bluuebunny/crossref_metadata_2025 huggingface dataset:
On the utility of flux rope models for CME magnetic structure below 30Rs
Authors: Lynch Benjamin , Al-Haddad Nada , Yu Wenyuan , Palmerio Erika , Lugaz Noé
Published: March 2022

We present a comprehensive analysis of the three-dimensional magnetic flux rope structure generated during the Lynch et al. (2019, ApJ 880, 97) magnetohydrodynamic (MHD) simulation of a global-scale, 360 degree-wide streamer blowout coronal mass ejection (CME) eruption. We create both fixed and moving synthetic spacecraft to generate time series of the MHD variables through different regions of the flux rope CME. Our moving spacecraft trajectories are derived from the spatial coordinates of Parker Solar Probe’s past Encounters 7 and 9 and future Encounter 23. Each synthetic time series through the simulation flux rope ejecta is fit with three different in-situ flux rope models commonly used to characterize the large-scale, coherent magnetic field rotations observed in a significant subset of interplanetary CMEs (ICMEs). We present each of the in-situ flux rope model fits to the simulation data and discuss the similarities and differences in the model flux rope spatial orientations, field strengths, and magnetic flux content. We compare in-situ model properties to those calculated with the MHD data for both classic bipolar and unipolar ICME flux rope configurations as well as more problematic profiles such as those with a significant radial component to the flux rope axis orientation or profiles obtained with large impact parameters. We find general agreement among the in-situ flux rope fitting results for the classic profiles and much more variation among results for the problematic profiles. We also present a comparison between the MHD simulation data and the in-situ model flux ropes in a hodogram representation of the magnetic field rotation. We conclude that the in-situ flux rope models are generally a decent approximation to the field structure, but all the caveats associated with in-situ flux rope models will still apply (and perhaps moreso) at distances below 30Rs. We discuss our results in the context of future PSP observations of CMEs in the extended corona.
An exploration of Bayesian identification of dominant hydrological mechanisms in ungauged catchments
Authors: Prieto Cristina , Le Vine Nataliya , Kavetski Dmitri , Fenicia Fabrizio , Scheidegger Andreas , Vitolo Claudia
Published: March 2022

Hydrological modelling of ungauged catchments, which lack observed streamflow data, is an important practical goal in hydrological sciences. A major challenge is to identify a model structure that reflects the hydrological processes relevant to the catchment of interest.

This study contributes a Bayesian framework for identifying individual model mechanisms (process representations) from flow indices regionalized to the catchment of interest. We extend a method previously introduced for mechanism identification in gauged basins, by formulating the inference equations in the space of (regionalized) flow indices and by accounting for posterior parameter uncertainty. A flexible hydrological model is used to generate candidate mechanisms and model structures, followed by statistical hypothesis testing to identify "dominant" (more a posterior probable) model mechanisms.

The proposed method is illustrated using real data and synthetic experiments based on 92 catchments from northern Spain, from which 16 catchments
are treated as ungauged. 624 hydrological model structures from the flexible framework FUSE are employed.

In real data experiments, the method identifies a dominant mechanism in 27% of 112 trials (processes and catchments). The most identifiable process is routing, whereas the least identifiable processes are percolation and unsaturated zone processes. In synthetic experiments, where "true" mechanisms are known, the reliability of method varies from 60% to 95% depending on the combined regionalization and hydrological error; the probability of making an identification remains stable at around 25%. More broadly, the study contributes perspectives on hydrological mechanism identification under data-scarce conditions; limitations and opportunities for improvement are outlined.
Coastal evolution in Southern Thailand between 1990 and 2018: an application of the CoastSat toolkit.
Authors: Curoy Jerome , Ward Raymond , Barlow John , Moses Cherith , Nakhapakorn Kanchana
Published: March 2022

Coastal areas in Thailand are largely under threat from flooding as a result of a range of factors including coastal erosion, coastal land subsidence, sea level rise and climate change. The erosion of coastal areas in Thailand has been a huge concern to national and local authorities as 17% of the Thai population (approximately 11 million people) live on the coastal plains and a large part of the Thai economy revolves around the exploitation of coastal resources via tourism, fishing or farming.

A recent study estimated a mangrove forest loss of just over 45% between 1961 and 1996 (Sampantamit et al., 2020), while measurements of the shoreline evolution in 2011 by the Thai Department of Marine and Coastal Resources (DMCR) revealed high rates of erosion (>5m per year) along long stretches of sandy beaches of Southern Thailand. As a response to those emergencies, Thailand has invested a lot of money in protecting and restoring their coastal mangroves since the mid-90s, and more recently financed large realignment or replenishment plans for their beaches.

This study assessed the long-term state of coastal evolution of both the Krabi and Nakhon Si Thammarat coastlines (560 km of coastline approximately) in southern Thailand. This was undertaken using the toolkit Coastsat to digitise a time series of shoreline positions from freely available satellite images between 1990 and 2019. . Based on these digitised shorelines and the use of the software DSAS, it was possible to identify shoreline change, which varied between -66 to +16.4 m/y in the mangroves of Nakhon Si Thammarat and -22.2 to +10.6 m/y on its sandy beaches. Shoreline change rates along the Krabi coast varied -34.5 to +21.7 m/year in the mangroves and -4.1 to +4 m/y on sandy beaches.

The analysis of the spatial and temporal variations of the shoreline position during the survey period reveals, in some places along the Nakhon Si Thammarat coastline, how efficient coastal defence work has been. This work also revealed the synchronicity between large and sudden coastal erosional movements and the occurrence of typhoons or tropical storms coming from the Sea of China, highlighting the importance of extreme weather events on sediment remobilisation on the Eastern coast of Southern Thailand.

This work also supports the use of freely available semi-automated toolkits such as CoastSat to deliver crucial and reliable time series shoreline data over extensive areas. The relevance of those newly developed tools is emphasised by the current COVID 19 travel bans and restrictions, which limit travel abroad for coastal managers and researchers to. The ability to collect, visualise and analyse remotely large datasets of environmental data has been essential over the last two years.
Improving confidence in model-based Probable Maximum Precipitation : Assessing sources of model uncertainty in storm reconstruction and maximization 
Authors: Tarouilly Emilie , Cannon Forest , Lettenmaier Dennis
Published: March 2022

We present an analysis of uncertainty in model-based Probable Maximum Precipitation (PMP) estimates. The focus of the study is on “model-based” PMP derived from WRF (Weather Research and Forecasting) model reconstructions of severe historical storms and amplified by the addition of moisture in the boundary conditions (so-called Relative Humidity Maximization technique). Model-based PMP offers numerous advantages over the currently-used approach that is described in NOAA Hydrometeorological Reports. By scaling moisture and producing the resulting precipitation according to model formulation, the model-based approach circumvents the need for linearly scaling precipitation. Despite the significant improvement this represents, model-based PMP retains some degree of uncertainty that precludes its use in operational settings until the uncertainty is rigorously evaluated. This paper presents an ensemble of PMP simulations that samples recognized sources of uncertainty: (1) initial/boundary condition error, (2) choice of physics parametrizations and (3) model error due to unresolved subgrid processes. To our knowledge, this is the first uncertainty analysis conducted for model-based PMP. We applied this ensemble approach to the Feather River watershed (Oroville dam) in California. We first carried out in-depth evaluation of model reconstructions and found that the performance of some storm reconstructions that underlie the PMP estimate is not ideal, though the lack of uncertainty information about observations currently prevents us from identifying “well-reconstructed” storms or performing bias correction. That being said, our ensemble indicates that the 72-hour maximized precipitation totals used for PMP estimation do not differ greatly (110% at most) from the single-value estimate when model uncertainty is considered. We emphasize that model-based PMP estimates should always be presented as a range of values that reflects the uncertainties that exist, but concerns about model uncertainty should not hinder the development of model-based PMP.
Biogenic polymers aggregation drives the export and vertical dynamics of small microplastics in the North Atlantic Gyre 
Authors: Galgani Luisa , Schulz-Böttcher Barbara , Gossman Isabel , Liu Zhanfei , Jiang Xiangtao , Scheidemann Lindsay , Schlundt Cathleen , Engel Anja
Published: March 2022

One of the major knowledge gaps in the study of plastic pollution is the understanding of residence times of these anthropogenic particles once they reach our oceans. Observations report a mismatch between estimates of plastic loads from worldwide plastic production and mismanaged plastic waste and actual plastic concentration seen floating at the sea-surface. Surveys of the water column -from the surface to the deep sea- are rare. Most of the recent efforts have thus addressed this question with modeling approaches or laboratory experiments that individuate in biofouling an important factor for the removal efficiency of plastics at sea and a likely explanation for the “missing plastic”. For the first time, we provide in-situ measured fluxes and removal rates of microplastics using deployments of drifting sediment traps in the North Atlantic Gyre from 50 m down to 600 m depth. We identified and quantified plastic contents with two different analytical approaches, FTIR and Py-GC/MS to determine polymer mass and particle distribution over depth.  From derived data, interaction with biogenic polymers and thus particles transfer from the surface to the deep ocean are reconstructed. These findings shed a light on important pathways that regulate microplastics fate in marine ecosystems, from possible harmful repercussions on marine biota to impacts on fundamentals elements cycles.
Coordinating systems headroom for more efficient multi-catchment water quality management at a critical checkpoint 
Authors: Liu Leyang , Dobson Barnaby , Mijic Ana
Published: March 2022

Managing river water quality at critical checkpoints that have significant impacts on water use is important for sustainable catchment development. This requires managing the whole multi-catchment systems upstream of a critical checkpoint. Concepts of systems headroom (deficit below permit) and excess (extra above permit) have been used to distinguish sub-catchments’ roles in pollution contribution. Based on the concepts, we propose a three-phase management approach. In the first phase, we frame the headroom and excess at temporal, spatial, and source domains and evaluate them to investigate the systems mechanisms. The evaluation is by simulating physical processes a semi-distributed integrated model (CatchWat-SD). We apply the model to 12 sub-catchments that make up the Upper Thames river basin and validate it using monitoring data. In the second phase, we incorporate the evaluated headroom and excess in loads allocation to develop a strategy that coordinates systems headroom for more efficient and realistic interventions. In the last phase, we validate the strategies by simulating the scenarios that coordinate headroom at different domains and evaluating them in water quality improvement, efficiency, temporal steadiness, spatial homogeneity, and practical feasibility. Results show that dry seasons, downstream catchments and urban sources generally have more excess. Thus, more target loads reduction is allocated to dry season, downstream catchments and urban sources in the fully coordinated scenario. The higher degree of headroom coordination a strategy achieves, the better performance this strategy generally obtains in all five metrics. This study emphasises the need to incorporate headroom in loads reduction allocation, which helps to more efficiently improve systems water quality performance with a more realistic degree of intervention. The whole procedure can be further expanded to water quality management at multiple checkpoints for sustainable management in large catchments.
The framework for improving air quality monitoring over Indian cities
Authors: Roy Arindam , Nenes Athanasios , Takahama Satoshi
Published: March 2022

Indian air quality monitoring guideline is directly adopted from World Health Organization (1977) guidelines without place-based modification. According to Indian air quality guidelines (2003), the location of monitoring sites should be determined from air quality modeling and previous air quality information. If such information is not available, the use of emission densities, wind data, land-use patterns and population information is recommended for prioritizing areas for air quality monitoring. The mixed land-use distribution over Indian cities and randomly distributed sources pose serious challenges, as Indian cities (unlike in other parts of the world) are characterized by a lack of distinct residential, commercial, and industrial regions, so the concept of “homogeneous emissions” (which have guided site monitoring decisions) simply does not apply. In addition, the decision-making data emission and population information, are either not available or outdated for Indian cities. Unlike the cities in Global North, the Indian urban-scape has distinguished features in terms of land use, source and population distribution which has not been addressed in air quality guidelines.

We have developed an implementable place-based framework to address the above problem of establishing effective new air quality stations in India and other regions with complex land-use patterns. Four Indian million-plus cities were selected for the present study; Lucknow, Pune, Nashik and Kanpur. We broadly classified air quality monitoring objectives into three; monitoring population exposure, measurements for compliance with the national standards and characterization of sources. Each monitoring station over four cities was evaluated and metadata has been created for each station to identify its monitoring objective for each of the stations. We find that present air quality monitoring networks are highly inadequate in characterizing average population exposure throughout each city, as current stations are predominantly located at the site of pedestrian exposure, and are not representative of the city-wide exposure.

Possible new sites for monitoring were identified using night-time light data, satellite-derived PM2.5, existing emission inventories, land-use patterns and other ancillary open-sourced data. Over Lucknow, Pune and Nashik, setting up stations at highly populated areas is recommended to fulfill the knowledge gaps on the average population exposure. Over Kanpur, it was recommended to incorporate stations to measure short-term pollution exposure in traffic and industrial sites. Rapidly developing peri-urban regions were identified using night-time light data and recommendations were provided for setting up monitoring stations in these regions.
Analysis of methodologies to evaluate the environmental impacts of solid waste management in the city of Bogotá
Authors: Becerra Quiroz Ana Paola , Solano Meza Johanna Karina , Rodrigo Ilarri Javier , Rodrigo Clavero María Elena
Published: March 2022

Solid waste management produced in megacities is usually being transformed under a linear treatment scheme which considers the circular economy model guidelines (waste reduction, reuse and recycling). The comprehensive solid waste management plan (PGIRS 2020) proposed for the city of Bogotá (Colombia) implements this circular economy approach through different strategies, such as increasing the separation levels at the source, optimizing collection and recycling, including waste as raw materials in production processes and designing technological alternatives different from landfills for the use and treatment of solid waste. Under this new vision, the design of waste management systems must consider those environmental impacts generated throughout the life cycle of waste while integrating ways to address these impacts in comprehensive waste management plans. Furthermore, health and environmental impacts that will result from new forms of waste use or mismanagement must be considered, including the mitigation of climate change effects by diverting waste that would potentially go to a landfill. Therefore, the methodologies adopted to evaluate environmental impacts must be aligned with these new trends while being capable of providing the required and appropriate results for decision-making to achieve established goals.

This work shows the methodologies used to evaluate the environmental impacts generated by solid waste in Bogotá. These methodologies have generally been qualitative so far: checklists, double-entry matrices, indicators and problem trees. They have been selected based on the availability of information, ease of calculation and the physical and technical availability of infrastructures. While different phases of solid waste management may require different methodologies, progress must be made in using more precise methods to reduce uncertainty in the evaluation and become more effective decision-making tools. One of these tools is the Life Cycle Analysis methodology (LCA). LCA provides an opportunity to make progress in including the circular economy approach in the comprehensive solid waste management of the city of Bogotá.
A Systems Dependency Framework for Individual, Multi- and Systemic Risks
Authors: Hochreiner-Stigler Stefan , Sakic Trogrlic Robert
Published: March 2022

ABSTRACT: New approaches for the assessment and management of individual, multi- and systemic risks are needed. In this work, we present a framework for the assessment and management of these risks based on the system dependency perspective. We suggest that dependencies may act as one guiding principle not only for assessing such risks but also for evaluating risk management options. The two most extreme cases within the suggested systems dependency perspective are the independence and full dependency state, representing the two ends of the risk continuum. Such a perspective enables an integration of risk management strategies within a coherent framework across geographical and governance scales (i.e., from local to global). Furthermore, individual and multi-hazard risks can be tackled simultaneously as well as independently through the assumption of different strengths of connectedness during a disaster event. The real-world challenges of risk bearers (e.g., households, businesses, governments, supranational institutions) to account for such interdependencies are discussed within the context of optimal complexity.

 

Keywords: Individual Risk, Multi-Risk, Compound Risk, Systemic Risk, Dependencies, Optimal Complexity.
Implementation of an upscaled probabilistic fill-and-spill method to simulate wetland-dominated landscapes
Authors: Taheri Mahkameh , Craig James
Published: March 2022

Runoff characteristics of wetland-dominated landscapes are highly influenced by the heterogeneity of wetland properties such as contributing areas, local storage deficits, and degree of connection to the wetland network. Field observations indicate the fill-and-spill process is a common and controlling process in wetland-dominated landscapes in which wetlands receive water until a threshold is satisfied and then release water to the next water bodies in a basin. The upscaled probabilistic fill-and-spill algorithm provided here aims to take the understanding from observation of the fill-and-spill process in individual wetlands at local scales to estimate the response of thousands of wetlands to precipitation or snowmelt events at a larger scale. For this purpose, a novel derived distribution approach is implemented using the probabilistic characteristics of wetlands, i.e., deficit and concentrating factor probability distribution functions. The method proposed here is a generalization of the Probability Distributed Model (PDM) and Xinanjiang probabilistic runoff models with the inclusion of the effects of wetland contributing area and cascading networks. The analytical solution of this upscaled fill-and-spill processes has been compared with a Monte Carlo solution and then implemented in RAVEN, a semi distributed hydrological modelling framework. The accuracy and ability of the model simulation has been tested on ten watersheds in the Qu'Appelle River Basin in Saskatchewan, Canada. The promising simulation results obtained from manual and automated calibration shows strength of the proposed upscaled fill-and-spill algorithm in simulation of low gradient landscapes.
Sensitivity of Heinrich-type ice sheet surges and their implications for the last deglaciation
Authors: Schannwell Clemens , Mikolajewicz Uwe , Ziemen Florian , Kapsch Marie-Luise
Published: March 2022

Transitions from a stable, periodically oscillating ice-sheet system to a perpetual ice stream has potentially far-reaching implications for the timing of the onset of the last deglaciation as well as for climate transitions such as the Younger Dryas. These periodical ice-sheet oscillations known as Heinrich-type ice sheet surges are among the most dominant signals of glacial climate variability. They are quasi-periodic events during which large amounts of ice are discharged from ice sheets into the ocean. The addition of freshwater strongly affects the ocean circulation, resulting in a pronounced cooling in the North Atlantic region. In addition, changes in the ice sheet geometry also have significant effects on the climate. Here, we use a coupled ice sheet-solid earth model that is driven with forcing from a comprehensive Earth System Model that includes interactive ice sheets to identify key drivers controlling the surge cycle length of Heinrich-type ice-sheet surges from two main outlet glaciers of the Laurentide ice sheet. Our simulations show different surge initiation behaviour for the land-terminating Mackenzie ice stream and marine-terminating Hudson ice stream. For both ice streams, the surface mass balance has the largest effect on the surge cycle length. Ice surface temperature and geothermal heat flux also influence the surge cycle length, but to a lesser degree. Ocean forcing and different frequencies of the same forcing have a negligible effect on the surge cycle length. The simulations also highlight that a certain parameter space exists under which stable surge oscillations can be maintained. This parameter range is much narrower for the Mackenzie ice stream than for the Hudson ice stream. Leaving the stable regime results in a dynamical switch that turns the system from periodically oscillating system into a perpetual ice stream system. This transition can lead to a volume loss of up to 36% for the respective ice stream drainage basin under otherwise glacial climate conditions.
On the dynamics of a drift flow under low wind
Authors: Druzhinin Oleg
Published: March 2022

The dynamics of a drift flow in the near-surface water layer driven by a turbulent air wind is investigated by direct numerical simulation (DNS). Comparatively low (up to 2×104) bulk Reynolds numbers of the air-flow are considered when the air boundary layer is turbulent but velocity fluctuations in the water are sufficiently small and the water surface remains aerodynamically smooth. It is shown that a drift flow develops in the near-surface water layer, and its velocity grows monotonically with time. At long times there develops an instability which leads to a saturation of the growth of the drift-velocity. A threshold Reynolds number is defined in DNS under which the drift flow becomes unstable, and a parameterization of the surface drift velocity is formulated in terms of the air-flow friction velocity.
Use of Isotopes in Examining Precipitation Patterns in North-Central Ukraine
Authors: Avery Elizabeth , Samonina Olena , Kryshtop Lidiia , Vyshenska Iryna , Fryar Alan E. , Erhardt Andrea M.
Published: March 2022

North-central Ukraine is vulnerable to temperature increases and precipitation pattern changes associated with climate change. With water management becoming increasingly important, information on current water sources and moisture recycling is critically needed. Isotope ratios of oxygen (δ18O) and hydrogen (δ2H) in precipitation are sensitive to these variables and allow comparisons across the region. For this study, precipitation was collected over a period of one year from Kyiv and Cherkasy and local meteoric water lines were created for both cities. The δ2H and δ18O values from collected precipitation and published 3H data for Kyiv from the year 2000 show an influence of the North Atlantic Oscillation (NAO) and provide information about processes affecting precipitation along the storm trajectory. The δ18O values also show correlation with temperature, indicating that precipitation patterns may be affected by the rising temperatures in the region, as predicted by recent regional studies using Representative Concentration Pathway scenarios and the global climate model GFDL-ESM2M. When compared to backtracked storm trajectory data, clear relationships emerged between water isotope ratios, storm paths, and likely moisture recycling. These results show that when isotopic data are used with backtracked storm trajectories and NAO cycles, a more complete idea of regional processes can be formed, including addition of water vapor from more localized sources. Overall, δ2H, δ18O, 3H, and backtracked storm trajectory data provide more regional and local information on water vapor processes, improving climate-change-driven precipitation forecasts in Ukraine.
The V-FOR-WaTer Virtual Research Environment for Environmental Research
Authors: Strobl Marcus , Azmi Elnaz , Hassler Sibylle K. , Mälicke Mirko , Meyer Jörg , Zehe Erwin
Published: March 2022

The amount and diversity of digitally available environmental data is continuously increasing.  However, they are often hardly accessible or scientifically usable. The virtual research environment V-FOR-WaTer aims at simplifying data access for environmental sciences, fostering data publications and facilitating data analyses.

V-FOR-WaTer already contains many of the necessary functionalities to provide and display data from various sources and disciplines. The detailed metadata scheme is adapted to water and terrestrial environmental data. Present datasets in the web portal originate from university projects and state offices. We are also finalising the connection of V-FOR-WaTer to GFZ Data Services, an established repository for geoscientific data. This will ease publication of data from the portal and in turn give access to datasets stored in this repository. Key to being compatible with GFZ Data Services and other systems is the compliance of the metadata scheme with international standards (INSPIRE, ISO19115).

The web portal is designed to facilitate typical workflows in environmental sciences. Map operations and filter options ensure easy selection of the data, while the workspace area provides tools for data pre-processing, scaling, and common hydrological applications. The toolbox also contains more specific tools, e.g. for geostatistics and for evapotranspiration. It is easily extendable and will ultimately include user-developed tools, reflecting the current research topics and methodologies in the hydrology community. Tools are accessed through Web Processing Services (WPS) and can be joined, saved and shared as workflows, enabling complex analyses and ensuring reproducibility of the results. To build workflows we include an easy-to-use drag and drop user interface.
Understanding Emergent Phenomena in Barchan Swarms Using an Agent-Based Model
Authors: Robson Dominic , Baas Andreas , Annibale Alessia
Published: March 2022

Much of the behaviour of isolated barchans - for instance the existence of a minimal size and the size-dependence of migration rates - is well understood and can be predicted using simplistic models of sand transport.  However, in most instances, barchans do not occur as solitary bedforms but appear in large populations known as swarms.  One can find vast examples of these systems extending for many kilometers and containing tens of thousands of dunes on both Earth and Mars.  Within these swarms, the individual dunes interact through manipulation of the sand flux field which occurs as upwind dunes absorb incoming flux across their entire width and emit flux only through their horns.  Furthermore, the different migration rates of the bedforms lead to collisions which result in the redistribution of mass between the dunes and can also lead to the destruction and creation of barchans. 

  The interactions between barchans in a swarm lead to many emergent phenomena which our knowledge of the isolated bedforms cannot explain.  Several studies have sought to understand, perhaps the most well-documented of these properties, size selection.  However, there has been less attention given to the role played by interactions in governing the spatial structuring of swarms.  It is known, for instance, that barchans tend to align with the horns of their upwind neighbours, this can lead to the formation of striking echelon patterns.  Other reported emergent spatial phenomena include homogeneity of inter-dune spacing and periodicity in spatial correlation functions.  In this presentation we will describe a novel agent-based model we have constructed and discuss the insights it can provide into the nature of the different emergent properties within barchan swarms.  We will compare the results of the model to observations of real-world swarms on Mars and Earth.
Do solid waste landfills really decrease the environmental value? The case of the Valencia Region (Spain)
Authors: Rodrigo-Ilarri Javier , Rodrigo-Clavero María-Elena , Romero Claudia P. , Suárez-Romero Patricio
Published: March 2022

The effect of municipal solid waste landfills over the surrounding environment is often understood to be highly critical, even greatly modifying the existing land use. However, objective evaluations of this environmental impcts are seldom being performed. This work shows results obtained when evaluating the land use change induced by MSW landfills applying the Weighted Environmental index (WEI). WEI is based on the use of GIS techniques accounting for different information sources (digital cartography, aerial photographs and satellite images). WEI assigns environmental values to land use based on the degree of anthropogenic intervention and its occupation surface.

A georeferenced multitemporal statistical analysis is performed considering the values of WEI previously assigned to every land use. The methodology has been applied to analyze the land use change near all the existing MSW landﬁlls in operation of Valencia Region (Spain).  Data have been obtained from the Spanish Land Occupation Information System (SIOSE) public database and integrate the more recent GIS information about land use/land cover. 
Towards structure preserving discretizations of stochastic rotating shallow water equations on the sphere
Authors: Bauer Werner , Brecht Rüdiger , Li Long , Memin Etienne
Published: March 2022

We introduce a stochastic representation of the rotating shallow water equations and a corresponding structure preserving discretization. The stochastic flow model follows from using a stochastic transport principle and a decomposition of the fluid flow into a large-scale component and a noise term that models the unresolved flow components. Similarly to the deterministic case, this stochastic model (denoted as modeling under location uncertainty (LU)) conserves the global energy of any realization. Consequently, it permits us to generate an ensemble of physically relevant random simulations with a good trade-off between the representation of the model error and the ensemble's spread. Applying a structure-preserving discretization of the deterministic part of the equations and standard finite difference/volume approximations of the stochastic terms, the resulting stochastic scheme preserves (spatially) the total energy. To address the enstrophy accumulation at the grid scale, we augment the scheme with a scale selective (energy preserving) dissipation of enstrophy, usually required to stabilize such stochastic numerical models. We compare this setup with one that applies standard biharmonic dissipation for stabilization and we study its performance for test cases of geophysical relevance. 
Uncertainties in multi-model ensemble drought projections and implications on future drought risk
Authors: Pokhrel Yadu , Satoh Yusuke , Elkouk Ahmed
Published: March 2022

Future drought projection studies typically use multi-model ensemble climate and hydrological simulations. In particular, precipitation, soil moisture, and streamflow simulations are used to quantify the changes in meteorological, agricultural, and hydrological droughts under future climate. Many different drought indices have thus been developed and employed in these projections with different indices often leading to varying states of future droughts. Recently, terrestrial water storage (TWS) has also been used to examine future droughts considering integrated climatic and hydrologic impacts on water stores. This presentation will shed light on drought projections using precipitation, soil moisture, runoff, and TWS drought indices and highlight uncertainties in these projections, including those arising from differences in drought definition or the diversity in drought indices. The presentation will then discuss how the consideration of vulnerability alters drought risk projections, specifically by incorporating human development projections as a proxy of broad vulnerability. Results presented will be based on several dozen ensemble hydrological simulations that include multiple climate models, hydrological models, Representation Concentration Pathways (RCPs), and Shared Socioeconomic Pathways (SSPs). Emphasis will be placed on global scale analyses and regional projections over drought hotspots. The results have appeared in three recent publications.
Impact of the Mid-Pleistocene Transition on Meuse River Terraces in the Southern Netherlands
Authors: da Silva Guimarães Ewerton , Kasse Cornelis , Busschers Freek , Bouroullec Renaud , van Balen Ronald
Published: March 2022

River terrace deposits are excellent archives of paleoenvironmental conditions. For this reason, they have been broadly studied, especially the ones dating from the Late Pleistocene and Holocene. On the other hand, little is known about Early Pleistocene terraces due to their state of preservation, which is often not as good as younger terraces, and also due to complications in acquiring good age-dates. The Lower Meuse river, a major tributary of the Rhine river, located in the Southern Netherlands and the adjoining area in northeastern Belgium, exhibits a well preserved terrace staircase which, for decades, has been intensely investigated. The spatial configuration of the terraces is well known, and age constraints, mainly based on correlations made with paleo-climate data from the ODP 677, are also available, which allows for tracing the boundaries of the Early, Middle and Late Pleistocene terraces.

The existing spatial and temporal constraints of these terraces make the Lower Meuse river terrace staircase a suitable object of study for understanding the effects of the Mid-Pleistocene Transition (MPT; 1.2 – 0.8 Ma) in northwest European river systems. In order to achieve that, we aim to compare the different terrace levels according to their ages, and main sedimentary and morphological parameters. More specifically, a comparison will be drawn between pre-, syn and post-MPT terraces. Differences in sedimentary parameters and trends are expected as a result of the climatic deterioration and changes in the duration of climatic events amid the MPT, as well as due to local tectonics (uplift of the Ardennes region). By comparing pre-, syn- and post-MPT terraces, as examples, we expect to find evidences pointing to an acceleration of incision and erosion rates, decrease of terrace width, and increase in grain-size and gravel-accumulation thickness. The comparative assessment will help to clarify how the Meuse river system responded to the MPT, and to what extent these parameters and trends are a product of climate change and/or tectonic forcing.

To achieve the proposed goals, this study updates the Meuse terrace maps for the Netherlands and integrates it with maps of the adjacent regions in Germany and Belgium that also encompass remnants of the Meuse terraces. For that, this study relies on existing maps, a high resolution DEM, and a dense borehole database together with sediment core archives provided by the Geological Survey of the Netherlands (TNO). Concomitantly, we are building a new geochronological framework for the terrace staircase based on cosmogenic nuclides extracted from terraces sediment. We are using both burial isochron (three new age-dates) and simple burial dating methods (twelve new age-dates) in order to trace the MPT boundaries stored in the terraces and infer paleo-erosion and paleo-incision rates.
What is a plate ? Dynamical definition of the transition between lithosphere and asthenosphere
Authors: Garel Fanny , Thoraval Catherine
Published: March 2022

While the lateral limits of tectonic plates are well mapped by seismicity, the bottom boundary of the lithosphere, the uppermost rigid layer of the Earth comprising both crust and shallow mantle, remains elusive. Lithospheric plates are usually viewed as cold, rigid, internally undeformed blocks that translate coherently. The base of the lithosphere, designated as the lithosphere-asthenosphere boundary (LAB), could thus theoretically be characterized from either temperature, viscosity, strain rate and horizontal velocity.

 

 Several LABs as defined from these different fields are investigated here using thermo-mechanical models of plate and upper mantle dynamics, either in a transient subduction or in a steady-state plate-driven set-up. Mantle material is modelled as homogeneous in composition with a viscosity that depends on temperature, pressure and strain rate. In such systems, the thermo-mechanical transition between lithosphere and asthenosphere occurs over a finite depth interval in temperature, strain rate and velocity. We propose that the most useful dynamical LAB is defined as the base of a “constant-velocity” plate (i.e. the material translating at constant horizontal velocity). The bottom part of this plate deforms at strain rates comparable to those in the underlying asthenosphere mantle: the translating block is not fully rigid.

 

Thermal structure exerts a major control on this dynamical LAB, which deepens with increasing plate age. However, the surface plate velocity and more generally the asthenospheric flow geometry and magnitude also impact the depth of the dynamical LAB, as well as the thickness of the deformed region at the base of the constant-velocity plate. Moreover, the mechanical transitions from lithosphere to asthenosphere adjust when mantle dynamics evolves.

 

The dynamical and thermo-mechanical LABs occur within a thermal lithosphere-asthenophere gradual transition, in agreement with the results obtained from geophysical proxies. The concept of a constant-velocity plate can be extended to a constant-velocity subducting slab, which also deforms at its borders and drags the surrounding mantle. This dynamical definition of a lithospheric plate is relevant to interpret mantle seismic anisotropy in terms of (past) flow direction, and to quantify mass transport within the Earth’s mantle.

 
Assessing research gaps in probabilistic tsunami hazard and risk analysis
Authors: Behrens Joern , Løvholt Finn , Jalayer Fatemeh , Lorito Stefano , Salgado-Gálvez Mario A. , Sørensen Mathilde ,   AGITHAR Team
Published: March 2022

Probabilistic tsunami hazard and risk analysis (PTHA/PTRA) is an emerging scientific discipline within the tsuanmi community and allows potentially to incorporate the diverse sources of uncertainty into disaster prevention, preparedness, and mitigation activities. While there are a number of successful applications of this paradigm, it is still an emerging field with a number of unresolved research questions. 

In a collaborative effort members of the COST Action AGITHAR assessed the existing research gaps for PTHA/PTRA and identified almost 50 different topics worth of further research. An ad hoc expert judgement was conducted to weight these open questions with respect to their expected impact on the quality of the PTHA/PTRA results and their difficulty to be answered. The results of this collaborative effort will be reported highlighting the most challenging and most severe research gaps.

The presentation is based on the following publication:
J. Behrens, F. Løvholt, F. Jalayer, et al. (2021): Probabilistic Tsunami Hazard and Risk Analysis – A Review of Research Gaps, Frontiers in Earth Science, 9:114, DOI:10.3389/feart.2021.628772.
Drivers of changes in the permafrost late shoulder season
Authors: Osy Cécile , Massonnet François , Opfergelt Sophie
Published: March 2022

The Arctic has been warming two to four times more rapidly than the global mean in the last decades – a phenomenon known as Arctic Amplification. This warming induces changes for the whole cryosphere, including the permafrost. A first-order marker of permafrost health is the timing of snowfall compared to the timing of the freezing of the upper soil layer, which together determine the length of its late shoulder season. The late shoulder season of permafrost is the period after plant senescence and before the freezing of the active layer of the permafrost. Its length depends on the air temperature, but also on the timing of snowfall. The snow insulates the ground from the atmosphere, and snow cover will delay the freezing of the ground if it falls before the air temperature drops below freezing point. On the other hand, if the snowfall occurs after the ground freezing, it is expected that the freezing will be more persistent and will reach deeper soil layers more rapidly.

There is to date no large-scale view of the late shoulder season characteristics in the Arctic permafrost regions and how this shoulder season is evolving in a warming Arctic. Here, a study of the temporal variability of the late shoulder season of the permafrost is proposed. To that end, the temporality of the first relevant snowfall and freeze of the top layer of the ground is studied from 1950 to 2020 in the ERA5-Land reanalysis. The temporal trends will be spatialized to account for the spatial heterogeneity of the study area, and to study which variables other than the snow (vegetation, topography, …) influence the length of the shoulder season. The surface pressure and atmospheric circulation in the ERA5 reanalysis is also looked at to explain punctual extreme events and interannual trends..
The potential of geothermal district heating in the city of Banja Luka, Bosnia and Herzegovina
Authors: Gvero Petar , Jón Ásbjörnsson Einar , Finger David , Kotur Milovan , Musonye Xavier , Kardas Danijela , Pupcevic Milan
Published: March 2022

The geothermal energy potential in the Balkan area includes locations in Slovenia, Hungary, Romania, Bulgaria, Serbia and Bosnia and Herzegovina. Although the potential for clean, cost-efficient, and renewable geothermal heating energy is well known, exploitation of geothermal sources is still hampering. According to the existing surveys, mappings, and calculations, Banja Luka area is built on a geothermal underground reservoir, which is currently only used for balneology purposes. Due to the specific geographic position and the emissions from the existing district heating system based on biomass and heavy petrol, the air quality in Banja Luka is severely mitigated during the winter season. In order to assess the potential and the challenges of geothermal district heating for Banja Luka numerical energy modeling, life cycle analysis of the energy systems, and stakeholder assessment are currently being performed. These activities are currently carried out in the frame of international cooperation between the University of Banja Luka, Reykjavik University in Iceland, and the Energy Institute at the Johannes Kepler University in Linz, Austria. Our preliminary results indicate that geothermal district heating in Banja Luka can provide a reliable, cost-efficient, clean, renewable, and domestic heat supply to the residents of Banja Luka. Furthermore, our initial findings indicate that that the main challenges in developing geothermal district heating in Banja Luka are complex bureaucratic processes, high skepticism among the decision-makers, and a high degree of conflicting interests among relevant stakeholders. This presentation will conclude by highlighting how geothermal district heating in Banja Luka falls in line with the concepts of the new EU Green Deal and the obligations of Bosnia and Herzegovina according to Energy Community Treaty.