bluuebunny/crossref_metadata_2025 huggingface dataset:
When it rains it pours: Mapping and characterization of compound events in Sweden
Authors: Mård Johanna , Bodin Örjan , Nohrstedt Daniel
Published: March 2021

Economic losses caused by natural hazards are increasing in many areas across the world. Sweden is not an exception to these trends. For example, in 2018 Sweden experienced the warmest summer ever on record. Wildfires were frequently reported, together with reports on thunder storms, extreme precipitation events, floods and prolonged drought conditions. These events resulted in considerable economic losses and required coordination on an unprecedented scale, including international assistance. Considerable knowledge gaps remain on how to effectively mitigate societal effects of compound events. Current risk assessments often focus on single hazards within distinct administrative boundaries whereas compound events, which often transcend these boundaries, are rarely accounted for. This poses a problem – particularly in vulnerable geographical areas where the risk for compound events with significant societal impacts is high. Here we present a new project that will address this knowledge gap, with the aims to identify underlying factors and causal chains of compound events in Sweden, and to investigate capacities among public and private actors to mitigate these impacts via effective collaboration. The first outcome is an integrated natural hazards map that reveals how climate-related natural hazard events have evolved over time and space in Sweden since the 1970s, and what areas are most exposed and vulnerable to compound events. These results provide knowledge on the spatiotemporal distribution of natural hazard events, including compound events, which is critical when analyzing their underlying drivers.
Effects of snowmelt on the runoff dynamics in two catchments with different forest stands
Authors: Juras Roman , Vystavna Yuliya , Paule-Mercado Ma Cristina , Schmidt Susanne I. , Kopacek Jiri , Hejzlar Josef , Huneau Frederic
Published: March 2021

The forest stand can significantly affect the snow deposition and consequently the runoff during the melt period. This study focuses on water and element fluxes from snowpack in two Czech boreal headwater lake catchments with different forest stands (mature vs. regenerating after bark beetle tree dieback) using isotopic and hydrochemical tools. Sampling and analysis of the surface water, precipitation and snowpack throughout one  hydrological year enabled us to estimate the isotopic balance and chemical snowpack evolution, but also the snowmelt contribution in lakes inlets and outlets.

Isotopic signatures of the snowpack were seasonal, with δ2H amplitudes of -25‰ in the mature and -17‰ in the regenerating forest catchments. The mature forest had a ~1 month longer duration of snow cover and higher concentration of solutes in the precipitation and snowpack. In both catchments, heavier isotopes (18O and 2H) preferentially left the snowpack, which was saturated with rainwater. This resulted in the final spring snowmelt being enriched with lighter isotopes (16O and 1H). Ions were also eluted from the snowpack during rain-on-snow events and partial snow melting throughout the winter, causing fluxes of diluted water at the end of the snowmelt. Our results demonstrate the hydrological and hydrochemical variability of the snowpack, which in the future may even increase with rising temperatures and changes of precipitation patterns.
Subpolar Southern Ocean response to changes in the surface momentum, heat and freshwater fluxes under 2xCO2
Authors: Boeira Dias Fabio , Domingues Catia , Marsland Simon , Rintoul Stephen , Uotila Petteri , Fiedler Russ , Mata Mauricio , Savita Abhishek
Published: March 2021

The subpolar Southern Ocean (sSO) around Antarctica has fundamental climate importance. The densest water mass in the global ocean, Antarctica Bottom Water (AABW), originates in the sSO and supplies the lower limb of the Meridional Overturning Circulation (MOC), occupying about 36% of the ocean’s volume. However, climate models struggle to represent the processes involved in formation of AABW on the continental shelf, resulting in large differences between models and observations and a wide spread in projections of sea level and other properties. We explore the source of these persistent model biases by examining the response of the sSO to perturbations in surface forcing. Using an ocean-sea ice model (ACCESS-OM2) that forms AABW both on the shelf and in open-ocean (similar to other coarse resolution models), we investigate the sSO response to individual and combined perturbations of surface heat, freshwater and momentum fluxes following the  FAFMIP-protocol. The wind perturbation (i.e. a poleward shift and intensification of the Southern Ocean Westerlies) has the dominant effect, enhancing AABW formation and accelerating the MOC. This occurs through upwelling of warm waters and inhibition of sea-ice growth during winter, which triggers large open-ocean polynya events with associated deep convection. These events occur in the Weddell and Ross Seas and their variability is associated with the heat available at mid-depth; open-ocean polynyas cease when the heat reservoir is depleted. The effects of surface warming and freshening only partially compensate the changes due to wind by increasing the ocean stratification and reducing AABW formation. These results are relevant for the interpretation of climate change projections, suggesting that other coarse  models might respond in similar way and present an opposite trend than those seen from observations.
The impact of hedges maturation on soil organic carbon stocks in agricultural landscapes
Authors: Biffi Sofia , Chapman Pippa j , Grayson Richard P , Ziv Guy
Published: March 2021

Hedgerows can provide a wide range of regulatory ecosystem services within improved grassland landscapes, such as soil function improvement, soil erosion reduction, biodiversity, water quality, and flood prevention and mitigation. Because of their beneficial effects, farmers are incentivised to retain their hedgerows and the planting of hedges has been encouraged in agri-environment schemes in Europe. Today, hedgerow planting it is one of the most popular practices adopted in the Countryside and Environmental Stewardships in England. The role of hedgerows in climate change mitigation has been increasingly recognized over the past decade, however, while other services have been more widely studies, less is known about hedges soil organic carbon (SOC) storage capacity. The Resilient Dairy Landscapes project aims at identifying strategies to reconcile dairy systems productivity and environment in the face of climate change, and with the Committee on Climate Change calling for a 30% - 40% increase in hedgerow length by 2050 in the UK, it is important to determine the role of hedgerows in meeting Net Zero targets. In this study, we estimate the extent of SOC stock beneath hedges and how it may vary with depth, hedge management and age, as well as how it may compare to SOC stock in adjacent agricultural fields. Thus, we measured SOC under 2-4 years old, 10 years old, 37 years old, and 40+ years old hedgerows at 10 cm intervals up to 50 cm of depth under 32 hedges located on dairy farms in Cumbria, UK. We found that the time since planting and the depth of samples play a crucial role in the amount of SOC stock stored underneath hedgerows when accounting for differences in soil type. Our results contribute measurable outcomes towards the estimate of targets for Net Zero 2050 and the extent of ecosystem services provision by hedgerow planting in agricultural landscapes.  
Mercury concentrations in thermal waters of the Bolshoi Semyachik hydrothermal system, Russia, Kamchatka.
Authors: Nuzhdaev Anton
Published: March 2021

The study of mercury receipt within volcanic activity zones and large hydrothermal systems recently causes the big interest connected with attempts of an estimation of volumes of natural mercury receipt on a daily surface.

The hydrothermal system connected with volcanic massif Big Semyachik is one of the largest on the territory of Kamchatka peninsula. On the surface, the hydrothermal system is manifested by three large hydrothermal fields - the Verhnee Field, the parychay Dolina, and the Northern Crater of the Central Semyachik, the heat export from which is estimated at 300 MW (Vakin, 1976). On the surface of the thermal fields hot thermal waters and powerful steam-gas jets are unloaded.  At the same time, due to the inaccessibility of thermal fields remain poorly studied, and in particular, there is no information on the concentrations of mercury in hydrothermal solutions.

During fieldwork in 2020 all types of thermal waters were sampled, chemical types of waters were established, concentrations of mercury in hydrothermal solutions: for hot thermal waters the average value of mercury was - 0.44 mcg / L, and in steam-gas jets - the average value of mercury was - 4.60 mcg / L.

Thus, in the course of the work the data on concentrations of mercury in hydrothermal solutions of one of the largest hydrothermal systems of Kamchatka were received for the first time.

 
Interpretation of Atmospheric CO2 Measurements in Mexico City
Authors: Xu Yang , Ramonet Michel , Lauvaux Thomas , Lian Jinghui , Bréon Francois-Marie , Ciais Philippe , Grutter Michel , Garcia Agustin
Published: March 2021

The French-Mexican project Mexico City’s Regional Carbon Impacts (MERCI-CO2) is building a CO2 observation network in the Metropolitan Zone of the Valley of Mexico (ZMVM). The project investigates the atmospheric signals generated by the city's emissions on total column and surface measurements, aiming at reducing the uncertainties of CO2 emissions in ZMVM and evaluating the effects of policies that had been implemented by the city authorities. 

A nested high-resolution atmospheric transport simulation based on the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) is performed to analyze the observed CO2 mixing ratios during dry and wet seasons over Mexico City and its vicinity. Both anthropogenic emissions (UNAM 1-km fossil fuel emissions) and biogenic fluxes (CASA 5-km simulations) are taken into account. The model configuration, with a horizontal resolution of 1km and using the Single-Layer urban canopy Model (SLUCM), has been evaluated over two weeks in January 2018 using meteorological measurements from 26 stations set by the Air Quality Agency of Mexico City (Secretary of the Environment of Mexico City - SEDEMA). The reconstruction of meteorological conditions in the urban area shows better performances than suburban and mountainous areas. Due to the complex topography, wind speeds in mountain areas are 2-3 m/s over estimated and wind direction simulations in some stations are 90° deflected, especially in southern mountains. 

Two high-precision CO2 analyzers deployed in urban and rural areas of Mexico City are used to evaluate the WRF CO2 1-km simulations. The model reproduced the diurnal cycle of CO2 mixing ratios at the background station but under-estimates the nighttime accumulation at the urban station. Mean absolute errors of CO2 concentrations range from 6.5 ppm (background station) to 27.1 ppm (urban station), mostly driven by the elevated nocturnal enhancements (up to 500 ppm at UNAM station). Based on this analysis, we demonstrate the challenges and potential of mesoscale modeling over complex topography, and the potential use of mid-cost sensors to constrain the urban GHG emissions of Mexico City.
Roles of photosynthetic, respiratory, stomatal and phenological acclimation in controlling carbon and water fluxes of mature Norway spruce in a changing climate  
Authors: Lamba Shubhangi , Duursma Remko A. , Hasper Thomas B. , Sigurdsson Bjarni D. , Medlyn Belinda E. , Tarvainen Lasse , Hall Marianne , Linder Sune , Wallin Göran , Uddling Johan
Published: March 2021

Boreal regions are undergoing rapid climate change but our understanding of the long-term consequences for forest processes is hampered by limited knowledge of how trees acclimate to rising atmospheric CO2 concentrations and temperature. This study used the detailed canopy flux model MAESTRA to simulate the effects of elevated CO2 (eCO2) and warming on net photosynthesis (An) and transpiration (E) of mature boreal Norway spruce, investigating how these effects are influenced by the observed acclimation of photosynthetic capacity, respiration, stomatal behavior, and phenology. Without any type of acclimation, eCO2 increased shoot and crown An during the non-frost growing season by 23-44%, while warming only had a minor effect (±2%). Photosynthetic downregulation greatly decreased the positive effect under eCO2. Under warming, both stomatal and phenological acclimation had substantial effects on An but in opposite directions. Transpiration at shoot and crown level was greatly decreased (23-50%) by eCO2 and increased by warming (27-42%) in the absence of acclimation. However, both these effects were largely cancelled by stomatal acclimation. Effects of eCO2 on An were generally smaller at entire crown compared to shoot level, as a result of photosynthetic stimulation being smaller in shaded canopy positions. In addition, upregulation of respiration in eCO2 had a considerably larger negative effect on An at crown compared to shoot level. Overall, tree physiological acclimation generally acted to dampen non-acclimated responses. We conclude that photosynthetic and respiratory acclimation greatly reduce the positive effect of eCO2 on tree CO2 assimilation, while stomatal and phenological acclimation are crucial for annual water consumption under warming. These results highlight the critical need to account for acclimation in models.

 
On the origin of Ultra-Low Frequency (ULF) waves in sudden and quasiperiodic solar wind dynamic pressure variations penetrating into Earth’s magnetosphere
Authors: Georgiou Marina , Katsavrias Christos , Daglis Ioannis , Balasis Georgios , Hillaris Alexander
Published: March 2021

Several observational studies have shown that external (i.e. solar wind and magnetosheath) dynamic pressure variations can drive quasi-periodic perturbations of the geomagnetic field. In this study, we utilise multi-spacecraft (ARTEMIS, Cluster, GOES, and THEMIS) mission measurements and investigate step-like increases and quasi-periodic variations of solar wind dynamic pressure as the source mechanism of geomagnetic pulsations with frequencies between ~0.5 to 15 mHz. During intervals of slow solar wind and low geomagnetic activity — to exclude waves generated by velocity shear at the magnetopause and substorm contributions — common periodicities in electromagnetic field oscillations inside the magnetosphere and the solar wind driver are detected in Lomb-Scargle periodograms. The causal relationship is examined in frequency and polarisation signatures of waves detected at the various probes using continuous wavelet transform, cross-wavelet spectra and wavelet transform coherence. The observed dependence of wave properties on their localisation offers excellent source verification for ULF Pc4-5  waves originating in dynamic pressure variations in the upstream solar wind and propagating in the dayside magnetosphere through the field line resonance process.

This research is co-financed by Greece and the European Union (European Social Fund - ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning 2014-2020” in the context of the project ULFpulse (MIS: 5048130).
Data-streaming workflow for seismic source location with PyCOMPSs parallel computational framework
Authors: Poiata Natalia , Conejero Javier , Badia Rosa M. , Vilotte Jean-Pierre
Published: March 2021

Modern digital seismic networks record a wealth of high-quality continuous waveforms that contain a variety of signals associated to a wide range of seismic sources (e.g., earthquakes, volcanic, tectonic tremors, environmental sources) that probe transient energy release processes. Efficient and automatic detection, location and characterization of these different seismic sources is critical to understand slowly-driven evolution of active tectonic and volcanic systems toward catastrophic events. Developing a common analysis framework for systematic exploration of the increasing wealth of seismic observation streams is important for improving seismic monitoring systems and extracting large and accurately resolved seismic source catalogues.

To this end, we present a scalable parallelization with PyCOMPSs (Tejedor et al., 2017) of the python-based BackTrackBB data-streaming workflow (Poiata et al., 2016; 2018) for automatic detection and location of seismic sources from continuous waveform streams recorded by large seismic networks. This allows achieving an efficient distribution and orchestration of BackTrackBB code on different architectures. PyCOMPSs is a task-based programming model for python applications that relies in a powerful runtime able to extract dynamically the parallelism among tasks and executing them in distributed environments (e.g. HPC Clusters, Cloud infrastructures, etc.) transparently to the users.

We will provide details of the PyCOMPSs-based BackTrackBB workflow implementation. Results of scalability tests and memory usage analysis will be also discussed. Tests have been performed, in the context of the European Centre Of Excellence (CoE) ChEESE for Exascale computing in solid earth sciences, on the MareNostrum4 High-Performance computer of the Barcelona Supercomputing Centre, using large-scale datasets of synthetic and real-case seismological continuous waveform data sets.
Modelling the occurrence of convective hazards using ERA5 reanalysis data
Authors: Battaglioli Francesco , Groenemeijer Pieter , Pucik Tomas , Ulbrich Uwe , Rust Henning , Kühne Thilo , Taszarek Mateusz
Published: March 2021

Convective hazards such as large hail, severe wind gusts, tornadoes, and heavy rainfall cause high economic damages, fatalities, and injuries across Europe. There are insufficient observations to determine whether trends in such local phenomena exist, however recent studies suggest that the conditions supporting such hazards have become more frequent across large parts of Europe in recent decades.

We model the occurrence of these hazards using Generalized Additive Models (GAM) to investigate the existence of such long-term trends, and to enable objective probabilistic forecasts of these hazards. The models are trained with storm reports from the European Severe Weather Database (ESWD), lightning observations from the EUCLID network, and predictor parameters derived from the ERA5 reanalysis. Our work is based on the framework AR-CHaMo (Additive Regression Convective Hazard Models), previously developed at ESSL.

Preliminary results include a spatial depiction of the environmental conditions giving rise to convective hazards at a higher resolution than was possible before. The skill of hail models developed using AR-CHaMo has been shown to be superior to composite parameters used by weather forecasters for the occurrence of large hail, such as the Supercell Composite Parameter (SCP) and the Significant Hail Parameter (SHP). Likewise, for tornadoes, more skillful models can be constructed using the AR-CHaMo framework than predictors such as the Significant Tornado Parameter (STP).

The developed models have use both in climate studies and in medium-range severe weather forecasting. We will report on initial efforts to detect long term (1979-2019) trends of convective hazards and present how these models can be used to support severe weather forecasting using medium-range ensemble forecasts.
Exploring the effects of adaptation policies on sea-level rise-induced migration at continental scale
Authors: Reimann Lena , Jones Bryan , Wolff Claudia , Vafeidis Athanasios
Published: March 2021

Accelerating sea-level rise (SLR) in the course of the 21st century will lead to population displacement and migration, the intensity and patterns of which will largely depend on the type and efficiency of adaptation strategies pursued. Thus far, the potential feedbacks between adaptation and SLR-induced migration have not been considered in continental-scale assessments. This study explores the effect of three coastal adaptation policy scenarios – 1) ‘build with nature’, 2) ‘hold the line’, 3) ‘save yourself’ – on migration due to SLR, using a gravity-based population downscaling model calibrated to the Mediterranean region. The policy scenarios are consistent with the socioeconomic developments described under the Shared Socioeconomic Pathways (SSPs). Combining these with a range of SLR scenarios, we produce spatial population projections from 2020 to 2100 that allow for estimating SLR-induced migration with and without adaptation. Preliminary results show that, without adaptation, SLR may lead to migration of 10 million (SSP1-RCP2.6) to 16 million (SSP3-RCP4.5) people currently living in low-lying coastal areas of the Mediterranean until 2100. With adaptation, the number of migrants until 2100 could be reduced by 2.1 million under the ‘build with nature’ scenario (SSP1-RCP2.6) and by up to 6 million under the ‘hold the line’ scenario (SSP5-RCP8.5). These results suggest that adaptation can be effective in reducing the number of migrants due to SLR, in particular when engineered solutions such as dikes are pursued. However, while the number of SLR-related migrants can be reduced by 50% under the ‘hold the line’ scenario, impacts would be high in case of protection failure during extreme sea level conditions. Allowing for exploring the effects of different adaptation policies on SLR-induced migration, we anticipate that our findings can provide a suitable basis for decision-making, for example in adaptation planning or regional development planning.
Chasing the Magma Chamber: MT meets Geodynamics and Seismology – A numerical case study of magmatic plumbing at Oldoinyo Lengai Volcano
Authors: Castro César Daniel , Reiss Miriam Christina , Spang Arne , Hering Philip , de Siena Luca , Komeazi Abo , Zhang Yi , Rümpker Georg , Kaus Boris , Junge Andreas
Published: March 2021

How well can geophysical methods image magmatic systems? Geophysical methods are commonly used to image magmatic systems; however, synthetic studies which give insights into the resolution of such methods and their interpretational scope are rare. Gravity anomalies, magnetotelluric, seismological and geodynamical modelling all have a different sensitivity to the rock parameters and are thus likely complementary methods. Our study aims to better understand their interplay by performing joint modelling of a synthetic magmatic system.  Our model setup of a magma chamber is inspired by seismological observations at the Natron plumbing system including active volcano Oldoinyo Lengai within the East African Rift system. The geodynamic modelling is guided by shear-wave velocity anomalies and it is constrained by a large Bouguer gravity anomaly which is modelled by a voxel-based gravity code. It yields the 3D distribution of several geological parameters (pressure, temperature, stress, density, rock type). The parameters are converted into a 3D resistivity distribution. By 3D forward modelling including the topography, synthetic MT transfer functions (phase tensor, induction vectors) are calculated for a rectangular grid of 441 sites covering the area. The variation of geodynamic parameters and/or petrological relations alters the related resistivity distribution and thus yields the sensitivity of MT responses to geodynamic parameters. In turn, MT observations may constrain geodynamic modelling by inverting MT transfer functions. The inversion is performed allowing for the recent seismicity distribution beneath the Natron plumbing system, assuming that active seismic areas are related to enhanced resistivity. The inversion is performed for a realistic distribution (in view of logistic accessibility) of about 40 MT sites.

By combining multiple forward models, this study yields insights into the sensitivity of different observables and thus provides a valuable base on how MT, gravity and seismological observations can help imaging a complex geological setting.
Disentangeling the shortwave surface energy balance in earth system models
Authors: Moseid Kine Onsum
Published: March 2021

The Earth’s surface energy balance is heavily affected by incoming solar radiation and how it propagates through our atmosphere. How the sunlight propagates towards the surface depends on the atmospheric presence of aerosols, gases, and clouds. 

Surface temperature evolution according to earth system models (ESMs) in the historical experiment from the coupled model intercomparison project phase 6 (CMIP6) suggests that models may be overly sensitive to aerosol forcing. Other studies have found that ESMs do not recreate observed decadal patterns in surface shortwave radiation - suggesting the models inaccurately underestimate the shortwave impact of atmospheric aerosols. These contradictory results act as a basis for our study.
Our study decomposes what determines both all sky and clear sky downwelling shortwave radiation at the surface in ESMs, using different experiments of CMIP6. We try to determine the respective role of aerosols, clouds and gases in the shortwave energy balance at the surface, and assess the effect of seasonality and regional differences.
Vessel-based optical data and artificial intelligence for sampling mega-plastic concentrations on the high seas
Authors: de Vries Robin , Egger Matthias , Mani Thomas , Lebreton Laurent
Published: March 2021

Remote sensing of marine debris has seen recent successes in coastal regions. However, these approaches focus on the detection of large accumulations of marine debris, often mixed with organic waste and related to events. Individual large plastic items (macroplastics, > 50cm) in remote marine environments are a substantial part of the marine debris surface mass budget, yet  remain poorly quantified.

Current knowledge on the accumulation of macroplastic debris at the ocean surface is mostly limited due to methodological constraints. Macroplastics are typically too large for collection by neuston trawls. Furthermore, the relatively small sea surface area typically investigated during offshore research expeditions often is too small to account for the low areal concentrations of macroplastics. Given the importance of macroplastic in the global ocean plastic mass balance, quantitative information on the spatiotemporal distribution of macroplastics afloat in the surface ocean are urgently needed.

By now, our location-enabled action camera's on-board vessels of opportunity have recorded a vast amount of optical data from the North Pacific and North Atlantic Ocean (approximately 1 million images). By selection and labelling of occurrences of debris in images, we have trained an object detection and localization algorithm. We use the camera’s intrinsic parameters to estimate relevant sampling parameters, such as size and distance of each object detected. An overview of numerical concentrations is generated by combining the object detection solution with bulk processing of the optical data. The first results are promising and well-comparable to sampling methods applicable to smaller debris size classes, such as surface neuston nets.
Volcanic impact on the tropical hydrological cycle 
Authors: D'Agostino Roberta , Timmreck Claudia
Published: March 2021

The impact of volcanic forcing on tropical precipitation is investigated in a new set of sensitivity experiments within Max Planck Institute Grand Ensemble framework. Five ensembles are created, each containing 100 realizations for an idealized tropical volcanic eruption located at the equator, analogous the Mt. Pinatubo eruption, with emissions covering a range of 2.5 - 40 Tg S. The ensembles provide an excellent database to disentangle the influence of volcanic forcing on regional monsoons and tropical hydroclimate over the wide spectrum of the climate internal variability. Monsoons are generally weaker during the two years after volcanic eruptions and their weakening is a function of emissions: the strongest the volcanic eruption, the weakest are the land monsoons. The extent of rain belt is also affected: the monsoon area is overall narrower than the unperturbed control simulation. While the position of main ascents does not change, the idealised tropical volcanic eruption supports the shrinking of Hadley Cell's ascent and the narrowing of the ITCZ. We investigate this behavior by analysing the changes in Hadley/Walker circulation, net energy input and energy budget to find analogies/differences with global warming.
Defining potential multi-hazard and multi-risk combinations for infrastructure and other economic sectors using empirical pan-European examples
Authors: Daniell James , Schaefer Andreas , Skapski Jens , Romero Roberth , Ward Philip , de Ruiter Marleen , Couasnon Anais , de Bruijn Jens , Brand Johannes , Khazai Bijan , Wenzel Friedemann , Girard Trevor
Published: March 2021

A new complex world is emerging where a natural hazards event in a certain location, can have significant impacts on a different location either interlinked via economic sectors, infrastructure systems or other social relationships. In the past this was often not able to be quantified, but with increased reporting we are able to define these interactions better than previously.

For a single location, multiple hazards can also occur in tandem, or one after another causing impacts or as a standalone. However, standalone events currently take on a whole new complexity with coronavirus protocols.

Within the course of the EU project NARSIS (New Approach to Reactor Safety ImprovementS), sites of decommissioned nuclear power plants (NPPs) were investigated for external hazards combinations using a multi-hazard approach which took into account the joint probabilities including operational times and the effects of subsequent events. Here, different external hazards were applied such as tornadoes, lightning, earthquakes, floods and volcanic eruptions in tandem calibrated on historical events.

In this work, we build a pan-European database using the backbone of CATDAT to define multi-hazard events of relevance with overlapping hazard and loss effects including events in 2020 and 2021 with significant effects due to coronavirus in combination with another hazard. We focus on the 1980-2021 time period within this database, although many older events have also been collected.

In the year 2020, numerous events including the Croatian and Greece/Turkey earthquakes, medicanes, bushfires and many flood and storm events showed the complexity of combining multi-hazard protocols concurrently.

The database will be extended within the MYRIAD-EU project in order to inform a multi-risk, multi-sector, systemic approach to risk management. Using empirical examples of socio-economic effects is one key step to understand the overlaps, and important within the calibration process of any multi-risk model.
Eigenvalue decomposition polarization analysis: A regularized sparsity-based approach
Authors: Almeida Eduardo , Mohammadigheymasi Hamzeh , Fathi Maryam , Crocker Paul , Silveira Graça
Published: March 2021

Polarization analysis is a signal processing tool for decomposing multi-component seismic signals to a set of rectilinearly or elliptically polarized elements. Theoretically, time-frequency polarization methods are the most compatible tool to analyze the intrinsically non-stationary seismic signals. They decompose the signal to a superposition of well-defined polarized elements, localized in the time and frequency domains. However, in practice, they suffer from instability and limited resolution for discriminating between interfering seismic phases in time and frequency, as the time-frequency decomposition methods are generally an underdetermined mapping from the time to the time-frequency domain. Our contribution is threefold: Firstly we obtain the frequency-dependent polarization properties in terms of the eigenvalue decomposition of the Fourier spectra of three-components of the signal. Secondly, by extending from the frequency to the time-frequency domain and using the regularized sparsity-based time-frequency decomposition (Portniaguine and Castagna, 2004) we are able to increase resolution and reduce instability in the presence of noise. Finally, by combining directivity, rectilineary, and amplitude attributes in the time-frequency domain, we extend the time-frequency polarization analysis to extract and filter different seismic phases. By applying this method on synthetic and real seismograms we demonstrate the efficacy of the method in discriminating between the interfering seismic phases in time and frequency, including the body, Rayleigh, Love, and coda waves. This research contributes to the FCT-funded SHAZAM (Ref. PTDC/CTA-GEO/31475/2017) project.

REFERENCES
Portniaguine, O., and J. Castagna, 2004, Inverse spectral decomposition, in SEG Technical Program Expanded Abstracts 2004: Society of Exploration Geophysicists, 1786–1789.
Assessing the stability of the AMOC during past warm climates
Authors: Murphy O' Connor Megan , Colin Christophe , Morley Audrey
Published: March 2021

There is emergent evidence that abrupt shifts of the Atlantic Meridional Overturning Circulation (AMOC) have occurred during interglacial periods, with recent observations and model simulations showing that we may have over-estimated its stability during warm climates. In this study, we present a multi-proxy reconstruction of deep-water characteristics from the Rockall Trough in the Eastern North Atlantic to assess the variability of Nordic seas and Labrador Sea deep-water formation during past interglacial periods MIS 1, 5, 11, and 19. To test the warm climate stability hypothesis and to constrain the variability of deep-water formation for past warm climates, we performed geochemical analysis on planktic (Nd isotopes) and benthic foraminifera (δ18O and δ13C) along with sedimentological analysis. This approach allows us to reconstruct paleocurrent flow strength, as well as the origin and contribution of different water masses to one of the deep-water components of the AMOC in the Rockall Trough. We found that deep-water properties varied considerably during each of our chosen periods. For example during the Holocene εNd variability is smaller (1.8 per mil) when compared to variability during MIS 19 (3.3 per mil), an interglacial that experienced very similar orbital boundary conditions. Our results confirm that deep-water variability in the eastern North Atlantic basin was more variable in previous interglacial periods when compared to our current Holocene and provide new insight into the relative contribution of Nordic Seas Deep Water and Labrador Sea Water in the Rockall trough.
Laboratory and numerical investigation of the factors controlling the residence time of microplastics in the water column of thermally stratified lakes
Authors: Elagami Hassan , Ahmadi Pouyan , Frei Sven , Obst Martin , Gilfedder Benjamin
Published: March 2021

Plastics are among the most widespread contaminants on Earth. They build up in fresh water bodies with high concentrations and migrate between different environmental compartments. In thermally stratified lakes, in summer, MPs pollutants can migrate between epilimnion, metalimnion and hypolimnion. This increases the probability of that microplastic will be filtered by filter feeders allowing MPs to migrate through different trophic levels. In this study, the transport of MPs in lake systems is presented through laboratory experiments as well as numerical modelling. The settling velocities of various biodegradable and non-biodegradable particles with various shapes and sizes were measured in the settling column under laminar conditions using particle image velocimetry (PIV). The particles used ranged between 150 to 2400 µm in diameter. The experimental results presented that shape, size and density of a particle are the key parameters controlling the sedimentation behavior of the particles. The measured settling velocities ranged between 0.4 to 50 mms-1. In parallel, the transport of the particles used in the laboratory experiments was simulated using CFD. The laboratory experiments and CFD have shown consistent results. Subsequently, the same MPs used in the first lab experiments were incubated in a pond at the University of Bayreuth for 6, 8 and 10 weeks. The formation of biofilm on the incubated particles was investigated using confocal laser scanning microscopy. Also, the effect of biofouling of microplastics on the physical properties and thus settling velocity was investigated experimentally. It was observed that biofilm-building organisms has only colonized few regions on the surface of MPs and the whole surface was not coated with biofilm as it was anticipated. In addition, no changes in shape, size and density of the incubated were detected. After 6, 8 and 10 weeks of incubation, no significant change in the settling velocity of the incubated particles was observed. The detected changes in the settling velocity ranged between ± 5 % which was considered as a measurement error. Finally, the residence time in suspension and the distribution of MPs throughout a virtual lake water column was simulated using a simplified model. The effect of turbulences and the temperature gradient on the settling velocity were considered during the simulations. The model presented that turbulences, water temperature and layer depth control the settling velocity and thus the residence time of the MPs.
A state-based and optimal path dependant short-term flood planning 
Authors: Ni Mengke , Erfani Tohid
Published: March 2021

Temporary flood protective defences (TFPD) are supplementary to permanent engineering solutions. In a flood event, asset managers are faced with a challenging task of deploying large-scale temporary defences at multiple locations. As the performance of temporary defences is sensitive to various uncertain weather condition factors, it is difficult to fix a single specific deployment plan as the optimal solution. This, moreover, leads to insufficient and/or underused defences on flood-affected locations. This paper describes a state-based (SB) mathematical modelling approach to deal with above challenge by adapting TFPD strategies consistently to short-term future as they unfold. We employ multistage stochastic and scenario tree to identify a set of alternative SB optimal paths for deployment planning. The proposed model is applied to nine flood-affected locations in Carlisle, northwest England. The results indicate that the inclusion of SB path-dependant solution strategy are beneficial for the flood asset manager faced with making short-term deployment planning decisions.
Geometric morphometric analysis of different species of Cyprideis deriving from the Early Pleistocene record of Greece.
Authors: Dimitriou Ypermachia , Papadopoulou Penelope , Kolendrianou Maria , Tsoni Maria , Iliopoulos George
Published: March 2021

The genus Cyprideis is one of the most widespread ostracod representative of the Pleistocene brackish palaeoenvironments. Especially Cyprideis torosa is often found in great numbers and even in monospecific taphocoenoses and for this reason its study is very useful for palaeoenvironmental reconstructions.  The identification of different species of Cyprideis is often complicated and needs careful morphology inspection. This becomes even more difficult in the case of endemic species which present significant similarities with each other.  In this work, we have studied and analyzed several  Cyprideis species (C.torosa, C. frydaci, C.dictyoti, C. pannonica, C. elisabeta, C. seminulum, C. heterostigma) deriving from brackish palaeoenvironments of a Lower Pleistocene marl sequence in Sousaki Basin (Northeastern Corinth Graben, Greece). More specifically size measurements and geometric morphometrics (lateral valve outline of both right and left valves as well as females and males) were used in order to attest the similarities and dissimilarities between the different species and draw conclusions about their origin.  According to the valve outline and the multivariate analysis a close relationship between the valve shape of all Cyprideis species can be noticed. C. torosa is commonly grouped with C. pannonica except in the male right valve where the two species show some differences.  The endemic species C. frydaci and C. dictyoti can be identified by the differences in the right valve of the male and female respectively.  The other species could not be substantially differentiated using just the outline analysis which possibly denotes their common genetic origin.  The valve outline has proved to be a very useful character for recognizing the different species especially when the two valves of both females and males are considered. More analyses of representative species of Miocene and Pliocene Cyprideis are needed in order to establish their phylogenetic relationships and draw conclusions about their common ancestor.
Earth system resilience through planetary active inference.
Authors: Rubin Sergio , Da Costa Lancelot , Friston Karl
Published: March 2021

We formalize the resilience of the Earth system under the free energy principle (Friston 2013; Parr et al, 2019; Rubin et al, 2020). This allows us to understand resilience as the self-maintenance of a non-equilibrium steady-state. This autopoietic steady-state depends on gradient flows that counter entropic dissipation by random fluctuations. These flows can also be interpreted in a statistical sense, which amounts to the claim that resilience depends upon the Earth system possessing a Markov blanket were blanket states (i.e., active and sensory states) separate internal states from external states. Our formalization rests on how the metabolic rates of the biosphere (i.e., internal states) relate vicariously to solar radiation at the Earth’s surface (i.e., external states), through the changes in greenhouse and albedo effects (i.e. active states) and ocean-driven global temperature changes (i.e. sensory states). Describing the interaction between the metabolic rates and solar radiation as climatic states—via a Markov blanket—amounts to describing the dynamics of the internal states as actively inferring external states. This underwrites climatic non-equilibrium steady-state through variational free energy minimization—and thus a form of Earth resilience, through active inference at the planetary scale.

References

Friston, K., 2013. Life as we know it. Journal of the Royal Society Interface, 10(86), p.20130475.

Parr, T., Da Costa, L. and Friston, K., 2019. Markov blankets, information geometry and stochastic thermodynamics. Philosophical Transactions of the Royal Society A, 378(2164), p.20190159.

Rubin, S., Parr, T., Da Costa, L. and Friston, K., 2020. Future climates: Markov blankets and active inference in the biosphere. Journal of the Royal Society Interface, 17(172), p.20200503.
The prevalence of meteoric-sulphuric particles within the stratospheric aerosol layer
Authors: Mann Graham , Brooke James , Sengupta Kamalika , Marshall Lauren , Dhomse Sandip , Feng Wuhu , Carslaw Ken , Bardeen Charles , Bellouin Nicolas , Dalvi Mohit , Johnson Colin , Abraham Luke , Remy Samuel , Huijnen Vincent , Chabrillat Simon , Kipling Zak , Deshler Terry , Thomason Larry
Published: March 2021

The widespread presence of meteoric smoke particles (MSPs) within a distinct class of stratospheric aerosol particles has become clear from in-situ measurements in the Arctic, Antarctic and at mid-latitudes.
 
We apply an adapted version of the interactive stratosphere aerosol configuration of the composition-climate model UM-UKCA, to predict the global distribution of meteoric-sulphuric particles nucleated heterogeneously on MSP cores. We compare the UM-UKCA results to new MSP-sulphuric simulations with the European stratosphere-troposphere chemistry-aerosol modelling system IFS-CB05-BASCOE-GLOMAP.

The simulations show a strong seasonal cycle in meteoric-sulphuric particle abundance results from the winter-time source of MSPs transported down into the stratosphere in the polar vortex. Coagulation during downward transport sees high latitude MSP concentrations reduce from ~500 per cm3 at 40km to ~20 per cm3 at 25km, the uppermost extent of the stratospheric aerosol particle layer (the Junge layer).
 
Once within the Junge layer's supersaturated environment, meteoric-sulphuric particles form readily on the MSP cores, growing to 50-70nm dry-diameter (Dp) at 20-25km. Further inter-particle coagulation between these non-volatile particles reduces their number to 1-5 per cc at 15-20km, particle sizes there larger, at Dp ~100nm.

The model predicts meteoric-sulphurics in high-latitude winter comprise >90% of Dp>10nm particles above 25km, reducing to ~40% at 20km, and ~10% at 15km.
 
These non-volatile particle fractions are slightly less than measured from high-altitude aircraft in the lowermost Arctic stratosphere (Curtius et al., 2005; Weigel et al., 2014), and consistent with mid-latitude aircraft measurements of lower stratospheric aerosol composition (Murphy et al., 1998), total particle concentrations  also matching in-situ balloon measurements from Wyoming (Campbell and Deshler, 2014).
 
The MSP-sulphuric interactions also improve agreement with SAGE-II observed stratospheric aerosol extinction in the quiescent 1998-2002 period. 
 
Simulations with a factor-8-elevated MSP input form more Dp>10nm meteoric-sulphurics, but the increased number sees fewer growing to Dp ~100nm, the increased MSPs reducing the stratospheric aerosol layer’s light extinction.
Temporal and spatial dynamic of suspended sediments fluxes and sources and morphological evolution of the bed in the middle Loire river
Authors: Belbal Brahim Hichem , Goutal Nicole , Antoine Germain , Cerdan Olivier
Published: March 2021

The middle Loire riverbed, after its confluence with Allier, is characterised by a morphology of alternate bars more or less vegetated and possesses riverbank flood protections. The suspended particulate matter (SPM) fluxes are therefore originated from these two catchment areas that drain the eastern and southern parts of the Massif Central. The temporal dynamics of the SPM fluxes are very variable, both on an interannual scale and on the scale of a flood event. Furthermore, SPM fluxes also present high spatial heterogeneities as they are governed by complex processes of production (erosion) and transfer (storage/remobilisation). The Loire river plays an important role in supporting the French energy production by providing cooling water to several Nuclear Power Plants (NPP). However, the cooling systems of the NPPs on the middle Loire are exposed to the risk of silting. In order to ensure a safe management of water intakes and prevent the industrial risks arising from sediment transport, it is therefore imperative to understand the spatio-temporal dynamic of sediment production and transfer.

In this context, the objective of this thesis work is to provide keys to improve sediment management of the river between the two NPPs of Belleville and Dampierre. In a first place, the river flow and SPM data available at the upstream NPP of Belleville will be analysed in order to understand the temporal variations of the incoming SPM fluxes. In a second phase, a soil erosion and hydrological model will be implemented to understand the production processes in the upstream catchments. This second part will allow to determine the interactions of the SPM inputs in the river with the morphodynamics of the bed of the Loire between the two stations. We will present the methodology that has been designed to apprehend these two phases and the first results of the river SPM temporal dynamic at the Belleville NPP station.