Geophysical Factors Research Articles

Green spaces and flood vulnerability in urbanising regions: a case study in the Philadelphia metropolitan area

ABSTRACT Flooding continues to be one of the most significant natural hazards, disproportionately impacting vulnerable populations in urbanising regions. This study aims to examine the relationship between green space density and flood vulnerability in the Philadelphia Metropolitan Area by integrating social and geophysical data. The research focuses on identifying areas where high flood vulnerability coincides with low green space availability, as these are critical regions for targeted intervention. Using social vulnerability indicators such as income, age, and housing characteristics, combined with geophysical factors like soil permeability and drainage density, the study assesses flood vulnerability across census block groups. Local Indicators of Spatial Association (LISA) and discriminant analysis were employed to detect spatial clusters with elevated flood risks and low green space density. Results reveal that these high-risk clusters are concentrated in densely urbanised areas such as Norristown, where lower-income and elderly populations are overrepresented. These findings reinforce broader environmental justice concerns, as socially vulnerable communities face compounded risks from both inadequate flood protection and limited access to green spaces. The study emphasises the need for integrated flood management, combining green infrastructure with structural interventions, to guide urban planners and policymakers in reducing flood risks and promoting environmental equity.

Modelling the interrelationships between potential risk factors and childhood Co-morbidity of Malaria, Anaemia, and stunting in children less than five years in Burundi

BackgroundAnaemia, malaria, and stunting remain health problems, especially in children younger than five years, and those conditions are linked to morbidity and mortality. The main objective was to assess the relationships between anaemia, malaria, and stunting. Also, the current study aimed to understand the complex interrelationships between explanatory factors, and their direct or indirect relationship with childhood malaria, anaemia, and stunting in Burundi. MethodsThe study used secondary data from the Demographic and Health Survey in Burundi (BDHS) conducted on the March 7, 2017, with a weighted sample size of 13611 children younger than five years. A multivariate structural equation model (SEM) was used to evaluate the interrelationships between dependent variables and their direct or indirect relationship with childhood malaria, anaemia, and stunting. SEMs diverge from other techniques, as they look at the effects on hypothesised relationships from both direct and indirect perspectives (Takele et al., 2023) [1]. The variables with statistical significance were set at a p-value <0.05. ResultsThe findings from this study indicated an association between anaemia, malaria, and stunting (p < 0.001). The environmental and household factors were statistically significant (p < 0.038 and p < 0.001 respectively) and positively impacted childhood malaria, anaemia, and stunting. The results also indicated that the household factors were statistically significant (p < 0.001) predictors of childhood malaria, anaemia, and stunting. Furthermore, the findings from this study revealed that geophysical factors have a positive significant (p < 0.001) impact on childhood malaria, anaemia, and stunting via the mediating of the household factors. Contrastingly, with the environmental factors as a mediator, we observe a negative significant (p < 0.001) impact on childhood malaria, anaemia, and stunting. Lastly, the results showed that demographic factors had a negative significant (p = 0.004) effect on childhood anaemia, malaria, and stunting via the mediating of household factors. ConclusionThe findings from this study revealed an association between malaria, anaemia, and stunting, which imply that these conditions could contribute to collaborative improvements in child well-being. In addition, child demographic, household, environmental, and geographic factors were direct and indirect important drivers of childhood malaria, anaemia, and stunting. Therefore, improving sanitation, access to clean water, nutrition practices, and health care, especially for children from rural areas, and uneducated mothers with poor backgrounds could help to control and eliminate stunting, anemia, and malaria in children younger than five years in Burundi.

Dome Craters on Ganymede and Callisto May Form by Topographic Relaxation of Pit Craters Aided by Remnant Impact Heat

AbstractThe icy Galilean satellites display impact crater morphologies that are rare in the Solar System. They deviate from the archetypal sequence of crater morphologies as a function of size found on rocky bodies and other icy satellites: they exhibit central pits in place of peaks, followed by central dome craters, anomalous dome craters, penepalimpsests, palimpsests, and multi‐ring structures. Understanding the origin of these features will provide insight into the geophysical factors that operate within the icy Galilean satellites. Pit craters above a size threshold feature domes. This trend, and the similarity in morphology between the two classes, suggest a genetic link between pit and dome craters. We propose that dome craters evolve from pit craters through topographic relaxation, facilitated by remnant heat from the impact. Our finite element simulations show that, for the specific crater sizes where we see domes on Ganymede and Callisto, domes form from pit craters within 10 Myr. Topographic relaxation eliminates the stresses induced by crater topography and restores a flat surface: ice flows downwards from the rim and upwards from the crater depression driven by gravity. When the starting topography is a pit crater, the heat left over from the impact is concentrated below the pit. Since warm ice flows more rapidly, the upward flow is enhanced beneath the pit, leading to the emergence of a dome. Given the timescales and the dependence on heat flux, this model could be used to constrain the thermal history and evolution of these moons.

Sea Surface Height Measurements Based on Multi-Antenna GNSS Buoys.

Sea level monitoring is an essential foundational project for studying global climate change and the rise in sea levels. Satellite radar altimeters, which can sometimes provide inaccurate sea surface height data near the coast, are affected by both the instrument itself and geophysical factors. Buoys equipped with GNSS receivers offer a relatively flexible deployment at sea, allowing for long-term, high-precision measurements of sea surface heights. When operating at sea, GNSS buoys undergo complex movements with multiple degrees of freedom. Attitude measurements are a crucial source of information for understanding the motion state of the buoy at sea, which is related to the buoy's stability and reliability during its development. In this study, we designed and deployed a four-antenna GNSS buoy with both position and attitude measurement capabilities near Jimiya Wharf in Qingdao, China, to conduct offshore sea surface monitoring activities. The GNSS data were processed using the Precise Point Positioning (PPK) method to obtain a time series of sea surface heights, and the accuracy was evaluated using synchronous observation data from a small sea surface height radar. The difference between the GNSS buoy and the full-time radar was calculated, resulting in a root-mean-square error (RMSE) of 1.15 cm. Concurrently, the attitude of the GNSS buoy was calculated using multi-antenna technology, and the vertical elevation of the GNSS buoy antenna was corrected using the obtained attitude data. The RMSE between the corrected GNSS buoy data and the high ground radar was 1.12 cm, indicating that the four-antenna GNSS buoy can not only acquire high-precision coastal sea level data but also achieve synchronous measurement of the buoy's attitude. Furthermore, the data accuracy was also improved after the sea level attitude correction.

GIS-Based Analytical Hierarchy Process Modelling and Mapping of Erosion Vulnerability in the Coastal Areas of Rivers State, Nigeria

The problem of coastal erosion in rivers State Nigeria is a significant issue that has far-reaching consequences for the environment and local communities. Despite the efforts of previous research there remains a lack of comprehensive understanding of the factors contributing to erosion vulnerability and their relative importance, hindering effective decision-making and management practices aimed at mitigating the effects of coastal erosion in Rivers State. Therefore, this study aimed at a GIS-based analytical hierarchy process modeling and mapping of coastal erosion vulnerability in Rivers State, Nigeria. The objectives are to establish and classify the geophysical factors according to the levels of coastal erosion risk, calculate the reliability index of the classified geophysical factors, determine the coastal vulnerable areas across Rivers State using analytical hierarchical process and to produce a coastal vulnerability index map defining the extent of erosion vulnerability in Rivers State. The methodology comprises of the acquisition of primary and secondary data, image pre-processing, image classification, DEM processing, classification and standardization of factors, development of pairwise comparism, and weighted linear combination analysis. The study revealed three distinct coastal erosion vulnerability zones: high, moderate, and low vulnerability. The high vulnerability zone encompassed a total expanse of 545.29 square kilometers, constituting 6.38% of the study area. In contrast, the moderate and low vulnerability zones covered 1941.33 square kilometers and 6052.51 square kilometers, respectively, making up 22.73% and 70.89% of the total area. Bonny (139.28 sq km) was ranked as the most vulnerable due to its role as an oil and gas hub. Degema (111.28 sq km) ranked second and requires urgent erosion control. Okrika and Andoni (71.73 sq km and 62.20 sq km) were third and fourth respectively. It is recommended that an advocate for the systematic approach to coastal vulnerability zoning be introduced in the study. The categorization of areas into high, moderate, and low vulnerability zones provides a standardized framework for assessing coastal regions' susceptibility to erosion. This approach can be applied to other regions to facilitate consistent vulnerability assessments.

GET 190–2023 state primary special standard of the unit of acceleration in gravimetry: reproduction and dissemination of the unit under the influence of geophysical factors

GET 190–2023 state primary special standard of the unit of acceleration in gravimetry: reproduction and dissemination of the unit under the influence of geophysical factors

State primary special standard of acceleration unit in the field of gravimetry GET 190-2023: reproduction and transmission of the unit under the influence of geophysical factors

The relevance of research on the reproduction and transmission of the acceleration unit in gravimetry is determined by the development of measuring instruments for the absolute value of the acceleration of free fall and its changes. Qualitative and quantitative changes in the instrument base are due to the requirements of applied tasks solved using gravimetric data in such fields as geodesy, navigation, geodynamics, as well as the expansion of the field of practical application of absolute gravimeters. At the same time, in order to solve applied problems, along with accuracy requirements at a level close to the maximum achievable at the current level of technology development, maximum territorial coverage of measurement sites within the entire territory of the Russian Federation is often necessary. The accuracy of the results obtained with the help of measuring instruments is determined by the level of their metrological support, the main stages of which are the reproduction of the corresponding unit by the standard and its transfer to the measuring instrument. An analysis of possible sources of errors in gravimetric equipment has shown that when reproducing and transmitting the acceleration unit in gravimetry, it is necessary to take into account the influence of geophysical factors that manifest themselves as additional accelerations of a gravitational or inertial nature. The distribution of the gravitational field within a gravimetric point can manifest itself as an additional constant acceleration. Seismic processes and lunar and solar tides manifest themselves as variable accelerations. For various stages of metrological support of gravimetric devices, the mechanisms of the effects of such accelerations have been studied, as well as methods for accounting and reducing their influence using additional equipment have been developed. An additional gravimetric point with a cryogenic relative gravimeter and a broadband seismometer, as well as transported absolute ballistic and relative quartz gravimeters, were introduced into the State primary special standard of acceleration units in the field of gravimetry GET 190-2023.

Radiative Regime According to the New RAD-MSU(BSRN) Complex in Moscow: The Roles of Aerosol, Surface Albedo, and Sunshine Duration

The radiative budget is one of the key factors that influences climate change. The aim of this study was to analyze the radiative regime in Moscow using the RAD-MSU(BSRN) complex and to estimate the radiative effects of the main geophysical factors during the 2021–2023 period. This complex is equipped and maintained according to the recommendations of the Baseline Surface Radiation Network; however, it is not a part of this network. In cloudless conditions, the decrease in global shortwave irradiance (Q) is about 18–22% due to the aerosol content with a pronounced change in the direct to diffuse ratio. In winter, the increase in Q is about 45 W/m2 (or 9%) at h = 30° due to a high surface albedo and reduced aerosol and water vapor contents, while the net shortwave irradiance (Bsh) demonstrates a significant decrease due to the prevailing effects of snow albedo. In cloudy conditions, a nonlinear dependence of Q and Bsh cloud transmittance on the relative sunshine duration is observed. The mean changes in Q for the 2021–2023 against the 1955–2020 period are characterized by negative anomalies (−22%) in winter and positive anomalies in summer (+3%) due to the changes in cloudiness. This is in line with the global tendencies in the long-term changes in shortwave irradiance in moderate climates in Europe in recent years.

Forest Cover and Locality Regulate Response of Watershed Discharge to Rainfall Variability in Caribbean Region

Reforestation often occurs when the economy shifts from agriculture to industry and services such as tourism. However, there is a lack of coherent knowledge and investigation about the impact of reforestation in the tropics on hydrological variability as well as flood risks. It is unclear how changes in forest cover and pattern will affect flood risks and watershed response to future altered rainfall intensity. This study uses the Soil Water Assessment Tool (SWAT+) to simulate the impact of reforestation, the locality of forest, and the concentrated rainfall on the hydrology of the largest watershed in Puerto Rico. SWAT+ is a computer model simulating watershed hydrology driven by meteorological input and the characteristics of soils and land use. We hypothesized that increased forest cover, especially at low elevation range, would reduce flood risk and that reduced rain days while maintaining the mean annual rainfall invariant would increase stream discharge variability. We found that reforestation significantly reduced large discharges but increased small discharges; that forest at low elevation tended to reduce large and extreme discharges in comparison with forest at high elevation; and that more concentrated rainfall not only increased the rainfall variability but also increased the discharge variability. However, both the impact of shifting forest locality and the response of watershed to altered rainfall intensity strongly depended on geophysical factors such as ranges of elevation and slope. Moving forests to lower elevation in subbasins with steeper slopes showed a stronger reduction in extreme discharges than in subbasins with flatter slopes. On the other hand, subbasins with steeper slopes tended to response more strongly to more concentrated rainfall with greater increase in discharge variability than subbasins with flatter slopes. To cope with future increased climate variability, our results favor reforestation at lower elevation for watershed with large elevation ranges and steep slopes.

Demystifying Misconceptions on Key Tenets of Quality Basic Education in Chikomba District, Zimbabwe: A Systematic Literature Review

Educational stakeholders in Zimbabwe have been expressing sentiments on deteriorating basic quality education. Accordingly, this led to continuous updates of curriculum peculiarly over the past decade to embrace qualities of basic education. Thus, this research paper sought to: explore fundamental features of quality basic education, analyse challenges impeding it and propose strategies to overcome obstacles for quality basic education in Chikomba District, Zimbabwe. Research methodology adopted was Systematic Literature Review. A comprehensive 7 steps research design was crafted from formulation of review questions to interpretation of results. To enhance accuracy and consistency, a well detailed structured critical Systematic Review Chart was followed. Twenty-five sources were finally selected and reviewed from a total of 35. These were government publications, journals, books, articles, published research papers, newspapers and international organisations’ reports. Validity and reliability were enhanced through utilisation of in-depth analysis of data collection methods, administration of check list and use of three experienced reviewers. The findings revealed that, basic quality education should encompass qualified teachers; competency-based curriculum; inclusivity; learner’s engagement; innovativeness and creativity; practical surviving skills; digital infrastructure; abundant resources and quality assurance systems. 50% of sources reflected economic challenges, 20% technological hindrances, 10% unconducive educational policies, 15% socio-cultural barriers and 5% indicated geo-physical factors. The research proposes strategies which are linked to recommendations for attainment of quality basic education. These include: stakeholder engagement, digital infrastructure, resources mobilisation, training and employment of more teachers. Furthermore, regular competency curriculum review, quality assurance, supportive educational and inclusivity policies towards women and disabled. Conclusively, the research noted that qualities of basic education are multifaceted and Chikomba District will be used as a field for data collection to test the hypothesis.

Urban flood hazard assessment in Awka metropolis using multi-criteria decision process

Urban flooding is an escalating global threat, and Awka Metropolis in Anambra state Nigeria is no exception. The city's rapid urbanization and inadequate infrastructure have left it increasingly vulnerable to flooding, exacerbated by the impacts of climate change. Anticipated flood effects include disruption of daily life, infrastructure damage, and threats to public safety, necessitating urgent attention. This study presents a comprehensive assessment of urban flood hazards in Awka Metropolis, utilizing an integrated approach combining the Analytical Hierarchy Process (AHP) and Flood Hazard Index (FHI) to gauge the city's flood vulnerability. The primary objectives were to identify key geophysical factors contributing to flooding, categorize these factors by their vulnerability, determine their reliability indices, delineate flood-prone zones, and generate a spatial flood extent map. The methodology encompassed data acquisition, pre-processing, Flood Modeling (evaluating slope, Elevation, Drainage Network, and flow accumulation), the application of Analytical Hierarchy Process, and the utilization of the Flood Hazard Index. The results classified Awka Metropolis into three flood risk zones: high (837.84 hectares, 14.70%), moderate (2182.65 hectares, 38.30%), and low (2678.45 hectares, 46.99%). These findings provide indispensable insights into the distribution of flood hazards across the city, enabling urban planners and authorities to strategically allocate resources, prioritize mitigation initiatives, and formulate targeted flood risk reduction strategies. Importantly, the incorporation of stakeholder input enhances the study's practical relevance and applicability in real-world urban planning and disaster management scenarios. In conclusion, this research offers a robust and multidimensional framework for assessing urban flood hazards in Awka Metropolis. The synergy of the Analytical Hierarchy Process and Flood Hazard Index equips urban planners, policymakers, and disaster management agencies to proactively tackle the mounting urban flooding challenges. The study's outcomes contribute to the development of sustainable flood risk reduction measures, ultimately enhancing the resilience of Awka Metropolis to future flood events.

Engineering Solutions for Mountainous Road Construction: A Comprehensive Study on Geophysical and Geotechnical Factors Influencing Slope Stability

This research paper investigates engineering solutions for mountainous road construction, focusing on the intricate interplay between geophysical and geotechnical factors impacting slope stability. Recognizing the unique challenges posed by mountainous terrain, the study employs a comprehensive approach to analyze the geological characteristics and assess potential instability issues. Through a thorough examination of the site-specific conditions, the paper proposes innovative engineering interventions tailored to enhance slope stability and ensure the durability of mountain roads. The findings contribute valuable insights to the field of civil engineering, providing a roadmap for sustainable and resilient infrastructure development in challenging topographies. Keywords: Mountainous Road Construction, Geophysical Factors, Geotechnical Factors, Slope Stability, Engineering Solutions, Comprehensive Study

New insights into crustal and geological structures beneath the Southern Benue trough of Nigeria and parts of Cameroon Volcanic Line from tailored gravity data

We utilized a high-resolution tailored gravity dataset to investigate the geological structure beneath the Southern Benue Trough of Nigeria and along the Cameroon Volcanic Line (CVL). The tailored gravity data was obtained by applying a stochastic combination technique to integrate global gravity field model, terrestrial gravity data, and residual gravity data over the study area. We then carried out gravity techniques to compile the Bouguer gravity map and to estimate the crustal thickness. To obtain suitable estimates of the reference depth and density contrast of the Moho interface, we fitted the gravimetrically determined Moho geometry to the seismic estimates by minimizing the Root-Mean-Square of their differences. A minimum RMS of 3.6 km at a reference depth of 26 km and a density contrast of 450 kgm−3 was achieved over the study area. Our results reveal a dense magmatic feature criss-crossing the central portion of the study area. This phenomenon led to a thinning of the crust and formation of various geological structures, mainly at the southern end. We could see a very thick sedimentary cover within some of these structures possibly occasioned by compressional and extensional tectonic forces acting at the southwest end. Our study reveals that these compacted sedimentary covers could be important habitats for mineralization. We have also been able to refine and depict the lateral extent of the crustal architecture at a fine scale using our tailored gravity dataset. We concluded that the tectonic events beneath the study area are complex and point to several geophysical factors earlier revealed in published studies. However, a narrowing of two or more conjugate plates (margins) propelled by an upward force may have primarily led to the upward displacement of some of the magmas in-between those plates forming the intrusive rocks.

Geophysical Processes in the Arctic and the System Analysis of their Impact on Operation and Development of the Transport Infrastructure

The scientific research that has become the subject of consideration in this article is related to assessment of the influence of geophysical factors on sustainable functioning of transport systems and the system analysis of their impact on the transport infrastructure at the Arctic latitudes. The research is a new direction in the field of study of operational reliability of transport systems and scientific support for development of transport infrastructure in the Russian Arctic.The paper touches upon the issues of reliability and possible failures of technical equipment under the influence of space weather, and also discusses multifaceted problems of safety and efficiency of development of transport systems considering new data on the structure and properties of the lithosphere referring to thawing of permafrost and mineral deposits. A separate section is devoted to new information on seismic activity and seismic hazard assessment in areas of operation and promising development of the transport infrastructure of the Arctic zone of the Russian Federation (AZRF).Intellectual accounting and generalisation of the obtained interdisciplinary results together with their visualisation are provided by geoinformatics methods. The paper presents also the results of adoption of modern geodatabase management systems, of the application of modern technologies of geoportals and interactive spherical visualisations for qualitative presentation of new geophysical knowledge obtained in the course of research.

Effects of Wetland Degradation on Community Livelihoods: A Case of Mabengere Wetland in Kisiita Sub County, Kakumiro District, Uganda

Wetlands in Uganda play vital ecological, economic, socio-cultural, scientific and recreational purposes and yet they are currently threatened by anthropogenic and bio geophysical factors. The current study was initiated to determine the drivers of wetland degradation; and to assess the benefits and costs as a result of wetland degradation, to members of the local community in Kakumiro district, Uganda. A cross sectional research design that involved the collection of both quantitative and qualitative data from three hundred and eighty-seven respondents was used. Data were collected using a questionnaire, Key informant interview guide from the key informants and observation check list. Key findings revealed that sand and clay mining, agricultural activities, gathering building materials were the key activities carried out, which significantly affected the wetlands at P&lt;0.05. In addition, the activities carried out in the wetlands significantly improved the livelihoods of the people living around them at P&lt;0.05. The water levels in the wetlands were reduced that led to shortage of portable water and the water for watering animals, and also led to outbreak of fires which contributed to a reduction in the wetland’s biodiversity. This was confirmed by the Chi-square test which revealed that degradation of wetlands contributed to the costs incurred by members of the local community at P&lt;0.05. It was therefore recommended that alternative sources of energy and building materials be availed like planting of upland trees. Also, there should be awareness intensification to members of the local community about the values and uses of wetlands aimed at scaling down their degradation.

Urban Vulnerability and Adaptation Strategies against Recurrent Climate Risks in Central Africa: Evidence from N’Djaména City (Chad)

Climate change and its corollaries suggest that urban planning tools and strategies need to integrate adaptation and resilience approaches into urban development. This study aims to inform decision makers and the scientific community of the importance of appropriating data on urban adaptation and resilience strategies in the city of N’Djaména. After sampling 519 city dwellers, oriented questionnaires and focus groups were used to collect socio-demographic parameters, major climate risks, their impacts on urban issues and the urban resilience strategies employed. The various exposure and impact indices were used to identify and prioritize climate risks and urban exposure issues with the populations concerned. The study highlighted three major climatic hazards, namely, flooding, heat waves and strong winds, and their impact on social and community facilities, the living environment and human health. Ten vulnerability factors have been identified, of which the intrinsically geophysical factors are most familiar to the city’s population. The principal component analysis (PCA) illustrates ten (10) strategies for adaptation and resilience to urban climate risks. To meet the climatic challenges in urban areas, this study makes several short-, medium- and long-term recommendations to decision makers.

Microbial activity contributes to spatial heterogeneity of wetland methane fluxes.

The emission of methane from wetlands is spatially heterogeneous, as concurrently measured surface fluxes can vary by orders of magnitude within the span of a few meters. Despite extensive study and the climatic significance of these emissions, it remains unclear what drives large, within-site variations. While geophysical factors (e.g., soil temperature) are known to correlate with methane (CH4) flux, measurable variance in these parameters often declines as spatial and temporal scales become finer. As methane emitted from wetlands is the direct, net product of microbial metabolisms which both produce and degrade CH4, it stands to reason that characterizing the spatial variability of microbial communities within a wetland-both horizontally and vertically-may help explain observed variances in flux. To that end, we surveyed microbial communities to a depth of 1 m across an ombrotrophic peat bog in Maine, USA using amplicon sequencing and gene expression techniques. Surface methane fluxes and geophysical factors were concurrently measured. Across the first meter of peat at the site, we observed significant changes in the abundance and composition of methanogenic taxa at every depth sampled, with variance in methanogen abundance explaining 70% of flux heterogeneity at a subset of plots. Among measured environmental factors, only peat depth emerged as correlated with flux, and had significant impact on the abundance and composition of methane-cycling communities. These conclusions suggest that a heightened awareness of how microbial communities are structured and spatially distributed within wetlands could offer improved insights into predicting CH4 flux dynamics. IMPORTANCE Globally, wetlands are one of the largest sources of methane (CH4), a greenhouse gas with a warming impact significantly greater than CO2. Methane produced in wetlands is the byproduct of a group of microorganisms which convert organic carbon into CH4. Despite our knowledge of how this process works, it is still unclear what drives dramatic, localized (<10 m) variance in emission rates from the surface of wetlands. While environmental conditions, like soil temperature or water table depth, correlate with methane flux when variance in these factors is large (e.g., spring vs fall), the explanatory power of these variables decline when spatial and temporal scales become smaller. As methane fluxes are the direct product of microbial activity, we profiled how the microbial community varied, both horizontally and vertically, across a peat bog in Maine, USA, finding that variance in microbial communities was likely contributing to much of the observed variance in flux.

Dynamics of Mid‐Latitude Sporadic‐E and Its Impact on HF Propagation in the North American Sector

AbstractSporadic‐E (Es) are thin layers of enhanced ionization observed in the E‐region, typically between 95 and 120 km altitude. Es plays an important role in controlling the dynamics of the upper atmosphere and it is necessary to understand the geophysical factors influencing Es from both the scientific and operational perspectives. While the wind‐shear theory is widely accepted as an important mechanism responsible for the generation of Es, there are still gaps in the current state of our knowledge. For example, we are yet to determine precisely how changes in the dynamics of horizontal winds impact the formation, altitude, and destruction of Es layers. In this study, we report results from a coordinated experimental campaign between the Millstone Hill Incoherent Scatter Radar, the SuperDARN radar at Blackstone, and the Millstone Hill Digisonde to monitor the dynamics of mid‐latitude Es layers. We report observations during a 15‐hr window between 13 UT on 3 June 2022 and 4 UT on 4 June 2022, which was marked by the presence of a strong Es layer. We find that the height of the Es layer is collocated with strong vertical shears in atmospheric tides and that the zonal wind shears play a more important role than meridional wind shears in generating Es, especially at lower altitudes. Finally, we show that in the presence of Es, SuperDARN ground backscatter moves to closer ranges, and the height and critical frequency of the Es layer have a significant impact on the location and intensity of HF ground scatter.

Earthquake spatial probability and hazard estimation using various explainable AI (XAI) models at the Arabian peninsula

Earthquakes are the most destructive natural hazards because of their adversely severe impacts on urban areas. Earthquakes affect people's lives and properties, thus captivating the extensive attention of seismologists. Carrying out probability and hazard assessment for the prevention, and reduction of mega-events and recovery will be of great significance in affected areas. Given that limited studies have attempted to estimate earthquake Spatial Probability Assessment (SPA) in the Arabian Peninsula, this study aims to evaluate the SPA and Earthquake Hazard Assessment (EHA). This study implements and evaluates various machine learning and explainable-AI (XAI) techniques for the estimation of SPA and EHA in the Arabian Peninsula, explores the contribution and highlights the importance of different factors in the development of AI-based models. A total of twelve factors ranging from seismological to geophysical factors were evaluated. Two machine learning models namely Light Gradient Boosting Machine (LightGBM) and deep Recurrent Neural Networks (RNN) along with three XAI approaches (i.e, Smart predictor, Smart Explainer and Local Interpretable Model-Agnostic Explanation (LIME) model) were investigated. Results of the comparative earthquake SPA estimation demonstrated that the accuracy of 89% and 87% were achieved by LightGBM and RNN models. Moreover, the results of the XAI models show that the Smart Predictor provides better spatial outputs than the other evaluated XAI models. The stable factors identified by Smart Predictor were magnitude variation and earthquake frequency whereas the important factors were magnitude variation, earthquake frequency, depth variation, and seismic gap. Collectively, results of SPA show that, the Gulf of Aden, Red Sea, Iran, and Turkey are falling under a very-high SPA index (0.991–1). Correspondingly, Gulf areas, coastal areas of Saudi Arabia, and areas in the Zagros fault and Anatolian fault zone fall under a very-high hazard zone. This research could support planners, and decision-makers for emergency planning, infrastructure development, and reconstruction projects.

Upwelling processes driven by contributions from wind and current in the Southwest East Sea (Japan Sea)

The occurrence of coastal upwelling is influenced by the intensity and duration of sea surface wind stress and geophysical components such as vertical stratification, bottom topography, and the entrainment of water masses. In addition, strong alongshore currents can drive upwelling. Accordingly, this study analyzes how wind stress and ocean currents contribute to changing coastal upwelling along the southwest coast of the East Sea (Japan Sea), which has not yet been reported quantitatively. This study aims to estimate each geophysical factor affecting upwelling processes using the Upwelling Age index. The index assesses the major contributors to the upwelling process using the relationship between physical forcing and upwelling water fraction estimated from shipboard hydrographic data from January 1993 to October 2018. These findings reveal that wind-driven upwelling was dominant off the northern coast. In contrast, current-driven upwelling prevailed off the southern coast. These results suggest that persistent alongshore currents through the Korea Strait make the southern region a prolific upwelling area. Accordingly, it can shed light on the mechanisms of coastal upwelling in the study area, which is crucial for understanding the influence of physical forces on ocean ecosystems.