bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterising volatile organic compound emission changes in native black poplar under elevated carbon-dioxide (CO2), elevated ozone (O3) and herbivory
Authors: James Laura , Pfrang Christian , Girling Robbie , Hayward Scott , MacKenzie Rob
Published: March 2022

Plants communicate information about their status, intra- and inter- plant, and with other ecosystem members, through the release of volatile organic compounds (VOCs). The effects of rising CO2 in conjunction with ozone (O3) on plant VOC emissions is not yet fully understood, but research suggests that some herbivore-induced VOCs are degraded by O3, potentially reducing their signalling function. Furthermore, elevated CO2 has been shown to attenuate induced VOC responses to herbivory in Brassica oleracea. 

We are using two tri-trophic model systems; black poplar [Populus nigra betulifolia], winter moth [Operophtera brumata] and a tachinid fly parasitoid of winter moth, Cyzenis albicans; and oil seed rape [Brassica napus], diamond back moth [Plutella xylostella] (DBM), and a parasitoid of DBM, braconid wasp, Cotesia plutella. Additionally, we are working within two ground-breaking facilities; the Birmingham Institute of Forest Research (BIFoR)’s free-air carbon enrichment (FACE) experiment, and University of Reading’s free-air diesel and ozone enrichment experiment. We will also collect some data from lab-based experiments.

Our project seeks to characterise the volatile organic compound (VOC) profiles emitted for both plants under herbivory, examine how these VOC profiles differ under combined elevated CO2 and O3, and explore whether changes to VOC profiles impact key ecological relationships, e.g, the ability of plants to signal to herbivore enemies.
Morphodynamic response of tidal sand waves to sand extraction in the Belgian North Sea
Authors: Krabbendam Janneke , Nnafie Abdel , Roche Marc , Degrendele Koen , van Lancker Vera , de Swart Huib
Published: March 2022

Tidal sand waves are rhythmic bed forms with wavelengths of several hundreds of meters, height of several meters and they migrate over the sandy bed of continental shelf seas with several meters per year. They are often dredged for sand extraction, maintaining navigation depths or cable and pipeline burial in offshore wind farms. However, little is known on how sand waves respond to such perturbations. Observations in the Seto Inland Sea in Japan (Katoh et al., 1998) and model experiments of Campmans et al. (2021) suggest that sand waves tend to recover after dredging. This hypothesis is tested by the analysis of high resolution multibeam bathymetry data of three areas in the Belgian part of the North Sea. These three areas have been subject to sand extraction and were frequently surveyed, which continued in the years after extraction had ceased. From these observations, the time evolution of sand wave height, length, width, orientation and migration is determined. In one of the three sites, tidal sand wave height increased in the 10 years after closure. The other two sites show no sign of sand wave growth yet. These observations will be discussed considering the different environmental characteristics of these three sites: grain size, water depth, tidal characteristics, and the presence of smaller and larger bed forms.

References
Campmans, G., Roos, P., Van der Sleen, N., & Hulscher, S. (2021). Modeling tidal sand wave recovery after dredging: effect of different types of dredging strategies. Coastal engineering, 165, 103862.

Katoh, K., Kume, H., Kuroki, K., & Hasegawa, J. (1998). The Develop- ment of Sand Waves and the Maintenance of Navigation Channels in the Bisanseto Sea. Coastal Engineering ’98, ACSE, Reston, VA, 3490–3502. doi: 10.1061/9780784404119.265
Forest clear-cutting effects on greenhouse gas dynamics in riparian buffer zones
Authors: Klaus Marcus , Machacova Katerina , Falk Alice , Wallin Marcus , Soosaar Kaidoo , Öquist Mats
Published: March 2022

Soils play an important role in the Earth's greenhouse gas cycle. The gas dynamics in soils are tightly coupled to gas dynamics in plants, trees, and surface waters. Riparian soils receive and process solutes leaching from upland areas and act as crucial buffers of land-use effects on various ecological and biogeochemical properties of surface waters. However, their role in greenhouse gas cycling is poorly understood. Forest clear-cutting often increases the leaching of organic carbon, nutrients and greenhouse gases in groundwater. Unfortunately, the fate of these substances on their way from upland clear-cut areas through riparian forest buffer zones left along streams after clear-cutting is unknown, but highly relevant for watershed-scale greenhouse gas budgets. Here, we performed a watershed-scale experiment to investigate the effect of clear-cutting on greenhouse gas dynamics in riparian forest buffer zones in a Swedish boreal headwater catchment. The experiment included weekly to monthly sampling during April-October before (2020) and after (2021) forest clear-cutting performed in February 2021, and included a treatment watershed and an untreated reference watershed. We measured concentrations of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in soils using gas probes installed at various depths within the zone of groundwater level fluctuations along four transects from the clear-cut area through riparian forest buffer zones to near-stream sites. We also measured fluxes of these gases between the atmosphere and the forest floor, as well as tree stems, using flux chamber techniques. Initial results suggest that the clear-cutting increased CO2 and CH4 concentrations in clear-cut soils and the center of riparian buffer zones, but not in near-stream sites. In contrast, the concentrations of N2O in soils were not affected by forest clear-cutting across the full transects. In terms of greenhouse gas exchange with the atmosphere, the clear-cutting did not affect CO2, CH4 and N2O fluxes at the forest floor. Tree stems were consistent emitters of CO2 and CH4 in 2021, but the clear-cut effect remains unclear due to missing reference data before the clear-cut. Together, these results suggest that the clear-cut induced excess of CO2 and CH4 in upland groundwater was likely consumed in riparian soils or emitted through tree stems, assuming that upland and riparian soils were hydrologically connected. Our results stress the potential importance of riparian buffer zones in mediating clear-cut effects on catchment-scale greenhouse gas budgets.
High-impact weather events in Greece: Analysis of the period 2000-2020
Authors: Papagiannaki Katerina , Kotroni Vassiliki , Lagouvardos Konstantinos , Bezes Antonis
Published: March 2022

The subject of this presentation is the assessment of the occurrence, intensity, and impact severity of weather-related events with socio-economic implications during the period 2000-2020 in Greece. The aim is to draw critical conclusions through the distribution of events at the temporal and spatial level and in relation to their societal impact as measured by a qualitative impact-severity index. The data derived from the High Impact Weather Events (HIWE) database that has been developed by the METEO Unit at the National Observatory of Athens (NOA), is systematically updated and publicly available. The analysis includes events related to floods, lightning activity, hail, snow/frost, windstorms, and tornados having caused impacts on life (injury or death) and/or infrastructure. The presentation provides an overview of the data used and methodology applied for assessing weather-related hazards, and the results of their analysis that include the evolution of events, the most damaging phenomena, and the areas most exposed to each phenomenon. This work was conducted in the frame of CLIMPACT – National Νetwork on Climate Change and its Impacts, a flagship initiative on climate change to coordinate a Pan-Hellenic network of institutions.
Huge variations in the terpene emission potentials of Norway spruce
Authors: Hellén Heidi , Praplan Arnaud , Schallhart Simon , Tykkä Toni , Thomas Steven , Helin Aku , Taipale Ditte , Bäck Jaana , Hakola Hannele
Published: March 2022

Norway Spruce dominates Europe’s Boreal and sub-Alpine coniferous forests and is widely planted in southeastern Canada, in the northeastern United States, in the Rocky Mountains, and in the Pacific Coast region. Therefore it is expected to have significant contribution to emissions of biogenic volatile organic compounds. There are studies on isoprene, monoterpene and sesquiterpene emissions of Norway spruce, but emission potentials and composition vary a lot. Especially the emission potentials of sesquiterpenes are highly varying. When considering the atmospheric impact of biogenic emissions, it is essential to know their composition since, for example, aerosol formation potential of different compounds varies a lot.

In this study, we compiled all available data for Norway spruce emissions that could be used for emission potential calculations of terpenes and searched if growing location, season, or age of the tree could explain the variations. In addition to previously published data, we included new data from a boreal forest in southern Finland from 2019 and 2021 and a sub-Arctic boreal forest in northern Finland from 2020.

The differences between various trees and sites were huge, but variations of emission potentials, especially for sesquiterpenes, over the growing season were also high, even for the same tree.  Emission potentials of isoprene, monoterpenes and sesquiterpenes varied between 5 – 2500, 25 – 3200 and 42 – 15000 ng g(dw)-1 h-1, respectively. No clear trend could be observed on the basis of our measurements and other relevant studies. However, there were indication of some phenomena, e.g., none of the young trees emitted isoprene while some older trees had huge isoprene emissions.  It is also noteworthy that sesquiterpene emission rates greatly increase at the end of a growing season.
Machine learning and meteorological data for spatio-temporal prediction of tropospheric parameters
Authors: Crocetti Laura , Soja Benedikt , Kłopotek Grzegorz , Awadaljeed Mudathir , Rothacher Markus , See Linda , Weinacker Rudi , Sturn Tobias , McCallum Ian , Navarro Vicente
Published: March 2022

Radio signals transmitted by Global Navigation Satellite System (GNSS) satellites propagate through the atmosphere before being received on Earth. Thereby, the signal is delayed and tropospheric parameters can be estimated. The good global coverage of GNSS receivers, combined with the high temporal resolution and the high accuracy, make GNSS a suitable tool for studies on the atmosphere.

Atmospheric delays are differentiated into a zenith hydrostatic (ZHD) and a non-hydrostatic, or zenith wet delay (ZWD). The hydrostatic part has a larger contribution (causing a delay of roughly 2.4 meters in the zenith direction) but can be modeled with sufficient accuracy using analytical methods. The ZWD has a smaller contribution (causing a delay between 0 to 40 centimeters) and depends mainly on the water vapour content in the atmosphere. However, due to the variable nature of water vapour, the ZWD is difficult to model and is therefore typically estimated. Its quantification is essential since it drives weather systems and climate change to a great extent. For many applications, such as weather forecasting or positioning using low-cost GNSS receivers such as smartphones, global real-time monitoring or even predictions of ZWD would be required and be beneficial.

In the last decade, machine learning (ML) algorithms have gained a lot of interest and are successfully utilized in many different fields. Thereby, ML algorithms have proven to be able to efficiently process and combine large amounts of data and solve problems of various kinds.

This motivated us to investigate the feasibility of ML algorithms for the prediction of tropospheric parameters, in particular ZWD, with the help of meteorological data such as the water vapour content. The work aims to develop a global model capable of predicting ZWD in space and time. Therefore, different ML algorithms are used to train a model based on meteorological features. The performance of the utilized algorithms is evaluated based on commonly used performance metrics, such as Root Mean Squared Error (RMSE) and R².

Preliminary investigations are carried out utilizing 3000 GNSS stations distributed over Europe. The performance of various ML methods, such as Linear Regression methods, Random Forest, (Extreme) Gradient Boosting, and Multilayer Perceptron is compared. Furthermore, different feature combinations, as well as training sample sizes are investigated. It is revealed that linear methods are not able to properly reflect the observations. Instead, our Random Forest approach provides, so far, the highest model accuracy with an RMSE of 1.7 centimeters and an R² value of 0.88.
Exploring impacts of absorbing aerosol layers on underlying stratocumulus clouds using large-eddy simulation with explicit aerosol-radiation interactions.
Authors: Baró Pérez Alejandro , Ekman Annica , Schwarz Matthias , Savre Julien , Bender Frida , Devasthale Abhay , Tonttila Juha , Kokkola Harri
Published: March 2022

Biomass-burning aerosol layers overlaying stratocumulus clouds are frequent over the Southeast Atlantic during the southern African fire season (June-October). This scenario can trigger a rich set of aerosol-cloud-radiation interactions with climatic consequences that are still poorly quantified. Although satellites and in-situ measurements provide useful information on these situations, the covariance between aerosols and meteorology makes it difficult to disentangle any causal aerosol impacts on stratocumulus clouds, a problem that can be avoided when using models. In this work, we have incorporated aerosol-radiation interactions into the large-eddy simulation code MIMICAV5 to study how a biomass burning aerosol layer (composed of black carbon and organic carbon) affects an underlying stratocumulus cloud over the Southeast Atlantic. More specifically, we explore how the arrival time (time of the day during the simulation) of the absorbing aerosol layer cloud affects the underlying stratocumulus cloud properties. In addition, we explore the susceptibility of cloud droplet number concentration in the stratocumulus cloud to the absorbing aerosol number concentration above the cloud.
Transient rheology of the continental crust
Authors: Masuti Sagar , Muto Jun , Rybacki Erik
Published: March 2022

Postseismic relaxation after large earthquakes induces transient deformation of the solid Earth, particularly in the deeper part of the crust. The deformation of the upper and lower crust are mainly controlled by the rheological behavior of quartz and feldspar, respectively. The mechanical properties of quartz and feldspar at steady-state creep conditions are well constrained and flow law parameters are known from experimental calibrations. However, the physical mechanism underlying transient creep is poorly understood and the corresponding flow law parameters are unknown so far. Here, we constrain a constitutive framework that captures transient creep and steady state creep consistently using the mechanical data from laboratory experiments. The constitutive framework represents a Burgers assembly with a thermally activated nonlinear stress versus strain-rate relationship for the dashpots. Using the Markov chain Monte Carlo (MCMC) method, we uniquely determine the flow law parameters for both quartz and feldspar. We find an activation energy of 70±20 kJ/mol and a stress exponent of 2.0±0.1 for transient creep of quartz. For feldspar, the best-fit activation energies are 280±30 and 220±20 kJ/mol with stress exponents of 1.0±0.2 and 0.9±0.1 under mid- and high-temperature conditions, respectively. The stress exponents and activation energies of transient creep are consistently smaller than those of steady-state creep for both quartz and feldspar. The flow law parameters determined in this study could be used to quantify the contribution of transient creep in the postseismic deformation following a large continental earthquake. 
VULCANOPOLY: playing towards a better future
Authors: Misiti Valeria , Di Nezza Maria , Riposati Daniela , Di Laura Francesca , Battelli Patrizia , Crescimbene Massimo
Published: March 2022

The goal of scientific dissemination is to reach all levels of age and social origin of the population, simplifying scientific concepts and making them appealing to the general public.A common and understandable language has always been the visual one, for this reason many authors use images as a tool to convey scientific notions and discoveries. From its origins, science has placed images at the center of its communication processes: drawings, diagrams and then, subsequently to scientific discoveries, photographs, films up to satellite images.In this framework, we emphasize the importance of playful-didactic activity and visual language to facilitate learning and, in particular the development of scientific games. Our working group has been collaborating for years in the organization of dissemination events with the aim of increasing knowledge on the major geological issues for the protection of the planet.In this context it is important to highlight the role of scientific dissemination and the different methodologies to be used.One of the most used and appreciated tools has been the creation of scientific-didactic games: to simplify concepts, the game has in fact proved to be a fundamental tool.We present VULCANOPOLI, inserted in a series of science games that started with MAREOPOLI (Locritani et al. 2017) and inspired by Hasbro’s famous MONOPOLY. The main topic is volcanoes, both from a scientific and a historical point of view. Thanks to this game the historical evolution of some of the most important Italian Volcanoes can be reconstructed. The rules are those of the original game with some additional questions and concepts to remember, to conquer cities and accumulate points. The VULCANOPOLY game-board consists of thirty-six spaces containing twenty-one villages and cities on three main italian active volcanoes (Mount Vesuvius, Mount Etna and Stromboli Island) and one quiescent volcano (Colli Albani Volcanic District), four Chance spaces and four Community Chest spaces, a hot water baths space, a geothermal energy space, an underpass space, and the four corner squares: GO, Viewpoint, Magma Chamber and Connecting way. A deck of thirty-two Chance and Community Chest cards (sixteen each) which players draw when they land on the corresponding squares of the track, and follow the instructions and myths, legends and folklore tales  based on real events printed on them.Each time a player's token lands on or passes over GO, whether by throw of the dice or by drawing a card, the Volcanologist gives that player a volcanic rock (basalte, tuff, pozzolana, pumice, obsidian, scoria). The game can be played at secondary schools with the participation of INGV researchers. The game follows the same rules as the MONOPOLY but mediated by the presence of a researcher. 
Fire prevents the regrowth of the Amazon rainforest after complete deforestation in a fire-enabled Earth system model
Authors: Drüke Markus , von Bloh Werner , Sakschewski Boris , Lucht Wolfgang , Thonicke Kirsten
Published: March 2022

The terrestrial biosphere is exposed to land use and anthropogenic climate change, which not only affects vegetation dynamics, but also changes land-atmosphere feedbacks. In particular, tropical rainforests are endangered by anthropogenic activities and are recognized as one of the terrestrial tipping elements. An ecosystem regime change to a new state could have profound impacts on regional and global climate, once the biome has transitioned from a forest into a savanna or grassland state. Fire is a potentially major driver in the position of the transition boundary and could hence impact the dynamic equilibrium between these possible vegetation states under a changing climate. However, systematic tests of fire-controlled tipping points and hysteretic behaviour using comprehensive Earth system models are still lacking.

Here, we specifically test the recovery of the Amazon rainforest after a complete deforestation at different atmospheric CO2 levels, by using the Earth system model CM2Mc-LPJmL v1.0 with a state-of-the-art representation of vegetation dynamics and fire. We find that fire prevents large-scale forest regrowth after complete deforestation and locks large parts of the Amazon in a stable grassland state. While slightly elevated atmospheric CO2 values had beneficial effects on the forest regrowth efficiency due to the fertilization effect, larger CO2 amounts further hampered the regrowth due to increasing heat stress. In a no-fire control experiment the Amazon rainforest recovered after 250 years to nearly its original extent at various atmospheric CO2 forcing levels. This study highlights the potential of comprehensive fire-enabled Earth system models to investigate and quantify tipping points and their feedback on regional and global climate.
PARASO, a circum-Antarctic fully-coupled ice-sheet - ocean - sea-ice - atmosphere - land model involving f.ETISh1.7, NEMO3.6, LIM3.6, COSMO5.0 and CLM4.5
Authors: Marchi Sylvain , Pelletier Charles , Fichefet Thierry , Goosse Hugues , Haubner Konstanze , Helsen Samuel , Huot Pierre-Vincent , Kittel Christoph , Klein François , van Lipzig Nicole P. M. , Massonnet François , Mathiot Pierre , Moravveji Ehsan , Moreno-Chamarro Eduardo , Ortega Pablo , Pattyn Frank , Souverijns Niels , Van Achter Guillian , Vanden Broucke Sam , Verfaillie Deborah , Le Clech Sébastien , Vanhulle Alexander , Zipf Lars
Published: March 2022

How well is the Antarctic climate over the last decades represented in climate models and how predictable is its future evolution? These questions delve into the specificities of the Antarctic climate, a system characterized by large natural fluctuations and complex interactions between the ice sheet, ocean, sea ice and atmosphere. The PARAMOUR project aims at improving our understanding of key processes which control the variability and predictability of the Antarctic climate at the decadal timescale. In this context, we introduce PARASO, a novel fully-coupled regional ocean - sea-ice - ice-sheet - atmosphere climate model over an Antarctic circumpolar domain covering the full Southern Ocean. The state-of-the-art models used are f.ETISh1.7 (ice sheet), NEMO3.6 (ocean), LIM3.6 (sea ice), COSMO5.0 (atmosphere) and CLM4.5 (land), which are run at a horizontal resolution close to 1/4°. One key feature of this tool resides in a novel two-way coupling interface for representing the ocean - ice-sheet interactions, through explicitly resolved ice-shelf cavities. We also consider the impact of atmospheric processes on the Antarctic ice sheet through surface mass exchanges between COSMO-CLM and f.ETISh. Our developments include a new surface tiling approach to combine open-ocean and sea-ice covered cells within COSMO. Using a 30 year-long run, we investigate the model performance and the interannual-to-decadal variability of the simulated Antarctic climate. The focus is on the interactions between the atmosphere, ocean and ice components at the regional scale and the links with larger spatial scales. Specific attention is paid to the mass balance of ice sheets and ice shelves, which influences both the ice sheet dynamics and the changes in the ocean and atmosphere. The system and its performance will be documented in this presentation together with some aspects of decadal variability from a 30-year integration forced with reanalyses (ERA5 and ORAS5). Early results of a 3-member retrospective forecast driven by EC-Earth will also be presented.
Assessing the impact of climate change on Southeast Asia’s hydropower availability
Authors: Galelli Stefano , Dang Thanh Duc
Published: March 2022

Southeast Asia’s electricity supply largely depends on the hydropower resources of the Mekong, Chao Phraya, Irrawaddy, and Salween River Basins. Uncertain precipitation patterns, rising temperature, and other climate-driven changes are exposing these resources to unprecedented risks, prompting decision makers to re-evaluate existing reservoir management strategies through climate change risk assessments. These assessments are important in shaping the operators’ response to hydro-climatic variability and are necessary to ensure energy security in the region. In this study, we developed high-resolution, semi-distributed hydrological models to examine the potential changes of hydropower availability under projected future climate scenarios in the four largest river basins in South East Asia. Specifically, we relied on a novel variant of the Variable Infiltration Capacity (VIC) model that integrates reservoir operations into the routing scheme, warranting a more accurate representation of cascade reservoir systems. Climate change impacts were derived from the outputs of five Global Circulation Models (GCMs) forced by two Shared Socioeconomic Pathways (SSPs 2.6 and 8.5) emission scenarios in the Coupled Model Intercomparison Project Phase 6 (CMIP6). We find that hydropower generation would be altered significantly in all scenarios in terms of temporal variability and magnitude due to the changes in duration and magnitude of the summer monsoon. Our findings further stress the importance of exploring how the impact of climate change on hydropower availability propagates through water-energy systems and call for adaptive reservoir operation strategies.
Alkalinity supports gross primary production in a deep hardwater lake
Authors: Perolo Pascal , Escoffier Nicolas , Chmiel Hannah Elisa , Many Gaël , Bouffard Damien , Perga Marie-Elodie
Published: March 2022

Dissolved inorganic carbon (DIC) is rarely regarded as a limiting factor of gross primary production (GPP) because atmospheric CO2 invasion is expected to compensate for the DIC demands at high GPP levels. However, from May to August, the CO2 concentrations in the surface waters of Lake Geneva, a large and deep hardwater lake, can be as low as 100 ppm, i.e. threshold values for carbon limitation of gross primary production (GPP). Because GPP values remain high during summer in Lake Geneva, we questioned whether CO2 invasion was sufficient to supply GPP in inorganic carbon, or whether additional inorganic carbon was supplied by alkalinity, through CO2 released by the background calcite precipitation. Using the paired O2–CO2 departure from the atmospheric equilibrium coupled to alkalinity data in littoral and pelagic environments, we investigated the sources of the inorganic carbon fixed by primary production, along three hypotheses. The first hypothesis (H1) is that atmospheric CO2 invasion is sufficient to compensate for the CO2 demand. The second hypothesis (H2) builds on H1 while including the chemical enhancement of CO2 influxes. The third hypothesis (H3) consists in adding to H2 CO2 released by calcite precipitation. We find first that daily molar changes in DO are unrelated to daily molar changes in CO2, but to molar changes in alkalinity for most of the warm season. For days for which we could compute GPP, we found that for GPP < 30 µmol C L–1 d–1, H1 and H2 are sufficient to maintain the CO2 demand, in both the littoral and pelagic habitats. Above 30 µmol C L–1 d–1, even chemically enhanced CO2 invasion cannot compensate for GPP, and CO2 demand can only be meet adding CO2 supplied by alkalinity through calcite precipitation. In Lake Geneva, alkalinity could thus supply inorganic carbon to high GPP up to ~ 40% during the stratified season for littoral and pelagic primary producers.
Seasonal and Interannual Variability of the South Indian Ocean Sea Surface Salinity Maximum
Authors: Bingham Frederick , Gordon Arnold , Brodnitz Susannah
Published: March 2022

The sea surface salinity (SSS) maximum of the South Indian Ocean (the SISSS-max) is a large, oblong, high-salinity feature centered at 30degS, 90degE, at the center of the South Indian subtropical gyre. It is located poleward of a region of strong evaporation and weak precipitation. Using a number of different satellite and in situ datasets, we track changes in this feature since the beginning of the Argo era in the early 2000's. The centroid of the SISSS-max moves seasonally north and south, furthest north in late winter and farthest south in late summer. Interannually, the SISSS-max has moved on a northeast-southwest path about 1500 km in length. The size and maximum SSS of the feature vary in tandem with this motion. It gets larger (smaller) and saltier (fresher) as it moves to the northeast (southwest) closer to (further from) the area of strongest surface freshwater flux. The area of the SISSS-max almost doubles from its smallest to largest extent. It was maximum in area in 2006, decreased steadily until it reached a minimum in 2013, and then increased again. The seasonal variability of the SISSS-max is controlled by the changes that occur on its poleward, or southern, side, whereas intereannual variability is controlled by changes on its equatorward side. The variations in the SISSS-max are a complex dance between changes in evaporation, precipitation, wind forcing, gyre-scale ocean circulation and downward Ekman pumping. Its motion correlated with SSS changes throughout the South Indian Ocean and is a sensitive indicator of changes in the basin's subtropical circulation.
Discovery of scattered subvolcanic complexes that feeded the volcanism in the area of Etna
Authors: Barberi Graziella , Patanè Domenico , Scarfì Luciano , Coltelli Mauro
Published: March 2022

In this work we present a new tomographic inversion of the velocity structure and hypocenter parameters at Mt. Etna, carried out by the larger seismic dataset never used than to the previous tomographies. The result of tomographic inversion, including the 3D distributions of P and S velocities, Vp/Vs ratio, and accurate source locations, has been obtained based on the integration of active seismic data (151.403 P-phases from 4.112 shots) acquired during the 2014 TOMO-ETNA experiment (EC-FP7 MED-SUV and EUROFLEET2 MED-SUV.ISES projects) and 10.955 selected local earthquakes data (218.473 P-phases and 39.073 S-phases), recorded by a total number of 262 stations of the INGV permanent seismic network and from the onland and OBS temporary network. For the inversion we used the tomoDDPS algorithm [Zhang et al., 2009] and the input velocity model previously obtained with the PARTOS code (Moreno et al. 2016), considering a total number of 1.580.343 P and 228.663 S differential times.

Based on our data selection and inversion strategy, we obtain a strongly improved 3-D high-resolution Vp, Vs and Vp/Vs models both onland and offshore the volcano, discovering for the first time, in the peripherical part of the edifice: i) on-land, the presence of two subvolcanic complexes in the south-eastern and southern flanks, west to Acicastello-Acitrezza and Paternò and Motta, respectively, where the Etna’s ancient volcanisms (500 to 110 ka) manifested and ii) the presence of a ca. N-S oriented high velocity anomaly (5.0-6.5 km/s) located offshore southeast of Etna area, suggesting a clear interplay between submarine volcanic manifestations and tectonic setting. This body extending from about the sea level to ca. 8 km b.s.l. confirms the observation of a large and intense magnetic positive anomaly (>700 nT) related to deep sources (Cavallaro et al., 2016), evidenced by the magnetic survey carried out during TOMO-ETNA.

 
Coupling process-based models and remote sensing data to predict yield loss by hail damage
Authors: Longo Matteo , Furlanetto Jacopo , Dal Ferro Nicola , Caceffo Daniele , Morari Francesco
Published: March 2022

Hailstorm damage in agriculture often results in considerable loss in harvestable product. Currently, crop damage is quantified by insurance companies through field inspectors’ assessment, a time-consuming activity that is potentially affected by estimation errors over large areas. Coupling remote sensing and crop modeling represents a promising solution for the crop insurance market for a reliable, objective, and less labor-intensive method to estimate hail damage. With the general aim of developing an automated platform that can identify crop yield failure at field level, the Ceres-Maize (DSSAT v 4.7.5) model was integrated with remote sensing data to reproduce maize growth and production dynamics. A two-year experiment was established at the Ca’ Tron farm on the low lying of Veneto Plain (NE Italy). The crop damage was performed using a custom-made machine at three intensities (low, medium, and high) depending on crop defoliation and four plant growing stages (early vegetative, flowering, early-milky, and dough stages). Each treatment was replicated three times on plots of 20x20 or 60x60m. Additional four subplots with no damage were used as control. Leaf area index (LAI) and biomass were measured after each damage event. LAI was estimated from both drone-borne multispectral sensors and satellites imageries (Sentinel-2), and ground-validated using a ceptometer. The Ceres-Maize model was used to predict obtainable and potential crop yields: 1. by embedding the estimated LAI reduction at the time of damage into the “PEST” sub-model; 2. by calibrating the model seasonal LAI dynamics using the drone- and Sentinel-based LAI observations over the cropping season. The first year of the experiment was used to calibrate DSSAT, the second one to validate its performance.

Results showed a satisfactory agreement between measured and simulated Ceres-Maize LAI dynamics. The final yields were also well reproduced among treatments. On the other hand, the model did not fully capture the residue biomass and the harvest index. Assimilating remote-sensing-based parameters in crop models appears to have promising benefits for the insurance market, providing more robust and less time-consuming methodologies.
A cost sharing approach to flood risk management decision-making
Authors: Walder Stefan
Published: March 2022

The flood event of August 2005 at the river Inn and the actual hazard zone mapping indicated a need for flood protection in the Lower Inn Valley in Tyrol (Austria). To ensure an appropriate protection of settlements, industrial areas and infrastructure up to a return period of 100 years, extensive planning activities for protection and compensation measurements were initiated. In accordance with the Austrian Water Law, a so-called water association was established to bundle decision-making, planning and financing of all protection measurements. The members of the water association are the affected communities and the local operators of infrastructure.
The majority of the cost of flood protection is carried by the federal and state government in Austria. The remaining cost in the Lower Inn Valley has to be divided between the members of the water association.
In order to guarantee a reasonable and fair distribution of costs, as well as voting rights, a specific approach for cost sharing was developed. The allocation of costs and voting rights is based on the protected area and the length of the protected riverbank in the communities. The areas were categorized by actual land use and by the intensity of an expected flood event and weighted respectively in the assessment. Further, the costs for communities were reduced for contributing compensatory measures, such as flood retention space. Operators of infrastructure contribute a fixed share.
In addition to the technical aspects of flood risk management and socio-economic aspects, an essential component in the decision-making is the cost and vote distribution of the affected communities, which thus has far-reaching influence on the entire project.

In this contribution we will detail the fair and specific approach for cost and vote sharing and provide an overview over the process that led to the foundation of the water association. We will report difficulties and the consequences of the chosen approach and give an outlook on the future of the project.
Strain localization in quartz-rich fault gouge at subseismic slip rates
Authors: Hung Chien-Cheng , Niemeijer André
Published: March 2022

Understanding strain localization and development of shear fabrics within brittle fault zones at subseismic slip rates is crucial as they have critical implications for the mechanical strength and stability of faults and for earthquake physics. We performed direct shear experiments on ~1 mm thick layers of simulated quartz-rich fault gouge at an effective normal stress of 40 MPa, pore fluid pressure of 15 MPa, and temperature of 100°C. Microstructures were analyzed from strain hardening state (~1.3 mm displacement) to strain softening (~3.3 mm displacement) to steady-state (~5.6 mm) at different imposed shearing velocities of 1 µm/s, 30 µm/s, and 1 mm/s. We performed X-ray Computed Tomography (XCT) on sheared samples with a strain marker to analyze slip partitioning. To analyze and quantify localization from few hundreds to thousands of cross-section images, we used machine learning and developed an automatic boundary detection method to identify the type of shear fabrics and quantify the amount of them. Our results reveal that R1 and Y (or boundary) shears are the two major localization features that developed in a repeatable manner. Slip on R1 shears shows little dependency on both shear displacement and slip velocity and amounts to ~5 to ~30% of slip through the entire frictional sliding. On the other hand, Y and boundary shears show a strong correlation with displacement and velocity where more than 40% of strain was accommodated at steady-state for all velocities. However, Y and boundary shears become less prominent with increasing velocity, suggesting that velocity-weakening and the associated nucleation of unstable sliding are less likely to occur at higher slip rates as the overall friction behavior would be controlled by a thicker gouge layer. In other words, this suggests that Y shear development by grain size reduction is less efficient at high slip velocities which has important implications for the amount of heat generated during accelerating slip.
A comprehensive Earth System Model (AWI-ESM) with interactive ice sheets and icebergs: A step towards realistic freshwater fluxes for abrupt climate change scenarios
Authors: Ackermann Lars , Rackow Thomas , Himstedt Kai , Gierz Paul , Knorr Gregor , Lohmann Gerrit
Published: March 2022

Icebergs play a crucial role in Earth's climate system. They transport large amounts of fresh water and alter ocean salinity, affect sea-ice formation, and can lead to abrupt climate changes in the past. Hence, a proper representation of icebergs in Earth system models (ESMs) is essential to improve the understanding of processes involved in abrupt climate changes. Despite their importance, icebergs are rarely represented in ESMs. Freshwater fluxes are often parameterized, neglecting the transport via ocean currents and the heat loss due to iceberg melting. Other models that use an interactive iceberg component are typically ocean-only models, do not represent ice sheets and the atmospheric component explicitly, or are models of intermediate complexity. One reason for this deficiency is the considerable computational costs related to iceberg modeling.

Here, we present the latest version of the Alfred Wegener Institute-Earth System Model (AWI-ESM) with interactive ice sheets and a Lagrangian iceberg model. The iceberg component runs as a submodel of the ocean–sea-ice model FESOM2 with an asynchronous coupling to enable computationally effective simulations with the iceberg-enhanced coupled model. Total execution times can be strongly reduced compared to a non-overlapping execution of the iceberg model with other components. Iceberg meltwater and the associated heat fluxes are coupled to the ocean. The ice sheet is dynamically coupled to the climate components. A new feature of this model setup is the ice sheet-iceberg coupling: Icebergs are drawn from a specific size distribution to match the calving output of the ice sheet model in regions of iceberg discharge. Therefore, discharge-related freshwater fluxes are represented more realistically than in other ESMs.
How are air and land temperatures affected by the horizontal resolution and the bulk urban parametrisation in WRF model simulations over the eastern Mediterranean and the Middle East?
Authors: Constantinidou Katiana , Hadjinicolaou Panos , Tzyrkalli Anna , Zittis George , Lelieveld Jos
Published: March 2022

Urbanization alters land surface properties and the local surface energy balance and, therefore, land and near surface air temperature. Urban morphology and processes are represented in climate models using urban land-surface models with varying levels of complexity, which parameterise the effects of urban environments on surface fluxes without representing buildings explicitly.

This study focuses on the eastern Mediterranean and the Middle East (EMME) area over which the effect of urban parameterisation and resolution difference on simulated 2-meter air and land surface temperatures is investigated. Two high-resolution simulations at 16 km and 4 km are performed over the EMME domain using the Weather Research and Forecasting (WRF) model coupled with NoahMP land surface scheme for the period of 2000-2002. The bulk urban parameterisation scheme is implemented, which assigns fixed values for land properties such as surface albedo, roughness length etc., appropriate for the resolved urban areas. Focusing on several cities of the region of interest for the summer season (June-July-August, JJA), the effect of the model horizontal resolution and the grid-box land type on air (minimum and maximum) and land temperatures is examined. The temperature difference of the urban-characterised grid-boxes compared to their rural surroundings is also studied. Station (Integrated Surface Dataset - ISD) and satellite (MODIS-TERRA) observations together with reanalysis data (ERA5-LAND) are used for the evaluation of the simulation output.
Vulnerability of aquifers on volcanic islands: the case of La Palma and El Hierro (Canary Islands, Spain) 
Authors: Santamarta Juan C. , Cruz-Pérez Noelia , Rodríguez-Martín Jesica , Marazuela Miguel Ángel , Álvarez-Vázquez Rosana , García-Gil Alejandro
Published: March 2022

The outermost regions of Europe are nine: Guadeloupe, French Guiana, Martinique, Mayotte, Reunion and Saint Martin (France), the Canary Islands (Spain), the Azores and Madeira (Portugal). These regions enrich the EU economically, culturally and geographically, hosting 80% of its biodiversity. However, due to their remoteness and other unique features, they pose challenges for their development. The particular case of the Canary Islands will be developed in the framework of the European H2020 project Arsinoe, where the hydrological cycle and agriculture in the Canary archipelago will be studied in El Hierro and La Palma. These two islands have been selected for the following reasons: i) El Hierro is a pioneer in presenting a self-sufficient energy model (La Gorona del Viento project) and is rich in groundwater, this being the most used water resource on the island; ii) La Palma has been selected because it is an island rich in groundwater (in fact, it is the only island in the Canary archipelago that does not have desalination plants) and where agriculture is very important (especially tropical crops such as banana, mango, avocado, etc.) and, due to the volcanic eruption that began in September 2021, the situation of the aquifer is uncertain, something that is worrying since La Palma depends on groundwater resources to guarantee the water demand of agriculture, local population and tourism. The effect of the eruption on the vulnerability of the aquifer of La Palma is still unknown, so it is desired to study in depth the effects on the aquifer in quantitative and qualitative terms therefore, ARSINOE will focus on the ecological transition and vulnerability of aquifers in volcanic islands and will put further efforts to the primary production including agriculture, forestry, fisheries and aquaculture, water management and clean energy infrastructure. ARSINOE will take into account the interdependence between water and agriculture. The agricultural sector is the largest water user in the Canary Islands, where wine, potatoes and tomatoes are the main exports. Therefore, greater sustainability within the water sector (through the water footprint and the carbon footprint) will positively affect the agricultural sector and, therefore, the water and energy situation of the archipelago. But aquifers of both islands are also at risk due to other circumstances, specifically those derived from climate change: greater saline intrusion (due to rising sea levels), losses in freshwater inputs (due to decreased rainfall), changes in physic-chemical conditions of all water bodies… All these effects will be studied on both islands, through the ARSINOE Project, and from a local point of view. 
Multiparametric perspective of the North Atlantic eddy-driven jet: configurations, regional impacts and remote drivers
Authors: Barriopedro David , García-Burgos Marina , Ayarzagüena Blanca , García-Herrera Ricardo
Published: March 2022

The North Atlantic eddy-driven jet (EDJ) is the most outstanding component of the Euro-Atlantic atmospheric circulation. Classically, the winter EDJ variability has been described in terms of latitude and intensity. However, this classification has recently been shown as incomplete to fully characterize more complex EDJ states. For instance, the three well established latitudinal states of the EDJ do not match the four preferred flow regimes of the Euro-Atlantic sector. A possible solution to this trouble would be the additional consideration of other EDJ characteristics, such as the tilt, waviness or longitudinal extension among others, but this has not been investigated yet. 

This study presents a set of daily parameters of the North Atlantic EDJ that allows for a dissection of the EDJ structure beyond the well-established trimodality in reanalysis data. The set is composed by intensity, sharpness, position, latitudinal boundaries, longitudinal extension, tilt and zonal asymmetries, which provides a manageable treatment of EDJ configurations without the need of high-dimensional 2-D fields. The parameters are computed through new developed diagnostics based on winter North Atlantic daily (zonal) wind, averaged between 925-700 hPa. The multi-parametric approach allowso deepen the structure of the EDJ, as well as the impacts and drivers of its variability.

Recurrent states of the EDJ are assessed via multiparametric clustering, which is able to reconstruct the trimodality of the EDJ and more complex EDJ configurations described in the literature. Furthermore, the considered parameters turn useful for the study of regional surface impacts of the EDJ, which are better explained by a combination of parameters rather than changes in individual parameters such as the jet latitude.

Lastly, the influence of a selected number of potential external drivers of the EDJ is analysed by means of linear regressions and composite analyses based on reanalysis data. The winter stratospheric vortex and previous late summer North Atlantic horseshoe are identified as the most influential drivers of different EDJ parameters, in agreement with some previous studies. However, winter snow, ice cover or sea surface temperature patterns can also affect to some extent specific parameters. These results suggest some potential predictability of the winter EDJ.