bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the spectral analysis of groundwater level fluctuations in a numerical model of the upper Danube catchment in Germany
Authors: Javed Rao Ali , Houben Timo , Kalbacher Thomas , Attinger Sabine
Published: February 2023

Common in-situ methods like pumping tests, slug tests and laboratory analysis reveal aquifer parameters (that is the transmissivity and storativity) that are localized and specific to the measurement location. A need for regionally valid aquifer parameters arises when setting up regional scale physically based groundwater models. The models would help water resource managers to plan and predict the quality and quantity of groundwater resources, thus supports decision making as well as sustainable fresh water supply. A study from Houben et al. 2022 indicate that regional aquifer parameters can be obtained by analysing the frequency content of groundwater level time-series. Their work builds upon a semi-analytical solution for the groundwater head spectrum stochastically derived from the Boussinesq equation evoking the Dupuit assumptions. They found that the solution can be used to infer the transmissivity and storativity from groundwater level fluctuations and validated their hypothesis in simplified numerical environments of different complexity.In this work, we extended the numerical experiments and applied the semi-analytical solution in homogeneous and heterogeneous 2D (x-y-plane) aquifers as well as in a complex numerical 2D (x-y-plane) model of the upper Danube catchment. We tested the hypothesis that certain locations can reveal regional aquifer parameters. In a homogeneous simulated model, the semi-analytical solution reveals effectively the model input parameters which serves as a proof-of-concept. In a heterogeneous numerical model, the obtained parameters show the complex interplay between zones of different permeability. The effects of high permeable zones can be observed on the low permeable zones which are further apart and vice versa. The obtained parameters were in the range of the model input parameters and followed the trend of the input parameters along the direction of flow. In the model of the upper Danube the obtained parameters were systematically larger than the input parameters. The shift in the obtained parameters was attributed to a violation of the assumptions of the semi-analytical solution. Thus, the complexity of model leads to a breakdown of the semi-analytical solution in some areas. Analyses on a sub-catchment scale revealed that when the assumptions of the analytical solution are met, the obtained parameters reflect the effective parameters.
Adaptation of open-source global optimization software to the process of iterative inversion of resistivity well logs
Authors: Wilkosz Michał
Published: February 2023

In the past decades, boreholes were drilled all over the world for the purpose of hydrocarbon prospection. Data from these boreholes are a very valuable resource, that can be used in current geological, geothermal and hydrogeological studies. Since the process of drilling is both expensive and disturbing to the environment the possibility of incorporating data that already exists in the current studies is always worth consideration. However, in the case of older boreholes quality of data is not on par with modern standards which limits its usefulness, especially in the case of data from boreholes drilled in thin-bedded rock formations.Resistivity logs are one of the main logs used both in hydrocarbon prospection and other applications such as geological, geothermal and hydrogeological studies. Resistivity logs measured by older generations of logging tools are characterized by significantly lower vertical resolution in comparison to logs measured by newer logging tools which affect the quality of the interpretation. However, the information averaged in the process of logging can be partially restored in the process of iterative inversion.The focus of the presentation is on the utilization of open-source global optimization software in the process of inversion of resistivity well logs. Since inverse problems encountered in geophysics tend to be on the difficult side, relatively simple optimization schemas that often can be found in open-source software are not always giving good results. Therefore, in the presentation, a few methods that allow adapting those algorithms to the problem of inversion of well logs are discussed. The performance of the inversion procedure is validated on synthetic data and real data from the borehole where resistivity logs were measured by different generations of logging tools in the same depth intervals, which allows for comparison of the inversion results to logs measured by modern equipment. The research was funded by the National Science Centre, Poland, grant number 2020/37/N/ ST10/03230.
NW Pacific-Panthalassa intra-oceanic subduction during Mesozoic-Cenozoic times from mantle convection and geoid models
Authors: Wu Jonny , Lin Yi-An , Colli Lorenzo
Published: February 2023

The plate tectonic history of the Pacific Ocean and its predecessor ocean, Panthalassa, are challenging regions on Earth to reconstruct during the Mesozoic-Cenozoic eras. More than 95% of Pacific-Panthalassa crust has been subducted into the Earth’s interior since the Jurassic, and this has created extensive (>9000 km length) plate reconstruction gaps between the Pacific and Eurasia/Laurasia. Here we build four contrasted NW Pacific-Panthalassa global plate reconstructions and assimilate their velocity fields into the global geodynamic models using the code TERRA: Andean-style subduction along East Asia following the corrected ‘R’ Matthews et al. (2016); and, three models that include intra-oceanic subduction within Pacific-Panthalassa with increasing tectonic complexity.   We compare our predicted present mantle structure, synthetic geoid and dynamic topography to Earth observations. P-wave tomographic filtering of predicted mantle structures allows for more explicit comparisons to global tomography.All three plate reconstructions that include NW Pacific-Panthalassa intra-oceanic subduction fit better to the observed long-wavelength geoid and residual topography.  Correlations between modeled and imaged mantle structure do not systematically favor any single model, and this is attributed to limited tomographic resolution within the central Pacific mantle relative to variability in our modeled mantle structures.  Taken together, our results robustly show the likelihood of intra-oceanic subduction within NW Pacific-Panthalassa.  This presents a challenge to popular plate models of Andean-style subduction along East Asia, which are deeply-embedded into most published plate tectonic, geodynamic and geologic studies.  Our geodynamic models predict significant (>2000 km from Mesozoic to present) southeastwards lateral slab advections within the lower mantle that would confound ‘vertical slab sinking’-style restorations of ancient subduction zones.  Plate reconstructions that can better incorporate intra-oceanic subduction within Pacific-Panthalassa may improve our knowledge of past global CO2, mantle flow, and dynamic topography histories.
Coastal Erosion Processes along Cape Cod Bay, MA, USA
Authors: Warner John C. , Brothers Laura , Himmelstoss Emily , Sherwood Chris , Foster Dave , Farris Amy
Published: February 2023

Ocean-facing shorelines experience morphological changes on many temporal and spatial scales in response to various processes such as wave breaking, overwash, as well as wave- and wind-driven currents. The nature of coastline response can vary due to several factors, including the underlying sub-bottom stratigraphic structure, surficial sediment type, and local vegetation cover, among others. These eco-geomorphic changes are significant for both understanding coastal community hazards and infrastructure planning for short- and long-term shoreline stability. Cape Cod Bay, MA, is a semi-enclosed embayment in the northeastern United States, open on the north to the Gulf of Maine. Typically, the coastline experiences the largest impacts from strong Nor’easter storms that occur in the late fall or winter months. Some sections of this coastline are affected more severely than others. We investigate the processes that cause spatial variability of coastal response to storm impacts by using geophysical surveys, shoreline-change analysis, and numerical modeling. We simulated the Gulf of Maine and Cape Cod Bay from Jan – April, 2021, using the COAWST modeling system, including ocean, wave, infragravity wave (InWave), and sediment transport models, with an initial focus using a uniform seafloor sediment distribution. This time period included several strong Nor’easter events. The modeling used several grids to simulate bay-scale (order 100’s meters for Cape Cod Bay) down to nearshore-scale (order several meters for an 18km section of coast) processes. Bay-scale results produce storm-driven circulation of landward surface flows and seaward near-bottom currents, alongshore sediment fluxes, and sediment convergences at regional shoals. Nearshore modeling identified the largest impact from storm events when the surge, tide, and strongest waves all coincided. Analysis of the InWave model results reveal localized zones of increased wave heights, spaced along the 18km section of coast, due to bathymetrically induced alongshore convergence of wave energy flux. These locations correlate with observed regions of increased erosion and severe coastal impacts. Modeled and observed shoreline-change demonstrate locations of high correlation but the model does not capture all the variability. Computed net sediment fluxes for the modeled time period along the coast agree with regional sediment flux observations.  
Machine learning based wheat yield early estimation using satellite-derived spectral indices, weather data and input fertilizers
Authors: khechba keltoum , laamrani ahmed , sebbar badreddine , chehbouni abdelghani
Published: February 2023

Remote sensing data is crucial in modern agriculture, particularly to estimate wheat yields over large areas quickly and accurately. This is especially important in Morocco, where drought has led to low wheat production in the 2022/23 marketing year. This study aimed to evaluate variations in wheat yield within Moroccan fields. Four spectral indices were extracted from Sentinel-2 imagery (NDVI, GCVI, EVI and SATVI) for the agricultural season of 2020 and 2021, as well as data on total precipitation, maximum and minimum air temperatures, and total NPK fertilizer inputs. Three machine learning models were used for the analysis: Multiple Linear Regression (MLR), Random Forest (RF), and Extreme Gradient Boosting (Xgboost). The results showed that the non-linear models (RF and Xgboost) performed better than the linear model (MLR). The best performing algorithm was found to be Xgboost, with an R² value of 0.75 and a root mean square error of 689 kg.ha-1 when only using spectral indices and climate data, and a root mean square error of 566 kg.ha-1 when adding total NPK fertilizer data. The use of remote sensing indices, climate data, and NPK inputs with a machine learning technique was found to be effective in estimating wheat yields and can help to fill gaps in missing data.
Three-dimensional pathways of Saharan dust export over the North Atlantic during the CADDIWA field campaign
Authors: Cuesta Juan , Flamant Cyrille , Gaetani Marco , Delanoë Julien , Chaboureau Jean-Pierre , Menut Laurent , Formenti Paola
Published: February 2023

Massive amounts of desert dust uplifted over the Sahara are exported over the North Atlantic. They play a major environmental role over this region, impacting the Earth radiative budget, atmospheric dynamics and thermodynamics, cloud properties, atmospheric composition, and biogeochemistry. These multiple impacts of Saharan dust can also affect the evolution of mesoscale convective systems (MCS) formed over West Africa that may lead to the formation of tropical cyclones over the North Atlantic. A better understanding of these aspects, also influenced by African Easterly waves, is the primary objective of the “Clouds-Atmospheric Dynamics-Dust Interactions in West Africa - CADDIWA ” field experiment that took place on September 2021.  The current presentation will provide a comprehensive description of the three-dimensional (3D) distribution of Saharan dust and its pathways of export over the North Atlantic during CADDIWA. This will be analysed with respect to the location and evolution of the MCS travelling over the region. This characterisation will be done using a suite of observations which will be compared with dust simulations. The objective is to analyse the difference in terms of abundance and 3D distribution of dust between the cases where MCSs lead to cyclogenesis and those not evolving that way.The ensemble of datasets describing the Saharan dust distribution will be inter-compared and their consistency verified. Twice-daily satellite thermal infrared hyperspectral measurements from IASI will be used to document the 3D distribution of desert dust for cloud-free conditions using the AEROIASI approach (Cuesta et al., 2015; 2020). Further details will be provided by nadir-pointing lidar measurements from AEOLUS and CALIOP space sensors, and from the RALI airborne instruments, in terms of transects of aerosol profiles and winds. In addition to aerosol backscatter profiles, AEOLUS and LNG-RALI will provide aerosol extinction profiles, provided their high spectral resolution capabilities. Observations from MODIS and VIIRS of aerosol optical depth will inform on the horizontal distribution of desert dust. Airborne in situ measurements of the size distribution and intensive optical properties of desert dust, such as the angstrom exponent, will be compared to those used as a priori properties of dust within the satellite dust retrievals (particularly for IASI). These satellite and airborne measurements will be confronted with simulations from the Meso-NH and WRF-CHIMERE, contributing with an all-sky and hourly 3D description.
Should we find out new mathematical strategies to model the Free Core Nutation?
Authors: Belda Santiago , Karbon Maria , Escapa Alberto , Puente Víctor , Modiri Sadegh , Ferrándiz José M.
Published: February 2023

Consideration of the Free Core Nutation (FCN) is required to improve the modelling of the Celestial Pole Offsets (CPO) since it is the major source of inaccuracy or unexplained time variability with respect to the current IAU2000 nutation theory. The FCN is a free mode related to the non-alignment of the rotation axis of the core and of the mantle. It can only be measured/detected by Very Long Baseline Interferometry (VLBI). IERS Conventions (2010) recommends an empirical FCN model of Lambert (2007). However, other alternative models are available today (e.g. Krásná et al. 2013; Malkin 2013; Belda 2016). All these models are based on the sliding window least-squares fit method, assuming a constant period of about -430 solar days.In our previous studies, we evidenced that the period of the FCN could vary with time. Due to this FCN period variability, the conventional empirical FCN models would not be completely correct. Therefore, should we find out new mathematical approaches/strategies to model the FCN?In this study, a new mathematical strategy is examined. We utilized the Whittaker smoother to extract the desired signal from the CPO series obtained from VLBI. This technique tends to behave as highly adaptive and versatile fitting algorithms and can thus replace conventional FCN models. Apart from that, it is extremely fast, gives continuous control over smoothness with only one parameter (lambda), interpolates automatically, and allows fast leave-one-out cross-validation. The preliminary assessment using the observed nutations derived from VLBI analysis demonstrated the potential of Whitaker smoother as an optimum algorithm to successfully reconstruct the FCN signal with more efficient performance to retrieve reliable patterns. This analysis could bring us significantly closer to meeting the accuracy goals pursued by the Global Geodetic Observing System (GGOS).
Global Sources of Moisture for Atmospheric Rivers over Antarctica
Authors: Datta Rajashree , Herrington Adam , Trusel Luke , Schneider David , Nusbaumer Jesse , Yin Ziqi
Published: February 2023

 The quantity and characteristics of atmospheric rivers over Antarctica, which import heat and moisture towards the continent, are a major source of uncertainty in future sea level rise estimates. We employ a new variable-resolution grid over Antarctica, using CESM2 (VR-CESM2), which balances the extensibility of a GCM with the high computational costs of a high-resolution climate model. This setup uses observed sea surface temperature and sea ice concentration, implements moisture-tagging (linking precipitation to a moisture source region on the globe), and produces high spatial and temporal resolution atmosphere and ice sheet surface outputs, which can be used to detect atmospheric rivers and to estimate their impact.As a baseline for experiments testing the relative importance of large-scale drivers, we first quantify, over an idealized 10-year period, the global sources of moisture and the portion of total precipitation that reaches the ice sheet during large-scale vs atmospheric river events (and their associated synoptic characteristics). Beyond this baseline, we will use this setup to perform initial test scenarios assessing the relative impact of reduced sea ice combined with enhanced ocean heat at lower latitudes.
The Impact of Solar Radiation Modification on Earth System Tipping Points and Threshold Free Feedbacks
Authors: Futerman Gideon , Wieners Claudia
Published: February 2023

The modification of the climate by Solar Radiation Modification (SRM) could be a potentially important human-Earth System interaction in the Anthropocene, having potentially beneficial and adverse impacts across climatic and human indices. SRM would likely interact with Earth system resilience in many ways, with our paper exploring SRM’s interaction with Earth System tipping point which has been extremely underexplored in the literature thus far.SRM would likely be able to reduce global mean surface temperature quickly, although its broader climate imprint, especially on precipitation and local climatic conditions, is not the same as reversing greenhouse gas emissions. Its cooling effect suggests that SRM can help stop us from hitting those tipping elements that are most temperature-dependent, while the situation is more complex for tipping elements which strongly depend on other factors such as precipitation or regional climate changes. This more complex picture could have important implications for the role (or lack of) that SRM could and ought to play in improving Earth system resilience in the Anthropocene.We review the available literature about the influence of SRM on the tipping elements and threshold free-feedbacks identified by McKay et al. (2022), as well as reviewing the impact of SRM on relevant climatic conditions that could contribute to tipping of each element, to give an assessment of the potential beneficial or adverse impact of SRM and identify key uncertainties and knowledge gaps. We will also briefly assess how these impacts may differ with different methods of deployment and with the termination of SRM.
Employing machine learning pickers for routine global earthquake monitoring with SeisComP: What are the benefits and how can we quantify the uncertainty of picks?
Authors: Tilmann Frederik , Bornstein Thomas , Saul Joachim , Münchmeyer Jannes , Beutel Moshe
Published: February 2023

Recent years have seen the development of several very powerful machine learning pickers for P and S waves. The recent development of the SeisBench platform (https://github.com/seisbench/seisbench) in combination with mixed regional teleseismic benchmark datasets published by the NEIC (USGS) and GEOFON (GFZ Potsdam) enabled the retraining of the most popular picker neural network models (PhaseNet and EQTransformer) optimised for global monitoring applications in the benchmark study of Münchmeyer et al (2021, J. Geophys. Res.).  In this contribution we introduce a module scdlpicker, which connects SeisBench to SeisComP (https://www.seiscomp.de/)  through a client submodule, which listens to new event detections from the regular SeisComP automatic detection system and triggers repicking of those events with any picker implemented in SeisBench, using the improved picks to trigger a relocation. The machine learning picks are subsequently available within the SeisComP GUI in case further manual refinement or checking is desired. We demonstrate application of this system with the GEOFON global earthquake monitoring service (https://geofon.gfz-potsdam.de/eqexplorer), evaluating the benefits of using the machine learning picker with respect to the conventional workflow relying on traditional pickers with respect to timeliness of reporting earthquakes and reduction of manual work load, and improvement in the number of high quality picks available for each event. The quantification of the uncertainty of machine learning picks is important when weighing the contribution of different picks in many location algorithms, yet this information is not readily available from machine learning pickers. They do return, however, a characteristic function (nominally the confidence in the pick), whose properties might correlate with the uncertainty of the pick. We will show whether and how the picking uncertainty correlates with properties of the characteristic function. 
Skill assessment of sub-seasonal forecasts of different atmospheric variables related to extreme precipitation events over Italy
Authors: Scott Wazita , Gaetani Marco , Fosser Giorgia
Published: February 2023

Extreme precipitation events (EPE), especially those leading to floods and landslides, are devastating to society. Predicting these events in advance can help disaster managers to carry out plans of action to respond effectively to any oncoming adverse events. Sub-seasonal forecasts, which aim to predict the weather with 2 weeks to 2 months in advance, can help to provide valuable and actionable information to disaster managers. Given the potential usefulness to end users, it is vital to assess the skill of sub-seasonal forecasts in predicting EPEs. However, given that precipitation is known to be a difficult variable to predict, the lead time at which forecasts are skilful may be limited. This study, therefore, aims to assess at which lead time sub-seasonal forecasts of atmospheric drivers of EPEs are skilful.The study investigates the skill of the European Centre for Medium-Range Weather Forecast (ECMWF) sub-seasonal reforecast in predicting EPE over Italy from 2001 to 2020. A total of 100 EPEs are used as case studies. The variables evaluated are total precipitation, mean sea level pressure, geopotential height at 500 hPa and specific humidity at 850 hPa. Variables are averaged over the 5 days surrounding the date of the EPE. ERA5 is used as the reference dataset. Both deterministic and probabilistic metrics are used to assess the skill of the reforecast.Results show that the skill for precipitation is limited to the first two weeks. Nevertheless, the ECMWF sub-seasonal product is skilful in predicting the atmospheric fields associated with the selected EPEs, such as MSLP and geopotential height, showing both reliability and discrimination beyond two weeks.
Machine learning-based peak flow estimation for improved flood resilience of transportation infrastructure
Authors: Pokharel Sudan , Roy Tirthankar , Admiraal David
Published: February 2023

Accurate and timely prediction of peak flow in streams is essential for transportation safety as these estimates can help transportation authorities implement precautionary measures (e.g., road closures, diversion, emergency routes, transportation planning, flood impact assessment, etc.) well ahead of time to mitigate the impacts of flooding on transportation. Often in practice, flow quantiles are estimated from catchment and climate attributes using simple methods such as linear regression, which overlooks the more complex nature of relationships between variables, potentially leading to errors and uncertainties in the estimates that can trickle down to engineering design. Here, we will discuss findings from our ongoing work on accurate estimation of peak flow using machine learning algorithms. The methodology involves a two-step process. First, k-means clustering is implemented to identify regions that have similarities in the mean annual runoff. Second, Random Forest is implemented to map a wide range of climate and catchment features to flow quantiles in each cluster. To assess the effectiveness of this approach in increasing transportation resilience, we will show how the peak flow estimates from this new approach compare with the estimates from the existing approach followed by the Nebraska Department of Transportation and explore the potential of these new estimates to be used for operational purposes for flood-related decision-making in the context to transportation infrastructure.
Effect of aerosol changes on regional climate in East Asia
Authors: Lee Seungun , Park Rokjin , Yeh Sang-Wook , Jeong Yong-Cheol
Published: February 2023

This study investigates the effect of aerosol changes on regional climate in East Asia. Especially, we focus on the recent decreasing trend of aerosol concentrations in China from 2011 to 2018. We conduct climate sensitivity simulations using the Community Earth System Model (CESM) atmospheric general circulation model (AGCM) with observed monthly sea surface temperatures (SST) and sea ice concentrations (SIC) and coupled general circulation model (CGCM) with its own predicted SST and SIC from the coupled ocean and sea ice models. We prescribe the observed monthly aerosol optical depths from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Terra and Aqua satellite for the base simulations and period-averaged monthly aerosol optical depths for the sensitivity simulations. Comparisons of 50 ensemble averages between the base and sensitivity simulations for the AGCM and CGCM models show that the decreasing aerosols in East Asia warm up the region due to increased net shortwave radiation. We also found that the CGCM simulations show much stronger and more extensive warming in East Asia due to decreasing aerosols than the AGCM simulations, implying the importance of the aerosol-ocean-atmosphere feedback.
Trainable geological model under the framework of model-based gravity inversion
Authors: Liang Zhouji , de la Varga Miguel , Wellmann Florian
Published: February 2023

Uncertainties in geological modeling have drawn increased attention in recent years. This is due to the fast-evolving computational power and more demanding evaluation of the modeling procedure.However, these uncertainty quantifications (UQ) often face high dimensionality. Advanced mathematical methods have been developed to significantly improve the efficiency of the UQ process. Still, many of the methods require not only the forward evaluation of the quantity of interest but also the partial derivative information to guide the posterior exploration (e.g., HMC, SVGD). Differentiable geological modeling methods have been introduced and have become an appealing tool to efficiently evaluate the partial derivatives w.r.t. the input parameters using Automatic Differentiation (AD) techniques.To successfully apply AD to geological modeling several challenges need to be addressed. One of these challenges is the aliased effect due to discretization. In this work, we will introduce a method to generate a trainable geological model under the framework of gravity inversion using the implicit geological modeling method. We present a smooth-step function in the scale value domain and adopt an order-reduction method to provide a visual evaluation of the trainability of the generated model. This work provides the fundamental step to the application of advanced derivative-informed UQ and optimization methods.
Teaching Geosciences through practical activities to enhance global citizenship education in schools with a high dropout rate
Authors: Piegari Ester , Camanni Giovanni , Flocco Daniela , Milano Maurizio , Mondillo Nicola , Riccardi Umberto
Published: February 2023

Most students living in disadvantaged areas do not trust that their school education will have much bearing on their future and become disaffected from school as early as in lower secondary school.We here report the results of teaching Geosciences through several practical activities carried out in suburban schools characterized by a high dropout rate. The lectures were given in the framework of the STEM project Next Land, which has the overarching goal of instilling interest towards scientific topics into young students and promoting the role of scientific education for sustainable development.We propose a sequence of four laboratory activities on the subject of natural calamities (e.g. earthquakes and tsunamis), which are based on the use of both manual and IT skills.The didactical experimentation has been conducted on 21 seventh-grade classes (age ~12) involving about 350 students from the area of Naples (Southern Italy). The final aim of the teaching is to test the potential of the Geosciences in generating attitudes and behaviours of solidarity and responsible global citizenship.All the proposed activities try to make students aware that they are part of a connected global system, therefore through these lectures we attempt to help these young students to put in perspective their local reality in a larger one.
Per- and Polyfluoroalkyl Substances (PFAS): Concentrations and Deposition in Precipitation
Authors: Shafer Martin , Gay David
Published: February 2023

An increasing body of evidence documents measurable levels of a broad range of PFAS compounds in precipitation - which translate into substantial deposition loads to terrestrial and aquatic resources. In many environments these atmospheric deposition fluxes can represent the dominant source of PFAS – however, very large gaps in our understanding of atmospheric sources and processing, and deposition fluxes of PFAS remain. To address these issues the University of Wisconsin-Madison Wisconsin State Laboratory of Hygiene (WSLH) and the WSLH managed National Atmospheric Deposition Program (NADP), initiated a program to evaluate the efficacy of the US NADP National Trends Network (NTN) for assessment of wet-deposition of PFAS and provide novel new data on levels of PFAS in precipitation across the US.  Dedicated experiments with a diverse suite of 34 PFAS compounds addressed system blanks and stability of the PFAS species in the NTN precipitation collectors. A robust standardized protocol was promulgated for PFAS wet-deposition measurements using the NADP-NTN infrastructure and analytical tools at the WSLH.We have now applied this protocol in several studies, including in an intensive 5-month study in 2020 at NTN sites across Wisconsin, USA (Pfotenhauer et al., 2022), and in an on-going large-scale nationwide monitoring effort at 10 NTN sites initiated in 2020 and supported by the US Environmental Protection Agency-Office of Research & Development (EPA-ORD).  In the Wisconsin study, 91 precipitation samples, along with an array of QA/QC samples were collected from 8 NTN sites across Wisconsin, and analyzed for 34 PFAS compounds. Concentrations of individual PFAS compounds were generally less than 1 ng/L, however, summed PFAS concentrations ranged from 0.7 to 6.1 ng/L with a median of 1.5 ng/L. Perfluoro carboxylates (PFCAs) were detected most frequently and constituted an average of 83% of the total PFAS mass. Daily flux values ranged from 1.3 to 47.4 ng/m2/day with a median of 5.7 ng/m2/day. Differences in the PFAS fingerprints were observed among the 8 sampling sites, reflecting local sources.
Use of image velocimetry techniques on citizen videos of the November 2021 flooding event flows in Merritt, British Columbia
Authors: Yang Jason J. S. , Weijs Steven V.
Published: February 2023

In November 2021, an atmospheric river swept the Pacific Northwest region, causing one of the costliest natural disasters in Canadian history. Among others, the Coldwater River in Merritt, British Columbia caused widespread flooding on November 15th, 2021, resulting in extensive damage to the infrastructure and total evacuation of the residents.Estimating the magnitude of this flood is difficult, as it damaged the local flow monitoring station and altered the surrounding landscape. However, parts of this flooding event, including the flow close to its peak, were filmed by local residents using mobile devices or drones. Though with significant perspective distortion and imprecision, they still provide valuable information on the extreme flow event, which would have otherwise been lost or neglected. The objective of this study is to apply image velocimetry techniques to these videos, with limited resources and geodata, for reconstructing surface velocities and discharges during the flood.The analysis method consists of using LSPIV and Farneback optical flow on the original clips where possible. Objects are identified in the videos, then geolocated or surveyed after the flood, for rectification of raw velocities. This allows multiple iterations, accounting for uncertainties in the rectification parameters. Discharges are then calculated using surveyed or reconstructed transects, and water surface elevations estimated from the video frames.Preliminary results of both methods will be presented and compared on the use of lens distortion correction, different contrast enhancement block sizes, and interrogation area or filter sizes. Validations of the calculated discharges against flow observations from the Water Survey of Canada will also be included.
Modeling sediment transport in vegetative areas with a two-phase flow approach
Authors: Mullarney Julia , Chassagne Rémi , Nelli Vinay
Published: February 2023

In vegetated areas, water flow and sediment transport are highly influenced by their interactions with vegetation. The induced vegetation drag force reduces the water flow velocity but increases the TKE (turbulent kinetic energy). Recent laboratory experiments of flow within array of rigid cylinders have shown that the fluid bed shear stress, and consequently the sediment transport rate, are correlated with the TKE instead of with the depth-average velocity.In this context, modeling sediment transport in vegetated areas represents a major challenge for the prediction of the geomorphic evolution of coastlines. In this study, a three-phase flow model for sediment transport in vegetation is presented. The governing equations are obtained from a double averaging procedure: a spatial and turbulence (Favre) averaging. The model is based on the sedFOAM solver, in which the particle phase is represented as a continuum with constitutive laws based on the kinetic theory of granular flows and a turbulence model is required for the fluid phase. The vegetation is represented as a passive phase which interacts with the other phases through a drag force.First, simulations without sediment are performed and compared with measurements from existing laboratory experiments. The model demonstrates a very good capacity to predict the fluid bed shear stress and the turbulence intensity. The model is also compared with new high-resolution field data (Cook’s beach, New-Zealand). Secondly, sediment transport simulations are performed and compared with laboratory experiments. The results of the model are used to analyze the physics of sediment transport within vegetative regions and to discuss the next necessary steps toward larger-scale modeling.
The highly advanced ICEBEAR-3D E-region coherent imaging radar
Authors: Hussey Glenn , Lozinsky Adam , Pitzel Brian , Ivarsen Magnus , Galsechuk Draven , Huyghebaert Devin , McWilliams Kathryn , St. Maurice Jean-Pierre
Published: February 2023

ICEBEAR (Ionospheric Continuous-wave E-region Bistatic Experimental Auroral Radar) employs advanced software defined radio (SDR) and aperture synthesis radar imaging to produce unambiguous high resolution (1--2~km) 3-dimensional (range, azimuth, elevation) coherent E-region observations.  ICEBEAR-3D operates in the VHF at 49.5~MHz observing the auroral zone of the ionosphere from western Canada (58N, 106W geographic).  The receiver antenna array was re-configuration in 2019 to a non-uniform co-planar T-shaped double interferometer layout to complete the ICEBEAR design and allow for unambiguous, highly detailed, high-resolution coherent radar E-region observations.  We present the antenna array re-configuration; the novel and advanced synthesis aperture radar imaging technique; a low elevation angle accuracy and reliability solution; validations and calibrations of ICEBEAR-3D using celestial radio sources (Cygnus A) and interferometer closure angles; as well as some initial E-region and meteor trail observations and analysis.
Frictional-viscous flow and the aseismic-seismic transition at shallow depths
Authors: Boulton Carolyn , Niemeijer André , Mizera Marcel , Little Timothy , Müller Inigo , Ziegler Martin , Hamers Maartje
Published: February 2023

During the interseismic period of an earthquake cycle, creeping patches and locked asperities on crustal faults control the distribution of accumulated elastic strain and thus their seismic potential. Yet the frictional and frictional-viscous processes that facilitate creep on shallow crustal faults, such as near-trench subduction zone décollements, remain poorly understood. At mid-to-low latitudes, calcareous sediments are important subduction zone input materials. Compared with siliciclastic lithologies, calcareous rocks more readily accommodate strain aseismically via crystal plasticity and diffusive mass transfer processes at low temperatures and pressures in the upper crust. Along the Hikurangi Subduction Margin of New Zealand, accretionary prism uplift has exposed the Hungaroa fault zone, an inactive thrust fault developed within fine-grained, calcareous sedimentary rocks.
In this research, we present observational and theoretical evidence that the Hungaroa fault zone accommodated deformation primarily by distributed aseismic creep within a ~33 m-wide fault core.  Syntectonic calcite vein clumped isotope thermometry and maximum differential stress estimates indicate that deformation took place at 2 to 4 km depth. We model the fault zone rheology assuming diffusion-controlled frictional-viscous flow, with deformation at strain rates ≤10-9 s-1 able to have taken place at low shear stresses (τ <10 MPa) given sufficiently short diffusion distances (d <0.1 mm), even in the absence of pore fluid overpressures. Critically, fault zones with diffusion-controlled frictional-viscous flow rheology can exhibit spatially and temporally variable strain rates if grain-scale and fracture-scale processes change the diffusion distance. Thus, the shallow (up-dip) limit of the seismogenic zone is not a simple function of temperature in fault zones governed by a frictional-viscous flow rheology.
On the mesoscale structure of CMEs at Mercury's orbit: Parker Solar Probe and BepiColombo observations
Authors: Palmerio Erika , Carcaboso Fernando , Khoo Leng Ying , Sánchez-Cano Beatriz , Nieves-Chinchilla Teresa , Lario David , Rivera Yeimy , Pal Sanchita , Stevens Michael L. , Salman Tarik M. , Weiss Andreas J. , Lee Christina O. , Whittlesey Phyllis L. , Heyner Daniel
Published: February 2023

On 15 February 2022, an impressive filament eruption was observed off the solar eastern limb from three remote-sensing viewpoints, namely Earth, STEREO-A, and Solar Orbiter. Apart from representing the most-distant observed filament at extreme ultraviolet wavelengths—captured by Solar Orbiter's field of view extending to above 6 Rs—this event was also associated with the release of a fast (~2200 km/s) coronal mass ejection (CME) that was directed towards Parker Solar Probe and BepiColombo.Parker Solar Probe and BepiColombo were separated by 3° in latitude, 4° in longitude, and 0.03 au in radial distance at the time of the CME-driven shock arrival at the two spacecraft. The relative proximity of the two probes to each other and to the Sun (~0.365 au) allows us to study the mesoscale structure of CMEs at Mercury's orbit for the first time. We analyse similarities and differences in the magnetic structure of the CME ejecta measured at the two locations, as well as other properties such as shock/sheath characteristics, pitch-angle distributions, and impact of the interaction between the ejecta and its surroundings. Finally, we contextualise our findings within the current discussions on the need to investigate solar transients via spacecraft constellations with small separations, which have been gaining significant attention during recent years.
Lifecycle of the 21 July, 2020 Shaziba landslide investigated using multi-source remote sensing observation
Authors: Wang Wandi , Motagh Mahdi , Mirzaee Sara , Li Tao , Zhou Chao , Tang Hui , Roessner Sigrid
Published: February 2023

Shallow landslides and debris flows triggered by high-intensity continuous precipitation are widespread in the  western part of Hubei province, China. Studies have also shown that most of the landslides in western Hubei belong to the category of  slow-moving landslides that impact infrastructures and can eventually turn into catastrophic failures. Although many landslides cannot be prevented, some possible scientific early warning detection and landslide evolution analysis before and after the failure can help in risk management practices. Under favorable conditions, optical and Synthetic Aperture Radar (SAR) satellite remote sensing data  play a key role in robust characterization of life cycles of slow moving landslides. In this study, we utilized various SAR and optical sensors to investigate kinematic evolution and volumetric change related to the 21 July, 2020, the Shaziba landslide that occurred in Mazhe County, Hubei Province, China (N 30° 36′ 5′′, E 109° 29′ 85′′). The catastrophic failure happened  following a record precipitation that reached a historical peak of 442.3 mm in the month of failure, exceeding the previous historical peaks in the same month. This landslide caused the collapse of more than 60 homes, the destruction of village roads, the destruction of electrical infrastructure and agriculture, the evacuation of more than 1000 individuals, and the pollution of Enshi City's water supply source with silt. Fortunately, there were no fatalities. The pre-failure ground deformation using Sentinel-1 data from June 2016 to July 2020 indicates ground motions at average rates of 30 mm/yr. The co-failure estimation from Planet and Sentinel-2 shows that horizontal displacements in the eastern part of the landslide up to 30 m. The landslide eroded to 4.93 million m3 meters, with DEMs generated from TanDEM-X data before and after the failure. The post-failure ground deformation analysis performed using Sentinel-1 and TerraSAR-X data between August 2020 to July 2021 indicated the instability of the marginal scarps above the crown of landslide and eastern, with an LOS displacement rate of approximately -30 - -10 mm/year. 
UK crop yields towards the end of the 21st century under a worst case RCP 8.5 climate change scenario: Using the UKCP18 convection permitting model to drive T&C-Crop, a recently developed process-based ecosystem model with a novel agricultural module.
Authors: Buckley Paules Jordi , Paschalis Athanasios , Fatichi Simone , Warring Bonnie
Published: February 2023

Climate change is increasingly affecting crop production, boosting crop yields in some parts of the world whilst decreasing them in others. The UK is a prime, albeit condensed example of this variability. This is due to the UK’s noticeable regional heterogeneity when it comes to present and projected future climate. Subsequently, the impact of climate change on UK crop yields is likely to be spatially non-uniform as well as crop-specific. Thus, any blanket approach to agricultural adaptation in light of climate change is likely to be sub-optimal. In light of this, we here propose a quantitative assessment to support regional agricultural policy. We examine how crop-specific yields (e.g., Maize, Wheat, Potatoes…) are likely to vary spatially in the UK towards the end of the 21st century under a worst case RCP 8.5 climate change scenario. To achieve this we use the latest generation convection permitting model projections offered by the Met Office (UKCP18) which allow for climate projections at ecohydrological relevant spatiotemporal scales. These climate projections are then used to drive T&C-Crop, a recently developed process-based ecosystem model with a novel agricultural module.
The Venice Lagoon foreshadows the fate of coastal systems under climate change and increasing human pressure.
Authors: D'Alpaos Andrea , Finotello Alvise , Tognin Davide , Carniello Luca , Marani Marco
Published: February 2023

Coastal systems are among the most economically valuable and highly threatened systems on Earth. They provide a wide range of valuable ecosystem services but are severely threatened by climate changes and increasing human pressure. We consider and analyze the Venice Lagoon as a paradigmatic case representative of the coevolution of man and landscape, of natural processes and human agency. The history and fate of Venice Lagoon, the largest brackish waterbody in the Mediterranean, are tightly intertwined with those of the City of Venice. We show, through an interdisciplinary approach combining field observations, remote sensing, laboratory analyses, and mathematical modeling, that increasing anthropogenic pressure, coupled with the effects of natural processes exacerbated by climate changes, has led to an accelerated morphological deterioration of the lagoon and of the related ecosystem services. We also provide new insights on the short- and long-term consequences of coastal flooding prevention measures, such as storm-surge barriers, which are being widely adopted globally because of the accelerating rise in sea levels. From this point of view, the Venice and Venice Lagoon issues are becoming the new paradigm of the conflicts arising from the interactions among economy, society, and the environment, the three main pillars of sustainable development, furthermore providing an indication of what fate has in store for coastal cities and ecosystems of the future.