bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Solar Radiation in Forests Using Drone LiDAR Data in Japanese Artificial Forests
Authors: Takamura Shiori , Onda Yuichi , Zhang Yupan , Hashimoto Asahi , Kato Hiroaki , Gomi Takashi , Chiu Chenwei
Published: February 2023

Many Japanese cypress plantation forests have been degraded due to inadequate forest management, resulting in low solar radiation on the forest floor. In recent years to increase forest floor radiation, however, assessment methods for the impact of thinning have not been developed.　The light environment in forests has been estimated by Hemispheric photography with a fisheye lens camera and using image analysis software Hemisfer to determine the amount of solar radiation in the forest and canopy openness situation. To precisely recreate the actual canopy structure, it is challenging due to the limitations of fisheye lenses, which cause distortions as the distance from the center of the captured area grows and the projected area decreases. In addition, taking Hemispherical photos in the forest is labor and time intensive work.In this study, to explore the forest light environment in cypress plantations, we not only performed image analysis of hemispheric photography, but also estimated forest solar radiation using drone LiDAR data. The study site was a cypress plantation forest located in Mt.Karasawa, Sano City, Tochigi Prefecture. The site is a south-facing slope with a slope angle of approximately 30 degrees. 25 pyranometers were set up in the forest in a grid pattern with 1-meter intervals to measure the spatial distribution of solar radiation in the forest. Total solar radiation was measured by a radiometer installed outside the forest. For Hemispherical image analysis, the software Hemisfer was used to calculate direct and diffused solar radiation in the forest. The drone generated high-density point cloud data with a point cloud density of 2000 pts/m2 was converted to 1cm3 voxel data first, then canopy openness was calculated by clipping the area directly above each pyranometer into a cylindrical buffer and calculating the percentage of the total number to the canopy points number. Considering the significant effect of direct sunlight in forest solar radiation, we varied the solar height in 5° intervals to simulate the actual angle of sunlight penetrating the tree canopy and recalculated the openness.While the Hemispheric photography did not capture the detailed solar radiation changes in the measured data, the UAV LIDAR data succeeded in reproducing solar radiation changes closer to the measured data by considering the canopy openness. Therefore, there is a possibility of more accurate estimation by using LiDAR data together.
A new brittle rheology and numerical framework for large-scale sea-ice models
Authors: Ólason Einar , Boutin Guillaume , Korosov Anton , Rampal Pierre , Williams Timothy , Kimmritz Madlen , Dansereau Véronique , Samaké Abdoulaye
Published: February 2023

We present a new brittle rheology and an accompanying numerical framework for large-scale sea-ice modelling. We have based this rheology on a Bingham-Maxwell constitutive model and the Maxwell-Elasto-Brittle (MEB) rheology for sea ice. The key strength of the MEB rheology is its ability to represent the scaling properties of simulated sea-ice deformation in space and time. The new rheology we propose here, which we refer to as the brittle Bingham-Maxwell rheology (BBM), represents a further evolution of the MEB rheology. We developed BBM to address two main shortcomings of the MEB rheology and numerical implementation: excessive thickening of the ice in model runs longer than about one winter and a relatively high computational cost. The BBM addresses these shortcomings by demanding that the ice deforms under convergence in a purely elastic manner when internal stresses lie below a given compressive threshold. It also improves numerical performance by introducing an explicit scheme to solve the ice momentum equation. We show that using an implementation of BBM in the neXtSIM sea-ice model, the model gives reasonable long-term evolution of the Arctic sea-ice cover. It also gives very good deformation fields and statistics compared to satellite observations.
Bed level variation and channel sensitivity analysis of a river channel to the extreme flood event
Authors: Bind Vivek Kumar , Jain Vikrant
Published: February 2023

Sediment transport is a fundamental process to understand river morphodynamics. Bedload sediment transport during high flow energy governs channel geometry, though with variable response to flood events. Therefore, the sensitivity of bedload sediment transport to flood events is an important geomorphic query. We analysed the bedload transport process during the extreme flood event in the Purna River, a partial-bedrock river in peninsular India. The Purna River originates from an elevation of ~900 m and drains ~18,450 km2 area. This major tributary of the Tapi River flows ~360 km. The flood events were characterised through flood frequency analysis using the Gumble distribution on peak discharge data from 1980-2016. The bedload sediment transport was assessed for the highest flood event using the Mayer-Peter Muller equation. Daily data of discharge, wetted area, wetted perimeter, grain size (D50) data of pre- and post-monsoon, and the cross-section was obtained from the Central Water Commission (CWC), India. The bed slope was analysed using Manning’s equation. Our analysis shows that the return period for the highest flood at upstream station (Gopalkheda) is 35 years, while it is 136 years for downstream station (Yerly). The average bed shear stress was ~1.04 and ~1.55 times more than the critical shear stress using D50 during the flood event for upstream and downstream reaches, respectively. The average bed shear stress exceeded the equal mobility condition (τeq≈1.45τc) in the downstream reach leading to full mobilisation. Therefore, it causes high bedload transport and scouring of bed level by more than 1 m in the downstream reach. However, at upstream reach, there was low bedload sediment transport and insignificant change in the bed level due to partial mobilisation. Also, the Maximum Flow Efficiency (MFE) at the downstream station is 6-7 times more than the upstream reach, representing high erosion in the downstream reach. Therefore, Purna River is characterised by reach-scale variability in the channel process to the same flood event. The downstream reach is more sensitive than the upstream reach and hence more prone to morphological change. These alterations have implications for designing hydraulic structures, water management, and river ecology.
InSAR observations of syn-seismic slip on faults due to M~6 earthquakes
Authors: Sudhaus Henriette , Begg John , Mouslopoulou Vasiliki , Knüppel Julia , May Tilman
Published: February 2023

As well as slip on a primary fault plane, earthquakes can produce slip on neighbouring faults which are not directly linked to the main source. This slip is called syn-seismic. With modern space-borne observation techniques, we observe syn-seismic slip down to a few centimeters on active faults nearby the source. An excellent example is the mapped slip on secondary faults during the 2019 Ridgecrest earthquake sequence in California. The overall spatial pattern of syn-seismic slip with respect to the main fault suggest that these faults respond to local stress changes caused by the main shock.Data that enable the detection of surface fault slip on such small scale are provided by optical and radar satellites which allow a very high precision with high spatial resolution. In particular, short revisit times of these satellite observations lead to high coherence between images matched in pixel-offset and radar interferometric techniques.We present further examples of syn-seismic fault slip during ~M6 earthquakes from different regions, such as those recorded in Greece in 2021 (Tyrnavos and Arkalochori) and 2020 in Tibet (W Xizang and near Xegar). We use Sentinel-1 interferometric wide-swath SAR acquisitions, which we process on the highest spatial resolution and apply weak filtering only. Our examples have in common that their syn-seismic fault activation reveals slip of a few centimeters only, persistently along a section of the fault’s length. The slip directions commonly appear to follow the coseismic surface displacement gradients which, in some cases, results in reverse slip on long-term normal faults. The activated faults were either faults previously mapped or concealed faults which were identified due to InSAR.It is difficult to estimate the depth of syn-seismic fault slip and therefore how much strain has been released due to localized stress changes. We are also uncertain of the extent to which this small slip release contributes to the long-term displacement and displacement rate on faults and whether its contribution should be included in dislocation fault slip models. Our compilation suggests that syn-seismic slip is rather common, despite the rarity of previous observations, and is now detectable only because of improved resolution provided by InSAR data.
A Toarcian Oceanic Anoxic Event record from an open-ocean setting in the northern margin of eastern Tethys: Implications for redox and weathering conditions
Authors: Nie Ying , Fu Xiugen
Published: February 2023

The Toarcian Oceanic Anoxic Event (T-OAE, ~ 183 Ma), also known as Jenkyns Event, was one of the most important hyperthermal events of the Mesozoic, marked by a prominent negative carbon-isotope excursion (CIE) in both terrestrial and marine material. Although the T-OAE has been widely studied in the western Tethyan and Boreal regions, only relatively few investigations about the T-OAE have been conducted in other sites. Here we present new carbon-isotope, element geochemical and sedimentological data from a lower Toarcian open-marine section in the northern margin of eastern Tethys (Qiangtang Basin). This study section shows a negative CIE, which accords with other well-preserved sedimentary successions, and thus our data provide the evidence of the T-OAE from an open-marine setting in the northern margin of eastern Tethys. Elemental, mineralogical and sedimentological data indicate that mainly oxic bottom water conditions prevailed during the T-OAE interval in the section. Therefore, anoxia is not a significant feature of the T-OAE in the study area. Combined with previous studies, redox conditions in the bottom water show a clearly spatially variable and mainly depend on local conditions (e.g., water depth and basin hydrography). Sedimentological and geochemical analyses reveal an intensified chemical weathering and an increased coarse-grained detrital flux during the T-OAE, which is a regional response to global warming occurring in this interval.
Validation of high resolution remotely sensed and modeled snow cover with webcam imagery
Authors: Kollert Andreas , Mayr Andreas , Rutzinger Martin , Dullinger Stefan
Published: February 2023

Recently, snow cover has gained a lot of interest as an important driver of plant species distribution in arctic and alpine environments, especially on small spatial scales . However, variation of snow cover at this scale is hardly resolved by open satellite data. Hence, linking remotely sensed snow cover and critical patterns and processes in vegetation can be challenging due to a mismatch in spatial resolution.
We present a study based on a high alpine network of three webcams for the validation of snow cover products covering an entire year. Satellite based snow cover products (Landsat, Sentinel-2, downscaled MODIS products) are benchmarked on webcam-derived snow cover. While optical satellite remote sensing is a valuable tool for characterizing snow cover dynamics at the scale of tens of meters, cloud cover causes considerable data gaps. As a temporally and spatially more continuous estimate, we additionally produce meter-scale snow cover using the openAmundsen model, and we compare this to the webcam derived snow cover as well. For all datasets, ecologically relevant indicators like snow cover duration and the number of snow-free days are aggregated and validated both for the entire year and on a sub-seasonal scale.
Impact of incremental analysis update initialization under the replay configuration on forecasts of a squall line event in southern China
Authors: gao yanqing , wang xiaofeng
Published: February 2023

A squall line system that occurred on 9-10 April 2016 over southern China was used to investigate the impact of incremental analysis update (IAU) initialization under the replay configuration on its forecasts. The ERA5 global reanalysis and the forecast field of the regional Weather Research and Forecasting (WRF) Model were used to construct the analysis increment. The results showed that IAU initialization reduced the imbalance caused by the introduction of the low-resolution global reanalysis into the high-resolution regional WRF model and retained the microphysical information in the forecast field of the regional WRF model, which reduced the spin-up time. Compared with the cold start run initialized directly by the ERA5 reanalysis, the linear structure and precipitation distribution of the squall line system using IAU initialization were closer to those in the observations. Further analyses indicated that the improvement of the squall line forecasts using IAU initialization was mainly related to the faster development of cold pool caused by retaining the microphysical information in the forecast field of the regional WRF model and the more favorable stratification conditions corrected by the IAU increment.
Analyzing the development of cold air outbreaks and warm air intrusions based on remote sensing and dropsonde data from (AC)3 campaigns
Authors: Klingebiel Marcus , Monrad-Krohn Lukas , Kirbus Benjamin , Mech Mario , Ehrlich André , Wendisch Manfred
Published: February 2023

Within the framework of (AC)3, four airborne campaigns were conducted in the vicinity of Svalbard to investigate the Arctic airmass transformations during warm air intrusions (WAI) and marine cold air outbreaks (CAO). In this study, we will take a deeper look into the development process of CAOs starting from the marginal sea-ice zone towards the open ocean, using data from active and passive remote sensing instruments. In addition, we will present data from more than 450 dropsondes launched during the HALO-(AC)3 campaign and analyze the development of the vertical profiles along WAIs and CAOs. This is done by using a Lagrangian analysis of the campaign, which delivers same-day and next-day trajectory matches of the HALO flights.
Soil structure changes of constructed soil in bioretention cell during three years
Authors: Heckova Petra , Snehota Michal , Koestel John , Klement Ales , Kodesova Radka
Published: February 2023

Constructed soils play an important role in urban hydrology e.g. in the functioning of green roofs and stormwater bioretention cells. Water infiltration, colloid transport, and heat transport are affected by changes in pore system geometry particularly due to the development of macropores and clogging by particles. The aim is to elucidate changes in bioretention cell performance by studying the structural changes of soils at the microscale by invasive and noninvasive methods. Noninvasive visualization methods such as computed microtomography (CT), are an effective mean of soil structure assessment. X-ray CT is capable to investigate soil in terms of structure development, pore-clogging and pore geometry deformations.Two identical bioretention cells were established in December 2017. The first bioretention cell (BC1) collects the stormwater from the roof of the nearby experimental building (roof area 38 m2). The second bioretention cell BC2 is supplied from a tank using a controlled pump system for simulating artificial rainfall. Each BC is 2.4 m wide and 4.0 m long. The 30 cm thick biofilter soil mixture is composed of 50% sand, 30% compost, and 20% topsoil. Bioretention cells are isolated from the surrounding soil by a waterproof membrane. The regular soil sampling program was initiated in 2018 in order to visualize and quantify the soil structure and internal pore geometry of samples. Undistributed samples were collected from the surface of the filter layer twice a year from each BC. The aluminum sampling cylinders had an internal diameter and height of 29 mm. Three batches of samples were taken during three years. The first set of 24 undisturbed samples was collected upon planting in June 2018, while the second set of 24 samples was taken after the end of the first vegetation period in November 2018. The second batch of 48 samples, were taken in the same period as in the previous year.  The last batch of 24 samples was taken in June 2020. Those collected samples were scanned by CT imaging.Analyses of pore network morphologies were performed on the scanned samples. Macroporosity, pore thickness, pore connection probability, critical diameter and Euler-Poincare density were determined to understand pore space in the biofilter. Macroporosity in BC1 shows a decreasing trend in the first three periods, it can be a result of soil consolidation. In subsequent periods, macroporosity remains constant in BC1. The characteristic pore connection probability in BC1 also shows a decreasing trend in the first three periods, but compared to the macroporosity, the connectivity increases in the last two periods in BC1. This may be due to plants growth, which was most pronounced in 2019. The samples' most frequently represented pore thickness ranges from 80 to 330 µm in all periods in both BCs. The percentage of these pores was higher than 50% in both BCs.
An extended N cycle in the eddy-permitting global ocean model ICON-O
Authors: Hülse Dominik , Six Katharina , Burt Daniel , Chegini Fatemeh , Ramme Lennart , Ilyina Tatiana
Published: February 2023

Nitrogen (N) plays a central role in marine biogeochemistry by regulating biological productivity, influencing the cycles of carbon, oxygen, and other nutrients, and controlling oceanic emissions of the potent greenhouse gas nitrous oxide (N2O). Although the marine N cycle consists of multiple chemical species, global biogeochemical models often employ simple parameterizations of N transformations and omit key tracers and processes. Here we present an extended numerical representation of the marine N cycle that includes explicit tracers for nitrate, dinitrogen, nitrous oxide, ammonium, and nitrite. The extended model simulates heterotrophic denitrification, DNRN, DNRA, anammox, and nitrification of ammonium and nitrite and thus allows for a detailed representation of a step-wise reduction of fixed nitrogen in hypoxic zones and oxidation of reduced N-species in oxic waters. The updated biogeochemical model is included in the new global ICOsahedral Non-hydrostatic Ocean model ICON-O developed at the Max Planck Institute for Meteorology. ICON-O features a flexible, triangular grid created by recursively subdividing the original 20 triangles of the icosahedron resulting, in our configuration, in an average resolution of 40 km and 235,403 triangles. We describe the tuning and spin-up of a pre-industrial control simulation and compare model results with global and local estimates to quantify the N cycle (e.g., rates of primary production, N2 fixation, nitrification, DNRN, DNRA, anammox). We further report results from a historical transient simulation focusing on N dynamics within the oxygen minimum zone of the Eastern Tropical South Pacific.
Optimal stomatal control in the presence of leaf-atmosphere coupling
Authors: Schymanski Stan , Milenovic Milan , Thakur Gitanjali
Published: February 2023

Plant leaves absorb solar radiation and carbon dioxide (CO2) from the atmosphere while releasing water vapour, oxygen and heat to the atmosphere. The leaf-atmosphere interface is hence the primary determinant of water-carbon interactions, where stomata control transpiration according to soil water availability, but at the cost of reducing carbon uptake by photosynthesis. It has been proposed that stomata not only respond to water stress, but function in a way to maximise a plant's long-term carbon gain by dynamically economising plant available water according to varying environmental conditions (Cowan and Farquhar, 1977). While the search for the relevant costs of stomatal opening focuses more and more on the costs of the infrastructure needed to supply water to the leaves, the consequences of opening stomata in the presence of leaf-atmosphere feedbacks, potentially resulting in a cooling and humidification of the air at the diurnal scale, hence reducing evaporative demand (Cowan, 1978), and/or depletion of atmospheric CO2, hence reducing CO2 uptake, have so far not been considered in stomatal optimality modelling. It has been shown that optimal response of vegetation to even small long-term variations in atmospheric CO2 can lead to substantial changes in land-atmosphere exchange (Schymanski et al., 2015), while the effect of trends in atmospheric vapour pressure concentration and temperature has also been documented widely. However, little research has been conducted on the optimal behaviour of plants in the presence of land-atmosphere feedbacks.Here we present a theoretical analysis and preliminary experimental results of (optimal) stomatal control in the presence of leaf-atmosphere coupling. The coupling strength is represented theoretically by adding an additional control volume representing the leaf boundary layer or canopy air space, and experimentally by varying the flow rate of dry and CO2-rich air into a leaf cuvette. We discuss the positive and negative effects of a de-coupled canopy air space for leaf gas and energy exchange, and present experimental and mathematical methods to put them into relation to each other.Literature:Cowan, I. R.: Water use in higher plants, in: Water: planets, plants and people, edited by: McIntyre, A. K., Australian Academy of Science, Canberra, 71–107, 1978.Cowan, I. R. and Farquhar, G. D.: Stomatal Function in Relation to Leaf Metabolism and Environment, in: Integration of activity in the higher plant, edited by: Jennings, D. H., Cambridge University Press, Cambridge, 471–505, 1977.Schymanski, S. J., Roderick, M. L., and Sivapalan, M.: Using an optimality model to understand medium and long-term responses of vegetation water use to elevated atmospheric CO2 concentrations, AoB Plants, 7, plv060, https://doi.org/10.1093/aobpla/plv060, 2015.
Preprocessing intense precipitation forecasts to improve flood predictability for small and quick responding catchments
Authors: Hegdahl Trine Jahr , Thorarinsdottir Thordis , Engeland Kolbjørn
Published: February 2023

Small catchments have a quick flood response subject to intense precipitation. Previous studies show a lack of predictability for rain induced floods in these catchments. The aims of this study are to (i) apply processing techniques that focus on improving high to extreme precipitation forecasts, and (ii) evaluate how and if the spatial distribution of precipitation within a catchment affects the flood forecast, and the ultimate effect on flood predictability. Even though preprocessing precipitation has shown to improve flood prognosis, high (intense) precipitation values are still difficult to forecast correctly. In this study, we use precipitation forecasts from the regional weather forecasting model AROME-MetCoOp (MEPS, a 30-member lagged ensemble with a grid resolution of 2.5 km) and the global European Center of Medium-Range Weather Forecasts Integrated Forecasting System (ECMWF HRes and ENS, grid resolution of ~8km and for the ensemble ~16 km). MEPS serves as the reference forecast and is used in the operational flood forecasting system in Norway. For the ECMWF HRes and ENS we will apply techniques focusing on the high precipitation values. We will use Bayesian Model Averaging and apply a sampling approach that ensures that the tail of the posterior distribution is represented. We will also use a quantile regression method that employs an extreme value distribution in the tail. To assess the streamflow forecasts from all ensemble forecasts, a gridded HBV model run at a 3 hourly temporal resolution is used. The performance of flood forecasts for the different preprocessing approaches for the precipitation ensemble forecasts will be evaluated. For intense precipitation events the spatial distribution of precipitation within a catchment will be evaluated with an emphasis on the ultimate effect on estimating flood peaks for small and quick responding catchments. 
Towards a 3D crustal geomodel of the Western Alps in the French Geological Reference Platform (RGF)
Authors: Bader Anne Gaelle , Calcagno Philippe , Bellahsen Nicolas , Paul Anne
Published: February 2023

The French Geological Reference Platform (RGF) is a national programme for acquisition and management of geological data launched in the early 2010’s and coordinated by BRGM (https://rgf.brgm.fr). It involves the geosciences community to develop a new 3D knowledge of the underground to support innovative responses to a wide range of scientific first order questions as well as issues our society is facing. The RGF’s Alps and surrounding basins (Abp) worksite aims at a better understanding of the 3D structure of an emblematic mountain range and at addressing the impact of climate change and geological risk.Within the RGF’s Abp, we proposed to build a 3D reference geomodel covering the area of the whole worksite ([41.5°N-48°N; 4°E-10°E]; ~350 000 km²) investigating the subsurface down to the Moho. This geomodel aims at federating the geoscientific community and intends to integrate existing data and information, e.g. geology, geophysics, relevant at that scale. It will be updated using the data acquired during the Abp worksite and serve to set up boundary information for local studies.The geomodel is constructed in a collaborative approach where contributors discuss their data and knowledge and converge to a common interpretation of the investigated major geological boundaries that are the Moho (European lithosphere, Adriatic lithosphere, Ligurian backarc basin) and the boundaries of the subduction wedge.We present here the state of progress of the geomodel based on the geological interpretive sections established at lithospheric scale by the RGF community (see Bellahsen at al., this session) and the integration of the available geophysical data and models (velocity models Vp and Vs, seismic reflection and refraction, gravimetry, etc.).This work benefits from the French Geological Reference Platform - Alps and surrounding basins programme funding.
The Baltic Sea modelling using coupled ROMS and CICE models.
Authors: Muzyka Maciej , Jakacki Jaromir
Published: February 2023

The coupled ice-ocean model of the Baltic Sea has been prepared to simulate the basic physical parameters. The system is based on sigma-coordinates the Regional Ocean Modelling System (ROMS) and the Los Alamos Sea Ice Model (CICE) and such coupled system was never adapted for Baltic Sea region. It is configured for two horizontal resolutions (1.25 NM and 0.5 NM) that are currently in use with 30 and 26 vertical layers respectively. Both models are forced by two atmospheric data sets: ERA5 and UERRA. Lateral boundary conditions are implemented in Kattegat region as an assimilated sea level, temperature and salinity. Also run off from the catchment model (Balt-HYPE) that covers whole Baltic Sea region have been applied.Preliminary results from the first few years of the simulation are very promising. The introduced boundary conditions are stable, and the simulation seems to work correctly.The first comparisons with the Parallel Ocean Program (POP) model, previously used with the same horizontal resolution suggest the model meets the expectations related to the correct work of the Danish Straits, the transport of water masses in the bottom layers and have better dynamics and correctly simulates the free surface. The simulations have been performed since 1992. ROMS model results will be presented in comparison with other data delivered by: in-situ measurements during research cruises (point and cross-sections), satellite imaging, modelling. If it will be possible, comparisons with data based on gliders measurements from The Voice of the Ocean are going to be shown.This study was funded by the NCN “Turbulent Mixing in the Slupsk Furrow” grant number 2019/B/ST10/02189Calculations were performed using computers of the Academic Computer Centre in Gdańsk.
Prospects for in-situ Rb-Sr mica geochronology in metamorphic petrology
Authors: Zack Thomas
Published: February 2023

The emerging field of “in-situ beta decay dating” has enormous potential for Earth Sciences. Here, the Rb-Sr system is the most advanced, although other systems (e.g., K-Ca, Lu-Hf, Re-Os) promise exciting opportunities as well. In this contribution, I want to first highlight several analytical and conceptual advances made with regard to in-situ Rb-Sr geochronology, and in particular utilizing the mica group (mostly biotite, muscovite and glauconite): (1) the community (e.g., Redaa et al, 2022) has made important progress characterizing the reference material Mica-Mg (from CRPG) for Rb-Sr ratios and Sr isotope composition, used as a nanopowder pellet, it currently serves in most laboratories as a primary reference material; (2) several new natural mica samples have been distributed to several laboratories to serve as secondary reference materials (Rösel & Zack, 2022). Both these activities serve not only to improve precision and accuracy of this technique, but in general allows better comparison of results of different studies. Furthermore, (3) many micas are almost devoid of Sr when forming, which allows treating them similar to zircon in the U-Pb system, meaning that the common Sr can simply be estimated, making the isochron approach obsolete (Rösel & Zack, 2022). This has important practical implication; so-called single spot ages can be utilized to map out age distribution within single crystals, target crystals of different textural context or even used in provenance studies of detrital mica (Rösel et al., this conference). Finally, (4) as most analytical facilities where in-situ beta decay dating is possible employ a quadrupole ICP-MS, selecting isotopes for spot analysis are not limited to Rb and Sr isotopes, but can set to cover all elements of interest from Li to U. With sufficient care in the choice of calibration material, it is possible to not only couple age information with trace element signatures, but even calculate mica mineral formula with surprising accuracy. In my presentation I want to illustrate how in-situ Rb-Sr mica geochronology can be utilized in the field of metamorphic petrology. For further applications in metamorphic settings, please also see Barnes et al. (this session).
Flood impacts beyond the direct and physical ones: the case of the Po catchment in Italy
Authors: Martina Mario Lloyd Virgilio , Arosio Marcello , Arrighi Chiara , Domeneghetti Alessio , Farina Gabriele , Giusti Riccardo , Molinari Daniela , Pilotti Marco , Scorzini Annarita
Published: February 2023

Flooding is among the leading climatic threats to people’s livelihoods, affecting development prospects worldwide. While the danger is already substantial, climate change and rapid urbanization in flood zones will likely further drive-up flood risks.  The support from flood risk assessment studies, which quantify the impacts of hazardous events on the built environment, economy and society, is fundamental for defining and implementing strategies to manage and reduce flood risk effectively. However, according to the typology of considered assets, there are different methodologies for flood risk assessment. While for direct physical and monetary dimensions, the scientific community offers a variety of widely used models, the application of models beyond these dimensions is much less frequent, and the selection and implementation of a model for estimating indirect losses or impacts for a given application case are not straightforward.This work presents the lesson learnt from the recent updating process of the Flood Risk Management Plan of Po River District Authority carried out in the context of the MOVIDA project ((https://sites.google.com/view/movida-project, 2022), in compliance with the European Floods Directive (2007/60/EC). The analysis spread across the following assets: residential buildings, crops, dairy farms, commercial and industrial sectors, strategic facilities, roads and railways, cultural heritage, environment and population. In particular, this study critically examines and discusses the needs and challenges faced by the research consortium to implement a comprehensive impact. Furthermore, the major bottlenecks for the different assets are explored across the standard dimensions: state of art, data availability and openness, spatial/temporal resolution and scale, methodology framework and implementation.
The influence of lithology on the Magnitude–Frequency-Distribution of earthquakes
Authors: Collettini Cristiano , Tinti Elisa
Published: February 2023

The earthquake Magnitude-Frequency-Distribution, FMD, is usually modelled with the Gutenberg-Richter relation law, where the b-value controls the relative rate of small and large earthquakes. b-value has been documented to show an inverse dependence on differential stress, it increases with the fault roughness or during fluid-induced earthquakes. For some seismic sequences a near real-time characterization of the b-value has been used to discriminate between foreshocks and aftershocks. Here we examine the influence on b-values of different lithologies hosting earthquakes.In general, seismicity not only localizes along the major structures where mainshocks nucleate, but it can be also distributed within volumes of the seismogenic layer characterized by different lithologies. For the Mw 6.5 2016–2017 Central Italy seismic sequence, the lithology can be properly defined by seismic reflection profiles. Here the fractured carbonate of the Apennines, located at almost 1-2 km and 4-6 km of depth, are characterized by b-values ranging between 1.3 and 1.4 that can be diagnostic of brittle dominated deformation. At 2-4 km and 6-10 km of depth, the Triassic Evaporites showing a bimodal brittle-ductile deformation and compartmentalized fluid overpressure (documented in deep boreholes) are linked to high b-values, in the range of 1.5-1.65 reaching 1.80 for clustered swarms. Between 10-12 km of depth the phyllosilicate rich basement, with its predominant velocity strengthening behaviour, is hosting small magnitude earthquakes with b-values around 1.4. Our results indicate that away from the large earthquake faults, characterized by a stress dependent elasto-frictional rheology, FMD are strongly controlled by rock lithology and style of deformation.
Preliminary study about soil compaction and awareness in grasslands in Carinthia (south Austria)
Authors: Garcia Santos Glenda , Puff Marianna , Orel Martin , Bohner Andreas
Published: February 2023

The study of the causes and possible remediation strategies at regional level complies with the current European Green deal to monitor soil compaction. We have investigated the influence of different management strategies (use of cattle and machinery) on the storage density and the penetration resistance of permanent grasslands in the south of Austria (Carinthia) based on the recent evidences of soil compaction in two grasslands as studied by Klinger et al. in (2019). Based on this, we have extended the study by selecting more than ten grasslands within two catchments with different management strategies.The studied indicators were bulk density, soil texture, plant indicators, infiltration capacity, water repellence, water content and electric conductivity at the surface level. Soil profiles of approximately 30 cm were also studied to detect the possible compaction layer and vertical bulk density variations. First results may explain spatial topographical differences i.e. slope and hydrological soil properties and interestingly in some cases, possible correlation between the use of cattle and number of entries in the field and compaction level. We checked if these results contributed or matched farmers awareness.
Long-term effect of a basal magma ocean on Martian mantle convection
Authors: Cheng Kar Wai , Ballmer Maxim , Tackley Paul
Published: February 2023

It has been proposed that a basal magma ocean (BMO) may have existed, or even still exists, at the base of the Martian mantle [1]. One formation scenario for such a BMO involves a mantle-scale overturn just after the crystallization of the main magma ocean. In this case, the BMO would be enriched in iron and heat-producing elements (HPE), and hence gravitationally stable at the base of the mantle, with potential effects on the efficiency of mantle convection. The Insight mission has allowed geophysical investigation of the Martian interior and has indeed provided seismic evidence of a basal liquid silicate layer just above the core-mantle boundary. It is thus crucial to understand the effect of such a layer on the long-term evolution of the interior of Mars.Here, we model thermochemical mantle convection and crust production for a Mars-sized planet in a 2D spherical annulus geometry using code StagYY.  Assuming that the top of the BMO is at ~1800 km radius, we parameterize the basal magma ocean as a ‘primordial layer’ with a low viscosity and a high effective thermal conductivity to account for the enhanced effective heat flux in a liquid layer due to turbulent flow. HPE are preferentially partitioned into the silicate liquid layer following a mass balance equation assuming an interstitial porosity.  We systematically vary BMO thickness and interstitial porosity in order to study the outcome of the different HPE distributions.  The liquid density, which is attributed by the different degrees of iron enrichment, is also examined to explore the mechanical stability and entrainment of the BMO.We present results of our models, comparing our present-day temperature profiles with areotherms deduced from seismic observation [2,3].  We find that the interstitial porosity is an important factor that determines the thermal structure of the mantle throughout Martian evolution. A value of ~50% provides the best fit with crustal production history, crustal thickness, HPE enrichment in the crust, as well as the seismically-constrained present-day areotherm. This result suggests that the initial HPE partitioning has not been controlled by end-member fractional crystallization of the main magma ocean (for which interstitial porosity would be close to 0%), and/or that some re-equilibration occurred during subsequent overturn. Meanwhile, the BMO thickness, within the uncertainties from seismic inversion, does not strongly influence Mars thermal evolution. [1] Samuel et al. (2021) doi:10.1029/2020JE006613[2] Khan et al. (2021) doi: 10.1126/science.abf2966[3] Duran et al. (2022) doi: 10.1016/j.pepi.2022.10685
The role of soil methanotrophy in offsetting methane emissions at farm level – the potential contribution of silvopastoral systems and biochar additions
Authors: Walkiewicz Anna , Rafalska Adrianna , Kubaczyński Adam , Rolo Victor , Vivas Maria , Moreno Gerardo , Osborne Bruce
Published: February 2023

Soils may act as a biological sink for methane (CH4) through methanotrophic activity. This process is particularly important in the farming sector, as CH4 emissions from livestock and manure storage often dominate the greenhouse gas (GHG) budget. This places a particular emphasis on the identification of management practices that may increase the capacity of soils to absorb CH4. In this study we examined  practices with the potential to improve the CH4 balance at farm level, including the effect of biochar as a soil additive, and the potential of silvopasture systems. Experiments conducted under controlled laboratory conditions revealed that the addition of biochar increased the rate of CH4 oxidation in the mineral and manure-fertilized silty soil, although such effect has not been confirmed in all soil types. Using biochar produced from crop by products  may also provide a way of managing agricultural wastes with concomitant practical benefits. Silvopastoral systems can also alter the CH4 balance of farms because of the effect of the presence of trees on microclimate and soil conditions. However, relatively few studies have assessed the potential of trees to improve CH4 budgets at the farm level in Mediterranean silvopastoral systems. In-situ measurements of soil-atmosphere CH4 fluxes were undertaken to evaluate the CH4 uptake potential of pastures below and beyond tree canopies. Preliminary results showed CH4 emissions in open tree-less pastures, but not under trees, which showed mainly CH4 uptake. This result highlights the potential of silvopastoral systems to improve the CH4 balance at farm level perhaps in combination with biochar additions. Nevertheless, the mitigation potential of different soil additives and silvopastoral  practices at farm level are still a subject of research in need of further studies.This work was funded by the National Centre for Research and Development within GHG Manage (ERA-GAS/I/GHG-MANAGE/01/2018) and ReLive (CIRCULARITY/61/ReLive/2022); Joint Call of the Co-fund ERA-Nets Programme, SusCrop (Grant N° 771134), FACCE ERA-GAS (Grant N° 696356), ICT-AGRI-FOOD (Grant N° 862665) and SusAn (Grant N° 696231), Spanish Ministry of Science and Education (PCI2021-122100-2A).
Unsupervised statistical classification of the Antarctic marginal ice zone.
Authors: Day Noah , Bennetts Luke , O'Farrell Siobhan
Published: February 2023

This work presents a new method for quantifying the Antarctic marginal ice zone (MIZ). The MIZ acts as an interface between the open Southern Ocean and the consolidated inner pack, and is generally described as area of sea ice affected by ocean surface waves. We use standalone CICE6, which includes a floe size distribution with atmospheric, oceanic and wave forcing, to simulate the evolution of Antarctic sea ice from 2010 – 2020. CICE output variables were categorised as static (sea ice concentration, age, thickness, etc.), thermodynamic, and dynamic. Unsupervised statistical methods were used to classify distinct sea ice regions and then to identify the dominant processes which contribute to the spatial and temporal variance of Antarctic sea ice cover. The unsupervised sea ice classification agrees with recent MIZ extent estimations using altimetry observations of wave attenuation. The addition of floe size information enhanced our MIZ classification to include high concentration pancake fields (which are promoted by waves). These results support the inclusion of floe size within sea ice modelling, and the importance of multi-variate approaches to describe sea ice.
Traveling for academic research : patterns, determinants and mitigation options
Authors: Aumont Olivier , Ben Ari Tamara , Mariette Jérôme , Jeanneau Laurent , Spiga Aymeric , Lefort Gaelle , Roche Philippe-e , Santerne Alexandre , Estevez-Torres André
Published: February 2023

In the midst of climate change, academic travels - one salient aspect of the carbon footprint of research activities - are at the center of a growing concern. Mitigation options often focus on two dimensions : (i) decreasing the frequency of attendance to conferences and (ii) modal shift in transport. Here, we analyze professional travel in academia from a unique database compiling about 100 000 travels from about 150 research labs across a large array of disciplines and localities in France to detail the structure, patterns and heterogeneity of national and international research travels for research purposes. We estimate the mitigation potential of a series of options encompassing but not limited to institutional options. We show that, if short distance traveling (typically below 1000 km) are largely dominant in number, their relative mitigation potential via modal shift is small (i.e., below 15%). On the other hand, long distance traveling, which is often associated with international collaborations or field work hold a much larger mitigation potential but question the very nature of research activities. We propose ambitious sobriety options to robustly decrease travel-induced GHG emissions in academia and discuss their acceptability in the context of the French public research system.
Changes in suspended sediment concentration in the coastal waters of the Western Pacific from 1984 to 2022
Authors: Zhou Tao , Cao Bowen , Yang Xiankun
Published: February 2023

Asian rivers are significant contributors to the world’s coastal sediment flux and the Western Pacific Coast (WPC) receives most of them. In recent years, Natural changes and human activities constantly change the suspended sediment concentration (SSC) in waters of the WPC; resulting in significant changes in coastal and marine systems, consequently altering the global biogeochemical cycle. However, monitoring these changes is difficult, confounded by the lack of observational data and unavailability of globally SSC algorithms. Here, based on the platform of Google Earth Engine, we retrieved the SSC in the waters where stretching 10 nautical miles from the WPC using multi-source imagery from Landsat-TM/ETM+/OLI sensors (from 1984-2022) to obtain its long-term dynamics using 3 different SSC algorithms. The results indicate that the 3 retrieve algorithms obtained satisfactory results in temporal-spatial variation trend of SSC. We discovered that some estuaries in the WPC show significant decreasing changes. For example, the spatial distribution of SSC in the Pearl River Estuary (PRE) represented a trend of high along the west coast and low along the east coast. Over the past 39 years, the SSC showed a relatively evident decreasing trend in most PRE regions; In the Yangtze Estuary (YRE), the SSC in the outer estuaries was generally significantly higher than that in the inner and SSC demonstrated an overall declining pattern in time; For the Yellow River Estuary, the highest of SSC is located a peripheral zone in front of the estuary, and also showed an overall decreasing trend in time.