bluuebunny/crossref_metadata_2025 huggingface dataset:
Time-lapse Acousto-Mechanical Response to Moisture-Induced Reduction of Fracture Stiffness in Granite
Authors: Wu Rui , Selvadurai Paul , Li Ying , Leith Kerry , Lei Qinghua , Loew Simon
Published: March 2024

Water infiltration into crustal rocks, particularly through fractures, significantly impacts seismic wave propagation and the characterization of fracture systems. Our study (Wu et al, 2023a) investigates the acousto-mechanical behavior of fractured granite experiencing gradual water infiltration over 12 days. We reveal an order of magnitude difference in wave amplitudes when compared to intact granite, with a correlation between wave amplitudes and the movement of the wetting front. The laboratory experiments show that fracture stiffness decreases exponentially as the wetting front advances, indicating moisture-induced matrix expansion (Wu et al, 2023b) around the fracture leads to increased asperity mismatch and reduced stiffness. By back-calculating the fracture stiffness and capturing the effects of water infiltration on seismic attenuation through a numerical model, this research illuminates how elastic waves propagate across fractures undergoing moisture-induced expansion, a crucial aspect of fracture characterization and understanding of the near-surface environment's response to hydrological changes. Our research sheds light on an important question in fracture characterization: how elastic waves propagate across a fracture undergoing moisture-induced expansion.Publications related to this research:Wu, R., Selvadurai, P. A., Li, Y., Leith, K., Lei, Q., & Loew, S. (2023a). Laboratory acousto-mechanical study into moisture-induced reduction of fracture stiffness in granite. Geophysical Research Letters, 50, e2023GL105725. https://doi.org/10.1029/2023GL105725Wu, R., Selvadurai, P. A., Li, Y., Sun, Y., Leith, K., & Loew, S. (2023b). Laboratory acousto-mechanical study into moisture-induced changes of elastic properties in intact granite. International Journal of Rock Mechanics and Mining Sciences, 170, 105511. https://doi.org/10.1016/j.ijrmms.2023.1055
The interprovincial moisture recycling in China and its tele-connected effects on socio-economy
Authors: sang shan , Li Yan
Published: March 2024

Freshwater change is a crucial component of the planetary boundary. It has exceeded the safe operating space due to intensified human activities, highlighting the urgency of rationalizing the use and effective management of water resource. The moisture recycling is the process by which water enters the atmosphere through evaporation and transpiration, travels with prevailing winds, and eventually falls as precipitation. It’s pivotal for transboundary water resource management, ecological protection and climate change adaptation. To analyze the spatial pattern of freshwater provisioning service flows through moisture recycling in each Chinese province, we used a moisture trajectory dataset from the UTrack model. The analysis reveals that the overall moisture flow within China is oriented towards the northeast, at an angle of 27 degrees north of east. Moisture in the northwestern, southwestern, and southern provinces flows eastward to generate precipitation, influenced by the westerlies. While in the eastern provinces, most of the moisture moves northwestward due to the influence of the southeast monsoon. Combining the socio-economic statistic data, we assessed freshwater provisioning service value of moisture in each province. Results indicate that Xizang has the most precipitation and surface water generated by moisture (200 km3), followed by Sichuan (122 km3) and Yunnan (95 km3). Regarding economic production, the impact of moisture on Gross Domestic Product (GDP) is most significant in Sichuan (2312 billion RMB), Hubei (1976 billion RMB), and Henan (1669 billion RMB). Western regions of China have made significant contributions to the surface water resources and economic development of the eastern regions through moisture recycling. The difference of the moisture contributions in each province highlights the intricate dynamics of moisture flow and its significant role in regional resource allocation and sustainable development. The results can provide innovative insights and practical references to guide water resource management endeavors, especially in transboundary water management, thereby contributing to mitigating freshwater change risks.
Sustainable Planning of Water and Land Resources in the Munneru River Basin, India
Authors: Buri Eswar Sai , Keesara Venkata Reddy , Kotapati Narayanaswamy Loukika
Published: March 2024

Water, a vital resource, plays a crucial role in supporting human health, ensuring food security, enabling energy production, and sustaining ecosystem services. However, water deficit is the main concern for developing countries caused by a number of factors including finite water supplies, increase in population, and climate change. A sustainable approach to manage the water resources is the optimal distribution of available resources, which recognizes the complex relationships between water systems and the effects they have on the environment, society and economy. In this study, the optimal allocation of land and water resources is carried out across five different sectors such as domestic, agriculture, livestock, industrial, and ecological in an annual time step. Munneru basin is selected as a study area which comes under lower region of the Krishna River Basin, India. Soil and Water Assessment Tool (SWAT) is used to calculate the water availability. Furthermore, for each administrative unit within the basin, the irrigation water requirements for crops are calculated using the CROPWAT tool. Study incorporates objective functions that take into account both social and economic factors. The multi-objective optimisation function maximizes the usage of water and land resources and optimize benefits from the agricultural sector. To achieve these goals, the Non-dominated Sorted Genetic Algorithm (NSGA-II) is used. Additionally, multi-criteria decision-making technique, such as Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is used to identify better solutions among the Pareto optimal solutions generated by the NSGA-II. Through the application of advanced optimisation algorithms and decision-making techniques, this study aims to contribute valuable insights to the field of water resource management in India. As this approach represents a crucial tool for sustainable development at the basin level, it provides a solid foundation for further extension to other basins across the globe. Furthermore, this work offers the potential for future research into the impacts of climate change and land use/land cover changes on water allocation over various timeframes, without compromising benefits from agriculture sector.
Detection and Attribution of the Weakening of Global Angular Momentum
Authors: Satpathy Susmit Subhransu , Franzke Christian L.E
Published: March 2024

The slowing down of the circulation in a warming climate due to anthropogenic forcings is still not understood. How internal variability and anthropogenic forced response in climate models influence the weakening of global angular momentum is still unclear. Here in this study, we utilise a 100-member ensemble simulation (CESM2-LENS) to detect and attribute the causes of the slowing down of atmospheric circulation. We observe a progressive decrease in angular momentum, projected to continue until 2100. The rate of weakening is observed to accelerate within the 1980~2020 period closely resembling the Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO) shift, with the entering of the positive phase of AMO and the negative phase of the PDO during the end of the 20th Century. Using, multivariate linear regression analysis, we provide the combined role of AMO, PDO, and GMST (a proxy for climate change signal) in influencing the angular momentum changes during the 20th and 21st centuries.Further, we use a statistical-based approach applied to the ensemble simulations to extract the indirect response (internal variability) and provide the linkage of the AMO and PDO shift in contributing to the weakening rate. We annotate that the shift in the AMO and PDO phases in the mid-1990s weakened the upper-level westerlies over the Northern Atlantic Pacific region and accelerated the weakening of the Hadley Cell circulation. This was due to internal variability contributing to the global angular momentum balance change. Our results elucidate the potential role of the climate system's internal variability and anthropogenic forcings in modulating the distribution of the global angular momentum.

Keywords: Angular momentum; Atmospheric Circulation; Anthropogenic Forced Response; Atlantic Multidecadal Oscillation (AMO); Pacific Decadal Oscillation (PDO); Hadley Cell; Atlantic-Pacific walker cell
Complexity of nutrient enrichment on subarctic peatland soil CO2 and CH4 production 
Authors: Byun Eunji , Rezanezhad Fereidoun , Slowinski Stephanie , Lam Christina , Saraswati Saraswati , Wright Stephanie , Quinton William L. , Webster Kara , Van Cappellen Philippe
Published: March 2024

Wildfires are increasing across northern high latitudes. Besides the immediate carbon pool losses from directly disturbed areas, recent studies have reported high porewater nitrogen (N) and phosphorus (P) concentrations in burned areas and downstream waters for a few months to several years after fire occurrence. Increasing nutrient deposition and soil fertilizer use have been widely investigated for water quality and carbon loss in agricultural soils, but not for remote subarctic peatlands. In this study, we sampled soil cores (0-25 cm) from a bog and a fen peatland in the Scotty Creek watershed in the Northwest Territories and conducted an incubation experiment for the effects of added nutrients in porewater. Aliquots of the peatlands were divided into separate containers and artificial porewater was added, either amended with dissolved inorganic N (NH4 + NO3), P (PO4), both N and P, or unamended. The production rates of gaseous CO2, CH4 and N2O were measured at 1, 5, 15, and 25°C. We further analyzed the initial and final soil physical properties, porewater chemistry, and microbial biomass C:N:P ratios. The fen incubations yielded overall greater CO2 and CH4 production rates than the bog incubations, which we attributed to differences in soil properties and initial microbial biomass. The N addition to the bog samples increased CO2 production, while the P addition to the fen samples increased CO2 production. The addition of both N and P reduced CO2 production but elevated that of CH4 for both peatland soils. After a month, the pore water C, N, and P stochiometric ratios approached the initial soil microbial biomass ratios, suggesting microbial nutrient recycling in an inherently nutrient-poor soil environment. These preliminary results imply a complex response of carbon turnover in peatland soils to nutrient enrichment.
Iron Sulfide Scale Characterization: Insights from Spectral Induced Polarization Method
Authors: Kirmizakis Panagiotis , Chen Tao , Aljeaban Norah , El-Husseiny Ammar , Mahmoud Mohamed , Soupios Pantelis
Published: March 2024

This study aims to explore the use and effectiveness of the spectral induced polarization (SIP) method for identifying and characterizing iron sulfide scales in oil and gas wells. Laboratory experiments using scale-amended columns aimed to confirm the SIP method's capability to differentiate between iron sulfide scales and other naturally occurring minerals and better understand scale formation. The polarization of different iron sulfide scales was measured in response to an applied electrical field of 0.01-10,000 Hz frequency range, with polarization being dependent on the material's frequency-dependent response to the field. The scale types analyzed in this study mainly consist of iron sulfides such as pyrrhotite, troilite, and pyrite, as well as iron oxides such as goethite and lepidocrocite. To ensure consistency and eliminate any effects of grain heterogeneity, the samples were ground and sieved to a particle size between 425 and 600 μm. Each sample was tested in acrylic columns modified with Ag-AgCl current and potential electrodes. The findings of this study demonstrate that the SIP responses, such as phase shift, impedance, real and imaginary conductivity, and calculated chargeability, are highly sensitive in distinguishing various scale types, including those with minor composition differences. X-ray diffraction and X-ray fluorescence analysis validated the differentiation of the samples' mineral and elemental composition. Although phase and imaginary conductivity responses exhibit similar trends, phase clarified differentiation between the measured samples. The recorded signals present a clear trend dependent on the mineralogical composition and the iron content. Iron sulfide scales have a characteristic electrical response that differs from other natural iron-rich materials tested. This difference in electrical response is due to the unique electronic structure of iron sulfide minerals, which allows them to act as charge carriers. As a result, iron sulfide scales exhibit a high polarization response, which can be detected using the SIP method. SIP is a powerful geophysical technique that can provide valuable information about subsurface properties in micro-scale and fluid content. Unfortunately, due to poor exposure, SIP has not been widely adopted in the Oil & Gas industries. The SIP method offers several advantages over traditional methods of scale identification. With further research and development, the SIP method has the potential to become a standard tool for scale management in the oil and gas industry.
AMADEE-24: pushing the limits of Mars missions
Authors: Lopez Llobet Laia , Mandal Soumyajit
Published: March 2024

Planetary analog missions are the mechanism to prepare human space exploration for upcoming missions to other planetary bodies. These kinds of human and robotic surface activities in terrestrial analogs are essential for determining the requirements and impacts of long term space missions. The AMADEE program, managed by the Austrian Space Forum (OeWF), is one of the largest Mars analog simulations. In 2024, the 4-week AMADEE-24 Mars analog will be hosted by the Armenian Space Agency. Several experiments will be performed in order to study the geological environment and physical and psychological conditions in which the astronauts will work. All of these are crucial to understanding the scope and limitations of the future human planetary missions. The aim of this presentation is to give an overview of the flight planning activities and experiments’ coordination pre-, in-, and post- mission phases. We will describe the mission architecture, team composition, scientific aims, roles and responsibilities of the various teams involved in the mission.
Characterization of snow mechanical properties using laser ultrasound: Role of snow crystal type
Authors: McCaslin James , Mikesell Thomas , Marshall Hans-Peter , Courville Zoe
Published: March 2024

Quantifying the mechanical properties of snow is crucial for various applications, including the assessment of slope stability, vehicle mobility on snow-covered terrain, and the understanding of snowpack evolution. To build our understanding of snowpack evolution, we utilize a novel non-contacting laser ultrasound system (LUS). This system collects ultrasonic wavefield data from tens to hundreds of kilohertz in a controlled cold lab environment, allowing us to interpret acoustic measurements and measure mechanical properties on a microscale and upscale this to the field scale.  We investigated the relationship between P-wave velocity changes and snow properties such as density, snow crystal type, and metamorphism through sintering. We controlled the density of the snow samples by adjusting the volume while maintaining the same mass. We controlled the microstructure by manipulating the supersaturation and temperature (controlling air and water temperatures within an artificial snow maker) within a cold lab to make artificial snow of a specific crystal type (i.e., Dendritic, plate, column, and needle snow crystals). Homogeneous snow samples, each composed of their own single crystal type, were created and compacted to a density of 250 kilograms per cubic meter. Over a period of 72 hours, we measured acoustic wave propagation through  these artificial snow samples to periodically observe changes in waves peed during metamorphism. This allowed us to monitor changes in mechanical properties as sintering occurred, for different snow crystal types. We also measured snow microstructure and micromechanical properties with destructive techniques, using the SnowMicroPen and MicroCT. Finally, we examined the relationship between velocity changes and snow crystal types, specifically in terms of sintering time. Our findings suggest that the crystal type, as influenced by time under isothermal temperature conditions, affects the observed bulk mechanical properties and their rate of change.  Observations of ultrasonic wavefields show that snow strengthened by a factor of 1 to 2 within 72 hours, depending on the snow crystal type. 
Ground beetles trophic interactions alter available nitrogen in forest soils
Authors: Lienau Janey , Duguid Marlyse C. , Schmitz Oswald J.
Published: March 2024

The dominant paradigm is that nitrogen cycles from plants to soil organic matter, being released in mineral form in the soil after organic matter is decomposed by microbes to be taken up again by plants. It is generally held that the process of decomposition is the rate-limiting step in the cycle. Ground dwelling macroinvertebrates may play a large role in ecosystem function by mediating microbe decomposition via predation and could be key links between plant litter and nitrogen availability in soil nutrient cycles. Ground beetles (Carabidae) are an abundant family of soil invertebrates that prey on groups of decomposing invertebrates. The goal of this study was to develop how predation from ground beetles contributes to nitrogen cycling as forests age. We hypothesized that ground beetles in young and old forests would indirectly impact available nitrogen. Our approach to addressing predator impacts on nitrogen cycling in forest soils was an experiment in young and old forest stands at Yale-Myers Forest in the northeastern United States using mesocosm cages stocked with predatory and detritivore ground beetles to create a trophic cascade over 68-days. Both forest sites had five blocks of three clustered treatments (n = 30). Treatments consisted of a control, detritivore, and predator and we took soil cores in each cage to assess available nitrogen. We used standard mesocosm cages that were designed for research on arthropod trophic interactions in ecosystems 1 m2, 0.8 m tall cylindrical mesocosms constructed with a scaffolding covered with fine mesh aluminum stocked with live beetles. We conducted a series of linear mixed-effect models in RSudio from the nlme package and lme() function in R Studio to predict the delta nitrogen mineralization rate by treatment in both young and old forests separately. We used ground beetle treatment as a fixed effect and block as a random effect to account for variation in microsite differences. Here we show differences in available nitrogen between forest types (P-value = 0.03). Our hypothesis that predators would impact available nitrogen was supported in young forests. Net nitrogen mineralization (P-value = 0.007) was consistently higher in the predator treatments compared to the control. In conclusion, this study suggests predator top-down control may be important for soil nitrogen availability in temperate forest soil via mediating microbe decomposition. Macroinvertebrates and their food web interactions in the soil should be further investigated and included in soil biogeochemical models.
From hydraulic root architecture models to efficient macroscopic sink terms 
Authors: Leitner Daniel , Schnepf Andrea , Vanderborght Jan
Published: March 2024

Root water uptake strongly affects soil water balance and plant development. It can be described by mechanistic models of soil-root hydraulics based on soil water content, soil and root hydraulic properties, and the dynamic development of the root architecture. Recently, novel upscaling methods have emerged (Vanderborght et al. 2023, 2021), which enable the application of detailed mechanistic models on a larger scale, particularly for land surface and crop models, by using mathematical upscaling.In this study, we explore the underlying assumptions and the mathematical fundamentals of the upscaling approach. Our analysis rigorously investigates the errors introduced in each step during the transition from fine-scale mechanistic models, which considers the nonlinear perirhizal resistance around each root, to more macroscopic representations. Upscaling steps simplify the representation of the root architecture, the perirhizal geometry, and the soil spatial dimension and thus introduces errors compared to the full complex 3D simulations. In order to investigate the extent of these errors, we perform simulation case studies: spring barley as a representative non-row crop and maize as a representative row crop, and using three different soils.We show that the accuracy of the upscaled modeling approach strongly differs, depending on  root architecture and soil type. Furthermore, we identify the individual steps and assumptions that lead to the most important losses in accuracy. An analysis of the trade off between model complexity and accuracy provides valuable guidance for selecting the most suitable approach for specific applications. References Vanderborght, J., Couvreur, V., Meunier, F., Schnepf, A., Vereecken, H., Bouda, M., and Javaux, M. (2021). From hydraulic root architecture models to macroscopic representations of root hydraulics in soil water flow and land surface models. Hydrology and Earth System Sciences, 25(9):4835–4860.Vanderborght, J., Leitner, D., Schnepf, A., Couvreur, V., Vereecken, H., and Javaux, M. (2023). Combining root and soil hydraulics in macroscopic representations of root water uptake. Vadose Zone Journal, e20273.
Evaluation of uncertainties in flash flood hazard mapping caused by selection of topographic indicators: A case study in the Yarlung Zangbo River basin, China
Authors: Tian jiayu , Wang zhonggen
Published: March 2024

Rainstorm-induced flash flooding is a serious and recurring natural hazard in the Tibetan Plateau region. Flash flood hazard mapping is an important tool for identifying flood hazard areas. However, results indicated that the selection of indicators representing topography, especially river characteristics may bring the largest uncertainties in Flash flood hazard mapping. In this study, we will evaluate the uncertainties that are caused by indicators of river characteristics by selecting three usually used indicators representing river characteristics for generating three corresponding flash flood hazard maps of the Yarlung Zangbo River basin (YZRB). The three indicators are a) drainage density only; b) distance to a river only; and c) drainage density and distance to a river. Comparing the results with historical flash flood sites and validating them using the single-parameter sensitivity approach, it was found that using both drainage density and distance to the river gives a more accurate flash flood hazard assessment in YZRB. Our findings clarified the uncertainties caused by the selection of river characteristics indicators and filled the gap in the application of flash flood hazard mapping in YZRB. Based on the above findings, we further mapped flash flood hazard regions and the corresponding zoning and it will provide a reference for mitigating potential flash flood events in the YZRB. It is shown that the highest hazard zones were in the YZRB’s middle reaches, particularly in Sangzhuzi district, Qushui county, Gongga county, and their nearby areas.
Regional Variation in Precipitation characteristics observed by space-borne Precipitation Radar 
Authors: Kumar Amit , Srivastava Atul Kumar , Srivastava Manoj Kumar
Published: March 2024

Dual-frequency precipitation radar (DPR) placed on the Global Precipitation Measurement (GPM) satellite provides a three-dimensional distribution of precipitation between 650N- 650S. The availability of precipitation parameters at the spatial resolution of 0.10*0.10 and temporal resolution of 30 minutes can be used to investigate the microphysical process responsible for the precipitation. We analyzed the GPM-DPR level 2 V07 observed data collected over the Southern region of India and the surrounding Oceanic region to understand the precipitation characteristics in the pre-monsoon and monsoon seasons. India Meteorological Department (IMD) gridded rainfall data at the resolution 0.250 is used to validate GPM-DPR data over the landmass region. There is significant variation in the temporal and spatial distribution of reflectivity (Z), rain rate (R), and DSD parameters such as mass-weighted mean diameter (Dm) and normalized intercept parameter (Nw). In the monsoon season, higher precipitation frequency provides considerable accumulated precipitation throughout India. However, the frequency of intense rainfall is higher in the pre-monsoon season than in the monsoon season, as most of rain events occur over the Ocean instead of land. The mean of R, Z, and Dm is small, and a large Nw value is observed in the monsoon season, as stratiform clouds (more than 68%) contribution in monsoon precipitation is more than convective clouds. The distribution of average Dm, Z, and R in pre-monsoon indicates the presence of bigger rain droplets, possibly due to the enhancement in the collision-coalescence process and slow-down of the break-up process. The share of convective clouds in overall precipitation on the land surface increased in the pre-monsoon season. The fluctuation in Dm not only occurs with topography, season, and R, but also with the concentration of heavy ice precipitation particles above the bright band and microphysical process. Simultaneously, in both pre-monsoon and monsoon seasons, a modest relationship was detected between the incidence of heavy precipitation and maximum echo top reflectivity.
The electrical activity of a thunderstorm under high dust circumstances over Beijing metropolis region
Authors: Sun Chunfa , Qie Xiushu , Liu Dongxia , Xian Xiao
Published: March 2024

A rare dust-thunderstorm swept the Beijing area on April 15, 2021, generating frequent lightning, dirt precipitation, and gusting. Based on comprehensive data from satellite retrieval, in-situ observation, weather radar, and reanalysis data, this study investigated the effect mechanism of dust on electrical activity of this dust-thunderstorm. The results showed that dust from Mongolia were involved in the development and intensification of the thunderstorm. During the evolution of the thunderstorm, the ground electrical field changed positively with the highest value of 9 kV. PM2.5 and PM10 increased rapidly with the highest values of 1500 ug/m3 and 250 ug/m3 under the influence of dust. The positive cloud-to-ground (+CG) lightning accounted for a high percentage with an average ratio of more than 50%. The dust acting as effective ice nuclei (IN) and cloud condensation nuclei (CCN) invading the thunderstorm were likely to increase the content of ice-phase particles, resulting in a high proportion of +CG lightning. Considering the mechanism of CCN and IN on electrification, this study conducted further sensitivity simulation experiments on dust effect on dynamic-microphysics-electrification by the WRF-ELEC model, which coupled with a heterogeneous nucleation scheme for IN associated with aerosol concentration. The results indicate that the increases of dust influence the concentration and the size of different hydrometeor particles within this dust-thunderstorm, leading to changes in the charge structure and a significant increase in the proportion of +CG lightning.
Assessing Fine Root Production in Terrestrial Forests: A Comparative Analysis of AI and Human Annotation Using Minirhizotron Images
Authors: Carter Imogen , Handy Grace , Arnaud Marie , Mackenzie Rob , Denny Gael , Smith Abraham , Esquivel-Muelbert Adriane
Published: March 2024

Fine roots are a major source of the stabilised carbon in soils. However, the response of fine root production to an increase in atmospheric CO2 and its impact on carbon dynamics in terrestrial forests remain poorly understood. Minirhizotrons can help to quantify fine root production and associated carbon dynamics in long-term, in-situ experiments such as Free Air CO2 Enrichment experiments. Yet, using minirhizotrons requires the manual annotation of thousands of images. Artificial Intelligence (AI) technology for image processing is fast developing and has proven to be successful in simple systems, such as agronomous crops. Here, we quantified how AI (RootPainter) annotation compares with humans, and determined the implications in terms of root production and carbon dynamics in a mature deciduous forest (BIFOR-FACE). Firstly, we quantified the variation in outputs of 30 annotated minirhizotron images using AI and human analysts of varying levels of expertise, comparing them to a gold standard established through expert consensus. We find that root annotation varied substantially among humans, with novices and AI over-annotating root length by 244% and 206% respectively, compared to our gold standard. Secondly, we quantified root length for five minirhizotron tubes in March and June (n = 1060 images) using AI and then a trained human analyst. AI over-estimated root length by more than an order of magnitude compared to a trained human user, and there was a poor linear relationship between annotated images with  AI and humans (r² < 0.22 for both months). This over-annotation by AI resulted in inaccurate quantification of root production and mortality, and thus erroneous carbon budget.
Preliminary Investigation of Volcanic Succession and Mineralogy of the Southern part of Mount Ağrı, Eastern Anatolia, Turkey 
Authors: Madak Zeynep , Varol Elif , Dogan Kulahci Gullu Deniz
Published: March 2024

Preliminary Investigation of Volcanic Succession and Mineralogy of the Southern part of Mount Ağrı, Eastern Anatolia, Turkey

 

Zeynep Madak1*, Elif Varol1, G. Deniz Doğan-Külahcı1
 

1  Hacettepe University, Department of Geological Engineering, 06800, Ankara, Türkiye
 

 

Mount Ağrı is a significant stratovolcano located in Eastern Anatolia, Turkey, characterized by its steep conical shape and unique ice-capped structure. It is generally considered part of the Alpine-Himalayan orogenic belt and developed in the Quaternary, with its last known eruption occurring in 1840.
 
The volcanic succession in the southern part of Mount Ağrı begins with basaltic volcanic lava flows. These lower lava flow units exhibit a hypocrystalline porphyritic texture and contain a mineral assemblage of plagioclase + pyroxene ± olivine + oxide. These lava flows are overlain by a series of Plinian pumice-fall deposits of varying thicknesses of layers, which include ash-size volcanic material, different sizes of normally graded pumices, and inversely graded lithic clasts. Predominantly slaty fabric is observed in the pumices, with the thickness of pyroclastic fall deposits ranging up to 20 m and the color of the sequences varying between beige and white.
 
Finally, younger lava flows overlie these pyroclastic sequences. These younger lavas generally exhibit a hypocrystalline porphyritic texture, although an aphanitic texture has also been observed. The upper lava flow units display a mineral assemblage of pyroxene + plagioclase + oxide. The ongoing geochemical analyses will unveil the processes influencing the formation of these volcanic rocks and help determine the origin of the magma.
 

 

Key words: Mount Ağrı, Eastern Anatolia,  plinian fall deposits, lava flow, mineralogy
The Impact of Wildfires on Atmospheric Nitrogen Deposition in the United States: A Multiple Linear Regression-based Analysis
Authors: Mu Jiangshan , Zhang Yingnan , Tao Chenliang , Liu Zhou , Zhao Yu , Zhang Lei , Zhang Yuqiang , Xue Likun
Published: March 2024

Nitrogen deposition can exert a significant impact on global ecosystems. The increased occurrence of natural factors such as wildfires are becoming more important in atmospheric deposition especially with the continued decreases of the anthropogenic emissions in developed countries. In this study, we investigate the mechanisms by which the increasingly frequent wildfires affect nitrogen deposition in the United States using comprehensive datasets and multiple linear regression (MLR) methods. We found a downward trend in nitrogen deposition in the U.S. (-0.09 kgN ha yr-1), mainly due to the decreases in oxidative nitrogen deposition (-0.1 kgN ha yr-1). In contrast, reduced nitrogen deposition showed a slight increase (0.02 kgN ha yr-1). Our preliminary results show that wildfires contributed ~10% to the U.S. domestic deposition overall, but the magnitudes and signs of impact vary geographically, depending on the frequency and intensity of wildfires and the dominant deposition types. On average across the U.S., wildfires predominantly negatively contribute to wet deposition, while their contributions to dry deposition is smaller or slightly positive. Specifically, wildfires enhance dry deposition in the western U.S. while inhibiting wet deposition in the southeastern U.S. Wildfires exert a suppressive effect on both oxidized and reduced forms of nitrogen deposition in the southeastern U.S. Our study highlights the significant influence of wildfires on nitrogen deposition, underscoring the need to consider wildfire events in environmental management and policy-making.
Contextual detection of muons and neutrons as a way to self-referenced Cosmic Ray Neutron Sensing
Authors: Gazzola Enrico , Stevanato Luca , Biasuzzi Barbara , Lunardon Marcello , Morselli Luca , Gianessi Stefano , Zara Mario , Lorenzi Federica
Published: March 2024

As Cosmic Ray Neutron Sensing (CRNS) gains increasing importance in Hydrology and other fields related to measurement of water in various form (notably Soil Moisture, Snow Water Equivalent, Biomass Water Equivalent), its large-scale application risks to be hindered by the complex calibration of site-specific parameters. The success of CRNS comes from its ability to straightforwardly determine the amount of water content in soil and snow, overcoming limitations in scale representativity of more traditional technologies like point probes and satellites. A single, autonomous probe placed over the ground is in fact capable of delivering a real-time estimation of the Soil Moisture (SM) on a large scale (hectares) and in depth (tens of cm in soil, meters in snow).CRNS is based on the fact that neutrons strongly interact with hydrogen, of which water is rich, therefore providing a correlation between the number of neutrons backscattered by the soil and the water content. The neutrons source is provided by the interaction of cosmic radiations with the atmosphere. Advantageous as it is to use a naturally available source, it comes with the drawback of having a natural variability that needs to be account for, which is usually done by refferring to a public network of cosmic neutrons observatories (the Neutron Monitor DataBase, NMDB). A second critical hurdle is calibration, requiring the determination of a site-specific reference value for the neutrons count rate through a complex campaign of soil sampling and analysis.Finapp developed a patented detection technology characterized by the unique capability of contextually detecting muons, another kind of particle generated by cosmic rays. Since muons are not backscattered by the soil, their measurement is only related to the incoming flux. Years of measurements provide evidence of the correlation of local muons flux variations with the general trend of incoming neutrons as measured by NMDB stations.Not only this offers the possibility to monitor the incoming flux variations locally without the need to rely on an external entity, but it furthermore suggests that the expected reference neutrons rate on a given site should be proportional to the measured muons flux. Although additional parameters will still need to be included to account for Additional Hydrogen Pools in the soil, this approach can greatly simplify the calibration procedure.We will therefore present the state-of-the-art of the use of muons as a reference in CRNS and in particular early results of the novel muons-based calibration approach.
Implications for Non-Self Similar Energy and Moment Scaling of Small-to-Moderate Earthquakes Along the NAFZ: Source Displacement Spectra Derived from Coda Waves
Authors: Özkan Berkan , Eken Tuna , Gaebler Peter , Taymaz Tuncay
Published: March 2024

For decades, the seismological community has debated the scaling relationships of earthquake sources. The debate centers around whether the scaled energy (ER/M0) remains uniform across all magnitudes, indicating self-similarity, or if there is an increase in scaled energy with seismic moment, M0. To contribute to this discussion, we analyzed coda derived source displacement spectra of 303 local earthquakes that occurred in and around the segments of the North Anatolian Fault Zone (NAFZ) within the Sea of Marmara. Our database includes digital waveform recordings of the events that were occurred between 2018 and 2020 (2.5≤ ML ≤5.7 within a radius of 200 km) and were recorded at 49 seismic stations operated by the Kandilli Observatory and Earthquake Research Institute (KOERI) in the study area. We employed a joint inversion technique to optimize source-, path-, and site-specific factors simultaneously. This was achieved by comparing the observed coda envelope with its physically derived representative synthetic coda envelope based on Radiative Transfer Theory. Our inversion process, conducted across various frequency bands, enabled us to make reliable coda-based seismic moment (M0) and moment magnitude estimates (Mw-coda) consistent with local catalogue magnitudes. The variation of the scaled energy (ER/M0) calculated from the total seismic radiated energy (ER) using coda-derived source displacement spectra for each event tends to increase with seismic moment across most magnitude ranges. This indicates that the crustal earthquakes with Mw-coda 2.5 and Mw-coda 5.7 in this laterally heterogeneous region are likely to follow non-self-similarity. Our findings imply different rupture dynamics working for large earthquakes than small ones and relatively more efficient seismic energy radiation for larger earthquakes along the northwestern part of the NAFZ.
Shifts of Formation Regimes and Increases of Atmospheric Oxidation in North China Plain and Yangtze River Delta From 2016 to 2019
Authors: Wang Peng , Zhu Shengqiang , Zhang Hongliang
Published: March 2024

China is confronting severe ozone (O3) pollution although particulate matter reduced
significantly, causing damages to public health and ecological systems. Here we utilized the comprehensive methods of ground-level observations, satellite data, and source-oriented chemical transport model to interpret O3 variations throughout China from 2016 to 2019. A remarkably worsened trend of O3 levels has been found both by observation and simulation in these years. Our results showed that the remarkable O3 elevation was found in the North China Plain (NCP) and Yangtze River Delta (YRD) (maximum daily 8 hr average O3 ∼60 ppb) with an annual increasing rate of 10%. In addition, O3 formation regimes also changed in the NCP, where 4.9% grids shifted from VOC-limited to transition regimes and 9.6% grids shifted from transition to NOx-limited regimes. The elevation of MDA8 O3 was mainly attributed to the enhanced atmospheric oxidation capacity (AOC) in above regions. Particularly, the increasing rates of OH and HO2 radicals (major oxidants) in NCP and YRD reached ∼15% and ∼5%, respectively. The comprehensive study of long-term O3 changes, formation regimes, and AOC based on a multimethod approach should be considered when designing O3 control policies.
Effect of Maize Mucilage on Soil Nutrient Transport
Authors: Hosseini Bahareh , Cheraghi Meysam , Holz Maire , Remus Rainer , Pusch Valerie , Zarebanadkouki Mohsen
Published: March 2024

Soil water conditions crucially influence plant nutrient uptake, especially when dry conditions limit nutrient diffusion in soil. Recently Chia seed mucilage has been shown to enhance nutrient transport by augmenting soil water-holding capacity, reducing liquid phase tension, and increasing viscosity. However, the impact of plant mucilage on nutrient diffusion in different soils and moisture levels remains to be determined.
In this study, we assessed maize root-derived mucilage effects on calcium (Ca) diffusivity in soils with varying textures (sand, sandy loam, loam) and moisture levels (25, 15, 7.5%). 45Ca was used as a tracer for the diffusion of nutrients within soils. The soils were adjusted to the desired water contents using either distilled water or a solution of 60 mM 45CaCl2. Then, soil wetted with distilled water was packed into the first half part of the containers with a size of 5x1x0.3 cm, and the other half was packed with soils wetted with 45CaCl2. Over 65 days, digital autoradiography was employed to trace the diffusion of 45Ca within the soil. A 1D diffusion equation was employed to simulate the transport of Ca within the soil by inversely adjusting the diffusion coefficient of the soil. Our findings revealed that mucilage significantly influenced soil diffusivity, contingent on content, soil texture, and moisture levels. Higher mucilage concentration initially delayed 45Ca diffusivity, especially in finer textures probably due to the gel's viscosity. However, it prevented a significant drop in diffusion rate in drier conditions, resulting in higher 45Ca diffusivity compared to control soils.
In summary, maize mucilage improved the diffusivity of Ca in dry conditions by maintaining the continuity of the liquid phase.
GCM selection based on weather patterns for extreme heat: a case study over Belgium
Authors: Serras Fien , Vandelanotte Kobe , Borgers Ruben , Van Schaeybroeck Bert , Demuzere Matthias , Termonia Piet , van Lipzig Nicole
Published: March 2024

The process of selecting suitable time periods within the Coupled Model Intercomparison Project Phase 6 (CMIP6) for a specific region and warming level presents notable challenges, such as the incomplete representation of atmospheric dynamics and climate-change uncertainties. This study aims to develop a selection procedure for CMIP6 model periods using a methodology to address both the representation of atmospheric dynamics and the relevant changes in the climate variable of interest. In the first step, the representation of past atmospheric dynamics is evaluated to investigate the model quality. This is then used as a criterion to exclude underperforming models. The second step gives information on interesting model periods and indicates which model periods are relevant for selection.To eliminate models that did not adequately represent historical atmospheric dynamics, the Lamb Weather Type (LWT) classification was used to assess the representation of large-scale circulation patterns across 33 CMIP6 models and compare these with ERA5. This resulted in the exclusion of three CMIP6 models for the circulation regimes over Belgium. Furthermore, in order to account for the increased occurrence of weather patterns related to extreme heat, while also reducing the number of different weather types of the existing LWT classification, the classification was adapted to incorporate a temperature-dependent classification through the optimization of the clustering of weather types and the associated maximum temperatures. Additionally, a new index, the hot weather type index, was introduced and combined with a set of heat-related metrics to illustrate the selection methodology. The final period selection was made based on the combination of the ranks of the different metrics for each global warming level considered.The method developed in this study offers a framework for selecting periods within CMIP6 while considering both the uncertainties of the large-scale circulation patterns and changes in the climate-change signal. This framework holds potential to contribute to regional climate modelling and facilitate decisions related to the selection of model periods for dynamical downscaling of relevant climate projections.
Matlab Interface for Seismo‐Acoustic aRray Analysis (MISARA)
Authors: Minio Vittorio , Zuccarello Luciano , De Angelis Silvio , Di Grazia Giuseppe , Saccorotti Gilberto
Published: March 2024

Volcanic activity generates diverse seismic and acoustic signals that offer valuable insights into the underlying magmatic processes. Contemporary volcano monitoring relies on networks and arrays of seismic and acoustic sensors. The analysis of signals acquired by these instruments necessitates streamlined workflows and specialized software. The high sampling rates, typically exceeding 50 Hz, employed in recording seismic and acoustic waveforms by multi-station networks and dense arrays result in the swift accumulation of substantial data volumes, posing a formidable challenge in establishing efficient data analysis workflows for volcano surveillance.In this context, we introduce MISARA (Matlab Interface for Seismo-Acoustic aRray Analysis), an open-source MATLAB graphical user interface. MISARA is meticulously crafted to furnish a user-friendly workflow for analyzing seismo-acoustic data in volcanic settings. It incorporates efficient algorithmic implementations of established techniques for seismic and acoustic data analysis, with a focus on supporting the visualization, characterization, detection, and location of volcano seismo-acoustic signals. The intuitive and modular structure of MISARA facilitates swift, semi-automated data inspection and result interpretation, thereby minimizing user effort.Validation of MISARA involved testing it with seismo-acoustic data recorded at Etna Volcano (Italy) during 2010, 2011, and 2019. The tool is intended for educational and research purposes and is well-suited to aid routine data analysis at volcano observatories. Its open-source nature encourages collaborative development and adaptation, fostering advancements in volcano monitoring and contributing to the broader scientific community.