bluuebunny/crossref_metadata_2025 huggingface dataset:
NBS implemented in the Pyrenees during the PHUSICOS project
Authors: Solheim Anders , Vergès Didier , Fabregas Santiago , Lespine Laurent , Räimät Carles , Garcia Eva , Oen Amy , Kalsnes Bjørn , Capobianco Vittoria
Published: February 2023

The H2020 project PHUSICOS designs and implements NBS for DRR at demonstrator case sites in rural areas of Norway, Italy, and in the French and Spanish Pyrenees. This presentation covers four locations in the Pyrenees, where NBS to reduce risk from snow avalanches, rockfall and debris flows are implemented. Snow avalanches from the steep slopes of the Capet Forest threaten the French village of Barèges. The NBS here consist of afforestation in the release areas. 5000 trees have been planted in groups of 30-50, protected behind wooden tripods, which also act as protection structures until the trees are large enough to stabilize the snowpack. Rockfall poses a severe hazard at two locations along the important road A-136 / RD-934 between France and Spain. At St. Elena, Spain, the rocks are released by erosion of a slope in a thick till deposit. The implemented NBS consists of vegetated terraces, built up by a dry masonry wall and gabions constructed from wood and filled with the local till. At the location in Artouste, France, rockfalls in the steep slope are released from exposed ledges and from loose blocks in the till surface. The measures here consist of wooden stabilising and retaining structures for each individual ledge or block. These solutions are also tested at newly established laboratory and full-scale test facilities in Spain and France, respectively. The fourth location is near the Spanish village Erill-la-Vall, where debris flows from a >50m thick till deposit pose the threat. Several gullies feed the main debris flow path towards the village during periods of extreme precipitation. The implemented solution is a series of terraces, built up by local rocks and whole-log gabions in the lower parts of the gullies. These will prevent deepening of the erosional base and form increased rugosity in the debris flow paths. The site has been monitored during the last 15 years. In-situ borehole (piezometer) data shows two processes: a deep-seated (15-20 m) failure level, which reacts up to two weeks after a period of heavy rain, and shallow erosion, which reacts almost immediately as a direct response to heavy precipitation. The implemented NBS are primarily to mitigate against the latter process.The NBS described here all have large upscaling potential, as there are numerous locations in the Pyrenees and elsewhere with similar problems. Terracing and afforestation for slope stabilization is not a new concept but is here re-vitalized in cooperation with stakeholders through Living-Lab processes. These processes have also helped overcoming challenges related to land ownership issues and permissions to operate, e.g., in national parks, which have caused implementation delays. Monitoring of the implemented measures, focused on both the resilience aspect and, not the least, the NBS' co-benefits will be important for building up an evidence-base for the functionality of NBS for DRR.
InSAR tropospheric corrections on Merapi using global weather models and local GNSS network
Authors: Gremion Shan , Pinel Virginie , Albino Fabien , Beauducel François
Published: February 2023

Merapi is a strato-volcano rising at 2900 m a.s.l, located on the South coast of Java island, Indonesia. Only 30 km north to the city of Yogyakarta (2 millions inhabitants), it is considered one of the most dangerous dome building stratovolcanoes, as summit domes almost continuously grow and destruct. Merapi is therefore closely and routinely monitored by InSAR (Interferometric Synthetic Aperture Radar) to track ground deformation. To retrieve ground deformation from the full wave path, the delay due to the radar wave crossing the atmosphere needs to be corrected. In the case of Sentinel-1, interferograms are mostly biased by the tropospheric variations. Tropospheric variations are expected to be stronger in tropical regions and where topographic gradient is high, which is the case at Merapi. They can be estimated thanks to various methods, including global weather models (ERA-5 and GACOS), a linear model regarding topography, and GNSS networks.In this work, we compare the performance of atmospheric corrections derived from two weather-based models, ERA-5 and GACOS, and those derived from the empirical method based on a linear phase-elevation correlation. The aim is to evaluate the efficiency of each model in correcting this tropospheric bias. To this end, we choose to study a period between 2016 and 2018 during which no deformation occurred on the Merapi, so that most of the phase delays corresponds to tropospheric signals.We use three criteria to evaluate the performance: i) the reduction of the standard deviation, ii) the reduction of the sill of the semi-variogram, iii) the slope reduction of the phase-elevation correlation. We show that corrections with ERA and GACOS are efficient on only half of the interferograms. Finally, we also use the local network of 5 GNSS stations to rely on an independent dataset. We show there is a linear relation between the GNSS tropospheric delays and the global weather models delays. However, the GNSS network at Merapi is too small to provide an efficient correction on the whole volcanic edifice. For this reason, a similar workflow has been carried on the Piton de la Fournaise, Réunion island, using a wider GNSS network. The final aim of this study would be to implement a strategy on which the most suitable tropospheric model is chosen routinely based on the evaluation of the performance criteria to obtain atmospheric-free interferograms during volcanic unrest.
Engineering transpiration-induced suction using mycorrhizal fungi with application to slope stability
Authors: Roberts-Self Eve , Tarantino Alessandro
Published: February 2023

The use of vegetation to mitigate rainfall induced landslide hazards is a form of a Nature Based Solution. Rainfall induced landslides occur when the pore-water pressure builds up in the soil in response to infiltrating rainwater. The vegetation can create a stabilising effect by the removal of soil water via transpiration. The removal of water keeps the soil in an unsaturated state and decreases pore-water pressure in the soil, thus reducing hydraulic conductivity. Lowering the hydraulic conductivity before a rainfall event will reduce the downward infiltration of water and, hence, hinder pore-water pressure build-up (drop in suction) that could result in a landslide.To improve this stabilizing effect the transpiration during a drying period should be maximized. This study looks at implementing biological processes that occur in the root zone with the aim of engineering the transpiration process. A common biotic interaction that occurs in the soil is the symbiotic relationship between mycorrhizal fungi and plant roots. The fungus has been found to improve nutrient and water uptake in plants. This research looks at the effect of mycorrhizal fungi on transpiration induced soil suction.A controlled laboratory experiment was carried out to determine if the application of arbuscular mycorrhizal (AM) fungi can increase transpiration of the herbaceous plants Medicago sativa and Lolium perenne. The plants were grown in mini-lysimeters with and without AM fungi and then exposed to drying conditions. The evapotranspiration was monitored via measurements of the change in mass of the mini-lysimeter and the soil water content was then back calculated from the final water content. Periodic soil volumetric water content measurements were also carried out using TDR-probes. The suction during drying was determined from the volumetric water content assuming that the water retention in the vegetated soil is the same as the bare soil, whose water retention properties were fully characterised in a separate experiment.The inoculation with AM fungi in M. sativa plants increased the potential evapotranspiration during soil drying, this is likely due to the increase in the aboveground biomass. There was no significant difference between inoculated and non-inoculated L. perenne plants. The soil suction in the M. sativa plants increased by almost twice when inoculated with AM fungi in the same drying period. Inoculating with AM fungi can increase plant transpiration rates and generates a higher suction in the soil for M. sativa vegetation, although there was little difference with L. perenne plants. This suggests that the effect of AM fungi on plant water uptake can depend on root functional groups.
Flood Risk Mapping in Southern Brazil using a terrain descriptor and socio-economic indices
Authors: Dotta Correa Deborah , Borges Chaffe Pedro Luiz , Boing de Souza José Vinícius
Published: February 2023

Floods are the most frequent natural disaster impacting society and all inhabited continents. Accurately mapping the extent of flooding is challenging as it requires a detailed, computationally demanding and data-limited representation of hydrological processes. This study focused on mapping the flood risk of the Itajaí River Basin, an important basin with an extensive history of flooding in Southern Brazil, using the HAND terrain descriptor and socio-economic indices.  A combination of three factors was used to define the flood risk: hazard, exposure and vulnerability. In order to characterize hazard, we use a parallel implementation in GPU of the HAND terrain descriptor combined with flood frequency analysis. Vulnerability was determined by combining the Human Development Index and population spatial distribution. Finally, the exposure was determined by using nightlights. Floods observed extent maps of the September 2011 50-year event in different municipalities of the Itajaí River Basin were used to determine the performance of the HAND terrain descriptor as a flood mapping tool. The best performance of the model was obtained for Rio do Sul municipality, with a correctness index of 86% and a fit index of 75%. Most of the Itajaí River Basin (93%) was classified as low risk. Of the remaining 7%, 90% was classified as medium risk, 8% as high risk and 2% as severe risk. By using the HAND terrain descriptor and socio-economic indices, a flood risk map of the Itajaí River Basin in Southern Brazil was developed which can be used as a valuable resource in urban planning, including the development of flood mitigation and response measures.
Cloud-driven patterns of surface solar irradiance as seen by a spatial network of radiometers
Authors: Mol Wouter , Heusinkveld Bert , Hartogensis Oscar , van Heerwaarden Chiel
Published: February 2023

Surface solar irradiance varies on scales down to seconds or meters due to clouds. This highly variable nature of irradiance is not resolved by atmospheric models, yet heterogeneity in surface irradiance impacts the overlying cloud field. The inability to resolve irradiance variability, aside from insufficient model resolution, is explained by our limited understanding of cloud-driven solar irradiance variability at short spatiotemporal scales and the lack of high resolution spatial observational data. Cloud resolving models utilizing ray tracing techniques are a useful research tool, but ultimately require validation against observations.In 2021, we gathered new observational data with a network of radiometers, specifically designed to gather data on cloud-driven surface patterns of irradiance. I will present results on various kinds of surface patterns in relation to cloud type and atmospheric conditions, based on these observations. Our radiometers sample surface solar irradiance at 10 Hz for 18 wavelengths, which we deployed in different setups in the FESSTVaL (Germany) and LIAISE (Spain) field campaigns. Our results highlight the complexity and wide range of regimes in spatiotemporal irradiance variability, but also provide insights into its driving mechanisms. These insights help guide the development of improved radiative transfer calculations, in order to move towards models that can accurately resolve irradiance variability in an operational setting.
Hot when wet: the consequences of exothermic hydration on geochronology
Authors: Schorn Simon , Moulas Evangelos , Stüwe Kurt
Published: February 2023

Retrogression and hydration commonly affect large portions of the crust, causing variable degrees of chloritization, sericitization and/or serpentinization depending on the protolith and the conditions of fluid ingression. Retrograde overprint involving hydration is a strongly exothermic process, and leads to a thermal perturbation around the pressure–temperature conditions of hydration, which in the case of chloritization of felsic rocks typically occurs at <500°C. These conditions of retrogression overlap with the closure temperatures of some isotopic systems commonly used for geochronology, for example 40Ar/39Ar in micas and feldspars. The exothermicity of hydration therefore disturbs the recorded apparent ages and cooling histories of reworked terranes. Using an average metapelite composition as case study, we estimate that hydration and retrogression of a high-grade amphibolite facies assemblage to a low-grade greenschist paragenesis involves approximately a twofold increase of the mineral-bound water content and releases about 50 kJ.kg-1 latent heat. Using a simple 1-dimensional numerical model, we solve the heat equation for a steady-state continental geotherm that is advected towards the surface and track the cooling rates for markers that exhume from different depths. Assuming enthalpy production at 380°C to simulate exothermic hydration, the cooling rate is significantly reduced until the markers are exhumed to the temperature/depth of hydration and reaction. The calculated cooling paths feed into KADMOS (Moulas & Brandon, 2022), a set of MATLAB routines designed to calculate apparent 40Ar/39Ar ages as function of customized thermal histories. KADMOS solves the equation of 40Ar production from 40K decay and thermally-activated diffusive loss of 40Ar for time (Fig. 1). Our results reveal that for intermediate exhumation rates, spherical muscovite grains with <100 µm in diameter are affected by a ~10% age error when latent heat is considered (Fig. 1b). Such muscovites in rocks exhuming with a velocity of, for example, 4 mm/year would record an apparent 40Ar/39Ar age of c. 10 Ma (Fig. 1a) and be affected by an absolute age error of ~1 Ma from thermal buffering by hydration, yielding an apparent age of 10 ± 1 Ma (Fig. 1b). Our calculations indicate that latent heat released from exothermic hydration may significantly disturb low-temperature isotopic systems, thereby complicating the cooling histories and obscuring the temporal constraints deduced from state-of-the-art geochronological systems.Figure 1 – Exhumation velocity vs. grainsize contoured for apparent 40Ar/39Ar age in muscovite (a) and relative error when latent heat is considered (b)REFERENCESEvangelos Moulas, & Mark T Brandon. (2022). KADMOS: a Finite Element code for the calculation of apparent K-Ar ages in minerals (Version 1). Zenodo. https://doi.org/10.5281/zenodo.7358138
Physically based slope stability analysis: future scenarios due to changing surface temperature
Authors: Dhakal Om Prasad , Scaringi Gianvito , Loche Marco , Dahal Ranjan Kumar , Bout Bastian van den
Published: February 2023

Temperature significantly affects the hydraulic and mechanical properties of geomaterials on a slope. However, results from the laboratory show the change in material behaviour depends on the slip rates and the type of minerals present. Active clays are observed to be the most sensitive to temperature oscillations in mechanical deformations. In this research, the temperature change effects will be addressed in laboratory experiments on natural soils. We will deploy laboratory samples to obtain the frictional coefficient as a function of temperature (20-50 degrees). Further, reconstituted samples will be tested under different shear rates to understand the dependencies on temperature. Temperature-sensitive parameters (such as the internal friction angle) will be incorporated in a physically-based modelling framework analysing effects for a sloping unit. The factor of safety will be calculated based on spatial grids representative of the sampling location. In the second part of this research, the frictional coefficient obtained from the laboratory as a function of temperature will be synchronised with projected climate change (surface temperature, hydro-meteorological forcing) and will be simulated to a catchment scale multihazard modelling. This model will incorporate measured data and geostatistical interpolation of remotely sensed data to fulfil the dataset to run the physically based equations. The final output will be the comparison of hazard intensities (e.g., debris flow impact pressure, inundation heights, solid velocity and depth) for the projected future years.
Impacts of a weakened AMOC on the European climate
Authors: Bellomo Katinka , Meccia Virna , D'Agostino Roberta , Fabiano Federico , Larson Sarah , von Hardenberg Jost , Corti Susanna
Published: February 2023

Previous studies have shown that the response of the Atlantic Meridional Overturning Circulation (AMOC) to increasing greenhouse gas forcing is a key driver of inter-model uncertainties. While all models project an AMOC decline, the inter-model spread in the decline rate drives very different climate change impacts, including temperature, precipitation, and large-scale atmospheric circulation patterns. Here we investigate the impacts of a weakened AMOC by performing idealized climate model experiments using EC-Earth3, a state-of-the-art GCM participating in CMIP6. We compare results from a control experiment run under preindustrial forcing, with an experiment in which we force a weakened AMOC by applying a virtual salinity flux in the North Atlantic/Arctic basin. Here we analyze previously unexplored aspects of the climate response to a weakened AMOC, focusing on impacts on wintertime daily timescales in the Euro-Atlantic region.We find that a weakened AMOC forces an overall drier climate over most of Europe; however, some regions especially in northwestern Europe experience an increase in the number of very wet days. We investigate drivers of precipitation changes by performing a moisture budget and analyzing the association with changes in weather regimes at daily timescales. We find that an increase in the occurrence of the NAO+ days (going from a frequency of ~26% of occurrence to above 42%) together with an enhanced and more central jet, favors drier conditions over southern Europe and wetter conditions over northwestern Europe. Further, enhanced but drier storms cause dryness over Europe while thermodynamic processes per se, namely the Clausius-Clapeyron constraint on temperature, play a second role. Finally, we explore these relationships in additional experiments in which we keep the AMOC constant in a forced 4xCO2 experiment by applying a reversed virtual salinity flux, which allows us to separate the effects of 4xCO2 forcing from the weakened AMOC on climate change impacts. Our results have broader implications for understanding the role of the AMOC response on future climate change, allowing us to separate the impacts of the AMOC from those of the CO2 increase.
Two out of three ain’t bad: Dealing with proxy paucity when correlating the base of the Cambrian
Authors: Topper Timothy , Betts Marissa , Dorjnamjaaa Dorj , Li Guoxiang , Li Luoyang , Altanshagai Gundsambuu , Enhkbaatar Baktuyag , Skovsted Christian
Published: February 2023

Global Boundary Stratotype Section and Points (GSSP’s) are often regarded as immutable points, that once ratified should “remain fixed in spite of discoveries stratigraphically above and/or below” (Cowie, 1986, p. 79). The Precambrian–Cambrian boundary, defined at Fortune Head by the FAD of the trace fossil Treptichnus pedum, has been a source of controversy and debate since its ratification. Treptichnus pedum has proven to be a difficult marker to apply to global correlation, and lack of other markers at Fortune Head (skeletal fossils, chemostratigraphic, magnetostratigraphic or radiometric data) has prompted the use of other “unofficial” indicators of the Precambrian–Cambrian boundary in many sections around the world. δ13C chemostratigraphy has become a standard global correlation tool, and the integration of δ13C isotopes with other “multi-proxy” data is an approach that is becoming increasingly adopted. Discoveries and advances in such methods and techniques demonstrate that new data can (and should) enable the fine-tuning of stratigraphic boundaries. Recent work in southwestern Mongolia through the Precambrian–Cambrian boundary section at Bayan Gol demonstrates the utility of multi-proxy stratigraphic data to defining and correlating the base of the Cambrian. Here, two proxies are used in concert to identify the Precambrian–Cambrian boundary; the first occurrence of the small shelly fossil Protohertzina anabarica and the nadir of the BACE (δ13C excursion). This section demonstrates 1) the value of carbonates in their capacity to preserve a wider variety of stratigraphic proxies than siliciclastics, 2) the importance of systematically measured and sampled stratigraphic sections (rather than composite sections) for regional and global correlation and 3) the need for a redefined Cambrian GSSP, with a supporting ASSP as a pathway toward global correlation of the base of the Cambrian.
Droplet dynamics in homogeneous and isotropic turbulence
Authors: Chibbaro Sergio , Crialesi-Esposito Marco , Brandt Luca
Published: February 2023

Emulsions are a major class of multiphase flows, crucial in industrial process (e.g. food and drug production) and ubiquitous in environmental flows (e.g. oil spilling in maritime environment). Already at volume fractions of few precents, the dispersed phase interacts with pre-existing turbulence created at large scale, yet the interaction between phases and the turbulent energy transport across scales is not yet fully understood.In this work, we use Direct Numerical Simulation to study emulsions in homogeneous and isotropic turbulence, where the Volume of Fluid (VoF) method is used to represent the complex features of the liquid-liquid interface.We consider a mixture of two matching-density phases, where we vary volume fraction, viscosity ratio and large-scale Weber number aiming at understanding the turbulence modulation and the observed droplet size distributions.  The analysis, based on the spectral scale-by-scale analysis, reveals that energy is consistently transported from large to small scales by the interface, and no inverse cascade is observed. We find that the total surface is directly proportional to the amount of energy transported, and that the energy transfer in the inertial range provides information about the droplet dynamics. We observe the -10/3 and -3/2 scaling on droplet size distributions, suggesting that the dimensional arguments which led to their derivation are verified in HIT conditions and denser conditions. Finally, we discuss the highly intermittent behaviour of the multiphase flow, which can be directly related to the polydisperse nature of the flow.The study provides some significant observations towards a more comprehensive understanding of multiphase turbulence, opening new questions for future studies. 
Tracking Clouds: Comparing Geostationary Satellite Observations and Model Data
Authors: Müller Felix , Seelig Torsten , Tesche Matthias
Published: February 2023

Tracking clouds has multiple applications. It is used for short-term weather forecasting as well as long-term weather and climate analyses. Our long-term goal is to investigate cloud life cycles under different conditions, such as marine or continental areas, over deserts, or in areas with increased anthropogenic aerosols. This is a key element in understanding cloud radiation effects and the human influence on the cloud life cycle.To identify clouds and their trajectories, we are using Particle Image Velocimetry [1] which is well-known for measuring velocities in fluid dynamics. These velocity fields are used to predict the positions of clouds in the next timestep. The predicted positions are then compared to the observed positions to match clouds across timesteps. The algorithm can work on any geostationary satellite data set or equivalent model data [2].Currently we are comparing satellite data from the EUREC4A campaign [3] (observed by the Advanced Baseline Image onboard the GOES-16 satellite) and model output from ICON-LEM [4]. Both datasets are located east of Barbados in the Caribbean Sea. This is done to benchmark the model settings and to identify which of the three model resolution best captures the satellite data. The cloud tracking allows us to look at the lifetimes of the clouds and the development of cloud physical properties over the lifetime of a cloud. This leads to a more refined investigation into the cloud behavior.The presented results are twofold. Firstly, we will show a direct comparison of individual cloud trajectories between observed and model data to establish a deeper understanding of the methodology and datasets. Secondly, we will look at the distributions of clouds sizes and lifetimes to compare different resolutions of model data to the observed satellite data. References:[1] Raffel et al. (2007) "Particle Image Velocimetry - A Practical Guide", Springer Verlag, doi: 10.1007/978-3-540-72308-0[2] Seelig et al. (2021) "Life cycle of shallow marine cumulus clouds from geostationary satellite observations", in JGR: Atmospheres, doi: 10.1029/2021JD035577[3] EUREC4A campaign: www.eurec4a.eu[4] Dipankar et al. (2015) “Large eddy simulation using the general circulation model ICON”, in Journal of Advances in Modeling Earth Systems 7(3): 963-986, doi: 10.1002/2015MS00043
Planktonic and benthic foraminifera assemblages from Fantangisña serpentinite mud volcano in the NW Pacific Ocean during the Pleistocene (IODP Expedition 366)
Authors: Del Gaudio Arianna Valentina , Piller Werner E. , Auer Gerald , Kurz Walter
Published: February 2023

The Mariana forearc constitutes the southern sector of the Izu-Bonin-Mariana (IBM) trench-arc system (12° N to 35° N) in the NW Pacific Ocean. It is the only setting where active serpentinite mud volcanism is recorded.The Mariana forearc hosts several large serpentinite mud volcanoes, among which Fantangisña seamount was cored during International Ocean Discovery Program (IODP) Expedition 366. Lithologies comprise pelagic sediments covering serpentinite mud deposits with ultramafic clasts which derive from the subducting Pacific Plate, forearc crust and mantle. In addition, nannofossil-bearing pelagic sediments and volcanic ash/tephra layers were found at the bottom of the core.Fantangisña seamount is located in the tropical Pacific region, at low latitudes (16° N) within the latitudinal band of the North Equatorial Current (NEC). The NEC is a warm and nutrient- poor water mass, flowing westward in the tropical Pacific Ocean, driven by trade winds.In this study, benthic and planktonic foraminifera analyses were performed at Site U1498A, located on the southern flank of Fantangisña serpentinite mud volcano. Most of our analysed interval covers the Early to Late Pleistocene as indicated by previous biostratigraphic investigation on this site. Cluster analyses on Pleistocene planktonic foraminifera resulted in two major clusters based on thermocline-dwelling species (e.g., Globorotalia spp.) to mixed-layer dwellers (e.g., G. ruber, G. rubescens, G. glutinata, Trilobatus spp.) ratio, which infer variations of the depth of the thermocline (DOT) during the Pleistocene. These changes of the DOT can be related to fluctuations in the intensity of the NEC. Our data implies a deep and stable thermocline with an intense NEC during the interval of the Early-Middle Pleistocene Transition (EMPT). In contrast, both thermocline and NEC weakened during the Middle-Late Pleistocene, following the EMPT. Variations in strength of the NEC could be associated with ENSO climate conditions (El Niño/La Niña).Planktonic foraminifera diversity suggests that the distribution of planktonic assemblages was not affected by the serpentinite mud activity in the area. In addition, our results imply that the preservation of the planktonic tests could be enhanced by rapid burial under the serpentinite mud flows.High diversity (99 taxa) was recorded for benthic foraminifera before and after the serpentinite mud flow volcanism indicating oligotrophic and well-oxygenated bottom-water conditions. In contrast, benthic species were severely affected by the volcanic activity due to serpentinite mud flows and gas emissions. 
Use of high spatial resolution nitrogen attenuation mapping in groundwater and surface waters for planning how to reach nitrogen reduction goals in 3rd River Basin Management Plans: Hjarbæk coastal catchment, Denmark
Authors: Windolf Jørgen , Tornbjerg Henrik , Larsen Søren , Kronvang Brian
Published: February 2023

The requirements under the present River Basin Management Plans (RBMP) for the EU Water Framework Directive (WFD) are to reduce the total nitrogen (TN) loadings to the Hjarbæk Estuary in Denmark from the present (2015-2019) annual loading of 1900 tonnes N to 662 tonnes N in 2027. The catchment area to the estuary represents a total of 1177 km2 and the catchment is drained by four major streams. The Danish national monitoring programme has established gauging stations covering 969 km2 of the catchment area the remaining 208 km2 being ungauged areas. Modelled data on N-leaching from the root zone on agricultural fields and surface water monitoring data on N-export losses are available from the 1980’ies and onward.A detailed mapping of nitrogen (N) attenuation in the catchment have been conducted at a scale of ca. 15 km2 (ID15 sub-catchments) including mapping of both N-retention in groundwater and surface waters as well as N-delays in groundwater in Karst sub-catchments. The mapping shows large differences in N-retention in groundwater within the ID15 sub-catchment (<20 % to >80 %) and the same large variation is seen for N-retention in surface waters (<20 % to >80 %). An analysis of delays in the transport for N from fields to surface waters have shown that especially one of the four monitored catchments (Simested stream) experiences a long delay in N repsonses (> 10 years).  A new portfolio of N mitigation measures to be adopted at source (e.g. catch crops, early seeding, set a side, afforestation) or during transport from field to surface water (several types of constructed wetlands, riparian buffers and restored wetlands) has been scientifically approved and made available for farmers by the Danish EPA and Agricultural Agency.The huge N-reduction needed in the Hjarbæk coastal catchment (65%) will require management efforts where farmers and authorities utilize both source oriented and transport oriented mitigation measures. These solutions should be implemented in a targeted manner guided by the local N-retention maps, as well as using all available monitoring data to pinpoint high-risk areas for N-leaching from fields and N-exports from the four sub-catchments as well as the ungauged areas. In this presentation we will showcase examples on how both targeted and collective mitigation measures can optimally be dosed in the Hjarbæk coastal catchment to reach the targets set in the RBMP 3.   
Forms and evolution of plate tectonics on the Archean Earth
Authors: Kuang Jian , Morra Gabriele , Yuen Dave , Qi Shihua
Published: February 2023

It is hotly debated when plate tectonics began to operate on the earth, believed to happen sometime during the Archean. We study here the relationship between metamorphism and drip and plate tectonics during the Archean. We examined metamorphic proxy, and tracked tectonic forms and processes over the Archean by synthesizing (i) zircon U-Pb age spectra and isotopes of samarium and neodymium, (ii) compiling events associated with continental crustal growth and reworking, and (iii) integrating various proxies connected to plate tectonics and special magmatism/tectonics. We propose that plate tectonics started at the latest in the Eoarchean and occurred in the form of accretion or collision without subduction around 3.7 billion years ago (Ga); suggest that 3.3-3.1 Ga and 3.0-2.9 Ga were the time of local subduction initiation and the onset of the global plate tectonics, respectively; confirm the assembly of Kenorland supercontinent at 2.8-2.5 Ga. We finally established a secular evolution model to visualize the evolution of Archean plate tectonics from stagnant to local, regional, and global scales.
Fostering geoheritage in volcanic risk areas: the case of the Calbuco volcano, Southern Chile.
Authors: Sanchez Florencia , Pereira Paulo , Romero Jorge , Schilling Manuel
Published: February 2023

Calbuco Volcano (41.3°S, 72,6ºW) is located in the Southern Andes of Chile, in the Los Lagos region. It ranks 3rd in the Chilean volcanic risk ranking (www.sernageomin.cl) having both high hazard due to recent and frequent eruptions and exposure to that hazard of about 300 000 people in the region. Its last eruption (April 22-23, 2015), severely affected the surroundings of the volcano, including the village of Ensenada, evidencing a growing need for volcanic risk reduction. This task can be assisted by raising awareness of volcanic processes and geoheritage, contributing to reduce exposure to hazards, and to risk education and mitigation. In this work, an assessment of the geoheritage potential of the northern flank of the Calbuco Volcano is presented. Literature review, geological mapping, stratigraphy, and petrographic studies of some recent deposits and eruptive products were performed. Volcanic deposits and landforms (e.g., pyroclastic density currents, lahars, tephra falls, and lava flows) is key to reconstructing volcanic eruptions and providing volcanic hazard data. Besides, well-preserved, and easily accessible eruptive sequences can be used to educate communities exposed to volcanic hazard through different outreach and geoeducation techniques which can help volcanic risk mitigation. The identified geosites were numerically assessed, scoring through qualitative and quantitative procedures. The top-five ranked geosites have high scientific value and use potential, allowing the observation of volcanic processes under better accessibility conditions. They may offer scientific, educational, and touristic use if geoconservation strategies are considered in the management of the areas around the volcano. Part of the volcanic edifice remains inside parks, both public (Llanquihue National Reserve) and private (Parque Valle los Ulmos and Parque Volcanes), which gives it greater accessibility and conservation potential. The addition of further geosites to the inventory from other flanks of the volcano is aimed, for a more detailed characterization of the area and the support of geoconservation strategies and volcanic risk reduction. With these studies, more scientific knowledge and awareness of volcanic processes and hazards can be achieved, mainly to benefit the social and economic development of local population. A geopark project in the area would be an incentive to that development and a way to educate the population about geodiversity, geoheritage and volcanic hazards topics. This type of strategy would have to include local institutions in its management, such as local government bodies, universities and research units, nature conservation staff and local associations to be a nationally and internationally recognized project. Key words: Calbuco volcano, Southern Andes, volcanic risk, geoheritage, education.
Application of multimodal deep learning using radar and water level data for water level prediction
Authors: Yoon Seongsim , Kim Seyong , Bae Sangmin
Published: February 2023

In general, water level prediction models using deep learning techniques have been developed using time-series water level observation data from upstream water level stations and target water level stations even though many of physical data are necessary to predict water level. The changes of the water level are greatly affected by rainfall in the basin, therefore rainfall information is needed to more accurately predict the water level. In particular, radar data has the advantage of being able to directly acquire the amount of rainfall occurring within a watershed. This study aims to develop the multimodal deep learning model to predict the water level using 2D grid radar rainfall data and 1D time-series water level observation data. This study proposed two multimodal deep learning models which have different structures. Both multimodal deep learning models predict the water level by simultaneously using the observed water level data up to the present time and the radar rainfall data that affects the water level in the future. The first proposed model consists of a deep learning network that links 2D Average Pooling (AvgPool2D), which compresses 2D radar data to 1D data, and Long Short-Term Memory (LSTM), which predicts 1D time series water level data. The second proposed model consists of a deep learning network that predicts water levels by linking Conv2DLSTM and LSTM, which can reflect the characteristics of 2D radar data without deformation.  The two proposed multimodal deep learning models were learned and evaluated in the upper basin of Hantan River. In addition, it was compared with the results of single-modal LSTM using only water level data. There are three water level stations in the study area, and the objective was to predict the water level of the downstream station up to 180 minutes in advance. For learning and verification of the deep learning model, 10-minute water level and radar rainfall data were collected from May 2019 to October 2021. For the radar data used as input, the grid data included in the target watershed were extracted and used among composite radar data with a resolution of 1 km operating by Ministry of Environment. As a result of evaluating each learned deep learning model, two multimodal models had higher prediction accuracy than the single-modal using only water level data. In particular, second proposed model (Conv2dLSTM+LSTM) had better predictive performance than first proposed model (AvgPool2D+LSTM) at the time of the sudden rise in water level due to rainfall.AcknowledgmentsResearch for this paper was carried out under the KICT Research Program (project no. 202200175-001, Development of future-leading technologies solving water crisis against to water disasters affected by climate change) funded by the Ministry of Science and ICT.
Processes driving the speedup of Pine Island Ice Shelf between 2017 and 202
Authors: Sun Sainan , Gudmundsson Gudmundur Hilmar
Published: February 2023

From 2017 to 2020, three significant calving events took place on Pine Island Glacier, West Antarctica. Ice-shelf velocities changed over this period and the calving events have been suggested as possible drivers. However, satellite observations also show significant changes in the areal extent of fracture zones, especially in the marginal areas responsible for providing lateral support to the ice shelf. Here we conduct a model study to identify and quantify drivers of recent ice-flow changes of the Pine Island Ice Shelf. In agreement with recent studies, we find that the calving events caused significant velocity changes over the ice shelf. However, calving alone cannot explain observed velocity changes. Changes in the structural rigidity, i.e., ice damage, further significantly impacted ice flow. We suggest that ice damage evolution of the ice-shelf margins may have influenced recent calving events, and these two processes are linked.
Development of a high-finesse broadband optical cavity using prism based on total internal reflection for applied spectroscopy
Authors: Cui Ruyue , Wang Gaoxuan , Yalin Azer , Meng Lingshuo , Coeur Cécile , Dong Lei , Chen Weidong
Published: February 2023

The use of high reflectivity dielectric mirrors to form a high finesse optical cavity allows one to achieve long optical path lengths of up to several kilometres for high-sensitivity spectroscopy applications [1,2]. The high reflectivity of a dielectric mirror is achieved via constructive interference of the Fresnel reflection at the interfaces produced by multilayer coatings of alternate high and low refractive index materials [3]. This wavelength-dependent coating limits the bandwidth of the mirror's high reflectivity to only a few percent of the designed central wavelength.We report on the recent development of a novel optical cavity based on prisms as cavity reflectors [4-6], which offers a high-finesse optical cavity operating in a broadband spectral region from 400 to more than 1600 nm [7] and provides a very suitable high-sensitivity spectroscopic technique for frequency-comb application. Acknowledgments : This work is supported by the French national research agency (ANR) under the MABCaM (ANR-16-CE04-0009), the CaPPA (ANR-10-LABX-005), the ICAR-HO2 (ANR-20-CE04-0003) contracts, and the regional ECRIN program. References[1] S. S. Brown, Chem. Rev. 103 (2003) 5219-5238.[2] M. Mazurenka, A. J. Orr-Ewing, R. Peverallb and G. A. D. Ritchie, Annu. Rep. Prog. Chem. Sect. C101 (2005) 100-142.[3] G.R. Fowles, Introduction to Modern Optics, 2nd ed. (Rinehart and Winston, 1975), p. 328.[4] H. Moosmuller, App. Opt. 37 (1998) 8140-8141.[5] P. S. Johnston and K. K. Lehmann, Opt. Express 16 (2008) 15013-15023.[6] B. Lee, K. Lehmann, J. Taylor and A. Yalin, Opt. Express 22 (2014) 11583-11591.[7] G. Wang, A. Yalin, C. Coeur, S. Crumeyrolle, R. Akiki, E. Fertein, W. Chen, 6th International Workshop on Infrared Technologies, October 29-30, 2019, Princeton, New Jersey, USA.
Holocene oceanographic variability linked to the Guinea Dome development recorded in a deep-sea sediment core off Cabo Verde
Authors: Pérez-Rodríguez Irene , Hansteen Thor H. , Schindlbeck-Belo Julie C. , Nürnberg Dirk , Kutterolf Steffen , Huvenne Veerle A.I. , Barnhill Kelsey Archer , Simon-Lledó Erik , Evans Susan , Vinha Beatriz , Mosquera Giménez Ángela , Orejas Covadonga
Published: February 2023

The Guinea Dome, located in the eastern tropical North Atlantic, is produced by cyclonic circulation associated with the eastward North Equatorial Countercurrent, the northward Mauritanian Current and the westward North Equatorial Current, which causes the uplift of the isotherms in the Guinea Dome. This oceanographic feature is important for the regional atmosphere-ocean dynamics, and its variability was suggested to be linked with precipitation changes in North Africa, at least at a decadal scale. Characterizing the development of the dome through the Holocene will contribute to understand the prominent environmental changes that occurred regionally during this period, as evidenced by the green-to-desert Sahara transition at the end of the African Humid Period (ca. 6,000 years ago).A 35cm sediment multicore, extracted southwest off Cabo Verde during the iMirabilis2 scientific cruise, at a water depth of 4,394 m, is being investigated. We present planktonic foraminifera counts and X-ray fluorescence (XRF) scanning data to reconstruct palaeoceanographic and sediment input changes during the Holocene. An age-depth model for the sediment core was established with three samples dated by the radiocarbon method, indicating that the sediment was deposited from 11,180 to 1,257 calibrated years before present (cal. BP).Planktonic foraminifera results show a gradual but important change in the assemblages throughout the core, where the abundance of species preferring warmer waters increase by 44% towards the top of the core. These results are interpreted as warming of the surface water masses during the Holocene, as a result of reduced influence of the Guinea Dome due to its change of location to a more southern position and/or as a consequence of a weakening of the dome. X-ray fluorescence scan variations along the core show that the faunal shift is encompassed by differences in the terrigenous sediment supply, indicating changes in the inland climate regime. For instance, changes in the Ti/Fe, Ti/Al and Al/Ca ratios are proxies for the fluvial/aeolian sedimentary input and the hinterland climate variability. An increase of the high river discharge indicators is displayed between 10 and 6 kyr BP, probably as a consequence of the increased precipitation that took place during the African Humid Period.Further ongoing geochemical analyses of foraminifera shells will provide information regarding the temperature, salinity and productivity of both, the mixed layer and the sub-thermocline, which will improve the characterization of the variability that the Guinea Dome experienced during the Holocene.
Generating weather symbol data in IMPROVER
Authors: Moseley Stephen , Ayliffe Ben , Evans Gavin
Published: February 2023

The UK Met Office is developing an open-source probability-based post-processing system called IMPROVER (Integrated Model Post-Processing and Verification) to fully exploit our convection permitting, hourly cycling ensemble forecasts.  Post-processed MOGREPS-UK model forecasts are blended with deterministic UKV model forecasts and data from the coarser resolution global ensemble, MOGREPS-G, to produce seamless probabilistic forecasts from now out to 7 days ahead. For precipitation, an extrapolation nowcast is also blended in at the start.A majority of the post-processing within IMPROVER is performed on gridded forecasts, with site-specific forecasts extracted as a final step, helping to ensure consistency. IMPROVER delivers a wide range of probabilistic products to both operational meteorologists and as input to automated forecast production. The system achieved operational acceptance in spring 2022 and will be used in operational products from spring 2023.Weather symbols provide the general public with a simple, pictorial view of the weather for a time of interest and include sun and cloud conditions, mist and fog, hail and lightning, and three phases of precipitation, both as showers or continuous, and light or heavy. This talk describes how a deterministic most-likely weather type code is generated using a decision tree approach from probabilistic multi model IMPROVER data for 1 hour, 3 hour and daytime periods that are consistent with each other. Recent work to make these weather codes representative of a time-window, rather than an instant, will be discussed. We will present some verification, comparing IMPROVER weather symbols and the current operational Met Office symbols with SYNOP present weather reports.