bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary results of the two seismic sequences in the Vienna Basin in March and April 2021 
Authors: Papí Isaba María del Puy , Lenhardt Wolfgang , Meurers Rita , Apoloner Maria Theresia , Hausmann Helmut , Mattesini Maurizio , Buforn Elisa
Published: March 2022

We present a preliminary analysis of two seismic sequences between March and April 2021, near Neunkirchen and Gloggnitz, about 50 km from Vienna, Austria, and around 15 km apart from each other. Despite the moderate magnitudes, the recent earthquakes in the epicentral region, in the southern part of the Vienna Basin, were felt in the epicentral region and up to a distance of 300 km away. 

The Neunkirchen sequence started on March 11th, 2021. According to the Austrian Seismological Service at ZAMG, the last recorded earthquake occurred on May 12th, 2021. Over 245 earthquakes, with local magnitudes ranging from 0.5 to 4.6, were recorded until mid of May 2021. Out of the 245 earthquakes, 21 were felt by the population (1.8 ≤ ML ≤ 4.6), and two of them (ML4.6 and ML4.4) caused minor damage in the epicentral region. According to the Austrian Seismological Service, the depths of this sequence ranged from 7 to 12 km. 

The Gloggnitz sequence started on April 1st, 2021, and continued until May 8th, 2021. The epicenters of 65 detected earthquakes were located. Four earthquakes were felt, from which two (ML3.6 on April 20th and ML3.8 on April 23rd) caused slight damage. The local magnitudes of this seismic sequence ranged from -0.3 to 3.8; depths varied between 4 and 7 km. 

The relocation of the earthquakes of both sequences was carried out using the NonLinLoc by Lomax et al. (2019). We obtained the ellipse error for all relocated earthquakes. The focal mechanisms of the largest earthquakes were calculated using Seismic Moment-Tensor-Inversion. For the remaining events, a joint fault-plane solution was investigated. Furthermore, we compiled and analyzed the macro-seismic questionnaires of all felt earthquakes in the series and produced intensity maps (EMS-98). We compared the intensity attenuation as a function of distance with the newly available data and derived an Intensity Prediction Equation (IPE) for the region.
Seismoacoustic monitoring of La Palma 2021 volcanic eruption (Canary Islands): first results
Authors: Jurado Maria Jose , Lopez Carmen , Blanco Maria Jose , Lopez Ruben , Meletlidis Stavros , Moure David
Published: March 2022

We present first results on the continuous monitoring of the 2021 La Palma volcanic eruption (Canary Islands, Spain), from September 2021 to December 2021. During the eruption we installed a 8 level 3-component geophone string and 15 m spacing between geophones in Las Manchas within the restricted area and less than 2 km away of the volcanic edifice. The string was installed on the ground surface, in a straight line pointing towards the volcano. The 24 channels were sampled at 250 Hz, and data acquisition was performed in real-time and continuously till the end of the eruption with occasional minor gaps. The resulting seismoacoustic dataset is a sample of elastic energy propagating in both the subsurface and the atmosphere, allowing us to improve our understanding of the eruptive subsurface and subaerial processes. We use these seismoacoustic records to identify and characterize the different phases and signals of the volcanic activity. For the first analysis of the dataset we performed the calculation and graphing of spectrograms during the acquisition. We identify eruptive signals and correlate them with different events that can be directly observed on the basis of frequency content and relative timing. Explosive events like those derived from destruction of conduit plugs and ash-rich plumes emission, ash-rich explosions, volcanic lightning and degassing events are being analysed.

Finally, we study the correlation of seismic and seismoacoustic records for the same event by comparing with seismic data recorded on land stations. Results show that a good correlation exists between seismic and seismo-acoustic data for the main activity observed in the surface: the activity at the various vents and events like episodes of ash emission and bursts, indicating that this methodology can be successfully applied to monitor remote eruptions. Coupled seismoacoustic observations have turned out to be useful because they provide a comprehensive record of subsurface and subaerial eruptive activity.
Experimental approach to measure capillary associated interfacial area using kinetic interface sensitive tracers in a simultaneous two-phase flow
Authors: Abdullah Hiwa , Tatomir Alexandru , Sauter Martin
Published: March 2022

The kinetic interface sensitive (KIS) tracers have been the focus of research in the past decade, as a new, reactive tracer method to estimate the interfacial area between immiscible fluids in porous media. We present here a novel experimental approach to measure the capillary associated fluid-fluid interfacial area using the KIS tracers in simultaneous two-phase flow conditions. The new approach is applied in a sand column filled with glass-beads (d50 = 170µm). Four laboratory experiments are performed in a simultaneous two-phase injection scheme using different fractional flow ratios (Flow rate of wetting phase: total flow rate). The different fractional ratios create different saturations inside the column, which correlate to different fluid-fluid interfacial areas. The new method, introduces also a new analytical method to handle reacted by-product concentration data acquired, different from the KIS tracer method in dynamic conditions. By comparing the results to other established techniques reported in the literature (i.e., interfacial partitioning tracer test and computed micro-tomography) used to measure fluid-fluid interfacial area we observe a good agreement.  The capillary associated interfacial area increases with decreasing wetting saturation until a maximum value, which then drops near the residual saturation. The maximum capillary associated interfacial area occurs at wetting saturation ranges between 0.45 < Sw < 0.6, which is slightly shifted towards the higher wetting saturation when compared to the other techniques. Furthermore, the results are simulated using a Darcy-scale reactive transport multiphase flow in porous media numerical model.
Exploring the effect of mantle composite rheology on surface tectonics and topography
Authors: Arnould Maelis , Rolf Tobias , Manjón-Cabeza Córdoba Antonio
Published: March 2022

Earth’s surface dynamics and topography are tied to the properties and dynamics of mantle flow. In particular, upper mantle rheology controls the coupling between the lithosphere and the asthenosphere, and therefore partly dictates Earth’s surface tectonic behaviour and topographic response to mantle convection (dynamic topography). The presence of seismic anisotropy in the uppermost mantle suggests the existence of mineral lattice-preferred orientation (LPO) caused by the asthenospheric flow. Together with laboratory experiments of mantle rock deformation, this indicates that Earth’s uppermost mantle can deform in a non-Newtonian way, through dislocation creep. Although several studies suggest the potentially significant effect of upper-mantle non-Newtonian rheology on mantle convection (e.g. Schulz et al., 2020) and topography (e.g. Asaadi et al., 2011, Bodur and Rey, 2019), it is usually not considered in whole-mantle models of mantle convection self-generating plate tectonics.

 

Here, we investigate the effects of using a composite rheology (with both diffusion and dislocation creep) on surface tectonics and dynamic topography in 2D-spherical annulus models of mantle convection with plate-like tectonics and continental drift. We systematically vary the amount of dislocation creep by changing the activation volume for dislocation creep and the reference transition stress between diffusion and dislocation creep. We show that for low yield stresses promoting plate-like behavior in diffusion-creep-only models, modeling a composite rheology in the mantle favors more surface mobility while for large yield stresses which still generate plate-like motions in diffusion-creep-only models, a progressive increase in the amount of dislocation creep leads to stagnant-lid convection. We then compare the amplitudes and spatio-temporal distribution of dynamic topography in models with and without dislocation creep, in light of observed Earth present-day residual topography characteristics.

 

References:

Schulz, F., Tosi, N., Plesa, A. C., & Breuer, D. (2020). Stagnant-lid convection with diffusion and dislocation creep rheology: Influence of a non-evolving grain size. Geophysical Journal International, 220(1), 18-36.

Asaadi, N., Ribe, N. M., & Sobouti, F. (2011). Inferring nonlinear mantle rheology from the shape of the Hawaiian swell. Nature, 473(7348), 501-504.

Bodur, Ö. F., & Rey, P. F. (2019). The impact of rheological uncertainty on dynamic topography predictions. Solid Earth, 10(6), 2167-2178.
Flash droughts: bridging the understanding between physical definitions and societal impacts
Authors: Walker David W. , Vergopolan Noemi , Cavalcante Louise , Almagro André , Apurv Tushar , Kingston Daniel G. , Roy Tirthankar , Smith Kelly Helm , Wanders Niko
Published: March 2022

The term ‘flash drought’ has become increasingly prevalent in scientific discourse and research on the topic is growing. The corresponding increase in flash drought publications typically presents definitions, mechanisms, detection and monitoring, and forecasting. However, many aspects of flash droughts are less well understood, such as flash drought impacts, especially the socioeconomic and environmental impacts.

Flash droughts tend to be defined from a hydrometeorological perspective as events of rapid onset, rapid intensification, low precipitation and soil moisture, and high temperature. Yet there are similar, often locally named, phenomena around the world with their own specific characteristics and impacts that could be considered flash droughts. Such events may not match literature or index-specific definitions of flash drought, for example due to their very short duration or anthropogenic drivers. Consequently, they may go undetected or unpredicted in the increasingly common global flash drought products and may not be considered in flash drought research.

We, the co-authors (a sub-section of the Panta Rhei ‘Drought in the Anthropocene’ working group), conducted a survey among peers to collect cases from around the world of alternative names, characteristics and impacts of flash droughts. Many regions were represented in the responses and local nomenclature for flash drought-like events were identified, in particular from Brazil, South Asia, Sub-Saharan Africa and Central America.

Maps of flash drought hotspots based on hydrometeorological indices often do not indicate whether anything adverse was experienced on the ground, or overemphasise occurrence where events are unlikely. Therefore, we utilised the survey findings and subsequent investigations to ‘ground truth’ a flash drought hotspots map. We related hotspots to published case studies of drought impacts or existence of local terms for flash droughts. However, mismatches occurred suggesting there are regions potentially experiencing flash droughts that are either not represented in our survey nor in the literature or there are inaccuracies in flash drought hotspot identification.
Advective trapping in  the flow through composite heterogeneous porous media
Authors: Hidalgo Juan J. , Neuweiler Insa , Dentz Marco
Published: March 2022

We study the mechanisms of advective trapping in composite porous media that consist of circular inclusions of distributed permeability embedded in a high conductivity matrix. Advective trapping occurs when solute enters low velocity regions in the media. Transport is analyzed in terms of breakthrough curves measured at the outlet of the system. The curve's peak behavior depends on the volume fraction occupied by the inclusions, while the tail behavior depends on the distribution of permeability values. In order to quantify the observed behaviors we derive two equivalent upscaled transport models. First, we  derive a Lagrangian trapping model using the continuous time random walk framework that is parameterized in terms of volume fraction and the distribution of conductivites in the inclusions. Second, we establish a non-local partial differential equation for the mobile solute concentration by volume averaging of the microscale transport equation. We show the equivalence between the two models as well as (first-order) multirate mass transfer models. The upscaled approach, parameterized by medium and flow properties captures all features of the observed solute breakthrough curves, and sheds new light on the modeling of advective trapping in heterogeneous media.
Reducing future water stress in the Seewinkel region in Austria: exploring water management opportunities for the sustainable use of the shared groundwater resource.
Authors: Sahu Reetik Kumar , Kahil Taher , Guillaumot Luca , Burek Peter , Hangar-Kopp Susanne , Karabaczek Veronica , Offenzeller Martina , Lindinger Helga
Published: March 2022

Austria is well endowed with water resources where the total water demand consumes only 3% of the total water supply. However, with increased water demand from agriculture, domestic and industrial sectors and increased frequency of high heat and drought occurrences from future climate change, several regions can potentially face high water stress for short periods in a year which is detrimental to the economy and the environment. The Seewinkel region located in eastern Austria is one such case where both agriculture and environment are dependent on a reliable quantity of water to be available throughout the year. Apart from precipitation, additional crop water requirement is satisfied using an irrigation infrastructure. Groundwater which is the sole source of irrigation water in the region is pumped based on the water allocations prescribed to each irrigation cooperative in the region. These allocations currently limit groundwater withdrawals for potentially higher agricultural output and maintain the natural Seewinkel wetland supported by groundwater body. With climate change induced water stress in the future, sufficient water table levels cannot be maintained throughout the year whil​e simultaneously trying to satisfy agricultural and environmental water demand. Our study identifies different cost optimal management strategies to optimally manage the groundwater resources shared between multiple irrigation cooperatives in the region. Some of the strategies include optimal crop-land mix, irrigation technology transitions, building new water supply infrastructure and using financial instruments. Additionally, the study aims to identify the nature of the shared common pool of groundwater to identify the potential of trading water allocation rights between irrigation cooperatives which can lead to efficient water use. The strategies have been identified based on the stakeholder interviews conducted in the region under the WaterStressAT project KR19AC0K17504 funded by the Austrian Climate Research Program twelfth call.
Identification and characterization of vegetation loss during the last 50,000 years in Beringia
Authors: Courtin Jeremy , Alsos Inger , Biskaborn Boris , Diekmann Bernhard , Huang Yongsong , Lammers Youri , Melles Martin , Pestryakova Luidmila , Schulte Luise , Stoof-Leichsenring Kathleen , Herzschuh Ulrike
Published: March 2022

Ongoing climate change causes a global biodiversity loss and species extinction by reducing population size and decreasing genetic diversity. Massive extinction events happened in the past with the Megafauna extinction as the latest example. The Pleistocene-Holocene transition also witnessed the loss of the broadly established steppe-tundra biota, spanning most of Northern Hemisphere during the Pleistocene and supporting Pleistocene megafauna at the time. Understanding past extinction events via the investigation of Quaternary records can strengthen the current methods to forecast the effects of global warming on ecosystems. If loss of other organism groups were proportional to what has been shown for mammals, a large part of the Pleistocene steppe-tundra biota might have gone extinct. However, few example are known. The improved taxonomic resolution and high detectability of sedimentary ancient DNA provide a new tool to explore this. Here, we investigate potential plant taxa loss in the Northern Hemisphere between the late Pleistocene-Holocene transition using sedimentary ancient DNA (sedaDNA) metabarcoding. We summarized data from 500 samples comprising nine lake sediment cores from North-East-Asia and North-America spanning the last 50.000 years. Using patterns of past plant diversity (appearance-disappearance through time), we built communities to detect past taxa non-present in modern databases inferring potential candidates for extinction. Our results suggest that vegetation was resilient until the Pleistocene to Holocene transition and that loss appeared in parallel to the Megafauna extinction. Finally, we characterized this vegetation loss and identified that more specialist taxa contributing less to beta diversity are more sensitive to potential extinction than other taxa. This work holds great potential to reveal new insights into the evolution of the fragile boreal plant communities and the processes leading to extinction of species.
Values and challenges of DInSAR derived velocity estimates for landslide hazard assessment and mapping
Authors: Jacquemart Mylene , Manconi Andrea
Published: March 2022

Deep-seated slope instabilities pose a significant hazard to infrastructure and livelihoods in mountain regions all around the world. Increasingly accesible data from synthetic aperture radar (SAR) satellites, such as ESA’ Copernicus Sentinel-1 mission, offer easier access to displacement data that can be used to detect, delineate, and monitor landslides in mountainous terrain. However, displacement measurements retrieved from differential interferometric processing (DInSAR) can be biased by the terrain geometry, which can lead to an underestimation of the true displacement. In addition, the quality of DInSAR results is highly susceptible to changes of surface geometry and moisture conditions, for example due to snow melt, hillslope erosion, or vegetation changes. Furthermore, the relative nature of DInSAR measurements can lead to underestimation of displacements due to phase aliasing. These factors may severely impact the accuracy of landslide velocities quantification. However, landslide velocities are often directly used in hazard assessment.

 

In Switzerland, mean and maximum landslide velocities are key factors used to assess the hazard intensity of unstable slopes, and thus to determine the slope hazard potential and consequently hazard zonation. The latter has direct implications for land use and land-use planning. In this study, we use two exemplary large deep-seated instabilities at Brienzauls (canton of Grisons) and Spitzer Stein (canton of Bern), both in Switzerland, to showcase the challenges of relying on DInSAR derived velocities for hazard mapping. We attempt to disentangle effects of terrain and orbit geometry on the measurable velocities from those caused by transient changes to surface geometry and conditions, and explore ways by which the value of DInSAR-derived displacement measurements can nevertheless be maximized for hazard zonation mapping. 
High-Resolution Reanalysis of the Mediterranean Sea Biogeochemistry 
Authors: Cossarini Gianpiero , Salon Stefano , Feudalel Laura , Bolzon Giorgio , Coidessa Gianluca , Solidoro Cosimo , Di Biagio Valeria , Amadio Carolina , Lazzari Paolo , Brosich Alberto
Published: March 2022

Ocean reanalyses integrate models and observations to provide a continuous and consistent reconstruction of the past physical and biogeochemical ocean state and variability. We present a reanalysis of the Mediterranean Sea biogeochemistry at a 1/24o resolution developed within the Copernicus Marine Service framework. The reanalysis is based on the Biogeochemical Flux Model (BFM) coupled with a variational data assimilation scheme (3DVarBio) and forced by the NEMO–OceanVar Mediterranean reanalysis and the ERA5 atmospheric reanalysis. Covering the 1999–2021 period, the reanalysis assimilates ESA-CCI satellite chlorophyll data and integrates EMODnet data as initial conditions, in addition to considering World Ocean Atlas data at the Atlantic boundary, CO2 atmospheric observations, and yearly estimates of riverine nutrient inputs.

With the use of multiple observation sources (remote, in situ, and BGC-Argo), the quality of the biogeochemical reanalysis is qualitatively and quantitatively assessed at three validation levels. Results of the first validation-level indicate an overall pretty good reanalysis skill in simulating basin-wide values and variability in the biogeochemical variables, such as phytoplankton biomass, net primary production and CO2 air-sea flux. Then, chlorophyll, nutrients, oxygen, and carbonate system variables show also satisfactory uncertainty in reproducing in situ observations at the mesoscale and weekly temporal scale. The uncertainty increases for a few variables (i.e., oxygen and ammonium) in the mesopelagic layers. Finally, using specific and process-oriented skill metrics based on BGC-Argo data, the vertical dynamics of phytoplankton and nitrate are positively assessed.

As a consequence of the continuous increases in temperature, salinity and atmospheric CO2 in the Mediterranean Sea over the last 20 years, the reanalysis results indicate basin-wide biogeochemical signals of surface deoxygenation, increase in alkalinity and dissolved inorganic carbon concentrations, and decrease in pH at the surface. The new, high-resolution reanalysis, open and freely available from the Copernicus Marine Service, allows users from different communities to investigate the spatial and temporal variability in 12 biogeochemical variables and fluxes at different scales (from the mesoscale to the basin-wide scale and from daily to multiyear scales) and the interaction between physical and biogeochemical processes shaping Mediterranean marine ecosystem functioning.
A model for the secular magnetic field variation caused by Jupiter’s zonal winds
Authors: Wicht Johannes , Christensen Ulrich R.
Published: March 2022

The secular variation of the geomagnetic field is routinely used to infer the flow on the top of Earth’s liquid iron core. Recent gravity measurements by the Juno spacecraft suggest that the zonal winds observed on Jupiter’s surface reach about 3000 km deep. The observed variation in Jupiter’s magnetic field could provide additional constrains on the structure and speed of the zonal winds at depth. However, the interpretation of the secular variation is complicated by the fact that the electrical conductivity and thus magnetic effects increase rapidly with depth while the zonal winds decay with depth. Here we use a simple numerical model to explore the possible secular variation due to Jupiter’s zonal winds. We restrict the simulations to the outer 10% in radius and imposed the Jupiter-like magnetic field as a potential field. Different profiles for the depth dependence on electrical conductivity and winds are explore. The shear of the zonal winds increases the magnetic field dissipation over time. The dissipation seeks to balance induction and thereby reduces the secular variation. As the simulation progresses, the secular variation observed at the surface represents the zonal flow at increasing depth. The induced field also tends to significantly reduce the effective field strength at the surface. Out results suggest that the zonal flow action heavily shapes and weakens Jupiter’s magnetic field. However, the zonal flow induced secular variation would only reflect the slower flows at depth and may not contribute much to the total secular variation.
Fracture, mechanics and chemistry: Intermittency and avalanche statistics in thermally activated creeping crack fronts along disordered interfaces
Authors: Toussaint Renaud , Vincent-Dospital Tom , Cochard Alain , Santucci Stéphane , Måløy Knut Jørgen
Published: March 2022

We propose a subcritical fracture growth model, coupled with the elastic redistribution of the acting mechanical stress along rugous rupture fronts. We show the ability of this model to quantitatively reproduce the intermittent dynamics of cracks propagating along weak disordered interfaces [1]. We assume that the fracture energy of such interfaces (in the sense of a critical energy release rate) follows a spatially correlated normal distribution. We compare various statistical features from the obtained fracture dynamics to that from experimental cracks propagating in sintered polymethylmethacrylate (PMMA) interfaces. In previous works, it has been demonstrated that such approach could reproduce the mean advance of fractures and their local front velocity distribution. Here, we go further by showing that the proposed model also quantitatively accounts for the complex self-affine scaling morphology of crack fronts and their temporal evolution, for the spatial and temporal correlations of the local velocity fields and for the avalanches size distribution of the intermittent growth dynamics. We thus provide new evidence that Arrhenius-like subcritical growth laws are particularly suitable for the description of creeping cracks.

Reference:

[1] Vincent-Dospital, T., Cochard, A., Santucci, S., Måløy, K.J., Toussaint, R.,  Thermally activated intermittent dynamics of creeping crack fronts along disordered interfaces. Sci Rep 11, 20418 (2021). https://doi.org/10.1038/s41598-021-98556-x
The use of impact chains and Bayesian Network Analysis to assess flood risk dynamics in the Lower Mono River Basin, Benin
Authors: Wetzel Mario , Schudel Lorina , Almoradie Adrian , Komi Kossi , Adounkpe Julien , Walz Yvonne , Hagenlocher Michael
Published: March 2022

River floods are a common and often devastating environmental hazard causing severe damages, loss of lives and livelihoods, notably for the most vulnerable. Understanding the root causes, drivers, patterns and dynamics of flood risks and associated uncertainties is important to inform adequate risk management. Yet, a lack of understanding the highly dynamic processes, interactions, uncertainties, and the inclusion of participatory methods and transdisciplinary approaches in risk assessments remains a limiting factor. In many flood-prone regions of the world, data scarcity poses another serious challenge for risk assessments. Addressing the above, we developed an impact chain via desk study and expert consultation to reveal key drivers of flood risk for agricultural livelihoods in the Lower Mono River Basin of Benin and their interlinkages – a region that is both highly prone to flooding and can be considered data-scarce. Particularly, the dynamic formation of vulnerability and its interplay with hazard and exposure components is highlighted.

Based on a simplified version of the impact chain which was validated in a participatory manner during a virtual expert workshop, an alpha-level Bayesian Network was created to further explore these interactions. The model was applied to an exemplary what-if scenario for the study area in Benin. Based on the above, this study critically evaluates the benefits and limitations of integrating the two methodological approaches to better understand and simulate risk dynamics in data scarce environments. The study finds that impact chains are a useful approach to conceptualize interactions of risk drivers. Particularly in combination with a Bayesian Network approach the method enables an improved understanding of how different risk drivers interact within the system and allows for dynamic assessments of what-if scenarios, for example, to inform resilience building strategies.
High-resolution sea ice edge forecast around Greenland: response to the forcing and forecast evaluation
Authors: Ponsoni Leandro , Hvid Ribergaard Mads , Soya Rasmussen Till
Published: March 2022

The Danish Meteorological Institute (DMI) is the authority in charge of the sea ice service that supports mariners off the Greenlandic coast. DMI has offered ice charts and in-person consultancy for many years. Over time, the portfolio of sea ice products has extended to include forecast and automated retrievals and translations of remotely sensed data to sea ice products. Recently, DMI has launched an improved, high-resolution sea ice operational forecast system (SIOFS). The newly-launched DMI-SIOFS is updated with an improved model configuration with a nominal horizontal resolution of 5 km that predicts the ocean and sea ice states. The system is based on the coupling of the 3D ocean model Hybrid Coordinate Ocean Model (HYCOM; e.g., Chassignet et al. (2007)) with the Community Ice CodE model (CICE; e.g., Hunke and Dukowicz (1997); Hunke (2001)). Apart from the horizontal resolution, the sea ice component is improved with parameterization of features such as landfast sea ice and melt-ponds, as well as enhanced sea-ice salinity and thermodynamics schemes. The freshwater discharge from Greenland has also been upgraded by using inputs from the Geological Survey of Denmark and Greenland (GEUS; https://eng.geus.dk/) that improves the coastal ocean currents and, consequently, the sea ice transport nearshore Greenland. As a final product, a 144 hourly forecast of sea ice conditions is produced twice a day and released on Polarportal (http://polarportal.dk/en/home/).

With a focus on the waters surrounding Greenland, this study introduces the DMI-SIOFS and provides the first evaluation for it in terms of predicted sea ice edge location – an essential diagnostic for mariners. To do so, we make use of the Integrated Ice Edge Error (IIEE) metric introduced by Goessling et al. (2016). In addition, we provide insights on the model response to different forcing.

 
Radiative forcing and climate feedbacks explain the cause of the suppressed late 20th century warming in CMIP6 models
Authors: Smith Christopher , Forster Piers , Fredriksen Hege-Beate
Published: March 2022

For the 1960-2000 period, the latest generation of climate models (CMIP6) shows less global mean surface temperature change relative to pre-industrial than that seen in observations. In contrast, the previous generation of models (CMIP5) warmed in line with observations over this period. It has been hypothesised that this suppressed late-20th Century warming seen in CMIP6 is caused by a stronger aerosol effective radiative forcing (ERF) than in CMIP5. We investigate the role that historical ERF plays in historical global mean warming. 

To diagnose the historical ERF we determine the climate feedback parameter from regression of top-of-atmosphere energy imbalance against temperature in abrupt-4xCO2 runs and use the diagnosed climate feedback values in the historical simulations from the same models. We evaluate the historical ERF in 35 CMIP6 and 27 CMIP5 models. We show that this method to estimate ERF is a fairly good approximation to more accurate estimates using atmosphere-only integrations from the Radiative Forcing Model Intercomparison Project (RFMIP). The agreement with RFMIP is best in those models with little or no time dependence (curvature) in their climate feedback parameter. However, the historical ERF estimate can be improved by considering the non-linearity in climate feedbacks. To do this we repeat the process using a three time-constant regression model, showing that this method gives results that are much closer to RFMIP in those models that perform poorly with the one-parameter model.

Under both the one- and three-parameter methods, we show that total historical ERF is lower in CMIP6 than in CMIP5 for 1960-2000. This lower forcing at first appears to explain the differences in warming between the CMIP6 and CMIP5 ensembles. To dive deeper into the contribution to historical forcing we also estimate ERF contributions from greenhouse gases, other anthropogenic forcers (including aerosols), and natural forcing in the subset of CMIP6 and CMIP5 models that performed experiments from the Detection and Attribution Model Intercomparison Project (DAMIP). The causes are a stronger negative aerosol ERF and weaker positive greenhouse gas ERF in CMIP6 compared to CMIP5. However, these forcing differences are amplified by differences in climate sensitivity between the CMIP5 and CMIP6 ensemble, which leads to both a stronger aerosol cooling over 1960-1990 and a stronger greenhouse gas induced warming from 1990 in CMIP6.
Australian Black Summer smoke observed by lidar at the French Antarctic station Dumont d’Urville
Authors: Tencé Florent , Jumelet Julien
Published: March 2022

In the follow-up of the Australian”Black Summer” event that persisted from August 2019 to March 2020, we present the optical properties of the stratospheric aerosols injected into the atmosphere by these wildfires. The outbreak of pyrocumulonimbus(PyroCb) activity triggered between 2019/12/29 and 2020/01/04 have raised the stratospheric aerosol load of the Southern Hemisphere to unprecedented levels.  Long-range transport brought some of the plumes down to the Antarctic region, where general circulation patterns kept them circling around the continent.  The 532nm Rayleigh/Mie/Raman ground-based lidar of the French Antarctic station Dumont d’Urville (DDU,66.6°S – 140°E) acquired unprecedented time series of these carbonaceousaerosols starting approximately days after the injection and up to the most recent measurements in October 2019 where local radiosonde reported anomalous ozone depletion as compared to the decadal average.  The lidar provides a first and unique time series at high vertical and temporal resolution, complemented by satellite measurements from OMI, OMPS and MLS. Aerosol backscatter ratio decreases from 1.9 to 1.2 between January and June 2020.  Aerosol origin and persistence are characterized, as well as their optical properties and vertical distribution on several months.

In this presentation we will introduce the station and instrumental capabilities along with the latest measurements following the publication of Tencé et al., jgr, 2022.
Southern Tibetan rifting controlled by basal shear and heterogeneities of the underthrusting Indian lithosphere 
Authors: Bao Xuewei , Zhang Bingfeng , Xu Yixian , Yang Wencai
Published: March 2022

The dominant driving forces for the east-west extension of the Tibetan Plateau since the mid-late Miocene remain vigorously debated. Proposed hypotheses encounter difficulties in reconciling the geological observations of more developed north-trending rifts in southern Tibet as well as the discrepant extension magnitudes among them. With seismic recordings collected from our recently deployed and existing seismic arrays, we locate a mid-crustal simple shear zone characterized by convergence parallel anisotropy beneath the southern plateau, which is likely caused by the underthrusting of the Indian Plate. Furthermore, a zone of reduced S-wave velocity is also resolved between the two rifts with highest extension rate, indicative of the convective removal of the lower Indian mantle lithosphere. Taken together, our results suggest that the enhanced extension occurring in southern Tibet are controlled by both the shear tractions induced by the advancing Indian Plate and the increased buoyancy due to asthenospheric upwelling.
Year-round optical properties of atmospheric mineral dust particles at Dome C (East Antarctica): radiative and paleoclimatic implications
Authors: Potenza Marco , Delmonte Barbara , Del Guasta Massimo , Cremonesi Llorenç
Published: March 2022

We present preliminary results from the project OPTAIR, aimed to study the optical properties of airborne particles at Concordia Station, on the East Antarctic plateau, and to assess the relationship among the optical properties of particles suspended in air and deposited by the snow. Light scattering data from single particles are collected continuously by a permanent device installed in November 2018, operating the novel Single Particle Extinction and Scattering method and some traditional scattering measurements. Data are put in correlation with LIDAR measurements, with the aim to assess the impact on past and present climate. Results from the Antarctic season 2019 will be presented, showing clear evidence of remarkable changes in the amount of particles, size and optical properties across the year. In particular, about one third of the total cumulative dust particles accumulated in one year is advected during fast dust-rich air mass subsidence events lasting a few hours. This feature is of major importance to glaciological studies based on integrated, multi-annual snow and ice samples.
Migrating solar diurnal tidal variability during Northern and Southern Hemisphere Sudden Stratospheric Warmings
Authors: Siddiqui Tarique Adnan , Stolle Claudia , Yamazaki Yosuke
Published: March 2022

In this study, the variability of migrating solar diurnal (DW1) tide in the mesosphere-lower thermosphere (MLT) region during Northern and Southern Hemisphere (NH & SH) Sudden Stratospheric Warmings (SSWs) is investigated using Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature  observations and reanalysis-driven Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X) simulations. The periods examined include four major NH SSWs that occurred during January in 2006, 2009, 2010 and 2013 and two SH SSWs that were recorded in September in 2002 and 2019. Our analysis shows that the observed DW1 tide displays a marked decline in the equatorial region after the onset of NH and SH SSWs. As WACCM-X simulations qualitatively reproduce this feature of DW1 tidal variability common to both NH and SH SSWs, they have been used to examine the possible mechanism that could explain these observations in DW1 tide. It is known that changes in the latitudinal shear of zonal winds at low-latitudes strongly affect the seasonal variation of DW1 tide in the MLT. We explore this mechanism to show that SSW-associated changes in the latitudinal shear in the MLT could be used to explain the observed variability of DW1 tide during NH and SH SSWs.
AGRICA - Climate Risk Profiles for Sub-Saharan Africa
Authors: Gleixner Stephanie , Tomalka Julia , Lange Stefan , Gornott Christoph
Published: March 2022

Many countries recognise the importance of adaptation to climate change, but have limited access to reliable information on climate impacts and risks which should inform the selection of adaptation strategies. The AGRICA Climate Risk Profiles (CRPs) provide a condensed overview of present and future climate impacts and climate risks for different sectors. Based on projections from four climate models under two Greenhouse Gas emission scenarios, climate and climate impact data from the ISIMIP project is used to assess changes in climate, water resources, agriculture, infrastructure, ecosystems and human health. To date, CRPs have been published for 12 countries in sub-Saharan Africa and further CRPs are currently being developed both under the AGRICA project as well as in collaboration with external organisations. The CRPs are intended to inform decision makers from governments, international institutions, civil society, academia and the private sector regarding the risks of climate impacts in key sectors. The findings can feed into national and sub-national climate adaptation planning including NDC and NAP development, implementation and review, but also provide useful information and evidence at other strategic planning and implementation levels.
Virtual excursion in the "Rheinisches Schiefergebirge" between Rüdesheim and Lorch
Authors: Owin Julian
Published: March 2022

This paper deals with the creation of a virtual excursion in the Rheinisches Schiefergebirge between Rüdesheim and Lorch. The virtual excursion serves as a supplementary teaching method for students of geosciences. The challenges posed by the Corona pandemic also require a rethinking of how excursions are conducted. These are highly relevant in the field of geosciences, as the study programme is very practice-oriented and thus the theoretical basics can be applied practically. Furthermore, excursions involve not only spatial but also physical challenges. With the help of the digital excursion, the students have the opportunity to explore the area on their own, without the presence of the supervising lecturer, and to evaluate the information provided about the rock. In addition to an overview of the location and size of the rock, detailed representations of the structure of the rock are also available. In order to be able to present this depth of information in digital form, Google-KMZ files (https://seafile.rlp.net/d/f2e4fc83a52b4a749f2d/) and 3D models of the area to be explored were created using a digital camera, a GPS device and photogrammetry software. 

Even though the digital excursion offers a wealth of data about the rock to be explored, they are not intended to replace classical excursions, but rather to complement them. In addition, they offer meaningful support for the teaching of geosciences.
Comparing long short-term memory and convolutional neural networks in SYM-H index forecasting
Authors: Siciliano Federico , Consolini Giuseppe , Giannattasio Fabio
Published: March 2022

Geomagnetic indices can have a central role in the mitigation of ground effects due to space weather events, for instance when their reliable forecasting will be achieved. To this purpose, machine learning techniques represent a powerful tool. Here, we use two conceptually different neural networks to forecast the SYM-H index: the long short-term memory (LSTM) and the convolutional neural network (CNN). We build two models and train both of them using two different sets of input parameters including interplanetary magnetic field components and magnitude and differing for the presence or not of previous SYM-H values. Both models are trained, validated, and tested on a total of 42 geomagnetic storms among the most intense that occurred between 1998 and 2018. Results show that both models are able to well forecast SYM-H index 1 hour in advance. The main difference between the two stands in the better performance of the one based on LSTM when SYM-H index is included in the input parameters and, contrarily, in the better performance of the one based on CNN for predictions based only on interplanetary magnetic field data.
Quantifying active faulting using marine terraces, Kythira island, Greece
Authors: Jara-Muñoz Julius , Tsanakas Konstantinos , Karymbalis Efthymios , Yildirim Cengiz , Pedoja Kevin , Batzakis Dimitrios- Vasileios , Griva Diamantina
Published: March 2022

The coastal morphology of islands may furnish valuable information regarding deformation rates, their controlling mechanisms and the dynamics of the upper crust in offshore areas along subduction zones. Here we study active deformation and faulting at glacial-cycle time scales in the Kythira island, located at the western part of the Hellenic subduction zone, between Crete Island and the Peloponnese. The island exposes an outstanding sequence of more than twelve successive levels of marine terraces that depict the Pleistocene active uplift of the island. The marine terraces are offset by several NNW-SSE and NNE-SSW active faults. We use high-resolution topography combined with morphometric analysis to map the sequence of marine terraces and active faults. We divide the marine terrace sequence into two groups, the higher marine terraces (260 – 480 masl) include polygenic rasa surfaces, the lower terraces (20 – 220 masl) are characterized by staircase morphologies. Based on a proposed correlation with sea level curves, we estimated ages ranging between MIS 17 and MIS 22 (712 – 1000 ka) for the higher terraces and between MIS 5 and MIS 15 (125 – 620 ka) for the lower terraces. We focus on the two main faults of the island, defined as F1 and F2, they display right- and left-lateral and dip slip displacements, offsetting the marine terrace risers and treads and producing local drainage anomalies. Based on the proposed terrace ages we derived preliminary heave rates between 0.3 and 0.5 m/ka for the right-lateral fault F1 and between 0.8 and 1 m/ka for the left-lateral fault F2. Mean throw rates vary between 0.01 m/ka and 0.03 m/ka for F1 and F2 respectively. We link the activity of these faults with the occurrence of intermediate-depth and strong magnitude earthquakes such as the Mw 6.6 and 6.7 occurred in the area of Kythira in 1903 and 2006, respectively. Further dating of marine terrace deposits and surfaces, and structural analysis will be carried soon to refine our preliminary estimates. Our work emphasizes on the importance of studying islands to elucidate vertical and horizontal deformation rates in offshore areas of subduction zones.
Magnetosphere-Ionosphere Coupling and Aurora at Jupiter and Saturn
Authors: Bunce Emma
Published: March 2022

I will review the main magnetosphere-ionosphere (MI) coupling mechanisms thought to play a role at Jupiter and at Saturn. We are interested in the extent to which the magnetospheres are driven by internal processes (plasma sources, planetary rotation) versus external mechanisms (solar wind, interplanetary magnetic field). At both planets, momentum is mostly transferred via the rotating planetary magnetic field from the ionosphere to the magnetosphere. The solar wind can also play a role in driving dynamics, e.g. via the interaction of corotating interaction regions (CIRs). The NASA/ESA Cassini Huygens mission revealed that Saturn’s system also has a unique feature driven by the ionosphere known as “planetary period oscillations”. These phenomena interact with the effects of the solar wind to produce complex MI coupling signatures. The NASA Juno mission has provided the first in situ evidence of MI coupling in Jupiter's polar magnetosphere. I will compare the similarities and differences between observation and theory discovered thus far.