bluuebunny/crossref_metadata_2025 huggingface dataset:
Nearly instantaneous probabilistic retrievals of Rain over Africa
Authors: Amell Adrià , Eriksson Patrick , Hee Lilian , Pfreundschuh Simon
Published: February 2023

How much has rained in the last minutes anywhere in Africa? Contrary to Europe or North America, a dense network of weather radars providing this information is not available on the African continent. A new product, Rain over Africa, aims to find an answer to the question by retrieving rain rates from Meteosat geostationary infrared images and making them available to the public within minutes from satellite downlink. By using geostationary observations, rain retrievals with a resolution of 3-5 km and 15 min update time can be offered.
Machine learning is at the core of Rain over Africa. The GPM DPR and GMI combined precipitation L2B product was exploited to train a convolutional neural network. The trained model outputs a pixel-wise rain rate distribution free from traditional assumptions, enabling not only point estimates such as an expected value, but also non-Gaussian error estimates or likelihoods of extreme events by computing tail probabilities. Moreover, the Rain over Africa retrievals compare similar to the IMERG Late Run product, but can offer additional statistics at a finer spatiotemporal resolution, with a product latency of few minutes instead of hours.
Further details on the model and its performance, characteristics of the Rain over Africa product, how to access the data, and data availability, combined with a product outlook, will be given in this presentation.
DeepRain: a separable residual convolutional neural algorithm with squeeze-excitation blocks for rainfall nowcasting
Authors: Abdelhalim Ahmed , Rico-Ramirez Miguel , Han Dawei
Published: February 2023

Precipitation nowcasting is critical for mitigating the natural disasters caused by severe weather events. State-of-the-art operational nowcasting methods are radar extrapolation techniques that calculate the motion field from sequential radar images and advect the precipitation field into the future. However, these methods assume the motion field's invariance, and prediction is based solely on recent observations, rather than historical radar sequences. To overcome these limitations, deep learning methods such as convolutional neural networks have recently been applied in radar rainfall nowcasting. Although, the promising progress of using deep learning techniques in rainfall nowcasting, these methods face some challenges. These challenges include producing blurry predictions, inaccurate forecasting of high rainfall intensities and degradation of the prediction accuracy with rising lead times. Therefore, the aim of this study is to develop a more performant deep-learning model capable of overcoming these challenges and preventing information loss in order to produce more accurate nowcasts. DeepRain is a convolutional neural network that uses a spatial and channel Squeeze & Excitation Block after each convolutional layer, local importance-based pooling, and residual connections to improve model performance. The algorithm is trained and validated using the UK Met Office's radar rainfall mosaic, which is produced by the UK Met Office Nimrod system. Using verification metrics, the model's predictive skill is compared to another deep learning model and a range of extrapolation methods.Keywords: deep learning; rainfall nowcasting; radar; convolutional neural networks; Squeeze-and-Excitation
z-coordinates with surface layer insertion/removal for accurate representation of free-surface flows in ocean models
Authors: Arpaia Luca , Ferrarin Christian , Bajo Marco , Umgiesser Georg
Published: February 2023

Ocean model performances are highly related to the vertical coordinate system implemented. We study geo-potential (or z-) coordinates and we focus on the numerical treatment of the moving free surface. Typically z-coordinate models are coded with a surface layer with varying but not-vanishing thickness, which limits the vertical resolution in areas with high tidal range. We propose a z-coordinate algorithm that, thanks to the insertion and removal of surface layers, can deal with an arbitrary large tidal oscillation independently of the vertical resolution. The algorithm is based on a classical two steps procedure used in numerical simulations with moving boundaries (grid movement followed by a grid topology change) which leads to a stable and accurate numerical discretization. With ad-hoc treatment of advection terms at non-conformal edges that may appear due to insertion/removal operations, mass conservation and tracer constancy are preserved. This algorithm can be reverted, in the particular case when all layers are moving, to other surface-following z-coordinates, such as z-star. With a simple truncation error analysis and realistic numerical experiments, we show the performances of z-coordinates with surface layer insertion/removal in coastal environments.
Biostimulant applications to mitigate multiple summer stress effects on potted Corylus avellana L. young plants
Authors: Vanacore Lucia , Modarelli Giuseppe Carlo , El-Nakhel Christophe , Pannico Antonio , Rouphael Youssef , Cirillo Chiara
Published: February 2023

In the current scenario of decreasing in precipitation and water resources, and increasing in temperature,   it is pivotal to define multiple strategies to cope with the negative consequences on the crop production and food security. Hazelnut (Corylus avellana L.) is an important nut tree crop grown in several countries all over the world and mainly in the Mediterranean Basin area. Among the producer countries Italy is the second main worldwide producer, soon after Turkey. Despite the long-lasting and traditional cultivation of hazelnut in the hilly areas and a recent wider spread of its orchards to newly cultivated fertile plains, hazelnut is well known as a very sensitive species to both water stress and high temperatures. The main aim of this study was to evaluate growth performances and morpho-physiological adaptive responses to prolonged water stress in potted young hazelnut plants. Secondarily, the effect of biostimulant treatments in mitigating the effects of water and heat stresses were evaluated. The research was conducted on one-year-old cultivar micro propagated plants of cv “Tonda di Giffoni” grown in a cold polycarbonate greenhouse at the Department of Agricultural Sciences of the University of Naples “Federico II” during two consecutive growing seasons. Three irrigation levels (i.e. 100, 80, and 60% of the daily water requirement) were applied in combination with two different biostimulant treatments. In particular, they consisted in the application near the roots of protein hydrolysate or mycorrhizae inoculation. The first one was applied every two weeks with a dosage of 2.5 ml/l according to the chemical characteristics of the product, during the whole growing season; instead, the second one was applied with a single-dose of 15 g per plant at the beginning of each growing season. During the two seasons, growth rate (i.e. basal diameter, branch length, leaf number, leaf area, and buds), eco-physiological behaviour (i.e. gas exchanges measurements, Chlorophyll a fluorescence emission, SPAD index, and leaf water potential), and leaf functional traits were investigated. Results   showed that the use of biostimulant and mycorrhizae positively influenced physiological behaviour and growth of plants by counteracting deficit irrigation stress effects. In conclusion, our study demonstrate how these type of treatments help to improve the quality of plants.
Paleoprecipitations recorded by rock magnetic properties of stalagmites from the Gruta da Ceramica, Portugal
Authors: Brás Ana Raquel , Font Eric , Reboleira Ana Sofia , Melo Rui , E. Spangenberg Jorge , Fonseca Paulo
Published: February 2023

Speleothems are potential candidates for paleomagnetic and paleoclimatic reconstructions. Recent studies suggest that the abundance of magnetic minerals trapped in the calcite laminae of stalagmites is controlled by paleoclimatic and paleoenvironmental parameters including precipitation, vegetation and soil erosion. Here we test this hypothesis by studying speleothems from the Cerâmica cave in Penela, Portugal. We conducted carbon and oxygen isotopic analysis, together with the measurement of concentration-dependent magnetic proxies, including natural remanent magnetization, anhysteretic remanent magnetization, isothermal remanent magnetization and mass specific magnetic susceptibility. Results show a moderate but significant correlation between carbon and oxygen isotopic composition and the content in magnetite. An increase in magnetite content is correlated to increased precipitation and increased contribution of organic material. These results corroborate previous observations that rock magnetic properties of speleothems can provide useful information for paleoclimate reconstructions. Acknowledgments: this work was funded by the Foundation of Sciences and Technology of Portugal (refs. PTDC/CTA-GEO/0125/2021; MIT-EXPL/ACC/0023/2021) and IDL (ref. FCT/UIDB/50019/2020).    
Compositional diversity of the Europa-Ganymede plasma environment
Authors: Szalay Jamey , Bagenal Fran , Allegrini Frederic , Bolton Scott , Ebert Robert , McComas David , Sarkango Yash , Valek Philip , Wilson Robert
Published: February 2023

Jupiter’s plasma sheet is understood to be dominated by Io-genic material, mostly in various charge states of sulfur and oxygen. This material moves radially away from Jupiter, filling its magnetosphere. The material in the plasma sheet interacts with Europa and Ganymede, which are also sources of magnetospheric pickup ions, mostly in the form of both atomic and molecular hydrogen and oxygen. Juno’s plasma instrument JADE, the Jovian Auroral Distributions Experiment, has provided the first comprehensive in-situ observations of the composition of Jupiter’s plasma sheet with its Time-of-Flight mass-spectrometry capabilities. Here, we present observations of the magnetospheric composition in the Europa-Ganymede region of Jupiter’s magnetosphere. We highlight how Europa-genic material is often present and at times can be the dominant population for certain atomic masses, revealing a more complex and compositionally diverse magnetosphere than previously thought.
CHAPS: A New, Compact Hyperspectral Imager for Air Pollution Remote Sensing
Authors: Swartz William , Krotkov Nickolay , Lamsal Lok , Morgan Frank , Stewart Benjamin , Zimbeck Walter , Otter Gerard , Kempen Floris van , Levelt Pieternel , Veefkind Pepijn
Published: February 2023

Current and planned low Earth orbit and geostationary satellite instruments have long provided global surveys, revealing air pollution characteristics and trends. Targeted pollution observations with even finer spatial and temporal resolution would better characterize, quantify, and monitor emissions from urban areas, power plants, and other anthropogenic activities, with both scientific and societal benefits. The Compact Hyperspectral Air Pollution Sensor (CHAPS) is an imaging spectrometer in a CubeSat form factor, made possible by the use of freeform optics and additive manufacturing. CHAPS has the potential to complement global surveyors and provide targeted observations valuable for understanding air quality at urban scales. The instrument is designed to make measurements of atmospheric composition at 300–500 nm (@ 0.6-nm spectral resolution) at unprecedented spatial resolution from low Earth orbit (1 x 1 km2). The NASA Earth Science Technology Office has funded the development of a CHAPS–Demonstrator (CHAPS-D), which will result in an airborne demonstration of a CHAPS prototype instrument. The CHAPS-D project is a joint collaboration of JHU/APL (USA) and TNO (The Netherlands). CHAPS-D freeform optics derive heritage from the Sentinel-5 Precursor (TROPOMI) mission. Freeform optics has potentially huge advantages over traditional optical designs, including fewer optical surfaces and lower mass and volume, while maintaining optical performance, and CHAPS-D will fit within the design constraints of a 6U CubeSat. The CHAPS-D mechanical structure and some optical elements will be fabricated using additive manufacturing, using a next-generation aluminum alloy. This approach simplifies the construction of the instrument and allows for integral stray light baffling features not possible using traditional fabrication approaches. The compact size and relatively lower cost of CHAPS makes a constellation feasible for the first time, with unprecedented spatiotemporal sampling of global point pollution sources. The project will culminate in an airborne demonstration of CHAPS-D, with 30-m spatial resolution. We will retrieve NO2, SO2, HCHO, ozone, and other trace species relevant to air quality from solar backscatter measurements. We present the science context, measurement requirements, and preliminary design of CHAPS-D, as well as results from breadboard testing.
Quantifying water use resilience from sap flow data to better understand post-drought effects on tree functioning
Authors: Poyatos Rafael , Fatecha Brenda , Nelson Jacob A. , Flo Víctor , Granda Víctor , De Cáceres Miquel , Anderegg William R.L. , Bittencourt Paulo R.L. , Fisher Rosie A. , Junttila Samuli , Konings Alexandra , Migliavacca Mirco , Miralles Diego G. , Novick Kimberly A. , Rowland Lucy , Zhang Weijie , Mencuccini Maurizio , Martínez-Vilalta Jordi
Published: February 2023

Drought impacts on vegetation function have been widely assessed globally but our understanding of the global patterns of drought recovery and its mechanistic underpinnings is comparatively less understood. The quantification of vegetation resilience to drought has been mostly based on the analysis of time series of remotely-sensed vegetation indices, tree-ring data or ecosystem-level fluxes. While useful, these approaches have not provided a mechanistic link between resilience patterns and post-drought effects on plant hydraulics because they lack sufficient temporal and spatial resolution. Resilience quantified from tree-level sap flow can provide these mechanistic insights on post-drought effects but its estimation using classical resilience metrics requires defining a reference sap flow, unaffected by drought. Here, we compare two different approaches to estimate tree water use resilience to soil drought for >500 drought events using global, tree-level sap flow data in the SAPFLUXNET database (Poyatos et al. 2021). For both approaches, soil droughts were defined using the same criteria based on soil relative extractable water (REW), ensuring a minimum intensity and duration (10 days) and the presence of well-defined pre- and post-drought periods with REW values sustainedly above the threshold. In the first approach, we apply classical resilience metrics obtained from the comparison of pre- and post-drought sap flow. We show that water use resilience is related to soil drought characteristics such as intensity and duration and also to atmospheric vapour pressure deficit. In the second approach, we present a model-based resilience framework in which actual sap flow during and after a drought is compared against a reference sap flow modelled using a random forest regression with hydrometeorological drivers, but excluding potential drought legacy effects. This latter approach is tested in two Mediterranean forests in SAPFLUXNET where additional data on tree water status (leaf water potentials or tree water deficit derived from automatic dendrometry) are also available. We show that the model-based resilience framework applied to sap flow data is a promising avenue to better understand the global patterns of drought recovery and the underlying hydraulic mechanisms.Poyatos, R. et al.: Global transpiration data from sap flow measurements: the SAPFLUXNET database, Earth System Science Data, 13, 2607–2649, https://doi.org/10.5194/essd-13-2607-2021, 2021. 
Passive seismic and infrasonic monitoring at the Mefite d’Ansanto deep-CO2 degassing site (Southern Apennines, Italy).
Authors: Valoroso Luisa , Cianetti Spina , De Gori Pasquale , Diaferia Giovanni , Giunchi Carlo , Improta Luigi , Piccinini Davide , Zuccarello Luciano , Cogliano Rocco , Fodarella Antonio , Minichiello Felice , Pucillo Stefania , Di Luccio Francesca
Published: February 2023

The role of fluids in the preparatory phase of major earthquakes and in the evolution of aftershocks and swarms in space and time is well-documented. In particular, numerous studies evidence the primary role that mantle-derived fluids play in the generation of large upper crustal earthquakes in extensional domains, where crustal-scale faults act as preferential hydraulic pathways.  We focus on the Mefite D'Ansanto degassing site, the largest low-temperature non-volcanic CO2 emission in the world, located at the northern tip of the Mw6.9 1980 Irpinia faults. The study area experienced strong historical earthquakes (1702, 1732 and 1930 M6+ earthquakes) but it is characterized by a relatively low background seismicity rate with respect to the nearby Sannio and Irpinia regions.    To collect high-quality microseismicity data in this key sector of the southern Apennine extensional belt and investigate the relationship among seismicity, crustal fluids, and physical-hydraulic properties of the crust, we installed in July 2021 (up to May 2023) a temporary network composed of 10 stations equipped with short-period velocimeters (5 sec). The temporary network covers an area of approximately 30x30 km2 surrounding the Mefite d’Ansanto site and integrates with the numerous permanent stations of the INGV and ISNet networks located at the boundary of the survey area. Within the Mefite area, we also deployed a temporary seismo-acoustic dense array to study two CO2 vents. The seismo-acoustic array is composed of 5 infrasonic stations equipped with IST-2018 broadband microphones developed by The ISTerre (Université Savoie Mont Blanc, France), in addition to one seismo-acoustic station equipped with a co-located digital broadband seismometers (120s). The array is positioned approximately at the vertices of a star, with an aperture of about 50 meters. The deployment lasted for 1 week at the end of May 2022, allowing us to sample the emission site during “dry” weather conditions. We show first results of the analysis of seismicity recorded by the temporary network applying both standard (STA/LTA) detection algorithms or innovative enhanced techniques such as cross-correlation based template-matching algorithms and/or Deep-Learning-Phase-Recognition methods.The activities are developed in the framework of the multidisciplinary project FURTHER (https://progetti.ingv.it/en/further).
Constraining spatio-temporal variations in dust emission at global scale with ensemble data assimilation of satellite optical depth retrievals
Authors: Escribano Jerónimo , Di Tomaso Enza , Jorba Oriol , Gonçalves Ageitos María , Klose Martina , Basart Sara , Pérez García-Pando Carlos
Published: February 2023

Mineral dust emissions play a fundamental role in the simulation of the dust cycle in numerical models. The emission of dust depends on a number of atmospheric and surface conditions that span a large range of time and spatial scales. Due to the inherent difficulties to physically represent this complexity in a simplified way, the emission of mineral dust is usually parameterized in the atmospheric numerical models. The heterogeneity of available dust emission parametrizations, along with the soil characteristics and meteorological information, the atmospheric models themselves, their tuning, and their boundary and initial conditions, contribute to the large spread of net dust flux estimated with different modeling frameworks.This work presents a novel approach to estimate dust emissions through the assimilation of dust optical depth filtered retrievals from satellite measurements, by means of an ensemble-based data assimilation scheme. Because of the lagged nature of the emission inversion problem, the assimilation is produced with a slightly modified version of the ensemble Kalman Filter algorithm. We show results of the inversion for 5-year global numerical experiments (2017 to 2021), by using dust-only simulations with three of the available state-of-the-art dust emission schemes implemented in the chemical MONARCH model.In these three experiments, we assimilate dust optical depth obtained from the SNPP-VIIRS Deep Blue retrievals. The control vector consists of model dust emissions at native spatial resolution (1.4 by 1 degrees) and a 3-days time resolution. We find regional and temporal corrections in the estimated emissions after assimilation that are consistent across the different dust emission scheme experiments, making our findings robust. We compare the dust optical depth of our simulations with the assimilated observations, as well as with independent dust-filtered optical depth from ground-based AERONET sun-photometers. The dust optical depth resulting from the simulations that use the corrected emissions show substantial improvements in the skill scores than the dust optical depth simulated with the uncorrected emissions. Our work paves the road toward quantifying and eventually reducing uncertainties in dust emission schemes and toward better constraining the contribution to climate of the dust sources at sub-regional scale.
The influence of climate forcings on global glacier evolution over the last millennium
Authors: Vlug Anouk , Marzeion Ben , Prange Matthias , van der Laan Larissa , Maussion Fabien
Published: February 2023

Glacier evolution over the past century is, in part, caused by prior changes in the climate, resulting from both internal variability in the climate system and changes in external forcings. Therefore, the focus in this study is on the last millennium, to gain more insight into the build-up of the little ice age and the following glacier retreat. The role of the individual climate forcings (volcanic, greenhouse gasses (GHG), orbital, land cover and land use change (LULCC), solar and anthropogenically induced ozone and aerosols) is addressed through simulations with the Open Global Glacier Model (OGGM), using climate time series from the Community Earth System Model Last Millennium Ensemble (CESM-LME) as forcing. Our study is novel in both experimental set-up and in that it is the first global glacier attribution study on this time scale, simulating more than a small selection of glaciers.How a glacier evolves is dependent on the state the glacier is in and on the climate. We take both these aspects into consideration in our global glacier last millennium attribution study. Instead of letting the glaciers freely evolve in the attribution experiments, we prescribe the glacier geometry based on a factual case, in order to avoid mass change being attributed based on the wrong glacier state (e.g. a glacier that has disappeared instead of an existing glacier). To create a factual case, the Last Millennium Re-analysis (LMR) is used as forcing in OGGM. This has the additional benefit that it gives the opportunity to address spin-up issues, as the LMR starts in 0 CE and the CESM-LME 850 years later.Finally, the preliminary results show that changes in the volcanic forcing had a relatively minor role on the long term global glacier evolution over the last millennium. Instead LULCC and orbital forcing seem to have had a significant influence leading up to the little ice age maximum extent, and the GHG to the recent glacier retreat. Without anthropogenic forcing the glaciers would still be growing instead of retreating, as a result of GHG emissions.
Flare-accelerated electrons and their traces in the solar corona observed by space- and ground-based instruments
Authors: Bröse Malte , Vocks Christian
Published: February 2023

A joint analysis approach is used to study flare signatures both in the low and higher corona. STIX, AIA and LOFAR data provide an extensive picture about different aspects of flare characteristics. Recent data by the STIX instrument complement the picture of accelerated electrons, which propagate along magnetic field lines towards the Sun. These observations are linked to the LOFAR data, which contain information about the elctrons propagating away from the Sun through the corona above the active region. Although, the active region and its thermal evolution (Differential Emission Measure (DEM) reconstruction of AIA data), flare accelerated electrons and their radio traces (LOFAR, STIX) are in principal all associated with the energy release during the flare process, they are often studied seperatly. Hence, the investigation of possible relations is part of this project. Solar magnetic fields as a binding element between low and high corona, accelerated electrons and heated flare loops are included in the analysis via a Potential Field Source Surface (PFSS) model.
A Subgrid-scale Model for Energy Buildup in the Solar Corona
Authors: Antiochos Spiro , Dahlin Joel , DeVore C. Richard
Published: February 2023

The solar corona routinely exhibits explosive activity, in particular coronal mass ejections and their accompanying eruptive flares, which have global-scale consequences. These events and their smaller counterparts, coronal jets, originate in narrow filament channels. The key processes that form and evolve the channels operate on still smaller spatial scales and much longer timescales, culminating in a vast separation of characteristic lengths and times that govern these explosive phenomena. We describe implementation of an efficient subgrid-scale model for generating eruptive structures in magnetohydrodynamics (MHD) coronal simulations. STITCH-STatistical InjecTion of Condensed Helicity-is a physics-based, reduced representation of helicity condensation: a process wherein small-scale vortical surface convection forms ubiquitous current sheets and pervasive reconnection across the sheets mediates an inverse cascade of magnetic helicity and free energy, thereby forming the filament channels. We have developed a formalism, STITCH, that abstracts these complex processes into a single term in Ohm's law and the induction equation that directly injects tangential magnetic flux into the low corona. We show that our approach is in very good agreement with a full helicity condensation calculation that treats all of the dynamics explicitly, while enabling substantial reductions in temporal duration and spatial resolution. We illustrate the flexibility of STITCH at forming localized filament channels and at energizing complex surface flux distributions that have sinuous boundaries. STITCH is simple to implement and computationally efficient, making it a powerful technique for physics-based modeling of solar eruptive events. 

This work was funded by the NASA LWS and ISFM Programs.
Linking soil microbial carbon sequestration to cover crop diversification in agricultural soil systems across Europe
Authors: König Alexander , Rosinger Christoph , Keiblinger Katharina , Zechmeister-Boltenstern Sophie , Herrmann Anke , Inselsbacher Erich
Published: February 2023

Sequestering atmospheric CO2 into soil organic matter through changes in agricultural practices is an appealing idea to improve soil ecosystem services and to improve global change mitigations. The old view of carbon (C) stability in soil, based on the intrinsic properties of the organic matter inputs (e.g. lignin content), would lead policy towards greater percentages of recalcitrant organic matter content in crops. Recent research suggests otherwise and that managing how the soil microbiome process C inputs is a more fruitful approach (Sokol et al., 2019, Poeplau et al., 2019). It is therefore to decipher and evaluate the link between the aboveground plant community and the complex belowground diversity of the microbiome and their metabolic processes that mediate C sequestration. Lehmann et al. (2020) proposed a theoretical framework in which the persistence of C in soil can be understood as the outcome of interactions between the molecular variability of organic matter input and spatio-temporal microbial heterogeneities of the soil system.Within the EnergyLink framework we therefore investigate various microbial markers to illuminate possible physiological changes across several European agricultural field sites with different cover crop management types. Specifically, for detecting shifts in microbial necromass composition and quantity we target amino-sugars (galactosamin, gluctosamine, mannosamine and muramic acid), for evaluating effects on growth rates we measure 14C incorporation into ergosterol for fungi and 14C-leucine incorporation for bacteria and to grasp changes in uptake strategies we test extra cellular enzyme activities for different nutrient classes. Additionally, we determine C:N:P ratio for bulk soil, microbial biomass and above ground plant biomass to estimate stoichiometric imbalances. Here we present results from our first sampling campaign and discuss implications of diversified cover crops on soil carbon properties on a European scale.
Exploring the Impact of a Southern Ocean Anticyclonic Eddy on Biogeochemical Structure Using BGC-Argo Float Observations
Authors: Guisewhite Nicola , Chambers Don , Tamsitt Veronica , Williams Nancy
Published: February 2023

Recent studies have found that eddies in the Southern Ocean can contribute to both uptake and outgassing of CO2, emphasizing a need to understand the impact of eddies on biogeochemical structure in the Southern Ocean.  Despite having a significant role in climate regulation and global ocean transport, the Southern Ocean and its eddies are largely under-sampled, leaving many unknowns when trying to understand how the Southern Ocean can be impacted by a changing climate.  Whereas CO2 and other biogeochemical properties including oxygen and nitrate (which can be studied as indicators of a changing climate) are historically under-sampled and understudied in the Southern Ocean, the use of autonomous vehicles has allowed for the collection of high-quality data that can be used to analyze the impact of eddies on Southern Ocean biogeochemical structure.  A SOCCOM BGC-Argo Float encountered and sampled an anticyclonic eddy in the area lying between 54° and 50° S and 148° and 143° W in February 2019.  During the encounter, the float collected daily profiles of the biogeochemical structure within the eddy.  Using additional resources for sea surface height, wind, and ocean currents, we conduct a spatial and temporal analysis of the biogeochemical structure of the eddy.  We compare float data to climatologies, examine the physical properties that impact the mixed layer depth within and around the eddy, and understand how these properties influence biogeochemical variability caused by the eddy.  In addition, we pull biogeochemical data from all known eddy encounters by SOCCOM BGC-Argo floats and determine the significance of eddies on biogeochemical structure in the Southern Ocean.
A new 3D multicomponent markov chain model incorporating multi-scale soil structure with microbial distribution
Authors: Wu Kejian
Published: February 2023

One of the main challenges in soil science lies in the passage from heterogeneous soil structure to a quantified multi-scale 3D model. Here a new approach to quantify the microbial distribution relating to soil pore structure is presented. Characterising 3D microbial soil structural in digital porous media is not found and most soil process models tend to assume a homogenous spatial distribution of microbes. We measured the in situ spatial distribution of bacteria in arable soils across scales from sub-micrometers to metres and here we describe further progress to quantify and explicitly model the 3D microbial distributions, based on a stochastic Bayesian approach to predict spatial variation in the underlying bacterial intensity measure. A 3D higher order Multi-Markov chain model is introduced to model complex geometry of real soil structure and associated microbial distribution. In this study, Markov random fields are used to construct multiscale 3D Pore Architecture Models (PAM). The binary structure of PAM has been successfully used to predict multiphase flow behaviour in porous media such as hydrocarbon bearing reservoir rocks, we explore further to use such a new multi-components scheme in modelling pore structure incorporating with microbial spatial distribution, the multicomponent Markov chain model, which is a stationary multiple higher order Markov chain. The models parameterisation is based on high resolution SEM images of soil that have been prepared in a manner that preserves the microbial community information in situ. Based on the quantified 3D multiscale soil structure associated with microbial distribution components, the accurate reactive flow of microbial degradation can be simulated to predict environmental impact of microbial activates in the field. A variety of examples of structures and bacterial distribution created by the models are presented.
Quantification of the land-use pattern and areal effects of the hydropower development in Norway
Authors: Kenawi Mahmoud
Published: February 2023

Renewable energy sources are being increasingly utilized in order to mitigate climate change and phase out the use of fossil-based fuels. However, the impact of developing such energy sources on the land and ecosystem needs to be assessed and mitigated properly to avoid any source of problem shifting.Hydropower is considered nationally and globally the dominant source of renewable energy that can effectively contribute to reducing the usage of fossil fuels as well as being a backbone to help other renewable energy sources with their problem of variability due to its flexibility of production. However, the alteration of the land dynamics due to its deployment varies significantly depending on various spatial and technological factors.In Norway, more than 70% of hydropower production was developed in the period between 1950 and 1980.  yet, the identification of the land system used for this development and the alteration of the landscape remains unknown.This work contributes to the limited insights of quantifying the land used for hydropower development in Norway and how the land has transformed due to this development over time. We classified historical aerial images representing the areas for 40 hydropower systems in Norway counting for 8.1 GWh installed capacity which is 24% of Norway’s total hydropower installed capacity and 12% of the total reservoir area. We analyzed what kind of land was used for this development and compared these historical images with recent images to assess the land use change surrounding these hydropower systems with a 1 km buffer zone.  We found that 63% of the total reservoir areas were already existing water bodies while 9% of the vegetation land was used for this development. We also found that 84% of the reservoirs were built on existing lakes or lakes that were expanded due to hydropower developments. Additionally, we found that vegetation percentage either remained still or continued growth in most of the analyzed schemes while urban development was slightly small counting only for scattered cabins deployment and construction of roads.  The results of this work help unveil the uncertainties between land dynamics and hydropower development in Norway.  
Natural ventilation through open bedrock fracture systems and its influence on rock slope stability
Authors: Scheiber Thomas , Snook Paula , Haanes Hallvard , Maschler Alexander , Schild Lukas
Published: February 2023

Open bedrock fracture networks are characteristic structural features in unstable rock slopes. They affect the subsurface bedrock temperature field due to fracture ventilation and temporary water infiltration. The ground thermal conditions are a key factor influencing slope stability. Ascending air circulating through fracture networks during winter (the so-called chimney effect) facilitates the cooling of the ground and leads in some cases to the development of extra-zonal permafrost. In addition, fracture networks exposed to the atmosphere have an impact on gas exchange processes at the Earth-atmosphere interface. Natural ventilation of the underground compartments can thus lead to increased gas exhalation to the surface. Especially the radioactive gas radon (222Rn) has been used in Earth science and environmental studies of natural ventilation systems and has due to its relatively long half-life great potential to characterize the subsurface bedrock fracture systems.We present a case study of a natural ventilation system from the Stampa rock slope instability (Aurland, Norway). The area above the slide scar is characterized by a relatively low slope angle and bedrock lineaments, which correspond to morphological depressions and open subsurface fractures. Natural ventilation through these fractures has been observed at several locations at Stampa, where air flows out or in. Such chimney ventilation depends upon outside air temperature compared to subsurface temperature but also on locality and other atmospheric conditions such as wind and air pressure. Rock-surface and air temperature loggers in open fracture systems can provide information about both subaerial temperature and the subsurface temperature field, which can be use to model the chinmey ventilation. Instruments continuously monitoring air flow and radon concentration at selected vents, in addition to sporadic alpha track radon surveys are used to identify the extent and connectivity beween individual ventilation systems and verify ventilation patterns. In situ measurements are combined with UAV surveys using both optical and thermal imaging. We found that air ventilation through several individual systems of open bedrock fractures leads to cooling of the ground and to the development of sporadic extrazonal permafrost far below the regional permafrost limit. Radon concentration of outflowing air is depending on the air flow rate and the rock-atmosphere contact area which, in turn, depends on ground water level and the extent of ice in subsurface fractures. The subsurface bedrock reaches its highest temperatures in late autumn/early winter which coincides with enhanced slope deformation. 
Increasing the sampling density of 3D GPR data using multiple-point geostatistics
Authors: Irving James , Zhang Chongmin , Gravey Mathieu , Mariéthoz Grégoire
Published: February 2023

3D GPR data, where measurements are acquired along a series of parallel survey lines, offer much potential for gaining important information about complex subsurface environments. Such data are, however, extremely time consuming to collect, and a typical trade-off is that the survey line spacing is set to be significantly larger than the trace spacing along the lines. This introduces a strong resolution bias in the 3D dataset, and spatial aliasing is commonly present in the across-line direction. Although simple interpolation methods may be considered to address this problem, they generally lead to overly smoothed and unrealistic results.Here, we present a means of overcoming this issue via multiple-point geostatistics (MPS) simulation. Considering that we have a limited number of sparsely distributed 2D GPR profiles to begin with, we reconstruct the densely spaced 3D GPR data set using a series of separate 2D simulations in both the along-line and across-line directions. Training images, which are necessary for the application of MPS, come from the existing GPR profiles. To deal with the discontinuities in 3D spatial structures caused by performing independent 2D simulations, target profiles are selected randomly but simulations are performed alternately in both directions. Test results show that this methodology provides significantly better reconstructions than standard interpolation, in particular as the spacing between the GPR survey lines increases.
Transformation of internal solitary waves under ice cover edge
Authors: Terletska Kateryna , Maderich Vladimir , Tobisch Elena
Published: February 2023

Internal wave-driven mixing is an important factor in the balance of heat and salt fluxes in the Polar Regions. The interaction between internal waves and ice cover in these areas of the ocean is complex and depends on both the characteristics of the ice and the characteristics of internal waves. Harsh environment in Arctic Ocean obstructs direct field observations of internal solitary waves thus, numerical modellings are an essential tool to overcome this shortcoming. The numerical three dimensional, free-surface, non-hydrostatic model for stratified flows using the Navier-Stokes equations in the Boussinesq approximation so called NH-POM was used for simulations of transformation of internal solitary waves under ice cover edge. As the result of the research it was shown, that propagation of internal solitary waves under edge of the ice cover may lead to their destabilization through overturning and breaking events. Such parameters as ice cover depth and internal waves amplitudes were responsible for the evolution and disintegration of an ISW beneath the ice cover while the boundary friction beneath the ice cover had little effect. During the interaction, maximum energy loss could reach about 60% near the ice edge. Interaction of ISWs with the ice edge significantly enhanced the turbulent dissipation and consequentially could potentially accelerated melting of the ice. It was suggested that the blocking parameter B, that is ratio of incident amplitude to the depth of the upper layer beneath the ice, controls the transfer of energy across the ice edge, that is, more energy is reflected if the ratio increases. When the ice depth decreased, the ice-ISW interaction and resultant dissipation weakened.
Observing, measuring and tackling air pollution with citizens and elected officials: the case of public policy and technical democracy about particulates matter issue in Montpellier, France.
Authors: Dosias-Perla Davia , Lefevre Margaux , Camps Pierre
Published: February 2023

In the context of a double democratic and environmental crisis, participatory/collaborative action-research has multiplied in recent years with increased attention from institutions. Over the last ten years, many participatory research projects have taken up the democratic and environmental crises by proposing an emancipatory normative scheme to improve public participation and the effectiveness of environmental action.Our paper presents the first results of a participatory science project, BREATHE, funded by the ANR. It aims to articulate two components : (1) a participatory measurement of fine particulate matter (PM) concentration (PM 10 - PM 2.5 - PM 1 - PM 0.1) and an identification of pollution sources) from passive filters (plants and sensors) and micro-sensors subject to standardization (2) a component of accompaniment and support of public policies based.The project is based on a participatory science protocol (Chevalier and Buckles, 2009) based on participation engineering (Dosias-Perla et al., 2020). Our fieldwork covers three targets: (a) the incinerator (waste recovery center) - (b) a highways around a small town; (c) a street canyon, city of Montpellier, south of France. On the metrological level, the project aims at analyzing the implication and the effects of the Citizen Science device aiming at "co-constructing" at micro-scales a fine cartography of fine particles concentrations while discriminating the source and modeling the dispersion phenomena. On the political level, the project aims on the one hand to analyze the institutionalization process of the device and on the other hand to analyze its effects on the "co-production" of public policies and strategies through different regulatory frameworks (EPZ, PCAET, Mobility Plan, etc.).We will also discuss the limits and contributions of this type of interdisciplinary and participatory approach aiming at acting on pollution with and for society. We will present current results and first analyses concerning the complex intertwining of technical and political issues related to air quality metrology, the importance and difficulties of standardizing measurement and of truly developing metrology at relevant scale levels when it comes to supporting public action and addressing health issues
Seismic imaging of shallow magma bodies at Krafla, Iceland.
Authors: Maaß Regina , Bean Christopher J. , Li Ka Lok
Published: February 2023

Imaging the subsurface geology at volcanoes is crucial for understanding their structure and dynamics. Knowledge about the existence of magma chambers, fault and fluid systems improves natural hazard assessment and geothermal energy exploitation. However, the highly heterogeneous subsurface at volcanoes complicates the identification of geologic layers and objects. A strongly scattered seismic wavefield is typically recorded that masks coherent energy reflected at interfaces of interest. In addition, small geologic features such as magma bodies are often smeared out by tomographic techniques. A well-known example that highlights this problem is Krafla, a volcano caldera in the north-east of Iceland. In 2009, a magma body was unexpectedly found at a depth of 2.1km during drilling for geothermal purposes. Even though Krafla is one of the best-studied volcanoes worldwide, the shallow magma body remained undetected. In the summer of 2022, we conducted a six weeks long field experiment at Krafla as part of the IMPROVE project. We deployed densely spaced short seismic profiles comprising 114 seismometers in a passive experiment. Our goal is to image the magma body at 2.1 km depth. At first, we carry out a comprehensive data characterization in order to better understand the seismic wavefield and the influence of source, propagation, and near-station effects. In a subsequent step we apply targeted imaging methods including local earthquakes and high-frequency industrial noise. Krafla provides an optimal setting to test and calibrate seismic imaging, because the location of the magma body is known (through drilling). By combining different methods, we seek to improve seismic imaging techniques in order to obtain a high-resolution image of the subsurface in complex media.
First measurements of spatial NO2 variability in Bremen with a newly developed tram DOAS instrument
Authors: Lange Kezia , Richter Andreas , Behrens Lisa K. , Burrows John P.
Published: February 2023

Mobile DOAS measurements are a good option to determine the spatial distribution of NO2 or other trace gases such as HCHO and SO2 within a city. In previous works, such measurements have been performed using cars and have provided interesting insights into spatial inhomogeneities of the NO2 distribution and valuable contributions to satellite validation. A disadvantage of car DOAS measurements is the time required for driving the car.Therefore, a new DOAS instrument was developed and installed on a tram in Bremen in November 2021. The instrument is mostly operating in zenith-sky mode, but also takes measurements at 20° elevation every 7 minutes. The advantage of the tram DOAS instrument is that it performs measurements during the normal operation of the tram. As a result, regular measurements along the route network can be carried out without additional time spent driving.Up to now, the instrument has gathered one year of data all over the Bremen tram network. It can be clearly seen that the areas of increased tropospheric NO2 VCDs change throughout the day, but certain areas show reproducibly higher NO2 pollution. We found elevated NO2 levels in the industrially dominated northwest and lower levels in the more rural northeast of Bremen. This is confirmation for a very similar distribution visible in the TROPOMI tropospheric NO2 VCDs data. In addition, the tram DOAS measurements are compared to the measurements from a stationary MAX-DOAS instrument installed close to one of the tram lines.   