bluuebunny/crossref_metadata_2025 huggingface dataset:
Urban heat island under climate change. The case study of Milano, Italy.
Authors: Casale Francesca , Zhang Wenchuang , Bocchiola Daniele
Published: February 2023

Poli-HE, a coupled hydrological-energy budget model was developed to simulate the surface water, and energy fluxes between soil and shallow atmospheric boundary for the city of Milano, Northern Italy. So doing, we describe the urban heat island effect, i.e. differences in land surface temperature (LST) between paved/urban, and green/natural areas, i.e. parks, and suburban agricultural patches.Energy and water balance equations are linked through soil water content (W), and latent heat flux (LE), calculated as a function of the LST. W in turn drives (actual) evapotranspiration, thus driving (water) mass balance. Input variables were used from i) meteorological stations, air temperature (Ta), net radiation (Rn), rainfall (R), and ii) satellite images, giving leaf area index (LAI) and land surface temperature were used for model tuning.The results show large differences in LST between urban/green areas, high during summer, viz 3-4 °C, lower in winter, viz 0.3°C. During 2010-2021 max surface temperature in Milano was +37.3°C in urban areas, and to +33.6°C in the green areas.The model was then used for future projections of LST, using outputs of the Global Circulation Model EC-Earth3.0, constrained to shared socio-economic pathways SSP1-2.6 and SSP5-8.5 of the CMIP6. We analysed near (2030-2041), medium (2050-2061) and long-term (2080-2091). On average in the city of Milano, LST is projected between +0.14°C (SSP 2.6 in the medium-term), and +6.35°C (SSP 8.5 in the long-term). The jump of LST between urban/green areas would reduce against average increase of air temperature, and LST, i.e. large increase of air temperature will be less and less dampened by the present green area cover.
Resolving Hydro-Mechanical Earthquake Cycles with a GPU-based Accelerated Pseudo-Transient Solver
Authors: Wu You , Dal Zilio Luca , De Monserrat Albert , Team the Bedretto
Published: February 2023

Modeling earthquake source processes is a multi-physics and multi-scale endeavor that tightly links several disciplines, including seismology, numerical computing, continuum mechanics, materials science, and engineering. In particular, incorporating the full range of coupled mechanisms, including complex fault geometries, off-fault inelastic processes, realistic shear-layer response, and fluid effects, brings significant programming and computational challenges. Furthermore, the development of highly efficient, robust and scalable numerical algorithms lags behind the rapid increase in massive parallelism of modern hardware. To address this challenge, we present a physically motivated derivation of coupled solid-fluid interactions on faults using an innovative accelerated pseudo-transient (PT) iterative method. The general approach involves transforming a time-independent problem into an evolution problem, which allows us to utilize the benefits of the Method-of-Lines (MOL) approach with the accelerated PT method. Additionally, we provide an efficient numerical implementation of PT solvers on graphics processing units (GPUs) using the Julia programming language. Julia solves the “two-language problem”, where developers who write scientific software can achieve desired performance, without sacrificing productivity. As a result, this enables us to develop high-performance code for massively parallel hardware with modern GPU-accelerated supercomputers, without requiring architecture-specific code. We aim to unveil preliminary results on the application of PT solvers to fully compressible poro-visco-elasto-plastic media, wave-mediated fully dynamic effects, rate-and-state dependent friction, and an adaptive time stepping to resolve both long- and short-time scales, ranging from years to milliseconds during the dynamic propagation of dynamic rupture. Our work can contribute to a better understanding of the accelerated PT method and its potential for facilitating the implementation of various numerical models in the field of computational earthquake physics. 
A downscaling exercise for the Adriatic Sea in a perfect model approach
Authors: Tatsch Eidt Renata , Verri Giorgia , Santos da Costa Vladimir , Gunduz Murat , Navarra Antonio
Published: February 2023

In this study, the predictability of the coastal ocean is assessed in a downscaling exercise for the Adriatic Sea using NEMO 3.6 over a 19 years’ time window (2001-2019). Inspired by the perfect model approach (Denis et al. 2002, De Elia et al. 2002) using a dynamical downscaling setup, a high resolution (2 km) experiment (Big Brother – BB) for the entire Adriatic Sea is used as the “true” reference for a smaller domain, downscaling experiment (Little Brother – LB) in the Northern Adriatic subbasin. The LB experiment has the same horizontal resolution as the BB (2 km) and is downscaled from a low resolution parent model (6 km), in a ratio of 1/3 resolution jump. The 2 km horizontal resolution fits the purpose of reaching an eddy-permitting grid spacing in the Adriatic basin (Masina and Pinardi, 1994; Cushman-Roisin et al. 2002).Power spectral density analysis is used to evaluate the kinetic energy variance on the frequency domain among the experiments and compare them with the BB experiment. Overall, the LB is more energetic than the parent model, and the timing of the peaks of energy coincides with the ones of the BB. The energy on the 1 year signal is higher in the LB than the BB. The LB can recover a significant amount of energy for all peaks, with special attention to the 6 months period, which is poorly captured by the parent model. The 4 months signal is equally represented in BB and LB, while there is an underestimation of the 6 months signal of LB with respect to BB. Energy in the LB does not deviate from BB more than ~20% in the low frequencies and ~10% in the high frequencies, while the parent model presents in a whole lower energy than the BB, with higher differences on the low frequencies.The Northern Adriatic circulation is largely influenced by the surface buoyancy flux and the wind forcing (Cessi et al., 2014), which play a significant role in the energy budget and the anti-estuarine overturning circulation of the Adriatic basin. Differences between LB and parent model results may be associated with the energy cascade due to interactions of internal dynamic processes which are differently represented at different resolutions. Differences between LB and BB results are the effect of the downscaling method and the horizontal resolution ratio between the parent model and the nested LB.Moreover, the analysis of the wavenumber spectra allows a clear overview of the energy distribution in the space domain among the experiments and the representation of small-scale features in the LB. Small scale features less than twice the grid spacing (~12 km) are absent in the low-resolution parent model outputs. Therefore, the comparison with the true reference, BB, reveals the energy spectrum of the parent model solves only the larger scales, while the downscaling LB can recover the smaller scales absent in the initial and lateral boundary conditions.
Monitoring glacier fade out in Austrian Eastern Alps
Authors: Fischer Andrea , Stocker-Waldhuber Martin , Hartl Lea , Helfricht Kay , Gschwendtner Andreas , Seiser Bernd , Bertolotti Giulia
Published: February 2023

In the Austrian Alps, recent rapid glacier melt affected the glaciers up to the summits. Glacier disintegration, debris flows, rock falls and increased melt rates are challenging glacier monitoring. Apart from the technical and safety issues arising, the scientific question arises how long a glacier fade out can and should be observed.

From a technical perspective, direct mass balance monitoring is hampered by destruction of stakes by rock fall and snow pressure mounted on the increasingly steep glacier surfaces. Glacier changes require a frequent repositioning of stakes. Deep parts of the glaciers where stakes were not mounted in the past because the area was heavily crevassed remain longer that the thinner parts where stakes were operated in past decades, for example on Jamtalferner/Silvretta.

Area loss meanwhile has a significant impact on glacier wide specific mass balance, but an annual resurvey of glacier area by terrestrial photogrammetry, airborne LiDAR or UAV rises the monitoring costs and effort considerably, while the uncertainty of mapping glacier area from remote sensing images is hampered by resolution and/or debris cover.  

Subglacial melt in large cavities which developed during the last years so far is not quantified, but estimated from thickness loss data suggest that the contribution of basal mass loss to total mass loss can be as large as surface mass balance.

Common definitions of a glacier imply ice formation from snow and firn, ice dynamics and a runoff system. For several Austrian glaciers, snow and firn cover is entirely gone. There, no new ice can form during the next decades even in case accumulation of snow would take place in future. In addition to that, flow velocities drop to <5 m/year, which is a similar magnitude than that measured for rock glaciers. From a glaciological perspective, those (former?) glaciers rather meet the definition of dead ice, especially when covered by debris.

From a hydrological perspective, monitoring of those glacier remnants still makes sense, as they are still part of the local hydrological system. From the perspective of hazard monitoring, glacier remnants are also worth monitoring as they are relevant for generation of debris flows and englacial/thermokarst lakes.

To continue local glacier monitoring and contribute to a global database, a joint global monitoring strategy and methodology would be beneficial. For example, a definition of ‘transient glaciers’ in fade out with a specification of monitoring methods would be helpful to prolongate mass balance time series when direct measurements become impossible for the total area. That could be single stakes, geodetic methods when glacier margins are still clear, or hydrological methods.   
Downscaling climate change impacts on socio-economic parameters in a storyline-based investigation
Authors: Schachtschneider Reyko , Saynisch-Wagner Jan
Published: February 2023

Climate change has drastic impact on our lives and many socio-economic parameters. The exact consequences are hard to quantify and in general not obvious and not clear to the general public. In this work we use the storyline scenarios from within the SCENIC project for the prediction of various socio-economic parameters in warmer climates. We use machine learning algorithms to investigate how parameters that have direct impacts on society and the population develop in different warmer world scenarios. For this purpose we train echo state networks. Input data are temperature and humidity fields over Europe. Output data are time series of, e.g., mortality rates, forest fires, crop yield, and consumer price indices from Germany. The output data are predicted under the investigated climate scenarios of +2K and +4K with respect to pre-industrial time.
Unexpected local magnetic depression around Mercury: BepiColombo flyby-2 discovery
Authors: Schmid Daniel , Fischer David , Magnes Werner , Narita Yasuhito , Volwerk Martin , Baumjohann Wolfgang , Matsuoka Ayako , Auster Hans-Ulrich , Richter Ingo , Heyner Daniel , Plaschke Ferdinand , Nakamura Rumi
Published: February 2023

BepiColombo MPO and Mio spacecraft encounter the Mercury magnetosphere six times from 2021 to 2025 during the flyby maneuvers. Each flyby trajectory is unique and includes the magnetospheric regions that were not covered by MESSENGER. Mio/MGF magnetic field data were successfully retrieved during the Mercury flyby-2 in June 2022 and the data were calibrated for the scientific use. The MGF measurements show a short-time intense magnetic field depression in close proximity to the planet at local midnight, which is neither expected from the earlier observations (Mariner-10, MESSENGER) nor from the hybrid plasma simulations of the Mercury magnetosphere. Both time-dependent and time-independent scenarios are possible, including the occurrence of a transient event driven by sudden changes in the solar wind (e.g., pressure puls) or in the magnetosphere (e.g., magnetic reconnection) and the crossing of a localized current layer separating the dipolar field region from the stretched tail-like magnetic field region. While more dedicated analyses (wave analysis, variation analysis), combination with the other data (plasmas and imaging), and numerical simulations for different scenarios would improve the quality of scientific interpretation of the depression event, our study demonstrates the scientific potential of BepiColombo that it will detect various kinds of transient events and localized structures in Mercury’s magnetosphere already during the flyby maneuvers.
Investigation of olivine's thermostability in an oxidized and reduced atmosphere
Authors: Brau Joanna , Schmitt-Kopplin Philippe , Kaliwoda Melanie , Scheu Bettina , Dingwell Donald B
Published: February 2023

Olivine is an abundant phase of ultramafic and mafic rocks in the earth's crust and mantle. Stony meteorites or stony-iron meteorites like pallasites also contain a lot of extraterrestrial olivines. During atmosphere entry olivine-containing meteorites experience different oxygen levels and intense heating for brief intervals, creating fusion crusts that are a few millimetres thick. As a result, various thermal pathways between the rim and the core are anticipated for meteoritic olivines. This shows different colours in natural pallasitic olivines. We are particularly interested in the effects of environmental variables on both terrestrial and interplanetary olivines, based on terrestrial olivines. Natural volcanic olivines from the 1959 Kilauea eruption in Hawaii, the Aheim mine, Norway, are employed and a stony-iron pallasite (collected 1822 – Atacama Desert). We generate two environments using a gas-tight tube furnace that produces CO-CO2 gas mixes—one in air and the second with a reduced atmosphere (fO210-12 bar). The temperatures range from 950 to 1350 degrees Celsius (i.e. within the olivine stability field). After hand-picking single grains of olivines and putting them in Pt-Rh crucibles for an hour, the samples are lifted vertically out of the tube furnace and quenched in air. EPMA, SEM, RAMAN, and optical and laser microscopy are used to characterise and analyse the samples.Preliminary findings, olivines show thermal stability and have a homogeneous chemical composition both before and after heating. A reduced environmental exposure causes a change in colour, similar to the stony-iron pallasite which will be discussed. In association with those observations, we also see Raman bands nearby 600 cm-1 vanish, and Raman bands show up at 800 cm-1. We will compare these effects in relation to the findings from tests involving air exposure and compare the observations obtained from naturally occurring pallasitic olivines.
Remote Sensing Monitoring of Flood hazard in Arid Environments. A Case Study of Saquia El Hamra Watershed Morocco
Authors: El-alaouy Nafia , Moumni Aicha , Laftouhi Nour-Eddine , Lahrouni Abderrahman
Published: February 2023

Floods are the most visible and destructive hydrologic phenomenon in terms of human and economic loss. Typically, flash floods are caused by large amounts of runoff due to short duration and high-intensity rainfall. Floods also lead to environmental and social problems, such as damage to roads, farms, and infrastructures and sometimes pollute surface water resources via the transfer of industrial waste, creating many health problems. In late October 2016, a flash flood severely damaged the surroundings of the city of Laayoune in the Saquia El Hamra basin in southern Morocco. The country’s climate is arid and semi-arid and is prone to destructive floods. The purpose of this study is to evaluate this flash flood and monitor wetland areas after this event using a technique that relies on remote sensing technology. This work was accomplished using Sentinel 2 satellite images, from the European Space Agency, based on classification methods and change detection techniques. Before and after the occurrence, the SVM classifier was employed to map land cover and land use. The overall accuracy (Kappa coefficient) was 94.41 % (0.91), and 87.33 % (0.81), respectively for both dates, when compared to the ground-truth data. The decision tree was built with the maps produced by the SVM classification for both dates as inputs, producing a change detection map with increased detail. The remote sensing technology has enabled us to monitor the damage that has been done to the area following the catastrophe with details on the buildings affected, farms flooded, and the extent of the river.
Jets downstream of the Earth’s bow shock
Authors: Hietala Heli
Published: February 2023

The downstream region of a collisionless quasi-parallel shock is structured containing localized bulk flows with high kinetic energy density and dynamic pressure. In 2009, we presented Cluster multi-spacecraft measurements of this type of supermagnetosonic jet as well as of a weak secondary shock within the sheath. These observations allowed us to propose the following generation mechanism for the jets: The local curvature variations inherent to quasi-parallel shocks can create fast, slightly deflected jets accompanied by density variations in the downstream region. If the speed of the jet is super(magneto)sonic in the reference frame of the surrounding flow and/or the magnetopause, a second shock front forms in the sheath.During the following years, magnetosheath jets have been a continually active research topic. Studies using increasingly large databases of spacecraft observations have gathered the statistics of jet formation conditions and properties. Simulations and case studies have shed light on jet formation mechanisms. Within the magnetosheath, the jet-driven secondary bow waves/shocks have been shown to contribute to particle energization. Investigations of jet impacts on the magnetosphere have revealed a plethora of effects, ranging from surface waves and magnetopause reconnection to diffuse auroral brightenings.In this talk, we will summarize the progress to date and highlight some still open questions.
Climate-driven Hg-remobilisation triggering long-term disturbance in vegetation following the end-Triassic mass-extinction
Authors: Bos Remco , Zheng Wang , Lindström Sofie , Sanei Hamed , Waajen Irene , Fendley Isabel , Mather Tamsin , Sluijs Appy , van de Schootbrugge Bas
Published: February 2023

The Central Atlantic Magmatic Province (CAMP) eruptions are generally regarded as the main driver of major environmental change and mass-extinction across the Triassic-Jurassic (T-J) boundary (~201.3 Ma). CAMP emissions have been invoked as the main trigger for the formation of abnormal pollen and spores during the end-Triassic crisis that may have led to forest dieback and proliferation of pioneer species. Proposed scenarios include extensive climate change leading to wildfire activity, acid rain, and increased UV-B radiation due to ozone depletion. More recently, volcanogenic mercury (Hg) has been implicated in the occurrence of mutations in fern spores. However, Hg-dynamics in deep-time remain poorly understood and require further examination. Here, we explore a new long-term (Rhaetian to Sinemurian) bulk Hg-concentration record combined with Hg-isotope data to understand the link between floral turnovers and the Hg-cycle.Shallow marine sediments sampled from the Schandelah-1 core in northern Germany contain a record of cyclical shifts in malformed fern spores coinciding with fluctuations in carbon isotopes, increased levels of weathering, and Hg-enrichments. Similarly, increased mutagenic spore abundances with accompanying Hg-isotope records confirm the volcanogenic origin of Hg at the T-J boundary, showing a sharp positive excursion in mass-independent fractionation (MIF) of odd-numbered Hg-isotopes. Hettangian cyclicity is clearly reflected in the Hg-isotopic signals, showing positive excursions in mass-dependent/independent fractionation records (d202Hg and D199Hg) during periods of sedimentary Hg-enrichment. In addition, the Hettangian Hg-isotopic signature clearly deviates from Rhaetian signatures, which hints at climate-controlled mechanisms being responsible. Atmospheric Hg-loading via volcanism can explain the synchronous enrichments of Hg concentrations at the T-J boundary interval in multiple sites across the globe. In contrast, the origin of this periodic Hg-loading is more difficult to pinpoint, but it becomes clear that Hg is showing shifts in speciation and closely tied to terrestrial vegetation development. Orbitally induced changes to the regional hydrological regime, resulting in increased wildfire activity, monsoonal intensity, and soil erosion, potentially redistributed Hg stored in soil and/or bedrock reservoirs causing a shift to more mobile Hg-species. Overall, this shows a more dominant role of climate-induced Hg-remobilisation, rather than direct volcanic emissions, to disturbance in terrestrial vegetation.
Monitoring sediment processes in different delta systems in Swiss peri-alpine lakes through 4D bathymetric mapping
Authors: Kremer Katrina , Fabbri Stefano C. , Vendettuoli Daniela , Affentranger Carlo , Girardclos Stéphanie , Anselmetti Flavio S.
Published: February 2023

Deltas represent transfer zones where sediment is moved from terrestrial to the subaquatic domains. They are depositional areas and a source for sediments simultaneously. One of the aspects in this highly dynamic environment that has experienced so far little attention are slope failures in deltas. Such failures are, however, mentioned as potential cause for large (up to m-scale), graded deposits in the sedimentary record, often referred to as megaturbidites or homogenites. In some cases, they may have generated tsunamis in the near-shore area. These delta failures can be triggered, amongst other causes, by spontaneous slope collapses (e.g. Muota delta 1687 in Lake Lucerne, Switzerland). To better understand the controlling factors of slope stability in deltas, we need to comprehend the interplay between deltaic deposition and erosion through time and monitor their evolution.Repeated bathymetric mapping has been used as powerful tool to better understand the short-term processes occurring in deltas. In this contribution, repeated bathymetric mapping is used to better characterize, which short-term processes may shape subaqueous delta fronts. Using the dataset acquired in recent years in Swiss lakes, we seek to answer (1) what processes can be visualized based on repeated bathymetric mapping?; (2) which areas are prone to depositional/erosion processes?; and (3) what type of delta is more prone to slope failures? We present the first datasets of differential maps from four deltas in Switzerland that show different processes of erosion and deposition on short and long time scales. In addition, we will present the design of a planned multi-method monitoring campaign for delta processes in a sublacustrine delta in a peri-alpine lake in Switzerland. 
Measurement methods for ammonia emissions after field application of slurry
Authors: Kamp Jesper Nørlem , Pedersen Johanna , Huijsmans Jan , Götze Hannah , Pacholski Andreas , Hafner Sasha
Published: February 2023

Agricultural sources of atmospheric ammonia after slurry application vary over space and time, which makes it difficult to accurately quantify emissions. Different methods for concentration and emission estimation have been used by different institutions for many years, and these differences may contribute to variability in measurements. There is an need for commonly acceptable and reliable measurement methods.Ammonia emission measurements show a strong connection to the group that conducted them, suggesting effects of local soil properties, application techniques, or measurement method biases. The aim of this work was to clarify one source of these institutional effects related to applied measurement methods. Emission measurements with several common measurement methods were compared by three different research institutions simultaneously in the same field plots. This approach eliminates any variation from soil properties and application technique, making it possible to obtain new insight into the effect of measurement technique on model ammonia flux estimates.Two joint experiments were conducted at Research Center Foulum, Aarhus University (AU), Denmark, and one at Wageningen University and Research (WUR), the Netherlands. The four measurement methods included in the first experiment in Denmark were the backwards Lagrangian model (bLS) with online concentration measurement and wind tunnel measurements conducted by a AU group, while a group from Thünen Institute for Climate-Smart Agriculture conducted measurements with the Dräger Tube Method (DTM) and ALPHA passive diffusion samplers combined with bLS. The second experiment in the Netherlands included the integrated horizontal flux (IHF) method conducted by a WUR group using impingers as ammonia traps, while AU conducted bLS and wind tunnel measurements again. Furthermore, emission from both experiments were also estimated with the ALFAM2 model (v2.10, https://github.com/sashahafner/ALFAM2) based on the specific slurry and climatic parameters after slurry application.The difference in season and application method between the two experiments caused large differences in emissions as expected. The low time resolution measurements methods (DTM, ALPHA samplers with bLS, and IHF) tended to have lower emissions compared to the online and high time resolution methods (bLS and WT). More comparative measurements are needed to allow for more complete assessment of different methods.
Spatial Early Warning Signals for Rapidly Forced Systems
Authors: Clarke Joe , Cox Peter , Ritchie Paul , Huntingford Chris
Published: February 2023

Climate Change is forcing Earth System tipping elements rapidly, in some cases this forcing occurs on a similar timescale to the intrinsic timescale of the tipping element itself. This poses challenges for our ability to get good early warning signals for these tipping elements, as typical approaches require a clear timescale separation between the assumed slow forcing and the timescale of the system. We demonstrate that by calculating early warning signals ‘over space’ instead of ‘over time’ better early warning signals can be obtained for faster forcing. We compare the relative merits of these two ways of calculating early warning signals.
How does global warming affect European SOC stocks? A data-driven space-for-time approach
Authors: Schneider Florian
Published: February 2023

Global warming effects on soil organic carbon (SOC) stocks are expected to be site specific but current process-based models still struggle to forecast spatially explicit long-term trends properly. This study estimated such long-term effects of global warming on European SOC stocks using a novel data-driven space-for-time approach. In principle, this approach estimated site-specific SOC stocks under future climate from SOC stocks in comparable soils but in regions that are already exposed to such climate today. About 20k observations of the LUCAS soil dataset were used to train a machine learning model that predicted SOC stocks from current climate as well as static environmental properties (e.g. geology, soil type, soil texture). Then, this SOC model was used to forecast future SOC stocks in Europe under various CMIP6 climate scenarios. Preliminary results suggest Europe’s top 20 cm of mineral soil to loose on average 2 to 6 Mg SOC ha-1 by the end of this century. But global warming-induced changes in SOC showed pronounced regional differences. SOC was anticipated to even rise under global warming in some areas, particularly in Northern European forest ecosystems. In vast parts of southern Europe, unprecedented future climate limited the applicability of the data-driven SOC model. This was the case for up to 49% of all sites in the most extreme climate scenario. In contrast, for the remaining 51% of sites in all climatic scenarios, equivalent "soil-climate twins" could be successfully located elsewhere in contemporary Europe. It is proposed that outcomes from data-driven space-for-time models could complement and act as cross-checks for process-based modelling outputs to gain confidence in long-term projections of SOC stocks under global warming.
The Added Value of Remote Sensing Data in Downscaling Regional Climate Models
Authors: de Roda Husman Sophie , Hu Zhongyang , Kuipers Munneke Peter , van Tiggelen Maurice , Lhermitte Stef , Wouters Bert
Published: February 2023

Small-scale, subgrid processes on the ice sheets, such as localized surface melt, remain unnoticed by current coarse-resolution Regional Climate Models (RCMs), leading to uncertainties in climate reanalyses and projections. Deep learning allows us to enhance the spatial resolution of RCMs but requires sophisticated model development. Earlier studies have shown that rudimental techniques, such as single-image super-resolution, have failed to capture Antarctic surface melt patterns accurately, because the spatial transferability of these models is low. In this study, we add remote sensing data to a super-resolution model: daily observations of surface albedo from MODIS are used to guide the downscaling of low-resolution surface melt (RACMO2, 27 km) to a high-resolution version (RACMO2, 5.5 km) for a 20-year period, between 2001-2019. We extend a conventional SRResNet and add the MODIS data in different configurations (i.e., spatial-channel communication, content communication, and empirical-physical activation). The models are trained over the Antarctic Peninsula, for which RACMO2 simulations are available at 5.5 km resolution (Van Wessem et al., 2016). We verify the performance of the models with three independent datasets to inspect (1) the overall performance (using QuickSCAT); (2) spatial patterns (using Sentinel-1); and (3) temporal patterns (using automatic weather stations). Our work shows the potential of adding remote sensing data to deep learning-based downscaling models, leading to improved spatial transferability compared to single-image downscaling models.
Global societal vulnerability to volcanic eruptions
Authors: Mani Lara , Cassidy Mike , Tzachor Asaf , Cole Paul
Published: February 2023

The climatic cooling effects associated with large magnitude volcanic eruptions – the so-called ‘volcanic winter’ scenario – have long been identified as an extreme risk that may impact the continued flourishing of humanity. Such eruptions are relatively rare, but perhaps not as rare as we might think. A greater understanding of this mechanism and increased resolution of our geological records through the study of ice core records demonstrate that the recurrence of an eruption capable of this impact may be as frequent as 1 in 6 per century. These large magnitude volcanic eruptions (VEI 7 and above), could cause a global cooling event for up to a decade, if not longer, with more severe effects felt in the northern hemisphere, presenting a unique challenge for global food security.Further, viewed through the lens of vulnerability, human society now closely intersects with regions of volcanic activity, potentially forging new pathways for volcanic eruptions to cause global disruption. Our research identified regions of intersection, or ‘pinch points’, where a compounding of global critical systems and infrastructure, such as submarine cables, global shipping lanes, and transportation networks, are proximal to regions of volcanic activity. These pinch points present locations in our interconnected world where volcanic eruptions may disrupt our systems, cascading us toward global catastrophe. With climate change increasing the frequency and intensity of volcanic eruptions globally and enhancing their impacts, more must be done to accelerate our preparedness for such events.
Statistical inference methods and stable isotopes as a tool for predicting the quality of marine bathing waters
Authors: Mance Davor , Mance Diana
Published: February 2023

The movement of water as a scarce resource through the soil is a physical, causal-mechanical process characterized by the ability to continuously transfer a marker in space and time. A process is capable of transferring a marker if the marker, once introduced at a particular location, persists at other locations without further interaction. In this sense, stable isotopes are markers that are transferred from one location to another over time. The analysis of multiple indicators across space and time is known in statistics as longitudinal data analysis or panel data analysis. We show how some of these relatively new inductive statistical inference methods, in conjunction with known deductive nomological models, can be useful in building a predictive model for the quality of marine bathing waters in the Kvarner Bay (Adriatic Sea, Croatia).This work was supported by the University of Rijeka under the project numbers: uniri-pr-prirod-19-24, UNIRI CLASS – A1-21-8 34.
Estimating vegetation carbon stock components by linking ground databases with Earth observations
Authors: Kinalczyk Daniel , Wessollek Christine , Forkel Matthias
Published: February 2023

Land ecosystems dampen the increase of atmospheric CO2 by storing carbon in soils and vegetation. In order to estimate how long carbon stays in land ecosystems, a detailed knowledge about the distribution of carbon in different vegetation components is needed. Current Earth observation products provide estimates about total above-ground biomass but do not further separate between carbon stored in trees, understory vegetation, shrubs, grass, litter or woody debris. Here we present an approach in which we link several Earth observation products with a ground-based database to estimate biomass in various vegetation components. Therefore, we use information about the statistical distribution of biomass components provided by the North American Wildland Fuels Database (NAWFD), which are however not available as geocoded data. We use ESA CCI AGB version 3 data from 2010 as a proxy in order to link the NAWFD data to the spatial information from Earth observation products. The biomass and corresponding uncertainty from the ESA CCI AGB and a map of vegetation types are used to select the likely distribution of vegetation biomass components from the set of in-situ measurements of tree biomass. We then apply Isolation Forest outlier detection and bootstrapping for a robust comparison of both datasets and for uncertainty estimation. We use Random Forest and Gaussian Process regression to predict the biomass of trees, shrubs, snags, herbaceous vegetation, coarse and fine woody debris, duff and litter from ESA CCI AGB and land cover, GEDI canopy height, Sentinel-3 LAI and bioclimatic data. The regression models reach high predictive power and allow to also extrapolate to other regions. Our derived estimates of vegetation carbon stock components provide a more detailed view on the land carbon storage and contribute to an improved estimate of potential carbon emissions from respiration, disturbances and fires.
Use of Neural Networks for Tsunami Maximum Height and Arrival Time Predictions
Authors: Rodríguez Gálvez Juan Francisco , Macías Sáncez Jorge , Castro Díaz Manuel Jesús , de la Asunción Marc , Sánchez-Linares Carlos
Published: February 2023

Operational Tsunami Early Warning Systems (TEWS) are crucial for mitigation and highly reducing the impact of tsunamis on coastal communities worldwide. In the North-East Atlantic, the Mediterranean, and connected Seas (NEAM) region, these systems have historically utilized Decision Matrices for this purpose. The very short time between tsunami generation and landfall in this region makes it extremely challenging to use real-time simulations to produce more precise alert levels and the only way to include a computational component in the alert was to use precomputed databases. Nevertheless, in recent years, computing times for a single scenario have been progressively reduced to a few minutes or even seconds depending on the computational resources available. In particular, the EDANYA group at the University of Málaga, Spain, has focused on this topic and developed the GPU code Tsunami-HySEA for Faster Than Real Time (FTRT) tsunami simulations. This code has been implemented and tested in TEWS of several countries (such as Spain, Italy, and Chile) and has undergone extensive testing, verification and validation.In this study, we propose the use of neural networks (NN) to predict the maximum height and arrival time of tsunamis in the context of TEWS. The advantage of this approach is that the inference time required is negligible (less than one second) and that this can be done in a simple laptop. This allows to consider uncertain input information in the data and still providing the results in some seconds. As tsunamis are rare events, numerical simulations using the Tsunami-HySEA are used to train the NN model. This part of the workflow requires producing a large amount of simulations and large HPC computational resources must be used.Machine learning (ML) techniques have gained widespread adoption and are being applied in all areas of research, including tsunami modeling. In this work, we employ Multi-Layer Perceptron (MLP) neural networks to forecast the maximum height and arrival time of tsunamis at specific locations along the Chipiona-Cádiz coast in Southwestern Spain. In the present work, initially several individual models are trained and we show that they provide accurate results. Then ensemble techniques, which combine multiple single models in order to reduce variance, are explored. The ensemble models often produce improved predictions.The proposed methodology is tested for tsunamis generated by earthquakes on the Horseshoe fault. The goal is to develop a neural network (NN) model for predicting the maximum height and arrival time of such tsunamis at multiple coastal locations simultaneously. The results of our analysis show that deep learning is a promising approach for this task. The proposed NN models produce errors of less than 6 cm for the maximum wave height and less then 212 s for the arrival time for tsunamis generated on the Horseshoe fault in the Northeastern Atlantic.
The North Anatolian Fault: an example to regularity of ‘irregular’ seismic behaviour of continental strike-slip faults
Authors: Zabcı Cengiz , Altunel Erhan , Akyüz H. Serdar
Published: February 2023

In the complex puzzling of the lithospheric plates, the transform boundaries and related strike-slip faults are under focus of earth scientists for more than a hundred years not only for their important role in the lithospheric-scale deformation, but also for being sources of destructive earthquakes. Particularly, spatial and temporal seismic behaviour of these faults has been a subject of great curiosity for several decades with a special emphasis on the relationship between their geometry and earthquake recurrence. The North Anatolian Shear Zone (NASZ) is one of these tectonic structures, which makes the northern boundary of the Anatolian Scholle connecting the Hellenic Subduction in the west and the Arabia-Eurasia Collision in the east. This dextral system has a remarkable seismic history, especially in the 20th century, when the westward migrating earthquake sequence generated surface ruptures of about 1100 km with addition of ~140 km from two out of sequence events, 1912 Mürefte and 1949 Elmalı earthquakes, leaving unbroken only Marmara in the west and Yedisu in the east along its most prominent structure, the North Anatolian Fault (NAF).In this study, we aim to review palaeoseismic studies of more than three decades that provide invaluable information on the earthquake history all along the NAF with an attempt to understand which fault pieces have been involved in any of these palaeoevents. Thus, we decided to use their geometric properties, with an assumption that certain geometric discontinuities play an important role as end-points of an earthquake rupture. Palaeoseismological studies are grouped together according to the NAF’s geometric segments, on which they are located. In this classification, we excluded the ones with incomplete dating records or providing indirect evidence (i.e., cores). Then, we used a Bayesian approach to calculate the probability distributions of each palaeoevent, but applied it not to the individual sites but to the tectonostratigraphic data of merged trenches along the same fault segments. Our analyses suggest an ‘irregular’ seismic behaviour of the NAF although there are still gaps in data especially for the central parts. Large geometric complexities (e.g., Niksar step-over, Çınarcık Basin) significantly control the heterogenous stress conditions, but the ‘irregular’ behaviour is not only restricted to the segments close to these structures, but observed almost along the entire fault. In spite of the compiled 118 trench sites with more than 275 trenches, there is still necessity of further studies in order to increase the spatial and temporal resolution of palaeoseismic data along the NAF, especially for its central segments.
Increasing aridity reduces carbon sequestration in drylands by markedly lowering production but maintaining high rates of decomposition
Authors: Bigio Laura , Navon Yael , Konsens Irit , Lebrija-Trejos Edwin , Kigel Jaime , Sternberg Marcelo , M. Grünzweig José
Published: February 2023

Ecosystems in many regions worldwide are projected to experience increasingly dry conditions caused by warming, often associated with lower rain amounts. These trends are expected to result in a reduction in carbon stocks, as carbon sequestration declines with increasing aridity. However, it is unclear how some of the main processes controlling carbon sequestration add up to the decrease in carbon sequestration. Here, we investigated aboveground net primary production (ANPP) and litter decomposition in ephemeral herbaceous Mediterranean plant communities as affected by various degrees of aridity. The experimental design included four sites along a steep aridity gradient between dry-subhumid and hyperarid regions, and rainfall manipulations of -30% and +30% of ambient rain amounts.Results showed a progressively steeper decline in the carbon-related fluxes with increasing aridity. However, this decline was more pronounced for ANPP than for decomposition, a result supported by lower values for plant growth traits and higher values for litter decay traits at the drier compared with the wetter sites. Litter decomposition rate was more affected by litter quality and than by climate, as supported by a long-term transplantation study. Furthermore, litter quality increased with aridity and consequently litter from the most arid site decomposed faster than litter from the other sites.The combined outcome of reduced carbon input by less production and relatively quick decay of newly acquired biomass carbon was reflected by a steep decline in soil organic carbon (SOC) stock over most of the precipitation gradient. However, SOC at the most arid site was higher than expected from the combination of production and decomposition, potentially indicating efficient soil organic matter formation and stabilization.
Drone and field-based monitoring of the degassing and alteration structures of the La Fossa fumarole field (Vulcano Island), before and during the 2021 volcanic crisis
Authors: Müller Daniel , Walter Thomas R. , Troll Valentin , Stammeier Jessica A. , Karlsson Andreas , De Paolo Erica , Pisciotta Antonino Fabio
Published: February 2023

Fumarole fields and hydrothermal alteration are prominent signs of volcanic degassing at many volcanoes, and their monitoring is an essential part of the assessment of volcanic unrest. Yet, our knowledge about the detailed structure of fumarole fields and the spatiotemporal processes in their complexity is still poor, owing to limited accessibility. By using modern drone and sensor technologies we now are able to provide high-resolution data that allows us to analyze fumarole fields at cm-scales. From 2018 to 2022, we conducted repeated drone surveys at the fumaroles of La Fossa volcano on Vulcano Island (Italy). Drones equipped with a 20 MP camera and a radiometric thermal infrared sensor allowed the close-range acquisition of optical and thermal infrared images. By means of Structure from Motion (SfM) processing, the generation of high-resolution ortho- and infrared mosaic data was achieved. Applying Principal Component Analysis and image classification to the orthomosaic data, we detected and classified areas affected by degassing and hydrothermal alteration covering more than 60.000 sqm. By analyzing their spectral characteristics, we defined 4 surface types, of which type 1 and 2 are largely coincident with the thermally active surface. Type 3 is an altered low-temperature surface and type 4 is an unaltered surface. To evaluate these surface types, samples were analyzed in the lab for their mineralogical and geochemical composition by X-ray diffraction and fluorescence analysis, showing significant variability in composition. Further, we analyzed the spatial variability of the surface degassing activity using a portable multi-gas device. The combination of these methods allows us to constrain factors that are controlling the observed surface pattern of the degassing system, and to better understand the structural setup of the fumarole field and broader field of activity. We find that the actual high-temperature fumarole sites only account for <10% of the active surface. Besides, large thermally active areas, thermal aureoles for instance, display a rather diffuse activity. During the 2021 volcanic crisis, next to the high-temperature fumaroles, especially those diffuse features showed a response to the increased gas flux, emphasizing their structural importance. We summarize spatiotemporal variations during the crisis, and indicate possible widespread effects of the long-term gas-rock interaction like surface sealing, and forced lateral gas migration, affecting large parts of the fumarole field. The results suggest that detailed structural studies of fumarole fields by means of drone-based remote sensing in combination with in-situ measurements can contribute to a better understanding of degassing and alteration effects, with relevance for degassing sites elsewhere and during volcanic crises. 
Sulphur isotopes in Permian–Triassic evaporites: an 80‐million‐year record of pyrite burial
Authors: Salisbury Jack , Gröcke Darren , Cheung H.D.R. Ashleigh , Kump Lee , McKie Tom , Ruffell Alastair
Published: February 2023

The Permian–Triassic time interval is associated with major perturbations in the biogeochemical cycling of several redox-sensitive elements. In particular, sulphur isotope ratios (δ34S) reveal substantial perturbations in sedimentary sulphates. Despite this, few studies utilise this δ34S variability for long-term high-resolution correlation. Through the sulphur isotope analysis of sedimentary evaporites of the Staithes S-20 borehole (northeast England), we have generated the most stratigraphically complete evaporite sulphur isotope (δ34Sevap) curve from a single stratigraphic section for the late Permian to Late Triassic. The Staithes S-20 record and its comparison with the global δ34Sevap curve demonstrate the utility of sulphur isotope data for stratigraphic correlation and dating, especially evaporite bearing sequences. The δ34Sevap data for the late Permian to Late Triassic were incorporated into a biogeochemical box model to yield estimates for the pyrite burial flux with time. We propose three significant pyrite burial events (i.e. PBEs) throughout the Triassic. Our model outputs predict a major increase in pyrite burial over the Permian/Triassic boundary, possibly driven by Siberian Traps volcanism. After ~10 million years, the pyrite burial flux achieves relative stability until the latest Triassic.  