bluuebunny/crossref_metadata_2025 huggingface dataset:
Release of microplastics from a bio-based composite after ultraviolet irradiation  
Authors: Niu Zhiyue , Catarino Ana Isabel , Le Gall Maelenn , Curto Marco , Demeyer Elke , Hom Dhakal , Davies Peter , Everaert Gert
Published: March 2022

The dependence on petroleum-based polymers such as polypropylene (PP) has led to a series of environmental issues, including the persistence of microplastic (MP), i.e. plastic particles smaller than 5 mm in diameter, in the global ocean. Polymers made from a natural-sourced feedstock, like polylactic acid (PLA), known as bio-based polymers, are seen as more sustainable alternatives to petroleum-based polymers. However, our knowledge remains limited about their degradation rates and fate in the marine environment. Studies have provided evidence of the release of MP from larger debris under ultraviolet (UV) radiation in laboratory conditions. However, quantitative evidence of MP formation, i.e. observation, identification and enumeration of MPs formed after UV radiation, is limited. Indeed, only a few studies have assessed the disintegration of bio-based polymers and their capacity to form MPs. As part of the Interreg 2 Seas Mers Zeeën project SeaBioComp (seabiocomp.eu), we aim to compare, quantify and characterise the MP formation of a newly developed bio-based composite (i.e. bio-based polymers integrated with synthetic or natural fibres) and a reference petroleum-based polymer during their degradation under UV radiation. To do so, we exposed 3D printed cylinders (1 x 1 x 1 cm) of self-reinforced PLA (SR-PLA) and PP respectively, immersed in natural seawater, to accelerated UV radiation for 1,368 h, simulating about 18 months of natural solar exposure in central Europe. Dark controls (i.e. in sealed vials from the UV) were incubated in the same conditions also for 1,368 h. To identify, characterise and quantify the formed MPs, we used a combination of fluorescent microscopy, infrared technology (μFT-IR) and image analysis. We observed 263 ± 285 PP MPs (> 50 µm) and 14 ± 9 SR-PLA MPs in UV-weathered samples, while 3 ± 4 PP MPs and 7 ± 3 SR-PLA MPs in dark control samples. 1,368 h UV exposure accelerated the MP formation of PP (P < 0.05, Kruskal-Wallis) but not SR-PLA (P = 0.29, Kruskal-Wallis), suggesting that the bio-based composite SR-PLA is more resistant to releasing MPs than the reference petroleum-based polymer. We anticipate that our results will contribute to assessing the sustainability of future bio-based polymers and composites applications and to supporting a transition process to more sustainable plastic materials.
Verification of the performance of reinforced concrete profiles of alpine infrastructure systems assisted by innovative monitoring
Authors: Strauss Alfred , Neuner Hans , Rigler Matthias , Polt Markus , Seywald Christian , Kostjak Victoria , Linzer Finn , Loderer Walter
Published: March 2022

The verification of the structural behaviour of existing structures and its materials characteristics requires the application of tests and monitoring to gather information about the actual response. The comparison of the actual performance and the designed performance enables the verification of the design assumptions in terms of implied loads and materials resistance. In case of non-compliance of the designed with the current performance, the design assumptions need to be updated. The objective of this contribution is to provide a guidance for the verification of the performance of reinforced concrete profiles of alpine infrastructure systems like tunnels assisted by monitoring, testing and material testing.

The application of defined loads to a structure to verify its load carrying capacity is a powerful tool for evaluating existing structures. In particular, in this research different types of load tests are employed depending on the limit state which is being investigated on tunnel profiles, on the other hand, the system responses to validate the structural performance are recorded with monitoring systems innovative in tunnel systems, such as accelerometer arrays, fibre optic sensors, laser distance sensors and digital image correlation system, see also the related paper by Neuner et. al. In these studies we also pay special attention to the capabilities of Digital Image Correlation and Nonlinear Finite Element Analysis. Digital Image Correlation (often referred to as "DIC") is an easy-to-use optical method for measuring deformations on the surface of an object. The method tracks changes in the grayscale pattern in small areas called subsets) during deformation. 

Finally, we will present the process for the implementation and validation of proof loading concepts based on the mentioned monitoring information in order to derive the existing safety level by using advanced digital twin models.  
Optimization and characterization of a differential quantum gravimeter
Authors: Janvier Camille , Ménoret Vincent , Merlet Sébastien , Landragin Arnaud , Pereira dos Santos Franck , Desruelle Bruno
Published: March 2022

Measuring the acceleration of the Earth’s gravity g and the gravity gradient simultaneously and at the same location promises to provide enhanced information about the distribution of underground masses, especially at shallow depths [1]. Quantum sensors relying on Atom Interferometry with laser cooled-atoms [2,3] is a technology of choice to implement such new sensing capability and an industry-grade demonstrator has been recently developed [4] by iXblue.

This Differential Quantum Gravimeter (DQG) has been operational for more than two years and has demonstrated state-of-the-art sensitivity mainly limited by Quantum Projection Noise down to a noise floor at about 40E/sqrt(tau). We will present as well a 21 day long run with the demonstration of a resolution below 1E for the measurement of the vertical gravity gradient (1E = 10-9 s-2 = 0.1 µGal/m) and 0.5 µGal for the measurement of g. Moreover in order to illustrate the potential for mass balance monitoring and gravity survey we will present a proof-of-principle experiment with realistic masses and measurement duration. We will provide insight on an previsional accuracy budget and main biases.

The compactness of the instrument and the field-tested technology [5] on which it is based, allows to consider the deployment of this new sensor in real environment as a future short-term outcome to investigate both spatial and temporal mass balance in the field. Promising case studies will be discussed, as this type of sensor can sense mass changes that are not detected by gravimeters.

[1] G. Pajot, O. de Viron, M. M. Diament, M. F. Lequentrec-Lalancette, V. Mikhailov, GEO-PHYSICS 73, 123 (2008).

[2] R.Geiger, A.Landragin, S.Merlet, F.P.D.Santos, AVS QuantumScience 2, 024702(2020).

[3] V. Ménoret et al., "Gravity measurements below 10−9 g with a transportable absolute quantum gravimeter", Nature Scientific Reports, vol. 8, 12300 (2018)

[4] A compact differential gravimeter at the quantum projection noise limit, to be published in Physical Review A

[5] A.-K. Cooke, C. Champollion, N. Le Moigne, Geoscientific Instrumentation, Methods and

Data Systems Discussions 2020, 1 (2020).
A demonstration of CTBTO’s capability to identify the possible source region of the specific case of DPRK announced tests by conducting a sensitivity study using high-resolution ATM 
Authors: Tipka Anne , Kuśmierczyk-Michulec Jolanta , Schoemaker Robin , Kalinowski Martin
Published: March 2022

Detection of radionuclides released from a nuclear explosion is an essential task mandated by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Atmospheric transport modelling (ATM) identifies either possible source regions for relevant radionuclide observations at anomalous concentrations through the so-called International Monitoring System (IMS) or potential stations for measuring releases from known source locations. This is a well-known methodology for connecting sources and receptors of any substance in the atmosphere. The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) currently investigates the potential advantages of using high-resolution ATM. Past announced underground nuclear tests at the Punggye-ri Nuclear Test Site from the Democratic People’s Republic of Korea (DPRK) are used in this study to scale the CTBTO’s capability to identify IMS stations that might detect a hypothetical release. These events are also used to identify the capability to locate Punggye-ri as the possible source location.

A sensitivity study is presented that demonstrates the CTBTO’s capability to identify Punggye-ri as a possible source region for the relevant radionuclide measurements at IMS stations. The aim is to find the best model set-up from varying combinations of meteorological resolution, regional domain set-up, and physical parameterization. Variations in resolution are accomplished by using first the Lagrangian Particle Dispersion Model FLEXPART, which will be driven by meteorological fields from the European Centre for Medium-Range Weather Forecast (ECMWF) with either 0.5° or 0.1° spatial and 1 h temporal resolution; and second, by using a combination of the Weather Research and Forecasting Model (WRF) and FLEXPART-WRF to scale down to 1 km spatial resolution. The potential accuracy increase is evaluated by using metrics from previous ATM challenges.
Energetic particle emission in two solar flares with open magnetic field
Authors: Browning Philippa , Gordovskyy Mykola
Published: March 2022

Energetic particle populations in the solar corona and in the heliosphere appear to have different characteristics even when produced in the same solar flare. It is not clear what causes this difference: properties of the acceleration region, the large-scale magnetic field configuration in the flare, or particle transport effects, such as scattering. We use a combination of non-linear force-free magnetohydrostatic simulations, magnetohydrodynamic and test-particle modelling to investigate magnetic reconnection, particle acceleration and transport in two solar flares events: an  M-class flare on  June 19th, 2013, and an X-class flare on September 6th, 2011. We show that, although in both events particles are energised at the same locations, the magnetic field structure around the acceleration region results in different characteristics between particle populations precipitating towards the photosphere and those ejected towards the upper corona and the heliosphere. We expect this effect to be ubiquitous when particles are accelerated close to the boundary between open and colsed magnetic fields and, therefore, may be key to solar flares with  substantial particle emission into the heliosphere. Furthermore, this analysis elucidates the mechanisms by which escaping particle populations can be created in flares.
Tropical Atlantic modulation of the ENSO teleconnection to the North Atlantic
Authors: Casselman Jake W. , Jiménez-Esteve Bernat , Domeisen Daniela I.V.
Published: March 2022

The El Niño-Southern Oscillation (ENSO) teleconnection towards the Tropical North Atlantic (TNA) represents a robust response, where sea surface temperatures (SST) are positively correlated with ENSO. Following the peak of TNA SST anomalies (SSTAs) in the decaying phase of ENSO, the TNA can influence the local Walker circulation, creating a Rossby Wave Source (RWS) over the Caribbean region in boreal spring and summer. Additionally, when combined with the Pacific SSTAs, this Walker cell perturbation forms the Pacific-Caribbean Dipole (PCD), acting predominantly in the developing phase of ENSO and impacting the North Atlantic European (NAE) region. However, the influence of the TNA SSTAs on the Caribbean RWS and resulting NAE perturbation in the decaying phase of ENSO remains unclear. Thus, we use a series of sensitivity experiments with a simplified atmospheric general circulation model to determine how the TNA modulates the inter-basin teleconnection and how this modulation can influence the NAE response. We find that the NAE region is modulated by the TNA SSTA and Caribbean region in the boreal spring and summer. In boreal spring, a propagating Rossby wave train modulates the NAE region, while in boreal summer, the influence is nonlinear and tends to strengthen ENSO’s influence in the NAE region. Overall, our analysis presents a deeper understanding of the inter-basin Walker cell interactions in the decaying phase of an ENSO event and the TNA’s modulation of the teleconnection to the NAE region.
Effects of coastal roughness on long wave runup
Authors: Didenkulova Ira , Abdalazeez Ahmed , Dutykh Denys , Denissenko Petr
Published: March 2022

Studies of the influence of coast roughness on run-up height have numerous applications to tsunami problem. It happens when tsunami propagates over the urban area and houses and coastal structures represent roughness elements, which help to dissipate wave energy and reduce maximum tsunami inundation and at the same time can break due to tsunami loading. In this paper we focus on this topic from both points of view and study experimentally and numerically reduction of wave run-up height due to the bed roughness and corresponding wave loading on roughness elements.

Experiments have been performed in a 307 m long, 7 m deep and 5 m wide Large Wave Flume in Hannover, Germany. The experimental setup contained a 251 m long section of the constant depth, which was kept at the depth of h = 3.5 m during all tests, and a 1:6 slope section. A total of 16 wave gauges were mounted along the flume to reconstruct the incident wave field and to study its nonlinear deformation. During the tests, two video cameras and a capacitance probe were used to measure wave run-up on a sloping beach. Two cameras were set up to film the surf zone. One video record was used to calibrate the run-up data measured by the capacitance probe. An additional video record was used to determine the shape of the water surface, which was illuminated by a laser sheet along the direction of wave propagation.

Logs with rectangular 10×10 cm cross-section were used as roughness elements and the force acting on logs was recorded. Two logs were equipped with force transducers; one located at the unperturbed shoreline 272 m and the one located at 276 m mark. Four roughness configurations were considered, with logs every 1 m, 2 m, and 4 m which was compared to the smooth, zero log baseline condition. Waves of different height, period and shape have been used as input signals.

Experimentally shown, that run-up height has a strong non-linear dependence on the amplitude of incident wave and the number of roughness elements. Force acting on the roughness elements is related to the amplitude of the incident wave during the run-up phase and is defined by the flowing down near-slope layer when the bulk of the fluid recedes. At higher wave amplitudes, the average force (total momentum) imposed by roughness elements on the fluid is directed up the slope

Described experiments have been used to validate two numerical models (nondispersive shallow water model and dispersive model based on modified Peregrine equations) and to evaluate the potential of these models to simulate wave attenuation due to sea bed roughness. To model the bottom friction, we used both Manning’s and Chezy’s roughness laws. The results of this work are also discussed.
Forest trees can acquire Phosphorus from atmospheric dust deposition directly via the foliageForest trees can acquire Phosphorus from atmospheric dust deposition directly via the foliage
Authors: Starr Maya , Gross Avner , Klein Tamir
Published: March 2022

P availability to trees is often limited by local environmental soil conditions that increase its fixation to soil minerals. In certain regions, atmospheric P inputs can compensate for low soil P availability. Among atmospheric P sources, desert dust is the most dominant. However, currently, the effects of desert dust on the P nutrition and its uptake mechanisms by forest trees is unknown.  

Here we hypothesize that forest trees which naturally grow on soils with high soil P fixation capacity can acquire P from desert dust deposited on their leaves via direct foliar uptake.

We performed a controlled greenhouse experiment with 3 forest tree species. The trees were applied with desert dust directly upon their foliage. Our findings shows that direct uptake of P from desert dust can be an alternative P uptake pathway for various tree species and highlight that desert dust can serve as an important P source to forest trees.      

 
Combining space gravimetry observations with data from satellite altimetry and high resolution visible imagery to resolve mass changes of endorheic basins and exorheic basins.
Authors: Blazquez Alejandro , Berthier Etienne , Meyssignac Benoit , Longuevergne Laurent , Crétaux Jean-François
Published: March 2022

Continuous monitoring of the Global Terrestrial Water Storage changes (TWS) is challenging because of the large surface of continents and the variety of storage compartments (WCRP, 2018). The only observing system which provides global TWS mass change estimates so far is space gravimetry. Unfortunately, most storage compartments (lakes, groundwater, glaciers…) are too small to be resolved given the current spatial resolution of gravimetry missions. This intrinsic property makes gravimetry-based TWS changes estimates difficult to attribute and to interpret at individual basin scale.

In this context, combining gravimetry-based TWS estimates with other sources of information with higher spatial resolution is a promising strategy. In this study, we combine gravimetry data with independent observations from satellite altimetry and high resolution visible imagery to derive refined estimates of the TWS changes in hydrological basins containing lakes and glaciers (See Data used). The combination consists in including independent observations of glacier (Hugonnet et al., 2021) and lake (Cretaux et al., 2016) mass changes in the conversion process from gravity L2 data to water mass changes data. The combination is done for all regions of the world on a monthly basis.

This approach allows to split properly glacier and TWS changes at interannual to decadal time scales, and derive glacier-free estimates of TWS in the endorheic basins and the exorheic basins. We find that for the period from 2002 to 2020, the total TWS trend of 0.23±0.25 mm SLE/yr is mainly due to a mass loss in endorheic basins TWS of 0.20±0.12 mm SLE/yr. Over the same period, exorheic basins present a non-significative trend of 0.03±0.14 mm SLE/yr. On the contrary, the interannual variability in the TWS change of 4 mm SLE is mainly due to the exorheic basins TWS change.
Characterising near-fault deformation in the Apennines through the use of high-resolution Pleiades optical satellite data
Authors: Elliott Bob
Published: March 2022

Bob Elliott, Ken McCaffrey, Richard Walters (all Durham University), Dave Mackenzie (3vGeomatics), Laura Gregory (Leeds University)

Characterising near-fault deformation can improve understanding of how major co-seismic slip at depth is transferred to the surface. Deformation observed close to the fault scarp can identify where there has been shallow slip deficit, and the role of minor faults adjacent to the main faults as controlling influences in co-seismic slip distribution. However, field work and remote sensing techniques such as InSAR and GNSS are often inefficient or unreliable in characterising near-fault deformation due to exposure and data resolution issues. We use high resolution topographical models from optical satellite data from the Pleiades constellations to help identify the co-seismic deformation associated with the 30th October 2016 Norcia earthquake.  We jointly inverted a total of 11 datasets including Pleiades-derived DEM difference data, InSAR and GNSS (far-field and short baseline)) for slip at depth following the method of Okada (1985). Compared to previous models derived from geodetic datasets, we used a relatively complicated fault geometry set-up in the area covered by the Pleiades datasets. By combining the near-fault input provided by the Pleiades data with far-field data we were able to model near-surface slip as well as slip at depth with a good fit to the Pleiades data, without losing the fit to the far-field data. The results show remarkable detail of slip transfer from the main faults onto minor structures in the hanging wall of the Monte Vettore fault within the top 2 km below the surface. Slip vectors near the surface also display considerable divergence from slip vectors at depth. This research provides valuable insight into the distribution of near-fault co-seismic slip in an area of complex faulting, 
Closed Loop Simulations on Recoverability of Climate-Related Mass Transport Signals in Current and Next-Generation Satellite Gravity Missions
Authors: Schlaak Marius , Pail Roland , Jensen Laura , Eicker Annette
Published: March 2022

Satellite gravity missions are unique observation systems to directly observe mass transport processes in the Earth system. Since 2000, CHAMP, GRACE, GOCE, and GRACE-FO have almost continuously been observing Earth’s mass changes and have improved our understanding of large-scale processes such as the global water cycle, melting of continental ice sheets and mountain glaciers, changes in ocean mass that are closely related to the mass-related component of sea-level rise, which are subtle indicators of climate change, on global to regional scale. The existing observation record of more than two decades is already closing in on the minimum time series of 30 years needed to decouple natural and anthropogenic forcing mechanisms according to the Global Climate Observing System (GCOS).

Next Generation Gravity Missions (NGGMs) are expected to be implemented in the near future to continue the observation record. The Mass-change And Geoscience International Constellation (acronym: MAGIC) is a joint investigation of ESA with NASA’s MCDO study resulting in a jointly accorded Mission Requirements Document (MRD) responding to global user community needs. These NGGM concepts have set high anticipation for enhanced monitoring capabilities of mass transports in the Earth’s system with significantly improved spatial and temporal resolution. They will allow an evaluation of long-term trends within the Terrestrial Water Storage (TWS), which was adopted as a new Essential Climate Variable in 2020.

This study is based on modeled mass transport time series of components of the TWS, obtained from future climate projections until the year 2100 following the shared socio-economic pathway scenario 5-8.5 (SSP5-8.5). It evaluates the recoverability of long-term climate trends, annual amplitude, and phase of the TWS employing closed-loop numerical simulations of different current and NGGM concepts up to a spatial resolution of 250 km (Spherical Harmonic Degree 80). The assumed satellite constellations are GRACE-type in-line single-pair missions and Bender double-pair missions with realistic noise assumptions for the key payload and ocean-tide background model errors. In the interpretation and discussion of the results, special emphasis will be given on the dependence of the length of the measurement time series and the quantification of the robustness of the derived trends, systematic changes, as well as possibilities to improve the trend parameterization.
Dynamo models reproducing the offset dipole of Mercury’s magnetic field
Authors: Kolhey Patrick , Heyner Daniel , Wicht Johannes , Gastine Thomas , Plaschke Ferdinand
Published: March 2022

Since the discovery of Mercury’s peculiar magnetic field it has raised questions about the underlying dynamo process in its fluid core. The global magnetic field at the surface is rather weak compared to other planetary magnetic fields, strongly aligned to the planet's rotation axis and its magnetic equator is shifted towards north. Especially the latter characteristic is difficult to explain using common dynamo model setups. One promising model suggests that a thermal stably stratified layer right underneath the core-mantle boundary is present. As a consequence the magnetic field deep inside the core is efficiently damped by passing through the stably stratified layer due to the skin effect. Additionally, the non-axisymmetric parts of the magnetic field are vanishing, too, such that a dipole dominated magnetic is left at the planet’s surface. In this study we present new direct numerical simulations of the magnetohydrodynamical dynamo problem which include a stably stratified layer on top of the outer core, which can also reproduce the shift of the magnetic equator towards north. We revisit a model configuration for Mercury’s dynamo action, which successfully reproduced the magnetic field features, in which core convection is driven by thermal buoyancy as well as compositional buoyancy (double-diffusive convection). While we find that this model configuration produces Mercury-like magnetic field only in a limited parameter range (Rayleigh and Ekman number), we show that also a simple codensity model is sufficient over a wide parameter range to produce Mercury-like magnetic fields.
The future of Gulf of Bothnia, possible changes on salinity and currents
Authors: Siiriä Simo-Matti , Fredriksson Sam , Haapala Jari , Arneborg Lars
Published: March 2022

Understanding the physical development of the Gulf of Bothnia is vital in estimating the future of the area, both for humans and nature alike. 

In the SmartSea project we have made simulations of future scenarios for the Gulf of Bothnia. We have simulated a historical control period of 1976-2006 with three different downscaled global circulation model forcings, and use these as comparisons for runs made with corresponding model forcings for the years 2006-2100 with RCP 4.5 and RCP 8.5 scenarios. 

In this presentation we analyze the changes in salinity and overturning circulation development within the simulation runs. The overturning circulation is characterized by being divided into the two basins Bothnian Sea and Bothnian Bay divided by the Quarken. The circulation in each of the basins is composed of one estuarine circulation with a cyclonic one superimposed. 

Local changes in salinity within the Gulf of Bothnia are affected by the stratification, changes of current patterns and river inflows, although its general salinity development is largely determined by the changes in the Baltic Proper.

The comparison between our simulation runs demonstrate that small changes in conditions can produce very different salinity trends, as either weaken, or strengthen the general circulation of the GoB. While the general salinity trend over the 2006-2100 period is slightly decreasing, the trend can be on the rise for decades within the simulation.
Atmospheric nonlinearities strong contribution to the skewed ENSO amplitude and phase transition
Authors: Gangiredla Srinivas , Vialard Jérôme , Lengaigne Matthieu , Voldoire Aurore , Izumo Takeshi , Guilyardi Eric
Published: March 2022

ENSO features prominent asymmetries, in terms of amplitude, spatial pattern and phase-transition between warm and cold events. Here we examine the contribution of atmospheric nonlinearities to ENSO asymmetries through a set of forced experiments with the CNRM-CM6 AGCM and the NEMO OGCM. Control experiments can reproduce the major atmospheric and oceanic asymmetries of ENSO, with stronger signals east of the dateline for strong El Niño events, and west of it for strong La Niñas. Ensemble atmospheric experiments forced by observed ENSO SST anomalies and their opposites allow diagnosing asymmetries in air-sea heat and momentum fluxes that are directly attributable to atmospheric nonlinearities. They indicate that atmospheric nonlinearities are largely attributable to nonlinearities in the rainfall-SST relation and act to enhance El Niño atmospheric signals east of the dateline and those of La Niña west of it. An ocean simulation where the non-linear signature of air-sea fluxes is removed from the forcing reveals that asymmetries in the ENSO SST pattern are primarily due to atmospheric nonlinearities, and result in a doubling of eastern Pacific warming during the peak of strong El Niño events and a 33% reduction during that of strong La Niña events. Atmospheric nonlinearities also explain most of the observed prolonged eastern Pacific warming into boreal summer after the peak of strong El Niño events. Atmospheric nonlinearities  also appear to contribute strongly to phase transition asymmetries. They indeed result in stronger, more equatorially focussed zonal wind stress anomalies during strong El Niño events. The resulting enhanced off-equatorial wind stress curl doubles the discharge rate after the peak of strong El Niño events, thereby promoting a more systematic transition  to La Niña through the recharge oscillator mechanism. Overall, these results imply that properly simulating the nonlinear relationship between SST and rainfall in CGCMs is essential to accurately simulate asymmetries in ENSO amplitude, spatial pattern and phase transition. Finally, we discuss the inherent limitations to our two-tier forced approach. 
Towards a “multi-level” sustainability analysis in Pacific-Andes-Amazon transboundary catchments.
Authors: Correa Alicia , Forero Jorge , Mulligan Mark , Codato Daniele
Published: March 2022

Global change has economic, environmental, and social impacts on water, energy, and food resources that threaten the ways of living of several communities across the globe. Moreover, the identification of those impacts at the local level constitutes a fundamental step in the process of designing and implementing proposals for the sustainable management of natural resources. The definition of what sustainability means is another key step in that direction. Within theoretical debates, three concepts have been identified: weak, strong, and super-strong sustainability. The first proposes to understand nature as “natural capital”, which should be treated as any other factor of production and can be exchanged with other forms of capital. The second highlights the existence of “critical natural capitals” that need to be conserved no matter the economic cost. The third, finally, introduces cultural, religious, historical, and ethical considerations, proposing the concept of “natural heritage” as an alternative to “natural capital”.

We propose an analytical framework that integrates those different approaches to sustainability, combining spatial data analysis and participatory dialog with actors from local communities. With this methodology, we aim to identify strategies towards the sustainable management of water, energy, and food resources, in the Pacific-Andes-Amazon altitudinal transects of two transboundary catchments of Ecuador, Colombia, Peru, and Brazil (Mira-Mataje - 11,791km2, and Putumayo - 125,563km2). We used remotely-sensed and globally available datasets alongside the spatially distributed assessment model Co$tingNature, to evaluate the natural capital. Then we quantified the interactions between natural capital, protected areas, and indigenous territories to identify critical areas for protection. Finally, we included the knowledge from leaders of Indigenous (Cofán, Awá, and Kamenzat), Mestizo-peasant, and Afro-descendant communities distributed along the altitudinal transects, regarding their natural heritage, and their perception of the challenges for its sustainable management.

We found a significant overlapping between critical natural capital and ancestral territories of ethnic communities and recognized some key anthropic intensive activities that challenge the conservation of those areas. We also identified the significant role that culture plays in the local communities’ efforts both to defend their territory and to find sustainable practices oriented towards the securing of collective welfare and the conservation of the environmental integrity of their natural heritage.
Deciphering debris flow activity in the lake sediment record of Plansee (Austria, Eastern Alps)
Authors: Kiefer Carolin , Oswald Patrick , Moernaut Jasper , Fabbri Stefano Claudio , Mayr Christoph , Strasser Michael , Krautblatter Michael
Published: March 2022

In many mountain environments worldwide, the number of rainstorms capable of triggering debris flows has significantly increased in the last century. An increase in debris flow frequencies in recent times is often postulated but poorly substantiated due to a lack of continuous records over relevant timescales of environmental forcing, especially in the Alpine environment. In this study, onshore processes and the sediment record of an Alpine lake are assessed to reconstruct debris flow activity. The continuous sedimentation regime in lake Plansee (Tyrol, Austria) provides a long-term archive of natural hazards in a setting of highly connective catchment morphology. In an on- and offshore investigation, we integrate LiDAR data, swath bathymetry and sediment core analyses. Two types of alluvial fan deltas are characterized, which differ in sediment delivery and their geomorphic landforms in the terrestrial and subaquatic realm. In a core transect from one fan delta towards the depocentre, we distinguish turbidites related to debris flows and earthquakes. 138 debris flow events were identified in the 4,000 year sedimentary record. The event chronology reveals four phases of different debris flow recurrence. Here a constant background sedimentation with low debris flow rates contrasts to i) debris flow frequency increases interpreted as post-seismic landscape response and ii) a drastic 7-fold increase in debris flow frequency between the periods ~1520 to 1920 CE and 1920 to 2018 CE. These recently enhanced rates may link to the nearly doubled frequency of heavy rainfall events from 1920 to 2010 CE in the Plansee area. We provide sedimentological evidence for a previous LiDAR-based observation of increased debris flow recurrence at Plansee in the 20th century. These results indicate that variations in debris flow activity are mostly controlled by a few severe earthquakes and by climate forcing.

Kiefer, C., Oswald, P., Moernaut, J., Fabbri, S. C., Mayr, C., Strasser, M., and Krautblatter, M.: A 4000-year debris flow record based on amphibious investigations of fan delta activity in Plansee (Austria, Eastern Alps), Earth Surf. Dynam., 9, 1481-1503, 10.5194/esurf-9-1481-2021, 2021.

 
Back-arc thrusting in the Jakarta basin
Authors: Aribowo Sonny , Husson Laurent , Basile Christophe , Natawidjaja Danny H. , Authemayou Christine , Daryono Mudrik R. , Lorcery Manon
Published: March 2022

The Java subduction megathrust is undoubtedly the source of high magnitude, extremely damaging earthquakes. In the back-arc of the subduction zone, severe earthquakes also affect the northern part of Java. The Jakarta basin lies at the western end of the Java back-arc thrust, which stems on the seismogenic Flores thrust in the east and propagates westward across Java. The tectonic activity of the Java Back-arc Thrust in the Jakarta basin has been overlooked because of its low recurrence time. Yet, historical records reveal that it was destructive, resulting in severe destruction in Bogor and Jakarta. Tracking fault activity in large cities is problematic because the original landscape is often profoundly anthropized and has little to do with its pre-industrial physiography. In the Jakarta basin, this is even more complex owing to the fast Plio-Quaternary sedimentation that conceals the morphotectonic features associated with the fault. We combine geomorphic observations and subsurface data using DEMs and optical imagery, seismic reflection and biostratigraphic well data. At depth, seismic data reveal a partitioned fault network of compressive fault-propagation folds and transpressive flower structures that deform the Plio-Quaternary sedimentary layers of the Jakarta basin and interplay with volcanoes. At the surface, morphological observations in the rims of the basin reveal that several river meanders were abandoned and uplifted hundreds of meters above the current riverbeds above the fault network. In the basin, multiple meter scale waterfalls that we interpret as knickpoints above active faults scar the flat surface of the basin. We conclude that the western end of the Java back-arc thrust fault bears a potentially high risk for the infrastructures of the densely populated province of Jakarta.
Spatiotemporal Variations and Driving Factors of Species Richness in China Based on Satellite-derived Dynamic Habitat Indices
Authors: Wang Yanyu , Wu Wenqiang , Wang Zhige , Shi Zhou
Published: March 2022

The variation of biodiversity in China has attracted extensive interest with the rapid development these years. Comprehending the past and current patterns of biodiversity in China is of significance for development planning and biodiversity management. Satellite data has proved to be a useful tool to characterize the spatial distributions of species on the basis of the species energy hypothesis and hence support biodiversity conservation. The main objectives of this study, therefore, was to evaluate different proxies for annual species richness in China from Moderate Resolution Imaging Spectroradiometer (MODIS) as input for the Dynamic Habitat Indices (DHIs), and to analyze the trend and triggers of variation in DHI for the period 2003 to 2015. We calculated the DHIs (including DHIcum, cumulative productivity; DHImin, minimum productivity; DHIvar, intra-annual variation of productivity) in China at 1-km resolution from vegetation productivity MODIS products (NDVI, EVI, LAI, fPAR and GPP), based on the median of the good observations of all years from the whole MODIS record in both 8- and 16-day composites during the year, and calculated species richness at 10-km resolution from species range maps from the IUCN Red List. The linear relationships between the species richness and different DHIs were evaluated and the best performed DHI was obtained. We further analyzed the long-term trend of the best performed DHI by least squares linear regression analysis and performed partial correlation analysis with annual precipitation, mean temperature and solar radiation, respectively. Generally, we found that all DHIcum and DHImin had high explanatory power for estimating species richness (R2 > 0.6), and the GPP outperformed other indexes. The trend analysis showed that the most regions resulted in an insignificant change while the significant changes had appeared in several areas, like North China Plain and Inner-Mongolia. Our study revealed the spatiotemporal pattern and variation of species richness in China, and is promising for application in biodiversity conservation and policy making.
Coastal retreat doubles previous estimates of Antarctic ice shelf loss
Authors: Greene Chad , Gardner Alex , Schlegel Nicole-Jeanne , Fraser Alexander
Published: March 2022

Ice shelves tend to grow through a steady influx of glacial ice and retreat in discrete calving events that occur on subannual to multidecadal timescales. The impacts of ice shelf calving and retreat are far-reaching, but the evolution of Antarctica’s coastline has not been well characterized, owing to the difficulty of delineating ice fronts in limited satellite data. To create an annual coastline dataset that spans the past quarter century, we combine data from multiple satellite sensors, and we use the known physics of ice flow to constrain ice front positions and fill gaps in the data record. We find that since 1997, Antarctica’s coastlines have retreated by 37,000 km2, led by major calving events from the Ross and Ronne ice shelves in the early 2000s, and sustained by countless loss events from smaller ice shelves ever since. Calving losses total nearly 6000 Gt, which is roughly equivalent to the total mass that has been lost to ice shelf thinning over the same period. Using an ice sheet model, we examine the impacts of observed coastal changes on the buttressing strength of Antarctica’s ice shelves.  
Toxic European Summer Flood – Dispersion of organic pollutants along the Vicht and Inde rivers, Germany
Authors: Bellanova Piero , Schwarzbauer Jan , Reicherter Klaus
Published: March 2022

The 2021 European floods (July 13th–16th, 2021) marked Germany’s deadliest (>180 fatalities) and most costly (>€ 30 billion) natural disaster of the 21st century. In North Rhine-Westphalia (Germany) the floods have caused drastic scenes of destruction along small mountainous river systems, such as the Vicht and Inde rivers. Alongside this destruction stands the release of organic pollutants and the remobilization of sediment-associated old burdens in the former mining area of Stolberg. In a preliminary study 10 samples along the floodplains and urban areas of Vicht and the successive Inde rivers have been collected directly after the flood to determine the pollution concentration, dispersion and potential sources. With this information an assessment of the short-term and long-term environmental risks can be evaluated.

First results show acute enrichment of organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs – petrogenic pollutants), polychlorinated biphenlys (PCBs – old burdens/plasticizers) and linear alkylbenzenes (LABs – sewage). The sewage indicators show their highest release and accumulation in samples taken in the urban areas, and subsequently dilute along the natural floodplain segments. This repeats for at least for Stolberg and Eschweiler, which were flooded by the Vicht and Inde, respectively. Old burdens, such as represented by PCBs, related to historical and present heavy industry in the vicinity to the rivers. The flood caused the remobilization of respective old burdens from contaminated plains and urban sources. Petrogenic markers, especially those of PAHs, have been measured in concentrations of mg/kg, vastly exceeding all environmental guidelines and restrictions. These can also be linked to the flooding of industrial and urban sites (e.g., household oil heating tanks, vehicles).

The wide range of observed pollution and fast dispersion of sediment-associated pollutants can be linked to the highly dynamic nature of this flood. In addition, the multitude of historical (mining, heavy industry) and present sources (e.g., fuels, oil, factory effluents, wastewater), sediment-associated pollutants have been remobilized or acutely released with the flood. This unprecedented 2021 European floods may allow insights into the relationships and interactions between hydrodynamics, sedimentology and pollution during such events.
Data-Unconstrained Modeling and Detection of 9 Individual Partial Ocean Tides of Third-Degree by Terrestrial Gravimetry
Authors: Wziontek Hartmut , Sulzbach Roman , Hart-Davis Michael , Dobslaw Henryk , Scherneck Hans-Georg , Van Camp Michel , Omang Ove Christian Dahl , Antokoletz Ezequiel D. , Voigt Christian , Dettmering Denise , Thomas Maik
Published: March 2022

The Tide-Generating Potential (TGP) of the Moon is not symmetric but asymmetric with respect to the Lunar sub-orbital axis due to its relative proximity compared to astronomical length scales. This asymmetry can be described in the first order by the third-degree of the TGP expanded in Spherical Harmonic functions. Despite the tiny magnitude of this asymmetry (1/60 of the leading, second degree) several corresponding oceanic partial tides were previously detected in both tide gauge and superconducting gravimeter records. 

In this contribution, we present solutions with the data-unconstrained ocean tide model TiME (Sulzbach et al. 2021) for a number of partial tides of the third degree in all relevant tidal bands (long-period to terdiurnal). Tuning the model with the recently compiled TICON-td tide gauge dataset, we find the modelled ocean tide signals to agree at levels over 50 % with oceanographic data. The gravimetric impact of the oceanic load tides on 16 globally distributed gravimeter stations which amounts to only a few nGal is then modelled by 2 approaches: (1) a computation with SPOTL and (2) with an approach constrained by load Love numbers. While the gravity constituents modeled with both approaches are close to identical, comparison to the analysed constituents shows a high agreement between 63% to 80% for the degree-3 components depending on the selected partial tide solution, thereby confirming both the low noise level of state-of-the-art superconducting gravimeter recordings and the applied hydrodynamic modelling. 

By modeling and analyzing for additional degree-3 constituents (resulting in three partial tides in the diurnal, semidiurnal and terdiurnal band), load tide admittance functions of degree-3 can be calculated. We show that third-degree ocean and load tides exhibit a considerable admittance-dispersion that should be considered when estimating load tide contributions of other third-degree partial tides. For example, a larger number of degree-3 tides can be considered for satellite gravity when combining the presented solutions with a linear admittance approach, which might become relevant already for the upcoming MCM/MAGIC constellation currently studied by NASA and ESA.

References:
[1] Sulzbach, R., Dobslaw, H., & Thomas, M. (2021), JGR: Oceans., 126, 1–21, https://doi.org/10.1029/2020JC017097
Exploring coastal dune adaptation through a simplified process-based model
Authors: Costas Susana , Kombiadou Katerina , Roelvink Dano
Published: March 2022

Coastal dunes result from the accumulation of wind-blown sand transferred inland from the beach and trapped by physical barriers such as vegetation. Vegetation also plays an active role on dune growth through the onset of feedbacks with the dune topography and the air flow. All these complexities have been tentatively captured by recent numerical models, which also may help to better understand dune response to disturbances as well as possible evolutionary patterns. Duna is a simplified process-based model, which integrates air flow, sediment transport and vegetation dynamics to reproduce the morphodynamic response along the dune profile. The present work focuses on extending Duna to include the influence of fetch-limited conditions and to accommodate different wind incidence angles by using projected wind-parallel dune profiles.

The performance of the model was assessed by comparing model outputs with wind profile and sedimentation observations from contrasting dune morphologies and environments, showing a good agreement and promising results. Duna was further used to test several hypotheses related to air flow dynamics and topography and to explore sediment transport and accumulation patterns across a series of different dune morphologies, including basic biogeomorphic feedbacks.
Can fully satellite-products-driven simple models account for snow processes in data scarce regions?
Authors: Gyawali Dhiraj Raj , Bárdossy András
Published: March 2022

This study investigates satellite-based information driven snow accounting routines to simulate snow processes in mountainous regimes that are inherently associated with data scarcity. Simple, independent and parsimonious snow accounting routines that are fully driven by remote sensing (RS) information such as the land surface temperatures and snow-cover information along with distributed temperature index-based snow-melt models, are presented. RS based snow-cover distribution does not only provide the crucial information on areal extent of snow, but can also be a highly imperative proxy for the precipitation accumulations in these data scarce regions, as the availability and resolution of the data doesn’t depend on the mountainous terrain. These models are calibrated independently on the snow-cover distribution, can be coupled with any rainfall-runoff models to simulate “snow-processes informed” discharge and are flexible enough to be extended to a wide geographical extent. These models, in addition to simulating the snow accumulation and melt processes, also use the timing of snow appearance and disappearance. This accounting of snow can be inverted to obtain seasonal precipitation estimates in data scarce snow dominated regions, which can be a very crucial information for water resources planning. Specific results pertaining to the validation of the models in Switzerland and southern Germany (ungauged scenario) are shown. 