bluuebunny/crossref_metadata_2025 huggingface dataset:
@Involcan communication strategies on the 2021 Cumbre Vieja eruption: Of do´s, don´ts, trolls and other fantastic beasts
Authors: Calvo David , Asensio-Ramos María , Hernández Pedro A. , D’Auria Luca , Pankhurst Matthew J. , Pérez Nemesio M. , Rodríguez Fátima , Padrón Eleazar , Padilla Germán D. , Barrancos José , Coldwell Berverly C. , Leal VIctoria
Published: March 2022

The 2021 Cumbre Vieja eruption has provided powerful insights not only on the pure research field, but as well on the communication side. From INVOLCAN we´ve developed a clear strategy on how to communicate what was going on, and about the role of science on this eruption. But there is as well a long road to let the different audiences understand the ultimate goal of an institutional profile, that is telling about science and nothing else related to the drama lived by the population. That strategy led us to show anything but science, discarding tons of footage of destruction of infrastructure and properties.

Through the eruption our Twitter and Facebook profiles published the same content, with a clear divergence on the output. While Facebook followers remained almost stagnant all over the 3 months period, the Twitter account skyrocketed to a +-5000% increase on followers, and almost 100M tweet impressions. We focused on working on a single profile rather than in personal profiles of researchers, where part of the message and the influence can be lost in time

All our graphic material was released as public domain, what resulted in hundreds of INVOLCAN TV hours, and led to hundreds of interviews on media from anywhere in the world. The impact of the INVOLCAN brand is literally unaccountable and we believe strengthens the Institute reputation all over.

But we have discovered some flaws as well on the “relationship” established between the “speaker” (INVOLCAN) and the “audience”. As massive attention was driven to the INVOLCAN account, the number of trolls and eccentric characters emerged. This is a well-known behaviour on social media, but never happened before to us on that scale.

A clear ignorance of the objectives of INVOLCAN may explain part of some feedback received, which perhaps did not understand well that INVOLCAN was not responsible for emergency tasks such as evacuations, or that it was not responsible for showing the destruction of private property or that at least it wasn't our job.

But there is still an important part of the work to be done, insofar as it is exhausting to see the proliferation of "experts" capable of demanding information that does not make any sense to the population or that directly accused of hiding information.

There is a long way to go in the world of social networks, and this eruption, the same as that of the COIVD-19 pandemic, has revealed the multiple menaces that threaten science lurking in the shadows, which may end up losing its voice in a tower of Babylon where anyone thinks they know the language of volcanoes
Multi-scale modelling of ice fracture patterns on the surface of Europa using computationally derived tidal boundary conditions
Authors: Walding John , Paluszny Adriana
Published: March 2022

The smallest of Jupiter’s Galilean satellites, Europa has one of the smoothest surfaces of our solar system. This is due to the comparative youth of its ice crust which is believed to resurface over time. This ice crust is observed to be crisscrossed with a multitude of linae, thought to be large-scale fractures, as well as dotted with numerous regions of lenticulae and chaos. Tidal stresses on Europa are modelled according to Wahr (2009) and are evaluated over periods of 1e3-1e6 years. The nucleation, growth and interaction of fractures is modelled using a three-dimensional finite element-based fracture simulator which assumes that the material is linear, isotropic and homogeneous. Other material properties are drawn from Selvans (2009). Nucleation of fractures is assumed to occur only in tension, and sub-scale nucleation modelled by a damage criterion models the weakening of the ice matrix. Stress intensity factors at the fracture tips are computed with the displacement correlation method. Fracture growth is modelled geometrically as a function of the accumulation of stresses on the fracture tips. The simulator evaluates how tidal stresses are expected to induce the nucleation and growth of fractures on the surface of Europa. Nucleation and growth are modelled in two regions, an equatorial region and a sub-polar region, representative of deformation scenarios on the satellite surface. The simulation runs at two different scales. Tidal forces are computed at the satellite scale using Wahr (2009). These are applied as boundary conditions of smaller scale 100km x 100km x 20km cuboidal regions, in which the nucleation and growth of fractures is modelled. Within each region, a number of three dimensional non-planar fractures grow and interact. Resulting patterns are compared against observational data.
Assimilation of historical and paleomagnetic data into dynamo models - reanalysis and predictions of the geomagnetic field
Authors: Sanchez Sabrina , Fournier Alexandre
Published: March 2022

The Earth’s magnetic field displays a rich spectrum of variations spanning from a few months to millennia. Decadal to centennial variations, often called secular variation (SV), are generated by induction due to convective motions of the Earth’s liquid core. They are at the heart of the current displacements of the South Atlantic Anomaly (SAA), decrease of the axial dipole and the rapid acceleration of the North magnetic pole. Although modern satellite and observatory measurements only span the past century, historical records can improve our knowledge of the dynamics causing the SV for the past 500 years and paleomagnetic data for the past millennia. Focusing on the last millennium, we attempt at reconstructing the magnetic field using 3D dynamo simulations as background models and combining them with historical and paleomagnetic data through a Data Assimilation (DA) framework. We use an Ensemble Kalman Filter and explore covariance localization methods that can allow both for stability and small ensemble sizes. We also explore the impact of the underlying dynamo model characteristics in reconstructing core flows and magnetic structures both in synthetic and real DA scenarios. Finally, we aim at presenting a reanalysis of the dynamo state over the past millennium as well as predictions for the next one, with focus on the SAA, dipole evolution and magnetic pole trajectories. 
Numerical and experimental investigation of crack propagation regimes in large-scale snow fracture experiments
Authors: Gregoire Bobillier , Bastian Bergfeld , Johan Gaume , Alec van Herwijnen , Jürg Schweizer
Published: March 2022

Dry-snow slab avalanches are the main cause of avalanche fatalities in mountainous regions. Their release is a multi-scale process which starts with the formation of a localized failure in a highly porous weak snow layer underlying a cohesive snow slab, followed by rapid crack propagation within the weak layer. Finally, a tensile fracture through the slab leads to its detachment. The dynamic process of crack propagation, which affects the size of avalanche release zones, is still rather poorly understood. To shed more light on this crucial process, we performed a series of flat field fracture mechanical experiments, up to ten meters long, over a period of 10 weeks from January to March 2019. These experiments were analyzed using digital image correlation to derive high-resolution displacement fields to compute dynamic crack propagation metrics. We then used a 3D discrete element method (DEM) to numerically simulate these experiments to investigate the micro-mechanics. Both in the experiments and in the simulations, we observed a stationary regime after several meters of crack propagation. The DEM simulations showed that in this regime crack propagation is driven by compressive stresses. A parametric DEM study showed that the elastic moduli of the slab and weak layer, as well as weak layer shear strength, are key variables affecting crack propagation. Our results also highlight that these mechanical parameters influence the propagation distance required to attain the steady-state regime. Finally, DEM simulations on steep slopes showed the emergence of a so-called supershear crack propagation regime, driven by shear stresses, in which crack propagation velocity becomes intersonic. These simulations were confirmed by preliminary experimental results obtained on a steep slope. Our experimental and numerical datasets provide unique insight into the dynamics of crack propagation and lay the foundation for comprehensive studies on the influence of snowpack mechanical properties on the fundamental processes of slab avalanche release.
Investigations of the effects of anthropogenic stratospheric ozone on tropospheric OH
Authors: Satitkovitchai Khompat , Ruhnke Roland
Published: March 2022

The oxidation capacity or self-cleaning in the troposphere is mainly controlled by the existence of the OH radical. The photolysis of ozone into O(1D) and the subsequent reaction with H2O is the primary OH production, which is thus tightly related to the local solar UV actinic flux and hence the overhead ozone column. Globally, the main destruction of OH occurs by the reaction with the greenhouse methane, which lifetime itself is controlled by the concentration of the OH radical. 
In order to improve our understanding of the effects of anthropogenic changes of stratospheric ozone on the oxidation of the greenhouse gas methane, we perform calculations within the ICON-ART framework and report results of long-term simulations with two model configurations concerning stratospheric ozone: a) without interactive ozone, and b) with linearized interactive ozone schemes. The simulations also include a simplified OH chemistry scheme and the CloudJ scheme for the calculation of photolysis rates. With this chemical configurations of ICON-ART two long-term simulations are performed, one AMIP type simulation and one with increased temperatures in the troposphere by 4 K seen by the chemistry. This set of simulations allows to investigate whether the main influence of stratospheric ozone changes on tropospheric oxidation capacity and hence on the lifetime of CH4 is due to changes in the actinic UV flux reaching the troposphere or to tropospheric warming.
Applying Biodiversity Net Gain to solar parks in the UK
Authors: Remazeilles Adèle , Montag Hannah , Carvalho Fabio , Parker Guy
Published: March 2022

Biodiversity Net Gain (BNG) is defined in the UK as ‘development that leaves biodiversity in a better state than before’ and involves an approach where land developers work with local governments, wildlife groups, landowners and other stakeholders in order to support local priorities for nature conservation. The Environment Act 2021 will set out a minimum 10% biodiversity net gain to be mandatory for most land developments and the gain will need to be calculated using the Natural England Biodiversity Metric. The terrestrial habitats listed within the Biodiversity Metric are based on the UK Habitat Classification system (UK Hab).

Solar park developments usually achieve high gains in biodiversity as they commonly lead to intensive arable land or improved grassland being restored to permanent grassland; further enhancements may include sowing of wildflower seed and application of conservation grazing/cutting. However, debate remains regarding classification of proposed habitat within solar parks, in particular, the shaded habitat beneath the panels. We argue that rather than this area being regarded as “lost” habitat, our data show that a variety of plant species can thrive. However, this varies from site to site and is dependent on the vegetation management regime implemented within the site. Site management varies from conservation grazed to intensively grazed, to completely unmanaged, to cut throughout every month to once every three years or with occasional shade / access strips. This extends to treatment of injurious weeds with some non-chemical treatments to other sites which are blanket sprayed with a glyphosate herbicide.

A data set of 30 operational solar parks which were monitored in 2020 were selected and a total of 523 botanical quadrats analysed in order to characterise the vegetation within solar parks (including beneath the panels) in terms of species composition and other UK Habitat Classification criteria such as habitat condition.

These results will be used to provide formal guidance for calculating BNG on solar farms for the solar industry and planning authorities. The proposed approach is being developed with input from Natural England, UK Hab and Solar Energy UK.

 
Challenges and approaches in transdisciplinary climate change adaptation projects
Authors: Harrs Jan-Albrecht , Laranjeira Kevin
Published: March 2022

Climate risks and the appropriate climate change adaptation (CCA) strategies and solutions are highly localized, as they are dependent on the local climate signal, normative assessments on associated risks and the capacities and motivation of municipalities to plan and implement adaptive measures. Research projects trying to explore and pilot applied local solutions therefore need to co-develop recommendations with local practitioners and stakeholders.

Even though a diverse landscape of climate information (CI) is already available and many municipalities know which risk they may face, knowledge and skills on how to interpret, apply and integrate this information in adaptation action is regarded as necessary. Different, albeit non-representative surveys among municipalities in Germany show that more cities are engaging in developing concepts and strategies (Hasse & Willen, 2018; Hagelstange et al., 2021; Handschuh et al., 2020), but that more practice-oriented information on how to identify regional and local vulnerabilities, evaluate efficient adaptive measures, and identify and build up adaptive capacities is needed (Handschuh et al., 2020; Kahlenborn et al., 2021; BBSR, 2016).

Based on an extensive literature analysis of journal articles, research project reports and strategic policy document as well as the experience of accompanying six transdisciplinary research projects, the following categorization of challenges will be presented:

Governance

Adaptive capacities

Integrative assessment of adaptive measures

Climate model data and information

Transdisciplinary work in applied research projects

Drawing on insights on the challenges, a list of recommendations for increasing the use-value of climate information and knowledge for CCA in municipalities is outlined. Tackling these five challenges through co-creating and inserting CI and services into municipal procedures and systems can then address the “last mile problem” (Celliers et al., 2021) of CI and support the lagging implementation of CCA.

In order to conduct impactful transdisciplinary research projects, the specific governance context of municipalities needs to be explored. A survey shows that spatial planning not environmental departments implement most CCA measures (EEA, 2020), whereas planning often lacks climate awareness (Skelton, 2020), signifying the need for cross-departmental approaches. Likewise, the understanding and possible usages of CI needs to be conveyed through appropriate transdisciplinary methods.    
Designing Nature-based Solutions in a Participatory Way: Usability of Tools for Water Professionals
Authors: Bogatinoska Borjana , Lansu Angelique , Huitema Dave , Hugé Jean , Dekker Stefan
Published: March 2022

Participatory processes provide opportunities for stakeholders such as: scientists, policy makers and citizens to meet, exchange information, deliberate and share values. The artefacts through which the water professionals (scientists and policy makers) and the other stakeholders can enable these participatory processes are defined as tools. There is a diversity of rapidly evolving tools for supporting the process of designing nature-based solutions (NbS) together with the stakeholders (participatory designing). This, however, requires a systematic and informed selection to facilitate the adequate choice of tool, aligned to the requirements and context of the water professionals but also the stakeholders. Despite this, there is still little progress and knowledge accumulation over preferred tools. Moreover, while tailored participatory tools could facilitate and accelerate the design process of NbS, a comprehensive mapping of their availability and capacity to respond to the values, requirements and needs of the stakeholders is still missing.

Consequently, in this research, we propose a stepwise framework for the use of tools as support in three interconnected processes: i) tools used for co-designing NbS with stakeholders - co-creation tools, ii) tools used for defining the hydro-meteorological hazards (HMH) and its effects with stakeholders – knowledge tools and iii) tools used for co-implementing the transition towards NbS – transition tools. We then test this stepwise framework in six brook catchments spread in four countries: the Netherlands, Belgium, France and the United Kingdom. The stepwise framework is designed in the following order: tool collection and selection; classification; grading and mapping. We are content that this stepwise framework could show how the water professionals, could make an informed selection and decision on the most suitable tool, based on the usability index of the tool for the specific stakeholder groups and the following criteria: tool category, objective of the tool, the required decision making process stage, the type of stakeholders, and the practical requirements (time, budget, number of participants).

Therefore we designed and tested a framework that allows the water professionals to make a decision on which tool/s could be best used based on their usability but also in terms of their characteristics analysed and described from the water professionals/practitioners themselves. What further discussion on this framework might entail is regarding the trends that we notice in the Co-Adapt project, the limitations and what happens after the tool or suite of tools is applied based on actual field experiences.

 
Designing rapid impact assessments for Switzerland
Authors: Marti Michèle , Dallo Irina
Published: March 2022

Immediately after the shaking of an earthquake has stopped, people want to know what has happened. This concern is not only sensational; those affected seek for advice on what to do next, want additional information they like to share it with their friends and family. This is also true for first responders, who welcome every available insight to plan their emergency response. Rapid impact assessments, automatically generated after an event to locate the affected area and estimate the impact of a specific earthquake in terms of human, infrastructure, and economic losses, can provide such information. Therewith, the information rapid impact assessments contain is of interest for professionals with and without a specific expertise in earthquake risk management, the media, and the interested public. To make use and take meaningful decisions based on this information, rapid impact assessments must be well accessible, clearly structured, useful, and understandable, and meet the needs of different user groups. Based on primary results of the first seismic risk model for Switzerland, we tested rapid impact assessments outputs designed following the state of the art in risk communication. From the feedback of different user groups, we derived recommendations on how to best design useful rapid impact assessments for Switzerland.
Governance and science implications of low environmental impact outdoors solar radiation management experiments 
Authors: Futerman Gideon , Janssens Martin , de Vries Iris , Dykema John , Parker Andy , Hunt Hugh
Published: March 2022

There are many uncertainties surrounding solar radiation management (SRM), which cannot all be quantified and reduced using models, laboratory experiments or observations of natural analogs such as volcanic eruptions, ship tracks, or dust storms. While there is broad consensus both in- and outside the scientific community that better understanding of the climate system is beneficial to policy makers and society, the value of improved knowledge of SRM has been highly controversial. Yet, it is evident that SRM research can contribute to quantifying and reducing important uncertainties pertaining to fundamental knowledge on the workings of the Earth system, while also providing essential specific knowledge on positive and negative impacts of SRM to inform future decisions.

In 2016, a group of SRM experts gathered at the Institute for advanced sustainability studies in Potsdam for a workshop to formulate a set of low environmental impact SRM experiment proposals. We present these as a non-exhaustive set of possible experiments with no measurable environmental side effects that could provide valuable information that cannot be obtained from models or lab experiments. Both perturbative and non-perturbative experiments are proposed for different SRM methods including marine cloud brightening, stratospheric aerosol injection and cirrus cloud thinning.

It was found that in the time period between 2016 and now several of the research questions addressed in the experiment proposals have been answered by unrelated experimental environmental science studies, whereas no experimental studies have been carried out in the context of SRM. This finding shows that there is significant overlap in high priority research questions and outcomes of non-SRM and SRM environmental research. In addition, it shows that non-controversial environmental science experiments can provide similar SRM-relevant knowledge as dedicated SRM-experiments. Given that one of the main arguments against SRM research is the potential danger of the acquired knowledge, the finding that obtained knowledge of non-SRM and SRM experiments can be similar raises the question which effect the declared relationship to SRM on outdoors research proposal review and regulation should be.
The formation of space leaders in streamer coronae of negative leaders
Authors: Köhn Christoph , Babich Leonid , Kutsyk Igor , Bochkov Evgeniǐ , Neubert Torsten
Published: March 2022

Negative lightning leaders, which are associated with the production of terrestrial gamma-ray flashes, prolonged X- and gamma-ray glows and neutron beams, move in a step-wise manner when the original leader channel connects to the hot, highly conductive space leader forming ahead of the leader tip. However, details about the formation and heating of the space leader, and thus of the leader stepping process, are still unknown. Here, we present a novel mechanism on the origin of space leaders: After streamer coronae have formed ahead of the leader tip, plasma chemistry and heating turn a selection of the corona streamers into a highly-conductive region. Further heating subsequently allows for the inception of secondary streamer coronae at the vertices of the conductive region, which continue to heat the already heated plasma filament, finally translating into the hot and conductive space leader. We simulate the evolution of the electric field and the associated plasma chemistry in single streamer channels and present the temporal evolution of the electron density and the electric field as well as of the temperature increase and the conductivity. We find that one streamer alone cannot be heated sufficiently towards a hot space leader, but that the inception and evolution of branching streamer coronae from this initial streamer are necessary for further heating.
Towards a comprehensive High Resolution 3D P- and S-Wave Velocity Model for the Alpine Mountain Chain using Local Earthquake Data
Authors: Braszus Benedikt , Rietbrock Andreas , Haberland Christian
Published: March 2022

Seismic data availability and automated picking algorithms drastically improved in the European Alps since the last orogen wide crustal P-wave velocity model was compiled by Diehl et al. (2009). Especially, the abundant seismic data recorded by the AlpArray Seimic Network (AASN) which was in operation from 2015-2021 provides a unique high resolution seismic data set. The aim of our project therefore is to create a comprehensive 3D P- and S-wave crustal velocity model for the European Alpine region using Local Earthquake Tomography (LET). Such a model is not only needed to sharpen high resolution teleseismic tomography studies imaging subducted slabs but also to relate surface structures to mountain building processes in the mantle.
To achieve this aim precise onset times of seismic crustal phases are needed. Here we show our first results of automatic onset time determination obtained through the deep-neural-network PhaseNet. When compared to catalogues of manual travel time picks, we find its performance as accurate as a human analyst's. This confirms the transferability of machine learning approaches to our area and data set.
The large amount of evenly distributed seismic stations yields up to a total of 720 P and S arrival picks with epicentral distances up to 700km for events with ML > 3.5. Earthquakes with magnitudes of ML=2.5 are generally detectable for epicentral distances up to at least 200km and contribute approximately 200-300 arrivals per event.
As a first step towards a 3D model we present a thorough analysis of the consistency of the automatically determined arrival times, which facilitates a reliable removal of outliers. 
Furthermore, we show visualizations of our preliminary tomography model and its resolution.
Navigation of micro-swimmers in steady flow: the importance of symmetries
Authors: Mehlig Bernhard
Published: March 2022

Marine micro-organisms must cope with complex flow patterns and even turbulence as they navigate the ocean. To survive they must avoid predation and find efficient energy sources. A major difficulty in analysing possible survival strategies is that the time series of environmental cues in non-linear flow is complex, and that it depends on the decisions taken by the organism. One way of determining and evaluating optimal strategies is reinforcement learning. In a proof-of-principle study, Colabrese et al. [Phys. Rev. Lett. (2017)] used this method to find out how a micro-swimmer in a vortex flow can navigate towards the surface as quickly as possible, given a fixed swimming speed.  The swimmer measured its instantaneous swimming direction and the local flow vorticity in the laboratory frame, and reacted to these cues by swimming either left, right, up, or down. However, usually a motile micro-organism measures the local flow rather than global information, and it can only react in relation to the local flow, because in general it cannot access global information (such as up or down in the laboratory frame). Here we analyse optimal strategies with local signals and actions that do not refer to the laboratory frame. We demonstrate that symmetry-breaking is required to find such strategies. Using reinforcement learning we analyse the emerging  strategies for different sets of environmental cues that micro-organisms are known to measure. This talk is based on "Navigation of micro-swimmers in steady flow: the importance of symmetries" by Jingran Qiu, [Opens in a new win Navid Mousavi, Kristian Gustavsson[Opens in a new window], Chunxiao Xu, Bernhard Mehlig, and Lihao Zhao, Journal of Fluid Mechanics 932, A10. doi:10.1017/jfm.2021.978
Impact of trends in historical surface roughness over Europe on extra-tropical windstorms in CMIP6 
Authors: Schuster Mareike , Raddatz Thomas , Ulbrich Uwe
Published: March 2022

Extratropical windstorms are amongst the highest rated perils for the European continent. Extreme wind speeds of these synoptic scale systems occur primarily in the winter season and often cause damage to buildings, forests and infrastructure, and thus can have large socio-economic impacts.

In our studies of extratropical windstorms in the CMIP6 model ensemble, we found remarkable trends of opposite sign in the wind speed during the historical period. More specifically, we found a continuous increase in the surface wind speed in the early historical period between 1850 and 1920, and an even stronger decrease thereafter until the present.

In a case study with one of the models (MPI-ESM) we found that the trends in the wind speed relate to a trend of opposite sign in the roughness length, thus the wind speed increases in eras with a decrease in the surface roughness (and tree fraction) and vice versa.  While this relationship is expected and physically reasonable, it appears that the interaction of surface parameters with the atmosphere was different in CMIP5 climate models, as there is no comparable reaction of surface wind speeds to the trends in surface parameters (e.g. tree fraction).

Since the historical era serves as the reference for any derived climate change signal, these trends might affect the amplitude of the changes in a future climate and the derived conclusions. Also, state of the art climate change signals regarding storminess might need to be reconsidered with this newly represented land-atmosphere interaction in the models.

We further explore this phenomenon by eliminating the influence of the roughness on the wind speed and investigate the effect that this correction has on the appearance of climate change signals of extratropical windstorms.
On the accurate representation of hydropower systems in large-scale hydrological models
Authors: Galletti Andrea , Avesani Diego , Bellin Alberto , Majone Bruno
Published: March 2022

Natural streamflow of most mountain catchments worldwide is altered as a consequence of hydropower exploitation and other water uses. Hydrological modelling in these watersheds represents a challenging task, as the streamflow alteration caused by hydropower production is linked to operational schedules as well as to geometrical and technical constraints, which are system specific. Key parameters controlling hydropower functioning are difficult to acquire, because protected by producers, hence modelling hydropower systems in large domains often resorts to simplified (and less realistic) approaches, in order to cope with the lack of information. However, the accuracy of the simulations depends critically on the reliability of the simplified assumptions, which varies among the proposed approaches. In this work we analyzed the impact of the simplifications typically introduced in modelling hydropower at the catchment and larger scales by assuming as reference HYPERstreamHS, a coupled hydrological and hydraulic model exploiting the information publicly available on single hydropower systems. We present an application of the proposed framework to the Adige river basin, a large watershed located in the south-eastern portion of the Alps, in which the presence of 39 large hydropower systems characterized by complex infrastructures, 22 of which connected to storage reservoirs, causes significant alterations of streamflow timing and magnitude. We demonstrate the benefit of accurately representing hydropower-related water diversions by analyzing how the model represents the observed streamflows at impacted sites and hydropower production at the regional scale. We also provide insights on how a simplified representation of large hydropower systems can lead to a biased evaluation of streamflow alterations at impacted sections and of hydropower production at several sites. Our results show that the effects of different simplifications that may be adopted in the modelling framework combine in a non-linear manner, thus complicating the overall evaluation of the associated impacts.
Stabilization in the fate of destabilization: Improving the representation of C stabilization when modeling C decomposition in permafrost-affected soils 
Authors: Schröer Cosima , Knoblauch Christian , Beer Christian
Published: March 2022

Permafrost thaw may stimulate microbial degradation of large soil organic carbon (SOC) stocks, releasing greenhouse gases into the atmosphere. Projecting this feedback to the global carbon (C) balance is urgent, but remains highly uncertain, because complex interactions between soil and microbes make it difficult to capture C dynamics accurately in models. How much CO2 will be respired is to a high degree dependent on C stabilization and persistence in the soil. SOC may be adsorbed to minerals and thereby unavailable to microbes. Common land surface models ignore this process, potentially overestimating C release from thawing permafrost.

This study investigates the effect of this stabilization mechanism on the decomposition process by applying a process-orientated model approach. We fit a microbial-explicit model, which includes mineral adsorption, to a four-year dataset of aerobic incubations of soils from the Lena River Delta, Siberia. We compare this model to a more conceptual first-order decay model, and to a version without mineral adsorption.

Preliminary results suggest that the mechanistic representation of mineral adsorption is crucial for extrapolations into the future, to avoid depletion of organic C pools or the introduction of artificially long C residence times.  We further emphasize the importance of long-term incubation studies.
How are the energetics of transverse waves in a coronal loop affected by a transition region?
Authors: Duckenfield Timothy , Pelouze Gabriel , Van Doorsselaere Tom
Published: March 2022

Transverse waves of a coronal loop, also known as kink waves, are commonplace in the solar atmosphere, both in their standing and propagating form. Such waves may be important in the energy + mass cycles of the solar corona. Furthermore, recent numerical studies of coronal loops have shown that the plasma heating from dissipation of these waves is sufficient to overcome radiative cooling. However, the addition of a dense mass reservoir at the end(s) of the loop in the form of a chromosphere and transition region can alter the energetics of the wave and its evolution compared to a purely coronal loop.
In this talk, I will outline current progress in 3D MHD simulations of a solar loop incorporating a chromosphere, transition region and coronal component in a stratified, thermally conducting atmosphere. Transverse waves are induced from a driver in the chromosphere, showing these waves are able to penetrate the transition region. This result is important for the decay-less oscillation regime, in which very small amplitude transverse oscillations are seen to persist for many periods, despite the (presumable) action of damping mechanisms such as resonant absorption. The fact that decay-less oscillations may be driven down in the chromosphere supports the notion that decay-less oscillations are powered from below.
When the loop is sufficiently driven, the motion of the coronal plasma leads to small scales generated from Kelvin Helmholtz instability eddies, and these deformations are regions of enhanced heating. I will discuss the simulation results on how the wave energy is dissipated into heat; the relationship between the driver and the heating; and the extent to which the entire loop is heated, and compare with the purely coronal case. 
Assessing the effects of gravel augmentation on thermal processes in gravel-bed rivers
Authors: Marteau Baptiste , Michel Kristell , Piégay Hervé
Published: March 2022

Gravel augmentation has become common practice to mitigate the effects of decline in upstream sediment supply in gravel-bed rivers. However, functional aspects of river systems such as thermal functions are often left out of rehabilitation monitoring programmes. Despite temperature being a fundamental parameter determining the general health of rivers, a limited number of studies have tested whether gravel augmentation can aid restoring thermal functions. Using airborne thermal infrared (TIR) imagery, this paper explores potential feedbacks through the monitoring of gravel augmentation on 3 rivers in France. To overcome the lack of pre-rehabilitation data, we used hydromorphological indicators within a trajectory-based Before-After-Control-Impact (BACI) framework to assess the success of rehabilitation on thermal functions. This design, combining long-term geomorphic evolution with TIR-based CI strategy, indicated that restoring forms was not sufficient to restore thermal functions. Nonetheless, hydromorphological indices mesures on historical aerial photographs can be used to estimate long-term evolution of groundwater-surface water interactions. We emphasise the benefits of trajectory-based BACI assessment to identify current conditions, understand the past evolution (trajectory) of the system to define the framework within which rehabilitation can objectively be assessed.
Characteristics of the urban CO2 plume from Marseille city in the southern France : variability and sources identification using co-emitted species and isotopic ratios.
Authors: Lelandais Ludovic , Xueref-Remy Irène , Riandet Aurélie , Marvin Dufresne , Stéphane Sauvage , Sanne Pastra , Bert Scheeren , Alexandre Armengaud
Published: March 2022

Urban areas are large sources of greenhouse gases and pollutants. CO2 source apportionment are of prerequisite for defining efficient mitigation strategy to reach the regional goal of carbon neutrality in 2050. It is yet challenging to document especially in a large and complex megacity such as Aix Marseille Metropolis (the 2nd biggest French city).  In the framework of the ANR COoL-AMmetropolis project, this work focuses on assessing the variability and composition of the CO2 urban plume in the Marseille city. Three years of continuous atmospheric measurements and one field campaigns carried on at the Longchamp station in Marseille, south-east of France (43° 18′ 20″ N, 5° 23′ 41″ E) are presented. This station is in an urban environment and is mainly influenced by traffic, residential and industrial emissions (source: ATMOSUD inventory). Beside air quality variables like Carbon dioxide (CO2), methane (CH4), black carbon, particulate matter (PM) chemical composition and nitrogen oxides (NOx) are continuously measured at this station to study the spatio-temporal variability of these compounds. A field campaign of one week in January 2020 has been performed to better infer the sources of CO2. One continuous carbon monoxide instrument and two volatile organic compounds analysers were deployed. Furthermore, about 60 air samples were collected for analysing the isotopic ratio and radiocarbon content of atmospheric CO2. Contributions from anthropogenic fossil fuel emissions and biogenic respiration are quantified. The analysis of the temporal co-variations of CO2 with co-emitted species, enhancement ratios and 13C isotopic ratio provide the identification and the contribution of fossil fuel emissions sectors. These results are also be used to verify regional inventories independently and highlights the main emission sectors contributing to the Marseille city center.
Morphometric fingerprinting of submarine canyon and channel processes revealed by time-lapse bathymetric surveys from the Congo Fan
Authors: Hasenhündl Martin , Blanckaert Koen , Talling Peter , Pope Ed , Heijnen Maarten , Ruffell Sean , Baker Megan , Silva Jacinto Ricardo , Hage Sophie , Simmons Stephen , Heerema Catherina , McGhee Claire , Clare Michael , Cartigny Matthieu
Published: March 2022

Submarine canyons and channels include the largest sediment transport systems on our planet. They are an important transport pathway for sediment, organic carbon, nutrients and pollutants to the deep sea. However, it is challenging to study these submarine locations, especially larger systems on the deep seafloor, and they remain poorly understood. Here we use the first extensive time-lapse bathymetric surveys of the Congo Submarine Fan (offshore West Africa), one of the largest submarine fans in the world. Channel-modifying processes (such as landslides, avulsions and knickpoints) are identified by comparing new high-resolution bathymetric data from 2019 to lower-resolution bathymetric data collected between 1992 and 1998, along a 475 km section of the Congo submarine system. These channel-modifying processes leave a specific fingerprint in morphometric characteristics (e.g., bed slope, width, cross-sectional flow area, sinuosity, levee slope and height) that are automatically extracted with a Matlab script from the bathymetric data. This work has the important implication that the identification of channel-modifying processes can be based on a single bathymetric survey, and does not require repeated surveys. In the upstream part of the Congo Canyon, a re-analysis of bathymetric data collected between 1992 and 1998 reveals a previously unnoticed channel-blocking landslide, which is of similar magnitude to a more recent landslide observed from the repeated surveys with a volume of ~0.4 km³. This observation of additional landslides supports the concept that the upstream canyon is morphologically defined by flank collapses, which can locally block the channel and store material for extended periods of time. In the intermediate channel part of the Congo Fan, avulsions already identified in previous work are demonstrated to leave a specific fingerprint within the morphometric characteristics such as a change in levee slope. In the most distal and youngest part of the Congo submarine channel, upstream migrating knickpoints are dominant and are shown to also leave a specific fingerprint in morphometric characteristics. These findings can underpin efficient searches for submarine canyon and channel processes in other systems, and provide new insights into how turbidity currents flush sediment into the deep-sea.
The Application of Relief Models for Environmental Solutions: Review
Authors: Grinberga Linda , Celms Armands , Sietins Krisjanis , Lidumnieks Toms , Brinkmanis-Brimanis Miks , Luksa Jolanta
Published: March 2022

With the development of remote sensing technologies the application of different geospatial models in research has become increasingly important. Terrain relief is the difference in elevation between the high and low points of a land surface, that is, the change in the height of the ground over the area. Terrain relative relief (or elevation) is the relative difference in elevation between a morphological feature and those features surrounding it (e.g. height difference between a peak and surrounding peaks, a depression and surrounding depressions etc.). Together with terrain morphology, ppland other terrain attributes, it is useful for describing how the terrain affects intertidal and subtidal processes.

 Appropriate decision-making tools are required for urban and rural planning, design and management. The usage of DEM (Digital Elevation Model), DSM (Digital Surface Model) and DTM (Digital Terrain Model) helps researchers and designers to analyse issues connected with drainage, geology, earth crust movements, sound and radio-wave distribution, wind effects, exposure to sun, etc. Analysis of the future scenarios of geospatial models has an essential role in the field of water management and various environmental topics. This research aims to focus on the environmental issues in a context of water quality and hydrology.
An ultra-high-resolution seasonal-scale stalagmite palaeoclimate record from the Yucatán peninsula, spanning the Maya Terminal Classic period.
Authors: James Daniel , Carolin Stacy , Breitenbach Sebastian , Endsley Erin , Gallup Christina , Brenner Mark , Curtis Jason , Rolfe James , Nicolson John , Hodell David
Published: March 2022

It has now been over 25 years since stable isotope data from lake sediment cores was first used to provide quantitative evidence of increased aridity in the Yucatán peninsula during the Maya Terminal Classic period (c.800-1000CE); a time in which Maya civilisation underwent major societal shifts and depopulations, frequently termed the Classic Maya Collapse. While palaeoclimatic evidence of reduced precipitation during the Terminal Classic from sediments and, more recently, speleothems is now plentiful, the degree of uncertainty in their chronology and proxy interpretation has precluded analysis of the precise link between decadal and sub-decadal scale drought events and the abandonment of individual Maya archaeological sites on similar timescales.

We present a sub-seasonal-resolution stable isotope record from the stalagmite Tecoh06-1, from Tzabnah Cave (near Tecoh, Yucatán), which spans 185 years of the Terminal Classic. By utilising a prior visual layer count and milling at varying resolution to yield 10-20 samples per lamina, we here record seasonal-scale annual fluctuations in both δ18O and δ13C. With each lamina confirmed to be annual, we have developed a known-duration record which can be temporally fixed by conventional U/Th dating, greatly reducing the associated degree of chronological uncertainty. This is the first local palaeoclimate dataset to record seasonality through the Terminal Classic, and additionally it replicates a lower-resolution record from the same cave, published by Medina-Elizalde et al. (2010), to a satisfactory degree over the sampled period.

Using this palaeoseasonal record we can now reliably characterise the multiple decadal-scale intervals wherein precipitation remained low year-round. These intervals would have likely been those with the most significant detrimental impact on Maya agriculture and society. 
Anthropogenic Influence on Surface Changes at Olivares Glaciers, Central Chile
Authors: Barandun Martina , Bravo Claudio , Grobety Bernard , Jenk Theo , Fang Ling , Naegeli Kathrin , Rivera Andrés , Cisternas Sebastián , Münster Tatjana , Schwikowski Margit
Published: March 2022

We have investigated the source and role of light absorbing impurities (LAI) deposited on the glaciers of the Olivares catchment, in Central Chile. LAI can considerably darken (lower ice albedo) the glacier surface, enhancing their melting. We combined chemical and mineralogical analyses of surface ice samples with field-based spectral reflectance measurements and laboratory analysis to investigate the nature and properties of LAI on the glacier surface. Using remote sensing-based albedo maps, we upscaled local information to glacier-wide coverage. We then used a model to evaluate the sensitivity of surface mass balance to a change in ice albedo. The across-scale surface sample analysis revealed a history of over half a century of LAI deposition. We found traces of mining residuals in glacier surface samples. The glaciers with highest mass loss in the catchment present enhanced concentrations of surface dust particles with low reflectance properties. Our results indicate that dust particles with strong light-absorbing capacity have been mobilized from anthropogenic sources and deposited on the nearby glacier surfaces, thus lowering their surface reflectance. Large scale assessment from satellite-based observations revealed darkening (ice albedo lowering) at most investigated glacier tongues from 1989 to 2018. Mass balance is sensitive to ice albedo changes. However, we believe that an accelerated winter and spring snow albedo decrease, triggered by surface impurities, might be responsible for the above-average mass balances encountered in this catchment.