bluuebunny/crossref_metadata_2025 huggingface dataset:
A geochemical reevaluation of caldera-forming eruption deposits in the Upper Borrowdale Volcanic Group, English Lake District.
Authors: McGowan Edward , Barry Tiffany , Branney Michael
Published: March 2024

Caldera-forming eruptions sequences produce a wide range of volcanogenic sedimentary deposits, from primary mesobreccia (blocks > 1m) that form from the collapse of caldera wall scarps during the eruption, to co-ignimbrite ash plumes (particles < 2mm) deposited during the waning of outflowing pyroclastic density currents, and even secondary aqueously reworked sediments deposited within caldera lakes. Understanding the temporal and special distribution of these deposits is vital to both locate and reconstruct the collapse sequence of these catastrophic events. However, research of caldera volcanoes is greatly hindered at modern examples due to subsequent burial of their own deposits.Ordovician deposits (452 Ma) of the Borrowdale Volcanic Group (BVG) in the English Lake District are dominated by large-scale, caldera-forming deposits that have been tectonically uplifted and dissected by glacial erosion. Each of the BVG calderas have the potential to provide a wealth of knowledge regarding how calderas erupt, collapse, and continue to shape geological processes when their explosive activity ceases. However, due to intense faulting, alteration, and impersistent exposure across the Lake District, in-depth research of these calderas has been largely prevented using standard field-mapping techniques. This leaves most of the understanding for the overall nested caldera complex to be inferred.This investigation utilizes whole-rock geochemistry as the primary method to establish correlations between potential large-scale, caldera-forming pyroclastic deposits across large distances. Once the extent of each deposit was determined, they were individually traced back to their source vents. Detailed fieldwork was then conducted to identify characteristic caldera-forming features, such as rapid thickness changes over volcanotectonic faults, and extensive intercalated mesobreccia deposits.Geochemical analysis of immobile elements, including Nb, Th, Y, and Zr, of potential caldera-forming pyroclastic deposits has allowed for several notable correlations to be established, or disproven. Firstly, proximal outflow sheets from Langdale Caldera have been successfully correlated to pyroclastic sheets over 15 km from the caldera margin and suggest a multi-phase collapse sequence. Secondly, significant differences in the geochemistry of deposits associated with the Lincomb Tarns Formation (> 500 km2 ignimbrite) indicates the presence numerous pyroclastic sheets, originating from two separate caldera volcanoes within the Helvellyn and Ambleside areas. Finally, geochemical variations within the Haweswater ‘caldera’ infill deposit prove that sudden thickness changes, previously associated with syn-collapse volcanotectonic faulting, are the result of separate eruption events that have since between adjacently faulted.
Best practices for the sustainable management of the shallow geothermal energy resource in urban areas: insights from the case study of the City of Milan
Authors: Previati Alberto , Presta Asciutto Alberto , Silvestri Valerio , Crosta Giovanni
Published: March 2024

Recent EU directives and national regulations have encouraged the development of shallow geothermal energy as a renewable, low-emission source. Many cities in Europe are located in suitable areas with high geothermal potential and are therefore experiencing strong growth in the application of this technology for heating/cooling. On the other hand, densely populated urban areas experiencing a rapid development of shallow geothermal applications require appropriate tools to monitor and model the associated effects on both the quality and quantity of the available resource.This work presents the case study of the metropolitan area of Milan, where the total number of geothermal wells (GWHP) has increased significantly in the last 5 years, covering a total thermal energy demand (including heating and cooling) from about 40 to 400 GWh/a. This very rapid growth and the resulting criticalities motivated the technical agencies and the stakeholders to improve the management of the shallow geothermal resource, which was addressed in the following steps.1) Define common requirements for the development of a database of shallow geothermal installations, including the hydraulic and thermal regimes of the systems, and identify essential monitoring objectives for a better management of the subsurface low enthalpy thermal resource;2) Study the cumulative impact of the existing geothermal systems in the entire Milan metropolitan area, delineating thermal capture and thermal disturbance zones using large-scale analytical and numerical models;3) Assess the hydrogeological and subsurface thermal budgets on a regular grid basis to highlight the most critical areas in terms of hydrogeological (due to systems without groundwater reinjection) and thermal stresses (due to highly thermally unbalanced configurations).The development of these tools and the implementation of a semi-automatic updating procedure aim to streamline the management of new requests with a quantitative view of the current exploitation of the geothermal resource in the Milan metropolitan area. Moreover, the implementation of future demand scenarios will improve the sustainability and reduce the risks of existing and planned systems.
Heating and cooling with aquifer thermal energy storage (ATES) in cities
Authors: Blum Philipp , Lee Haegyeong , Menberg Kathrin , Stemmle Ruben
Published: March 2024

Aquifer thermal energy storage (ATES) is a promising technology for sustainable and climate-friendly space heating and cooling which can contribute to lower greenhouse gas (GHG) emissions. Using 3D heat transport models, this study quantifies the technical potential of shallow low-temperature ATES in the city of Freiburg, Germany. The numerical models consider various ATES configurations and different hydrogeological subsurface characteristics relevant for the study area. Based on the modeling results, spatially resolved ATES power densities for heating and cooling are determined and compared to the space heating and cooling energy demands. High ambient groundwater flow velocities of up to 13 m d-1 cause relatively high storage energy losses resulting in maximum ATES power densities of 3.2 W m-2. Until now, these still reveal substantial heating and cooling energy supply rates achievable by ATES systems. While heating supply rates of larger than 60 % are determined for about 50 % of all residential buildings in the study area, the cooling energy demand could be supplied entirely by ATES systems for 92 % of the buildings. In addition, ATES heating alone could result in greenhouse gas emission savings of up to about 70,000 tCO2eq a‑1. The proposed modeling approach in this study can also be applied in other urban areas with similar hydrogeological conditions to obtain estimations of local ATES supply rates and support city-scale energy planning for heating and cooling.
Profiles of the Venusian ionosphere and neutral atmosphere derived from reprocessed Pioneer Venus radio occultation measurements
Authors: Oschlisniok Janusz , Pätzold Martin , Tellmann Silvia , Peter Kerstin , Hahn Matthias
Published: March 2024

The radio occultation technique is a powerful tool to probe the vertical structure and composition of Venus' atmosphere. By measuring the bending and attenuation of radio waves as they pass through the planet's ionosphere and neutral atmosphere, radio occultation allows to derive valuable information about temperature, pressure, density, and amount of sulfuric acid vapor and sulfur dioxide in the Venusian atmosphere. It has been employed to probe the vertical structure and composition of Venus' atmosphere since the 1960s. First measurements were carried out in 1967 with the Mariner V spacecraft. Two measurements were performed at the equatorial day side and nightside. Later, the Mariner 10 flyby on Venus in 1974 was used to conduct one radio occultation measurement at the equatorial region. In the 1970s and 1980s, the Venera spacecrafts have provided ionospheric and neutral atmospheric profiles.The first extended study covering a wide range of latitudes was performed with the Pioneer Venus Orbiter (PVO) mission between the years 1978 and 1992. The ionosphere and neutral atmosphere were sounded with X- and S-band radio waves using a 1.09-m High Gain Antenna.We have recalculated the atmospheric profiles from the PVO mission. The basis for the recalculation formed an improved reconstructed orbit of PVO. We present and discuss the ionospheric and neutral atmospheric profiles reconstructed from the Pioneer Venus mission. Further, we compare the profiles with the original PVO results and with atmospheric profiles derived from other radio occultation studies at Venus. 
Methane leak or false positive? An automated probabilistic treatment of detected emissions from oil and gas facilities in multi-spectral satellite imagery at continental scale.
Authors: Rischard Maxime , Schissel Colette , Niazi Mahrukh
Published: March 2024

Satellite observations are an important tool in large emission event detection and global monitoring of methane emissions from oil and gas facilities, but current satellite-based methods face significant uncertainty. One of the major sources of uncertainty is a high rate of false positives. Current methods to mitigate false positive rates typically involve manual inspection of plume imagery, a time-consuming process which introduces human error. The Sentinel-2 multispectral satellite is widely used in global methane observation, as methane enhancements can be identified by a signal in shortwave infrared bands 11 and 12.  However, physical, biological and other anthropogenic processes can have a similar spectral signature, leading to a high rate of false positives. We present an empirical False Discovery Rate approach for quantifying the false positive probability for a given candidate plume. Imagery data is divided into a near-to-well set (within 200m of oil and gas infrastructure) and a far-from-well control set (between 400m-1200m away from oil and gas infrastructure), which is conservatively assumed to consist entirely of false positives. With these datasets, we define the probability of a false positive given proximity to oil and gas infrastructure as a function of plume quality and distance to infrastructure.  The results from this approach are shown for a case study over the contiguous United States, where we found a strong relationship between the selected plume quality metrics, distance to infrastructure and the false positive probability. We also identified significant differences in plume characteristics between the near-to-well and far-from-well datasets.  This work presents a more efficient and data-driven false positive algorithm, which can significantly reduce the manual step in false positive identification, resulting in larger scale deployment and data processing of satellite-based methane emission monitoring.
Urban Flood Extent Extraction and Type Recognition Based on Multiple Convolutional Neural Networks
Authors: Wang Ziming , Zhang Ce
Published: March 2024

With the increasing frequency of global extreme weather events and urbanization accelerates, the probability of urban flooding has significantly increased, posing a grave threat to both property and lives. Creating accurate flood maps is a critical component of effective emergency management for urban floods. However, current research primarily focuses on the extent of urban flood, with little consideration given to its type. Different types of floods often have varying water components and sediments, necessitating the identification of flood types during mapping to provide targeted relief. This paper proposes a method using multiple Convolutional Neural Networks (CNNs) that combines U-Net and ResNet architectures for urban flood extent extraction and type classification. The proposed method achieved 97.1% accuracy in flood extent extraction and 91% accuracy in flood type classification, demonstrating its accuracy in urban flood mapping. Furthermore, the research was validated using a global dataset, covering six continents and 20 countries, encompassing samples with diverse dimensions and geographical features, showcasing the robustness and practicality of the model in various regions.Keywords: Urban flood mapping, Flood type, Deep learning, CNN, Classification
Two-year observations of aerosol size distributions: investigating new particle formation at coastal and rural sites in the Netherlands
Authors: Liu Xinya , Henzing Bas , Mulder Jan , Dusek Ulrike
Published: March 2024

This study aims to analyze the dynamics of aerosol behavior, particularly focusing on particle number size distribution (PNSD) in contrasting environments — coastal and rural areas of the Netherlands. Our goal is to interpret the environmental factors and mechanisms influencing New Particle Formation (NPF) events in these distinct geographic settings, thereby enhancing our understanding of aerosol dynamics in varied environmental conditions. Our results indicate significant differences in particle number concentrations between the sites, with Cabauw showing notably higher concentrations, largely due to Ultrafine Particles (UFPs). Wind patterns strongly influence UFP levels, particularly winds from the direction of Amsterdam airport and the Rotterdam port area. However, the two sites exhibited good agreement (r²=0.62) in the concentration of accumulation mode particles, suggesting a regional rather than local source. Seasonal variations in nuclei mode particles were observed for both sites, with concentrations peaking in summer and diminishing in winter. Our analysis extends to PNSD clusters and NPF classes. The results suggest that NPF events are typically associated with high solar radiation, lower relative humidity, higher temperature, and higher SO2 and O3, but lower NOx. The growth of these newly formed particles often relies on stable diffusion radiation conditions, while frequent cloud occurrence impedes particle growth. Additionally, particle size growth is often accompanied by increased concentrations of organics, nitrate, and ammonium. Notably, two distinct NPF episodes in the morning and at noon were observed at Cabauw. Suppressed growth of morning particles often coincides with higher NOx concentrations. In contrast, Lutjewad often experienced noon NPF events, which demonstrated sustained growth in particle size until the following day. These findings underscore the influence of local environmental conditions on aerosol dynamics.
Subsurface soil and lithology alteration shaping degassing at Krafla caldera, Iceland
Authors: Davoli Roberto , Engels Katharina , Montanaro Cristian , Ricci Tullio , Sciarra Alessandra , Scheu Bettina
Published: March 2024

Alteration by rock-fluid interaction can significantly impact rock and soil properties influencing fluid flow within hydrothermal aquifers, and shaping surface features and degassing in geothermal settings over time. Hence, the understanding of the spatial distribution of thermal manifestations in correlation with the geological setting and alteration type remains essential for unravelling the processes controlling the transport of fluids from within the hydrothermal aquifers to the surface.Previous studies focused on the effect of alteration within hydrothermal aquifers on a scale of hundreds of meters. In contrast, limited research has explored the influence of subsurface lithologies – including their intrinsic and altered permeability – and their spatial distribution on degassing activity. This study examines subsoil portions across the active geothermal fields of Krafla caldera in Iceland, to explore the relationship between various soils/lithologies and primary degassing areas. In particular, we investigate how hydrothermal alteration influences the petrophysical characteristics of these lithologies, thereby modulating surface-level fluid circulation.In two field campaigns carried out in 2022 and 2023, we assessed the in situ petrophysical properties of over 200 samples across 22 sites in the Víti and Hveragil regions. Moreover, we conducted subsoil diffuse CO2 flux measurements for specific profiles. Field permeability ranged from 10-11 to 10-16 m2, with CO2 fluxes varying between 1.25 to 2628.33 g/m2 day. Additionally, we examined the grain size distribution and the componentry of selected subsoil layers.Our findings delineate the presence of both active (thermal) and inactive (non-thermal) regions, depicting the variable impact of hydrothermal alteration on the subsoil properties. In active geothermal sites, the dominance of mineral dissolution/replacement facilitates the formation of preferential pathways for fluid flow. Within inactive areas, mineral cementation of pores and fractures appears to act as barriers to fluid movement. These outcomes offer crucial insights for comprehending and quantifying the effect of hydrothermal alteration on fluid dynamics, shedding light on the progression of surficial manifestations and degassing patterns within active geothermal areas.
Exploring the utility of GRACE measurements for characterizing large regional karst systems
Authors: Orazulike Chibuike , Hartmann Andreas , Xanke Julian , Chen Zhao
Published: March 2024

In the face of climate change and human activities, Groundwater Storage (GWS) in karst aquifers of the Euro-Mediterranean region has experienced a significant decline, particularly across 60-80 percent of its terrain. We undertook a spatiotemporal characterization of karst aquifer dynamics in this region by integrating satellite observations (GRACE) and the process-based model VarKarst that simulates potential groundwater recharge in karst terrain. Utilizing the GLDAS and ERA5-Land datasets, we independently obtained Groundwater Storage Anomalies (GWSA) and Subsurface Water Storage Anomalies (SWSA) by decomposing the terrestrial water storage anomaly (TWSA) detected by GRACE. GWSA focuses explicitly on the saturated part of aquifers, while SWSA considers both the saturated and unsaturated parts. This approach is adopted to better understand the role of soil and epikarst in the groundwater recharge processes in large karst regions. Comparisons of GRACE-derived GWSA and the potential groundwater recharge calculated by the model VarKarst for the period 2002-2019 revealed the steepest GWS declines in the polar(tundra) climate zone of the Alpine region. Recharge trends were mixed, with the strongest decline in polar climates (-3.0mm/year) linked to rising temperatures (evapotranspiration). Incorporating gridded sectoral water withdrawal information is imperative for interpreting the observed spatial patterns of GWSA/SWSA. The temperate climate zones show a strong correlation between SWSA and lagged recharge, which should be due to the flow-regulating role of soil/epikarst. In addition, the current study incorporates spring discharge data from selected karst catchments to evaluate the previous analysis. Spatial scale limitations were identified for small karst catchments, as evidenced by poor correlations with spring discharge, while larger karst catchments show stronger correlations. This research highlights the importance of considering groundwater recharge processes and the epikarst dynamics when using GRACE data to assess regional karst hydrogeology. Such an integrated method will provide a clearer picture of the impacts on GWS under current climatic and anthropogenic stressors.
Promoting Open and Transparent Hydrologic Modeling: Workflows, Tools and Self-Contained Modules
Authors: Knoben Wouter , Clark Martyn , Arnal Louise , Gharari Shervan , Keshavarz Kasra , Liu Hongli , Pietroniro Alain , Shook Kevin , Spiteri Ray , Stadnyk Tricia , Wood Andy
Published: March 2024

Configuring process-based hydrologic models can be a cumbersome task, especially for larger domains. In the past model inputs (data), configuration and analysis code, as well as the source code of the models themselves were only rarely openly available. More recently, the hydrology community is moving toward a more open culture, focused on shareable data, tools and code. Here we present various recent open-source advances along the entire modeling chain. These include:Workflows for model configuration of large-domain hydrologic models, data-driven seasonal streamflow forecasting and forcing data processing;
Tools for the remapping of forcing variables from one set of spatial elements to another;
Tools for adjusting and correcting baseline geofabrics for internal consistency and efficient routing;
Computationally frugal sensitivity analysis methods;
Independent hydrologic process modules for specific geographic landscape features and routing through reservoirs;
Improved numerical methods for model solving and parallelization.
These tools are publicly available with the specific aim to make them useful to others. During this PICO, we welcome discussion about the tools, as well as general discussion about the opportunities and pitfalls surrounding open-source science.
Photosynthetic optical signals studying biogenic volatile organic compound emissions in Scots pine and English oak saplings under drought or warming
Authors: Zhang Chao , Miettinen Iiro , Porcar-Castel Albert , Atherton Jon , Rissanen Kaisa , Aalto Juho , Tykkä Toni , Hellén Heidi , López-Pozo Marina , Fernández-Marín Beatriz , García-Plazaola José Ignacio , Kohl Lukas , Bäck Jaana
Published: March 2024

Biogenic volatile organic compounds (BVOCs), primarily emitted into the atmosphere by terrestrial vegetation through biochemical processes, have key ecological functions in protecting vegetation from biotic or abiotic stresses. However, accurately quantifying and predicting changes in BVOC emissions in response to long-term environmental changes large spatial scales remain challenging. The appropriate tools for observing the BVOC emissions at large scales are still missing. Remote sensing of optical signals is a promising solution to fill spatial knowledge gap. We hypothesize that the carotenoid-related vegetation index, such photochemical reflectance index (PRI), is a promising method to investigate BVOCs emitted by plants based on their functional links with carotenoids and photosynthetic activity.We conducted a leaf-level experiment in greenhouse during the summer of 2022 to investigate how the relationships between PRI and BVOC emissions change in response to drought or heat stresses in Scots pine and English oak saplings during the peak of growing season. We aim to address the following questions: (1) What factors control the relationships between PRI and BVOC emissions in response to mild/extreme drought or heat; (2) Will these controlling factors differ between vegetation species or BVOC emission types (e.g., isoprene and monoterpenes)? (3) Can PRI or other carotenoid-related vegetation indices capture the changes of BVOC emissions in response to drought or heat stresses?We will present our preliminary results. The expected outcomes will give new insight into leaf-level mechanistic links between PRI and BVOC emissions for plants in response to climate drought or warming.
Amphibole breakdown rim textures as archivists of pre-eruptive magmatic processes
Authors: Wallace Paul , H. De Angelis Sarah , Larsen Jessica , Caricchi Luca , Lavallée Yan
Published: March 2024

Amphibole phenocrysts are common in intermediate to felsic magmas where they record information on magma evolution through breakdown rim textures marking shifts in pressure, temperature, volatile concentrations, oxygen fugacity and melt chemistry during ascent. Our ability to track these variables throughout the volcanic plumbing system (e.g., via phase equilibria experiments, geothermobarometry, disequilibrium textures, melt inclusions) has provided the means for interpretating eruption trigger mechanisms, yet a lack of calibrated data on their influence on amphibole stability (and thus reaction rim formation) makes unambiguously distinguishing the mechanism problematic. One such elusive example is the role of CO2 flushing, deemed a likely phenomenon in magmatic systems, precluding an accurate interpretation of natural rim formation, previously assigned to decompression or heating. We performed high-temperature (830–880ºC), high-pressure (120 MPa) experiments to investigate the effects of XCO2 (0.3–0.7) on amphibole reaction rim development in H2O-saturated silicic magmas in shallow volcanic systems, providing new insights for interpreting amphibole rim textures. Our experiments quantify the significant impacts of CO2 on rapidly triggering amphibole breakdown over shorter timescales compared to heating or decompression. 2D textural analysis of the breakdown rim microlites reveal that crystal size, aspect ratio, number density and preferential alignment, together with mineralogy, can be related to a distinct breakdown mechanism. Furthermore, we apply high-resolution electron backscatter diffraction (EBSD) analysis to >100 experimental and natural amphibole reaction rims (Soufrière Hills Volcano, Unzen Volcano, Bezymianny and El Misti). Quantitative mapping reveals systematic variations in crystallographic orientations of the rim microlites relative to the host amphibole, enabling the development of an EBSD criteria that differentiates decompression-, heating-, and CO2-induced amphibole breakdown. The distinct textures produced provides new markers and a new framework for the interpretation of natural rim formation processes. Application of this new quantitative approach over a range of magmatic systems worldwide will improve interpretations of intensive parameters, ascent paths, eruption triggers, and amphibole stability from crystal record archives.
De-risking CO2-Plume Geothermal (CPG) for commercial field deployment
Authors: de Reus Adriaan Jasper , Onishi Tsubasa , Brehme Maren , Games Federico , Hau Kevin P. , Hefny Mahmoud , Kucuk Serhat , Kong Xiang-Zhao , Pokras Daniel , Rangel Jurado Nicolas , Saar Martin O.
Published: March 2024

CO2-Plume Geothermal (CPG) is a technology that employs the benefit of CO2 as a geothermal working fluid to turn CCS into CCUS (Carbon Capture, Utilization and Storage), both by producing more power compared to conventional geothermal systems (Randolph and Saar, 2011), as well as improving the performance of the base CO2 storage project. Following a decade of research, a CPG consortium has started in March 2023 to pave the way for de-risking this emerging technology to a Technology Readiness Level (TRL) of 7. This industry-academic initiative unlocks a larger joint portfolio of opportunities, financing options and domain knowledge, thereby enabling a systematic and standardized approach to evaluating candidate CPG field demonstration sites and concepts. A workflow is presented to define several potential field demonstration concepts, leveraging site-specific risk registers, opportunity framing sessions, competitive scoping and multi-scenario modelling. Using a trade-off table, the highest value field demonstration project can be selected for execution in the subsequent phase of the CPG consortium.
 

 
Current research on Aquifer Thermal Energy Storage in Germany
Authors: Menberg Kathrin , Stemmle Ruben , Bauer Sebastian , Bayer Peter , Blöcher Guido , Kranz Stefan , Felsmann Clemens , Hahn Florian , Shao Haibing , Zosseder Kai , Blum Philipp
Published: March 2024

Around 30 % of Germany's final energy consumption can be attributed to heating and cooling in the building sector. Aquifer Thermal Energy Storage (ATES) allows sustainable and climate-friendly space heating and cooling and is therefore a promising technology that can contribute to decarbonizing this sector. However, further research on ATES is needed to promote the so far limited application of this technology in Germany and other countries. This work therefore gives an overview of current ATES research sites and projects in Germany collected in the project ‘SpeicherCity’. Among other aspects, these projects address hydrogeochemical challenges, potential studies and the integration of ATES into existing energy systems. They include both low-temperature (LT) and high-temperature (HT) ATES systems. This review also provides details on reservoir characteristics and well designs of the individual sites as well as information on the research goals and methods. Based on the comprehensive German research activities on ATES compiled in this work, lessons learned from the research findings and experiences with ATES operation and permission are highlighted.
804 years drought reconstruction based on oak tree rings for Eastern Europe
Authors: Roibu Catalin-Constantin , Ionita Monica , Mursa Andrei , Crivellaro Alan , Wazny Tomasz , Nagavciuc Viorica , Cotos Mihai-Gabriel , Stirbu Marian-Ionut , Asandei Maria-Ecaterina , Andriescu Cosmin-Mihai
Published: March 2024

In this study, we used the Suceava oak tree-ring width chronology to reconstruct the paleo hydroclimatic events in eastern Europe, a region for which high-resolution paleoclimatic evidence is broadly missing. Our regional oak chronology reflects July hydroclimate variability in the form of the twelve months Standardized Precipitation Index over large parts of Romania, Ukraine, and the Republic of Moldova, for which high-resolution paleoclimatic evidence is broadly missing. Most of the reconstructed hydroclimatic extremes back to 1216 CE are confirmed by documentary evidence, and a robust association is found with large-scale atmospheric circulation patterns in the Northern Hemisphere and sea surface temperatures over the North Atlantic. Reconstructed pluvials coincide with a high-pressure system over the North Atlantic Ocean and north-western Europe, and with a low-pressure system over south-western, central, and eastern Europe, whereas historical droughts coincide with a high-pressure system over Europe and a low-pressure system over the central part of the Atlantic Ocean.
Fabric and microstructural analyses of fine-grained glacier salt (Kuh-e-Namak, Dashti, southern Iran)
Authors: Schmitz Julia , Závada Prokop , Urai Janos L.
Published: March 2024

The Kuh-e-Namak diapir consists of a dome and two glaciers and displays flow structures along its profile. Microstructures in salt dome and glaciers are studied for deformation and recrystallization mechanisms in terms of the grain size reduction, grain fabric and its influence on the flow dynamics of the salt system. Using reflected and transmitted light microscopy of gamma-irradiated rock salt thin sections, electron backscatter diffraction and quantitative analysis of digitized microstructures, we show the transition of dislocation creep followed by fluid-assisted recrystallization from the extrusive dome into the glacier where solution-precipitation creep dominates. Along the profile of the glacier, the degree of recrystallization increases, while the porphyroclasts content progressively decreases in favor of the fine-grained matrix. Fabric analysis support the decreasing amount of porphyroclasts and rectangular halite grains. Porphyroclasts in domal salt show the highest misorientation values at the grain boundaries and are consumed by almost misorientation-free, rectangular grains. Further, a development of shape preferred orientation (SPO) in glacier salt is inferred from alignment of the long axes of elongated halite grains visible in the fabric and their rose diagrams. The microstructures are interpreted in terms of combined dislocation creep and solution-precipitation creep. Grain analyses give a mean grain size ranging between 180 and 508 µm and show a moderate aspect ratio around 2, whereas fabric analyses indicate increasing values from dome to glacier salt of up to 4. Subgrain piezometry infers differential stresses of 1.9 to 6.1 MPa, reflecting the high stress in the cold diapir stem, whereas the shear stresses estimated for the glacier are much lower. Estimation for strain rates based on the combination of dislocation creep and solution-precipitation creep are in the orders of magnitude of x10-10 to x 10-09. Well-developed SPO is interpreted to support the hypothesis that solution-precipitation creep is the dominant recrystallization mechanism in glacier salt. Since solution-precipitation creep dominates in salt glaciers at low deviatoric stress, the fine-grained salt deforms much faster than predicted by dislocation creep, allowing salt glaciers to flow.
Enhanced surface temperature over India during 1980–2020 and future projections: causal links of the drivers and trends
Authors: Kumar Rahul , Kuttippurath Jayanarayanan , Gopikrishnan Gopalakrishna Pillai , Kumar Pankaj , Varikoden Hamza
Published: March 2024

The Earth’s surface temperatures have increased significantly since the beginning of industrialisation. The substantial emissions of greenhouse gases have played a role in global warming and the ongoing climate change, with projections indicating continued trends. This study explores the long-term surface temperature trends in India from 1980 to 2020, utilizing surface, satellite, and reanalysis data. Causal discovery is employed to assess the impact of geophysical drivers on temperature changes. Southern India exhibits the highest mean surface temperatures, while the Himalayas experience the lowest, aligning with solar radiation patterns. The causal discovery analysis identifies the varying influence of atmospheric processes, aerosols, and specific humidity on surface temperature. Positive temperature trends are observed during the pre-monsoon (0.1–0.3 °C dec−1) and post-monsoon (0.2–0.4 °C dec−1) seasons in northwest, northeast, and north-central India. Northeast India demonstrates substantial annual (0.22 ± 0.14 °C dec−1) and monsoon (0.24 ± 0.08 °C dec−1) warming. Post-monsoon trends are positive across India, with the western Himalaya (0.2–0.5 °C dec−1) and northeast India (0.1–0.4 °C dec−1) experiencing the highest values. Projections based on the Coupled Model Intercomparison Project 6 (CMIP6) indicate potential temperature increases of 1.1–5.1 °C by 2100 under the Shared Socioeconomic Pathways (SSP5)–8.5 scenario. The escalating temperature trend in India raises concerns, emphasizing the necessity for adaptation and mitigation measures to counteract the adverse impacts of accelerated warming and regional climate change.
Hemispherically symmetric strategies for stratospheric aerosol injection
Authors: Zhang Yan , MacMartin Douglas G. , Visioni Daniele , Bednarz Ewa M. , Kravitz Ben
Published: March 2024

Abstract. Stratospheric aerosol injection (SAI) comes with a wide range of possible design choices, such as the location and timing of the injection. Different stratospheric aerosol injection strategies can yield different climate responses; therefore, understanding the range of possible climate outcomes is crucial to making informed future decisions on SAI, along with the consideration of other factors. Yet, to date, there has been no systematic exploration of a broad range of SAI strategies. This limits the ability to determine which effects are robust across different strategies and which depend on specific injection choices. This study systematically explores how the choice of SAI strategy affects climate responses in one climate model. Here, we introduce four hemispherically symmetric injection strategies, all of which are designed to maintain the same global mean surface temperature: an annual injection at the Equator (EQ), an annual injection of equal amounts of SO2 at 15° N and 15° S (15N+15S), an annual injection of equal amounts of SO2 at 30° N and 30° S (30N+30S), and a polar injection strategy that injects equal amounts of SO2 at 60° N and 60° S only during spring in each hemisphere (60N+60S). We compare these four hemispherically symmetric SAI strategies with a more complex injection strategy that injects different quantities of SO2 at 30° N, 15° N, 15° S, and 30° S in order to maintain not only the global mean surface temperature but also its large-scale horizontal gradients. All five strategies are simulated using version 2 of the Community Earth System Model with the middle atmosphere version of the Whole Atmosphere Community Climate model, version 6, as the atmospheric component, CESM2(WACCM6-MA), with the global warming scenario, Shared Socioeconomic Pathway (SSP)2-4.5. We find that the choice of SAI strategy affects the spatial distribution of aerosol optical depths, injection efficiency, and various surface climate responses. In addition, injecting in the subtropics produces more global cooling per unit injection, with the EQ and the 60N+60S cases requiring, respectively, 59 % and 50 % more injection than the 30N+30S case to meet the same global mean temperature target. Injecting at higher latitudes results in larger Equator-to-pole temperature gradients. While all five strategies restore Arctic September sea ice, the high-latitude injection strategy is more effective due to the SAI-induced cooling occurring preferentially at higher latitudes. These results suggest trade-offs wherein different strategies appear better or worse, depending on which metrics are deemed important.
Assessment of Water Pollution in the Korotoa River: Implications for Ecosystems and Human Welfare in Bogura, Bangladesh
Authors: Das Liton Chandra , Mahmud Sheikh Hayath
Published: March 2024

This study presents a comprehensive evaluation of water quality in the Korotoa River, crucial to Bogura, Bangladesh, as it serves as a critical water supply for the city. Despite its significance, the river faces considerable pollution concerns from untreated pollutants emitted by urban and adjacent regions. The research attempts to analyze the level of water pollution and its repercussions on aquatic ecosystems and human usage. Through systematic water sample collection at numerous locations, the project examines physical and chemical features. Results, assessed against environmental criteria, indicate low dissolved oxygen levels and unsatisfactory water quality measures, particularly around confluence locations. The study exposes significant water pollution, necessitating immediate action to maintain aquatic life, ecosystems, and community well-being. Urgent pollution control actions are necessary to restore and preserve the Korotoa River’s natural balance in Bogura, emphasizing the need for education, monitoring, and research. The research provides insights for authorities and stakeholders to reduce pollution, sustaining the river’s critical role in the region’s biodiversity, agriculture, and human activities.
Comparison of Efficacy and Safety Profile of Conservative Versus Surgical Management of Meniscal Injuries
Authors: Ziyad Ahmad  , Muhammad Hussain  , Muhammad Inam  , Muhammad Izhar  , Tariq Ahmad
Published: March 2024

Background: Surgical management of meniscal tear carries financial implications in resource limited settings like ours. Conservative management could address this issue, if its safety and efficacy profile is better understood. Objectives: The objective of this study was to compare the efficacy and safety of conservative and surgical management of patients with meniscal tear with conservative management.Material and Methods: Descriptive comparative study of 80 patients with meniscal tear, recruited through non-probability convenient sampling technique, was carried out at Orthopedic unit MMC MTI Mardan, during 1st August 2022 and 31st July 2023. Patients were assigned to surgical and conservative group. International Knee Documentation Committee (IKDC) score at baseline and 3 months after treatment were compared for efficacy. Treatment related complications were noted.Results: A total of 80 patients were enrolled with 40 patients in each group (surgical versus conservative). The mean baseline and IKDC score at week 12 in surgical versus conservative group were 45.069±13.301 versus 51.873±17.90 and 79.52±7.40 versus 73.92±11.67 respectively. Surgical group showed treatment response in 37 patients (92.5%) versus 31 (77.5%) in conservative approach (p value 0.060). Surgical site infection was observed in 5 patients (12.5%) in surgical group. Medication related adverse effects were observed in 3 patients (7.5%) in conservative group.Conclusion: No appreciable differences in the clinical results, such as pain reduction or better knee function, between patients who received meniscal surgery and those who underwent conservative treatment for meniscal tears.Keywords: Conservative Approach, Meniscal Injury, Surgical Approach, Treatment Outcomes
Interobserver Reliability of Cervical Vertebral Maturation Staging
Authors: Munawar Manzoor Ali  , Muhammad Noman , Muhammad Azeem  , Gulsana Hashmi  , Muhammad Hassaan Saeed  , Mazhar Hussain
Published: March 2024

Background: the accurate identification of a patient's maturation stage, particularly during the pubertal growth spurt, takes on heightened importance, particularly when addressing cases of dentoskeletal problem Active growth determination is crucial for orthodontic treatment. Objectives: The objective of this study was to determine interobserver reliability of Cervical Vertebrae Maturation (CVM) stagingMaterial and Methods: This cross-sectional correlational study, conducted in the Department of Orthodontics on 70 subjects. Ten orthodontic clinicians, including 4 orthodontists and 6 orthodontic residents, with no prior experience in CVM staging, underwent comprehensive training. The study involved assessing 70 lateral cephalograms with clear visibility of cervical vertebrae, evaluated by two independent examiners using the Baccetti et al. staging system. The collected data were analyzed using R programming, including descriptive statistics for age, Spearman's correlation, and Cohen's Kappa for assessing interobserver agreement, with stratification by gender. Results: The mean age of participants was 12.60±3.93 years, with 38 females (54.29%) and 32 males (45.71%). The study revealed varying levels of agreement between two observers for different CVM stages, ranging from perfect agreement in CS1 to strong agreement in CS3. CS4, CS5, and CS6 also showed varying agreement rates. Additionally, there was robust and statistically significant agreement (p<0.001) between observers in cervical maturation staging, supported by a high Spearman's rho value (r=0.927). Furthermore, substantial agreement was observed with a Kappa value of 0.748, indicating a strong consensus in cervical staging assessments.Conclusion: Cervical vertebral maturation staging is reliable in term of inter-observers agreement. Keywords: Cervical vertebral maturation, Interobserver agreement, Growth assessment
Association of Pre-eclampsia in Women with Advanced Maternal Age
Authors: Zoya Naeem  , Seema Gul  , Atikka Masud  , Faiza Abrar  , Dureshahwar  , Zainab Tahir
Published: March 2024

Background: Preeclampsia: Preeclampsia is a serious condition that typically occurs after the 20th week of pregnancy. Preeclampsia can occur in women of all ages, but the risk increases with certain factors. Objectives: This study aimed to find out the association of pre eclampsia in women with advanced maternal age. Material & Methods: This cross-sectional study was carried out in high dependency unit (HDU) of the Obstetrics and Gynecology Department of the Fauji Foundation Hospital, Rawalpindi, from 30th November 2021 to 29th May 2022. Total of 260 pregnant patients were selected through non-probability, sequential sampling. After taking written informed consent, information on the mother's age (measured in categories) and parity for each patient was gathered on a pre-made Performa. SPSS version 20 software was used to analyze the data. With a p-value of 0.05 considered significant, the chi-square test was employed to compare the maternal age to pre-eclampsia.Results: The mean age of the participants was 27.9± 6.02 years. Pre-eclampsia in pregnant women was discovered in 32 (12.3%) individuals. It was found in 21% of patients having aged <20 years, in 9.0% of patients having age 20-25 years, in 5.4% patients having age 26-30 years, in 14.2% patients having age 31-35 years and 27.5% % in patients having age >35 years and the results were statistically significant.Conclusion: The current study's conclusions indicate that pre-eclampsia affects pregnant women quite frequently and that advance maternal age is a risk factor for the disease.Keywords: Advanced maternal age, Pre-eclampsia, Pregnancy.
Evaluation of Routine Urine Analysis in Diagnosing Urinary Tract Infection among Pediatric Population: A Validation Study
Authors: Tasmia  , Amir Muhammad  , Bakht Beland  , Abbas Zarin
Published: March 2024

Background: Urinary tract infection (UTI) stands out as one of the most common bacterial infections affecting children below the age of five. A valid diagnostic test for UTI is of utmost importance for avoiding bacterial resistance.Objectives: To assess the diagnostic efficacy of routine urine examinations in detecting urinary tract infections in pediatric patients, employing urine culture as the reference standardMaterial and Methods: This diagnostic study was conducted at leady reading hospital, Peshawar. The study employed a non-probability consecutive sampling technique and included 130 children between the ages of 1 and 5 years, regardless of gender, who exhibited symptoms suggestive of urinary tract infections. Exclusion criteria comprised children who had taken antibiotics within the past 48 hours, those with congenital renal anomalies such as renal or renal tumors, renal tract obstruction, and acute renal failure. All participants underwent urine regular examination and urine culture. Sensitivities, specificities, and accuracy were calculated, and the data was further stratified based on gender and age.Results: The mean age of the participants was 2.646±1.32 years. The males were predominant (n-86, 66.2%). The urine examination demonstrated a specificity of 90.91% and a sensitivity of 58.06% in detecting urinary tract infections. A statistically significant difference was observed when comparing the diagnosis of Urinary tract infections using urine culture and urine examination.Conclusion: While urine examinations exhibit satisfactory specificity, their sensitivity is insufficient to be utilized as a reliable diagnostic test for detecting urinary tract infections in children. Clinicians are advised to depend on urine culture for accurate diagnosis in such cases.Keywords: Diagnostic accuracy, Pediatrics, Urine Microbiology, Urinalysis, Urinary tract infection.
Visual Outcome and Complications in Combined Phaco-Vitrectomy Versus Separate Phaco followed by Vitrectomy for Macula Off Rhegmatogenous Retinal Detachment
Authors: Imran Ahmad  , Bilal Khan  , Nazli Gul  , Jawad Humayun  , Fahad Khan
Published: March 2024

Background: Cataract formation is common with pars plana vitrectomy (PPV). Removal of cataract by phacoemulsification can be done combinedly with PPV in the same settings or as separate procedure of phacoemulsification followed by PPV. Objectives: The objective of the study is to check the visual outcome, inflammation and complications in combined phaco-PPV procedure versus separate Phaco followed by PPV.Material and Methods: It was a quasi-experimental study carried out in Ophthalmology Department, Khyber Teaching hospital Peshawar from 1st May 2023 to 31st October 2023. A total of 60 patients were included and divided into 2 groups of 30 patients each. One group undergone combined phaco-PPV and the second group separate phaco followed by PPV. Results: The mean age of participants were 57.8 ± 8.24 years with 58.3% male and 41.7% female. On first post-operative day there was statistically significant difference between the visual acuity, inflammation and complications rate in combined phaco-PPV patients than separate procedure with a p-value of 0.01. There was no statistically significant difference in between the two groups in the final visual acuity, inflammation and complication rate 2 weeks after removal of silicone oil with visual acuity p-value 0.99, inflammation p-value 0.99, complications p-value 0.108Conclusion: There is no significance difference between combined phaco-PPV versus separate phaco followed by PPV in terms of visual acuity, inflammation and complication rate.Keywords: Phacoemulsification, Visual outcome, Vitrectomy