bluuebunny/crossref_metadata_2025 huggingface dataset:
Paleoceanographic reconstruction of the NE shelf of Australia: Insights from surface and subsurface dynamics of the East Australian Current
Authors: Palei Rina Rani , Gupta Anil
Published: March 2024

This study examines marine sediment samples from Ocean Drilling Program Site 1195, Hole B (Lat 20°24.28'S; Long 152°40.24'E; water depth 420 m), located beneath the present-day pathway of the East Australian Current (EAC) on the shelf of Northeast Australia. The EAC represents the western boundary current of the South Pacific subtropical gyre. It originates from the bifurcation of the southern arm of the South Equatorial Current between 15°S and 20°S. The East Australian Current's evolution is linked to the tectonic reorganization of the Indonesian Gateway and the expansion of the West Pacific Warm Pool over geological time. Our analysis of foraminiferal relative abundance data revealed the existence of high surface productivity and reduced subsurface productivity during the 7.5–6.4 Ma Our findings suggest that the northward movement of Papua New Guinea may have commenced after 6.4 Ma, inferred from the consistent thinning of the mixed layer and shallowing of the thermocline. This aligns with the hypothesis proposing the formation of the New Guinea Coastal Undercurrent, potentially caused by the entrapment of a significant portion of the South Equatorial Current against the Papua boundaries, directing it northward. Additionally, we observe a significant decline in the relative abundance of Globigerinoides ruber and a shoaling of the thermocline during the Mid-Pleistocene Transition, coinciding with high surface productivity.
The Ediacaran Apparent Polar Wander Path of the Río de la Plata craton revisited: Paleogeographic implications.
Authors: Cukjati Andres , Franceschinis Pablo , Arrouy María Julia , Gómez-Peral Lucia , Poiré Daniel , Trindade Ricardo , Rapalini Augusto
Published: March 2024

The Ediacaran apparent polar wander path for the Rio de la Plata Craton was analyzed and a new alternative path is presented. This revised path was constructed considering an opposite polarity for poles older than ca. 590 Ma. This path is more consistent with that recently proposed for West Africa, whose large oscillations were attributed to two events of inertial interchange true polar wander (IITPW). A compilation and selection of Ediacaran paleomagnetic data from the main cratons were analyzed leading to a set of global paleogeographic reconstructions throughout the Ediacaran. This model assumes that a “Clymene Ocean” existed between Central Gondwana and West Africa – Amazonia along this period. All cratons with reliable paleomagnetic information, share similar motions during two time-intervals. The first one (615-590 Ma) can be described by rotation around an Euler pole located in the equator, while the second one (575-565 Ma) by another around an Euler pole on the tropics. Whether these apparent large and fast displacements can be assigned to IITPW events is discussed along with the consistency of considering a large Clymene Ocean during this time.
New constraints on the Neo-Tethyan carbon cycling and its forcing of early Cenozoic climate
Authors: Sternai Pietro , Castelltort Sébastien , Bouilhol Pierre , Vimpere Lucas , Ostorero Léa , Ali Mubashir , Castrogiovanni Luca , Vaes Bram , Garzanti Eduardo
Published: March 2024

Cenozoic climate trends are classically ascribed to variations of the geological carbon cycle related to Neo-Tethyan geodynamics. It is widely agreed that the collision of India and Arabia with Asia and associated mountain uplift enhanced erosion and global silicate weathering rates, ultimately driving post-50 Ma climate cooling. Cenozoic climate trends, however, involve major events of global warming in the early Paleogene (~60-50 Ma), a period that preceded rapid mountain uplift by about 30 Ma and that was characterized by a climax of arc magmatism profoundly affecting the surface CO2 budget and consequently climate. We present new measurements of mercury and carbon-isotope anomalies documented in the sedimentary archive, together with pre-eruptive CO2 budgets of Neo-Tethyan magmas encompassing the India-Asia and Arabia-Asia collision. We also show new forward modeling of the Neo-Tethyan geodynamics and inverse modeling of the Cenozoic surface CO2 budget which, tied to these new observational constraints, allow us to quantify magmatic CO2 emissions associated with the collision of India and Arabia with Eurasia. We demonstrate through such comprehensive and interdisciplinary approach that CO2 emissions associated with magmatic pulses induced by subduction of Neo-Tethyan lithosphere as well as of Indian and Arabian passive-continental-margin successions exerted a primary control on early Cenozoic climate changes.
Seismic Site Effects Assessment at the Illinois Basin–Decatur Project (IBDP) site
Authors: Semenova Yuliia , Vilarrasa Victor
Published: March 2024

Carbon capture and storage (CCS), is key to curtail carbon dioxide (CO2) atmospheric emissions and mitigate climate change. The complexities of carbon dioxide (CO2) storage are deeply intertwined with induced seismicity, a phenomenon set in motion by pore pressure, temperature and stress changes occurring during CO2 injection. If perceived, induced seismicity may negatively affect public perception of this carbon-removal technology. Here, we focus on assessing ground motion manifestations on the surface during hypothetical earthquakes with magnitudes ranging from 2 to 5, occurring at a depth of 2 km beneath the upper edge of the Precambrian basement rock of the Illinois Basin–Decatur Project (IBDP) site. The objective of this investigation is to analyze the seismic response of the IBDP site surface to earthquakes of specific magnitudes, considering their potential occurrence in connection with CO2 storage at the gigatonne scale.The analysis of ground motion manifestations on the surface during various earthquake scenarios of different magnitudes at the IBDP site provides valuable insights into the seismic vulnerability of the location. It allows for a comprehensive assessment of both amplification and attenuation effects, revealing how the geological and geotechnical characteristics of the subsurface rock influence ground motion. Understanding how the site responds to seismic events allows for a more accurate assessment of potential risks and vulnerabilities.Employing the equivalent linear approach of Ground Response Analysis, we computed the Fourier amplitude spectra of seismic motions on the surface of the IBDP site for earthquakes with magnitudes 2, 3, 4, and 5. These spectra are then compared with the Fourier amplitude spectra of input motions. The Fourier amplitude spectrum illuminates how ground motion amplitude is distributed across various frequencies. We also analyze the calculated Fourier Amplitude Ratio.Through a thorough comparison of these spectra, we explore the shifts in amplitude-frequency composition as the magnitude increases. This analysis is instrumental in identifying frequencies that gain prominence or diminish, revealing resonant frequencies and their correlation with input wave amplitude. These findings are crucial for understanding the dynamics of seismic events across different magnitudes and their environmental repercussions at the IBDP study site. Moreover, they have the potential to contribute to the optimization of practices in CCS.
Deterioration of Air Quality in Delhi due to Crop Residue Burning in the Agricultural State of North-Western India
Authors: Saxena Pallavi , Sonwani Saurabh , Srivastava Anju , Jain Madhavi
Published: March 2024

Crop residue burning (CRB) over Northern India is an alarming issue and leads to human health effects. The present study aims to study the impact of PM10, PM2.5, NO2 and SO2, emitted during CRB activities in the agricultural state of North-western India i.e. Haryana on the air quality of Delhi. The transition from pre-burning to burning period, in both rabi and kharif seasons, shows considerable increase in pollutant concentrations. PM10 and PM2.5 concentrations exceeded NAAQS limits by 2–3 times, while NO2 and SO2 stayed within the limits. MODIS fire observations used to estimate CRB fire counts (confidence >80%) shows that rabi (burning period) fires in Haryana are ~3 times higher and more intense than in kharif. Furthermore, backward trajectories shows air mass movement from Haryana, Punjab and Pakistan. Thus, pollutants emitted reach Delhi via air masses, deteriorating its air quality. Meteorological conditions influence pollutant concentrations during both seasons. Frequent dust storms in rabi, and Dusshera and Diwali firework celebrations in kharif season exacerbate air pollution. In rabi, PM10 and PM2.5 have a significant negative association with (relative humidity) RH and positive association with (air temperature) AT. High AT during pre-monsoon, accompanied by low RH, loosens up soil particles and they can easily disperse. Stronger winds in rabi season promote NO2 and SO2 dispersion. In kharif, lower AT, higher RH and slower winds exist. Both PM10 and PM2.5 have a negative association with AT and (wind speed) WS. With lower temperature and slower winds during winter, pollutants are trapped within the boundary layer and are unable to disperse. As expected, NO2 has a significant negative association with AT in Haryana. However, in case of Delhi, the association is significant but positive, and could be due to the odd-even scheme imposed by the Delhi government. Strong initiatives are needed to mitigate the ill-effects of CRB activities over the region, in both rabi and kharif season. Large-scale farmer awareness camps and the use of sustainable CRB management practices are suggested.
Pore-fluid pressure evolution across the blueschist-to-eclogite-facies transition:  constraints from the Eclogite Zone (Eastern Alps)
Authors: Strobl Leonie , Smye Andrew
Published: March 2024

Variations in pore fluid pressure modulate effective normal stresses along fault zones and the subducting interface. Fluid availability is controlled by the decomposition of hydrous mineral phases and the subsequent rate of drainage. Geophysical observations suggest that the plate interface is a fluid-enriched region under near-lithostatic pore fluid pressure that may result in slow slip events (SSE) and non-volcanic tremor (NVT). The potential for fluid redistribution depends on dynamic changes of the porosity and permeability of the host rock as a function of solid-bound fluid volume change and the total system volume change during dehydration. Understanding the mechanisms involved with the evolution of porosity and permeability below the seismic zone is critical to gain insight into the formation of fluid networks and their rheological implications.Here we present a petrological and mechanical analysis of the evolution of a suite of eclogite-facies veins from an archetypal HP-LT terrain: the Eclogite Zone, Eastern Alps. We define two dominant compositional types of mafic eclogite: banded and metagabbroic, respectively. Prograde metamorphic evolutions are similar for the two types of eclogites and comprise garnet core growth at 2.1 ± 0.25 GPa, 585 ± 15°C and rim equilibration at 2.6 ± 0.2 kbar, and 630 ± 10 °C. Contemporaneously to prograde garnet growth, the mafic eclogites underwent dehydration via the breakdown of several volumetrically significant hydrous phases: lawsonite, Na-amphibole (glaucophane), and epidote. The decomposition of lawsonite and glaucophane released up to 8 wt. % H2O, resulting in the formation of a transient fluid filled porosity of ∼ 15 vol. %.Phase equilibria calculations serve as a framework to constrain a mechanical model explaining the formation of both tensile fractures (type I) and vein segregates (type II) within the brittle-ductile transition zone. We propose a petrological-mechanical model for the formation of Type I tensile veins associated with periods of rapid dehydration and Type II dilatant structures in which rock deformation is outpaced by the reduction in pore fluid pressure, leading to a decrease in silica solubility and the precipitation of high-pressure mineral phases. Finally, this suggests that the rate of dehydration during the blueschist-eclogite transition plays a significant role in determining the dominant mode of deformation possibly affecting the fluid storage capacity of the subducting interface.
Effects of Upstream Obstacles on Energy Production of Solar and Wind Farms
Authors: Bhattacharya Abhirup , Baidya Roy Somnath
Published: March 2024

Power production from a renewable energy (RE) source such as a wind farm or urban roof-top solar panel installation is highly sensitive to the obstacles around it, particularly those which are in the upstream direction. RE installations can avoid or minimize the effects of obstacles using proper planning. However, obstacles that come up after the plant is operational can lead to significant loss in power production and revenue. In this study we quantitatively explore two common examples – shading effect of neighbouring buildings on roof-top solar plants and wake effects of upstream wind turbines on offshore wind farms.The first example considers a horizontal solar panel atop an urban building in a relatively congested neighbourhood. We built a model to quantify the shading effects of neighbouring tall buildings on the solar panel. The model calculates the position of the Sun on the celestial dome at every minute with astronomical accuracy. Then the solar irradiance is calculated for a clear-sky environment. After that the shadow profile is calculated and visualized for obstacle buildings with any height and at any distance. And finally, the loss in available insolation and the power production is calculated. The results show significant power loss due to the building shading effect. For example, a roof-top solar panel surrounded by a 20m taller building at 20m distance can reduce power generation by more than 50%.The second example is where a new wind farm is constructed upstream of an existing wind farm. We used two different models to quantify the meteorological effects of the upstream wind turbines on downwind turbines. The first one involves Jensen Wake Model (JWM), a static wake recovery model to simulate the wake effects of upstream obstacle turbine on downwind turbine. The second approach makes use of the Wind Turbine Parameterization (WTP) in WRF. This method implements wake loss using a wind turbine power curve data and wake recovery through atmospheric vertical mixing. A case study has been conducted for a hypothetical offshore wind farm situated in Palk Strait between India and Sri Lanka by placing wind farms of different shapes and dimensions in the upwind direction. The results show a range of losses in annual power production between 3 – 12 MW, which roughly converts into €1.1M – €4.1M.This study demonstrates that the effects of upstream obstacles on RE sources are non-trivial and can have serious impacts on the performance on RE installations. Currently, local zoning laws in India and many countries do not protect RE installations from future constructions that can act as obstacles. Hence, effective policies are required to safeguard the return on investments in the RE industry.
Insights into long-term variations of Black carbon over various metropolitans in Pakistan
Authors: Hina Saadia , Nisar Hamna , Tariq Salman , Ibrahim Muhammad , Habib Ammara
Published: March 2024

Black carbon (BC), despite their small contribution in atmospheric aerosol loads, have growing attention for air quality, human health, and climate change implications. This study aims to investigate the long- term spatio-temporal trends of BC over various metropolitan cities in Pakistan through MERRA-2 reanalysis datasets ranging from 2001 to 2022. In addition, statistically significant spatial clusters (hotspots) of BC in Pakistan have been assessed through a geospatial statistical tool (Getis-Ord 𝐺∗𝑖) and finally, the hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model has been applied to identify the path and direction of BC. The increased trend of BC has been observed in winters due to low PBH (planetary boundary layer) and increased anthropogenic activities during this season. The decreased trends of BC were observed in summers due to precipitation and the washout process. Among the metropolitans of Pakistan, the highest values of BC concentration were recorded in Karachi while lowest values have been observed in Islamabad. The findings showed that most of the hotspot regions are in the southern region along with some central areas. The results demonstrate that BC concentration in Pakistan rises annually because of increased biomass burning, vehicle emissions, and transboundary air pollution. It is anticipated that our study will furnish valuable insights for assessing the hotspots of BC along with their local and remote sources across Pakistan.
Understanding and managing growing drought risks – the need for a systemic perspective
Authors: Hagenlocher Michael , Naumann Gustavo , Meza Isabel , Blauhut Veit , Cotti Davide , Döll Petra , Ehlert Katrin , Gaupp Franziska , Van Loon Anne F. , Marengo Jose A. , Rossi Lauro , Sabino Siemons Anne-Sophie , Siebert Stefan , Tadege Tsehayu Abebe , Toreti Andrea , Tsegai Daniel , Vera Carolina , Vogt Jürgen , Wens Marthe
Published: March 2024

In the last few years, the world has experienced numerous extreme droughts with adverse impacts on coupled human and natural systems. While agriculture is the most affected sector, the lack of water due to droughts in our highly interconnected world also affects ecosystems, public water supply, power generation, tourism, water-borne transport and buildings, often with non-linear cascading and systemic impacts. Moreover, droughts also interact with other hazards in complex ways, for example leading to compound heat-drought events, wildfires or aggravated impacts when concurring with other non-climatic hazards and shocks, such as the COVID-19 pandemic. At the same time, responses to droughts can also lead to response risks, for example when the establishment of reservoirs in response to droughts leads to overreliance on these reservoirs and in turn increases the vulnerability of communities, sectors and systems to droughts. Combined, these characteristics pose a serious challenge to our ability to grasp the complexities of drought risks and to manage them in a comprehensive way. To avoid ineffective risk management and maladaptation, a paradigm shift in how we look at, assess and manage drought risks is urgently needed – from a siloed, single-risk (e.g. drought risks for agriculture, energy, transport) to a systemic perspective.  However, despite more frequent and severe events, systemic drought risk assessment is still incipient compared to that of other meteorological and climate hazards. This is mainly due to the outlined complexity of drought, the high level of uncertainties in its analysis, and the lack of community agreement on a common framework to tackle the problem. Addressing this gap, we propose a novel drought risk framework that highlights the systemic nature of drought risks, and show its operationalization using the example of the 2022 drought in Europe. Our research emphasizes that solutions to tackle growing drought risks should not only consider the underlying drivers of drought risks for different sectors, systems or regions, but also be based on an understanding of sector/system interdependencies, feedbacks, dynamics, compounding and concurring hazards, as well as possible tipping points and globally and/or regionally networked risks.
Climate change and sustainability resources: making materials from biomass
Authors: Zambrotta Maria
Published: March 2024

Can the 3Rs approach combat the escalating waste problem and the climate change? Are bio-based products the solution for a sustainable future? Through this project students will learn about bioeconomy, using their STEM skills and the results of the labs activities, they try to solve some challenges: to give new life to obsolete material. They were divided into working groups to explore the problem, develop labs activities and propose their ideas.Keratin from woolSheep’s wool has always been used as an agricultural product by pastoral communities, but in recent years, it went from agricultural product to waste. Shearing the flocks is an act that farmers must perform at least once a year to maintain the animal welfare, but as wool has diminished its economic power, it has become just a cost. In 2015 it has been calculated that around 200,000 tonnes of coarse wool are produced each year in Europe, the disposal of which is a problem. It is no longer possible to abandon the wool in the pastures or left to burn slowly, with the consequent release of toxic gases and carbon dioxide into the atmosphere. In recent years, to revalue the product and the market, there has been increasing academic and industrial research aimed at exploiting wool particles as textile materials, filtration adsorbents, cosmetic materials, and biomaterials.Wool fibers consist of 95%−98% proteins (about 80%−85% keratin), lipids (0.1%), and minerals (0.5%), using chemical and mechanical methods, it can be utilized as a natural source of keratin. The natural keratin can be used to produce a variety of cosmetics, creams, shampoos, hair conditioners and biomedical products. Several methods for keratin extraction and production of hydrolyzed keratin have been proposed in the scientific literature. They vary depending on the intended uses of the obtained product, whether for cosmetic, pharmaceutical, food use.The activity proposed to the students is to explore the wool economy and the chemical composition and to develop experimental activities to extracts  keratin from wool using a suitable extraction solution and use keratin to prepare cosmetics.Pectine from citrus peelPectin is yellowish, odorless powder soluble in pure water. It is an important cell wall polysaccharide that allows primary cell wall extension and plant growth. Pectin is used for different applications in dairy, confectionary, pharmaceutical and food and the industrial application of it is increasing.A factory producing flavor, near our school, proposed to the students the challenge to reuse the citrus peel coming from a strong extraction of essential oils. Students analysedd the composition of peel and proposed to extract pectin using HCl solution and precipitation with ethanol.ConclusionThe proposed activities fit a broader project on the valorization of waste. These are simple experiments that fail to exhaust the extensive literature related to the use of biomass from waste material but start from a material that is known to all and easy to find.
Approaching 1.5°C: What is the Current Global Warming Level?
Authors: Betts Richard , Belcher Stephen , Hermanson Leon , Klein Tank Albert , Lowe Jason , Jones Chris , Morice Colin , Rayner Nick , Scaife Adam , Stott Peter
Published: March 2024

It will be important to know when global warming has reached 1.5°C, as this will be a key marker in global policy given the ambition to pursue efforts to limit warming to this level. But how should the temperature increase be defined in this context? The Global Stocktake agreed at COP28 in Dubai noted “global warming of about 1.1 °C” based on the IPCC 6th Assessment Report, but this number applies to the average of 2011-2020 and hence is already out of date. We propose that the metric for current global warming should allow immediate of identification of passing particular levels of global warming, such as 1.5°C, to avoid unnecessary delays in responding to the exceedance. We also propose that the metric should be consistent with the definition of future Global Warming Levels in the IPCC 6th Assessment Report, which uses 20-year means of projected temperature anomalies with an exceedance year defined as the mid-point of the 20-year period. Without this consistency, the apparent time of reaching 1.5°C could differ from the time previously projected by the IPCC merely because of differences in the definition, which could be misinterpreted as indicting that global warming had reached 1.5°C either earlier or later than projected. This could either undermine confidence in projections or misinform discussions on action to address climate change.While various indicators are already in use that provide a more instantaneous measure of global warming, none are consistent with the IPCC definition of future GWLs nor are suitable for use as a baseline for impacts assessments. To address this, we propose a new metric, the Current Global Warming Level (CGWL), which uses a 20-year average over the previous 10 years from observations and the next 10 years from a forecast or projections. Here we compare the CGWL with the various indicators currently in use for quantifying the current level of global mean temperature change, and compare their indications of global temperature change over recent decades and of the current level of global warming. We also compare the year of exceeding past global warming levels of 0.5°C, 1.0°C and 1.2°C for each indicator. We use a combined observational dataset following IPCC methods and process the indicators from this. For each indicator, we explain potential difficulties that could arise from its use to assess when global warming reaches 1.5°C relative to pre-industrial, and explain the rationale for our proposed indicator, the Current Global Warming Level.
Characterizing auroral precipitation and ionospheric conductance with the Dragon King model in MAGE
Authors: Lin Dong , Bao Shanshan , Wang Wenbin , Merkin Viacheslav , Sorathia Kareem , Lotko William , Wang Dedong , Pham Kevin , Ma Qianli , Sotirelis Thomas , Shi Xueling , Michael Adam , Sciola Anthony , Wiltberger Michael , Toffoletto Frank , Lyon John , Garretson Jeffrey
Published: March 2024

Auroral precipitation plays an important role in the magnetosphere-ionosphere-thermosphere (MIT) coupling. Various precipitation spectra have been observed and they are driven by different physical mechanisms. In this study, we report the Dragon King model which is used to characterize auroral precipitation and its consequent ionospheric conductance in the Multiscale Atmosphere-Geospace Environment (MAGE) model, a newly developed whole geospace model. Mono-energetic electron precipitation is derived from large-scale field-aligned currents and drift-physics informed loss cone rate, using the linearized Fridman-Lemaire relation. Diffuse electron precipitation is derived with a drift-physics based ring current model, in which electron lifetime due to interactions with chorus and hiss waves is obtained with an empirical table and electron loss rate is informed by drift physics and IGRF magnetic field. Broadband electron precipitation is derived from a statistical relationship between field-aligned Alfvénic Poynting flux and the precipitation energy flux and number flux. The Dragon King model is validated from different perspectives with various observational data, including the statistical pattern during different categories of solar wind driving conditions, and along-trajectory comparison with satellite measurements. The Dragon King model is further used to understand the drivers of different precipitation and their relative importance with MAGE simulations.
Recent and near-term future changes in impacts-relevant seasonal hydroclimate in the world's Mediterranean climate regions
Authors: Seager Richard , Wu Yutian , Cherchi Annalisa , Simpson Isla , Osborn Timothy , Kushnir Yochanan , Lukovic Jelena , Liu Haibo , Nakamura Jennifer
Published: March 2024

Change over recent decades in the world's five Mediterranean Climate Regions (MCRs) of quantities of relevance to water resources, ecosystems and fire are examined for all seasons and placed in the context of changes in large-scale circulation. Near-term future projections are also presented.   It is concluded that, based upon agreement between observational data sets and modeling frameworks, there is strong evidence of radiatively-driven drying of the Chilean MCR in all seasons and southwest Australia in winter.  Observed drying trends in California in fall, southwest southern Africa in fall, the Pacific Northwest in summer and the Mediterranean in summer agree with radiatively-forced models but are not reproduced in a model that also includes historical sea surface temperature (SST) forcing, raising doubt about the human-origin of these trends. Observed drying in the Mediterranean in winter is stronger than can be accounted for by radiative forcing alone and is also outside the range of the SST-forced ensemble. It is shown that near surface vapor pressure deficit (VPD) is increasing almost everywhere but that, surprisingly, this is contributed to in the southern hemisphere subtropics to mid-latitudes by a decline in low level specific humidity.  The southern hemisphere drying, in terms of precipitation and specific humidity, is related to a poleward shift and strengthening of the westerlies with eddy-driven subsidence on the equatorward side. Model projections indicate continued drying of southern hemisphere MCRs in winter and spring, despite ozone recovery and year-round drying in the Mediterranean.  Projections for the North American MCR are uncertain, with a large contribution from internal variability, with the exception of drying in the Pacific Northwest in summer.  Overall the results indicate continued aridification of MCRs other than in North America with important implications for water resources, agriculture and ecosystems. 
Quantifying above-ground biomass, SOC and erosion using a new detailed crop pattern map including double and triple cropping in the Yangtze River basin using the PESERA model
Authors: Zhou Jichen , Baartman Jantiene , Ning Yinan , Carvalho Nunes João , Ma Lihua , Liu Xuejun
Published: March 2024

Soil erosion represents a primary threat to soil systems with adverse implications for ecosystem services, crop production, potable water, and carbon storage. While numerous studies have quantified the spatial distribution of Above-Ground Biomass (AGB), soil erosion, and Soil Organic Carbon (SOC) in the Yangtze River Basin (YRB) in China, limited attention has been given to assessing the contributions of different land use types and especially crop types to AGB, soil erosion, and SOC. In most studies, cropland is taken as a land use class, while detailed crop types and rotation patterns, and their effect on soil erosion and SOC, vary significantly. In this study, we used the Metronamica model to generate a detailed crop rotation and distribution map across the YRB and subsequently employed the PESERA model to simulate the spatial distribution of AGB, soil erosion, and SOC on a monthly basis. PESERA model simulations indicate an average soil erosion rate across the entire YRB of 7.7 t/ha/yr, with erosion hotspots concentrated in the Sichuan Basin and the central-southern regions. The southwestern region and western Sichuan show elevated levels of AGB and SOC, while the eastern plains display lower levels. Erosion rates are lowest in areas designated as artificial land, pasture and grassland, whereas cropland and fruit trees experience the highest erosion rates. In terms of crop types, the highest erosion rates and lowest AGB are observed in fallow and potato cultivation, while the lowest erosion rates and highest AGB are found in rice-wheat rotation fields. To the best of our knowledge, this is the first study including detailed crop types and patterns into account while evaluating their effect on relatively large scale (i.e. YRB). These findings can help to develop sustainable soil management and (cropping) conservation strategies.
The Linkage Evolution of Strike-Slip Faults with Normal Faults—Insights from Analogue Modelling at Various Oblique Extension.
Authors: Wang Yuheng , Yu Fusheng
Published: March 2024

Fault evolution is influenced by multiple factors, including the reactivation of pre-existing structures, stress transmission within ductile detachment layers, and the growth, interaction, and connection of newly formed fault segments. In the same stress field, displacement vectors of fault strikes, dip-slip vectors, and subtle fractures accommodate strain distributed everywhere. This study employs PIV analysis and model reconstruction to simulate oblique extensional fault systems formed at four different angles. Simulation modelling indicates that oblique extensional reactivation of pre-existing structures controls the linear arrangement of fault segments in the overlying strata. Arcuate faults can be classified into linear master fault segments controlled by pre-existing structures, curved splay faults in termination zones, and normal fault segments responding to regional stress fields. Along-strike displacement is regulated by linear segments within the master strike-slip fault, while progressive bending of splay faults, relay ramps' dislocation, and inclined displacements are regulated by relay ramps within the overlap zone. Small-angle (15°) oblique extension favours the formation of fault segments with distinct step-like features, leading to additional relay ramps. In contrast, high-angle (60°) oblique extension often results in the development of more continuous fault segments. As faults continuously evolve, new fault segments tend to deviate from the control of pre-existing structures, concentrating more on the development of planar and continuous master faults. Finally, we compared the established model with the transtensional fault system within the intraplate rift system in eastern China, demonstrating that the oblique extension angle controls the composite characteristics of the overlying strata faults.
Predicting Global Change impacts on streamflow dynamics using distributed hydrological modeling in a data-scarce nested tropical catchment in West Africa.
Authors: Agbenorhevi Albert Elikplim , Klaus Julian , Amekudzi Leonard Kofitse , Kelome Nelly Carine , Biney Ernest , Annan Ernestina
Published: March 2024

Currently, the global water cycle is experiencing radical shifts and the associated global water crisis requires rapid action by stakeholders to mitigate adverse impacts on both human populations and ecosystems. This urgency in action is driven by the combined effect of Climate Change and Land-use land cover change (LULCC) and the associated challenges in securing clean water sources. The Global Change from climate change is making water scarcity worse in places that are water-stressed, causing more competition and even conflicts over water resources. Addressing the global water crisis is especially challenging in the data-scarce region of the Global South where the status of hydrological processes and water availability is poorly constrained. Here, progress in hydrological predictions through robust hydrological models remains on top of the research agenda. General for the Global South, and particularly for West Africa, is the limited hydrological process understanding of tropical catchments with accelerating land cover change. The focus of the research study seeks to address the following research questions:•    How does climate change alter hydrological processes in tropical catchments and does this alter streamflow regimes across nested catchments? •    How does and what are the contribution of LULCC in spatial-temporal changes of streamflow in a nested catchment in addition to the alterations driven by climate change within a given West African region?To address the questions above, we will rely on data from the Pra River Basin in West Africa. In the present study, we employed Google Earth Engine (GEE) and Random Forest Classifier (RFC) to assess a time-series spatio-temporal land-use/cover change and change detection of the Pra River Basin for the period 2007 to 2023. Focusing on five (5) LULCC classifications has become crucial to the region's unregulated large and small-scale mining activities. The use of the Normalised Difference Water Index (NDWI), and Modified NDWI (MNDWI), was effective in extracting water surface areas for the change detection and pressure on the Pra River Basin and dealing with the overestimation phenomenon. We next integrate the processed LULCC into an eco-hydrological model that is validated against observed and reanalysed streamflow at different stations, soil moisture, and groundwater data. Future work will consist of estimating the impact analysis of Global Change on streamflow using an ecohydrological model that will be driven with the downscaled climate scenarios from CMIP6 and time-series land use change scenarios. This multifaceted approach is novel to the scientific understanding of water resource dynamics in the face of Global Change in tropical systems.
Empirical upscaling of OzFlux eddy covariance for accurate, high-resolution monitoring of terrestrial carbon and water fluxes in Australia.
Authors: Burton Chad , Renzullo Luigi , Rifai Sami , Van Dijk Albert
Published: March 2024

We discuss the development of high-resolution (1 km) estimates of terrestrial carbon and water fluxes over the Australian continent by empirical upscaling of a regional network of flux tower measurements (“AusEFlux” v1.1 https://zenodo.org/records/7947265). We detail our ensemble learning approach for estimating the per-pixel epistemic uncertainty in flux predictions.  Our investigations demonstrate that regional or continental upscaling has several advantages over global upscaling, including: the ability to use regionally derived covariable datasets tailored to the regional environmental context; reduced computational constraints allowing for higher-resolution predictions, thus reducing the impacts of sub-cell landscape heterogeneity; ameliorating spatial biases present in global datasets that often have a strong northern hemisphere bias; simpler interpretation of results due the reduced requirement to generalise across vastly different climates, ecosystem types, and plant functional traits; and increased relevance to local stakeholders.  We compare AusEFlux with estimates from nine other products that cover the three broad categories that define current methods for estimating the terrestrial carbon cycle. We argue that consiliences between datasets derived using different methodologies offer alternative value for assessing the quality of an upscaling product than any given cross-validation technique, especially where training datasets have spatial or temporal biases that are difficult to mitigate. Lastly, we discuss the benefits of regularly updating our upscaling product to arrive at a systematic monitoring of terrestrial carbon and water fluxes.
Decreased carbonate pump during the Oligocene-Miocene Transition: Regulating the oceanic buffering capacity
Authors: Ma Ruigang , Liu Chuanlian , Jin Xiaobo
Published: March 2024

The oceanic carbonate cycle plays a crucial role in buffering anthopogenic CO2 emmision by regulating the total alkalinity (TA) and dissolved inorganic carbon (DIC) in the seawater. There is a growing interest in comprehending the role of biogenic calcification, the carbonate (counter) pump. The Early Miocene glaciation is thought to be triggered by the declining pCO2 potentially through a threshold effect of ~400 ppm (Greenop et al., 2019), a level we are approaching today. The mechanism(s) behind the long-term pCO2 decline during this period is still an open question, with little discussion on fluctuations in the carbonate burial. We estimated the changes in volume and flux of pelagic carbonate, specifically using coccoliths (calcite scales produced by coccolithophores). Our investigation spanned the transition from the Paleogene to the Neogene (~27-20 Ma), using marine calcareous nannofossil ooze retrieved from the IODP Site U1501 and U1505 located in the western tropical Pacific Ocean. The circular-polarized light microscope is used to measure the thickness (and volume) of the coccolith crystals. Integrating the linear sedimentation rates, we estimated that coccolith carbonate burial varied between 2-8×104 mol·yr-1·km-2. Our result aligns with the modeled alkalinity removal through pelagic carbonate burial (van der Ploeg et al., 2019). Moreover, scanning electron microscope (SEM) observations revealed calcite carbonate dissolution effects in the water column, with ~5-30% of coccolith carbonate dissolving during sinking, releasing additional alkalinity to the sea-water. A negative correlation between Ks and bulk TOC suggests that the organic and inorganic carbon burial were decoupled during the studied period. While further constraints are needed to improve our estimation (e.g., considering assemblage changes in coccolith and planktonic foraminifera), we tentatively conclude that the decline in carbonate production together with the increased dissolution weakened the carbonate pump. As a result, enhanced buffering capacity of the ocean likely played a role in the drawdown of pCO2 from the Late Oligocene to the Early Miocene.
A comparison study of the impact of large Solar Energetic Particle events on the Moon and Mars 
Authors: Guo Jingnan , Zhang Jian , Liu Bailiang , Dobynde Mikhail
Published: March 2024

Human beings are considering going back to the Moon and eventually to Mars within the next decades. However, we are still facing one major hurdle ``space radiation'' which is a significant and unavoidable risk for crews' health, especially for long-term stays at future lunar or martian stations. In particular, sporadic solar energetic particles (SEPs) generated via extreme solar eruptions may enhance the lunar or martian surface radiation levels to potentially hazardous values. Recent lunar and martian surface and orbital radiation detectors have advanced our understanding of the radiation environment of both planetary bodies. We have used the state-of-the-art modeling appoaches to study the radiation environment of the Moon and Mars. In particular, we study and compare the potential radiation effects of historically large SEP events on the surface and subsurface of the Moon and Mars.
Detection of RO2 radicals and other products from oxidation of VOCs in PAM chamber with NH4+ ionization mass spectrometry 
Authors: Li Yang , Ma Xuefei , Lu Keding , Zhang Yuanhang
Published: March 2024

Organic peroxy radicals (RO2), derived from volatile organic compounds (VOCs) oxidation by hydroxyl radical (OH), ozone (O3), and nitrate radical (NO3) etc., play an important role in atmospheric chemistry. Direct measurements of speciated RO2 are challenging but necessary for understanding their atmospheric fate and impact. In this study, we introduce a newly developed Proton Transfer Reaction measurement method (PTR3-TOF) using NH4+ as the ion source to measure the multifunctional complex RO2 and related reactive oxidation products based on the principle of chemical ionization mass spectrometry (CIMS). We establish a calibration system that combines a home-built OH calibration source with various standard VOC gases, enabling to quantify both RO2 radicals and closed-shell species with a detection limit of about 1.6×107 molecule cm-3 (2σ, 60 s) and an uncertainty of 10%. This technique is first applied to study the gas-phase ozonolysis of cyclohexene in our laboratory, with experiments carried out using the O3 OFR mode in a PAM-OFR system under near-real atmosphere conditions. As a consequence, a total of 30 cyclohexene ozonolysis reaction products are detected in the first step of cyclohexene ozonolysis, including 9 types of RO2 radicals and 21 types of closed-shell species, with oxygen atoms ranging from 1 to 8. We also establish a mechanistic model for the first-generation products of ozonolysis of cyclohexene, and the simulation and measurement results agree within a factor of 2-3 for the respective formulas except for some differences in a few species.
Marginal currents induced by the interaction between Kuroshio, tide, and coastal topography off the northeastern coast of Taiwan
Authors: Tsai Yi-Chen , Lee Hung-Jen
Published: March 2024

The goal of the study around the Hoping Sea is to explore the causes of the southward mean current formation along the Hoping Coast, Hualien, using a three-dimensional general circulation model (MITgcm). Hoping Township is situated on the northeast coast of Taiwan, the offshore region by which the Kuroshio Current passes. Two current meter sites were deployed around this region, named CS (121.76507˚E, 24.29757˚N) to the south and CN (121.77197˚E, 24.32964˚N) to the north. A long-term observation analysis finds that the ocean current at CS usually flows northeastward, aligning with the direction or, at least, with the northeast component of the Kuroshio; on the contrary, a southward countercurrent along the Hoping coast appears at CN. In order to explore the cause of the characteristic flow field, the MITgcm model was used to simulate six different scenarios. The first two simulations of the MITgcm model were conducted solely with Kuroshio as a driving force and a realistic topographic, in which the model was executed under the Kuroshio mainstream nearshore and offshore cases, respectively. The results showed that the countercurrent exists in Yilan Bay but does not reach the Hoping Sea when the Kuroshio is the only driving force of the model. Subsequently, simulations were conducted based on the previous work, with a tidal generating force imposed on the model. Combining the Kuroshio and tides in the model, the southward countercurrent was not prominent when the mainstream of the Kuroshio was set to close the Hoping coast. However, when we moved the Kuroshio offshore, the simulated results showed that the model flow field was in good agreement with the in-situ data in all simulated cases. Further, to explore the influence of tides and topographic effects on the flow field, two ideal water-tank basins were designed to simplify the topography. One was a straight coastline, while the other was a coastline with a protruding headland in the model. The results showed that the currents during the ebb tides flow southward and adhere to the alongshore coast. The mean flow north of the headland flowed southward increasingly, but the northeastward mean flow south of the headland weakened slightly.
Climate variability outweighs influence of climate mean on summer precipitation extremes
Authors: Nordling Kalle , Samset Bjørn , Fahrenbach Nora
Published: March 2024

Climate change can involve changes in mean conditions, and in their variability on short to long timescales. But which of the two  is more important for our future climate?  We present a study indicating that for the number of extreme precipitation days, changes in climate variability dominate over  changes in the mean state. This analysis is based on three large ensemble simulations across three CMIP6 models (MPI-ESM1-2-LR, CanESM5, and ACCESS-ESM1-5). Here, we decompose the total changes in daily summer precipitation and daily maximum temperature into mean and variability components (standard deviation and skewness of the daily probability density functions).  Our key findings are that:1) Changes in climate variability (i.e., day-to-day variability of precipitation and changes in the precipitation distribution) have a more pronounced impact on extreme precipitation events than changes in the mean state. 2) In contrast, changes in the mean temperature state play a more dominant role in determining overall changes in daily temperature. These insights  are valuable for understanding the mechanisms driving extreme weather events and  highlight the need to consider daily variability changes in climate change impact assessments.