bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving Visibility Forecasting during Haze-fog Processes in Shanghai and Eastern China: the Significance of Aerosol and Hydrometeor
Authors: Xie Ying , Wang Xiaofeng , Gao Yanqing , Chen Baode , van der A Ronald , Ding Jieying , Gu Wen , Zhou Min , Wang Hongli
Published: March 2024

Aerosols and droplets are the main factors of visibility reduction by scattering and absorbing light. For visibility predictions in operational NWP models, hydrometeors are often considered to be the dominant factor in the total extinction, whereas aerosol effects are usually simplified or omitted in models developed for relatively clean regions. In China, also many NWP studies related to visibility forecasting during haze-fog processes have been conducted, primarily focusing on severely polluted periods before 2018. These studies often employed visibility parameterizations that considered either aerosol extinction alone or hydrometeor extinction alone. Therefore, the significance of incorporating both aerosol and hydrometeor extinction into visibility forecasting during haze-fog processes remains uncertain, particularly under recent rapid changes in aerosol concentration, composition, and hygroscopicity in China.In this study, we first use the 3-D meteorology fields from the Shanghai Meteorological Service WRF-ADAS Real-Time Modeling System (WARMS) to drive the Community Multiscale Air Quality (CMAQ) model. In this version, CMAQ is used in an off-line mode and visibility is diagnosed by combining extinctions due to hydrometeors and aerosols. Satellited derived NOx emissions using the Daily Emissions Constrained by Satellite Observations (DECSO) algorithm have been incorporated to give more up-to-date emissions. We analyze the results of a one-month forecasting period during the winter of 2021-2022 to assess the model's performance and understand the impact of hydrometeor and aerosol extinction on operational visibility forecasting. We find that for the city of Shanghai, aerosol extinction has a minor impact on the model’s performance when forecasting visibility below 1 km but becomes crucial for predictions spanning 1-10 km. Comparison against observations shows that the model well captures the general contributions from various chemical constituents with nitrate as the most important factor in aerosol extinction (~60%). Furthermore, our assessment of the North China Plain (NCP) highlights that in highly polluted areas aerosols could be significant for visibility below 1 km. Finally, we conduct case studies with the fully coupled WRF-Chem model and compare results with the offline WARMS-CMAQ system. Aerosol effects on fog and visibility forecasting due to feedbacks between aerosols, radiation, and cloud physics will be discussed.
Simulation experiment evaluation and chemical kinetics prediction of the composition of n-alkanes components
Authors: Bo Song , Xue Haitao , Lu Shuangfang
Published: March 2024

          It is pivotal to predict the overall composition of subsurface oil and gas reservoirs to assess their fluidity, phase behavior, and recovery potential. Recognizing the significance of n-alkanes as key constituents of mature oil and gas, this study conducted a thermal simulation experiment of gold tube hydrocarbon generation on the source rock of Gulong Sag. The experiment included comprehensive analysis and measurement of the n-alkanes components in a representative sample. Subsequently, an empirical regression evaluation formula was established to evaluate the n-alkanes composition at various maturity stages. Furthermore, a chemical dynamics model for the formation of individual n-alkanes single molecule components was developed and calibrated based on the principles of chemical kinetics. Combined with the stratigraphic burial history and thermal evolution history of the target area, the distribution and evolution characteristics of n-alkanes components in different evolutionary stages of geological conditions can be quantitatively evaluated and predicted. Moreover, the phase behavior of n-alkanes components can be determined based on the evolution characteristics of these components. Experimental results indicate that the methane yield continues to increase with temperature under both heating rates. Additionally, the yield of n-C to n-C initially reaches its maximum with the temperature increase, and subsequently decreases. Furthermore, the hydrocarbon generation characteristics of n-alkanes follow a Gaussian distribution trend. The kinetic results demonstrate that the activation energy of n-alkanes falls within the range of 190-280 kJ/mol, while the distribution of pre-exponential factors is uneven. By considering the geological conditions, it has been determined that the light component in the Gulong Sag is currently experiencing a favorable generation period, whereas the heavy component has reached its peak formation stage, with some undergoing cracking. The oil and gas produced under these geological conditions exist as single-phase unsaturated fluids within volatile reservoirs. The evaluation value of the experimental regression formula, along with the predicted value from the dynamic model, aligns well with the experimental data, providing a solid foundation for the geological application of the model. Therefore, this research serves as a stepping stone towards furthering our understanding of hydrocarbon composition prediction, as well as evaluating phase behavior, mobility, and recovery of underground oil and gas in conjunction with geological conditions. 
Mechanisms of soil organic carbon accumulation driven by karst vegetation restoration 
Authors: Zhang Wei
Published: March 2024

With the support of ecological restoration projects, the karst region of Southwest China is now recognized as a hotspot for "Greening Earth" and a major contributor to vegetation carbon (C) sinks in China. However, the function of soil C sequestration in the region and its driving mechanisms are not well understood. To address this gap, we first selected 362 fixed locations within a typical karst catchment to examine alterations in soil organic C (SOC) content and density before and after cropland restoration. We found that both natural (39 g C m–2 yr–1) and managed vegetation restoration (18–27 g C m–2 yr–1) significantly increased SOC accumulation rates. Surprisingly, bedrock exposure ratio, traditionally viewed as a limiting factor for soil C sequestration, indirectly contributes to SOC accumulation by influencing initial soil C pools, external nitrogen inputs, and soil calcium content. Furthermore, we extended our analysis to scrutinize SOC fractions and their determinants in karst (carbonate rocks) and non-karst (clastic rocks) forest soils across a climatic gradient in Southwest China. For comparative purposes, adjacent croplands with a history of long-term soil tillage were included. We found that both SOC and mineral-associated organic C (MAOC) contents, as well as microbial necromass C content, were higher in karst forest soils compared to non-karst. Notably, MAOC in karst soils displayed lower sensitivity to warming than non-karst soils. Our results revealed that karst vegetation restoration, by augmenting mineral protection mediated by calcium and modulating microbial life history strategies (shifting from r-strategy to K-strategy), fosters the accrual of microbial necromass C, thereby facilitating SOC accumulation. In conclusion, our findings underscore the substantial potential of karst vegetation restoration-driven soil C sinks and emphasize the pivotal role of rapid weathering of carbonate rock in soil C accumulation.
Selecting representative climate models for climate change impact studies: A case study of the eastern Omo basin
Authors: Woldesenbet Tekalegn Ayele , Elagib Nadir
Published: March 2024

 Selecting representative climate models for climate change impact studies: A case study of the eastern Omo basinTekalegn Ayele Woldesenbeta b, Nadir Ahmed Elagiba a Institute of Geography, Faculty of Mathematics and Natural Sciences, University of Cologne, Cologne, Germanyb Ethiopian Institute of Water Resources, Addis Ababa University, Addis Ababa, EthiopiaAbstractSelecting reliable general climate models (GCMs) is crucial for assessing the impact of climate change in a region. The current study evaluated the performance of 34 GCMs from the Coupled Model Intercomparison Project Phase 6 (CMIP6) in simulating monthly total rainfall. To this end, the case of eastern Omo basin was considered with observed rainfall data at seven meteorological stations for the period 1985–2014. The corresponding GCM-simulated rainfall data were compared using seven performance metrics. Eight performance metrics were selected under four categories as follow: error metrics (mean bias error, mean absolute error, root mean squared error), model efficiency (Nash and Sutcliffe’s model efficiency, absolute model efficiency, Kling-Gupta model efficiency), indices of agreement (modified index of agreement), and goodness of fit (coefficient of determination). Three key results were obtained: 1) There is no single best overall GCM across the meteorological stations using a single performance metric, 2) No single best GCM was found for a meteorological station using all the performance metrics, and 3) Based on all performance metrics across all the meteorological stations, the best GCMs in order of performance are SAM0-UNICON, TaiESM1, INM_CM5_0, AWI_ESM_1_1_LR, and CMCC_CM2_HR4. The selected GCMs can be used for evaluating the impact of climate change on hydrology, water resource availability, ecological flow regime and for climate adaptation and mitigation strategies.Keywords: performance metrics, CMIP6, rainfall, climate models, ranking, Omo basin,
Fertilization turns a rubber plantation from sink to methane source
Authors: Epron Daniel , Chotiphan Rawiwan , Duangngam Ornuma , Wang Zixiao , Shibata Makoto , Paul Sumonta Kumar , Kasemsap Poonpipope , Sajjaphan Kannika
Published: March 2024

Soils, particularly in upland forests, are the largest biological sink for atmospheric methane (CH4), providing a valuable ecosystem service. Rubber plantations have continually expanded in Southeast Asia, and it is known that converting forests to rubber plantations reduces soil CH4 uptake. However, the effect of management practices, and in particular fertilization, on the methane balance of a rubber plantation has not yet been studied. Rubber plantations cover almost 10% of the country's surface area and almost all rubber plantations are fertilized, two thirds of them intensively or very intensively.We measured net soil CH4 fluxes over more than a year in a 9-ha experimental rubber plantation with four levels of fertilizer application. We observed a strong and significant reduction of net soil CH4 uptake with increasing fertilisation, which was not explained by differences in CH4 diffusion related to soil water content. Fertilisation not only decreased the methanotrophic activity but also stimulated methanogenic activities probably related to an increase in the availability of nitrogen and labile carbon substrates.Our results show that intensive fertilization turned soil from methane sink to source, particularly during the rainy season. Given the areas cultivated with rubber trees in Thailand and more widely in South-East Asia, a transition towards rational fertilization of plantations would have a significant positive effect on national reporting greenhouse gas inventories.
Perturbation Energetics of the December 2022 Bomb Cyclone over North America
Authors: DeLarme Emerson , Li Jianping , Zhao Hongyuan , Liu Yuan , Sun Ruipeng
Published: March 2024

Bomb cyclones over land are an understudied phenomenon. As such, there are open questions about the underlying physical processes, for example, why do bomb cyclones stop deepening. Atmospheric energetics is a prevalent approach to solve such problems, however the commonly used method of Available Potential Energy is not valid at local scales. Therefore, this study aims to provide further insight into the life cycle of bomb cyclones, specifically over land, by conducting a case study of the bomb cyclone that occurred over North America at the end of December 2022, focusing on the energetics using the Perturbation Potential Energy (PPE) framework. Hourly ERA5 reanalysis data provides the improved time resolution needed to study the evolution of such a rapidly developing system. PPE analysis of the evolution of this bomb cyclone reveals a possible stop signal to the positive feedback loop associated with explosive deepening. Further research is needed to clarify the mechanics associated with this thermodynamic signal.
Regional frequency analysis of the maximum 5-day precipitation in Slovakia using L-moment approach
Authors: Markovič Ladislav , Faško Pavel , Bochníček Oliver
Published: March 2024

Understanding the patterns of extreme precipitation is crucial for effective water resource management, infrastructure design, and flood risk assessment. This study offers a comprehensive analysis of the maximum annual 5-day precipitation totals (Rx5d) in Slovakia using regional frequency analysis (RFA) to elucidate the probabilistic behavior of these events, essential for informed decision-making amid changing climate patterns. We analyzed 70 years (1951–2020) of precipitation data from 419 stations employing the L-moments approach for regional homogeneity testing and frequency analysis. The data were stratified into homogeneous regions using a multi-regression approach and distance matrices, facilitating the development of regional frequency curves. We employed L-moments ratio diagrams and Anderson-Darling goodness of fit tests for extreme-value distributions. Our methodology delineated 14 distinct regions, with the generalized logistic distribution identified as the most suitable approximation for Rx5d in 11 out of the 14 clusters. The study suggests that cluster analysis coupled with L-moments-based regional frequency analysis can effectively derive design rainfall estimates for Slovakia. The developed regional frequency curves are invaluable for estimating return periods of extreme 5-day precipitation events at any location within the study area, proving indispensable for effective flood risk management, infrastructure design, and climate adaptation planning.
Integrating mulching and supplementary irrigation for soil environment improvements in apple orchards of northwest China
Authors: Yang Yuxin
Published: March 2024

Abstract: Mulching and supplementary irrigation are commonly used water-saving techniques ensuring agricultural sustainability in drylands of northwest China. However, the effects of the combination of mulching and supplementary irrigation on the soil environment, and the growth of apple trees remain unclear. Field experiments were conducted in 2023 to evaluate the effects of the combination of mulching and supplementary irrigation on the soil water and heat, and the growth of apple trees. In the experiments, one mulching method (corn straw mulching, SM), two types of drip irrigation, which included above-ground ring drip irrigation (M1) and above-ground two-row drip irrigation (M2), were used. Additionally, three irrigation levels of 100% (W1), 75% (W2), and 50% (W3) of full irrigation (referred to as full, moderate deficit, and severe deficit irrigation, respectively) were used. The results showed that SM significantly increased the soil water content (SWC), especially in the early stage of the growth period. SM significantly reduced and stabilized the soil temperature during the whole growth season, while M1 and M2 had no significant effect on the soil temperature. Both mulching and drip irrigation significantly increased the net photosynthetic rate (Pn) of leaves. Supplementary irrigation had no significant effect on shoot length, but increased shoot diameter. The evapotranspiration of various stages on apple trees was in the following descending order: fruit expansion stage (III), bud development and flowering stage (I), leaf expansion stage (II), and fruit maturing stage (IV). Therefore, SM has the potential to increase apple yields in the Loess Plateau by improving the soil environment and regulating the growth and physiology of apple trees.
From development of multi-sectoral drought hazard indicators to global drought hazard propagation
Authors: Abbasi Neda , Siebert Stefan , Weller Malte , Trautmann Tina , Weber Jan , Vu Tinh , Eyshi Rezaei Ehsan , Kunstmann Harald , Koethe Harald , Lorenz Christof , Döll Petra
Published: March 2024

Droughts pose a substantial threat to various sectors, including agriculture, human water supply but also natural ecosystems. While various studies have been conducted for drought evaluation, the majority of them have focused on a particular drought type. This may lead to a lack of comprehensive understanding of the features and progression of droughts among different drought types through time. For example, for water resources management and planning purposes, it is critical to understand the changes and temporal development of drought signals from abnormal meteorological conditions to soil moisture, groundwater levels, and streamflow. Within the OUTLAST project, which aims at developing an operational, multi-sectoral global drought hazard forecasting system, we develop a near real-time drought hazard monitoring and forecasting system which, for the first time, includes tailored indicators for various sectors, including water supply, riverine and non-agricultural land ecosystems, as well as rainfed and irrigated agriculture. In this context, the primary objectives of this study are to 1) develop different drought hazard indicators (DHI) to monitor and forecast the drought across different sectors; and 2) assess the spread and propagation of droughts across different sectors and regions at a global scale. For this purpose, DHIs were computed for a 40-year reference period (1981 to 2020) using ERA5 as meteorological forcing data to drive the DHIs using the global hydrological model (WaterGAP) and the global crop water model (GCWM). These DHIs cover meteorological (SPEI and SPI), hydrological (empirical percentiles and relative deviations of soil moisture and streamflow), as well as agricultural droughts (crop-specific DHIs for rainfed and irrigated croplands). In this project, we focus on the period 2011 to 2015, with 2012 being a year in which droughts had major impacts on various regions and sectors. The study investigates drought propagation from meteorological drought, extending to rainfed agriculture due to soil moisture deficiency, over streamflow, and eventually reaching irrigated agriculture. In doing so, region-specific features and the dependency of drought propagation on the magnitude of the drought are highlighted. Finally, as monitoring and projecting drought characteristics are important for comprehending drought-related issues, our multi-sectoral drought hazard forecasting system enables us to evaluate the state of drought propagation at a global scale. 
Characteristics for b-value of induced seismicity in Southeast of Sichuan Basin, China
Authors: Xie Mengyu , Zhao Yunxiao , Meng Lingyuan
Published: March 2024

Due to abundant shale gas buried beneath Southeast of Sichuan Basin, China (SBC), hydraulic fracturing operations are implemented since 2008. And large-scale shale gas mining began in December 2014. A rapid increase in the rate of seismicity in SBC since 2015, including the 16 December 2018 MS5.7, the 3 January 2019 MS5.3, the 17 June 2019 MS6.0, the 8 September 2019 MS5.4, the 18 December 2019 MS5.2, the 16 September 2021 MS6.0 and the 6 April 2022 MS5.1 earthquakes. Those earthquakes have caused much damages and many injures, which attracts a lot of attention from society and researchers. The related studies show that seismicity in SBC are induced by or related to hydraulic fracturing operation (Meng et al, 2019; Lei et al, 2019). In this work, we try to study the characteristics of local seismicity and explore the spatiotemporal characteristics of b-value in G-R relation to gain insight into the possible dynamic processes beneath the induced seismicity and assess the seismic hazards. The preliminary results indicate that the average b-value decrease from 1.17 to 0.75 when the 16 September 2021 MS6.0 earthquake occurred. And there is a substantial reduction of b-value before the 8 September 2019 MS5.4 earthquake. Moreover, the temporal variations for b-values don’t show a common pattern. This study was supported by the Science for Earthquake Resilience (XH22011YA), “Real-time analyze characteristics of earthquake sequence by b-value and waveform” and National Natural Science Foundation of China (41974068), “Seismicity for Shale Gas Hydraulic Fracturing Stimulation”. Lei X L, Wang Z W, Su J R. 2019. The December 2018 ML 5.7 and January 2019 ML 5.3 Earthquakes in South Sichuan Basin Induced by Shale Gas Hydraulic Fracturing. Seismological Research Letters, 90(3), 1099-1110, doi: 10.1785/0220190029.Meng L, McGarr A, Zhou L, Zang Y. 2019. An Investigation of Seismicity Induced by Hydraulic Fracturing in the Sichuan Basin of China Based on Data from a Temporary Seismic Network. Bulletin of the Seismological Society of America, 109(1), 348–357, doi: 10.1785/0120180310.
Creation and verification of a multi-parameter surface meteorological dataset for the Tibetan Plateau for 2010-2020, available online
Authors: Wen Xiaohang , Zhu Xian , Li Maoshan , Zhang Shaobo , Yang Xianyu , Zheng Zhiyuan , Yan Dongdong , Zhang Yu , Lv Shihua
Published: March 2024

Abstract: The Qinghai-Tibetan Plateau (QTP) is a crucial component of the global climate system, influencing the regional and global climate through complex thermal and dynamic mechanisms. The high-altitude region, which is the largest part of the extra-polar cryosphere, encompasses extensive mountain glaciers, permafrost, and seasonally frozen land, making it highly sensitive to global climate change. However, the challenging environmental conditions, such as harsh terrain and high altitude, coupled with sparse weather station distribution and weak observatory representation, make it difficult to accurately quantify the atmospheric conditions and land-atmosphere coupling systems and their effects on surrounding areas. To address these challenges, we utilized the WRF model and a 3D-var data assimilation method to create a high-resolution assimilated dataset (HRAD) based on three-dimensional variations. The QTP-HRAD dataset, covering the spatial range of 70 to 110°E and 25 to 40°N, has been validated using both surface weather station observations and European Center for Medium-Range Weather Forecasts Reanalysis V5, and can now be utilized for further studies on land-atmosphere interactions, water cycling and radiation energy transfer processes, and extreme weather events in the region.
Decoupling of East Asian and Indian summer monsoons since the middle of the Late Holocene
Authors: Annapureddy Phanindra Reddy , Gandhi Naveen , Shen Chuan-Chou , Hu Hsun-Ming , Huang Chun Yuan
Published: March 2024

Substantial hydroclimate archives suggest that the Asian Summer monsoon (ASM) is driven directly by summer hemispheric solar insolation on millennial to orbital timescales. In addition, precisely dated speleothems from the two regimes of ASM subsystems show strong coherence between East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) rainfall variability on millennial to orbital timescales. Further, Holocene stalagmites from the ASM domain exhibit a synchronous trend following the northern hemispheric summer insolation general declining trend throughout the Holocene. However, the co-evolution and synchronous variations in the two monsoon domains of ASM were often debated. In this study, the high-resolution oxygen isotope (δ18O) profiles of  two precisely dated stalagmites (hereafter Kadapa composite), collected from the Deccan Indian cave, established with 2913 oxygen isotope data and 60 U/Th ages, provide a continuous history of ISM intensity for the last three millennia i.e., the late Holocene. The Kadapa composite indicates large variability with the disappearance of the declining trend in ISM strength around the middle of the late Holocene, particularly at the end of the Roman Warm Period (RWP). The preliminary analysis using multi-proxy data in and around the subcontinent suggests an abrupt hydroclimate shift at the end of RWP, i.e., ~1.7-1.8 kyr BP and high-resolution stalagmite data from both monsoon regimes reveal decoupling of EASM and ISM since the end of RWP. It is also noted that this hydroclimate shift is not limited to the ASM domain but rather observed from major hydroclimate zones around the globe. However, this hydroclimate shift and decoupling could remain overlooked. This monsoon hydroclimate shift was rapid and took a few decades to a century worldwide and was a departure from the solar insolation-driven drying trend, continuing since the mid-to-late Holocene. Furthermore, the analyses reveal a dramatic increase in positive Indian Ocean Dipole events, ENSO variability, and intensification of El Niño and La Niña events around 1.7-2.0 kyr BP. Combined with different marine and terrestrial records, we suggest that the tropical Indian and Pacific ocean-atmospheric circulation could initialize a mean monsoon climate shift in the middle of the Late Holocene. Though the solar forcing remains one of the factors of orbital to millennial-scale ISM rainfall variation, tropical Indo-Pacific ocean-atmospheric interactions may dominate and dictate the ISM rainfall variability on sub-millennial time scales during weakened Solar Insolation. Additional high-resolution multiproxy paleoclimate and simulations are needed to understand such monsoon climate shifts, to mitigate the future abrupt hydroclimate shifts under the current global warming trend.
Fluid-flux versus decompression melting – the Tonga arc – Lau back arc system
Authors: Beier Christoph , Turner Simon , Brandl Philipp A. , Haase Karsten M.
Published: March 2024

Subduction zones are key regions of mass exchange between the Earth’s crust and mantle, and magmas in the sub-arc mantle form as a result of the release of volatiles from the subducting slab, i.e. fluid-flux melting. Introducing unique geochemical tracers (e.g., Large Ion Lithophile Elements) into the depleted mantle wedge allows tracing of the flow of material underneath the island arcs. Back arc spreading centres form as a result of slab-rollback, and here melts form due to decompression melting similar to those forming at mid-ocean ridges. Back arc systems situated angular to their adjacent island arc encompass a range of slab depths and provide a unique means to assess the compositional changes as a function of distance to the active arc and above the subducting slab. The Valu Fa Ridge (VFR), Eastern Lau (ELSC) and Central Lau (CLSC) spreading centres are situated at an increasing distance from the active Tonga arc from south to north. Here, we present new major, trace and volatile element data along with radiogenic isotope and U-Th-Ra disequilibria along the VFR and ELSC and across the VFR. A systematic change of, e.g., Ba/Nb, Nb/La, H2O contents and Pb isotopes with increasing distance between the back arc and the Tonga arc could be interpreted to reflect the slab-related metamorphic dehydration reactions. However, we do not observe a gradual change in geochemical compositions at a distance 100 km between the arc and back arc, the occurrence of (230Th/238U) excess suggests that melting is due to decompression and that the systematic decrease in subduction influence observed with increasing distance is likely the result of melting of hydrous, ancient slab remnants during rollback. We conclude that the melting regimes between the ELSC and Tonga island arc separate at ~100 km total distance, as evident from the stepwise change in trace element and isotope geochemistry. The decrease in subduction-related signatures along the VFR and ELSC results from an overlap of the melting regimes and melt mixing between the arc and back arc in which the melting of the depleted mantle underneath the back arc becomes more prominent with increasing distance.
Effective vapor transport in snow: The role of convection and the local mass transfer coefficient
Authors: Hidalgo Juan J. , Krol Quirine
Published: March 2024

Mass loss of snow packs due to recrystallization processes and subsequent vapor fluxes are inherently difficult to measure experimentally. Present numerical advances enable new simulation tools to explore the otherwise invisible mass fluxes due to diffusive and convective water vapor transport. In this study we calculate the effective vapor fluxes as a function of the local mass transfer coefficient, snow depth, and a range of microstructure parameters given by porosity and specific surface area. A set of flow, heat transport and vapor transport equations re developed. Heat transport is characterized by the Rayleigh number while vapor transport depends on the Péclet and Damkhöler numbers. The latter measures the relative importance of vapor transfer to advective fluxes. For low Rayleigh numbers, the system behaves in a purely diffusive manner. however, convective transport mechanisms dominate for high Rayleigh values. Convection is found to enhance vapor transport. This is in agreement with previously unexplained mass losses in field observations. The effect of vapor mass transfer between the solid and gas phase is also analyzed. The results can be used for macroscale snow pack models to predict large scale mass loss due to sublimation for snow covered areas such as Antarctica, Greenland and seasonally covered Tundra.
Experience and interpretation in the Geosciences learning process
Authors: Occhipinti susanna
Published: March 2024

This research aims to analyse the data that emerged from a long path of experiences, workshops, projects aimed at schools and a varied audience, with the aim of promoting interest in Geosciences. The fragility that characterizes in many countries the process of teaching and learning Geosciences throughout the educational cycle is certainly not a surprise, even in those countries where environmental emergencies, volcanoes, earthquakes, hydrogeological instability would require an in-depth knowledge of the dangers to reduce and when possible, prevent the risks. Some data will be provided, collected in the IGEO, International Geoscience education Organisation, where I am the contact person for Italy and at IESO, the Earth Sciences Olympiad has allowed me to interact with students and teachers from all over the world and especially through the COGE Committee of geoscience education of IUGS, as head of the GEFO committee with the aim of coordinating the work of field officers in many countries of the world outside Europe. The main role of field officers is to represent and promote IUGS-COGE initiatives among geoscience teachers and educators in their country, providing professional development through interactive workshops for teachers who have elements of geosciences in their curriculum. This can be done through workshops, proposing activities that use easy-to-build tools such as the materials of the ELI-Earth learning Idea repertoire presented at GIFT, which are particularly effective for understanding basic concepts and motivating students and teachers through manipulative approaches. It is clear, however, that the training and orientation path towards studies in the field of geosciences requires a significant progression of tools and concepts, which allows us to understand concepts of complexity and uniqueness, of flows and relationships, of interconnected systems that characterize the ES The research, in agreement with the GEFO COGE, is focusing on this: students 14-18 are often involved in field activities, conferences or academic lectures, but identify and develop activities dedicated to them that can motivate and excite them, making them passionate about this field of research, aware of the importance of these issues, which, in line with the objectives and goals of the 17 Sustainable Development Goals, SDGs, which are the responsibility of geosciences, from natural hazards, to global warming, to energy transition, to strategic minerals, are a priority. Some examples will be proposed, but research requires a considerable impulse and widespread collaboration between schools, universities , and research centres, combining scientific skills of the research world with methodological teaching skills of the education one.
The fate of carbon after photosynthesis and its transit time in forests
Authors: Sierra Carlos
Published: March 2024

Terrestrial ecosystems annually fix about 120 ± 7 Pg of carbon through photosynthesis, with forests being responsible for a large portion of this flux. After photosynthesis, this new carbon has different fates depending on allocation to plant parts and transfers to forest floor and soils. The time it takes carbon to pass through an ecosystem, since photosynthetic fixation until its final release as CO2, is defined as the transit time of carbon. The transit time of carbon can be characterized by continuous probability distributions that indicate where carbon is allocated to, for how long it stays in a certain ecosystem compartment, to what other compartments it is transferred to, and for how long carbon is stored in organic forms before its return back to the atmosphere. In this presentation, I will show why the transit time distribution of carbon is an appropriate metric to answer the question of where does the carbon go? I will present estimates of the transit time distribution of carbon for two tropical forests and for the entire terrestrial biosphere, which indicate that on average carbon only stays stored in ecosystems for about one decade, and with about half of the fixed carbon respired in half a year. I will show a new approach to quantify the mean transit time of carbon based on measurements of radiocarbon in plant parts, soils, and respired CO2; and will show results from a global carbon model that suggests that the transit time of carbon of the terrestrial biosphere is becoming younger, with faster dynamics in tropical and temperate forests, and emissions of older carbon from boreal and arctic regions.  
From hydrocarbons to geothermal energy: a case study from the Dutch subsurface
Authors: Weert Annelotte , Vinci Francesco , Iacopini David , van der Vegt Paul , Tavani Stefano , Ogata Kei
Published: March 2024

The West Netherlands Basin, which has a long history in exploration as a former prosperous hydrocarbon province, is currently a geothermal hotspot. Being exploited since the 1950’s, most of its oil and gas fields are now in their final phase of production. In the past decade, interest shifted to sustainable energy sources. The geothermal industry in the area is developing quickly, helped by the legacy of the hydrocarbon industry: a wealth of publicly available seismic and well data. Currently, the area has 14 realized, and at least 3 projects in the development phase, with the Late Jurassic Nieuwerkerk Formation being the main target.Conversely to petroleum systems, in which anticlines are the preferential target for hydrocarbon exploration, synclines are the most suitable sites for geothermal exploration. They offer higher temperatures with respect to the limbs and anticlines, and possible remaining hydrocarbons are not expected to be located inside the central portions of the synclines.The West Netherlands Basin is a former rift basin that developed during the Mesozoic in the framework of the North Sea rift, and subsequently inverted during the Late Cretaceous. The Nieuwerkerk Formation was deposited during the last major rifting phase. Thus, the thickest packages of its fluvial-deltaic deposits are fault-controlled and commonly located in the synclines. The heterogeneity of fluvial reservoirs causes lateral and vertical quality variations in porosity, permeability and net-to-gross ratios. With the hydrocarbon industry focussing on the stratigraphic highs, there is only limited well data available for the central portions of the synclines.With reprocessed 3D seismic data, our study uses an image processing approach, coupling traditional amplitude mapping with seismic attributes. This will help to reconstruct the evolution of the fluvial architecture of the Nieuwerkerk Formation over time. By tying the seismic with well data, a better prediction of the quality of the sandy bodies per location can be made. These results can be implemented in de-risking geothermal well planning across fluvial reservoirs in inverted rift basins.
Quantifying Contributions from Different Physical Processes to the Atmospheric Warming over the Tibetan Plateau
Authors: Wei Yuying , Wang Yuwei
Published: March 2024

The Tibetan Plateau (TP), known as Earth's “Third Pole”, has experienced significant warming since 1980. As an important component of the summer monsoon, the TP rapid warming profoundly impacts both Asian and global climate systems. While previous studies focused on surface temperature, our research uses multiple reanalysis datasets to investigate atmospheric temperature changes over the TP. All three reanalysis datasets revealed an upper tropospheric warming above the TP centered around 250 hPa. The upper tropospheric warming rate is approximately 0.3 K/decade over the 1980-2021 period, faster than those at the same latitude. An energy budget analysis is performed to attribute this warming to different processes. The primary contribution arises from the convection process, contributing around 0.4K/decade. Cloud warms the upper troposphere by an additional 0.2K/decade. Other radiative processes and adiabatic processes play counterpart roles that weaken the upper tropospheric warming. The warming center is most significant in spring. In contrast to other seasons, warming in spring primarily results from the adiabatic process, rather than the convection process. Although different in specific values, all three reanalysis datasets show a similar contribution ratio of each physical process.
Aurora ripples - a visual ionospheric emissions when auroral plasma sweeping through atmosphere
Authors: Li Bin
Published: March 2024

Based on the multi-scale statistical observations from antarctic Zhongshan station, a rippling aurora-like optical phenomena was observed near the poleward boundary of the aurora. The lack of red emission and extremely small scale indicated the aurora ripple is not likely been the result of the electron or ion perception along the magnetic field line. Through the statistical results of appearance location, fine scale structures and the consistence to the theoretical predication, the Aurora ripple is believed to be mainly caused by the plasma gradient drift instability around aurora. Dreyer et al described this phenomena as Fragmented aurora-like emissions in 2019, considering the patterns of emergence and progression associated with this phenomenon, we suggest to name it as "Aurora ripples". This designation is inspired by the visual resemblance of the phenomenon to rippless formed when a paddle moves through a lake, signifying the interaction of auroral plasma with the atmosphere.
Atmospheric isoprene measurements reveal larger-than-expected Southern Ocean emissions
Authors: Harris Neil R.P. , Ferracci Valerio , Weber James , Bolas Conor , Robinson Andrew , Tummon Fiona , Rodríguez-Ros Pablo , Cortés-Greus Pau , Baccarini Andrea , Jones Roderick L , Galí Martí , Simó Rafel , Schmale Julia
Published: March 2024

Isoprene is a key trace component of the atmosphere emitted by vegetation and other organisms. It is highly reactive and can impact atmospheric composition and climate by affecting the greenhouse gases ozone and methane and secondary organic aerosol formation. Marine fluxes are poorly constrained due to the paucity of long-term measurements; this in turn limits our understanding of isoprene cycling in the ocean. Here we present the analysis of isoprene concentrations in the atmosphere measured across the Southern Ocean over 4 months in the summertime. Some of the highest concentrations (> 500 ppt) originated from the marginal ice zone (MIZ) in the Ross and Amundsen seas, indicating the MIZ is a significant source of isoprene at high latitudes. Using the global chemistry-climate model UKESM1 we show that current estimates of sea-to-air isoprene fluxes underestimate observed isoprene by a factor >20. A daytime source of isoprene is required to reconcile models with observations. The model presented here suggests such an increase in isoprene emissions would lead to >8% decrease in the hydroxyl radical in regions of the Southern Ocean, with implications for our understanding of atmospheric oxidation and composition in remote environments, often used as proxies for the pre-industrial atmosphere.
Estimation of Reservoir Evaporation Water Loss in Inland China over the Past 30 Years
Authors: Zhu Yinuo , Ye Aizhong
Published: March 2024

Reservoirs have made significant contributions to human access and management of surface water resources, as well as to the production of clean energy, thus playing a vital role in alleviating the water crisis and decarbonizing energy systems through hydropower generation. The rapid growth in reservoir construction has led to an increase in the surface water area, consequently escalating evaporative water losses. As a crucial component of water cycle, most estimation methods for evapotranspiration focus on the land surface, with a relatively rough estimate of the significant evaporation loss from open surface water. Meanwhile, limited by the availability of reservoir geographic information and monthly area series data, there is still a lack of comprehensive and accurate estimation of reservoir evaporation losses. As the country with the largest number of dams in the world, it is necessary to accurately estimate China's surface water evaporation losses associated with its prosperous and developing dam construction. Here, we used the China Reservoir Dataset and LandSAT based Global Surface Water Dataset to reconstruct the monthly area series of 4874 reservoirs in China from 1984 to 2020, and further considering the heat storage of water bodies, the monthly evaporation losses of these reservoirs from 1988 to 2018 were estimated. The results indicate that the average annual evaporation volume of these 4874 reservoirs is 18.55 × 109 m3, equivalent to 31% of the total domestic water consumption of China (in 2021). During the research period, the evaporation rate shows a significant growth trend (p < 0.05, 0.15km3/year), attributed to the upward trend in evaporation rate (p < 0.05, 0.0046 mm/d/year) and total reservoir area (p < 0.05). The differences in economic development level and reservoir size result in significant spatial heterogeneity in the evaporation loss trend in different regions. The results can serve as a useful reference for water resources management and sustainable utilization.
Back-Propagating Rupture: Nature, Excitation, and Applications
Authors: Ding Xiaotian , Xu Shiqing , Fukuyama Eiichi , Yamashita Futoshi
Published: March 2024

In recent years, an intriguing feature of back-propagating rupture (BPR) has been reported during some earthquakes (Ide et al., 2011; Houston et al., 2011; Hicks et al., 2020; Okuwaki et al., 2021; Vallée et al., 2023). The occurrence of BPR challenges the classical interpretation of rupture propagation as a “forward” problem, while remaining less understood by the earthquake science community. Here, using fracture mechanics, we first argue that BPR is nothing but an intrinsic component of rupture propagation; however, its observability is usually masked by the superposition effect of interfering waves behind the primary, forward-propagating rupture front. We then suggest that perturbation to an otherwise smooth rupture process can break the superposition effect and hence can make BPR observable. To test our idea, we report results of mode-II rupture propagation from both numerical simulations and laboratory observations. By introducing a variety of perturbations (lateral variation in bulk or interfacial properties along the fault, singular stress drop, coalescence of two rupture fronts, etc.) during rupture propagation, we show that prominent phases of BPR indeed can be successfully excited. We further classify BPR into two modes: higher-order rupture or interface wave, depending on whether the already-ruptured fault is quickly healed and whether additional stress drop can be produced. Lastly, we propose several application potentials for BPR, such as constraining the velocity structure of fault zones, probing the mechanical state of faults, and studying the stability of perturbed slip along a homogeneous or bimaterial interface. Our study refines the understanding of the nature and complexity of rupture process, and can help improve the assessment of earthquake hazards.
Organic Pollutants and Chemicals of Emerging Concern at the atmospheric background stations of the German Environment Agency Air Monitoring Network
Authors: Rüdiger Julian , Bachmeier Franziska , Couret Cedric , Elsasser Michael , Hellack Bryan
Published: March 2024

Within the framework of multiple international conventions, Germany like other state parties is committed to monitor the air quality in the atmospheric background. Therefore, atmospheric measurements are realized by the German Environment Agency (Umweltbundesamt - UBA) with its network of 7 remote measurement stations throughout the rural background of Germany. These stations are operated by personnel and contribute data on pollutant deposition and transboundary long-range transport to the following monitoring programs: Global Atmosphere Watch (GAW), European Monitoring and Evaluation Program (EMEP), Convention on the Protection of the Marine Environment of the Baltic Sea Area (HELCOM), Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and as well as to the EU commission within the directive on ambient air quality and cleaner air for Europe (2008/50/EC).Some pollutants are measured continuously since the late 1960s, while other pollutants especially metals and semi-metals are monitored since the early 1990s. Organic pollutants such as PAHs and POPs are regularly monitored as well starting in the mid-1990s in precipitation and since the mid-2000s also in air and the aerosol phase. Therefore, the UBA air monitoring network contributes to the supervision of the Stockholm convention and the respective EU Regulation (2019/1021) on persistent organic pollutants.Recently further chemicals of emerging concern were included to the list of substances that are measured at the UBA air monitoring stations. Within a three-year project period, fluorinated organics such as per- and polyfluorinated substances (PFAS) and a range of current used pesticides (CUP) will be measured for the next two years in precipitation and air. This work presents the history of PAH and POP measurements at the UBA air monitoring network and the novel compounds of interest with the applied techniques for their detection and monitoring over the coming years.