varies from about 150 mm to 1300 mm, depending on the melt scheme and ocean forcing applied. Further experiments show relatively high sensitivity to the basal friction law, and moderate sensitivity to grid resolution and the prescribed collapse of small ice shelves. The Amundsen sector exhibits threshold behavior, with modest retreat under many parameter settings, but complete collapse under some combinations of low basal friction and high thermal-forcing anomalies. Large uncertainties remain, as a result of parameterized sub-shelf melt rates, simplified treatments of calving and basal friction, and the lack of ice–ocean coupling.
Improved biodiversity from food to energy: Meta-analysis of land-use change to dedicated bioenergy crops
Authors: Donnison Caspar , Holland Robert , Harris Zoe , Eigenbrod Felix , Taylor Gail
Published: March 2021

Whilst dedicated bioenergy crops with non-food uses are currently sparsely deployed across the world, most future energy pathways necessitate a sizeable scale-up of 100-500 million ha of land converted to these crops to provide both energy substitutes for fossil fuels and negative emissions through bioenergy with carbon capture and storage (BECCS). In the face of expected bioenergy expansion, understanding the environmental and societal impact of this land-use change is important in determining where and how bioenergy crops should be deployed, and the trade-offs and co-benefits to the environment and society. Here we review the existing literature on two difficult to measure impacts which could prove critical to the future wide-scale acceptability of global bioenergy cropping in the temperate environment: biodiversity and amenity value. We focus on agricultural landscapes, since this is where large-scale bioenergy planting may be required. A meta-analysis of 42 studies on the biodiversity impacts of land-use change from either arable and grassland to bioenergy crops found strong benefits for bird abundance (+ 109 % ± 24 %), bird species richness (+ 100 % ± 31 %), arthropod abundance (+ 299 % ± 76 %), microbial biomass (+ 77 % ± 24 %), and plant species richness (+ 25 % ± 22 %) and a non-significant upward trend in earthworm abundance. Land-use change from arable land led to particularly strong benefits, providing an insight into how future land-use change to bioenergy crops could support biodiversity. Evidence concerning the impact of bioenergy crops on landscape amenity value highlighted the importance of landscape context, planting strategies, and landowner motivations in determining amenity values, with few generalizable conclusions. In this first meta-analysis to quanitfy the impacts of land-use change to bioenergy on on biodiversity and amenity,  we have demonsrated  improved farm-scale biodiversity on agricultural land but also demonstrated the lack of knowledge concerning public response to bioenergy crops which could prove crucial to the political feasibility of bioenergy policies such as BECCS.
Hierarchical Bayesian inference and spatial validation of socio-ecological system dynamics models: participatory modelling for Indigenous smallholder agriculture and food security in Guatemala
Authors: Malard Julien , Adamowski Jan , Tuy Héctor , Melgar-Quiñonez Hugo
Published: March 2021

Systems dynamics modelling is often used as a participatory modelling tool to model the long-term dynamics of socio-ecological systems, as well as to help in developing integrated policy decisions that take into account the unexpected and complex system behaviours that are often caused by the dynamic feedbacks between ecology and society. Actual use of these models in decision-making is, however, hindered by the frequent lack of high-quality temporal data on many key socioeconomic (and environmental) variables, which makes the application of traditional system dynamics model evaluation techniques difficult. This situation is particularly pronounced in the context of many Indigenous communities around the world, regions where improved access to decision support tools such as system dynamics modelling could be of particular use for supporting communities in their quest to make (and have implemented) their own resource management decisions. In the absence of rigorous quantification methods, however, these models are difficult to build and trust.

In this research, we present a novel methodology for calibrating hard-to-quantify relationships between socioeconomic variables of systems dynamics models. Based on hierarchical Bayesian inference, the methodology allows for the use of spatially explicit (but temporally poor) datasets to infer the quantitative, numerical relationships between socioeconomic variables, even when data in the precise region of interest is very scarce. We present, as a case study, a system dynamics model of small-scale agricultural systems and food security in two different regions of Guatemala (Tz'olöj Ya' and K'iche'), and analyse the impacts of different proposed policies in the face of socioeconomic shocks and water stress due to projected climate change. The hierarchical Bayesian inference calibration method allowed for the inference of key socioeconomic parameter values in a spatially explicit context to compensate for data scarcity, while spatial validation indicated which regions of the country the model was appropriate for.

Such a methodology, once incorporated into user-friendly system dynamics software, has the potential to facilitate participatory sociohydrological modelling even in quite data-scarce regions where modellers, up until now, have had to rely on educated guesses for the majority of the model's calibration.
Modelling Morphological Evolution of Deltaic Lobes in the Yellow River Mouth
Authors: Li Wei , Zhu Lehong , Hu Peng
Published: March 2021

In history, channel avulsion occurred frequently in the Yellow River Delta featuring by the combination of large-scale north-south shifts and small-scale evolution of “wandering-merging-meandering-diverting” patterns. However, these evolution processes are lack of quantitative investigations due to the complex interactions between riverine and tidal flows, and between sediment-laden flow and river bed as well. Since public observations are scarce, we numerically study this problem focusing on the controlling factors for reproducing the “wandering-merging-meandering” evolution patterns and the characteristics of relative morphological equilibrium under constant discharge and sediment conditions. Using a 2-D depth-averaged fully coupled morphological model, numerical experiments are carried out for a schematic Yellow River Delta. The results show that random disturbance on initial topography is the key factor to initiate wandering patterns. Moreover, the development of river patterns and the associated morphological time scales are strongly related to initial bed slopes and upstream discharge and sediment conditions. Generally, a small bed slope and a low discharge favor the formation of wandering patterns in the early stage, while a large bed slope and a high discharge may accelerate the merging and routing processes. In the case of upstream clear flow, channel formation is dominated by erosion processes. Yet with increasing sediment, it results from the combination of levee lip sedimentation and channel erosion. In addition, the flow routing may be facilitated by enhanced tidal ranges whereas decelerated when subaqueous sedimentation extends to the sea. Regarding the equilibrium state, the morphological time scales are 4~8 years in most cases and the width-depth ratio increases longitudinally following a power-law function.
HelioSwarm: Leveraging Multi-Point, Multi-Scale Spacecraft Observations to Characterize Turbulence
Authors: Klein Kristopher , Spence Harlan ,   HelioSwarm Science Team
Published: March 2021

There are many fundamental questions about the temporal and spatial structure of turbulence in space plasmas. Answering these questions is complicated by the multi-scale nature of the turbulent transfer of mass, momentum, and energy, with characteristic scales spanning many orders of magnitude. The solar wind is an ideal environment in which to measure turbulence, but multi-point observations with spacecraft separations spanning these scales are needed to simultaneously characterize structure and cross-scale couplings. In this work, we use synthetic multi-point spacecraft data extracted from numerical simulations to demonstrate the utility of multi-point, multi-scale measurements, in preparation for data from future multi-spacecraft observatories. We use the baseline orbit design for the HelioSwarm mission concept to explore the effects of different inter-spacecraft separations and geometries on the accuracy of reconstructed magnetic fields, cascade rates, and correlation functions using well-established analysis techniques.
Landward migration of backwater-mediated delta avulsion sites in response to increase in seasonal lake level: Qaidam Basin, China
Authors: Li Jiaguang , Ganti Vamsi , Wei Hao , Li Chenglong
Published: March 2021

River deltas grow through episodic channel-jumping events, called avulsions, which have caused some of the deadliest floods in human history. Climate change is threatening to drown river deltas through a global increase in sea level; however, it is unclear how sea-level rise may affect the location of avulsion sites. Theory and experiments indicate that the avulsion sites on lowland deltas emerge within the backwater zone of coastal rivers because of the morphodynamic feedbacks arising from natural flood discharge variability and the nonuniform flows caused by the standing water level in the receiving basin. Under this backwater hypothesis, marine transgression should cause the landward-migration of lobe-scale avulsion locations; however, we currently lack field evidence for this theoretical prediction. Here, we analyze the location of river avulsions on the Sulengguole River that drains into the North Hubusun Lake, Qaidam Basin, China. Using analysis of time-series satellite imagery, we identified 7 lobe-scale avulsions that occurred in the distal portions of the Sulengguole River during the observation period of 1985 to 2010 CE. Satellite imagery revealed that the areal extent of the seasonal water in the lake increased at a rate of 1.89±0.80 km2/yr, likely as a result of increase in extreme precipitation rates. The increase in seasonal lake water areas caused the river mouth of the Sulengguole River to translate landward at a rate of 0.36±0.17 km/yr. We show that the avulsion sites also migrated landward at a commensurate rate of 0.24±0.07 km/yr during this period, consistent with the rate of landward migration of the river mouth. Finally, we show that all 7 avulsions had an avulsion length—streamwise distance of the avulsion site to the river mouth—that scales with the estimated backwater lengthscale (mean of 0.50±0.14 times the backwater lengthscale), consistent with the global compilation of avulsion lengths on large, low-gradient deltas. Our work demonstrates, for the first time, that landward migration of river mouth that would result from relative sea-level rise will cause the avulsion locations to migrate inland in a predictable manner, with implications for the sustainable management of the future of deltas and mitigating flood hazards.
The delayed aftershocks of the Illapel Earthquake Mw 8.3, 2015, Chile
Authors: Lema Franco , Shrivastava Mahesh
Published: March 2021

The delayed aftershocks 2018 Mw 6.2 on April 10 and Mw 5.8 on Sept 1 and 2019 Mw 6.7 on January 20, Mw 6.4 on June 14, and Mw 6.2 on November 4, associated with the Mw 8.3 2015 Illapel Earthquake occurred in the ​​central Chile. The seismic source of this earthquake has been studied with the GPS, InSAR and tide gauge network. Although there are several studies performed to characterize the robust aftershocks and the variations in the field of deformation induced by the megathrust, but there are still aspects to be elucidated of the relationship between the transfer of stresses from the interface between plates towards delayed aftershocks with the crustal structures with seismogenic potential. Therefore, the principal objective of this study is to understand how the stress transfer induced by the 2015 Illapel earthquake of the heterogeneous rupture mechanism to intermediate-deep or crustal earthquakes. For this, coulomb stress changes from  finite fault model of the Illapel earthquake and with the biggest aftershocks in year 2015 are used. These cumulative stress pattern provides substantial evidences for the delayed aftershocks in this region. The subducting Challenger Fault Zone and Juan Fernandez Ridge heterogeneity are existing feature, which releases the accumulated coulomb stress changes and provide delayed aftershocks.  Therefore along with stress induced by a large earthquake such as Mw 8.3 from Illapel 2015 along with biggest aftershocks, have a direct mechanism that may activate the  delayed aftershocks. Our study suggests  the activation of crustal faults in this research as a risk assessment factor for the evaluating in the seismic context of the region and useful for another subduction zone.
Direct Numerical Simulation of an atmospheric-like differentially heated rotating annulus
Authors: Abide Stéphane , Meletti Gabriel , Isabelle Raspo , Viazzo Stéphane , Krebs Andreas , Randriamampianina Anthony , Harlander Uwe
Published: March 2021

Using high-order discretization on a High-Performance Computing framework, direct numerical simulations of a differentially heated rotating annulus are performed. The geometry of the baroclinic wave tank is similar to the new atmospheric-like experiment designed at BTU Cottbus-Senftenberg (Rodda et al., 2020), which also consists of a differentially heated rotating annulus. The experimental observations reveal  spontaneous emissions of inertial-gravity waves in the baroclinic wave jet front in accordance with Hien et al. (2018). The different length scales of inertial-gravity instabilities and the baroclinic waves make direct numerical simulation challenging. This motivates the current design of a new higher-order/HPC solver devoted to stratified rotating flows (Abide et al., 2018). Specifically, some features of compact scheme discretizations are used to combine efficiently parallel computing and accuracy for reducing DNS wall times. The ability to reproduce experimentally measured flow regimes with non-axisymmetric regular steady waves to the vacillation regimes is also discussed.

S. Abide et al. (2018), Comput Fluids 174:300-310.
S. Hien et al. (2018), J Fluid Mech 838:5–41.
C. Rodda et al. (2020), Exp Fluids 61:2.
High-fidelity ocean seismo-acoustic propagation modelling for signal interpretation at the CTBT IMS hydroacoustic stations
Authors: Nielsen Peter , Zampolli Mario , Le Bras Ronan , Haralabus Georgios , Heaney Kevin , Coelho Emanuel , Stevens Jeffry , Hanson Jeffrey
Published: March 2021

The Comprehensive Nuclear-Test-Ban Treaty’s (CTBT) International Monitoring System (IMS) is a world-wide network of stations and laboratories designed to detect nuclear explosions underground, in the oceans and in the atmosphere. The IMS incorporates four technologies: seismic, hydroacoustic and infrasound (collectively referred to as waveform technologies), and radionuclide (particulate and noble gas). The hydroacoustic component of the IMS consists of 6 hydroacoustic stations employing hydrophones suspended underwater near the axis of the Sound Fixing and Ranging (SOFAR) channel in the oceans and 5 near-shore seismic stations, called T-phase stations, located on islands or continental coastal regions. The T-phase stations are seismometers emplaced near the shore with the aim of detecting hydroacoustic signals that couple into the Earth’s crust near the coast. The main purpose of these hydroacoustic facilities is to detect nuclear test explosions in the oceans or near the surface of the oceans. Hydroacoustic signals propagate in the oceans very efficiently (little attenuation) and therefore the relatively small number of hydroacoustic stations suffice to cover most of the world’s oceans. However, interpretation of recorded signals even from known events can be difficult, since these signals propagate over very long distances. The ocean seismo-acoustic signals may on a global scale be affected by three-dimensional refraction, reflection and diffraction before arrival at a hydroacoustic station. In addition, ocean acoustic signals undergo a complex conversion to in-ground seismic signals when interacting with coastal regions that may modify signal features and evidence related to an explosion in the ocean before arrival at a T-station. The CTBTO has an ongoing effort to improve automatic detection, classification and localization of events, and to assist human analysts in interpreting these complex signals by incorporating knowledge obtained from high-fidelity seismo-acoustic modelling capabilities in the processing procedures. This presentation provides an overview of this project including justification of the choice of signal modelling approaches and validation of the models to fulfill accuracy criteria relevant for CTBTO. Examples of seismo-acoustic signal computations produced for inter-model comparisons and for assessing the relevance of such modelling capability to real operational scenarios are shown. Envisaged approaches for exploiting the complex modelling results and observations to improve the performance of the data processing are also presented.
Strateole-2: High-resolution observations of the tropical tropopause layer with long-duration balloons
Authors: Hertzog Albert , Plougonven Riwal ,   Stratéole-2
Published: March 2021

Strateole-2 is a project aimed at studying the coupling between the troposphere and the stratosphere in the deep tropics. The project originality pertains to the use of long-duration ballons, which can fly for several months at 18 or 20 km altitude. The first Strateole-2 campaign took place from November 2019 to February 2020: 8 balloons with various instrumental configurations were released in the lower stratosphere from Seychelles Islands, in the Indian Ocean.
This first campaign was primarily devoted to testing all systems (balloons, gondolas, and instruments) developed for the project, and was very successful: the balloons flew for 85 days onaverage over the whole tropical band, and most instruments performed nominally. In-situ meteorological measurements performed every 30-s on each flight provide a unique description of gravity-wave activity in the tropics and its relation to deep convection. The first observations of aerosols and water vapor onboard long-duration balloons were also achieved, which e.g. highlighted the tape recorder signal in the tropical lower stratosphere. Very innovative instruments also premiered during the campaign: RACHuTS, a light reeled payload, for instance performed 50 high-resolution vertical profiles of temperature, aerosols and water vapor down to 2km below the balloon, crossing several times the cold-point tropopause. ROC collected hundreds of temperature profiles down to the middle troposphere through GPS radio-occultations. Last, one balloon also carried a nadir-pointing backscatter lidar, which has described the underlying convection at unprecedented temporal resolution. An overview of the flights and first results will be presented.
Two forthcoming balloon campaigns are planned within Strateole-2, in 2021-22 and 2024-25. Each will release 20 balloons. 
Farmed calcite δ18O, δ13C, and Δ47 at Ascunsă cave, Romania
Authors: Dragusin Virgil , Ersek Vasile , Fernandez Alvaro , Ionete Roxana , Iordache Andreea , Meckler Nele , Mirea Ionut , Zgavarogea Ramona
Published: March 2021

Ascunsă cave (Romania) is the subject of a monitoring program since 2012. While the cave air temperature was very stable around 7°C for most of the time, it experienced in 2019 a 3°C rise, and remained high until the present.

We present here δ18O, δ13C, and clumped isotope results from calcite farmed at two drip points inside the cave (POM X and POM 2). POM X has a slower drip rate than POM 2 and deposits calcite more continuously. Calcite deposition has been shown to depend on cave air CO2 concentration, which controls the drip water pH and, further, the calcite saturation index.

In 2019, δ18O values at both sites quickly shifted to lower values as a response to the increase in temperature. At POM X, values were situated between approximately -7.2‰ and -7.6‰ before this transition, whereas in 2019 they shifted to -7.8‰ - -8.0‰. At POM 2, where values were generally lower, they shifted from -7.5‰ to -7.8‰ to -8.0‰.

Clumped isotope temperature estimates mostly agree, within measurement error, with measured cave temperature. This agreement is notable given that strong offsets are commonly observed in mid-latitude caves, reflecting kinetic fractionation effects. However, intervals with deviations from cave temperature are also observed, suggesting variations in isotopic disequilibrium conditions with time.

Here we will discuss these isotope changes in relation to cave air temperature and CO2 concentration, drip water isotope values and elemental chemistry, as well as in relation to drip rates, in order to improve our understanding of calcite precipitation and isotope effects in caves.
Kalmag: a high spatio temporal model of the Geomagnetic field
Authors: Baerenzung Julien , Holschneider Matthias
Published: March 2021

We present a new high resolution model of the Geomagnetic field spanning the last 121 years. The model derives from a large set of data taken by low orbiting satellites, ground based observatories, marine vessels, airplane and during land surveys. It is obtained by combining a Kalman filter to a smoothing algorithm. Seven different magnetic sources are taken into account. Three of them are of internal origin. These are the core, the lithospheric  and the induced / residual ionospheric fields. The other four sources are of external origin. They are composed by a close, a remote and a fluctuating magnetospheric fields as well as a source associated with field aligned currents. The dynamical evolution of each source is prescribed by an auto regressive process of either first or second order, except for the lithospheric field which is assumed to be static. The parameters of the processes were estimated through a machine learning algorithm with a sample of data taken by the low orbiting satellites of the CHAMP and Swarm missions. In this presentation we will mostly focus on the rapid variations of the core field, and the small scale lithospheric field.  We will also discuss the nature of model uncertainties and the limitiations they imply.
Soil plays a pivotal role in the distribution of plants, their traits and ecosystem functions in the French Alps
Authors: Martinez Almoyna Camille , Thuiller Wilfried , Foulquier Arnaud , Weil Sarah-Sophie , Münkemüller Tamara
Published: March 2021

Experiments and observations have shown that plants and soil biotic and abiotic properties are linked by feedback loops at local scale, in particular because plant functional traits determine the decomposability of the organic matter, which in turn influences the availability of nutrients essential for plant growth. However, the influence of plant-soil linkages on plant distributions and ecosystem functions is understudied at large biogeographic scales.

Here, I present results of studies along 18 elevational gradients in the French Alps. In a first study, I show how the distributions of 44 plant species does not only depend on climate but also on soil physico-chemical properties and microbial decomposition activity and that plant functional traits play an important role in these distributions. Using hierarchical effects and multi-species distribution models, we found that, in addition to climate, the combination of soil C/N, as a measure of organic matter quality, and exoenzymatic activity, as a measure of microbial decomposition activity, strongly improved predictions of plant distributions. In accordance with the ‘fast-slow’ plant economics spectrum, species with conservative traits performed better under limiting nutrient conditions but were outcompeted by exploitative plants in more favorable environments, resulting in a spatial segregation of plants with different ecological strategies. In a second study, we moved from species to community level to estimate the impact of these plant-soil linkages on ecosystem functions. Using an undirect partial correlation network revealed that the influence of plant traits on the quality of organic matter links aboveground and belowground ecosystem functions. Finally, I show how specific soil trophic groups, notably saprophytic fungi, play key roles in these linkages. This result highlights that decomposition and the organisms involved in this process are the corner stone of ecosystem multifunctionality in nutrient depleted ecosystems such as mountains. Together these results highlight the importance of considering plants and soil biodiversity along with abiotic predictors for better understanding and modelling ecosystem processes and functions in a world where both climatic and soil systems are undergoing profound and rapid transformations.
Dissimilar age and provenance of the Nindam and Jurutze volcaniclastic formations, Zanskar Gorge, Ladakh (India)
Authors: Andjic Goran , Zhou Renjie , Jonell Tara N. , Aitchison Jonathan C.
Published: March 2021

Pre-early Eocene volcaniclastic rocks exposed in the Indus Suture Zone (Ladakh, India) are key to deciphering the complex magmatic and tectonic evolution of the convergent margins that existed between India and Eurasia. Several hypotheses exist regarding the provenance of the middle Cretaceous to early Cenozoic Jurutze and Nindam formations yet there is presently no consensus. Leading models propose that: (a) they were either formed in neighbouring sub-basins at one convergent margin consisting of the Kohistan-Ladakh-Dras arc; or (b) they became stratigraphically superposed after the collision between the Kohistan-Ladakh and Dras arcs. Here we present new U-Pb detrital zircon, major and trace element geochemical, and petrographic datasets from the Nindam and Jurutze formations that support a disparate provenance and thus necessitate an alternative model. The Jurutze Fm. has a geochemical composition typical of arcs built on continental crust, whereas the Nindam Fm. presents a geochemical signature compatible with that of an intraoceanic arc. The significant age gap between these formations (>20 m.y.) in the Zanskar Gorge further precludes the possibility that the Jurutze Fm. was deposited on top of the Nindam Fm. We propose that the Nindam and Jurutze formations were deposited in distinct forearc basins and explore scenarios for their formation at separate convergent margins, i.e. the separate Kohistan-Ladakh and Dras arcs, respectively.
Developing an approach to calculate the WEI for the Austrian Rhine catchment
Authors: Broer Martine , Schönbauer Arnulf , Lindinger Helga , Brielmann Heike , Neunteufel Roman
Published: March 2021

Even though Austria is a water rich country, which uses approximately 3% of its water resources, regional and seasonal challenges to ensure the water supply might occur. To facilitate a long-term, sustainable strategy for water use, detailed information on available water resources and water demand as well as possible changes due to climate change are necessary. In the “Wasserschatz” project the current available groundwater resource and the water use for the following sectors: agriculture, public water supply, industry and selected services (technical snowing and golf courses) were elaborated.

For the Austrian part of the Rhine catchment, the Water Exploitation Index was calculated for the year 2016. Where applicable the abstraction data obtained in the “Wasserschatz” project were directly used in the WEI equation. The data for the WEI equation was obtained from very different data sources (measured data, estimated data, extrapolated data) a differentiated approach was needed for each type of data and for each sector.

A very important part of the WEI are the returns, for which a different method for each sector were developed (agriculture, public water supply, selected services, industry and energy). For agriculture it was assumed that water applied as irrigation was completely transpired into the atmosphere. For cattle, the abstraction data were calculated from the amount cattle, returns were estimated according to the milk production. The abstractions for the drinking water supply were obtained from a model developed by the Institute of Sanitary Engineering and Water Pollution Control at the University of Natural Resources and Life Sciences (Vienna), the returns are assumed to be a fixed factor from the abstractions.  For the Industry abstraction data were obtained from the water register(official notices) and from questionnaires (real abstraction data). The responses from the questionnaires were categorized according to company size and NACE codes and the data was extrapolated to other companies. For the returns either data from the water register was used or factors from literature were used.

To obtain the renewable resources the calculated outflow of the Rhine catchment was used. The water use in the WEI is described as the abstractions – returns, where all the water that stays in the catchment is considered a return. For a water rich catchment as the Rhine, the WEI is expected to be very low. In a future step the WEI index for the Austrian part of the Danube will also be calculated. Another planned improvement is to disaggregate the available data and calculate a seasonal WEI+.
Numerical simulation study of sea spray’s effect on tropical cyclone——a case study of typhoon “Megi”
Authors: Zhang Jialin , Zhang Wenqing , Xia Haofeng , Guan Changlong
Published: March 2021

Sea spray has important influence on the evolution of tropical cyclone. The influence of sea spray in the numerical simulation and prediction of tropical cyclones is not ignorable. In order to explore the kinetic and thermodynamic effects of sea spray on tropical cyclone, the drag coefficient CD and the enthalpy transfer coefficient CK with sea spray’s effects were included in the coupled ocean-atmosphere-wave-sediment transport modeling system (COAWST). The numerical results show that, the effect of sea spray can effectively improve the simulation results of tropical cyclone path. When only the kinetic effect of sea spray is considered, the momentum flux at the surface of sea is little affected, and the upward sensible heat flux and latent heat flux are slightly increased. When kinetic and thermodynamic effects of sea spray is considered at the same time, the momentum flux is slightly increased, the upward sensible heat flux is increased, and the latent heat flux is significantly increased, the intensity of tropical cyclone is significantly enhanced, mainly due to the thermodynamic effect . Considering the kinetic and thermodynamic effects of sea spray at the same time is more effective than considering the kinetic effects of sea spray in improving the intensity simulation of tropical cyclone.
The evolution mechanisms of Ural blocking from the lens of local finite-amplitude wave activity budget analysis 
Authors: Wang Mengling , Zhang Yang , Lu Jian
Published: March 2021

Understanding the formation and evolution mechanisms of Ural blocking (UB) is of great importance for the prediction of UB and relevant extremes in east Asia. Using the 6-hourly ERA-Interim reanalysis data, this study quantifies the conservative and nonconservative processes in the lifecycle of UB through the lens of the hybrid Eulerian-Lagrangian local finite-amplitude wave activity (LWA) diagnostics. It is found that (i) as a wave activity source, eddy heat flux works to not only initiate the UB, but also prevent the wave activity of the blocking from dispersing downstream---the key characteristic of blocking; (ii) both the wave propagation and wave advection mechanisms are indispensable for the evolution of UB, playing a tug-of-war on the downstream development of wave activity; (iii) throughout the lifespan of UB, diabatic heating provides the most important damping mechanism for the wave activity both upstream and downstream.
Modelling biomass and biodiversity in temperate grasslands with Sentinel-1, Sentinel-2 and Unmanned Aerial Vehicles.
Authors: Muro Javier , Schwarz Lisa , Männer Florian , Linstädter Anja , Dubovyk Olena
Published: March 2021

Land use practices in grasslands are major determinants of their biodiversity and ecosystem functions. Relationships between biodiversity, ecosystem functions and land use practices can vary across climatic and management gradients and across scales. New generations of remote sensing sensors can model grasslands’ biomass and biodiversity parameters with relative RMSE that range between 10% and 40%. However, most of these experiments have been carried out in rather small and homogenous areas. In the project SeBAS (Sensing Biodiversity Across Scales) we are using machine learning algorithms (random forest and neural networks) to model biomass and biodiversity indicators along spatial and management gradients and across scales. Field data (above ground biomass and species inventories) was obtained during summer 2020 from the Biodiversity Exploratories: a set of 150 grassland plots across spatial and management gradients in Germany. Remote sensing information at farm level was obtained from microwave Sentinel-1 and multispectral Sentinel-2 satellites, and at plot level from a multispectral camera mounted on a UAV.

First results show the limitations of satellite images to map vegetation parameters in heterogeneous landscapes, and how the incorporation of UAV information can be used to improve model estimations of biomass production and biodiversity indicators.
Next generation of Automated Low Investment Cost Evaporometers (ALICE)
Authors: Tejkl Adam , Kavka Petr
Published: March 2021

Research of evaporation height is curtailing for measuring of the water balance in small catchments and for proper and efficient running of irrigation systems.

Ongoing project to develop the simple and reliable, easy to reproduce evaporation measuring device. Core part of the device are measuring of the water level in field in cheap form. 3D printed design in combination with open-source cheap electronics is utilised. Methodology and results of the ongoing research project will be presented. Project investigates the affordable and simple technical measures that have a potential to increase the number of opportunities for the measuring of evaporation.

Continuously the theories are developed and tested, subsequently conclusions are implemented into the next generation of the device. Seven generations of 3D printed part have been done, and now the research focus on the water supply part of the device. Durability and reliability of the device is tested in field, in three locations. All plots are monthly checked by research staff and data is saved and later compared with data measured by device. Refilling of the evaporation pan is done automatically.

Prototype seven uses the experience of all previous prototypes. The construction is equipped with 50 individual electrodes, each electrode is 1 mm shorter than previous. Another 2 electrodes serve as a negative collector. The total measuring range is 50 mm. The whole structural part of prototype seven is designed as a printout on a 3D printer, electrodes are printed from conductive material. Above the electrodes there is a printed circuit board carrying the microelectronics control.

The principle of measurement consists in measuring of capacity of capacitors joined in parallel. Charge goes through the capacitors to needles, then through water environment to negative collector needle and to negative terminal. Because different lengths of the needles, change of water depth, changes the number of submerged needles and thus number of connected capacitors. So, water depth is directly related to measured capacity.

A commonly used evaporation unit is mm of water column per day. It is therefore necessary to analyze a long time series, at least longer than one day, and covering the entire day from 00:00 to 23:59. On the other hand, there is need for redundant data, so measuring step six hours is chosen.

The sites are the grounds of the CTU Faculty of Civil Engineering in Dejvice, the experimental sites of the CULS in Prague Suchdol and the Water Research Institute in Prague Podbaba.

The research is funded by the Technological Agency of the Czech Republic (research project TJ02000351 - Development of Tools and Methods Improving Estimation of annual Evaporation Balance).
A mechanism predicting the climate response to sea ice loss from its geometry
Authors: Levine Xavier , Cvijanovic Ivana , Ortega Pablo , Donat Markus , Tourigny Etienne
Published: March 2021

As climate warms sea ice loss may become a potent climate change feedback, both in the Arctic and at lower latitudes. For instance, extreme events over Europe and North America, such as drought or warm spells, have been attributed to sea ice minima in recent years. Yet a comprehensive understanding of the local or remote impact of sea ice loss on climate is lacking, with the predicted atmospheric and oceanic response to sea ice loss differing between climate studies. In particular, the impact of varying geographical distribution of sea ice loss on regional climatic changes remains uncertain.

Here, we assess the sensitivity of the atmospheric response to various patterns of sea ice loss, at a pan-Arctic or regional scale, by analyzing a set of idealised AMIP-like simulations. Depending on where sea ice is reduced, we find that climatic anomalies can vary widely among experiments, especially the zonal-mean component of the tropospheric circulation: for instance, the subpolar jet and polar cell can strengthen or weaken with sea ice loss, depending on its geographical distribution. We demonstrate that the geometry of the sea ice loss, in particular the degree to which sea ice extent changes is zonally symmetric or asymmetric, controls this disparate climatic response through an atmospheric feedback mechanism. In this feedback mechanism, changes in poleward eddy heat flux and latent heat release over the Arctic in response to a specific sea ice loss pattern can either warm or cool the Arctic troposphere. We discuss the implications of our results for interpreting the apparent discrepancies in the climate response to Arctic sea ice variability among studies.
The First Holocene Varve Chronology for the UK: based on the integration of varve counting, radiocarbon dating and tephrostratigraphy from Diss Mere (UK).
Authors: Martin-Puertas Celia , Walsh Amy A. , Blockley Simon P.E , Harding Poppy , Biddulph George E. , Adrian Palmer , Arne Ramisch , Achim Brauer
Published: March 2021

This paper reports the first Holocene varved chronology for the lacustrine sediment record of Diss Mere in the UK. The record of Diss Mere is 15 m long, and shows 4.2 m of finely-laminated sediments, which are present between ca. 9 and 13 m of core depth. The microfacies analysis identified three major seasonal patterns of deposition, which corroborate the annual nature of sedimentation throughout the whole interval. The sediments are diatomaceous organic and carbonate varves with an average thickness of 0.45 mm. A total of 8473 varves were counted with maximum counting error of up to  40 varves by the bottom of the varved sequence. To tie the resulting floating varve chronology to the IntCal 2020 radiocarbon timescale, we used a Bayesian Deposition model (P_Sequencewith outlier detection) on all available chronological data from the core. The data included five radiocarbon dates, two known tephra layers (Glen Garry and OMH-185) with calendar ages based on Bayesian modelling of sequences of radiocarbon ages, and the relative varve counts between dated points. The resulting age-depth model (DISSV-2020) dates the varved sequence between ca. 2100 and 10,300 cal BP and age uncertainties are decadal in scale (95% confidence). 
Snow as a source of predictability in seasonal forecasts?
Authors: Risto Danny , Ahrens Bodo , Fröhlich Kristina
Published: March 2021

Besides the ocean, the land surface is a crucial component for predictability at (sub-)seasonal time scales. While the prediction of 2m temperature up to several months is possible for some maritime regions, continental regions lack predictive skill. Improved representation of the land surface in seasonal forecasting systems could help to close this gap. Snow cover fraction and snow water equivalent (SWE) are essential properties of the land surface. A snow-covered land surface leads to local temperature decreases in the overlying air (snow-albedo effect and high emissivity) and melting snow cools the surface air and contributes to soil moisture. First, we analyse the dynamical relationships between snow, 2m temperature and sensible/latent heat fluxes in reanalysis data in the northern hemisphere. Then we investigate whether these relationships are also present in operational seasonal forecast models provided by Copernicus Climate Change Service (C3S). First results show that the quality of the 2m temperature forecast over continental regions drops sharply after the first forecasted month, whereas anomalies in snow water equivalent can be predicted up to several months. Forecasted anomalies in sensible and latent heat fluxes of continental land surfaces show predictive skill during winter and spring only locally in some places, which reduces potential interactions between snow/land surface and the atmosphere in the models. The goal of this ongoing work is to assess the importance of snow initialisation and parameterisation for seasonal forecasting.
Monitoring the effectiveness of connected ponds at fine sediment and phosphorus retention in a lowland agricultural stream
Authors: Robotham John , Old Gareth , Rameshwaran Ponnambalam , Sear David , Gasca-Tucker David , Soteriou Helena , Bishop James , Berkeley Ann , McKnight David , Old Joanne
Published: March 2021

Agricultural land is a key source of fine sediment and nutrients, often contributing significantly to diffuse pollution and catchment water quality issues. In the UK, recent efforts to mitigate agricultural diffuse pollution and reverse declines in the chemical and ecological status of waterbodies have focussed on catchment-based approaches. These nature-based solutions involve restoring, enhancing, or emulating natural processes to slow, store, and filter water and contaminants as they move through a catchment. Several studies in UK catchments show the potential benefits of retention ponds and constructed wetlands, however their functioning has been shown to vary according to their design and the catchment typology they are situated within.

To help further the evidence base on the effectiveness of ponds for mitigating diffuse agricultural pollution, we monitored a series of small, connected pond features (draining 0.3 km2 of slowly permeable clay soils) created as part of the Littlestock Brook Natural Flood Management (NFM) scheme. This lowland NFM scheme, situated in the headwaters of the River Thames basin (South East England), targets the issues of flooding and diffuse pollution, and is delivered through the Evenlode Catchment Partnership and Environment Agency as part of a five-year project (2016-2021).

Water and sediment sampling were undertaken during both baseflows and stormflows to determine retention of sediment and phosphorus species within the ponds under varying hydrological conditions. Results demonstrate that during small to moderate storm events, the ponds were able to capture run-off and reduce peak concentrations of suspended solids and particulate phosphorus. However, during large magnitude events, the ponds became inundated and resuspension of previously deposited sediment caused a net loss of material from the system. We estimate that the annual settling flux within the pond series is 16.48 tonnes (±5.77) for sediment, and ~0.014 tonnes for phosphorus. This equates to 17% (±6) of the annual suspended sediment load for the wider 3.4 km2 sub-catchment area. This study highlights the complexities of sediment dynamics in connected pond features and the importance of maintenance for retention efficiency.
Plastic mulch in agriculture: the case of low density polyethylene and its interactions with pesticides and soil microbiota
Authors: Beriot Nicolas , Zornoza Raul , Zomer Paul , Ozbolat Onurcan , Lloret Eva , Ortega Raúl , Miralles Isabel , Huerta Lwanga Esperanza , Geissen Violette
Published: March 2021

Low Density Polyethylene is the most applied plastic mulch in agriculture, for decreasing water evaporation, increasing soil temperature, or preventing weeds. Incomplete removal of polyethylene mulch causes plastic pollution in agricultural soils. In conventional agriculture the use of plastic mulch is combined with the use of pesticides. Little is known about the long term effects on soils of plastic debris accumulations in relation with pesticides residues.

We studied 18 parcels in vegetable farms, under organic or conventional management, where plastic mulch has been used for 5 to 20 years in Cartagena’s country side (SE Spain). We sampled soil at two depths: 0-10 cm and 10-30 cm. We compared the macro and micro plastic debris contents, the pesticides residue levels and the soil physiochemical properties between parcels. The ribosomal 16S and ITS DNA regions were sequenced to study shifts in bacterial and fungal communities, respectively. Soils under conventional management contained on average more than 6 different pesticides residues and soils in both managements contained on average 0.2±0.26 g/kg plastic debris. This study also showed how plastic and pesticides interact in soils and affect the microbial community. We identified the most sensitive groups which can act as bioindicators for plastic and pesticide pollution in soils.