bluuebunny/crossref_metadata_2025 huggingface dataset:
N2O rate of change as a diagnostic of the Brewer-Dobson Circulation in the stratosphere
Authors: Minganti Daniele , Chabrillat Simon , Errera Quentin , Prignon Maxime , Kinnison Douglas , Garcia Rolando , Abalos Marta , Alsing Justin , Schneider Matthias , Smale Dan , Jones Nicholas , Mahieu Emmanuel
Published: March 2022

The Brewer-Dobson Circulation (BDC) determines the distribution of long-lived tracers in the stratosphere; therefore, their changes can be used to diagnose changes in the BDC. We investigate decadal (2005-2018) trends of nitrous oxide (N2O) stratospheric columns (12-40 km) as measured by four Fourier transform infrared (FTIR) ground-based instruments and by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS), and compare them with simulations by two models: a chemistry-transport model (CTM) driven by four different reanalyses, and the Whole Atmosphere Chemistry-Climate Model (WACCM). The limited sensitivity of the FTIR instruments can hide negative N2O trends in the mid-stratosphere because of the large increase in the lowermost stratosphere. When applying the ACE-FTS sampling on model datasets, the reanalyses by the European Centre for Medium Range Weather Forecast (ECMWF) compare best with ACE-FTS, but the N2O trends are consistently exaggerated. Model sensitivity tests show that while decadal N2O trends reflect changes in transport, these trends are less significant in the northern extratropics due to the larger variability of transport over timescales shorter than two years in that region. We further investigate the N2O Transformed Eulerian Mean (TEM) budget in three model datasets. The TEM analysis shows that enhanced advection affects the stratospheric N2O trends more than changes in mixing. While no ideal observational dataset currently exists, this model study of N2O trends still provides new insights about the BDC and its changes thanks to relevant sensitivity tests and the TEM analysis.
Tectonic phases in Galileo Regio, Ganymede’s dark terrain.
Authors: Rossi Costanza , Lucchetti Alice , Massironi Matteo , Pozzobon Riccardo , Penasa Luca , Munaretto Giovanni , Pajola Maurizio
Published: March 2022

The surface of Ganymede, which is the biggest satellite of Jupiter, shows strong tectonic deformation affecting both its geologic units, i.e., the younger light terrain and the older dark terrain. The dark terrain is characterized by low albedo, high crater density and furrows, which are morphotectonic structures formed by brittle deformation. Furrows are straight to curved fragments of troughs, with high albedo rims that bound a low albedo floor. Two systems have been recognized at the regional scale, which are the Lakhmu Fossae, whose furrow setting follows a concentric pattern resulting from a multi-ring impact basin, and the Zu Fossae, which follows a radial setting. In addition, local scale structures have been identified superimposed on the regional scale systems, leading to the reworking of the pristine structures. In this contribution, we investigate the tectonic evolution of the furrows in Galileo Regio (approximately from 180°-120° W to 0°-60° N), at both regional and local scale, with the identification of the tectonic events responsible for the deformation of this dark terrain. We performed a structural mapping and geostatistical analyses of the attributes of the mapped structures, such as the length, sinuosity, azimuth, spacing within the adjacent structures. Their quantification allows us to recognize a total of four structural systems within the area and to unravel the paleo-stress fields that have originated them. We prepared an evolutionary tectonic model of the furrow systems of Galileo Regio that shows the dynamics and the induced kinematics. We suggest that Galileo Regio underwent a sequence of tectonic phases associated with extensional and strike-slip regimes, these latter consistent with the kinematics that affected the light terrain of the adjacent Uruk Sulcus. This work advances the assumption that the dark terrain has been later affected by the same tectonics that deformed the light terrain and confirms the rejuvenation of the dark terrain towards a possible future transformation into light ones. The obtained results will be used for the scientific preparation of dedicated high-resolution observations that will be taken with the JANUS instrument onboard JUICE mission.
Acknowledgments: The activity has been realized under the ASI-INAF contract 2018-25-HH.0.
Ionospheric Turbulence and the Equatorial Plasma Density Irregularities: Scaling Features and RODI
Authors: De Michelis Paola , Alberti Tommaso , Coco Igino , Consolini Giuseppe , Giannattasio Fabio , Pezzopane Michael , Pignalberi Alessio , Tozzi Roberta
Published: March 2022

In the framework of space weather, the understanding of the physical mechanisms responsible for the generation of ionospheric irregularities is particularly relevant for their effects on global positioning and communication systems. Ionospheric equatorial plasma bubbles are one of the possible irregularities. Using data from the ESA’s Swarm mission, we investigate the scaling features of electron density fluctuations characterizing equatorial plasma bubbles. Results strongly support the turbulent character of these structures and suggest the existence of a clear link between the observed scaling properties and the value of the Rate Of change of electron Density Index (RODI).

In addition, considering that important features of plasma bubbles such as their dependence on latitude, longitude, solar and geomagnetic activities have been inferred indirectly using their magnetic signatures, we study also the scaling properties of the magnetic field inside them. We show that the spectral features of plasma irregularities cannot be directly inferred from their magnetic signatures. A relation more complex than the linear one is necessary to properly describe the role played by the evolution of plasma bubbles with local time and by the development of turbulent phenomena. A better comprehension of the plasma bubbles dynamics and of the turbulence processes that characterize their time evolution may benefit from the use of very high-resolution vector magnetic field and plasma density measurements such as those available from the future NanoMagSat mission.

 
Life cycles of glacial lakes in Norway: Insights from machine learning algorithms on Landsat series and Sentinel-2 
Authors: Moghaddam Ghazal , Andreassen Liss Marie , Rogozhina Irina
Published: March 2022

The observed retreat of mountain glaciers on a global scale promotes the formation and growth of glacial lakes across newly exposed ice-free areas. In mainland Norway, this process drives the rise in glacial lake outburst floods (GLOFs), posing a considerable threat to people and infrastructure  downstream. Moreover, many glacial lakes are used as reservoirs for hydropower production and thus represent an important energy source, emphasizing the need for continuous monitoring of glacial lake life cycles.

Remote sensing is currently the most efficient technique for tracking changes in glacial lakes, understanding their responses to climate change and observing lakes prone to GLOFs. Recent advances in machine learning techniques have presented new opportunities to automatize glacial lake mapping over large areas. For the first time, this study presents a Norway-wide reconstruction of glacial lake changes through the last three decades using  machine learning algorithms and long-term satellite observations. It contrasts the performance of two classification methods - maximum likelihood  classification (MLC) and support vector machine (SVM) - to outline glacial lakes and study their evolution using the Landsat series and Sentinel-2 images.

This study zooms into the pros and cons of each classification method and satellite product through the prism of glacial lake processes occurring over  disparate temporal and spatial scales - from lake formation, growth and dissociation from the proximal glaciers to the aftermath of rapid GLOF events. Based on this analysis, I conclude that the recognition skills of supervised classification methods largely depend on the quality of satellite images and careful selection of training samples. Some of the factors that adversely affect the classification results are unfavourable weather conditions such as  cloud, snow and ice cover, image disturbances through atmospheric corrections and shadows on slopes that lead to misclassifications. Regardless of higher spatial and temporal resolution, Sentinel imagery has not revealed significant advantages over Landsat but has shown a potential for their  complementary use to continue glacial lake observations in the future. The performance of SVM is clearly superior to MLC, but it is difficult to use over  large spatial scales, at least in the form it is currently implemented in ENVI.
Distribution of hydrogen peroxide over Europe during the BLUESKY aircraft campaign
Authors: Hamryszczak Zaneta , Pozzer Andrea , Obersteiner Florian , Bohn Birger , Steil Benedikt , Lelieveld Jos , Fischer Horst
Published: March 2022

Hydrogen peroxide and higher organic hydroperoxides form an important reservoir for peroxy radicals (HOx), which are key contributors to the self-cleaning processes of the atmosphere. The work gives an overview of airborne in-situ trace gas observations of hydrogen peroxide (H2O2), and methyl hydroperoxide (MHP) over Europe during the Chemistry of the Atmosphere – Field Experiments in Europe (CAFE-EU, also BLUESKY) aircraft campaign. The purpose of the campaign was to obtain an overview of the trace gas and aerosol distribution over Europe to analyze atmospheric chemistry under the conditions of the COVID-19 lock-down. The campaign anticipated to investigate the impact of reduced emissions from anthropogenic sources due to the COVID-19 pandemic on the chemistry and physics of the atmosphere. The rapid decrease of anthropogenic emissions established a unique opportunity for analysis of the changes in the atmosphere. The campaign took place in May/June 2020 over Central and Southern Europe and within the North Atlantic Flight Corridor. Airborne measurements were performed on the High Altitude and Long-range (HALO) research aircraft out of the base of operation in Oberpfaffenhofen (Germany). Average mixing ratios for H2O2 of 0.32 ± 0.25 ppbv, 0.39 ± 0.23 ppbv and 0.38 ± 0.21 ppbv within the upper and middle troposphere and the boundary layer were measured over Europe, respectively. Vertical distribution of H2O2 reveals a significant decrease above the boundary layer in comparison with previous airborne observations, most likely due to cloud scavenging and subsequent rainout. The expected maximum hydrogen peroxide mixing ratios at 3 – 7 km were not found during BLUESKY in contrast to observations during previous studies over Europe, during the campaigns HOOVER and UTOPIHAN-ACT II/III. Simulations with the global chemistry-transport model EMAC reproduce partly the impact of cloud uptake and rainout loss of H2O2. A comparison of calculated deposition loss rates based on EMAC reveals an underestimation relative to the observations. A performed sensitivity study without H2O2 scavenging underlines the major impact of cloud processing and precipitation on the hydrogen peroxide budget. Differences between simulations and observations are most likely due to difficulties in the simulation of wet scavenging.
Devolatilisation during planet formation: A hybrid model of chemistry and dynamics 
Authors: Wang Haiyang
Published: March 2022

A star and its planets are born from the same molecular cloud, so they share the same origin of the essential building blocks: elements. The compositional deviations between stars and (particularly rocky) planets are associated with the gas-dust fractionation process in the protoplanetary disk and subsequent formation processes of the planets. During these processes, a key differentiator between forming a gas giant (e.g. Jupiter) and a rocky planet (e.g. Earth) is devolatilisation – i.e. depletion of volatiles (e.g. H, C, and O) resulting in completely different bulk compositions between the two types of planets, with former being dominated by gases/ices and the latter by rocks. This devolatilisation mechanism has been empirically observed in both the Solar System and other planetary systems (e.g. in polluted white dwarf atmospheres), but has yet to be explored and implemented in the prevalent planet-formation models.

I will explore both the nebular and post-nebular devolatilization processes based on the first principals starting from the stellar nebulae to rocky planetary bodies. These processes will then be coupled with a state-of-the-art planet formation model. Such a coupled/hybrid devolatilisation-dynamics model will enable a detailed and accurate estimation of the volatile (subject to devolatilisation) and refractory (resistant to devolatilisation) contents of a small (rocky) planet, as well as the physical properties (e.g. mass, radius, and orbit) of the planet. These unprecedentedly detailed predictions of planetary elemental composition will provide crucial constraints, together with mass, radius and orbital properties, for further modelling of planetary interiors, surfaces, and atmospheres. Together, these will lead to a new level of predictive statistical understanding of the detailed properties of small (rocky) planets in our solar neighbourhood.
Mapping Wildfire Fuels, Behavior, and Hazard in a Managed Temperate Forest Using Airborne LiDAR and Sentinel-1 & -2
Authors: Heisig Johannes , Olson Edward , Pebesma Edzer
Published: March 2022

In the light of climate change both number and duration of droughts and heat waves in Central Europe are projected to increase. Such developments will affect vegetative fuels and may alter the local fire regime. Wildfire is expected to expand into new, traditionally non-fire-prone regions such as the temperate zone. While having been a negligible threat until recently, more and larger fires can be anticipated in Central Europe.

Integrated fire hazard is a valuable metric for forest and fire management and may support safety planning efforts and decision-making. It combines flame length and burn probability which can be derived from fire spread simulations. These rely on multiple spatial variables related to topography, climate and fuels. Information on fuels is thereby most challenging to acquire as they vary significantly in space and time. Modeling surface and canopy fuel variables requires extensive field data. Both can strongly benefit from incorporating remote sensing data in their prediction.

We present a comprehensive assessment of wildfire fuels, behavior and hazard for a small managed temperate forest in north-western Germany. Dominant species present include Scots pine (Pinus sylvestris), European Beech (Fagus sylvatica) and red oak (Quercus rubra). Located in a densely populated region the study area is highly frequented for recreational purposes.

Field data was collected to describe surface (n = 215) and canopy (n = 30) fuel characteristics. A total of 119 variables was extracted from airborne LiDAR point clouds and Sentinel-1 and -2 imagery. These facilitate predictive modeling of spatially continuous fuel variables at 10 meter resolution. Three surface fuel types were classified using a Random Forest model combined with a Forward Feature Selection process. Canopy Cover, Canopy Height and Crown Base Height were directly derived from LiDAR data. Crown Bulk Density was modeled through Ridge regression. The classification model scored an OA of 0.971 (Kappa: 0.967) whereas the regression model performed notably weaker (RMSE = 0.054; R² = 0.59).

We simulated fire spread from random ignitions considering an array of environmental scenarios with varying wind speed, air temperature and fuel moisture content. Results show most elevated fire hazard for high wind speeds and low fuel moisture. Further, slope and surface fuel type are relevant factors. Fires burned fastest and most frequently on slopes in large homogeneous pine stands. Therefore, preventative measures should be focused on these sites.

 
Analysis of nationwide groundwater monitoring networks using lumped groundwater models: a case study of Switzerland
Authors: Collenteur Raoul , Moeck Christian , Schirmer Mario , Birk Steffen
Published: March 2022

Many countries maintain nationwide groundwater networks to monitor the status of their groundwater resources. To assess the current water availability as well as help forecast future changes, it is fundamental to understand and predict groundwater dynamics observed in the individual monitoring wells. Nationwide monitoring networks typically cover multiple aquifer systems with different degree of environmental complexity. Understanding these aquifer systems is challenging, as the development of physically-based, distributed groundwater models is time-consuming and costly. As an attractive alternative, statistical and conceptual lumped-parameter models may be applied to analyze monitoring networks. The advantage of these models over physically-based models is that the conceptual parameterization is relatively simple and computation is efficient, while typically results are robust.

In this study, we analyze the long-term groundwater-monitoring network of Switzerland using conceptual, lumped-parameter models implemented in the Pastas software package. The 29 monitoring wells in the network are situated in unconsolidated aquifers across Switzerland, ranging from high altitude alpine aquifers to pre-alpine aquifers systems on the Swiss plateau. Given the very diverse topography in Switzerland, snowmelt processes affect some aquifers, while groundwater-surface water interactions are important in the valleys. The models are used to identify and quantify which driving forces (e.g., precipitation, river levels) control the groundwater dynamics, and how fast the groundwater systems respond to changes in these stresses. The results show that precipitation and evaporation explain large parts of the observed dynamics, while about half of the monitoring wells in the network appear to be influenced by river level fluctuations. Explicitly accounting for snow processes in the recharge generating process is found to improve the simulation of the water table dynamics for only a few wells in high-altitude aquifers. The models developed in this study lead to a better understanding of the observed groundwater dynamics across Switzerland and will be used in future studies to explore the sensitivity of the groundwater resources to climatic changes.
Investigation of ice with geophysical measurements during the transit of cryobots
Authors: Boxberg Marc S. , Simson Anna , Chen Qian , Kowalski Julia
Published: March 2022

Several icy moons of our Solar System like Jupiter’s moon Europa have a global ocean of liquid water below their icy crust. These ocean worlds are possible targets for space missions that aim to assess their potential for habitability or even to search for life. Cryobots (or ice melting probes) are suitable tools to reach the subglacial oceans for in-situ investigations. The necessary ice shell transit provides an excellent opportunity to investigate structure and composition of the ice itself by means of geophysical and other in-situ measurements. This will allow us to better understand the evolution of icy moons and their role in our solar system.

We present current ideas as well as first results from terrestrial analogue studies. Acoustic data obtained during a field test on Langenferner Glacier, Italy was used to conduct a travel time tomography, which yields insight into heterogeneities in the local acoustic wave propagation speed through the ice. The acoustic sensor set-up was originally designed for localization of the melting probe rather than an investigation of the ice structure. However, we can still show that such opportunity data can be used to obtain a wave velocity distribution which can be further interpreted with respect to ice properties like porosity.

While we already investigated the acoustic data, we evaluate the potential of other measurements. For example, Radar measurements in combination with the acoustics can be used to identify the ice-water boundary and, in addition, cracks and inclusions in the ice. Conductivity measurements provide information on the salinity. At ice-water interface regions, the salinity is in thermochemical equilibrium with the temperature and porosity of the ice. We present our concept for on-board electrical conductivity measurements and analyze its potential, for example, to constrain ice properties and to predict ice-water interfaces based on existing terrestrial field data and process models. Furthermore, some of the cryobot’s housekeeping data might be of interest for investigating the ambiance, too. For example, the temperature and the density of the ice affect the melting velocity of the cryobot, which constitutes an inverse problem to get further information on the ice.
Clubroot and soil biology – from ecology to biocontrol?
Authors: Schwelm Arne , Geisen Stefan
Published: March 2022

Interactions between plants, soil, and microbiota makes the rhizosphere of central importance for ecosystem functioning. Although non-pathogenic organism dominate this rhizobiome, plant pathogens have an important functional role for plant performance. In fact, plant pathogens trigger plant defence and alter the metabolism, nutrient flow and survival of the host, leading to changes in overall plant performance which feeds-back to the rhizobiome. However, the links between soil-borne pathogens and the rhizobiome are only starting to be explored. Here we focus on the clubroot pathogen Plasmodiophora brassicae, a pathogen that forces farmers to abandon cultivation of Brassica species for more than a decade, to decipher pathogen impact on the rhizobiome. Furthermore, we aim to identify potentially disease suppressive and disease conducive microbiome members, including bacteria, fungi, protists and animals. We are performing complex plant and soil physicochemical analyses to decipher underlying drivers of taxonomic and functional changes in the rhizobiome to clubroot infection including the impact of the detritusphere. The results of this studies will give an important insight of the ecological role of plasmodiophorid species on the plants and its rhizobiome. Additionally, by identifying pathogen suppressive and conducive soil biota new biocontrol applications can be developed that will also be useful to control other soil-borne pathogens. In this presentation we will provide the framework of the research and initial findings that provide first ideas on the importance of the plant-clubroot-rhizobiome connections.
An approach for evaluating the level of plastic residues in agricultural soils
Authors: Hernandez Manuel , Peñalver Rosa , Arroyo-Manzanares Natalia , Campillo Natalia , López-García Ignacio , Viñas Pilar
Published: March 2022

There is a continuous increase of the use of plastic materials globally, which makes difficult to manage their waste, constituting an important source of pollution for the different environmental areas. Specifically, the long-term quality and productivity of agricultural soils is affected by the contamination of these plastic residues, being these pollutants mainly present as microplastics coming from the degradation of the larger initial plastic contaminants. In addition, plastics contain different additives to improve their properties which are normally toxic organic compounds which may have a negative impact to the agricultural environment.

The purpose of this research is to develop and validate an analytical method based in a solid-liquid extraction stage followed by gas chromatography coupled to mass spectrometry (GC-MC) to determine volatile organic compounds related to plastics (monomers, additives, and degradation products) in soil samples of agricultural areas. For this purpose, a number of samples were collected in a wide zone located in the Rambla del Beal (Cartagena, Spain).

The optimized method has allowed the quantification of 14 volatile compounds, such as styrene, phthalates or bisphenol A that may be released from plastic residues, because they are monomeric species or additives. Other species associated to the degradation (environmental conditions over time) of the plastic residues such as 2,4-diterbutylphenol have been also found in the samples.

In addition, a non-targeted approach has been developed for the identification of other pollutants present in the soil samples without the use of standards. This goal was achieved by the use of the mass spectrometer detector working in the full scan mode and the application of MS database libraries (NIST and Wiley).

This analytical methodology represents a basis for a reliable evaluation of the presence of plastic pollutants in soils through the determination of their additives, monomers and degradation compounds.

 

The authors are grateful to the Spanish MICINN (Project PGC2018-098363-B-100) for financial support
Major deglaciation during the Late Glacial in coastal regions of Greenland
Authors: Garcia de Oteyza de Ciria Julia Nieves , Oliva Marc , Palacios David , Fernández-Fernández Jose Maria , Schimmelpfennig Irene , Andrés Nuria , Antoniades Dermot , Léanni Laetitia , Jomelli Vincent , Rinterknecht Vincent , Lane Tim , Team Aster
Published: March 2022

The Greenland Ice Sheet (GrIS) is a key component of the global climate system. However, our current understanding of the spatio-temporal oscillations and landscape transformation of the GrIS margins since the last glacial cycle is still incomplete. This work aims to study the deglaciation in the Zackenberg Valley, Greenland, and the origin of the derived glacial landforms. In order to reconstruct the spatial extent and geometry of past glacial phases we carried out extensive fieldwork and high-detailed geomorphological mapping, together with cosmic-ray exposure (CRE) dating to samples from erosive and depositional glacial landforms. Erratic boulders dispersed across the summits suggest that Late Quaternary glaciers filled the valleys and fjords during periods of maximum ice expansion. As glacier thickness decreased, the Zackenberg glacier was confined in the interior of the main valley, leaving several lateral moraine ridges along the slopes. The deglaciation started by ~13.7-12.5 ka and accelerated paraglacial slope processes (e.g. solifluction). By ca. 10.5 ka, the last remnants of glacial ice disappeared from the lower sections of the valley. This deglaciation chronology broadly agrees with what is observed in other sites across Greenland.
Modelling the complex transient response of debris-covered glaciers to climate change and interaction with debris production
Authors: Ferguson James C. , Bolch Tobias , Banerjee Argha , Vieli Andreas
Published: March 2022

Numerical modelling studies examining the transient behaviour of debris-covered glaciers have typically varied either the equilibrium line altitude, which is a proxy for climate, or the rate of debris deposition. Since the rate of debris production from headwall erosion is believed to be an increasing function of temperature, a more faithful representation of debris-covered glacier evolution should include a coupling between debris source strength and climate.

In this study, we examine the transient response of debris-covered glaciers to the combined effect of a warming climate and a related increasing debris source using a numerical model that couples ice flow with englacially transported debris. This allows for a debris melt-out concentration in the ablation zone that varies in time and space, depending on the evolving glacier dynamics and the debris deposition history.

We find that debris-covered glaciers in a warming climate exhibit a complex transient response with aspects of both retreat and advance, though these distinct responses occur on different timescales. This suggests that the observed present-day retreat of debris-covered glaciers may be followed by an eventual advance despite a continued increase in global mean temperature.
Weather and climate in the AI-supported early warning system DAKI-FWS
Authors: Xoplaki Elena , Toreti Andrea , Ellsäßer Florian , Adakudlu Muralidhar , Hartmann Eva , Luther Niklas , Damster Johannes , Giebenhain Kim , Ceglar Andrej , Ma Jackie
Published: March 2022

The project DAKI-FWS (BMWi joint-project “Data and AI-supported early warning system to stabilise the German economy”; German: “Daten- und KI-gestütztes Frühwarnsystem zur Stabilisierung der deutschen Wirtschaft”) develops an early warning system (EWS) to strengthen economic resilience in Germany. The EWS enables better characterization of the development and course of pandemics or hazardous climate extreme events and can thus protect and support lives, jobs, land and infrastructures.

The weather and climate modules of the DAKI-FWS use state-of-the-art seasonal forecasts for Germany and apply innovative AI-approaches to prepare very high spatial resolution simulations. These are used for the climate-related practical applications of the project, such as pandemics or subtropical/tropical diseases, and contribute to the estimation of the outbreak and evolution of health crises. Further, the weather modules of the EWS objectively identify weather and climate extremes, such as heat waves, storms and droughts, as well as compound extremes from a large pool of key data sets. The innovative project work is complemented by the development and AI-enhancement of the European Flood Awareness System model, LISFLOOD, and forecasting system for Germany at very high spatial resolution. The model combined with the high-end output of the seasonal forecast prepares high-resolution, accurate flood risk assessment. The final output of the EWS and hazard maps not only support adaptation, but they also increase preparedness providing a time horizon of several months ahead, thus increasing the resilience of economic sectors to impacts of the ongoing anthropogenic climate change. The weather and climate modules of the EWS provide economic, political, and administrative decision-makers and the general public with evidence on the probability of occurrence, intensity and spatial and temporal extent of extreme events as well as with critical information during a disaster.
Assessment of the macroseismic/strong-ground motion distribution of the 2021 Crete (Arkalochori) earthquake sequence using a finite fault stochastic simulation approach
Authors: Ravnalis Michail , Kkallas Charalampos , Papazachos Constantinos , Papaioannou Christos
Published: March 2022

At 27/09/2021, 06:17 (UTC) a strong ground motion with moment magnitude M6.0 occurred on the island of Crete, approximately 25km SE of the city of Heraklion, near Arkalochori. The highest macroseismic intensity value was observed in the area of the central part of the peripheral unit of Heraklion (i.e., in the area of the Municipality of Minoa Pediada) and had a value of IMM = VII. The earthquake was also felt in the islands of the southern and eastern Aegean up to areas of Attica. We collected macroseismic data from EMSC considering a significant number of macroseismic testimonies and available strong motion information. The main goal was to perform a combined interpretation between observed and synthetic macroseismic data. In order to predict the expected ground motion measurements, for example peak ground acceleration (PGA) and peak ground velocity (PGV), as a function of distance and magnitude we used the stochastic simulation approach. These simulations are performed with the EXSIM code (Motazedian and Atkinson, 2005), as described by Boore (2009) taking into account finite-fault effects in ground-motion modeling. Good knowledge of the detailed rupture process is essential for realistic simulations of strong ground motion. Earthquake relocations for this aftershock sequence suffer from poor knowledge of the local velocity structure, especially for the shallow part of the crust. This was an important factor in the case of this earthquake, as the permanent network is rather sparse in this area. We employed a Monte Carlo parametric search of the velocity model space, realized through an adapted neighborhood algorithm, as included in the Geopsy software, together with a conventional location code. In this approach, the regional 1D velocity model, together with appropriate station corrections, is simultaneously estimated (non-linear optimization) with the relocation of the complete seismic sequence. Finally, a good agreement of the spatial distribution of the initial and modeled simulated macroseismic intensities is observed, showing that can reliably reconstruct the main features of the damage distribution approach for this earthquake.

 
Effect of spatially distributed radar-gauge rainfall products on simulated urban flows
Authors: Echeverri-Salazar Edwin , Shehu Bora , Verworn Alexander , Wallner Markus
Published: March 2022

Weather radars have become a valuable tool for urban hydrological studies because they capture the rainfall intensities at a high spatial and temporal resolution. However, radar products are affected by objects or phenomena not of meteorological interest, making it necessary to apply various algorithms to correct and improve their rainfall estimation. In addition, multiple methods for merging rain-gauge and radar data are presented in the literature, which combines the advantages of high spatial resolution of radar products with the measurement accuracy of rain gauge stations. While merging methods are commonly validated on rain-gauge measurements, little has been discussed in the literature about the influence of such techniques on urban hydrological models. Therefore, this study investigates the use and selection of gauge-radar merging methods as input for urban hydrological modeling.

This work studies the influence of different precipitation products (rain-gauge stations, radar, and radar-gauge merged products) on flow rates simulated with a hydrodynamic model in two cities: Hildesheim and Osnabrück, Germany. Sewer pipe measurements at least every 2 minutes for several discharge events within 2020-2021 are available and used to evaluate different rainfall products. The techniques to be assessed are temporal and spatial smoothing and radar merging methods such as external drift kriging, quantile mapping, and conditional merging. This study will allow identifying if, in general, there is a single product that presents the best results for urban flow simulations or if, on the contrary, it depends on the type of rainfall event. Additionally, since the study areas are located at different distances from the Hannover radar station, it will be possible to analyze the influence of the attenuation correction on the improvement of the radar product.
An advanced coupled modelling system to study interactions among the circulation, sea ice, and biogeochemistry in the Northwest Atlantic Ocean
Authors: Ohashi Kyoko , Laurent Arnaud , Renkl Christoph , Dilmahamod Fehmi , Yang Shengmu , Fennel Katja , Oliver Eric , Sheng Jinyu
Published: March 2022

The Northwest Atlantic (NWA) plays a critical role in the global ocean circulation and regulates the global climate system through meridional transport in western boundary currents as well as through deep convection. Global climate change is projected to significantly impact ocean circulation, vertical mixing, and sea ice dynamics in the NWA, with important implications for the area’s biological productivity and carbon export. These physical and biological features and their variabilities are challenging to numerical ocean models and often poorly represented in global climate models. This creates a difficulty in projecting future changes in nutrient dynamics, production, and carbon export. To address these challenges we have developed an advanced coupled circulation-sea ice-biogeochemistry modelling system for the NWA. This modelling system is based on the Regional Ocean Modeling System (ROMS), the Community Sea Ice Model (CICE), and a biogeochemical model including oxygen dynamics and carbon chemistry. The model domain spans the area from Cape Hatteras to Baffin Bay and from the east coast of North America to the central North Atlantic, with the horizontal grid resolution ranging from ~8 km in the south to ~2 km in the north. The circulation and sea ice models are forced by atmospheric and oceanic reanalysis data at the surface and lateral boundaries, respectively. The circulation model is additionally forced by tides, river discharge, and continental runoff. Preliminary model results are presented and compared to various types of observations, with a focus over coastal waters and the deep convection region of the Labrador Sea.
Spatial variability assessment of groundwater quality dispersion with reference to land-use indices
Authors: Tyagi Shipra , Sarma Kiranmay
Published: March 2022

The anthropogenic influences, allied with land-use dynamics, induce the spatial variability of the constituents by overall altering the groundwater qualitative status. It is one of the pertinent linkages, that is seldomly discussed, and in turn, would highlight an insight into the potent pollution sources, pathways, and emergent plumes for accretion or dilution effects in groundwater hydrochemistry. A case study was attempted for assessing the spatial variability of groundwater quality (within shallow aquifers) in the populous Ghaziabad district of western Uttar Pradesh of India. A total number of 26 sampling sites were analyzed for quality parameters such as major cations, anions, and heavy metals for pre-and post-monsoon seasons for two consecutive years (2017&2018). The magnitude of accretion and dilution effects in groundwater were estimated by using a numerical method of Normalized Difference Dispersal Index (NDDI), which targets the site-specific variability of the quality constituents in terms of degree and space. The index value for each constituent parameter was profiled by using geostatistical mapping (ordinary kriging) and further, validated for the spatial pattern through Global Moran’s I. For a plausible comparison, NDDI spatial maps were analyzed with land use indices, namely, Normalized Difference Vegetation Index (NDVI), Normalized Differential Salinity Index (NDSI), Normalized Difference Built-Up Index (NDBI), and Modified Normalized Difference Water Index (MNDWI), to predict the influence sources of accretion or dilution effects of the constituents in the groundwater quality. The obtained results have shown that the NDDI method coupled with land use indices, in the spatial extent, has profoundly estimated the plumes of abundant accretion/dilution of the quality parameters and hotspots were preferably found within the urbanized & highly populated as well as irrigating fields (peri-urban regions) of Ghaziabad district. The study concludes that spatial variations of groundwater quality are easy to comprehend and would pertinently assess the quality control while delivering groundwater monitoring & management strategies for predicting the impacts arising from land-use influences within the regional/localized studies.
Territorial analysis for energy supply of western Turin area from alternative renewable sources: impact and potential 
Authors: Paschetto Arianna , Caselle Chiara , Leso Claudia , Manfroni Fabrizio , Bonetto Sabrina Maria Rita
Published: March 2022

It is now generally assumed that a radical reversal in economy is needed in order to cope with the effects of climate changes and to improve the resilience of populations in relation to these effects.

In fact, European policies for climate change and economic recovery due to Covid-19 (Guidance to Member States, Recovery and Resilience Plans, 8th Environmental Action Program) are supposed to work in synergy to promote green and efficient energies, shifting the cost/benefit ratio in favor of renewable natural resources. As part of these policies, Italy is increasing the number of mini hydroelectric plants (max. power of 1000 kW), which are considered advantageous both in economic and environmental terms without being in contrast with the surrounding environment.

The aim of this study is the evaluation of potential production of hydroelectric energy, by means of mini hydroelectric, in the western area of ​​Turin, considering lowland areas (such as the Municipalities of Collegno, Druento and Alpignano) and high valley areas such as the Municipality of Coazze and upper Sangone Valley. In these investigated area, the development of mini hydroelectric could possibly result in partial or entire energy self-sufficiency.

In order to comply with environmental policies, a feasibility study will be conducted, based on geological, hydrogeological, morphological, ecological and climatic components.

The study will also be congruent with European and national guidelines regarding the Environmental Impact Assessment, so as to evaluate any possible plant locations in terms of environmental impact.

The geological and geomorphological data collected will also be employed to evaluate the possibility of reuse of the materials which could possibly accumulate in the reservoirs, in accordance with the policies of the Green Communities.
Societal responses to political and climatic changes in Babylon in the First Millennium BCE.
Authors: McGovern Rhonda , Kostick Dr. Conor , Hill Andrew , Medenieks Selga , Ludlow Dr. Francis
Published: March 2022

The Astronomical Diaries and Related Texts from Babylonia (Volumes I-III) provide sub-daily precisely dated meteorological observations recorded by ṭupšūtu (Akkadian for scribes) who were expert astronomers conducting a programme of observation spanning many centuries. Thanks to their use of clay as a medium, 209 (known) tablets survived, were excavated, translated and published, providing a unique window into the climate in the first millennium BCE.

A focus of the Irish Research Council-funded CLICAB Project (Climates of Conflict in Ancient Babylonia) is on deriving historic climate data from the translated tablets. Information has therefore been categorised into 50 unique keys, 24 of which refer to meteorological and related phenomena. This has facilitated the extraction of over 230,000 rows of observational data. Initial findings afford insight into the impact that ruling elites (and changes in governing regimes) had on the recording of observations, and therefore the availability of data with which to analyse past climate; but also on how mitigation strategies were implemented to improve (not always successfully) daily life.  

For the Ancient Babylonians the ruling elite (of Babylonia or neighbouring regions) could act as a key facilitator in promoting socio-economic viability in an often challenging environment through for example, the division of land for food production, as noted in the diary which remarked that fields were given “in year 32 at the command of the king for sustenance for the people of Babylon” (April 273 BCE). 

However the monarch could also act as an obstacle to societal environmental resilience. An example presented in the diaries highlights the use of water as a tool of conflict in an attempt to take over the kingdom (119 BCE). The diaries record Euphrates River level heights which may provide a longer time series than is available for the contemporary period due to ongoing and contentious hydro-politics in the region today (Travis et al., forthcoming; Kirschner & Tiroch, 2012).

There is also abundant evidence of the climatic impacts from major explosive eruptions in the diaries, the dating of which is now known thanks to recently revised ice-core chronologies (Sigl. et al., 2015), e.g. “the cold became severe” from the 8th-15th January 247 BCE. The combination of precisely dated meteorological information and river levels, alongside evidence of volcanic induced perturbations, and historical or “event” data are a distinctive characteristic of the diaries. This combination enables a deeper understanding into societies of the First Millennium BCE and their adaptive capacity when faced with changing political regimes and climates.  
The global dataset of Phanerozoic glendonites and paleogeographic reconstructions 
Authors: Ershova Victoria , Rogov Mikhail , Gaina Carmen , Vereshchagin Oleg , Vasileva Kseniia , Mikhailova Kseniia , Krylov Aleksei
Published: March 2022

Glendonites are carbonate (mainly calcite) pseudomorphs after metastable ikaite (CaCO3·6H2O); Glendonites have been found worldwide in Paleoproterozoic to Quaternary sediments.  Modern ikaite are mostly found in regions that experienced low temperatures, thus glendonites are considered to be an indicator of near-freezing temperatures in the past (e.g. Kaplan, 1978; Shearman and Smith, 1985; Last et al., 2013). Indeed, glendonites have been found in association with glaciomarine sediments (Johnston, 1995; James et al., 2005; Thomas et al., 2005; Spielhagen and Tripati, 2009), and they have also been associated with upwelling of near-freezing waters onto relatively shallow shelves (Brandley and Krause, 1994; Jones et al., 2006, Mikhailova et al, 2019). Despite the general association with cold conditions, the relevance of glendonites as a paleotemperature indicator is still questioned (Shearman and Smith, 1985; Teichert and Luppold, 2013). To test the geographical distribution of glendonites through time, and attempt an understanding of the paleoenvironment that facilitated their occurrences we have compiled a global database of Phanerozoic glendonites (Rogov et al., 2021).  This dataset has been reconstructed for key Mesozoic and Palaeozoic time intervals by using a global kinematic model. Our reconstructions indicate that most glendonites occurrences in Mesozoic and Palaeozoic times were originally formed in the polar or close to polar regions. The Cenozoic and especially recent glendonites formed close to polar seas (mainly Arctic wide shelves) or on deep-water continental margins (ex.  Zaire deep fan, Nankai Trough, Sakhalin Island slope). The preservation potential of deep-water sediments in geological record are lower than epicontinental and marginal seas. Based on our global Phanerozoic reconstructions we suggest that documented glendonites found in Phanerozoic deposits could be used as a paleoclimatic indicators of cold-water environments. 
Understanding and reducing surface biases over the Southern Ocean in the FOCI climate model
Authors: Kjellsson Joakim , Wahl Sebastian , Martin Torge , Park Wonsun
Published: March 2022

We examine the current surface biases in sea-surface temperature (SST), sea-ice fraction, and winds over the Southern Ocean in the FOCI climate model and demonstrate various methods to reduce them. We examine and tune biases in both atmosphere-only simulations with ECHAM6 and OpenIFS 43r3 and coupled models FOCI (ECHAM6+NEMO) and FOCI-OpenIFS (OpenIFS + NEMO). Over the Southern Ocean both coupled climate models suffer from a warm SST bias, low sea-ice fraction, and surface westerlies with a maximum too far north. We explore how modifying ocean mixing parameters, air-sea coupling frequency and ice model parameters impacts surface biases. 

Shortening coupling frequency in the FOCI model from 3-hourly to hourly reduces both the warm SST bias and the low sea-ice fraction bias, while the northward bias of the westerly wind maximum is largely unchanged. This suggests that the SST and sea-ice fraction biases are related to a lack of wind gustiness and not the biases in mean the winds. Similarly, reducing the horizontal tracer diffusion in the ocean from 600 m2/s to 300 m2/s also reduces the warm SST bias and the low sea-ice fraction bias. The cooling of the Southern Ocean surface is likely due to a reduced vertical heat transport by the tracer diffusion, which is along iso-neutral surfaces. Combined, both reducing the coupling frequency and re-tuning the horizontal mixing parameters acts to reduce the Southern Ocean surface biases more than either one alone. 

The two coupled models, FOCI and FOCI-OpenIFS, share identical ocean model configurations, NEMO ORCA05, but produces warm SST biases in different ways. OpenIFS suffers from a strong cloud radiative forcing bias which is not existent in ECHAM. Hence, reducing the SST and sea-ice fraction biases in FOCI-OpenIFS requires improvements in the cloud scheme rather than tuning oceanic mixing parameters. 