bluuebunny/crossref_metadata_2025 huggingface dataset:
Organic pollutants leaching in agricultural field: patterns in groundwater and subsurface water
Authors: Nussboim Shulamit , Rein Moshe Orah Felicia , Volk Elazar , Larrone Jonathan B. , Wittenberg Lea
Published: March 2024

Organic pollutants contain a variety of compounds that emerge from pest control as well as irrigation with treated effluents. Physico-chemical properties, as well as the history of application, determine distribution in flowpaths. Field-scale research, concentrated on common compounds or included many pesticides, yet analysis did not take the advantage of multiple behavior ranges of many compounds. Rarely short-term time series were collected for organopollutants.In the current research subsurface and groundwater samples were collected from agricultural fields having subsurface drainage systems. Appling subsurface water in conditions of floods during winter required a demonstration of the subsurface unique composition, to avoid using samples including mixing with streamwater or groundwater. Samples were collected before, during, and after storm resulting in time series for subsurface and groundwater. No pest control intervention was taken thus results demonstrate authentic filed conditions. Analysis of time series in this study showed patterns indicating transport processes in the subsurface such as piston flow and leaching of stormwater, occurring in two stages of the storm. This result was supported as well in clustering analysis: clustering clearly showed different compositions of water samples taken in each stage. The clustering demonstrated as well differences between runoff, subsurface and, groundwater, as well as differences between adjacent fields.
Combating air pollution significantly reduced air mercury concentrations in China
Authors: Feng Xinbin , Fu Xuewu , Zhang Hui
Published: March 2024

Long-term observations of atmospheric mercury are important for the evaluation of the effectiveness of the Minamata Convention on Mercury. We continuously measured gaseous elemental mercury (GEM) concentrations at four remote sites in China for more than ten years, i.e., Mt. Waliguan (100.90° E, 36.29° N) during 2008-2022, Mt. Changbai (128.11° E, 42.40° N) during 2008-2022, Mt. Ailao (101.02° E, 2453° N) during 2011-2022, and Mt. Damei (121.57° E, 29.63° N) during 2011-2022. Our observations showed that GEM concentrations in China increased slightly during 2008-2013, and then the GEM concentrations decreased significantly after 2013. The mean GEM concentrations at the four Chinese sites during 2022 were 1.51 ± 0.35 ng m-3, which is close to mean concentrations observed in Europe, North America, the Arctic, and the free troposphere in Pacific Ocean during 2021 (Individual means: 1.14 to 1.51 ng m-3, overall mean: 1.34 ± 0.11 ng m-3, n = 13). During 2013-2022, GEM concentrations in China decreased by 35%, which was much higher than the decreasing rates observed in Europe (9%), North America (10%), the Arctic (6%), and the free troposphere in Pacific Ocean (9%) during 2013-2021. The declines in in GEM concentrations in China since 2013 matches well with the decreasing anthropogenic Hg emission in China estimated by Chinese anthropogenic Hg emission inventory, indicating the reduction in anthropogenic Hg emissions in China was the major driver for the GEM declines.
High-resolution seismic imaging of the sub-bottom Quaternary deposits revealed an active fault in the Vinodol-Velebit channel (Kvarner, Croatia)
Authors: Korbar Tvrtko , Hasan Ozren , Brunović Dea , Markušić Snježana
Published: March 2024

Kvarner area belongs to the External Dinarides fold-and-thrust belt that is characterized by intensive tectonic deformations of a few kilometers thick sedimentary cover of the central part of the Adriatic microplate. The main deformations occurred predominantly during Eocene to Oligocene thin-skinned tectonics, while late-orogenic thick-skinned deformations and wrenching resulted in the exhumation of the orogenic belt. The latter tectonic mechanism is supposed to be still active, but there is no reported evidence of active faults on the surface of predominantly karstic terrain. Nevertheless, seismological data reveal subsurface activity along various fault plane solutions, and crucial evidence of possible active deformations on the surface is expected within stratified superficial deposits in the area. However, stratified Quaternary sediments are rare onshore and on the Kvarner islands but are widespread on the bottom of the surrounding Adriatic Sea. During the targeted high-resolution sub-bottom geoacoustic seismic survey we focused on the zones that are characterized by earthquakes and on the previously arbitrarily recognized regional seismogenic sources. However, only shallow seismic profiles along and across the Vinodol and the NW part of the Velebit channel revealed clear evidence of fault-related deformations of the youngest Quaternary sediments. The fault zone is up to hundreds of meters wide, limited by parallel sub-vertical fault planes, and characterized by deformations of the strata between the planes either in a positive (uplifted) or a negative (downthrown) manner along the strike, which are typical for strike-slip faults. Besides, the disturbed layering of the uppermost well-stratified unit (Late Pleistocene) resembles fluid/sediment escape structures that could be related to strong shaking during prehistorical earthquakes. The fault zone is also tentatively recognized in the onshore bedrock along the strike of the submerged fault, where it appears as an indistinct fractured zone that is more corroded than surrounding bedrock carbonates. Therefore, sub-bottom profiling has been proven to be a useful tool for identifying active faults and should be used as a key method in future seismotectonic research of submerged seismogenic zones.
The critical role of optimal forest management in China for meeting its wood demand and climate target
Authors: Zhang Haotian , Zhao Hao , Lauri Pekka , Forsell Nicklas , Havlik Petr , Chang Jinfeng
Published: March 2024

China’s demand for wood and forest products continues to grow with the booming papermaking industry and residence use, leading to a dramatic increase in imports of wood products. Meanwhile, woody biomass for bioenergy with carbon capture and storage (BECCS) has been projected as a pivotal negative emission strategy in meeting climate goals in the future. However, the imposition of natural forest ban and the pursuit of future climate targets may create additional gaps in the availability of forestry products. Here, we use the GLOBIOM-China model to assess the impacts of diverse woody biomass demands, national programs for afforestation and forest plantation, and management measures in China under climate targets. The results indicate an increase in domestic roundwood consumption by 20.3~50.3 million m3 in 2050 under 1.5℃ scenario compared to that under the baseline scenario (BAU) without BECCS demand, with increased proportion for wood fuel uses and less for pulp and sawn wood consumption. Domestic production fails to meet the energy and material demands for woody products by 2060, necessitating an additional import of 63~144 million m3 of roundwood compared with the BAU, approximately accounting for 29~46% of domestic production. Enhancing logging potential can help prevent the continued transformation of natural forests into managed forests and forest plantations on cropland, as well as reduce roundwood imports by 55-89 million m3, when compared to the management of forests under normal increments. Moreover, such productivity enhancement could contribute to an additional sequestration in forestry of 0.1-1.26 Gt CO2 by 2060. This study underscores the imperative for enhanced forestry system management in China to effectively meet its ambitious climate commitments.
Wildfire, vegetation, and climate history of central Taiwan from the end of the last glaciation to the late Holocene
Authors: Rahman Abdur , Chang Yuan-Pin , Li Hong-Chun , Chung Ling-Ho , Wang Liang-Chi
Published: March 2024

Climate change is expected to lead to an increased frequency of wildfires within forest ecosystems. To accurately anticipate the ramifications of climate change on forests, a comprehensive understanding of the ecological processes governing fire dynamics—specifically intensity, size, and type—is essential. However, the scarcity of long-term data on the intricate relationship between climate, fire, and vegetation dynamics presents a considerable challenge. In this study, a long-term relationship between wildfire, vegetation has been investigated, and climate in the central Taiwan region, spanning from the late glacial period to the late Holocene. For this, multiple proxy approach, including charcoal (CHAR and fire frequency), pollen data, and the carbon isotopic composition of total organic carbon, have been followed. The current study revealed that wildfire largely occurred during the drier climate conditions in the Taiwan region, which attributed to El-Nino like situation in region. Furthermore, it has been observed that from the late glacial period to the late Holocene, there was a shift in biofuel sources from woody plants to herbaceous plants, with a sharp change at the beginning of the Holocene. High fire frequency and intense wildfires were observed during the late glacial period, attributed to a drier climate. On the other hand, higher fire frequency and more intense wildfires during the late Holocene were attributed to human-induced wildfires in the central Taiwan region. 
Mangrove stem methane emissions significantly offset global blue carbon sequestration
Authors: Wang Faming , Qin Guo Ming , Macreadie Peter , Sanders Christian
Published: March 2024

Wetlands, including mangrove forests, are major contributors to global methane (CH4) emissions, a potent greenhouse gas. Recent evidence suggests that CH4 emissions from tree stems may play a significant role in the global carbon budget. This study investigated stem CH4 emissions in mangroves. We find that stem CH4 emissions are greatly neglected in mangroves, and can significantly offset their blue carbon function. The stem CH4 flux rates are well correlated with wood density and wood water content, with lower wood density and higher wood water content facilitating higher emissions. Additionally, stem CH4 emissions are influenced by hydrological conditions, with higher emissions observed under high tidal levels. It is worth noting that the majority of stem CH4 emissions originate from the soil, as evidenced by the strong correlation between stem CH4 emissions and soil CH4 flux. Based on literature synthesis and data integration, we extrapolate our findings and estimate that mangrove stem CH4 emissions on a global scale amount to approximately 0.31 Tg yr-1. This highlights the potential of stem CH4 emissions to partially offset blue carbon burial rates in mangroves, with an average offset of 15.2%. These findings emphasize the importance of incorporating stem CH4 emissions into future blue carbon budgets for mangroves.
 
Using Artificial Neural Networks to upscale soil erosion model results from local to regional scale. An example from Crete, Greece.
Authors: Alexakis Dimitrios D. , Polykretis Christos
Published: March 2024

Soil erosion constitutes an increasing threat to soil productivity and food security. This work describes the potential of using Artificial Neural Networks (ANN) for upscaling soil loss outputs from medium to low scale. The Revised Universal Soil Loss Equation (RUSLE) model was implemented to calculate soil loss rates in two scales in Crete, Greece. Specifically, the RUSLE model was applied in six (6) watersheds across the island using medium spatial resolution satellite images (5m), namely Planetscope. These results were used to feed an ANN model to upscale the mesoscale outputs (5m) to regional outputs (30m-island level). The ANN system was trained using spatial environmental parameters such as the Normalized Difference Vegetation Index, Digital Elevation Model, and topographical slope angle. This "optimized" soil loss derivative later made it possible to compare it with the corresponding final derivative of Crete (regional spatial scale), which emerged from the straightforward processing of RUSLE model with the more "coarse" and generalized data as estimated from the  Landsat-8 satellite images (30m). The statistics revealed that the detailed and high-quality soil loss data, as derived from the upscaling process, provide more precise and reliable results.
Using current 3D point clouds as a tool to infer on past geomorphological processes
Authors: Arav Reuma , Filin Sagi , Avni Yoav
Published: March 2024

Examining deposition and erosion dynamics during the late Pleistocene and Holocene is crucial for gaining insights into soil development, erosion, and climate fluctuations. This urgency intensifies as arable lands face escalating degradation rates, particularly in arid and semi-arid environments. Nevertheless, as the destructive nature of erosional processes allows only for short-term studies, long-term processes in these regions are insufficiently investigated. In that respect, the ancient agricultural installations in the arid Southern Levant offer distinctive and undisturbed evidence of long-term land dynamics. Constructed on a late Pleistocene fluvial-loess section during the 3rd-4th CE and abandoned after 600-700 years, these installations record sediment deposition, soil formation, and erosion processes. The challenge is to trace and quantify these processes based on their current state. In this presentation, we demonstrate how the use of 3D point cloud data enables us to follow past geomorphological processes and reconstruct trends and rates. Utilizing data gathered in the immediate vicinity of the UNESCO World Heritage Site of Avdat (Israel), we illustrate how these point clouds comprehensively document the history of soil dynamics in the region. This encompasses the initial erosion phase, subsequent soil aggradation processes resulting from anthropogenic interruption, and the ongoing reinstated erosion. The unique setting, which uncovers the different fluvial sections, together with the detailed 3D documentation of the site, allows us to develop means for the reconstruction of the natural environment in each of the erosion/siltation stages. Therefore, by utilizing the obtained data, we can recreate the site during its developmental stages till the present day. Furthermore, we utilize terrestrial laser scan data sequence acquired in the past decade (2012-2022) to compute current erosion rates. These are then used to determine past rates, enabling inferences about the climatic conditions prevalent in the region over the last millennium. The in-depth examination of these installations provides valuable insights into approaches for soil conservation, sustainable desert living, and strategies to safeguard world-heritage sites subjected to soil erosion. As the global imperative to address soil erosion intensifies, this case study gains heightened relevance.
The geochemical evolution of an extreme rejuvenated lava: A case study on Aitutaki of the Cook-Austral island chain  
Authors: Rogers Angus , Nebel Oliver , O'Neill Hugh , Yaxley Greg , Nebel-Jacobsen Yona , Wang Xueying
Published: March 2024

Aitutaki is a basaltic Ocean Island in the South-Central Pacific Ocean, a region densely populated with age-progressive islands and seamounts considered to be a result of three or more overlapping mantle plumes. Recent (~1.9 Ma) volcanic activity at Aitutaki is difficult to reconcile with direct melting of a mantle plume, and may instead be an example of rejuvenation, whereby volcanism reappears after an extended hiatus. We have analysed samples of 21 lavas collected from Aitutaki for whole-rock major and trace elements and radiogenic isotopes, with electron probe microanalysis (EPMA) of olivine crystals and xenocrysts. Whole-rock MgO in these samples ranges from 10.3 to 13.9 wt. %. Petrographic examination and EPMA data indicate olivine accumulation is not the cause of these high values. Evidently, very little fractionation occurred during melt ascent through the volcanic plumbing network. Direct eruption of high-MgO (>10 wt.%) primitive magma is unusual in Ocean Island basalts, except among rejuvenated volcanics.Our radiogenic isotope data closely overlap in Pb-isotope space with the nearby Samoan rejuvenated lavas from Savai’i and Tutuila, and otherwise have an EM1-FOZO signature. The major elements, trace elements and radiogenic isotopes all distinguish two populations of lavas, indicating the lavas are sourced from different regions or source materials in the asthenosphere. By analysing the spatial distribution of these chemical anomalies on the island, we observe the least evolved and most trace-element enriched samples (lowest SiO2, highest Th/Y) concentrate in geographically distinct regions on the island. Without a geochemical continuum between these two populations, we suggest the surface distribution of the enriched and depleted lavas may reflect spatial isolation of the mantle sources. Aitutaki produced multiple pulses of geochemically diverse lavas with extreme compositions throughout a short-lived (~50 ka) rejuvenated eruption cycle, exemplifying the processes responsible for producing rejuvenated lavas and challenging our understanding of the petrogenesis of such volcanism.
Exploring ML-based decadal predictions of the German Bight storm surge climate
Authors: Krieger Daniel , Brune Sebastian , Baehr Johanna , Weisse Ralf
Published: March 2024

Storm surges and elevated water levels regularly challenge coastal protection and inland water management along the low-lying coastline of the German Bight. Skillful seasonal-to-decadal (S2D) predictions of the local storm surge climate would be beneficial to stakeholders and decision makers in the region. While storm activity has recently been shown to be skillfully predictable on a decadal timescale with a global earth system model, surge modelling usually requires very fine spatial and temporal resolutions that are not yet present in current earth system models. We therefore propose an alternative approach to generating S2D predictions of the storm surge climate by training a neural network on observed water levels and large-scale atmospheric patterns, and apply the neural network to the available model output of a S2D prediction system. We show that the neural-network-based translation from large-scale atmospheric fields to local water levels at the coast works sufficiently well, and that several windows of predictability for the German Bight surge climate emerge on the S2D scale.
Venus atmosphere dynamics: digging into the Venus Express observations
Authors: Titov Dmitrij , Khatuntsev Igor , Patsaeva Marina
Published: March 2024

Dynamics of the Venus atmosphere is still an unsolved fundamental problem in the planetary physics. ESA’s Venus Express collected long imaging time series in several wavelengths from UV to near-IR. It was later complemented by JAXA’s Akatsuki observations, thus providing the longest almost uninterrupted monitoring of the Venus atmosphere dynamics for about 26 Venus years. Tracking of cloud features allowed determination of wind speed at different levels within the cloud deck thus enabling significant progress in characterization of the mean atmospheric circulation. The analysis revealed wind variability including changes with altitude, latitude, local solar time as well as influence of the surface topography and long term 12.5 years periodicity.The images also provided morphological evidences of dynamical processes at the cloud level. UV dark low latitudes were found to be dominated by convective mixing that brings UV absorbers from depth, while bright uniform clouds at middle-to-high latitudes are typical for the regions with suppresses vertical mixing. The latter feature correlates with drastic increase of the total cloud opacity poleward from ~60° latitude that likely indicates presence of a dynamical mixing barrier here. Similarity of the global UV cloud morphology at the cloud top (~70 km) and that in the deep cloud (50-55 km) observed in the near-IR on the night side suggested similar morphology shaping processes throughout the cloud deck. Venus Express observed gravity waves poleward of 65°N concentrated at the edges of Ishtar Terra likely indicating their generation by wind interaction with the surface. Venus Express performed about 800 radio occultations providing precise measurements of the atmospheric temperature structure and static stability parameter in the altitude range 40-90 km. The Richardson number latitude-altitude field derived from the wind and temperature measurements suggests presence of convection in the cloud deck and stable mesosphere above it with the convective layer extending to greater depth at high latitudes. The talk will present recent results on the atmospheric circulation, supplemented by a summary of the Venus Express observations related to the atmospheric dynamics and an outlook for further analysis of these data.  
Development of a Deep Learning Model for Harmful Algal Blooms Prediction
Authors: Jeong Yookyung , Byun Kyuhyun
Published: March 2024

The risk of harmful algal blooms (HABs) is exacerbated by extreme climate and hydrologic events, as well as the increased non-point pollutant sources associated with agriculture and industrialization. The resulting deterioration in water quality due to the HABs poses significant threats to water management and aquatic ecosystems. HABs, in particular, emerge from intricate chemical interactions influenced by external conditions and diverse hydrologic and water quality factors.  Existing physical models encounter difficulties in predicting HAB occurrences and concentrations due to their limitations in addressing the intricate interactions of external environments and the characteristics of non-linear, non-stationary systems. In response to this challenge, we aim to develop a deep-learning algorithm based on the wavelet transform, with a focus on key hydrologic and water quality factors specific to the Nakdong River in South Korea. We identify water temperature and Chlorophyll-a as pivotal factors influencing HABs. Leveraging the wavelet transform, we extract denoised HAB data to enhance the robustness of our predictive model. Subsequently, we employ Long Short-Term Memory (LSTM) networks to construct a deep learning model, utilizing the identified key factors and denoised data as input features. Our preliminary results demonstrate a decent level of predictive accuracy showing a high Nash-Sutcliffe Efficiency (NSE) value of 0.88 and a low Root Mean Squared Error (RMSE) of approximately 9800 cells/ml, compared to the average HAB quantity of 14474 cells/ml. These outcomes indicate that the developed deep learning approach allows for accurate simulation of HAB. The implications of our research extend to the precise analysis of HABs, enabling the establishment of pre-emptive responses for effective water resources management. Acknowledgment:This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT) (No. NRF-2022R1A4A3032838).
Study on Dust Aerosols Influence on the Retrieval of Solar Radiation During Clear-Sky Periods in the Taklamakan Desert Based on the Accurate Radiative Transfer Model
Authors: Chen Yonghang , Zang Yanbo , Liu Qiong , Wei Xin , Zhao Bingke , He Qing , Gao Tianyi
Published: March 2024

The Taklamakan Desert is not only a major source of dust emissions in East Asia, but also a promising region for the utilization of solar energy resources in China. Dust aerosols are a key factor affecting surface solar radiation in this region. Although numerous studies have utilized models to investigate the impact of dust aerosols on solar radiation, most have depended on aerosol optical depth as the input neglecting the vertical distribution of aerosols. The AccuRT radiative transfer model, which classifies the atmosphere into 14 layers and incorporates aerosol profile information, thus enables a more accurate simulation of the effects of aerosols on surface solar radiation. Based on AccuRT radiative transfer model and CALIPSO satellite observations, the impact of dust aerosols on surface shortwave radiation in the Taklamakan Desert area were analyzed and the surface solar radiation fluxes at the Xiaotang station which is at the center of the Desert were calculated. The results indicated that the influence of aerosol optical depth was the most significant, followed by the ratio of fine particles and their equivalent radius, while the impact of the coarse particle equivalent radius was the weakest. Taking the Xiaotang station as an example, the accuracy of surface solar radiation flux calculated using the AccuRT radiative transfer model was found to be higher than that of the CERES solar radiation data, with the mean absolute deviation reduced by 11.04 W/m², the mean relative error decreased by 0.0320, and the root mean square error lowered by 43.5 W/m². Furthermore, by integrating the aerosol profile information provided by CALIPSO and considering the aerosol stratification scheme, the mean absolute deviation in the surface solar radiation flux calculated using the AccuRT model was reduced by 91 W/m², the mean relative error was decreased by 0.1491, and the root mean square error was reduced by 120.9 W/m².
Anthropogenic influence on flash drought’s impact on terrestrial primary productivity in China
Authors: Zhang Miao , Yuan Xing
Published: March 2024

The increasing flash drought arouses wide attention due to its rapid onset and enormous impact on terrestrial ecosystems. However, the influence of human activities on flash drought’s ecological impact remains unclear. Here we found that there is a significant intensifying ecological response to flash droughts from 1961 to 2014 based on land surface modeling. Furthermore, we attributed the influence of land use and land cover change (LUCC) and anthropogenic influence (ANT) to the intensifying response. Whereas vegetation greening offset the negative flash droughts’ impacts, anthropogenic climate change contributed to the declining resistance of terrestrial ecosystem productivity to flash droughts. This study implies that the land carbon sink is more challenging due to the reduced ecosystem capacity in a warming climate.  
First Initiative in the Arabian Peninsula to Measure Methane Emissions from the Oil & Gas and Waste Sector by a Helicopter Probe
Authors: Huntrieser Heidi , Förster Eric , Pätzold Falk , Bretschneider Lutz , Maier Niclas , Necki Jaroslaw , Bartyzel Jakub , Jagoda Pawel , Witschas Benjamin , Roiger Anke , Lampert Astrid , (be´ah) Oman Environmental Services Holding Company , Lunt Mark
Published: March 2024

Within the framework of the Oil and Gas Methane Partnership 2.0 (OGMP 2.0), initiated by the United Nations Environment Programme (UNEP), companies in the Oil and Gas (O&G) sector have committed to monitor and to reduce their methane (CH4) emissions. Presently, more than 120 companies have joined OGMP 2.0 covering operations in 70 countries around the world, one of which is Oman. Methane is one of the most potent greenhouse gases after carbon dioxide and the focus of worldwide initiatives to combat global warming. This includes UNEP’s International Methane Emissions Observatory (IMEO), which focuses on improved data collection and delivery not only from O&G, but also from other emission sectors including waste. According to Oman’s latest Biennial Update Report, the solid waste sector is the second largest CH4 emitter behind the O&G sector and represents 15% of Oman’s CH4 emissions. However, until now, no sector-specific measurement-based studies on such emissions exist for Oman.Here, we present a novel measurement study, supported and funded by UNEP´s IMEO. The approach involves measuring CH4 emissions from both O&G installations and landfills using the unique helicopter-towed probe HELiPOD equipped with in situ CH4 instrumentation complemented by mobile ground-based CH4 measurements. Quantifications of CH4 mass fluxes from individual sources or clusters can be provided from these measurements. The methodology was deployed during the METHANE-To-Go-Oman field experiment lasting from November to December 2023 in collaboration with partners from the O&G and waste industry in Oman. Within four weeks, more than 70 flight hours were successfully flown with a helicopter in the northern and southern parts of Oman, which required a complex setup. For each of the 26 flights, different flight strategies were implemented depending on the wind situation at the probed sites, which was characterized by a continuously running wind lidar. The HELiPOD probe (weight 325 kg, length 5 m) was equipped with a sensor system measuring the 3D wind vector and in situ instrumentation (Picarro G2401-m and Licor-7700) to measure CH4 with a high precision (1 ppb) and temporal resolution (up to 40 Hz), which is necessary for a precise calculation of the CH4 mass flux. An initial overview of the measurements is presented focusing on a showcase from a landfill.By comparing our collected data (top-down approach) with methane mass flux estimates provided by the industry (bottom-up approach), we aim to assist the involved companies and related governments in prioritizing their methane emission mitigation actions and policies for future endeavours.
Community assessment on user requirements for future satellite gravity missions
Authors: Eicker Annette , Strohmenger Christina , Braitenberg Carla , Kusche Jürgen , Pail Roland , Daras Ilias
Published: March 2024

Since 2002, the GRACE and GRACE-FO satellite gravity missions have been observing changes in the Earth’s gravity field. ESA and NASA are currently planning a double-pair satellite constellation MAGIC, which promises an enhanced spatial and temporal resolution compared to GRACE/-FO. After MAGIC, in the long-term post-2040-time frame, a gravity mission constellation with multiple satellite pairs equipped with novel quantum sensor instrumentation is considered as a promising candidate concept to improve the observation time series even further. It has the potential to acquire unprecedented data on key Earth processes and is expected to significantly expand the potential range of applications.Within the ongoing ESA project “Quantum Space Gravimetry for monitoring Earth’s Mass Transport Processes” (QSG4EMT) an online questionnaire was created to assess user requirements for such a future quantum mission concept. We will present the results of this community assessment based on 135 answers from various user groups (hydrology, oceanography, glaciology, atmospheric and climate sciences, solid earth sciences, and geodesy). In addition to application-driven demands of the different disciplines regarding the required spatial and temporal resolution, accuracy, and latency, we discuss the expected added benefits of hypothetical future mission scenarios and outline possible new application fields.
Modelling approaches to evaluate the role of climate change in landslide activity in Europe
Authors: Gariano Stefano Luigi , Rianna Guido
Published: March 2024

Landslides are natural phenomena of different types, with high randomness and variability. They are triggered or influenced by multiple natural phenomena, among which rainfall plays by far the main role in most areas of the world. A relevant complication in the evaluation of landslide activity is global warming, in particular the related ongoing and expected changes in rainfall and temperature patterns. Indeed, due to larger atmospheric retention capability, an increase in the frequency and magnitude of intense rainfall events was already observed in many areas and more significant changes are expected due to climate change. Given the high spatial and temporal variability of the landslides, climate change can affect them in multiple ways and at different temporal and geographical scales.One of the main approaches used to study the impact of climate change on landslides relies on the adoption of landslide models forced with climate projections generated by physically based, data-driven or hybrid simulation chains. Overall, these studies are based on a similar framework, with a climate modelling chain and a landslide model. The climate chain involves the choice of the Earth System models and concentration scenarios, of a downscaling technique for the production of local assessments, and, in most cases, a bias correction technique with the aim of removing the errors (assumed as systematic) in the assessment of the key climatic variables. The landslide models fed with these variables can be either physically-based (geotechnical, hydrological) or statistical (including empirical analyses or susceptibility assessment), and can operate at different spatial scales, from the slope to the regional/national scale.In the scientific literature, most of the studies that aimed at evaluating the impact of expected climate and environmental changes to landslides considered case studies in the European continent.We analyze fifty articles, book chapters and proceedings that proposed modelling approaches in the study of climate-change-landslide relationships, published between 1999 and 2023. We study the spatial scale, the investigated period (both the control and future periods), and the considered climate and landslide variables. Moreover, we study all the components of the climate modelling chain and the features of the landslide models.We observe an increase in the number of basin-, regional- and national-scale works over the years. In addition, we observe that most of the works focusing on the slope scale are related to the hydro-geotechnical modelling of deep-seated landslides, while most of the basin-scale analyses consider shallow landslides and debris flows and use statistical analyses to model the landslide-climate relationships.
Impact of observed temperature and salinity assimilation in Global Ocean Data Assimilation System (GODAS) using MOM5 
Authors: Rahaman Hasibur , Pokhrel Samir , Kumar Saha Subodh , Penny Stephen , Hackert Eric , Carton James , Rahaman Raheema , Nair T M Balakrishna
Published: March 2024

The National Centers for Environmental Prediction (NCEP) produces operational ocean reanalysis products based on the Global Ocean Data Assimilation System (GODAS) with the Modular Ocean Model (MOM3) as a physical model and 3D-Var as the data assimilation method. Subsequently, the Indian National Centre for Ocean Information Services (INCOIS) has also operationalized the same GODAS system with MOM4p0d as a physical model to produce ocean analysis since 2013. In this study, we upgraded GODAS with MOM5 to produce ocean reanalysis with NCEP-R2 atmospheric forcing. The improved reanalysis is compared with respect to the EN4 analysis and Ocean Reanalysis System 5 (ORAS5) for the subsurface temperature and salinity. The microwave-based satellite-derived sea surface temperature (SST) is employed for the independent evaluation of the reanalysis SST products. We have assimilated observed temperature and salinity profiles from all in situ platforms over the global ocean and assimilated along-track sea level anomaly from altimeter (Jason1 and Jason2) to produce the improved reanalysis. There is a significant improvement in the sea surface temperature (SST) with biases of temperatures reduced from 1.5 °C to ~0.2 °C as compared to without assimilation. Moreover, a significant improvement is found in the subsurface temperature and salinity fields over the northwest Atlantic and Pacific Ocean, Nino 3.4, and Indian Ocean thermocline ridge regions as well. The biases in this new, improved reanalysis are even lower than ORAS5 when compared with EN4 analysis. Thermocline depth also shows improvement in terms of better representation and capturing seasonal variability. We also show the improvement in the new reanalysis with respect to the old reanalysis based on MOM4p0d.
Reconstructing Reservoir Storage of Indian Large Dams using Hydrological Model and Deep Learning Algorithms
Authors: Vegad Urmin , Mishra Vimal
Published: March 2024

Reservoirs play a pivotal role in mitigating floods and regulating river flows, particularly during irregular flows. In India, there are 6,138 large dams, yet only 119 are monitored by the Central Water Commission (CWC). In addition, the observations are available only from the year 2000 onwards. The long-term reservoir storage data are used in water management planning and flood control operations. It can also be used in calibrating hydrological models. However, long-term reservoir storage observations for the large dams in India are still lacking. We used hydrologic and hydrodynamic model framework to simulate the daily long-term reservoir storage data. We included more than 150 dams within the state-of-the-art Catchment-based Macroscale (CaMa) Flood model and generated the model simulated reservoir storage data. Further, we used the Long Short Term Memory (LSTM) algorithm to improve the model simulations using observations from CWC. We used the Global Reservoir Storage (GRS) data as observations for the dams not monitored by CWC. We intend to assess the application of the combined framework of the hydrological model and deep learning technique in simulating reservoir storage. Furthermore, we intend to analyse the long-term changes in the basin hydrology and the reservoir seasonal cycle. Long-term reservoir storage data can be utilized to plan water management and adaptation to climate change.
Solar magnetic field and the correlation between sunspot activity and Earth atmospheric parameters
Authors: Georgieva Katya , Veretenenko Svetlana , Kirov Boian , Asenovski Simeon
Published: March 2024

Sun is the main energy source in the vicinity of the Earth. The terrestrial atmosphere is governed by the energy it receives from the Sun. Many studies during the last two centuries have demonstrated correlations between solar activity and atmospheric parameters.  The problem is that these correlations, even if highly statistically significant, are not stationary. They may strengthen, weaken, disappear, and even change sign depending on the time period.In earlier studies it has been found that the sign of the correlations in the Northern hemisphere depends on the prevailing large-scale atmospheric circulation. According to the Vangengeim–Girs classification, there are three main forms of atmospheric circulation: W (zonal or westerly), C (meridional), and E (easterly) for the Atlantic–Eurasian sector, as well as three similar forms: Z, M1, and M2 for the Pacific–American sector. It has been also found that the reversals of the correlations between solar activity and atmospheric parameters is preceded by (or coincides with) the turning points in the evolution of the large-scale circulation forms and mainly of the meridional forms C and M1.The epochs of large-scale circulation are in turn affected by the stratospheric polar vortex (a large-scale circulation pattern in the stratosphere which develops during polar winter), so the changes in circulation epochs may be associated with the changes in the state of the vortex which can affect the troposphere-stratosphere interaction via planetary waves. If the zonal wind velocity in the vortex exceeds a critical value, planetary waves propagating upward can be reflected back to the troposphere. Under a weak vortex, planetary waves propagate to upper atmospheric levels. Both the circulation epochs and the state of the vortex have cyclic variations with a period of about 60 years.Two types of solar activity agents are supposed to influence the state of the polar vortex: solar UV irradiance, and energetic particles, mostly electrons, which are trapped in the Earth’s magnetosphere and during geomagnetic disturbances are accelerated and precipitate into the atmosphere. They are related to the two components of the solar magnetic field which is the basis of solar activity. These two components have opposite effects on the stratospheric polar vortex. Here we demonstrate that the relative variations of these two components are in antiphase and oscillate with a period of about 60 years, ultimately determining the correlations between sunspot activity and atmospheric parameters.
Probabilistic topology-based analysis of water age at terminal areas in water distribution networks
Authors: Díaz García Sarai , González Pérez Javier
Published: March 2024

The quality of water supplied through water distribution systems is traditionally assured through sampling of different physical, chemical, and biological parameters at the exit of water treatment works and at different locations within the network. However, sampling is periodic and does not capture the complex processes that take place within the network over time and space. The time of residence of the resource within the network (also called water age) has been used in the past as surrogate indicator for water quality (Machell and Boxall, 2012). As water age increases, water quality parameters tend to worsen (Machell and Boxall, 2013). This is more likely in terminal and meshed areas with low renovation rates (high water age). This work presents a detailed analysis of residence times at a terminal branch. This benchwork branch is inspired in the real topology of water connections at several dead ends in a water supply network in Spain. Stochastic demands are simulated per water connection thanks to a demand model inspired in SIMDEUM (Blokker et al., 2010). Demands are then used to run a hydraulic and water quality model with high resolution. Different metrics are then computed to probabilistically assess water age within the branch. These metrics are useful to identify topologies that are especially problematic.Acknowledgements:The authors would like to thank the financial support provided by the Spanish Ministry of Science and Innovation - State Research Agency (Grant PID2019-111506RB-I00 funded by MCIN/AEI/10.13039/ 501100011033; Grant TED2021-131136B-100 funded by MCIN/AEI/10.13039/501100011033) and Junta de Comunidades de Castilla-La Mancha (Grant No. SBPLY/19/180501/000162, funded by Junta de Comunidades de Castilla-La Mancha and ERDF A way of making Europe).References:Machell, J. and Boxall, J. (2012) Field studies and modeling exploring mean and maximum water age association to water quality in a drinking water distribution network. Journal of Water Resources Planning and Management, 138(6), 624-638, https://doi.org/10.1061/(ASCE)WR.1943-5452.0000220Machell, J. and Boxall, J. (2013) Modeling and field work to investigate the relationship between age and quality of tap water. Journal of Water Resources Planning and Management, 140(9), 04014020, https://doi.org/10.1061/(ASCE)WR.1943-5452.0000383Blokker, E.J.M., Vreeburg, J.H.G. and van Dijk, J.C. (2010) Simulating residential water demand with a stochastic end-use model. Journal of Water Resources Planning and Management, 136(1), 19-26, https://doi.org/10.1061/(ASCE)WR.1943-5452.0000002
Tracing colloidal co-transport in porous media with tailor-made polymers
Authors: Kwarkye Nimo , Ritschel Thomas , Totsche Kai
Published: March 2024

The soil aqueous phase contains a multitude of dissolved as well as colloidal substances, e.g., organic colloids and clay minerals. Due to their ability to facilitate co-transport, colloids significantly contribute to the fluxes of carbon, nutrients, and contaminants, which renders a thorough consideration of colloids and their mobility a prerequisite for an understanding of soil matter exchange. However, a comprehensive assessment of colloidal transport is often hampered by the heterogeneity of reactions at soil mineral interfaces and the compositional and functional diversity of organic matter in natural soil suspensions. We addressed this challenge by using tailored organic polymers based on poly(ethylene glycol) (PEG) with high reactivity towards clay minerals. Hence, the polymers may be immobilized when clays are exposed on pore walls or mobilized when clay minerals form a colloidal suspension that permits a co-transport of clays and polymers. To unravel the competition between these mechanisms, we investigated the separate and combined transport of PEG and bentonite in column experiments using natural limestone as substrate. Here, PEG was strongly retarded due to adsorption on clay mineral surfaces that were exposed following limestone weathering. In contrast, PEG was highly mobile when transported simultaneously with bentonite and the observed PEG breakthrough resembled that of bentonite, indicating PEG was co-transported. This demonstrates that the application of PEG is promising in the disentanglement of complex transport phenomena in natural porous media, particularly if competition between adsorption sites is decisive for the fate of organic matter.
Simulating Long-Term Morphological Changes in the Nakdong River Estuary: Evaluating the Effects of Restoration Initiatives
Authors: Lee Guan-hong , Chang Jongwi , Harris Courtney
Published: March 2024

The Nakdong River Estuary (NRE) in Korea has undergone significant anthropogenic alterations, including the construction of two estuarine dams and the reclamation of approximately 17 km2 of tidal flats. These modifications have shifted the depositional environments from tidal-dominated to wave-dominated, leading to the formation of barrier islands from sand shoals at the estuary entrance (Williams et al., 2013, Marine Geology). Recently, the Korean government has initiated a controlled restoration project at the NRE. This study aims to assess the long-term effects of restoration on morphological changes in the estuary. We conducted simulations using a calibrated COAWST modeling system over a decade, assuming the absence of estuarine dams and land reclamation (Chang et al., 2020, Marine Geology). Surprisingly, our simulations revealed the re-establishment of the ebb-tidal delta where barrier islands formed after the dam construction. Additionally, the sediment texture underwent a notable shift from mud-dominated to sand-dominated, attributed to increased current velocities within the estuary. These sedimentary changes exhibited a longer time-scale, while the hydrodynamic changes from a wave-dominated to tide-dominated system had immediate effects. These findings carry significant implications for resource managers, especially amidst the growing demand for estuarine restoration. The study underscores the complex interplay between anthropogenic interventions and natural processes in estuarine environments, emphasizing the importance of long-term monitoring and adaptive management strategies for successful restoration initiatives.