bluuebunny/crossref_metadata_2025 huggingface dataset:
Ground Penetrating Radar of a beach ridge system on Phra Thong Island, Thailand reveals repeat Late-Holocene tsunami events on a background of falling sea level
Authors: Switzer Adam , Kumar Rahul , Gouramanis Chris , Bristow Charles , Shaw Timothy , Kruawun Jankaew , Brill Dominik
Published: March 2024

This study examines ground penetrating radar (GPR) records of beach ridge stratigraphy as a proxy for reconstructing regional sea-level and tsunami histories in the tropics. We present topographically corrected GPR profiles on a prograded coast in Phra Thong Island, Thailand where we 1) identify downlap points marking the boundary between foreshore / beachface and upper shoreface facies and use this as past sea-level marker and 2) identify ‘cut and fill’ packages in the upper fill that we infer to be records of past erosion and recovery following repeated tsunami events. Optically Stimulated Luminescence (OSL) dates collected at locations slightly offset from the same profile line were incorporated to create the temporal record. The shore-normal GPR record shows ~0.82 m fall in the sea-level between 2659±139 years BP to 367±27 years BP that is consistent with other proxy based sea-level curves obtained in the region. The early part of the record (before ~2600 years) presents a period of rapid progradation and relatively stable sea level conditions. From ~2600 years BP to ~2200 years BP the record shows a steeper fall in sea level followed by a relatively stable to slightly falling phase between ~2200 years BP and ~550 years BP. Finally, for the seaward side, between ~550 years BP and ~350 years BP, the record indicates falling relative sea-level. The cut and fill packages suggest that Phra Thong has experienced 5 tsunami events in the last 2600 years including two events in close succession around 500 years ago that are recorded in the most landward part of the sequence.  This study confirms that the study of tropical beach ridge systems using GPR and OSL techniques can be highly effective for reconstructing regional sea-level trends and tsunami histories through the Common Era and beyond.
Application of topological filtering (DPS) algorithm for identifying linear seismogenic structures in the Lake Baikal region
Authors: Agaian Anastasiia , Nekrasova Anastasia , Bogoutdinov Shamil
Published: March 2024

The Topological Filtering Algorithm, Discrete Perfect Set (DPS) by Agayan et al. (2018), was developed within the framework of discrete mathematical analysis, which involves fuzzy models of discrete analogs of fundamental concepts of classical mathematical analysis. It is designed to select clusters of discrete observations according to a given criterion (classification of discrete observations belonging to one of the clusters) (Gordon, 1981). In this study, we applied the iterative S-DPS modification of the DPS algorithm (Agayan et al., 2022) for the sequential extraction of linear structures from an initial array of point objects. Specifically, we considered the catalogue data from the Baikal Division of the Geophysical Survey, Federal Research Center of the Russian Academy of Sciences, as the initial set of point objects. In each iteration, the densifications identified by S-DPS can be interpreted as discontinuous disturbances of various ranks. With each iteration, weaker yet significant concentrations are discerned. The identification of these discontinuous disturbances as linear structures, and their interpretation were conducted using an expert, non-automated approach.Derived from expert analysis of a few sequential iterations of the S-DPS algorithm, this facilitated the identification of potential seismogenic structures for two selected territories in the Lake Baikal region. For both territories, the obtained structures were compared with the mapped active faults in the Lake Baikal region (Active Faults of Eurasia Database, Zelenin et al., 2022).The iterative application of the S-DPS algorithm, combined with expert linear structures analysis, provides a nuanced approach to understanding the complexities of seismogenic features and their potential seismic implications. This methodology offers significant potential for analysing regional seismicity, aiming to discover new or adjust already mapped seismogenic structures.ReferencesAgayan SM, Bogoutdinov SR, Dzeboev, BA, Dzeranov BV, Kamaev DA, Osipov MO DPS Clustering: New Results. Appl. Sci. 2022, 12, 9335. https://doi.org/10.3390/app12189335Zelenin E, Bachmanov D, Garipova S, Trifonov V, and Kozhurin A: The Active Faults of Eurasia Database (AFEAD): the ontology and design behind the continental-scale dataset, Earth Syst. Sci. Data, 2022, 14, 4489–4503, https://doi.org/10.5194/essd-14-4489-2022.
Enhancing Flood Resilience through Integrated Models in a Streamflow-Scarce Watershed
Authors: Jung Yong , Shin Mun Ju , Jeon Seong Jae
Published: March 2024

A watershed with insufficient streamflow data faces challenges in mitigating flood damages through infrastructure. Many small/middle-size watersheds adopt data from nearby watersheds with sufficient measurements, based on the similarity of watershed characteristics and weather conditions. However, not many areas have optimal conditions to utilize data from nearby sources. To generate streamflow, we employ a regional weather model (the Weather Research and Forecasting model or WRF) and a rainfall-runoff model known as Génie Rural à 4 paramètres Horaires (GR4H). The WRF model generated rainfall data for past years base on the globally simulated data (Final (FNL) data from NCEP) with possible physical atmospheric conditions. The optimally conditioned GR4H produced streamflow data using rainfall data from WRF. All produced streamflow data is statistically tested for the applicability as basic data for background information to decrease the flood damages.
The Related Researches of the Vortex Sourceof Southwest China Vortex Weather System
Authors: li yueqing
Published: March 2024

The Southwest China vortex (SWCV) is that under the special terrain and circulation conditions of the Tibetan Plateau (TP), a meso-α-scale cyclonic low system with 300-500km horizontal scale at 700hPa or 850hPa in Southwest China. Being the important influencing system for the large area heavy precipitation in China summer half year, it is the second rainstorm weather system in China after typhoon in the intensity, frequency, and range of the caused rainstorms. So, SWCV and its weather influences are one of the main directions in Plateau Weather Science. And the research on the vortex source of SWCV has been always the key point of close attention.The new related progresses in researches of the vortex source of SWCV system are reviewed for the last 10 years. In particular，it is recognized that because of the multi-scale effects between the topography and circulation，the vortex source of SWCV has the multi-scale characteristic of its distribution, and there are obviously differences between the structure、evolution、cause and influence of SWCV with the different vortex sources. The vortex sources of SWCV have closely connection each other. The upper-reach vortex sources such as Jiulong&Xiaojin have an important effect on the lower-reach vortex sources such as the Basin. The“effect of upper-reach vortex source”of SWCV, atmospheric gravity wave connecting with the complex topography，internal atmospheric process induced by precipitation, and the anomalous influences of East Asia monsoon are also the formation mechanisms for the vortex source of SWCV. And the formation of SWCV is mainly determined by the speed of incoming airflow in the direction of the main axis of the Hengduan Mountains. The formation vortex source of SWCV is mainly determined by the relative position of the incoming airflow in the windward area and the main axis of the Hengduan Mountains.But, for research on the vortex source of SWCV, there are some problems such as being weaker in fine observation and basic data，being unknown for the multi-scale structures of the vortex source and its evolution, being not deep to understand the formation cause of different vortex sources and being incomplete in study of the SWCV evolutions and its effects of different vortex sources.
A new method for measuring ambient 1,3-butadiene through active DOAS
Authors: Gu Chuanqi , Bin Zhou , Wang Shanshan
Published: March 2024

As one of highly reactive dialkenes, 1,3-butadiene (BD) plays a significant role in the atmospheric radical cycle. We have introduced a novel method for the online measurement of ambient BD using the Differential Optical Absorption Spectroscopy (DOAS) technique. During lab testing, the correlation coefficient (R2) between measured BD concentrations and standard concentrations consistently exceeded 0.9999. The accuracy and precision were within ± 5% and 1%, respectively. Interference testing demonstrated that DOAS can effectively distinguish between substances and accurately fit BD concentrations. Following field measurement, the detection limit for BD reached 90 pptv, the R2 between DOAS and the online VOCs system results reaches 0.85, with a slope of 0.86. With its minute-level temporal resolution and cost-effectiveness, DOAS is suitable for long-term BD measurements and has been further validated as an effective method to provide valuable data support for in-depth investigations into the atmospheric oxidation processes of BD.This work was supported by Sino-German Mobility Program (M-0509) and National Natural Science Foundation of China (grant number 42075097, 22176037, 42375089, 22376030).
Responses of production and concentrations of marine biogenic sulfur to atmospheric dust deposition in the Northwest Pacific
Authors: Xu Feng , Zhang Hong-Hai , Yang Gui-Peng
Published: March 2024

Biogenic dimethylated sulfur compounds such as dimethylsulfide (DMS), methanethiol (MeSH), and dimethylsulfoniopropionate (DMSP) are ubiquitous in marine environments, playing pivotal roles in the global sulfur cycle and climate regulation. Atmospheric dust deposition exerts a significant impact on the Northwest Pacific ecosystem. However, its impact on these compounds in the upper ocean remains inadequately understood. This research examines the effects of atmospheric dust deposition, along with the subsequent influx of nutrients and Fe ions on the phytoplankton community and biogenic sulfur cycle in the Northwest Pacific, utilizing a ship-based incubation experiment. Our findings reveal that nutrient influx, stemming from both dust deposition and nutrient addition, has spurred phytoplankton growth, in which dust deposition also altered the structure of the algae community. These changes have consequently increased DMSP production per phytoplankton cell, leading to higher DMSP concentrations. The abundant nutrient has further amplified the DMSP cleavage pathway, a source of DMS, resulting in elevated DMS levels. Interestingly, the increase in DMSP has offset the reduced DMSP demethylation pathway, a source of MeSH, thus raising MeSH concentrations. While Fe ion addition did not directly boost phytoplankton biomass, it induced environmental oxidative stress, which in turn promoted cellular DMSP synthesis, enhancing both DMSP and subsequently DMS and MeSH production. Nevertheless, the swift oxidation of MeSH by active Fe ions led to a reduction in its concentration. This study elucidates the responses of phytoplankton and biogenic dimethylated sulfur compounds to atmospheric dust deposition, along with the subsequent influx of nutrients and Fe ions. These insights are crucial for accurately modeling the implications of such environmental changes on future climate dynamics.
Quantifying the role of the eddy transfer coefficient in simulating the response of the Southern Ocean Meridional Overturning Circulation to enhanced westerlies in a coarse-resolution model
Authors: Li Yiwen , Liu Hailong , Lin Pengfei , Chassignet Eric , Yu Zipeng , Wu Fanghua
Published: March 2024

The ability of a coarse-resolution ocean model to simulate the response of the Southern Ocean Meridional Overturning Circulation (MOC) to enhanced westerlies is evaluated as a function of the eddy transfer coefficient (κ), which is commonly used to parameterize the bolus velocities induced by unresolved eddies. The strongest eddy-induced MOC response, accounting for 82% of the reference eddy-resolving simulation, is achieved using a stratification-dependent κ with spatiotemporal variability. By decomposing the eddy-induced velocity into its vertical variation (VV) and spatial structure (SS) components, we find that the intensified eddy compensation response is primarily driven by the enhanced SS term, while the introduced VV term weakens the response. Additionally, the temporal variation of the stratification-dependent κ plays a key role in strengthening the eddy compensation response to intensified westerlies. The stronger eddy compensation response in the experiment with stratification-dependent κ than the constant κ can be attributed to the structure of κ and the vertical variation of the density slope. These findings highlight the significance of accurately representing κ for capturing the response of the Southern Ocean MOC and emphasize the role of the isopycnal slope in modulating the eddy compensation mechanism.
Aqueous-phase brown carbon formation from α-dicarbonyls with amines and ammonium: kinetics, chromophores and formation mechanisms
Authors: Huang Ru-Jin , Yang Lu , Yuan Wei
Published: March 2024

Brown carbon (BrC) aerosols play an important role in affecting radiative forcing and atmospheric photochemistry. Laboratory simulation studies show that aqueous-phase reactions of water-soluble carbonyls with ammonium or amines are one efficient BrC formation pathway. However, the identities of most chromophores, the mechanisms affecting the BrC formation kinetics and the role of pH in these reactions remain largely unknown. In this study, we investigated the BrC formation kinetics, chemical structures and formation pathways of previously unidentified chromophores. The results reveal pH-parameterized BrC production rate constants, kII BrC(m-1 [M]-2 s-1), based on the light absorption between 300 and 500 nm: log10(kII BrC) = (1.0 ± 0.1)×pH－(7.4 ± 1.0) for reactions with glyoxal and log10(kII BrC) = (1.0 ± 0.1)×pH－(6.3 ± 0.9) for reactions with methylglyoxal. The chromophores are mainly composed of nitrogen heterocycle compounds initiated by nitrogen nucleophilic addition reaction. Specifically, 155 newly identified chromophores, including 76 imidazoles, 57 pyrroles, 10 pyrazines, 9 pyridines, and 3 imidazole-pyrroles, explain additionally 9-69% of the light absorption, and these chromophores mainly involve four formation pathways, including previously unrecognized reactions of ammonia or methylamine with the methylglyoxal dimer for the formation of pyrroles. The pH in these reactions also shows remarkable effects on the formation and transformation of BrC chromophores. These results will improve our understanding of BrC chemistry, the links with optical properties, and model parametrization of secondary BrC for simulating climate effects of BrC.
Evaluation of Seasonal Changes in the Eutrophication Index and a Eutrophication Alleviation Technique in Osongji (Osong Pond), Jeonju-si, Korea
Authors: Noh Suyeong , Kang Jiyoung , Jeen Sung-Wook
Published: March 2024

Excessive inflow of nitrate and phosphate is a major cause of eutrophication in surface water systems. Eutrophication induces the excessive growth of photosynthetic organisms, leading to the occurrence of algae blooms. Therefore, treating excessive nutrients can be an essential method to alleviate eutrophication. This study aimed to assess the seasonal changes in the eutrophication status in a lake and to evaluate the potential of using Ca-citrate complex for the simultaneous treatment of nitrate and phosphate in the lake environment. Osongji (Osong Pond), a small lake located in Jeonju-si, Korea, was selected as the study site, and the changes in physicochemical parameters and the Korean Eutrophication Index (TSIKO) were used to evaluate the changes in the eutrophication status in the lake. In addition, a eutrophication alleviation technique using ca-citrate complex, was tested under three experimental conditions. The experiments included the application of Ca-citrate complex reagent every two weeks (T1; prevention) or one-time application (T2; one-time application). Closed (T3) and open (T4) controls (without application of the Ca-citrate complex) were also included for comparison. Analysis of seasonal changes in the eutrophication status was conducted every two months from November 2022 to September 2023, and the Ca-citrate complex experiments were conducted from June to September 2023. The results showed that Osongji had the eutrophic condition from November 2022 and the hypereutrophic condition from June to July 2023, and it returned to the eutrophic condition in August 2023. The evaluation of the eutrophication alleviation technique using ca-citrate complex indicated that, in T1 with periodic application, lower TSIKO values maintained compared to the control groups without Ca-citrate complex. In the T2 condition with a one-time application, total phosphorous (T-P) and total nitrogen (T-N) decreased two weeks after application, and TSIKO also decreased. In conclusion, the application of Ca-citrate complex reagent in the lake environment had effectiveness in preventing and alleviating eutrophication. This study can contribute to assessing the degree of eutrophication in a surface water system and developing management strategies for prevention or alleviation of eutrophication.
Synoptic-dynamical view of droughts in the southern Murray-Darling Basin of Australia
Authors: Jin Chenhui , Reeder Michael , Gallant Ailie , Parker Tess , Sprenger Michael
Published: March 2024

Australia is a country prone to drought and has experienced several severe droughts in its recent history. Most studies have linked large-scale modes of variability to Australian droughts, whereas few studies investigate droughts from the perspective of weather systems. In the current study, a wide range of weather systems (cyclones, anticyclones, fronts, warm conveyor belts, potential vorticity streamers, and cut-off lows) are investigated in association with heavy rainfall days that are important to meteorological drought in the southern Murray-Darling Basin. Two distinct phases (development and recovery) of drought are identified based on the standardised precipitation index.This study shows that heavy rainfall days produce less rain during the development phase of drought in the southern Murray-Darling Basin, compared to the recovery phase. The rainfall reduction in the development phases is mainly due to a reduction in the frequency and intensity of rainfall associated with warm conveyor belts. On heavy rainfall days, warm conveyor belts are less frequent and weaker in their strength in the vicinity of the southern Murray-Darling Basin during drought development, whereas they are more frequent, intense, and persistent over this region during recovery from drought. Moreover, the spatiotemporal evolution of rainfall is consistent with the ascending branch of warm conveyor belts, supporting the importance of warm conveyor belts to rainfall.Regarding the source of moisture on heavy rainfall, there is a notable decrease in moisture transport over the Coral Sea during the development of drought, whereas strong moisture divergence is identified in this region during the recovery phase.
Assessment of SMOS soil moisture considering the heterogeneity of geophysical parameters within the footprint
Authors: Gibon François , Mialon Arnaud , Richaume Philippe , Rodriguez-Fernandez Nemesio , Kerr Yann , Aberer Daniel , Bader Nicolas , Boresch Alexander , Crapolicchio Raffaele , Dorigo Wouter , Gruber Alexander , Himmelbauer Irene , Preimesberger Wolfgang , Tercjak Monika
Published: March 2024

Evaluating the uncertainties of satellite soil moisture (as SMOS or SMAP) is crucial for enhancing our comprehension of climate mechanisms, such as the water cycle or the energy balance. The commonly used method is to evaluate the agreement between the satellite data and a reference, which are often ground measurements. However, the measurand in the present case is soil moisture at the satellite footprint scale, which means a much larger spatial and temporal scale than the in situ one. Various methods are employed to address these scale mismatches, such as multiple spatial sampling with in situ measurements within the satellite footprint (dense networks with strategic location installation) or the probes’ classification with representativeness indicators (based on triple collocation analysis, for example). Within ESA's Fiducial Reference Measurement for Soil Moisture project (FRM4SM), we propose to investigate the level of heterogeneity within the SMOS satellite footprint due to its influence on the complexity of the retrieval model and also its influence on the scale mismatch with the reference. To do so, various indices are developed to i) quantify the footprint heterogeneity in terms of the spatial distribution of hydro-geophysical parameters, and ii) analyse the impact on the retrieval quality. We present the analysis using indices of diversity of surface conditions (Shannon and Gini indices), and indices based on the level of similarities of hydro-geophysical conditions between the probes’ environment and the satellite footprint. Results show that even though the Shannon index is not significantly related to the soil moisture retrieval performances, the index based on the similarities of surface conditions better correlates with the retrieval performances.
Ophicarbonates transport carbon to the deep mantle: a case study from the Zermatt-Saas ophiolite
Authors: Piccoli Francesca , Hutter Aaron , Hermann Jörg
Published: March 2024

A large body of work has challenged the paradigm of carbonate stability at the forearc and subarc (> 80 km) conditions in subducted slabs and revealed a variety of complex processes that play an important role in the so-called slow C cycle. Serpentinite-hosted carbonate rocks (i.e., ophicarbonates) are an important rock type for the deep C cycle because they can occur either in the slab or in the mantle wedge. The question revolves around phase stability and metamorphic reactions upon subduction that can lead to a change in carbonate phase assemblage and fluid composition. Moreover, the phase relation between carbonates, silicates, oxide and sulfide minerals in ophicarbonates can be informative about the redox conditions during prograde metamorphism.We present a case study of ophicarbonate rocks from the Zermatt-Saas unit, Western Alps, that were subducted up to eclogite facies conditions at 2.5 GPa, 560° C. In the study area, ophicarbonates overlie a large body of partially dehydrated serpentinites. This allows us to understand whether fluids released from the serpentinites infiltrated the ophicarbonates or not, and to what extent decarbonation reactions occurred in an open or closed system. We investigated three carbonate-bearing rock types: ophicarbonates, olivine-carbonate veins, and a talc-magnesite reaction rind at the contact between ultramafic and mafic/felsic lithologies. Our petrological and geochemical investigation, as well as thermodynamic modelling, reveal that the metamorphic evolution of the ophicarbonate was in a closed system, where calcite/aragonite was replaced by metamorphic dolomite and diopside, and that this reaction is nearly CO2 conservative, with the released fluid composition close to pure water. In situ LA-ICP-MS trace element analyses also show that carbonate in olivine-carbonate veins was most likely sourced from the ophicarbonates. Our thermodynamic modelling indicates that the talc-magnesite reaction zone was most likely formed during early exhumation between 9-13 kbar and 530-460° C, at XCO2 between 0.007 and 0.009. Lastly, we will discuss how the silicate-oxide-sulfide redox buffering assemblage indicates that all three rock types were equilibrated at redox conditions < FMQ.In conclusion, our study demonstrates that in the absence of external fluid infiltration, carbonates in ultramafic lithologies are stable at subduction conditions. This suggests that ophicarbonate have a potential important role in the deep, long term, carbon cycle.
Causal inference of the CO2 fertilisation effect from ecosystem flux measurements
Authors: Biegel Samantha , Schindler Konrad , Stocker Benjamin
Published: March 2024

Land ecosystems play an important role in the carbon cycle, and hence the climate system. The engine of this cycle is Gross Primary Production (GPP), the assimilation of CO2 via photosynthesis at the ecosystem scale. Photosynthesis is directly affected by rising CO2 levels which, in turn, is expected to increase GPP and alter the dynamics of the carbon cycle. However, there is substantial uncertainty about the magnitude and geographical variability of the CO2 fertilisation effect (CFE) on GPP.We use a large collection of eddy covariance measurements (317 sites, 2226 site-years), paired with remotely sensed information of vegetation greenness to estimate the effect of rising CO2 levels on GPP. We propose a hybrid modelling architecture, combining a physically-grounded process model based on eco-evolutionary optimality theory and a deep learning model. The intuition is that the process model represents the current understanding of the CFE, whereas the deep learning model does not implement explicit physical relations but has a higher capacity to learn effects of large and fast variations in the light, temperature, and moisture environment. The hybrid model is set up to learn a correction on the theoretically expected CFE. This makes it more effective in distilling the relatively small and gradual CFE. Our study investigates inherent limitations of different models when it comes to drawing conclusions about the CO2 fertilisation effect. Often, these limitations are due to the presence of latent confounders that give rise to spurious correlations. A promising avenue to address them is therefore the use of causal inference techniques. We show that one way to investigate causality is to test whether the trained hybrid model and its estimate of the CFE is stable across different ecosystems, as expected for a causal physical relation. In summary, we study how causal inference, based on a combination of physics-informed and statistical modelling, can contribute to more reliable estimates of the CO2 fertilisation effect, derived from ecosystem flux measurements.
Event-based features: An improved feature extraction approach to enrich machine learning based labquake forecasting
Authors: Karimpouli Sadegh , Kwiatek Grzegorz , Martínez-Garzón Patricia , Dresen Georg , Bohnhoff Marco
Published: March 2024

Earthquake forecasting is a highly complex and challenging task in seismology ultimately aiming to save human lives and infrastructures. In recent years, Machine Learning (ML) methods have demonstrated progressive achievements in earthquake processing and even labquake forecasting. Developing a more general and accurate ML model for more complex and/or limited datasets is obtained by refining the ‘ML models’ and/or enriching the ‘input data’. In this study, we present an event-based approach to enrich the input data by extracting spatio-temporal seismo-mechanical features that are dependent on the origin time and location of each event. Accordingly, we define and analyze a variety of features such as: (a) immediate features, defined as the features which benefit from very short characteristics of the considered event in time and space, (b) time-space features, based on the subsets of acoustic emission (AE) catalog constrained by time and space distance from the considered event, and (c) family features, extracted from topological characteristics of the clustered (family) events extracted from clustering analysis in different time windows. We use AE catalogs recorded by tri-axial stick-slip experiments on rough fault samples to compute event-based features. Then, a random forest classifier is applied to forecast the occurrence of a large magnitude event (MAE>3.5) in the next time window. Results show that to obtain a more accurate forecasting model, one needs to separate background and clustered activities. Based on our results, the classification accuracy when the entire catalog data is used reaches 73.2%, however, it shows a remarkable improvement for separated background and clustered populations with an accuracy of 82.1% and 89.0%, respectively. Feature importance analysis reveals that not only AE-rate, seismic energy and b-value are important, but also family features developed from a topological tree decomposition play a crucial role for labquake forecasting.
Coupling stormwater protection and aquifer recharge
Authors: Baumann Thomas , Augustin Lea
Published: March 2024

Stormwater in small catchments is a threat to agricultural land use and civilization. Increasing ambient temperatures increase the risks for severe rainfall and surface runoff and reduce the amount of groundwater recharge. At the same time, the demand for irrigation water is rising. This development calls for integrated strategies for stormwater protection and aquifer recharge.In this contribution, we present a case study for a technical solution to infiltrate stormwater into the local aquifer. The site is located in an area well known for hop cultivation. The aquifers are located in tertiary sediments, which are covered with loess and are sometimes semi-confined. Hydraulic conductivities are in the 10-4 m/s range, and specific storage coefficients are between 10-6 (confined) and 0.2 (unconfined). Current stormwater protection plans include retention basins with a capacity of 5500 m³, not all of them fully functional, and flooding events were recorded two times per year. Demand for irrigation was 64 mm for the past five years, with peaks of 118 mm in 2022. Even if only the extreme rainfall events would be recharged into the aquifer, an area of 5-10 ha could be irrigated from the infiltrated water, assuming one extreme event. This is a significant amount of the area (15%) used for hop cultivation around the storage site.Specific challenges at this site are the flood dynamics, the uncontrolled surface runoff, which brings a lot of fines, and the water quality with regard to fertilizers and pesticides. This requires small settling ponds or intermediate storage facilities and adsorbers. Most of the used products, however, have a medium to strong tendency to adsorb on organic carbon and even inorganic materials. The hydrogeological model indicates that the flood water can be infiltrated at high volumetric flow rates without risking upwelling groundwater tables. A detailed site investigation will be completed by mid-2024.
Joint Effects of Winds and Tides on Near-Inertial Internal Waves in the Northern South China Sea: A Three-Dimensional Numerical Study
Authors: Gong Yankun
Published: March 2024

Joint effects of winds and tides on near-inertial internal waves (NIWs) are numerically investigated via a series of three-dimensional quasi-realistic simulations in the northern South China Sea (NSCS). Model results demonstrate that in the presence of wind-induced NIWs, more tidal energy is transferred to NIWs, while in the presence of tide-induced NIWs, the extreme wind (cyclone) would inject less near-inertial kinetic energy (NIKE). The interaction between wind-induced and tide-induced NIWs produces total NIKE more (or less) than a linear superposition of that generated by wind and tide forcing alone at different sites in the NSCS. Specifically, near the Luzon Strait, both tides and winds make positive contributions to the local near-inertial energy input, resulting in more than 30% enhancement of total NIKE (>0.5 kJ m-2). However, in some deep-water regions along the cyclone paths, energy is transferred from cyclones to NIWs and also from NIWs to internal tides. Due to this “energy pipeline” effect, tide- and wind-induced NIWs contribute to weakening of total NIKE (~0.3 kJ m-2 or 30%). Additionally, sensitivity experiments with varying initial tidal phases indicate that the interaction between wind-induced NIKE and tide-induced NIKE is robust in most model domain (over 80%) under different phase alignments between wind- and tide-induced NIWs. From the perspective of cyclones, tide-induced NIKE is comparable to wind-induced NIKE in the Luzon Strait before the arrival of cyclones, while tide-induced NIKE is two orders of magnitude smaller than wind-induced NIKE in most of the NSCS after the arrival of cyclones. Overall, our results highlight the joint effects of wind and tide forcing on the local NIW dynamics in the NSCS.
System Dynamics Modeling for Resilient Water Resource Management in Arid Regions
Authors: Elomri Adel , Aloui Sarra , Zghibi Adel , Mazzoni Annamaria
Published: March 2024

Arid regions confront significant challenges due to the scarcity of natural water resources, leading to the depletion of non-renewable reserves and an escalating reliance on unconventional water sources. The intricacies of water resource management within such regions are compounded by the dynamic interplay of influential factors, including rapid urbanization and population expansion.This research employs an innovative System Dynamics (SD) methodology to construct a comprehensive model aimed at understanding the complex dynamics inherent in water resource management within Qatar, characterized by an arid climate. A Decision Support System (DSS), functioning as a simulated environment, was developed to project the behavioral patterns of Qatar's water resource system from 2021 to 2070. This projection encompasses nine distinct scenarios, categorically addressing changes in physical, environmental, and socio-economic dynamics. These scenarios were further evaluated against Water Sustainability and Reliability Indexes to provide a comprehensive assessment. The outcomes of this study underscore that the conventional “business-as-usual” approach to water resource management can ensure a sustainable balance between water supply and demand for a limited span of 32 years, with the most optimistic scenario extending this sustainability horizon to 50 years. Furthermore, groundwater conservation strategies were integrated and simulated, accentuating the imperative to preserve groundwater resources as an indispensable "backstop" for the nation.The developed model not only addresses Qatar's specific challenges but also offers insights applicable to other Gulf Cooperation Council (GCC) countries and similar arid regions. This research contributes a robust decision-making tool for policymakers and stakeholders to assess the long-term implications of various management scenarios. It contributes to the development of sustainable and resilient water policies for the years to come, particularly in navigating the uncertainties inherent in arid region water resource management.
Dynamic study of extreme climate events based on the three-pattern decomposition of global atmospheric circulation
Authors: Peng Jianjun , Hu Shujuan
Published: March 2024

In recent years, the eastern China and even the whole northern hemisphere have suffered from frequent extreme climate events in summer. For example, the extremely hot summer of 2018 over East Asia, the abnormal precipitation in eastern China in the midsummer of 2021, and the high summer temperature in the Northern hemisphere in 2022 August. These extreme climate events have brought severe challenges to human life, economic development and ecological environment. Revealing the physical mechanism of such events is of great significance for disaster prevention and mitigation and policy making.In fact, atmospheric circulation anomalies play an important role in regulating extreme climate events on a regional scale. However, the existing research mainly focus on the influence of the horizontal vortex circulations processes such as blocking and wave train, but the effects of local vertical circulations, especially the interaction between the local vertical and horizontal circulations, are still lacking. To explore a dynamic approach that considers the actual atmospheric circulation as a whole, Hu et al. (2017,2018a, 2018b, 2020) proposed a novel method called the three-pattern decomposition of global atmospheric circulation (3P-DGAC). Unlike the traditional two-dimensional decomposition method, which ignores the effects of the horizontal motion of low-latitudes and the vertical motion of mid-high latitudes, this method considers the effects of mid-high latitude divergent circulation and low latitude vortex circulation on the actual atmospheric circulation, which is conducive to the study of the dynamics of the actual atmospheric circulation from the global perspective. Specifically, the 3P-DGAC extends Rossby wave at mid-latitudes, Hadley circulation and Walker circulation at low latitudes to the global scale, and argues that the actual atmospheric circulation can be understood as the sum of the superposition of the horizontal vortex circulation, the meridional and zonal circulation. Thus, the 3P-DGAC provides a suitable tool for studying the dynamics of three-dimensional structure of local atmospheric circulation.Using the 3P-DGAC method, we have studied the dynamics of the extreme climate events that have occurred in recent years and revealed the corresponding physical mechanisms, the findings suggest that local vertical circulations play a non-negligible role in extreme climate events. This study is expected to provide a reliable theoretical reference for the prediction of extreme climate events.
The integrated ice sheet response to stochastic iceberg calving
Authors: Ambelorun Aminat , Robel Alexander
Published: March 2024

Iceberg calving is one of the dominant sources of ice loss from the Antarctic and Greenland Ice sheets. Iceberg calving is still one of the most poorly understood aspects of ice sheet dynamics due to its variability at a wide range of spatial and temporal scales. Despite this variability, current large-scale ice sheet models assume that calving can be represented as a deterministic flux. Failure to parameterize calving accurately in predictive models could lead to large errors in warming-induced sea-level rise. In this study, we introduce stochastic calving within a one-dimensional depth-integrated tidewater glacier and ice shelf models to determine how changes in the calving style and size distribution of calving events cause changes in glacier state. We apply stochastic variability in the calving rate by drawing the calving rate from two different probability distributions.e also quantify the time scale on which individual calving events need to be resolved within a stochastic calving model to accurately simulate the probabilistic distribution of glacier state. We find that incorporating stochastic calving with a glacier model with or without buttressing ice shelves changes the simulated mean glacier state, due to nonlinearities in glacier terminus dynamics. This has important implications for the intrinsic biases in current ice sheet models, none of which include stochastic processes. Additionally, changes in calving frequency, without changes in total calving flux, lead to substantial changes in the distribution of glacier state. This new approach to modeling calving provides a framework for ongoing work to implement stochastic calving capabilities in large-scale ice sheet models, which should improve our capability to make well-constrained predictions of future ice sheet change.
A new workflow for revising the seismicity catalog for mainland France, covering the period 2010-2018
Authors: Grunberg Marc , Lambotte Sophie
Published: March 2024

In the continuation of the work carried out over the period 1962-2009 as part of the SI-Hex project, work is on going to revise the seismic catalog of mainland France from 2010 to 2018. This time period is characterized by both an upgrade of short-period stations with broadband stations and a major deployment of new broadband stations as part of the Résif-Epos research infrastructure (now called Epos-France), significantly increasing the amount of detected and processed events.This catalog will benefit from our advances in the use of new artificial intelligence tools, such as PhaseNet, a deep learning automatic picking method, as well as in the development of a deep learning method for discrimination between earthquakes, quarry blasts and explosions.This catalog will be built from those of the national observation service BCSF-Renass, CEA/LDG and regional seismological observatories (Isterre, OCA, OMP). The earthquake picks from these catalogs will be supplemented by those automatically obtained by deep learning on all the waveforms from the Epos-France (formerly Résif-Epos) stations daily used by BCSF-Renass (as part of its mission to monitor seismicity in mainland France) including stations from neighboring countries (GB, LU, BE, DE, CH, IT, ES), as well as those from temporary network stations (AlpArray, CifAlps2). The process workflow includes several steps. The first one consists in a clustering of picks close in time to reduce the amount of picks to process; duplicated picks are removed and priority is given to the manual ones. The second step is the association of seismic phases to create events, by combining the HDBSCAN algorithm - to merge picks close in time and space - with the PyOcto one - to discard picks that did not follow typical travel-time curves. The third step consists in event location using NonLinLoc algorithm with several regional models chosen based on the prior location obtained from PyOcto. At the last step, a moment magnitude Mw is computed (when possible) from waveform spectral fitting using a modified version of SourceSpec. To compute robust magnitudes in particular for low magnitude events, we include magnitude station corrections computed from statistics on magnitude differences between event and stations. Finally, events information (ie. origins, magnitudes) coming from the various catalogs are integrated into the multi-origin catalog according to the QuakeML standard, with the preferred location being the new one computed on the third step.This catalog currently under revision will represent an update of seismicity in France over the period 2010-2018. Preliminary results show that it will incorporate a significantly increased number of low-magnitude events, detected thanks to the inclusion of picks from artificial intelligence tools. Event labeling is consolidated using our deep learning discrimination algorithm, and a Mw magnitude is calculated for each event using waveforms.
Simulating Antarctic Ice Sheet evolution through the mid-Pleistocene transition
Authors: Wirths Christian , Hermant Antoine , Stepanek Christian , Sutter Johannes , Stocker Thomas
Published: March 2024

Unravelling the main drivers of the mid-Pleistocene transition (MPT; around 1.2–0.8 million years ago) remains a significant challenge in paleoclimate research. Noteworthy changes that occurred in the climate system during that time include a pronounced shift from 41-kyr to 100-kyr periodicity of glacial cycles and the emergence of much larger ice sheets. While a number of studies have focused on the interplay between the climate system and northern hemispheric ice sheets during the MPT, the role of Antarctica in driving and responding to climate change at that time remains largely unknown. This is particularly relevant as, consequently, the response of Antarctica’s vast ice sheets to a major transition in Quaternary climate, and their potential role in shaping the transition, remain uncertain. 
Here, we use the Parallel Ice Sheet Model (PISM) to simulate the transient evolution of the Antarctic Ice Sheet through the MPT. Computation of the evolution of ice sheets in PISM is enabled by means of a climate index approach that is based on snapshots of climatic conditions at key periods. The climate index approach interpolates between individual climate snapshots based on various paleo-proxy records. Further, we test Antarctica's response to different pre-MPT GCM snapshots of different CO2, orbital, and land-sea mask configurations. Climate snapshots are derived from the Community Earth System Models (COSMOS), a general circulation model that simulates atmosphere, ocean, sea ice and land vegetation in dependence of reconstructions of paleogeography, orbital configuration, and greenhouse gas concentrations.  

Our study aims to better understand the evolution of the Antarctic Ice Sheets during the MPT and to constrain potential dynamical transitions in the climate-cryosphere system. Furthermore, we seek to clarify the influence of different pre-MPT ice sheet configurations on simulated characteristics of this transition.  

The findings from this study will contribute to an improved understanding of cryospheric changes that occurred during the Quaternary. Furthermore, we aim to provide insights into potential future Antarctic trajectories under anthropogenic climate change. 
Analysis and Research on Hydraulic Characteristic Parameters and Related Sensitivity Changes of Groundwater Layers during Pumping Tests
Authors: Kuo Jen-Tsung , Wen Jet-Chau
Published: March 2024

Sensitivity analyses are an important component of modeling test, which represents the process of evaluating the sensitivity of groundwater flow to changes in hydraulic parameters. This can useful to understand the operating rules of the groundwater system. The major research area including regulating the transport of hydrogeological contamination, planning groundwater protection measures before land development and managing groundwater resources.In this study, we choose to use the adjoint equation method to conduct the sensitivity analysis of the simulation field, which is used to analyze the sensitivity of the head to the model parameters (transmissivity and storativity) in the case of pumping under a two-dimensional transient heterogeneous groundwater parameter field. we will also consider the spatial correlation of the parameter field, which is often ignored in previous literature. In groundwater sensitivity analysis, spatial correlation can effectively improve the efficiency of the analysis and reduce the total computational cost in the adjoint equation method.And then we will perform dimensionless analysis on the analytical solution that has been derived. This will make the analysis method no longer affected by the physical meaning, so that the equation can be applied to different situations without the need to re-derive or calculate, thus increasing the application range of the model.The results will be numerically verified with the VSAFT2 numerical model, which is developed based on the adjoint method. A multi-well work area will be created that can simultaneously calculate the sensitivity coefficient change rate of multiple observation wells and a single pumping well. This will help to more effectively simulate the water flow and sensitivity at the field pumping site, and effectively expand the results of previous literature that only studied dual-well experiments. 