bluuebunny/crossref_metadata_2025 huggingface dataset:
Learning from Failure? Carbonate U-Pb and Quartz Fluid Inclusion 40Ar/39Ar Geochronology 
Authors: Rutte Daniel , Tomaschek Frank , Kuiper Klaudia , Wijbrans Jan , Froitzheim Nikolaus
Published: February 2023

We attempted to determine the timing of deformation along a structurally and petrologically diverse set of brittle-ductile shear zones and faults along the Austroalpine-Pennine boundary in the Central Alps using U-Pb and 40Ar/39Ar geochronology. Among the structures studied are the Turba mylonite shear zone, Gürgaletsch shear zone, Martegnas shear zone, Engadine line, Muretto fault, Septimer fault, Silvretta basal contact and - as an outlier of the main focus of the study - the Glarus thrust.

We sampled carbonate and quartz mineralizations with clear temporal relation to the larger scale structures, i.e., pre-, syn- or post-tectonic. These were pristine or recrystallized veins, slicken fibers, recrystallized clasts, and mylonitic layers. To determine crystallization or recrystallization ages we analyzed U-Pb isotopic compositions of carbonate mineralizations using LA-ICP-MS analysis and Argon isotopic compositions of fluid inclusions in quartz mineralizations using the step-wise crushing technique.

Both methods resulted in complex datasets for all samples, which so far do not allow for a clear age interpretation. Carbonate U-Pb samples either had too low U-contents or too high common Pb and - partly as a result of the other two characteristics - too little radiogenic ingrowth to calculate intercept ages. Step-wise crushing of quartz separates yielded complex Ar release spectra with large amounts of excess-Ar and variable but mostly low 39ArK contents considered both in absolute and relative values.

In an attempt to aid more success in future application of the two techniques we present our methods, results and discuss our observations.
Is your ensemble of CMIP6 models consistent with IPCC AR6?
Authors: Humphrey Vincent , Merrifield Anna , Knutti Reto
Published: February 2023

The Intergovernmental Panel on Climate Change (IPCC) assesses the sensitivity of the climate system to increases in greenhouse gas concentrations using multiple lines of evidence, covering paleoclimate data, historical observations, and numerical Earth system model (ESM) simulations. Within IPCC’s latest Assessment Report (AR6), there is, for the first time, a non-negligible difference between the most likely rate of warming estimated in the report and the average warming rate simulated by the ESMs that participated in the Coupled Model Intercomparison Project (CMIP6). This discrepancy occurs because a large number of CMIP6 models have projected future warming rates that are higher than previously reported but quite unlikely according to historical observations. The consequence is that using a random selection of CMIP6 simulations is likely to overestimate historical and future warming (compared to what is assessed in the IPCC report), potentially leading to avoidable inconsistencies when compared to observations or greater projected changes compared to what could be inferred from CMIP5.As this constitutes a wide-spread obstacle and limitation to using CMIP6 simulations ‘out of the box’, we propose here a simple model weighting method with the objective to address this problem. Our approach can be used to 1) evaluate the extent to which any given set of CMIP6 simulations is consistent with IPCC-assessed warming rates and 2) calculate the appropriate model weights so that potential inconsistencies are reduced as much as possible. The calculation of the weights is solely based on the user’s selection of a CMIP6 subset and does not require any data manipulation. The weights can then be easily implemented in existing analyses to calculate weighted (i.e. instead of just arithmetic) multi-model means, weighted quantiles, etc. We demonstrate the interest and flexibility of the method with some examples, including global to regional assessments of historical and projected changes in temperature and precipitation. We illustrate the extent to which applying model weights can reconcile otherwise divergent scientific results and provide assessments that are more robust across CMIP generations.
Multi-Satellite Whistler Wave Observations at the Earth’s Bow Shock
Authors: Kuzichev Ilya , Vasko Ivan
Published: February 2023

Whistler waves play important role in electron dynamics in space plasmas. They are capable of accelerating and scattering electrons, shaping the electron velocity distribution function of the solar wind electrons and providing a mechanism to fill the inaccessible phase space regions for electron heating at the interplanetary shocks and the Earth’s bow shock. In the pristine solar wind and near the shocks, whistler waves are generated by a variety of different instabilities, including whistler heat flux and anisotropy instabilities and beam instability.

Numerical simulations demonstrate that wave properties strongly affect how whistler waves interact with particles. Even for quasi-parallel waves, direction of propagation with respect to the heat flux might crucially change the effect of the waves on the electron distribution. Hence, it is important to know wave properties, including the direction of propagations, which can be inferred either from multi-spacecraft observation or from the electric field measurements (in addition to magnetic field data) aboard one satellite. But, unfortunately, electric field data is often less reliable than the magnetic field measurements, as electric field is calculated using the potential difference across antenna. The effective length of the antenna usually depends on wave frequency, and this frequency response factor can have large uncertainties.

In this report, we present multi-satellite analysis of the whistler waves observed at the Earth’s bow shock by MMS satellites. We implemented the phase shift analysis technique to calculate wave parameters, such as wave vector and phase velocity, and compared the results with the whistler dispersion equation. These parameters allow calculating the electric fields from Maxwell’s equations. We compared theoretical electric fields with the observed ones and estimated the antenna effective length in the frequency range around 100 Hz.

This work is supported by the NASA HGI grant 80NSSC21K0581.
Forecasting soil moisture on a spatial and temporal scale using machine learning algorithms
Authors: Chrysanthopoulos Efthymios , Pouliaris Christos , Tsirogiannis Ioannis , Kallioras Andreas
Published: February 2023

While the observations from earth-observing satellites and in-situ weather meteorological and monitoring stations continue to expand, researchers are to deal with an abundance of data and, consequently, with a long modeling procedure. Machine learning algorithms, as universal nonlinear function approximation tools, are effective in analyzing and modeling spatio-temporal environmental data, more efficiently, either in time or in terms of the availability of various variables, than physically-based models.Soil moisture is an essential climatic parameter, especially for understanding and forecasting variations in surface temperature, precipitation, drought, flood, and the effects of climate change. As a parameter with high spatial and temporal variability, it is a strong necessity for predictive models that embed spatially irregular measurements, which stand for spatially distributed weather meteorological and monitoring stations. To date, most approaches, that have been documented in the literature, model environmental data only at the discrete locations of the monitoring stations.This research aims to employ a recently proposed methodology, for spatio-temporal prediction of environmental data (Amato et al., 2020), and to propose a new methodology for spatio-temporal prediction of soil moisture in lowland areas, making use of the basic hydrologic premise that precipitation and temperature strongly hinge on topography. The features of the machine learning models used to predict soil moisture within the research area are the meteorological parameters of several agro-meteorological weather stations that have been installed at the site.The study area is the plain of Arta, located in the Epirus region (NW Greece), and includes the lower part of the watersheds of rivers Aracthos and Louros. The final receptor for upstream surface water and groundwater is a sensitive and complex system of wetlands, the marine ecosystem of Amvrakikos. The research area is receiving a lot of attention because of its agricultural characteristics and water infrastructures (extensive irrigation and drainage network, pumping stations, and hydroelectric dam).Acknowledgments: This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call SUPPORT OF REGIONAL EXCELLENCE (project code MIS: 5047059).Amato, F., Guignard, F., Robert, S., & Kanevski, M. (2020). A novel framework for spatio temporal prediction of environmental data using deep learning. Scientific Reports, 10(1), Article 1. https://doi.org/10.1038/s41598-020-79148-7 
North Atlantic hurricane activity in a warmer climate: implications for property catastrophe reinsurance
Authors: Comola Francesco , Dawson Siti , Stahel Michael , Paul Hilary , Märtl Bernhard , Koller Pascal
Published: February 2023

North Atlantic hurricanes are one of the weather-related perils that most severely impact insured properties along the US East Coast, and thus represent a key exposure for most reinsurance and insurance-linked security (ILS) portfolios. The hurricane models traditionally used to quantify re/insurance risk account for the effect of fundamental climate circulation features, such as the El Niño Southern Oscillation (ENSO) and the Atlantic Multidecadal Oscillation (AMO). However, the longer-term impact of global warming on hurricane-exposed reinsurance portfolios is still largely unknown. Here, we leverage recent scientific insights and historical records to explore the potential link between global warming and hurricane insured losses. Historical records suggest that the annual frequency of North Atlantic hurricanes does have a material impact on industry losses (rank correlation coefficient ~0.4). However, both models and historical trends seem to indicate no change, or even a slight decrease, in North Atlantic hurricane frequencies in a warmer climate. We also find that a potential increase in the proportion of hurricanes that reach major intensities, expected to be of the order of 10-20% according to the 2021 IPCC report, might lead to a 5-10% increase in industry losses. A similar increase in industry losses might also result from the higher hurricane precipitation rates, which are projected to increase by 11- 28% according to the 2021 IPCC report.  This suggests that the impact of global warming on hurricane insured losses may be significant, albeit not as critical as other fundamental loss drivers, such as urban development, demographic growth, as well as economic and social inflation.
Performance assessment of the DSSAT-CERES-Wheat model under different irrigation strategies in the semi-arid region of Marrakesh
Authors: Ech-chatir Lahoucine , Er-Raki Salah , Meddich Abdelilah , Rodriguez Julio Cesar , Khabba Said
Published: February 2023

Water scarcity is a major problem in the arid and semi-arid areas of Morocco, where irrigation is essential for agriculture. Crop growth models can enhance water use efficiency, thus providing an economic benefit while reducing pressure on water resources. In this study, we evaluated the modeling performance of the DSSAT-CERES-Wheat model in estimating Evapotranspiration (ETa), Total soil water (TSW), Grain yield, Tops weight and phenological stages of winter wheat in the semi-arid region of Tensift Al Haouz, Marrakech. The simulation was performed at a daily time step during two successive growing seasons 2002/2003 and 2003/2004. The model calibration was done firstly on two fields and ETa, TSW phenological stages, and productive variables were calibrated after the comparison of the simulated and observed data. Afterward, the validation was performed on four fields during the two growing seasons. The results showed that the model simulates reasonably good Grain yield, Tops weight and phenological stages. Moreover, The average values of  RMSE  between observed and measured ETa, TSW, Grain yield and Tops weight were respectively, 0.70mm/day, 25mm, 0.6 t/ha and 2 t/ha for the validation fields. Statistical parameters like R2, d, and NRMSE were additionally used and showed that the model simulates acceptably the above-mentioned parameters. Furthermore, The Penman-Monteith FAO56 and Priestley and Taylor Evapotranspiration simulation methods were compared, the average values of d  and R2 were respectively 0.85, 0.70 for the Penman-Monteith method, and 0.80, 0.65 for the Priestley and Taylor method. Thus, the DSSAT model can be considered a useful tool for monitoring the management of wheat in arid and semi-arid regions.Keywords: DSSAT, wheat, irrigation, water scarcity, crop model
Test of gravitational redshift by combining tri-frequency links between spacecraft and ground station
Authors: Shen Ziyu , Shen Wen-Bin , Zhang Tengxu , He Lin , Zhang Pengfei
Published: February 2023

We propose an approach for testing the gravitational redshift based on frequency signals transmitted between a spacecraft and a ground station. The main idea is to integrate one uplink signal from the ground to the spacecraft and two downlink signals from the spacecraft to the ground. Based on the integration and specific correction models, the gravitational shift of the signals between the spacecraft and the ground station can be detected at a high precision level. The gravitational redshift effect can be tested at about E-6 to E-8 levels in different cases for less than one month if the stability of onboard the atomic clock reaches E-17/day. Compared to the scheme of the Gravity Probe-A (GP-A) experiment conducted in 1976, in the new approach, any onboard signal transponder is not required, and the frequency values of the three links can be relatively arbitrary. Since the hardware requirement is decreased, any spacecraft can be a candidate for gravitational redshift experiment if it can emit two different frequency signals and receive a frequency signal from the ground. This study is supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 42030105, 41721003, 41631072, 41874023, 41804012), Space Station Project (2020)228, and Natural Science Foundation of Hubei Province (Grant No. 2019CFB611).
Coastal ecosystems’ health assessment in Kenya: Use of anthropogenic nutrients and phytoplankton diversity metrics
Authors: Oduor Nancy Awuor , Nils Moosdorf
Published: February 2023

Coastal habitats offer a wide range of services that support human welfare and vital ecosystem functions utilized by various marine biodiversity during their life cycle. However, these habitats are becoming more vulnerable to anthropogenic nutrient pollution due to the growing human population and intense socio-economic activities in coastal areas. This study identified, mapped, and conducted a comprehensive ecological quality assessment in sea turtle foraging sites using physicochemical indices and phytoplankton assemblages between September 2021 and July 2022.The study established a total of 154 turtle foraging sites spread over 264 km of the Kenyan coast with 70% of the sites located in marine unprotected areas. The benthic composition sites frequented by turtles were dominated by seagrass and corals while seaweeds dominated areas where turtles are no longer sighted. The study established an average concentration of dissolved inorganic nutrients - NOX (Nitrate + Nitrite), ammonium (NH4-N), phosphate, and silica of 9.98. 12.77, 0.67, and 6.40 µmol/L, respectively. The sites were well-oxygenated. The study also revealed the presence of 154 phytoplankton species belonging to 119 taxa with the species composition dominated by diatoms (59 %,), dinoflagellates (23%), and cyanobacteria (9%), respectively. The total relative abundance was dominated by three non-harmful diatom species and eight harmful species including six diatoms one dinoflagellate and one cyanobacterium. About half of the sites were in a ‘Moderate’ ecological state, estuarine and creeks were ‘Poor’ and ‘Bad’ while nearshore and oceanic environments were ‘Good’ based on both nutrients and phytoplankton (Chl a). Most ‘Poor’ and ‘Bad’ conditions occurred during the rainy season. The region provides important fisheries and tourism and foraging grounds to five of the seven endangered sea turtles species. These findings will help to conserve the remaining sea turtle population, and livelihoods of coastal communities and justify effective management of land-based activities to minimize eutrophication.
Selection of relevant black crusts samples as ancient air pollution archives
Authors: Ropiquet Mathilde , Verney-Carron Aurélie , Chabas Anne
Published: February 2023

Since the Industrial revolution and due to increasing anthropogenic emissions, the composition of the atmosphere has been modified, leading to climate change and pollution. The impacts of pollution were depicted through paintings and writing from the beginning of the 19th century, but pollution measurements are relatively recent. In order to obtain ancient air pollution data, proxies in urban area need to be found.Black crusts formed on limestone and marble monuments in urban area seem to be a good candidate as local proxy. Mainly composed of gypsum (CaSO4.2H2O), they are a chemical alteration pattern resulting from the reaction of the dissolution of the calcite (CaCO3) of the stone and of sulfation by sulphur dioxide (SO2) from the atmosphere. Particulate matter accumulates in the newly formed gypsum layer in sheltered area from the rain, thus giving the black crust a passive sampler potential.To use black crusts as past air pollution archives, samples were collected at Père Lachaise cemetery (Paris) on ancient, dated (1820-1887) and unrestored limestone or marble tombs. Different types of analyses were performed to study sample morphology (by Optical Microscope), particulate matter (by Scanning Electron Microscopy) and chemical composition (especially major elements and trace metals by ICP-AES, LA-ICP-MS). Results underline two important features to use black crusts as past air pollution archives. First, the low variability of chemical composition of black crusts from Père Lachaise cemetery highlights that the black crusts are representative of the site and register the background pollution. Then, the morphology (laminar vs. dendritic) of black crusts is a key parameter to sample black crusts as the stratigraphy is much better preserved in laminar black crusts.
Cover crop C inputs; Multiple aerial and isotope insights from a long-term field trial.
Authors: Hood-Nowotny Rebecca , Fernández-Balado Celia , Schott Katharina , Wawra Anna , Konzett Matthias , Heiling Maria , Dercon Gerd
Published: February 2023

Use of cover crops, mulches and other soil management practices have been widely promoted within the EU, as measures to draw down carbon dioxide and increase soil organic carbon in the fight against climate change. These approaches are being investigated in a number of programs and projects EU-wide, for example the EJP-SOIL program.We used a long-term fully replicated maize based field trial with different crop and soil management practices, namely residue incorporation and/or inclusion of a cover crop, to explore carbon sequestration potential. We used natural abundance stable isotope approaches to follow the fate and residence time of mulched residues and to determine the most stable organic matter pools in these systems. We measured isotope signatures in particulate organic matter (POM), mineral associated organic matter (MOAM), stable aggregate bound organic matter (IA-POM) and soil microbial biomass (Mi-BIO) to characterize the impact of the soil fraction, on the fate and stability of the carbon pool and to test a number of emerging paradigms in soil science. We hypothesized that the residence time of the POM fraction and MOAM fractions would be lower under higher nitrogen inputs and that it would be possibly to detect these shifts using a stable isotope approach. Moreover, we used handheld and unmanned aerial vehicle UAV-captured multispectral data to investigate impacts of management on a plot scale.Preliminary results show that even at low mulch rates (<3 t plant material ha-1) mulching significantly increased soil carbon storage in the long term, albeit at lower rates than predicted. This increase was due to increases in SOM in the top-soil. As hypothesized mulch with lower C:N ratios contributed less to overall soil carbon storage, but whether this was due to differences in carbon accumulation in the short-term POM pool or long-term MOAM pool remains to be revealed by on-going isotope analysis. The high replication and detailed investigation of this long term field trial should allow us to tease out a number of processes in the carbon and nitrogen cycle and allow us recommend suitable management practices for increasing soil organic carbon stocks. 
Spatially consistent flood risk assessment for Germany
Authors: Merz Bruno , Farrag Mostafa , Guan Xiaoxiang , Guse Björn , Han Li , Kreibich Heidi , Nguyen Dung , Sairam Nivedita , Schröter Kai , Vorogushyn Sergiy
Published: February 2023

Flood risk assessments are an important basis for risk management. For larger regions, these assessments are often based on small-scale modelling, which is subsequently compiled into a large-scale picture. However, this approach neglects spatial interactions, such as decreasing risk due to upstream dike breaches, and does not provide realistic risk statements for larger regions. This paper presents the ‘derived flood risk analysis’ as an alternative approach and its implementation for Germany. A model chain consisting of hydrological, hydraulic, and damage models simulates the occurrence of extreme runoff, inundation, and direct economic damages. This model chain is driven by a weather generator that provides spatially consistent fields of climate variables. The generation of very long (several thousand years) time series with daily resolution allows the estimation of extreme runoff and corresponding damages. The consideration of the spatial relations in all model components, from the weather generator to the damage model, is able to provide consistent large-scale risk statements. This avoids the significant overestimates typical of many large-scale flood risk assessments.
Using the GTO-ECV total ozone and GOP-ECV ozone profile climate data records for analyzing global and regional trend patterns 1995-202
Authors: Coldewey-Egbers Melanie , Loyola Diego , Heue Klaus-Peter , Lerot Christophe , van Roozendael Michel , Siddans Richard , Latter Barry , Kerridge Brian
Published: February 2023

In this study, we analyze global and regional patterns of total and height-resolved ozone trends 1995-2021 based on two data records: (1) the GOME-type Total Ozone Essential Climate Variable (GTO-ECV) generated in the framework of the European Union project Copernicus Climate Change Service (C3S) and (2) the GOME-type Ozone Profile Essential Climate Variable (GOP-ECV) developed in the framework of the European Space Agency’s Climate Change Initiative (ESA-CCI) ozone project. Both GTO-ECV and GOP-ECV combine measurements from a series of nadir-viewing ultra-violet satellite sensors of the GOME-type including GOME, SCIAMACHY, OMI, GOME-2A, and GOME-2B. On top of that, GTO-ECV incorporates also GOME-2C and TROPOMI/Sentinel-5P measurements. For the retrieval of the total columns the GOME Direct Fitting version 4 (GODFIT_V4) algorithm is used, and for the retrieval of ozone profiles the Rutherford Appleton Laboratory (RAL) scheme is applied. Both the total columns and the profiles from the single sensors are merged into two homogeneous long-term gridded level-3 data records, carefully taking into account and reducing inter-sensor differences. As a final step, the ozone profile record is homogenized with respect to the well-established GTO-ECV total column record in order to achieve consistency between both products. The homogenization relies on an altitude-dependent scaling of the profiles in order to match the total column product. We apply a standard multiple linear least-squares regression to both longitudinally-resolved data records and present estimates of the long-term trend and the correlations with explanatory variables such as the Quasi-Biennial Oscillation, the solar cycle, or the El Nino-Southern Oscillation index. Of particular interest are the search for signs of ozone recovery related to decreasing amounts of Ozone Depleting Substances, the evaluation of the long-term evolution in the lower stratosphere, and the investigation of regional structures in the observed trend patterns.
Large rockfall on a small glacier - Case study of a periglacial landform formation in the Horlachtal, Stubai Alps, Austria
Authors: Fleischer Fabian , Haas Florian , Altmann Moritz , Rom Jakob , Ressl Camillo , Becht Michael
Published: February 2023

Deglaciation in high mountain areas signifies the transition from glacial to periglacial conditioned landscapes. Due to the reduced melt rate of debris coved glacier ice, these parts of the glacier might persist long after the surrounding glacier has melted, forming periglacial landforms in the post-glacial landscape. Therefore, in this case study, we examine the geomorphological development of a recent 19267 m³ ± 204 m³ rockfall from the glacier headwall on the small, low elevated Zwieselbachferner in the Horlachtal, Stubai Alps, Austria. The multi-epochal analysis is based on different remote sensing data (photogrammetrically and airborne laserscanning derived digital elevation models, orthophotos and satellite data) and covers the period from the occurrence of the initial rockfall in 2003/2004 until 2022. Results show that the headwall in this area is still very active, supplying 13 further rockfalls of varying magnitude to the debris covered glacier part during the study period. The debris cover created by rockfall, estimated to be several meters to a few decimeters thick, causes the surface elevation change of the glacier to decrease by a factor of 5 to 6 compared to the surrounding glacier. This results in the formation of a steep front and flanks, which become progressively covered and thus isolated by debris redistribution. In contrast to the surrounding glacier, whose thickness and length has strongly decreased during the study period, the mean ice thickness of the debris-covered area only decreases from 23.5 m to 21.8 m between 2006 and 2022. The extrapolation of ice thickness development shows that this part of the glacier will remain as a debris covered, ice-cored landform after the complete melting of the surrounding glacier. As glaciers melt rapidly, ELA rises and glacier headwalls become more unstable due to glacier melt and permafrost warming, we expect this process to occur more frequently in the future and in some cases to shape the appearance of formerly glaciated landscapes.
Open Methods in Operational Flood Hydrology – Considerations for researchers and practitioners
Authors: Skinner Christopher , Faulkner Duncan
Published: February 2023

The merits of open science for hydrology are firmly established, widely embedded into research culture, and increasingly adopted within operational agencies. In the UK, it is common practice now for data collected by, and/or funded by, public bodies to be made available openly, licensed for both commercial and non-commercial use, and accessible via data portals and APIs. However, these same standards are not routinely applied to the methods and models used to evaluate flood risk.This work, part of the UK’s community-led 25-year Flood Hydrology Roadmap, considered the potential role of open methods within UK operational practice. A review of the relevant literature was used to establish a definition and framework for open methods, which was refined based on consultation with practitioners. The framework was used to assess the current levels of ‘openness’ across UK practice, placing this in the context of challenges including governance, funding, and development histories. The study also considered international case studies of where open methods have been successfully implemented for hydrology and in other fields.The review was used to develop an aspirational vision for the future operational use of open methods in UK flood hydrology, identifying key barriers and recommendations to manage and overcome them. Working with artists, creative provocations have been created to further the conversation, both within hydrology and along the subsequent links in the flood risk modelling chain. The review recommendations will be summarised as considerations relevant to both researchers and practitioners.
Using a machine learning and stochastics-founded model to provide near real-time stratospheric polar vortex diagnostics based on high-latitude infrasound data
Authors: Eggen Mari , Midtfjord Alise Danielle , Vorobeva Ekaterina , Benth Fred Espen , Hupe Patrick , Brissaud Quentin , Orsolini Yvan , Le Pichon Alexis , Listowski Constantino , Näsholm Sven Peter
Published: February 2023

Acoustic waves below the frequency limit of human hearing - infrasound - can travel for thousands of kilometres in the atmosphere. The global propagation signature of infrasound is highly sensitive to the wind structure of the stratosphere. This work exploits processed continuous data from three high-latitude infrasound stations to characterize an aspect of the stratospheric polar vortex. Concretely, a mapping is developed which takes the infrasound data from these three stations as input and outputs an estimate of the polar cap zonal mean wind averaged over 60-90 degrees in latitude at the 1 hPa pressure level. This stratospheric diagnostic information is relevant to, for example, sudden stratospheric warming assessment and sub-seasonal prediction.The considered acoustic data is within a low-frequency regime globally dominated by so-called microbarom infrasound, which is continuously radiated into the atmosphere due to nonlinear interaction between counter-propagating ocean surface waves. We trained a stochastics-based machine learning model (delay-SDE-net) to map between a time series of five years (2014-2018) of processed infrasound data and the ERA5 (reanalysis-based) daily average polar cap wind at 1 hPa for the same period. The ERA5 data was hence treated as ground-truth. In the prediction, the delay-SDE-net utilizes time-lagged inputs and their dependencies, as well as the day of the year to account for seasonal differences. In the validation phase, the input was the 2019 and 2020 infrasound time series, and the model inference results in an estimate of the daily average polar cap wind time-series. This result was then compared to the ERA5 representation of the stratospheric diagnostic time-series for the same period. The applied machine learning model is based on stochastics and allows for an interpretable approach to estimate the aleatoric and epistemic prediction uncertainties. It is found that the mapping, which is only informed of the trained model, the day of year, and the infrasound data from three stations, generates a 1 hPa polar cap average wind estimate with a prediction error standard deviation of around 10 m/s compared to ERA5.Focus should be put on the winter months because this is when the coupling between the stratosphere and the troposphere can mostly influence the surface conditions and provide additional prediction skill, in particular during strong and weak stratospheric polar vortex regimes. The infrasound data is available in real-time, and we discuss how the developed approach can be extended to provide near real-time stratospheric polar vortex diagnostics.
Study of the relationship between Sunspot number and the duration of the $\sim$1.6--2.2-year period in neutron monitor counting rates
Authors: López-Comazzi Alejandro , Blanco-Ávalos Juan José
Published: February 2023

Neutron monitor counting rates show, among others, a  $\sim$ 1.6--2.2-year period. This period has been associated with a solar origin affecting the cosmic ray propagation conditions through the heliosphere. The duration of this period varies from one Solar Cycle to another.\cite{Comazzi_Blanco_2022} found the duration of the $\sim$ 1.6--2.2-year period ($\tau$) is linearly related to the averaged sunspot number ($SSN_a$) in each Solar Cycle.In this piece of research, we have analyzed this relationship. This equation shows that shorter $\sim$1.6--2.2-year periods occur during stronger cycles when $SSN_a$ is higher. Drawing on this relationship given by $SSN_a = (-130 \pm 10) \: \tau + (330 \pm 30)$, we computed $\tau$ for the cycles previous to the existence of neutron monitors (Solar Cycles 7--19). By means of the Huancayo neutron monitor spectrum we checked the validity of this equation along the Solar Cycle 19. Once the previous relationship is checked, $\tau$ for the current Solar Cycle 25 is computed giving $\sim$ 2.22 years.An internal mechanism of the solar dynamo called Rossby waves could produce these variations in the solar magnetic field  and, indirectly, in neutron monitor counting rates.The harmonic of fast Rossby waves with $m=1$ and $n=8$ fit with the detected periodicity and the variation of the solar magnetic field strength from weaker to stronger Solar Cycles could explain the different periods detected in each cycle.Finally, a solar magnetic field strength of $\sim$ 7--25 kG in the tachocline have been estimated based on the detected periodicities using the dispersion relation for fast Rossby waves. 
Glacier projections sensitivity to temperature-index model and climate downscaling parameter calibration choices
Authors: Schuster Lilian , Rounce David , Maussion Fabien
Published: February 2023

A recent large-scale glacier model intercomparison revealed a strong influence of model design choice on glacier projections. Here we examine the influence of various temperature-index mass-balance models and calibration options. With the Open Global Glacier Model (OGGM) framework, we compare the performance and projections of model options such as the use of surface-type dependent degree-day factors as well as varying temporal climate resolution (daily, monthly) and downscaling strategies (temperature lapse rates, temperature and precipitation correction). We focus on 88 glaciers with long term observations of mass-balance profiles and seasonal mass-balance, allowing us to assess the added value of using multiple mass-balance statistics in the calibration process. We find that using interannual mass-balance variability to calibrate otherwise fixed parameters generally leads to an improved representation of the mass-balance gradient, which in turn is a crucial explanatory variable for future glacier evolution. Therefore, we also find a strong influence of the calibrated temperature lapse rates on future glacier volume. Using different degree-day factors for snow, firn, and ice leads to nonlinear sensitivities, where future glacier loss depends on how the accumulation area changes compared to the calibration period. Our study illustrates the strong impact of temperature-index model choice on projected glacier volume and runoff. But it cannot clearly demonstrate the added value of additional model complexity due to the lack of independent observations.
Hyperspectral mineral mapping for underground mining
Authors: Kirsch Moritz , Mavroudi Mary , Thiele Sam , Lorenz Sandra , Tusa Laura , Booysen René , Herrmann Erik , Fatihi Ayoub , Möckel Robert , Dittrich Thomas , Gloaguen Richard
Published: February 2023

Future mining will increasingly require rapid and informed decisions to optimise ore extraction and valuation. In this context, the use of hyperspectral imaging has been proven to be effective for geological mapping in surface mining operations. The potential of hyperspectral methods in underground mining environments, however, remains underexplored due to challenges associated with illumination and surface water. Our contribution addresses this gap by evaluating different lighting setups and the effect of moisture on the spectral quality of hyperspectral data in a laboratory setup. We also compared three commercially available, visible-near infrared to shortwave infrared sensors to assess their suitability for underground hyperspectral scanning. As a demonstration, we acquired hyperspectral data from three adjacent outcrops in the visitor’s mine of Zinnwald, Germany, where rocks of a Late Variscan Sn-W-Li greisen-type deposit are exposed in representative underground mining conditions. A photogrammetric 3D digital outcrop model was used to correct for illumination effects in the data. We then estimated mineral abundance and lithium content across the mine face employing an adapted workflow that combines quantitative XRD measurements with hyperspectral unmixing techniques. Laser-induced breakdown spectroscopy was used to validate the results. While there are still challenges to overcome, this study proves that hyperspectral imaging techniques can be applied underground to yield rapid and accurate geological information. This application will pave the way for the safe, digital and automated underground mine of the future.
Why is it so difficult to reliably measure the pore pressure at the base of a fast landslide in a laboratory flume test?
Authors: Fawley Amanda , Taylor-Noonan Alexander , Tauskela Lisa , Treflik-Body Erica , Take W. Andrew
Published: February 2023

Laboratory landslide flume tests provide valuable insights into the mechanics of multi-phase granular flows within highly controlled settings. Past studies have revealed the complex fluid-particle interactions associated with saturated granular flows result in greater mobility than their dry counterparts, being notably faster, further reaching, and experiencing enhanced spreading. The ability to reliably measure the pore pressures at the base of these flows in the laboratory is critical for developing, evaluating, and validating constitutive relationships linking the effects of pore pressure to the mechanisms causing increased mobility. Unfortunately, experience has shown that two identical sensors installed in the base of a landslide flume can yield wildly different responses to the same multi-phase landslide. In this session, we explore an answer to the question “Why is it so difficult to reliably measure the pore pressure at the base of a fast landslide in a laboratory flume test?” using evidence accumulated from ten years of flume testing using the Queen’s University Landslide Flume. In particular, we explore the hypothesis that surface roughness around pore pressure sensor filter elements can influence sensor readings. A unique experimental strategy of simplifying the flow into a single fluid phase is used to validate sensor readings, prior to application in multi-phase flows. Dam-break releases of 600 kg of water at the top of the inclined flume slope are used as a parametric study to provide evidence to support the hypothesis that surface roughness significantly impacts the pore pressure recorded in high velocity flows. These results are then contrasted to observations of releases of multi-phase flows to derive best practices for the reliable measurement of pore pressure in landslide flume tests.
Hydro-geomorphic dataset of catchments across the Tibetan Plateau
Authors: guo yuhan , zheng hongxing , yang yuting , sang yanfang
Published: February 2023

The Tibetan Plateau is known as the water tower of Asia, supplying water to almost 2 billion people. As a result of the unique high-elevation terrain and atmospheric circulation, this region is severely affected by floods each year. Due to global warming in recent years, the Tibetan Plateau is experiencing more extreme precipitation events, and flood disasters are more likely to occur. However, compared with other regions in China, the Tibetan Plateau is still in its early stage when it comes to flood risk assessment and prediction because of the complex topographic conditions and a lack of gauging stations. At the same time, the unclear flood occurrence mechanism and the various flood types under monsoons and upper-level westerly winds in this region lead to strong uncertainty in the storm flood simulation.To provide support for regional-scale hydrological simulation and improve the flood risk assessment information, we produce a hydro-geomorphic unit hydrograph dataset that characterizes the rainfall and runoff response relationship in 11069 catchments across the Tibetan Plateau. More specifically, the main geomorphological features of 11069 catchments are extracted first. Then, the WFIUHs are derived from DEM and other remote sensing data combined with the empirical physical formula. Finally, the performance of the WFIUHs in hydrological simulation is assessed in several gauging catchments in this region.
A bimodal extension of the ARYA&PARIS approach for predicting hydraulic properties of structured soils
Authors: Hassan Shawkat Basel Mostafa , Dragonetti Giovanna , Comegna Alessandro , Sengouga Asma , Lamaddalena Nicola , Coppola Antonio
Published: February 2023

A new pedotransfer function (PTF) was developed based on the Arya and Paris (AP) approach to obtain Water Retention (WRC) and Hydraulic Conductivity (HCC) curves. The AP approach obtains the unimodal WRC from the Particle-Size Distribution (PSD). The proposed PTF is an extension of AP approach by incorporating the Aggregate-Size Distribution (ASD) to include the inter-aggregate pores (macropores) retention, and thus obtain the bimodal WRC. A bimodal porosity model was developed to specify the ratios of the matrix and the macropores in the overall soil porosity. Kozeny-Carmen equation was utilized to obtain the saturated hydraulic conductivity, K0, from the bimodal WRC behaviour near saturation. Then, Mualem model was applied to obtain the full HCC. To calibrate the proposed PTF, soil physical and hydraulic properties were measured from a 140-ha irrigation sector in “Sinistra Ofanto” irrigation system in Apulia Region, South Italy. Hydraulic properties came from infiltration experiments. Infiltration data were fitted using bimodal and unimodal hydraulic properties by an inverse solution of Richards Equation. The scaling parameter of the proposed PTF, αAP, was calibrated using the measured bimodal hydraulic properties. A similar calibration was carried out for the sake of comparison, in which the αAP of the classical unimodal AP was calibrated using the unimodal hydraulic properties. The proposed bimodal AP (bimAP) PTF significantly improves the predictions of the mean WRC parameters, K0 and the entire HCC, compared to the classical unimodal AP (unimAP) PTF. In addition, compared to unimAP, bimAP allows to reproduce the statistics of the hydraulic parameters (e.g., the variance) similar to those obtained from field measurements. Finally, Multiple Linear Regression (MLR) was applied to study the sensitivity of bimodal αAP to the soil textural and structural properties and the results confirmed the significant predictive effects of soil structure.
The GW-SW dynamics of a perennial dryland river in the semi-arid region, India
Authors: Raj Anukritika , Jain Vikrant , Bind Vivek Kumar , Padhya Virendra , Deshpande Rajendrakumar Dattatraya
Published: February 2023

The Groundwater-Surface water (GW-SW) interaction governed by vertical connectivity, drainage pattern, subsurface lithology, vegetation cover, and land use determines the water availability in semi-arid dryland regions. It plays a crucial role in eco-hydrology, effective water resource management and overall socio-economic development in these marginal environments. Furthermore, the perennial dryland rivers flowing through these semi-arid dryland regions undergo substantial precipitation and flow variability, thus making sustainable water management challenging. Nevertheless, an understanding of the GW-SW dynamics, its spatial variability and the processes influencing the water supply in the semi-arid perennial dryland rivers are still lacking. For this purpose, the stable isotopes of oxygen and hydrogen, in terms of δ18O, δ2H and d-excess parameters of water samples, have been used to assess the GW-SW interaction in the semi-arid perennial Mahi River basin, India. The Mahi River has a length of ~560 km and a drainage basin area of ~34k km2. In total, 53 samples of groundwater and 14 samples of river water were collected during the dry season. In a given river transect, GW samples were collected from both river banks at a distance of around 1 km and 2km, respectively. The result shows changes in GW-SW connectivity at the reach scale. The SW in the downstream and middle reaches (36 to 208km from the river mouth) is characterised by a progressive decrease in δ18O from -1.3 ‰ to -2.6‰. The decrease in the δ18O value in the middle and downstream reaches indicates the mixing of depleted GW into the river. The trend changes in the upstream reaches (208 to 491km), where the SW becomes progressively enriched in δ18O from about -2.1‰ to 0.08‰, with reach scale variability. The upstream reaches also show a decrease in d-excess value from -3.2‰ to -7.2‰, along with the increasing δ18O values suggesting enhanced evaporation of SW during the low flow conditions. The average δ18O of SW in the middle and downstream reach is -1.9 ‰, whereas the average δ18O of the upstream reach is -0.5 ‰. The slope of the GW δ18O-δ2H regression line is lower than that of the Global Meteoric Water Line (GMWL), suggesting that the GW undergoes substantial evaporation. The variability of isotopic values and mixing of GW with SW demonstrates that the river channel shows enhanced vertical connectivity for middle and downstream reaches even during the dry season. However, there is vertical disconnectivity in the upstream reaches. This study highlights the need for different management strategies for various reaches of the spatially variable and dynamic perennial dryland rivers in a semi-arid region.
Economic and environmental impacts of Southeast Asia’s energy transition strategies: a general equilibrium analysis
Authors: Ng Jia Yi , Dai Hancheng
Published: February 2023

Home to almost a tenth of the world’s population today, Southeast Asia (SEA) is one of the fastest growing regions in the world, likely to become the world’s fourth largest economy by 2030. Although SEA has received less attention compared to large nation-state GHG emitters, its climate and energy policies will come under greater scrutiny in the coming years as its contributions to global emissions grow alongside its growth in economy and energy. However, current studies on SEA energy transitions have largely been limited to qualitative assessment and lack an integrated analysis of the trade-offs between economic, environment, and energy goals. In this study, we develop a top-down computable general equilibrium model of the global economy with a focus on SEA countries and perform an integrated assessment of the economic and environmental impacts of SEA’s energy policies. Multiple scenarios accounting for different energy transition strategies of SEA countries and various levels of regional and global cooperation are considered in the assessment. Results reveal a pressing need for regional cooperation as well as a quick adoption of diverse forms of renewable energy for SEA to sustain economic growth while minimizing environmental impacts.