bluuebunny/crossref_metadata_2025 huggingface dataset:
Do detrained cirrus clouds have memory of the deep convection they came from?
Authors: Horner George , Gryspeerdt Edward
Published: February 2023

The large cirrus outflows that arise from deep convection play a vital role in modulating the energy balance of the Earth’s atmosphere. One important question is how much do the initial conditions of the deep convection influence the subsequent evolution of the detrained cirrus, and if these initial conditions are important, over what timescales do they matter? Characterising how these cirrus outflows evolve over their entire lifetime, and how they might change in response to anthropogenic emissions is important in order to understand their role in the climate system and to constrain past and future climate change.Building on the ‘Time Since Convection’ product used in Horner & Gryspeerdt (2023), this work investigates how the initial conditions of the deep convection influence the subsequent evolution of the detrained cirrus- in particular, how does the timing, location, and meteorological environment of the deep convection alter the detrained cirrus, and for how long are these initial conditions important for the cirrus properties- is there a ‘memory’ of the initial conditions of the deep convection imprinted on the properties of the cirrus hours or days after the initial deep convection has dissipated? To answer this question, data from the DARDAR, ISCCP, and CERES products are used to build a composite picture of the radiative and microphysical properties of the clouds, which is investigated under varying initial conditions.The initial state of the convection is found to have a considerable impact on cirrus development under a variety of conditions. The diurnal cycle, particularly the timing of the convection, is a strong control on the cloud radiative effect, particularly in regions of strong convective activity. The initial aerosol perturbation is also shown to play a role in cirrus development, both in the large scale properties of the cirrus and the microphysical properties.This demonstrates a potential time dependent impact of aerosol and convection on cloud properties and provides a template for future studies of cloud development incorporating diverse sets of measurements.
When a hydrothermal system is shaken by the magmatic fluids: the thermal area of Levante Bay during the 2021-22 unrest of La Fossa volcano (Vulcano Island, Aeolian Archipelago)
Authors: Federico Cinzia , Paonita Antonio , Bellomo Sergio , Di Martino Roberto Maria Rosario , Gattuso Alessandro , La Pica Leonardo , Lazzaro Gianluca , Longo Manfredi , Pecoraino Giovannella , Pisciotta Antonino Fabio , Sortino Francesco
Published: February 2023

The INGV monitoring system operating in the volcano Island since three decades, recorded a new phase of unrest at the La Fossa volcano since September 2021. The main set of the crisis was the central hydrothermal system, deeply affected by the input of heat and chemicals from the magmatic source. The Levante Bay, located northwest of the La Fossa edifice, is a thermal area, where the vapor, coming from a local hydrothermal aquifer, is emitted from several low temperature (100°C) fumaroles along the beach and in the near off shore. The composition of the gas is typical of hydrothermal systems, and indicates equilibrium at temperature close to 200°C. By the onset of the crisis, in September 2021, the composition of the gas emitted from these fumaroles showed a smooth trend of increasing contribution of the magmatic gas. In May 2022, a sudden release of gas occurred in the Levante Bay, which was testified by the whitening of the seawater in the bay, due the formation of sulfur flakes, and by the appearance of typical pockmark structures on the seafloor. The drastic increase of the gas flux from the underwater gas vents, coupled to the presence of the pockmarks, suggested that an explosive emission of gas occurred in May 2022. The chemical and isotopic composition (He and C isotopes) of the gas emitted from the fumaroles revealed the prevailing presence of the magmatic component, closely approaching the composition of the gas emitted from crater fumaroles. This episode drove the attention of the scientific community to this area, currently affected by a significant input of the magmatic vapor, because of the risk related to the huge gas emission and the eventual overpressurization of the local hydrothermal aquifer.
Timely mapping and quantification of volcanological parameters: the 2021-2022 Etna lava flows
Authors: Proietti Cristina , De Beni Emanuela , Cantarero Massimo , Ricci Tullio
Published: February 2023

The 2021 eruptive activity at Mt Etna was characterized by 57 paroxysmal events at the South-East Crater, the most active among its four summit craters. These episodes of Strombolian activity and high lava fountains fed lava flows towards East, South, and South-West and caused ashfall in the surroundings of the volcano. In 2022 the SEC gave rise to only two paroxysms in February and effusive activity in May-June and since November (still ongoing). Although the impacted area does not include permanent infrastructures it is of high tourist attraction. Hence, timely mapping of each lava flow field was mandatory for hazard mitigation. The high frequency of the 2021 paroxysms, up to two events in 24 hours, forced us to implement a multidisciplinary approach based on various remote sensing techniques, with different spatial resolutions and revisiting time. In particular, several satellite images were processed, depending on data availability and weather conditions. Data acquired by Sentinel-2 MSI, Skysat, Landsat-8 OLI, and TIRS allowed us to map the lava flow fields at a spatial resolution ranging from 0.5 to 90 meters. High-spatial resolution (from 4.5 up to 55 cm) DEMs and orthomosaics were also realized elaborating the visible and thermal images acquired through Unmanned Aerial Systems (UASs) surveys. Moreover, data acquired by the thermal cameras of the Istituto Nazionale di Geofisica e Vulcanologia permanent network were re-projected into the topography for analyzing the lava flow field evolution at 5-meter spatial resolution. These multi-platform remote sensing data allowed for mapping the lava flows and compiling a geodatabase reporting the main geometrical parameters (e.g. length, area, average thickness, and volume). The resulting multi-sensor methodology enabled, for the first time on Etna, to timely and accurately characterize frequently occurring effusive events.
Socio-hydrological pathways: Cryosphere changes and adaptation strategies in the Trans-Himalaya of Ladakh, India
Authors: Nüsser Marcus , Brombierstäudel Dagmar , Soheb Mohd , Schmidt Susanne
Published: February 2023

The Himalayan cryosphere is shrinking at an accelerating rate. This alarming trend is accompanied by more frequent natural hazards that threaten exposed mountain communities. Problems range from damages of irrigation canals and eroded fields to massive destruction of human habitat. Predicted changes in meltwater supply, modelled under the generic term ‘peak water’, require greater and concerted effort to understand and support local adaptation strategies to cope with experienced and predicted water scarcity. Regional development processes are further characterised by rapid and largely unplanned urbanisation, infrastructure development and related environmental degradation exacerbating risks for large numbers of people already affected by climate change. To meet these grand challenges, an interdisciplinary research perspective is needed for the Himalayan region based on the integration of natural and social sciences. Therefore, an improved understanding of socio-hydrological pathways is necessary to capture local and regional particularities and dynamics, including cryosphere changes, glacio-fluvial runoff, socioeconomic processes, indigenous environmental knowledge, and external development interventions. Based on a long-term study conducted in the Trans-Himalayan region of Ladakh, we explore the role of land use changes, water harvesting infrastructures, including implementation of ice reservoirs (so-called “artificial glaciers”) and construction of improved irrigation networks. Furthermore, the role of social institutions ranging from village to non-governmental organizations and state-sponsored development programs are considered. The presentation uses the case study of Ladakh to develop a grounded socio-hydrological framework for the fragile Trans-Himalayan region that may be used as a basis for sustainable development pathways.
Heat waves and climate change: an application to Sicily (Italy)
Authors: Francipane Antonio , Cipolla Giuseppe , Tomasino Indra , Noto Leonardo Valerio
Published: February 2023

Nowadays, the effects of global warming are becoming increasingly evident and dangerous at every latitude of the planet. In such a context, the Mediterranean basin turns out to be a "hotspot". Reductions in precipitation, especially in the summer season, and increases in the intensity and frequency of extreme events, such as droughts and heat waves, have been observed in regions bordering the Mediterranean Sea in recent decades. In particular, heat waves may have numerous negative impacts on human health, environment, agriculture, and the energy sectors. Indeed, consecutive days with extremely high temperatures, combined with high humidity, poses a high health risk to the population. Moreover, in combination with other extreme events such as drought, they can also promote the occurrence of forest fires causing further damage to ecosystems.The goal of this work is to analyze the characteristics of heat waves that have occurred in Sicily over the last two decades, from 2002 to 2021, to assess the existence of any trend over the period under consideration. For the identification and characterization of the heat waves, hourly data of air temperature and relative humidity have been collected from 101 stations of the Sicilian Agrometeorological Information Service (Servizio Informativo Agrometeorologico Siciliano - SIAS) network. Heat waves have been defined on the base of three variables at the daily scale: maximum air temperature, minimum air temperature, and daily maximum values of the Heat Index, which puts together temperature and relative humidity. A heat wave is detected when the daily maximum/minimum air temperature and the maximum daily Heat Index value exceed for at least two consecutive days the value of a threshold usually calculated as a function of the 90th percentile of the distribution of daily maximum/minimum temperatures and daily Heat Index. For each year, the number of events, number of days of heat waves, duration of the longest event, magnitude of the season (i.e., the number of days between the first day of the first heat wave and the last day of the last heat wave), and intensity (i.e., the average of the differences for each event between the mean temperature value and the threshold to define the occurrence of the heat waves) have been assessed. A trend analysis has been carried out by means of a simple linear regression on all the above-mentioned variables. Results reveal increasing trends for most of the Sicilian gauges, although not for all the above-mentioned variables, showing that in the last 20 years the frequencies of occurrence and magnitude of heat waves have increased, most likely as a climate change effect, and confirming what other studies have found out for other Mediterranean regions in the last years.
Validation and intercomparison of ocean surface circulation analyses and forecasts
Authors: van Gennip Simon , Dubost Flavie , Gouvenou Pierre , Smith Gregory , Surcel-Colan Dorina , Ngueto Yves Franklin , Régnier Charly , Cailleau Sylvain , Levier Bruno , Law-Chune Stéphane , Drevillon Marie
Published: February 2023

Operational systems provide daily surface velocities that reproduce as closely as possible the state of the ocean, a field that lays at the base of many diverse applications such as routing or search and rescue. There’s a growing need to assess different systems’ ability to reproduce ocean dynamical processes covering a range of spatio-temporal scales so to inform on their suitability for use in a vast range of users’ applications.Here we present an initiative for putting in place a multi-metric validation platform for the comparison of ocean currents making use of a number of service evolution developments and concepts (MEDSUB py_eddy_tracker, HIVE…). Such tool is aimed at being operable in any region of interest, applicable to any Copernicus Marine products on the Wekeo DIAS cloud access service.We show an intercomparison of the mesoscale eddy field of different Copernicus Marine systems in the IBI area, together with a range of statistical metrics on surface currents (Eulerian and Lagrangian) comparing against drifting buoys’ velocity measurements. The use of this platform is illustrated with the case of the Grande America catastrophe within the Bay of Biscay in March 2019 to analyse the currents and in fine to help decision-making. Such approach is shown to provide relevant user-oriented uncertainty information for a range of applications.
Long-term (1953-2020) changes in morphology of Chikugo River, Japan in response to natural and anthropogenic forces
Authors: Azhikodan Gubash , Phyu Pan Ei , Yokoyama Katsuhide
Published: February 2023

The sediments transported by the rivers are the primary source of materials to the downstream estuaries and tidal flats. Hence, human activities and increased natural forcing (driven by climate change) can strongly influence the sediment supply by the rivers to the downstream. This can directly impact the existence of tidal flat areas, the rate of bank erosion, and the health of the aquatic ecosystem. A quantitative analysis of the changes in river morphology on a long-term basis is necessary to understand the current situation and develop management strategies. Therefore, this study aims to analyze the long-term (1953-2020) changes in the riverbed elevation of the Chikugo River, Japan. This 143 km long river has a macrotidal estuary downstream (0-23 km). The bathymetric data measured at 200 m intervals from the river mouth (0 km) to the upstream (64 km) for 68 years (1953-2020) was collected from the Japanese government. Further, topographic data in the upstream estuary (10.2-17 km from the river mouth) at 1 km intervals were surveyed for 17 years (2005-2021).Based on the time of human activities and disasters occurrence, the study period was divided into three periods: (1) the period of human activities (1953-1998), (2) the period of no human activities and no disasters (1998-2003), and (3) period of disasters (2003-2020). During period-1, the riverbed of the whole river was lowered, with maximum degradation occurring between 20-30 km. This was caused by extensive human activities such as dredging for flood control and land reclamation and sand mining for commercial use. During period-2, the riverbed (23-64 km) became stable because the dredging was stopped. However, bed elevation in the estuary (0-23 km) increased by nearly 1 m due to tide-induced landward sediment transport. During period-3, extreme floods and landslide disasters supplied massive sediments into the Chikugo River, which was deposited between 30 to 64 km and increased the riverbed elevation. However, the riverbed between 23 to 30 km was almost stable and the bed elevation in the estuary was (6-23 km) decreased. It seemed that sediments supplied by disasters were trapped by a bed sill located at 28.7 km and were not enough to reach the estuary. Further, the extreme flood discharge was strong enough to erode the sediment deposited upstream of the estuary by the tidal forcing and transport back downstream. The erosion of existing deposits and lack of sediment supply from the upstream caused the decreased bed elevation of estuarine areas. According to the results, the river is redistributing and restoring the sediments supplied by disasters at the place of extracted sediments in the past, which has reached mid-stream currently and is expected to arrive at the estuary and downstream soon.
Observation of the microseismic peak from Distributed Acoustic Sensing (DAS) measurements at the LSBB underground Laboratory
Authors: Sèbe Olivier , Jestin Camille , Vallage Amaury , Gaffet Stéphane , Boyer Daniel , Cavaillou Alain , Decitre Jean-Baptiste , Lallemand Charly , Lanticq Vincent , Rousseau Olivier
Published: February 2023

Thanks to its ability to provide dense strain rate measurements along Optical Fiber (OF) cable, the Distributed Acoustic Sensing (DAS) technique spreads over different seismic and geophysical domains. They range from exploration geophysics (Mestayer et al. 2011, Daley et al. 2013), to underground structure imaging (e.g. Ajo-Franklin et al. 2019, Cheng et al. 2021) or seismic activity and background noise monitoring (Jousset et al 2018, Nayak et al. 2021). Beyond the advantage of its dense spatial sampling and given a better understanding of its instrument response (e.g. Lindsey et al. 2020), the detection performance of these new DAS measurements also depends on its ability to precisely characterize the amplitude and phase of the seismic background noise in different environments. According to recent offshore seismic noise studies (Ugalde et al. 2021, Lior et al. 2021, Guerin et al 2022), we propose a study based on DAS recordings of the seismic background noise in an on-land quiet environment.In 2020, a temporary seismic experiment PREMISE (PREliminary MIga Seismic Experiment) was carried out on the site of the underground low noise Laboratory (LSBB, Laboratoire Souterrain Bas Bruit) at Rustrel, France, in order to study the 3D seismic wave field properties in a pretty well-known underground geological structure. During this experiment, we deployed several kilometers of different OF in the LSBB galleries in order to create a multidirectional DAS array with a total fiber length of 10.5km and several ground-coupling conditions. We reprocessed two hours of “raw” DAS data, recorded with a FEBUS A1-R instrument, with different acquisition parameters to find the best configuration for enhancing the DAS measurement Signal to Noise Ratio. The power spectral density (PSD) of these reprocessed strain time-series reveals a peak in the background noise frequency range [0.08-0.25Hz] for gauge lengths of 90m and 150m. Independently, an estimation of the local strain field has been derived by a geodetic analysis (Spudich et al 1995) of the records from the LSBB broadband seismometers antenna. The comparison of the DAS and seismometers array-derived strain PSD shows a very good agreement with the secondary microseism peak in terms of frequency band, amplitude, and the wave field polarization, especially for DAS strain records processed with gauge-length of several tens of meters.
Sea level rise hazard in exposed coastal urban areas of Portugal mainland
Authors: Trindade Jorge , Zêzere José Luís , Reis Eusébio , Rocha Jorge , Silva Andreia , Oliveira Sérgio , Santos Pedro Pinto , Garcia Ricardo , Pereira Susana , Pinheiro Samuel
Published: February 2023

Coastal areas are amongst the most dynamic systems. Flood and coastal erosion hazards are often present at the coastal zone together with human settlements high population density. This leads to high levels of exposure and vulnerability and to frequent damaging events affecting the coastal population, infrastructure and assets that will be amplified by mid- to long-term expected sea level rise (SLR). This research aims to delimitate the coastal hazard zones due to SLR in the Portuguese mainland and for future emission scenarios in 2040, 2070 and 2100. It aims also to assess the possible impacts on the built environment by predicting land use land cover (LULC) changes based on the recent past coastal urban area’s evolution.The two-step methodology includes: a) identification of the SLR hazard zones (SLRHZ) based on the biophysical classification of coastal systems, on the 2040, 2070 and 2100 projected maximum high tide line of equinoctial living waters for the 2.7, 4.5 and 8.5 shared socioeconomic pathways (SSP) scenarios, added with the expected levels of storm surge and run up, and on the maximum expected coastline retreat for the same scenarios; b) assessment of the coastal zone built environment changes through recent LULC dynamics (1995 – 2018) and scenario modelling for the reference years and SSP taking into account present day land use planning restrictions.Preliminary results show: (i) high dependence of SLRHZ on the type of coastal system, (ii) high regional/local contrast on the expected extent of the SLRHZ, mainly when considering the areas exposed to coastline retreat, wave overtopping and overwash; (iii) relatively low impacts of the permanent flooded areas due to SLR in the built environment; (iv) a steady rise in the built environment in the coastal area and consequently in the exposed elements in the SLRHZ; and (v) an increase in the exposed urban areas in the upcoming years according to the assumed scenarios.Acknowledgements: Research financed through Foundation for Science and Technology, I. P., in the framework of the project “HighWaters – Assessing sea level rise exposure and social vulnerability scenarios for sustainable land use planning” (EXPL/GES-AMB/1246/2021).
Digital Outcrop Acquisition for the Observatory of the Vadose Zone (OZNS)
Authors: Laurent Gautier , Mallet Celine , Dewez Thomas , Lefrançois Louis , Abbar Bouamama , Abbas Mohamad , Azaroual Mohamed
Published: February 2023

The Observatory of the Vadose Zone (OZNS) is addressing the role of the unsaturated zone in the transfers of water, heat, and pollutant, between the soil and the aquifer. This project implements a unique observatory within the Beauce Limestone Formation at Villamblain (France). This observatory consists of a large central well (20 m deep and with a diameter of 6.1 m) surrounded by satellite drill holes and surface installations within an area with a radius of a few tens of meters. The overall observatory spans from the surface down to 25 m depth, reaching the aquifer and the barrier layer of the Molasses du Gâtinais. The instrumented surface, central well, and satellite drill holes will produce decade-long records of the vadose zone to evaluate its impact on water and pollutant transfers, while monitoring its long-term evolution in a context of climate change.
 The large central well is primarily designed for easily installing, maintaining, and testing geophysical and hydrological sensors over the lifetime of the observatory, but it also provides a unique chance to observe the complex structuration of the vadose zone and its host. In particular, the scale and configurations of the site provide a unique view of these rocks. They are made accessible at a micro-to-decametric scale, which extends drill core observations, and provide a nearly 3D view. This is interesting by comparison with typical outcrops at that scale (e.g., quarries), which are mostly 2D. Preliminary observations, from surrounding drill cores, revealed a particularly complex limestone formation, which consists of a series of terrestrial limestones, with palustrine and lacustrine facies and breccias, affected by a long history of fractures and alterations, silicification, and karstification. A very detailed characterisation of these facies thus requires to provide a high-resolution context for the various measurements and simulations of the transfers in the vadose zone.This contribution presents the construction of the numerical architecture and the acquisition process implemented for accommodating the very restricted access to direct observations during the construction of the well, which encompasses laser scanning (lidar) and high-resolution photogrammetry. The implications of the different acquisition protocols implemented during the process are discussed in terms of impacts on resolution, coverage, and spatial accuracy. The scanning was performed through 14 distinct stages, where only around 1.5 m height was accessible each time. One of the challenges was thus to stitch the different model rings into a common model. In the end, a complete model of the well surface was recorded with an average resolution of 3 pixels per millimetre.
Dust aerosols’ mineralogy in the chemical transport model COSMO-MUSCAT during JATAC and comparison with lidar and in-situ data
Authors: Gómez Maqueo Anaya Sofía , Althausen Dietrich , Schepanski Kerstin , Faust Matthias , Heinold Bernd , Tegen Ina , Baars Holger , Engelmann Ronny , Skupin Anett , Radenz Martin , Ansmann Albert , Hesse Birgit , Wandinger Ulla , Mocnik Grisa , Silva Eder , Rodrigues Elizandro , Silva Pericles , Zenk Cordula
Published: February 2023

Mineral dust aerosols are composed from a complex assemblage of various minerals depending on the region they come from. Considering that minerals have their distinct physicochemical properties, differences on mineral dust aerosols climatic impact will arise as a consequence of distinct mineral content.Chemical transport models typically assume that mineral dust aerosols have uniform composition, despite the known regional variations in the mineral components. This study adds mineralogical information to the mineral dust emission scheme used in the chemical transport model, COSMO-MUSCAT.Here we show some steps of the inclusion of mineralogy to the emission scheme. Results of the simulated mineral dust aerosols are shown with their respective mineralogy from sources in Africa for an example case from the JATAC campaign in September 2021. The results of the simulated mineral dust aerosol are compared with lidar and in-situ data measured at Mindelo, Cape Verde. Furthermore, the comparison with the lidar retrieved vertical profiles at Mindelo, highlights a possible link between the mineral dust aerosol optical properties and the distinct minerals found within them.
A model weighting scheme for fire weather projections simulated by CMIP6 climate model ensembles
Authors: Gallo Carolina , Eden Jonathan , Dieppois Bastien , Drobyshev Igor , Fulé Peter , San-Miguel-Ayanz Jesús , Blackett Matthew
Published: February 2023

Weather and climate play an important role in shaping global fire regimes and geographical distributions of burnable areas. At the global scale, fire danger is likely to increase in the near future due to warmer temperatures and changes in precipitation patterns, as projected by the Sixth Assessment Report (AR6) of the Intergovernmental Panel on Climate Change (IPCC). There is a need to develop the most reliable projections of future climate-driven fire danger to enable decision makers and forest managers to respond to future fire events.Climate change projections generated by general circulation models, especially those that contribute to the 6th Coupled Model Intercomparison Project (CMIP6), are the most important basis in understanding future changes in fire-conducive weather and climate associated with a warming world. However, errors and biases inherent to such models are rarely taken into account when generating climate change projections. For fire weather in particular, projections have typically been expressed by a single model or through a multi-model mean. This approach can be misleading, as it explains little about the consensus among different models and their uncertainties. Here, following a comprehensive evaluation of the performance of 16 different CMIP6 climate model ensembles, we present new scenarios for detecting changes in fire-prone conditions based on a statistical weighting approach that accounts for both model skill and independence. We demonstrate the value of a weighted approach in accounting for and reducing model uncertainties, and more generally in the development of fire weather scenarios that ultimately as useful as possible. In conclusion, we make recommendations for how the new set of scenarios can benefit end users in decision-making and forest management.
Using the Debye parameters of soil for water content and contamination level determination.
Authors: Farrugia Lourdes , Persico Raffaele , Cataldo Andrea , Farhat Iman , Schiavoni Raissa
Published: February 2023

The use of time domain reflectometry (TDR) techniques for in-situ, non-destructive measurement of water content has revolutionized soil water management and it is a rapidly growing area of interest. Additionally, monitoring other soil parameters such as levels of contaminants in soil is becoming an active field of research due to increasing environmental pollution and thus enforcement of contamination levels from policy makers. As a result, in recent years there have been advancements of TDR probe capability in terms of operating range, proven design, multiplexing and automated data collection. However, there is still a strong need for systems that are user-friendly and low cost which provide for quasi-real time and in situ monitoring with high sensitivity of soil parameters with adequate accuracy.In this paper, we present a system consisting of a bifilar TDR probe interfaced with a miniaturized Vector network analyser which enabled measurements of the reflection coefficient in the frequency-domain.   The reflection coefficient is then related to soil parameters, such as soil water content and percentage of diesel oil (as an example of soil contaminant) through an innovative numerical procedure that retrieves the Debye parameters of different soil samples under different conditions.This numerical procedure consisted of two main steps:Firstly, the accurate modelling of the bifilar TDR probe in CST Microwave Studio such that the model is an accurate representation of the experimental setup used in the laboratory. This model was also validated using well-characterised materials such as Methanol and Prop-2-ol, utilising Debye parameters as published in [1].Finally, the bifilar probes were immersed in soil samples having different moisture levels (dry up to 30%, in steps of 5%) and contaminated soil with different percentages of diesel oil (0%, 5%, 7.5% and 10%) and the Debye parameters were retrieved using the validated model in the first step.Results illustrate that there exists a correlation between the retrieved Debye parameters and the moisture levels and percentage of diesel oil in soil. This proves that the Debye parameters provide the necessary information to differentiate between water or contaminant content and thus can be used for monitoring purposes rather than conducting measurements of the dielectric permittivity. References[1] Gregory, A.P.; Clarke, R.N. Tables of the Complex Permittivity of Dielectric Reference Liquids at Frequencies up to 5 GHz; National Physical Laboratory Report; 2012. Available online: https://eprintspublications.npl.co.uk/2076/ (accessed on 13 September 2022).
Satellite Investigation to study POcket BEach Dynamics in Malta. The SIPOBED project
Authors: Galone Luciano , Colica Emanuele , Iregbeyen Peter , Piroddi Luca , Gauci Adam , Deidun Alan , Valentino Gianluca , D'Amico Sebastiano
Published: February 2023

Pocket Beaches are small beaches limited by natural headlands, strongly jutting into the sea, free from direct sedimentary contributions that are not eroded from back-shore cliffs. Malta’s pocket beaches are one of the most significant geomorphologic features of the archipelago. They play an important role for a variety of ecological and economic reasons. In this sense, sediment (mostly sand) dynamics is the most relevant factor to consider in the beach system. Sediment movement can be driven by a variety of factors, including wave action, currents, wind and direct and indirect anthropic action, leading to extreme morphological modifications in some cases.The SIPOBED (Satellite Investigation to study POcket BEach Dynamics) project seeks to develop a reliable and cost-effective tool capable of monitoring sediment dynamics using satellite and other remote sensing data in several selected Maltase Pocket Beach systems, by reconstructing the volume and distribution of sediment of the beaches system through time.The monitoring of sandy coastal zones requires the analysis of sediment dynamics in the entire beach system, from the coastal dunes to the closure depth, where the influence of sea waves on the seabed is low. SIPOBED uses Interferometric SAR and Light Detection and Ranging (LIDAR) derived Digital Elevation Models (DEMs) to study the inland system dynamics. The DEMs are used to improve the co-registration of temporal SAR imagery and detect subtle changes between acquisitions. The underwater sediment dynamics monitoring is approached by tracking bathymetric changes using multispectral satellite and unmanned aerial vehicle (UAV) images. In situ bathymetric data is essential for calibrating and validating the model. This methodology allows for more frequent and cost-effective monitoring of changes in both the dune-beach system and the ocean floor compared to classical approaches, such as in situ topographic surveys and ship-based sonar surveys. The project also aims to determine the bedrock depth and geometry at the lower limit of the pocket beach system using near-surface geophysical techniques.The monitoring of Maltese sandy coastal beaches can provide insights into the factors influencing sediment dynamics and improve our understanding of the processes that shape and reshape pocket beaches over time. The results of the SIPOBED project will contribute to developing a risk assessment and monitoring tool that combines the sediment dynamics process with their potential local impacts, resulting in a powerful instrument for decision-makers.The SIPOBED project is financed by the Malta Council for Science and Technology (MCST, https://mcst.gov.mt/) through the Space Research Fund (Building capacity in the downstream Earth Observation Sector), a programme supported by the European Space Agency.
Implementation of ITRF2020 in the ILRS Operational Products
Authors: Luceri Vincenza , Basoni Antonio , Sarrocco David , Pavlis Erricos C. , Kuzmicz-Cieslak Magda , Evans Keith , Bloßfeld Mathis , Bianco Giuseppe
Published: February 2023

The ILRS contributed to the development of ITRF2020 via the combined products submitted to ITRS. The combined products were the result of the combination of individual AC contributions where a new approach in handling systematic errors at the stations was implemented. A set of a priori estimated mean biases was considered for the main period 1993-2020 that includes data from LAGEOS, LAGEOS-2 and the Etalons, whereas an adjusted 15-day average bias at each station for the 1983-1993 period was considered to accommodate systematic and target signature errors, if a priori mean biases were missing. The implementation of ITRF2020/SLRF2020 in SLR operational products required an extended version of the SSEM model, SSEM-X, which led to the finalization of a new DH file. Considering this updated set of long-term mean biases, all ACs produced a solution set based on models used for REPRO2020 and SLRF2020 as input to a combined product intended for the IERS RS/PC at USNO. These EOP series will be used for the calibration of EOP biases prior to the release the final version of the new Bulletin A. The new bias model SSEM-X will be publicly available and maintained current over the coming years.
MUCCnet visiting Vienna: refining inverse model prior information with tall-tower flux measurements
Authors: Luther Andreas , Forstmaier Andreas , Tang Haoyue , Bettinelli Juan , Ghaith Gamal , Aigner Patrick , Makowski Moritz , Fasano Enrichetta , Meeran Kathiravan M. , Leitner Simon , Watzinger Andrea , Matthews Bradley , Chen Jia
Published: February 2023

More than two thirds of global anthropogenic greenhouse gas (GHG) emissions originate from cities. Urban mitigation policies need a reliable emission data basis to effectively reduce emissions and given inventory uncertainties at the level of single cities, there is growing interest in measurement-based methods to support urban GHG emissions monitoring. Inverse modelling is a measurement-based approach that integrates atmospheric observations with emission inventories, whereby the inventories serve as prior estimates that are subsequently constrained against the observations. While such inverse systems rely on modelling frameworks that typically utilise in situ and/or remote measurements of atmospheric GHG mixing ratios, there is scope for city-scale inverse frameworks to utilise other types of GHG observations, such as flux measurements.In this study, we investigate such an approach based on a two month field campaign between 15th of May and 20th of July in 2022 in Vienna, Austria. In particular, for the prior information, we use tall-tower eddy covariance observations to constrain the CH4 emissions within the tower's flux footprint and combine the measurements with 1km x 1km inventory data of the larger city area of Vienna. This refined and measurement-supported inventory serves as a-priori information for both, a Bayesian- and a Phillips-Tikhonov based inversion approach. The observational input for the inversion methods is delivered by MUCCnet (Munich Urban Carbon Column network) instruments consisting of four ground-based, sun-viewing FTIR spectrometers (EM27/SUN), with three of these instruments located on the outskirts of Vienna and one instrument located at the bottom of the tall-tower close to the city center. This study investigates the synergetic aspects of two different measurement systems: the eddy-covariance system is particularly sensitive to near field emissions with a range of hundreds of meters upwind of the tower, whereas the ground-based remote sensing instruments observe the differential total column concentration and are therefore sensitive to emissions originating several Kilometers upwind. Applying both measurement systems within a city inversion framework may indeed represent a viable option for further constraining city emissions and improving urban GHG emissions monitoring.
Assessing soil water thresholds for irrigation of maize in north-eastern Austria
Authors: Faller Christian , Nolz Reinhard
Published: February 2023

The consequences of climate change will affect irrigation also in areas that have so far been little affected by water shortages. In the north-eastern part of Austria with predominantly sub-humid conditions (550 mm mean annual rainfall, 11°C mean annual temperature), water demand is expected to double by 2050. With regard to irrigation, this means both increased crop water requirements and reduced water availability. Improving water use efficiency is one way to sustain agricultural productivity and water resources in the long term. This poses a future challenge also for farmers who have had little to do with the requirements of highly efficient irrigation management so far. In this regard, a potential on-farm strategy is to monitor soil water status and control irrigation based on the plant available soil water. On the technical side, sensors and telemetry networks are available that regularly collect and transmit data. However, the appropriate thresholds for irrigation control must also be known. These depend on the crop, the root development, the soil type and the installation depth of the sensors. Last but not least, farmers need to trust the decision support and use the information appropriately. The aim of this study was to determine threshold values ​​for the irrigation of maize at a location in north-eastern Austria (in the country's largest arable farming area, approx. 35 km east of Vienna) and to subject them to a practical test in the field.The irrigation system used was a hose reel with an irrigation boom with rotating nozzles (BAUER GmbH). HydraProbe (Stevens Water Monitoring Systems Inc.) and Watermark (Irrometer Company Inc.) sensors were used to measure soil water content and matric potential, respectively. The sensors were integrated into a telemetry network (ADCON by OTT HydroMet GmbH); data were available via a web-application. For practical reasons, the installation depth of the sensors was set at 20 cm. Soil was a sandy loam. A target value for the maximum allowed depletion under optimal to slightly stressed conditions was calculated using a water balance model. Based on HYDRUS-1D (PC-Progress s.r.o.) simulations, the corresponding matric potential at 20 cm depth was −100 kPa. This value should serve as the target value for irrigation. The soil water content data served as a control for the simulation using the FAO AquaCrop model. The latter was used to evaluate the irrigation carried out by the farmer.The soil water data revealed that the specified threshold was not reached in the practical test. It seems that farmers experience was oriented towards a more sufficient water supply. The simulation showed that water use efficiency could have been improved by using less water; however, in this case a reduction in yield of a few percent would have to be expected. Measuring with only one sensor at a depth of 20 cm proved to be a viable procedure; however, data interpretability could be improved by sensors at several depths.
Connecting the dots: Fracture mapping for landfill sites in fractured bedrock”
Authors: Tariq Bilal , French Helen Kristine , Polteau Stéphane , Anschütz Helgard , Salazar Sean
Published: February 2023

A landfill constructed in fractured bedrock can pose a potential risk of contaminant leachate to the surroundings through fractures and/or fracture networks. Therefore, adequate understanding of factures and fracture networks is a key element for constructing environmentally safe, sustainable and long-term landfills in fractured bedrocks. Mapping of geological features especially fracture networks provides essential data to establish a fundamental understanding of the local geology and hydrogeology of such landfill sites.The objective of this study to develop  a 3D model of fractures and fracture networks, surrounding a quarry in southwestern Norway, Rekefjord. The test site, selected as a potential landfill site, consists of  moderately fractured crystalline monzonorite near the shoreline. Eight previously drilled and logged observation boreholes (NGI) on the crest surrounding the open pit were analysed. Results of subsurface fracture mapping from well logs show that orientations of natural fractures are scattered and mostly appear to be open. The Terzaghi correction shows there could be more steeply dipping fractures, these are not well captured through vertical borehole logging. Additional field work consisted of drone scanning of the interior of the whole quarry and specific locations to generate a virtual 3D model. This 3D model is used to conduct fracture measurements using the LIME software. The fracture data extracted from the 3D model will be used to assess the correlation and consistency in fracture orientation between the internal rock face and borehole measurements. The geometry of fracture networks and individual fractures can have significant impact on flow through fractured rock. Results will also be used to constrain a numerical groundwater flow model to improve understanding of potential pathways of contaminants from the landfill to the surroundings. The results of this research will improve assessment methodology and criteria for new landfill sites in fractured bedrock.
Significant variability in 87Sr/86Sr and d88/86Sr in Hess Deep Rift lithologies due to hydrothermal alteration.
Authors: Haldar Utpalendu , Sensarma Simontini , Chakrabarti Ramananda
Published: February 2023

Hydrothermal alteration of seafloor basalts alters its elemental and isotopic composition. Studies on dredged basalts and ophiolite sequences using stable O, K, and radiogenic Sr [1,2,3] isotopes have documented the effect of seafloor alteration on such lithologies. Experimental studies of basalt-seawater interaction have also demonstrated exchange of Sr isotopic signatures between these two phases [4] while limited data for altered oceanic crust suggests incorporation of heavier Sr isotopes [5]. To further our understanding of the behaviour of Sr during seafloor alteration in natural settings, we measured 87Sr/86Sr and δ88/86Sr in a suite of variably altered lithologies from Hess Deep Rift (HDR), which include basalt, norite, gabbro and troctolite.Radiogenic Sr (87Sr/86Sr) was measured using TIMS (Thermo Scientific, Triton Plus), using internal normalization while stable Sr isotopes (δ88/86Sr, reported relative to NIST SRM 987) were measured using a double spike (84Sr-87Sr) TIMS technique, both at the Centre for Earth Sciences, IISc, Bangalore. The δ88/86Sr values of the HDR samples (0.308-0.810 ‰) are higher than the bulk silicate Earth (BSE) value (0.27 + 0.05 ‰) [6]; some samples show δ88/86Sr values higher than modern-day seawater value (0.386 ‰) [e.g., 7]. The 87Sr/86Sr varies from ~0.703 in unaltered samples to ~0.709 in altered samples, the latter close to the modern-day seawater value. Overall, our data suggests incorporation of heavier isotopes of Sr in altered oceanic crustal samples; the heavier than seawater δ88/86Sr values observed in some samples reflect formation of new mineral phases, consistent with high δ88/86Sr observed in anhydrite formed in laboratory experiments of basalt-seawater interaction[4].[1]. Lamphere et al. (1981) Journal of Geophysical Research: Solid Earth, 86(B4), pp.2709-2720; [2]. McCulloch et al. (1981) Journal of Geophysical Research: Solid Earth, 86(B4), pp.2721-2735; [3]. Parendo et al. (2017) Proceedings of the National Academy of Sciences, 114(8), pp.1827-1831; [4]. Voigt et al. (2018) Geochimica et Cosmochimica Acta, 240, pp.131-151; [5] Klaver et al. (2020) Geochimica et Cosmochimica Acta, 288, pp.101-119; [6] Moynier et al. (2010) Earth and Planetary Science Letters, 300(3-4), pp.359-366; [7]. Ganguly and Chakrabarti 92022) Journal of Analytical Atomic Spectrometry, 37(10), pp.1961-1971.
The importance of meso-scale anoxic spots and events in oxic environments for carbon dynamics and greenhouse gas emissions from terrestrial, riparian and aquatic ecosystems
Authors: van Grinsven Sigrid , Dannenmann Michael , Geist Jürgen , Höß Rebecca , Kögel-Knabner Ingrid , Lei Kaiyu , Völkel Jörg
Published: February 2023

Local environments such as soils and waterways, but also landscape-scale environments such as agricultural areas, are often classified as oxic based on the dominant conditions in such systems. Still, anoxic conditions do occur within these “oxic” landscapes, their upland and lowland soils, sediments and creeks at a wide range of spatiotemporal scales, and can represent hot spots and hot moments for greenhouse gas emissions but also carbon storage due to their strongly deviating biogeochemical character.Within the project “Bavarian landscapes under climate change”, located in the crystalline Bavarian Forest, Germany, we characterize and quantify the role of anoxic spots for greenhouse gas emissions and carbon storage at the scale of agricultural landscapes, including managed grassland and cropland soils, riparian soils and creeks including their special features such as beaver dams. Our focus is on mesoscale anoxic events, at the 1-10 m2 scale, that are the result of temporary conditions, such as flooding or fine sediment deposition. We place these mesoscale events into the context of the whole agricultural landscape and watershed, and characterize the carbon species, gaseous emissions, carbon stocks, and organic carbon degradation dynamics in the different oxic and anoxic parts of our larger system, both aquatic and terrestrial. First results indicate that the enhanced greenhouse gas emissions, but also carbon storage, can be large enough to be relevant offsets of the larger scale (whole stream, riparian zone) carbon dynamics. Ignoring these spatially or temporally relatively small events or locations in upscaling or modeling can thus lead to important underestimations of carbon storage, as well as to offsets of the greenhouse gas balance of an area.