bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismogenic structure of the 2021 Ms6.4 Yangbi earthquake by seismic tomography based on the variation of information 
Authors: Huang Yuqi , Zhang Haijiang , Hu Jing , liu ying , Gao Ji , Moorkamp Max
Published: March 2024

Seismic tomography is a useful tool to obtain the velocity structure of the Earth's interior. Compared with the Vp and Vs models, the Vp/Vs model is of great significance for studying the properties of subsurface structure, such as fluid saturation and porosity.  However, due to different data quality and quantity for P- and S-wave, Vp and Vs models generally have different resolutions and uncertainties, leading to some artifacts in the Vp/Vs model. Tryggvason and Linde (2007) proposed to use the structural similarity in Vp and Vs models to better constrain the Vp/Vs model. However, the clustering relationship between Vp and Vp/Vs models is not optimized, which limits the further geological interpretations based on velocity models. In this study, we aim at developing a new seismic tomography method based on the variation of information for Vp and Vp/Vs models. This method follows joint inversion of magnetotelluric and gravity data based on the variation of information (Moorkamp, 2022), which can improve the clustering relationship between electrical resistivity and density. The 2021 Ms6.4 Yangbi earthquake is located at the intersection of the Red river fault and the nearly north-south trending Lijiang-Dali fault system on the southwestern boundary of the Sichuan-Yunnan block. This earthquake has the classic characteristic of a "foreshock-mainshock-aftershock" sequence. In this study, we have developed a new seismic tomography method based on the variation of information to couple the Vp/Vs model with the Vp model to obtain more reliable Vp, Vs, and Vp/Vs models in the source region of the Yangbi earthquake. Our results show that the foreshocks occur in structures with low Vp, high Vs and low Vp/Vs, while the main shock occurs in the area with high Vp, high Vs and low Vp/Vs. Based on the cross-plot analysis and petrophysical experimental data, we suggest that long-term stress accumulation causes shearing in areas with high quartz content at a depth of 10km. 
Late Paleocene-Early Eocene Climate Warming and Its Influence on Organic Matter Enrichment: Insights from the Kongdian Formation, Bohai Bay Basin, China
Authors: Xin Bixiao , Hao Fang , Sun Weidong , Tian Jinqiang , Xu Qilu , Li Guanlin
Published: March 2024

The late Paleocene to early Eocene was an interval of globally warm climate, during which organic-rich shales were developed in multiple basins. However, the impact of this climate warming on the mechanisms of organic matter enrichment remains unclear, primarily due to a scarcity of precise chronological data and continuous stratigraphic records from terrestrial basins. This study presents a continuous 400 m lacustrine core record from the GD-X borehole spanning the late Paleocene in the Bohai Bay Basin, East China. To reconstruct the palaeoenvironmental conditions and elucidate the mechanisms of organic matter enrichment of Paleocene shales, a series of analyses including total organic carbon (TOC), Rock-Eval pyrolysis, X-ray diffraction (XRD), major and trace elements testing, carbon and oxygen isotopes testing, and Gas Chromatography-Mass Spectrometry (GC-MS) were performed. The results indicate a high abundance of thermally mature Type I and II kerogen in the shales, with most samples exhibiting good to excellent generative potential. The mineralogical compositions are primarily comprised of quartz, feldspar, and dolomite, supplemented by calcite, clay minerals, and analcime. Vertical shifts in paleoenvironmental indicators suggest a climatic transition from semi-humid to arid conditions during the late Paleocene sedimentary period, characterized by reduced input of terrigenous detritus and increased water salinity. These findings indicate that rapid global warming from the late Paleocene to the early Eocene significantly altered precipitation patterns, leading to intensified lake evaporation, diminished surface runoff, and decreased inflow of terrigenous debris into lakes. Consequently, the organic matter enrichment model transitioned from a high productivity-dominated regime to one primarily driven by preservation conditions. Investigating the interplay between environment and biological evolution elucidates the enrichment mechanism of terrestrial organic matter against a backdrop of global climate warming. This research not only provides a scientific basis for predicting the distribution of continental organic-rich shale, but also offers geological insights into the carbon cycle under extreme climatic conditions in Earth's history.
Climate and Media: an efficient and original training for journalists
Authors: Ramstein Gilles , Lansard Bruno , Aballain Olivier
Published: March 2024

During the COP21 which took place in Paris, many climate researchers enhanced their interactions with different population sectors, to explain future and past climate changes.Our group organized a seminar in one of the most prestigious journalist school (ESJ in Lille). Researchers on modelling and documenting past and future climate changes, as well as researchers from human and social sciences, provided a series of seminars. After the session devoted to questions from the audience, journalists and professors of the ESJ came down from the amphitheater. They emphasized the idea that our responsibility as researchers was also to teach journalists the different aspects / impacts of climate change. Their main point was to argue that it was in fact pivotal to get a better understanding of climate issues from the population.This event was the onset of a big project that officially begun in 2016. We took some time to finally build an original training course. The novelty of this formation is based on 3 major ideas: Co-construction of the formation by experts and journalists. For each issue of this training (past and future climate changes, biodiversity, justice, social impacts, economy, energy…), the courses were delivered by two teachers; one scientific expert and one journalist.
The structuration in different themes. Indeed, in most media, there is only one journalist that is responsible for climate and environment. Now that climate changes have modified many aspects of life in general, it is necessary to take them into account.
The accessibility. We decided to train through online-only courses at the level of a Master’s degree. For this first step, we used the large network of ESJ Lille and a collaboration with French-speaking countries to deliver all the lessons in French. This strategy allows students and journalists from more than 20 countries to gain access to this training. For instance, we have students from Haiti, Cameroon, Senegal, Algeria, Ivory Coast, Vietnam, Cambodia, Belgium…
 The present evolution of this training is as followed:Thematic evolution. We are now building new teaching modules that are not based on large issues, but rather on regions which allow us to tackle all the associated impacts. The first one has been finished last year on the Mediterranean basin; and a new one will be developed on the polar region.
Audience evolution. At the beginning, we only had 15 students, most of them being master degree’s students. Now, we have more than 55 students (and more than 150 applications per year), mostly journalists and continuing-education profiles.
The next step, and the main reason for this talk, is to push for similar trainings in different countries. We already have a relationship with South Korea, and would like to provide an English version of our training to share our experience with other scientists and journalists from different countries.
Calibration and verification of high resolution wind speed measurements with quadcopter UAS in a wind tunnel with active grid
Authors: Kistner Johannes , Wildmann Norman
Published: March 2024

The SWUF-3D fleet of unmanned aerial systems (UAS) is utilized for in situmeasurements of turbulence as a contribution to closing observational gaps inthe atmospheric boundary layer (ABL). The wind measurement algorithm usedhas only been calibrated in the free field up to this point. Therefore, we presentthe calibration and verification in a wind tunnel.Calibration is performed in x- and y-coordinate directions of the UAS bodycoordinate frame and in wind speeds of 2 . . . 18 m s−1. We investigate the mea-surement accuracy under different angles of sideslip (AoS) and wind speeds aswell as the portability of the calibration coefficients to other UAS of the fleet.The wind tunnel is equipped with an active grid which is capable of generat-ing measurement scenarios like gusts, velocity steps and statistical turbulence.This allows systematic verification of the measurement capabilities and identifi-cation of limitations. As a reference for the UAS measurements we use constanttemperature anemometers (CTAs).With the derived calibration coefficients the uncertainty depends on the windspeed magnitude and increases with higher wind speeds, resulting in an overallroot-mean-square error (RMSE) of less than 0.2 m s−1. Applying the calibra-tion coefficients from one UAS to others within the fleet results in comparableaccuracies, showing omission of wind tunnel calibration for the remaining UAS.Furthermore, the wind measurement is susceptible to high AoS at high windspeeds. The RMSE for measurements in different gusts is up to 0.6 m s−1. Inthe most extreme velocity steps (i.e. a lower speed of 5 m s−1 and an amplitudeof 10 m s−1) the maximum RMSE occurs and exceeds 1.3 m s−1. For variancesbelow approx. 0.5 m−2 s−2 and 0.3 m−2 s−2, the maximum resolvable frequen-cies of the turbulence are about 2 Hz and 1 Hz, respectively. The verificationin the wind tunnel and the determination of uncertainties helps the analysesof atmospheric measurements in complex terrain and in wind parks where theSWUF-3D fleet is primarily deployed.
Simulation of a satellite gravimetry mission at Mars
Authors: Bredlau Marvin , Bremer Stefanie , Schilling Manuel , Wassermann Noa Katharina
Published: March 2024

Improving the data on the gravitational field of Mars can yield enhanced knowledge about Martian planetary dynamics and subsurface water reservoirs. In this study, we augment the VENQS software tool to perform simulations for a future dedicated satellite gravimetry mission at Mars following the archetype of GRACE-FO and as a result to study the challenges of such a mission.The VENQS software tool consists of two parts: the VENQS App and the VENQS library. The VENQS App provides users with an easy access to a variety of simulation models, that can be combined to an individual VENQS library setup. These simulation models include amongst others orbit propagation of single satellites with embedded test masses, simulations of satellite constellations, and detailed disturbance analysis for satellites due to the space environment. Interaction with versioning systems allows the VENQS App to effectively track the software of the simulation models. In addition, a dedicated release management system enables the provision of different versions of the VENQS library.Initially designed for satellites orbiting Earth, we are working on an augmentation of the VENQS library for interplanetary spacecraft or to be more precise for satellites orbiting arbitrary celestial bodies. In this context we want to propose the adaptation of VENQS for precise orbit propagation at Mars, which can assist the assessment of different mission influences on gravity field recovery (via dedicated software tools such as GRAVFIRE). We present the general simulation procedure including the modelling of perturbating forces along with gravitational acceleration for the orbit integration. Furthermore, we explain the differences to simulations of terrestrial spacecraft and outline occurring challenges with Martian atmosphere, time and reference frames, solid Mars tides as well as more complex satellite geometries inducing micro-vibrations and the non-availability of GNSS, that may deteriorate gravity field solutions.
Study of brightness profiles for different coronal structures
Authors: Lienhart Andrea , Cappello Greta M. , Temmer Manuela , Nistico Guiseppe , Howard Russell , Vourlidas Angelos , Bothmer Volker
Published: March 2024

Extended coronal structures can be observed in white-light using coronagraphs or heliospheric imagers. These instruments observe the Thomson-scattered emission by the electrons of that feature. The scattered emission shows a dependence on the geometry between the Sun, the observer and the scattering structure. The maximum scattering efficiency is obtained on a circle whose diameter is equal to the distance between the Sun and the observer (called Thomson surface). The aim of this study is to investigate the brightness profile of different coronal features in terms of the Thomson-scattering geometry using data from the Wide-Field Imager for Solar Probe (WISPR) aboard Parker Solar Probe (PSP). Due to the special orbit of PSP, the size of the Thomson surface is constantly changing. Brightness curves are calculated for features with different properties, e.g. static structures such as helmet streamers, dynamic but compact structures such as streamer blobs and expanding structures such as coronal mass ejections. The results are then compared with raytracing simulations.
A spectrum of fault slip behaviors induced by fluid injection on a rate-and-state fault depending on time of injection relative to its natural fault cycle
Authors: Pardo Silvio , Tinti Elisa , Van den Ende Martijn , Ampuero Jean-Paul , Collettini Cristiano
Published: March 2024

Fluid induced seismicity represents a significant issue for numerous activities related to geo-energy production. Enhanced geothermal systems, enhanced oil recovery, disposal of wastewater and carbon dioxide capture and storage are associated with subsurface fluid injection that can change the state of stress within the crust and can induce or trigger earthquakes. In several regions, M>3 earthquakes occurred following fluid injection, whereas in others seismicity has been accompanied by slow slip events. Although several mechanisms have been proposed to explain slow slip associated with fluid injection, the conditions leading to the observed spectrum of fault slip behavior still remain elusive. Here we used a quasi-dynamic boundary element method, the QDYN earthquake cycle simulator, to model the response of a fault governed by rate-and-state friction to fluid injection within a reservoir. We imposed low long-term loading rates to simulate a fault located in an area of slow active deformation, leading to natural earthquake cycles with very long recurrence times. We then imposed fluid pressure perturbations (one-way coupling) at different stages of the seismic cycle, to evaluate pore-pressure effects on the triggering of the next event. Our results show that for injection at high fluid pressure, earthquakes are in general immediately triggered (during injection or soon after) irrespective of the stage (early or late) of the seismic cycle, whereas at lower fluid pressure fast triggering is observed only when injecting in the late stages of the seismic cycle. Our models produce a spectrum of fault slip behavior, from regular to slow earthquakes. The latter are observed for specific fluid pressure, flow rate and injection time relative to the seismic cycle. The physics underlying this complex slip behavior remain to be explained, and further studies are required to define the injection conditions that favor the occurrence of slow slip instead of regular earthquakes.
XAI for small-data problems in remote sensing: monitoring Atlantic forests with UAVs
Authors: Chandramouli Pranav , Gevaert Caroline M. , Nattino Francesco , Ku Ou , Aguiar Pedro Alexandra , do Prado Oliveira Patricia , Hortal Pereira Barreto Eduardo , de Ovileira Felipe
Published: March 2024

Despite the increased availability of UAV / drone imagery in Low- to upper  Middle-Income countries and the demonstrated potential of deep learning to support the interpretation of these images for sustainable development purposes, practical operations in these countries are constrained by the need for sufficient labeled data-sets which are often difficult to obtain (especially for tropical forest). This makes it difficult to train suitable networks and assess whether the model is performing well. One such example is the use of drones to monitor the Atlantic Forest in Sao Paulo, Brazil. Here, members of the Sao Paulo Municipal Green and Environment Secretariat (Secretaria do Verde e do Meio Ambiente - SVMA) are starting to use drones to  identify some native and invasive species in their forests. Deep learning will quickly speed up this process, but there is little training data available. This refers to the so called ‘small-data problem’ commonly found in DL for remote sensing applications [1]. A workflow was designed to support this application through a novel zero-shot learning technique and explainable AI methods. A pre-trained tree-crown detection model ‘DeepForest’ [2] is used to identify individual tree crowns in the UAV imagery. The detected tree-crowns are further classified using a Siamese network architecture using zero-shot learning – the model is trained on relevant data-sets but not exposed to species found in the test data-set. A Siamese network architecture is motivated by the need for explainability in DL models – the results will be used for making administrative decision for forest management. A more intricate DL model (such as image segmentation) could be more accurate but at the cost of transparency/explainability. In particular, we apply a variation of the ‘What I Know’ (WIK) explainability method [3] which provides examples from the training set along with the test sample increasing transparency and understanding of the model results.[1] Safonova, Anastasiia, et al. "Ten deep learning techniques to address small data problems with remote sensing." International Journal of Applied Earth Observation and Geoinformation 125 (2023): 103569.[2] Weinstein, Ben G., et al. "DeepForest: A Python package for RGB deep learning tree crown delineation." Methods in Ecology and Evolution 11.12 (2020): 1743-1751.[3] Ishikawa, Shin-nosuke, et al. "Example-based explainable AI and its application for remote sensing image classification." International Journal of Applied Earth Observation and Geoinformation 118 (2023): 103215.  
Increased up-glacier thinning in four major glaciers of High Mountain Asia revealed by geodetic mass balance estimates
Authors: Mandal Arindan , Bhardwaj Anshuman , Azam Mohd Farooq , Vishwakarma Bramha Dutt , Angchuk Thupstan
Published: March 2024

Given its profound implications for future water security, the response of High Mountain Asia (HMA) glaciers to climate change remains a topic of critical concern. While recent studies have primarily focused on small glaciers (with glacierised areas of less than 1 to ~20 km2) to understand the impact of climate change on HMA water resources, these studies assume that smaller glaciers are regionally representative. However, it has been shown that smaller glaciers respond differently due to their smaller accumulation area particularly during warm years and lesser hydrological contribution. On the other hand, large glaciers in a catchment often serve as major contributors to runoff, thus influencing long-term water availability. Hence, larger glaciers may offer a more representative understanding of regional changes and are essential for future water security.In this study, we calculate the geodetic mass balance of four very large glaciers —Fedchenko (with a total area of 664 km2), Baltoro (809 km2), Bara Shigri (112 km2), and Gangotri (122 km2)— covering the period from 2009 to 2022. The analysis is conducted over two different time intervals, utilizing digital elevation models generated from ASTER stereo imagery. We examined distinct glacier surfaces — debris-covered, clean-ice, and accumulation areas — to discern mass loss patterns with elevations. Bias-corrected in-situ meteorological data along with surface ice velocity data (from ITS_LIVE and Sentinel-1) were used to elucidate recent mass balance patterns.Results reveal an amplified mass loss rate during the recent period of ~2015-2022 compared to the preceding period of ~2009-2015. Bara Shigri is an exception, experiencing a slight reduction in mass loss during ~2015-2022. The increased mass loss is driven by rising local summer temperatures and declining winter precipitation. Thinning was prominent at higher elevations (> 5000 m a.s.l.) across all four glaciers, with its intensity increasing over time. This indicates warming in the accumulation areas of these glaciers. Furthermore, upper glacier areas near the equilibrium line altitude exhibited stable ice velocities in certain glaciers, and the lower ablation zones experienced gradual slowdown, likely due to persistent mass loss.These findings highlight the propagation of up-glacier thinning in large HMA glaciers, indicating mass loss across higher elevations and underscoring the vulnerability of local river systems and water resources.
The Central Europe Refined analysis version 2 (CER v2): Dynamical downscaling of ERA5 precipitation data for the metropolitan region Berlin-Brandenburg
Authors: Bart Frederik , Schmidt Benjamin , Wang Xun , Holtmann Achim , Scherer Dieter , Meier Fred , Otto Marco
Published: March 2024

The Central European Refined analysis (CER) was developed in 2016 as a high-resolution, reanalysis-based, gridded dataset for Central Europe. The second version (CER v2) aims to further improve the performance of the CER with a particular focus on precipitation data for the metropolitan region Berlin-Brandenburg. The simulation setup consists of two-way nested, cascaded domains for Germany (10 km grid spacing) and the region Berlin-Brandenburg (2 km grid spacing) and employs a daily re-initialization approach. Major changes from the precursor version include the use of ECMWF-ERA5 reanalysis forcing data and a newer WRF version, allowing for the production of longer time series. To further improve the precipitation performance for the CER v2 we performed sensitivity experiments with five cumulus and five microphysics schemes. The results of these test simulations were evaluated using one year of daily precipitation data at 244 stations of the German Weather Service (DWD) in the 2 km domain of the model.  The best average performance was achieved for a combination of the conventional Kain-Fritsch cumulus and the Thompson microphysics scheme. Using this setup, we simulated the precipitation conditions for 30 years (1991-2020) and evaluated monthly and annual precipitation averages against station and radar data by the DWD. Here, the CER v2 showed a significant reduction in deviations and mean bias compared to the previous version. Based on the spatial resolution of the ERA5 data, we resampled the CER v2 and observational data to compare the performance of both datasets. We observed a wet bias in the ERA5 precipitation data for this region, which was significantly reduced in the CER v2. Results of monthly averages indicated a comparable performance to ERA5 data throughout most of the year. Deviations from the observational data were typically higher during the summer months. However, due to the significant bias reduction and the high spatial resolution, the CER v2 could provide important insights about the local- to mesoscale precipitation dynamic of this region.
Spatial analysis of catastrophic flooding in the metropolitan area of Murcia over the last 100 years
Authors: García Fernández Ester , Albaladejo-Gómez Juan Francisco , Gincheva Andrina , Gil-Guirado Salvador , Pérez-Morales Alfredo
Published: March 2024

Floods represent the most diverse, destructive and frequent natural hazard worldwide and are one of the most significant causes of loss of economic and social assets. In recent years, an increase in the quantity and intensity of this phenomenon can be observed. The factors are manifold, but two stand out: increased hazards as a consequence of anthropogenic climate change and increased exposure and vulnerability of the population and its economic assets. One of the most conflictive areas of the planet are the Mediterranean regions, due to the combination of both factors. Among the hot spots, the Southeast of Spain stands out, with a situation aggravated by a semi-arid climate, but with a highly irregular and torrential rainfall distribution.These factors are particularly problematic in urban areas, making it necessary to precisely locate the areas at risk in order to establish effective adaptation measures. For this reason, this paper compiles historical information on the main flood events from 1900 to the present in the metropolitan area of Murcia, the main urban area in southeast Spain. The information collected comes from newspaper sources. Subsequently, this information has been geolocated and analyzed with Geographic Information Systems. The results reveal that, in general terms, the damage is concentrated mainly in the areas near the Segura River. Additionally, and to a lesser extent, there is a significant concentration in its main tributary, the Guadalentín River. However, it should be noted that during recent flooding episodes, the areas affected are being modified, involving new urbanized areas, far from the main riverbeds and located in flood zones due to the passage of secondary watercourses such as wadis. Finally, it is worth noting that there has been an increase in the number of low-intensity damage points. However, on a positive note, it has been observed that higher intensity damage is decreasing.
Testing the Adequacy of 7533 KGE Calibrated Conceptual Model Structures
Authors: Spieler Diana , Schütze Niels
Published: March 2024

Discussions calling for more rigorous evaluation practices for hydrologic models have recently increased. In addition to the widely used aggregated objective functions, hydrologic signatures are becoming common evaluation metrics for testing the adequacy of hydrologic models for specific application purposes.This work calibrates 7533 conceptual model structures using KGE as an objective function. These structures are evaluated based on their accuracy (KGE performance) and their adequacy. We defined adequacy as showing less than a +/- 50% percentage bias on inter- and intra-annual flow representation as well as on ten selected signatures. These signatures represent five aspects of the hydrological regime (magnitude, frequency, duration, rate of change, and timing). The large number of model structures, calibrated to the streamflow of 12 hydro-climatically differing MOPEX catchments, allows general insight into how well common conceptual model structures can represent observed hydrological behavior evaluated by signatures.Results show that a large number of model structures perform accurately (high KGE performance) but almost none of these may be considered adequate (poor signature performance). In nine catchments not a single model can be considered adequate. In the remaining three catchments, only between 1 (0.1%) and 49 (0.7%) of all tested model structures are adequate according to all testing requirements. While inter-annual mean flow representation is typically represented well, the number of models able to represent intra-annual mean flow and/or individual signatures rapidly decreases.This study presents overwhelming evidence that traditional single-objective function-based calibration is unlikely to return model structures that adequately represent complete hydrologic regimes. We therefore recommend that any model intercomparison or evaluation study needs to be constrained with additional data and/or evaluated by more meaningful metrics than traditional objective functions alone.
Assessing the Ecological Dynamics of Lake Tanganyika: Remote Sensing Insights into Seasonal Hydrodynamics and Human or Climate-Induced Changes
Authors: Toussaint François , Alonso Alice , Vanclooster Marnik
Published: March 2024

Lake Tanganyika, one of the world’s largest freshwater body and located in East Africa, is under threat from both anthropogenic activities and climate change. The region strongly depends on it as a vital resource for water and food for the surrounding populations while pollution is increasing and fish catches and size are decreasing.The characterization of Lake Tanganyika’s hydrodynamics, surface primary productivity and their changes over the past decades has not often benefited from remote sensing observations. In this study, we use satellite-derived estimates of surface chlorophyll-a concentration from ESA’s CCI Lakes dataset to enhance our understanding of Lake Tanganyika's hydrodynamics and more particularly the seasonal spatial patterns. Then, we focus on the analysis of the spatiotemporal changes of this variable over the past two decades with a subsequent effort to discern the underlying factors contributing to these observed changes.After applying the DINEOF method for spatiotemporal interpolation, we comprehensively described the seasonal dynamics in surface chlorophyll-a concentration. We showed that the main patterns are the contrasting dynamics in the coastal and pelagic regions of the lake, explaining nearly 80% of the variance. The observed 20-year trends in primary productivity confirmed the hypothesis that primary productivity is decreasing in the pelagic regions of Lake Tanganyika, as asserted by earlier studies. This phenomenon can be attributed to the impact of climate change on air temperature and wind velocities in the region. These negative trends were found most dominant between March and June, and amount to around -0.5 mg.m-3.decade-1. We also showed a relative sharp increase in primary productivity (+0.5 to 2 mg.m-3.decade-1) in coastal regions near urban centres and river mouths, most notably in the North near Bujumbura and the outlet of the Ruzizi river. This most certainly illustrates the growing impact of the surrounding populations on the lake’s water quality.
Identifying input and output data errors in the calibration of a water quality model using Bayesian error analysis with reordering (BEAR) method
Authors: Wu Xia , Marshall Lucy , Sharma Ashish , Duan Qingyun
Published: March 2024

The presence of errors in water quality and hydrologic variables can significantly impair the calibration of water quality models. To enhance the estimation of model parameters, it is important to accurately identify data errors during the calibration process. However, this task is challenging due to the complex interactions between model parameter uncertainty and data uncertainty. Existing methods for incorporating data uncertainty in model calibration have limitations, such as high-dimensional computation or the inability to handle stochastic errors.To address these challenges, a novel method called Bayesian Error Analysis with Reordering (BEAR) has been developed. Given that the data uncertainty arises from the data itself and is independent of the model calibration or simulation, the cumulative distribution function (CDF) of the data error can be estimated ahead and regarded as the prior information of Bayesian inference. Then the values of data error series only depend on their ranks in the CDF. BEAR method transforms the values of data error series into their ranks in the CDF. This transformation enables the effective identification of input and/or output data errors in water quality calibration.The innovation of the BEAR method can be attributed to several key aspects:1) Modification of the secant method to handle the non-linear transformation from input to output, ensuring the correspondence between the rank of input data error and the residual error of the model.2) Decomposition of model simulations to calculate the delay between each input and its corresponding output.3) Utilization of the Autoregressive model to account for the correlation of residual errors.4) Selection of an appropriate updating logic to minimize the compensation effects among multiple sources of data uncertainty.Overall, the BEAR method demonstrates flexibility and adaptability to various environmental modelling scenarios, making it a valuable tool for improving model specification under conditions of data uncertainty.
EarthCARE Processors and Products: Status Update and Outlook
Authors: Hummel Timon , Bernaerts Dirk , von Bismarck Jonas , Deghaye Patrick , Eisinger Michael , Fehr Thorsten , Frommknecht Björn , Koopman Robert , Rusli Stephanie , Tzallas Vasileios , Wallace Kotska
Published: March 2024

The Earth Cloud Aerosol and Radiation Explorer (EarthCARE) is a satellite mission carried out by the European Space Agency (ESA) in collaboration with the Japan Aerospace Exploration Agency (JAXA) to measure global profiles of aerosol, cloud and precipitation properties along with radiative fluxes and derived warming rates, with the goal of advancing our understanding of cloud-aerosol and radiation interactions and the Earth's radiative budget.In order to fulfil its objectives, the EarthCARE mission will collect co-registered observations from a suite of four instruments located on a common platform. The optical payload encompasses the three ESA instruments, namely an ATmospheric LIDar (ATLID), a Multi-Spectral Imager (MSI) and a BroadBand Radiometer (BBR). The fourth instrument, provided by JAXA, is the Cloud Profiling Radar (CPR). The two active instruments (ATLID and CPR) will provide vertical profiles of the atmosphere along the satellite nadir path. The two passive instruments (BBR and MSI) will provide scene context information to support the active instruments data interpretation.The presentation will provide an update on the status of EarthCARE processors and products prior to launch, focusing on ESA's ground science data processing chain, which includes the production of calibrated instrumental data (Level 1 data products) and retrieved geophysical data (Level 2 data products). Further, we will introduce the Data Innovation and Science Cluster (DISC) for the mission exploitation phase (E2). The DISC brings together several groups of instrument and product experts in one cluster to establish a comprehensive product quality assurance framework, including activities related to product algorithm evolution, data assimilation, calibration, validation support, and performance monitoring of ESA's EarthCARE products.
Contextualizing recent extreme floods in the Western Mediterranean region: insights from historical records and paleoflood hydrology
Authors: Ballesteros-Canovas Juan Antonio , Grodek Tamir , Naharro Carlos , Barriendos Josep , Barriendos Mariano , Medialdea Alicia , Muñoz-Torrero Alberto , Benito Gerardo
Published: March 2024

The Mediterranean region is expected to experience more extreme rainfall events due to climate change. These extreme weather events, together with the ever-increasing human occupation, could lead to an increase in the risk of flash floods. This situation could be worrying, as wildfires may occur during hotter and drier summers, which might increase the hydrological response. Adaptation and mitigation strategies need to be put in place at the level of water and civil protection authorities. However, this is challenging due to the widely recognised lack of data, the high variability of the Mediterranean hydroclimate, and previous shortcomings in the performance of climate-based models for the region. Here, we combine historical, geological and tree-ring data to provide a compressive multi-century reconstruction of flood frequency and magnitude for the Clariano River, a medium-sized (265 km2) Mediterranean catchment in the Province of Alicante (Spain). A historical flood database was collected from published compilations, documentary sources, photographic archives and newspapers. The Municipal Archive at Ontinyent provided flood evidence since CE 1320 with a continuous flood record since 1500. Slackwater flood deposits were studied in ten stratigraphic profiles on three river reaches, and flood units were dated by radiocarbon and optically stimulated luminescence. Finally, thirty-five scarred trees growing on floodplains in three different river reaches were sampled to record the occurrence of recent floods. In three river reaches, 1D and 2D hydraulic models were implemented on high-resolution topographies to convert palaeostages and historical levels into flood discharge. The multi-source data compilation provides evidence of at least 47 major floods since the 13th Century. Apart from the flood caused by the dam break in 1689, the magnitude of the most recent floods caused by mesoscale convective cells in 2016 and 2019 were similar to or slightly below in magnitude to those experienced during the rich flood period (1850-1895) following the end of the Little Ice Age. This implies that the information on past extreme floods could be used as a scenario-based approach to quantify expectations of recent extreme floods under climate change scenarios. Furthermore, our records have allowed a more accurate estimation of flood frequency in Ontinyent city, which could be used to provide a more robust flood hazard zonation. Throughout this comprehensive study, we show that quantitative historical and palaeoflood hydrology allows the determination of past and recent flood magnitude response to climate variability, reducing the uncertainties in flood hazard and risk assessment in the Mediterranean region.
Uncovering the link between river conservation and disaster risk reduction through the invisible connection between people and rivers
Authors: Scaini Anna , Scaini Chiara
Published: March 2024

Risk depends on the frequency and magnitude of river-related hazards, but also on the number, type and economic value of exposed assets (i.e. the exposure). For this reason, land use planning can increase or decrease the overall societal exposure to river-related risks. In this contribution, we bring together experiences that look into understanding and mapping the perception of river-related risks (both from and to the river) as well as riverine socio-cultural values linked to rivers, such as identity and sense of place. These connections between locals and rivers are essential to understand how to mitigate, adapt to, and revert the effects of human-induced changes on rivers. Using a transdisciplinary approach including questionnaires, interviews, a map-based participatory approach as well as evidence-based data on land and water use, biodiversity and risks, we look into how the perception of such values can influence water resources- and decision management in rivers including Tagliamento (Italy), Soča/Isonzo (Slovenia/Italy), and Upper Neretva (Bosnia-Herzegovina). We look into differences and commonalities in light of conflicting values, such as risk management, energy production and land use impacts on water resources and biodiversity, and transboundary water issues. We explore the synergies between river conservation efforts and ecosystem-based land use planning, and discuss the potential benefit of integrating local knowledge and historical evidence in assessing river-related hazards. 
Complex network-based analysis of the spatial evolution of the flash droughts over India
Authors: Pachore Akshay , Remesan Renji
Published: March 2024

Flash droughts, characterized by a rapid decline in soil moisture, are short-term drying events that can cause significant damage to crops when they occur during the growing season. Understanding the spatial and temporal evolution properties of flash droughts is crucial for the effective mitigation and management of this extreme event. The present study employed the complex network theory to assess the spatio-temporal properties of the flash drought which was quantified using the soil moisture percentile drop (SMPD) based definition during the period from 1981 to 2020 over the entire Indian region. An event synchronization (ES)-based complex network is constructed and the spatial propagation of the flash droughts is analyzed using the unidirectional and directed complex networks-based metrics i.e., strength, direction, and distance. Initial results gave insights into how the flash drought hotspots are connected in space and their temporal evolution pattern. From the result of the distance metrics, it was observed that flash drought propagates for longer distances in the central-eastern and southern peninsular regions as compared to the rest of the regions over India. Inference gained from the present analysis can be useful for building an early warning system for flash drought in terms of onset and spatial propagation along with insights on the spatially connected flash drought vulnerable regions.           
Locating mine explosions in shallow waters from hydroacoustic waves using DAS
Authors: Jensen Emil Fønss , Damsgård Jonas F. , Voss Peter H. , Funck Thomas , Hansen Thomas Mejer
Published: March 2024

Of the roughly 50.000 mines that were deployed in Danish waters during the First and Second World Wars, the Royal Danish Navy estimates that 4.000 to 6.000 units remain unexploded. Naval mines are to this day regularly found by fishermen or during surveys related to offshore construction work and reported to the Royal Danish Navy who then undertakes their controlled detonation. Seismic and hydroacoustic signals from naval mine explosions have been recorded by distributed acoustic sensing (DAS) on subsea fiber optic cabling where the hydroacoustic waves are readily identified. We have developed a simple technique that uses inversion of the travel time of hydroacoustic signals to determine the location of explosions. The technique has also been tested on hydroacoustic waves from a marine air gun seismic survey that crosses a fiber cable in shallow water monitored by DAS. We present the inversion results in addition to the data processing and analysis.
Mineral inclusions under non-ambient conditions
Authors: Campomenosi Nicola , Angel Ross John , Alvaro Matteo , Mihailova Boriana
Published: March 2024

Mineral inclusions represent a real treasure in earth sciences because of their large range of applicability to unravel metamorphic and geodynamic processes. For instance, the contrast in the thermal expansion and compressibility coefficients between a mineral inclusion and its surrounding host leads to a residual pressure in the inclusion (Pinc) that, once determined at ambient conditions, can be used to back-calculate the pressure and temperature of entrapment (e.g. Rosenfeld and Chase, 1961; Angel et al. 2015). The Pinc can be quantified via in situ Raman spectroscopy, using ab initio calibrations (e.g. Murri et al. 2018). In addition, Raman spectroscopy can be used to explore the evolution of residual pressure in mineral inclusions under non-ambient conditions. We have analysed quartz-in-garnet (QuiG) host-inclusion systems in situ under high external pressure applied with a diamond-anvil cell at room temperature. The evolution of quartz Pinc calculated from the Raman data collected on fully encapsulated inclusions at high pressure agrees with the predictions calculated from the equations of state and confirm that the garnet host acts as a pressure shield to the softer quartz inclusion. The pressure-dependent sharpening of the A1 mode near 207 cm-1 indicates that quartz inclusions become metastable against coesite at values of Pinc of ~ 2.4 GPa, which corresponds to the pressure of the quartz-coesite phase boundary at room temperature of free crystals (Bose and Ganguly 1995). However, the external applied pressure may exceed the Pinc of more than 2 GPa. Finally, we show that “partially” encapsulated inclusions undergo significant non-hydrostatic stress with evident symmetry-breaking due to heterogeneous host-shielding effects. At room temperature, such deviatoric stresses do not affect the metastability of quartz inclusions with respect to coesite.Financial support by the Alexander von Humboldt Foundation to N. Campomenosi., and by the European Research Council (ERC) grant agreements 714936 to M. AlvaroAngel, R. J., et al. (2015).  Journal of Metamorphic Geology, 33(8), 801-813.Bose, K., & Ganguly, J. (1995). American Mineralogist, 80(3-4), 231-238.Kaminsky, F. (2012). Earth-Science Reviews, 110(1-4), 127-147.Murri, M., et al. (2018). American Mineralogist, 103(11), 1869-1872.Rosenfeld, J. L., & Chase, A. B. (1961). American Journal of Science, 259(7), 519-541.
Major drivers of summer extreme precipitation over the Yangtze River Basin
Authors: Lin Yucong , Gualdi Silvio , Scoccimarro Enrico
Published: March 2024

Utilizing ERA5 reanalysis data, we carried out a series of analyses to investigate the major drivers influencing the interannual variability of summer extreme precipitation over the Yangtze River Basin (YRB) during 1950-2021. We found that both ENSO and IOD have the capability to generate anomalous anticyclones/cyclones over the Western North Pacific (WNPAC/WNPC), which in turn can enhance or diminish water vapor transport, leading to an increase or decrease in summer extreme precipitation over the YRB. However, the impact of negative ENSO-IOD forcings is generally weaker than that of positive forcings. The persistence of the abnormal tropospheric WNPAC/WNPC is primarily driven by local thermodynamic forcing and feedback from the Indian Ocean Basin Warming (IOBW). It is noteworthy that only strong ENSO events can trigger the anomalous IOBW, resulting in more pronounced responses in summer extremes. Notably, the negative ENSO-IOD phases yield non-linear outcomes, thus offering less robustness for the predictability of summer extremes over the YRB. This study provides valuable insights into the interannual variability of summer extreme precipitation in the YRB, highlighting the key predictors and physical mechanisms responsible for these variations.
Keywords: Yangtze River Basin; summer extreme precipitation; ENSO; IOD; Indian Ocean Basin Warming; WNPAC
Moho Depth Model and Structural Characteristics of China and Adjacent Regions
Authors: Xue Zhixin , Guo Dongmei , Fang Jian , He Huiyou
Published: March 2024

The Moho interface is an important parameter for describing the structure and morphology of the Earth's crust, and it is of significant importance in the study of the formation and evolution of the crust and mantle, as well as deep-seated dynamic processes (Stern et al., 2018). Existing Moho models derived from seismic data often suffer from inaccuracies due to irregular distribution and regional imbalances of seismic data. However, with the development of gravity satellite technology, high-precision satellite gravity data has injected new vitality into the study of lithospheric tectonic features and crustal evolution. In this study, constrained by seismic data (Li et al., 2013; Zhang et al., 2021), we utilized an improved regularized Bott method (Uieda et al., 2017) to invert high-precision satellite gravity data and obtained a high-precision unified Moho depth model for the East Asian region, encompassing both land and sea areas. The research results show that the Moho depth model exhibits a continuous increase in depth from east to west, and its overall distribution in the horizontal direction is non-uniform, displaying distinct regional block features. This paper provides a high-resolution and high-precision Moho model for studying the evolution of the East Asian continental tectonics and plate interactions, and further discusses the macrostructural framework and geological implications of East Asia.ReferencesLi Y Gao M, Wu Q. Crustal Thickness Map of the Chinese Mainland from Teleseismic Receiver Functions [J]. Tectonophysics, 2013, 611.Stern, Robert, J, et al. Continental crust of China: A brief guide for the perplexed [J]. Earth Science Reviews the International Geological Journal Bridging the Gap Between Research Articles & Textbooks, 2018.Uieda L, Barbosa V. Fast nonlinear gravity inversion in spherical coordinates with application to the South American Moho [J]. Geophysical Journal International, 2016.Zhang J , Yang G , Tan H , et al. Mapping the Moho depth and ocean-continent transition in the South China Sea using gravity inversion [J]. Journal of Asian Earth Sciences, 2021, 218(3–4):104864.