bluuebunny/crossref_metadata_2025 huggingface dataset:
On the current state of the development of the magneto-hydro-static extrapolation method
Authors: Zhu Xiaoshuai
Published: March 2024

Modeling the three-dimensional (3D) magnetic fields of the solar active region in multiple layers is very important. The main approach is to extrapolate the magnetic field from magnetograms measured in the photosphere. A basic assumption of the modeling in the past several decades was to completely neglect all plasma effects and to perform the so-called force-free field (FFF) extrapolations. While the force-free assumption is well justified in the solar corona, it is not the case in the photosphere and chromosphere. A magneto-hydro-static (MHS) equilibrium which takes into account plasma forces, such as pressure gradient and gravitational force, is considered to be more appropriate to describe the lower atmosphere and has been developing rapidly during the past several years. In this talk, I am going to review various MHS modeling methods, including tests of these methods with known reference models and applications to real data. Recent developments of the MHS modeling will also be presented.
Recursive analytical solution for nonequilibrium multispecies transport of decaying contaminants simultaneously coupled in both the dissolved and sorbed phases
Authors: Chen Jui-Sheng , Ho Yu-Chieh , Liang Ching-Ping , Suk Heejun , Nguyen Thu-Uyen , Liu Chen-Wuing
Published: March 2024

Few analytical or semi-analytical models simulating the transport of sequentially decaying reaction products affected by nonequilibrium sorption in the groundwater have been presented considering decay or degradation reaction occurring exclusively in the dissolved phase in the literature. However, the process of decay in the sorbed phase, which is important for the transport of decaying contaminants, has been neglected in previously developed analytical models. This study is thus designed to develop a novel semi-analytical model for simulating the multispecies transport of decaying contaminants subject to a nonequilibrium sorption process simultaneously coupled in both the dissolved and sorbed phases. For this purpose, a set of first-order reversible kinetic sorption reaction equations that respectively represent the nonequilibrium sorption processes between the dissolved and sorbed phases, are coupled to a set of advection-dispersion equations, to illustrate the decay process which occurs in both the dissolved and the sorbed phases. By including the decay in the sorbed phase both the parent sorbed concentration and daughter sorbed concentration coexist in a set of first-order reversible kinetic sorption reaction equations, which absolutely complicate the theoretical derivation of the analytical solution. Recursive analytical solutions are derived to account for the concentration distribution of arbitrary transformation products with the aid of the Laplace transform and generalized integral transform. The correctness of the solutions is confirmed through a comparison of our newly derived recursive analytical solution with an existing model which considers an equilibrium sorption process. The newly developed recursive analytical solution is then applied to investigate how the decay in the sorbed phase affects the nonequilibrium transport of a four-member radionuclide decay chain. The result clearly predicts a lower radioactivity concentration of the first nuclide (238Pu), with decay in the sorbed phase, than the simulated results obtained using a model without decay in the sorbed phase. For other daughter elements (234 U, 230 Th, 226 Ra) of the radionuclide decay chain, neglect of decay in the sorbed phase leads to overestimation of the radioactivity concentrations. The result of large differences found in dissolved radioactivity concentration between the decay and no decay in sorbed phase may alter the decision of health risk assessment in the performance of radioactive waste disposal site. The implication is that the decay reactions of contaminants in the sorbed phase are important mechanisms that should be taken into accounts for accurately simulating and assessing the nonequilibrium multispecies transport of decaying contaminants.
Main findings from Chinese team of the DFG-NSFC Sino-German AirChanges project
Authors: Zhang Hongliang , Sun Yele , Wang Hongli , Wang Peng
Published: March 2024

The DFG-NSFC project titled ”Air pollution over China and the unwanted effects of mitigation strategies” aims to understand why ozone is increasing in response to air pollution mitigation strategies. In the project, the established Sino-German collaboration of atmospheric scientists proposed to analyze the key factors that have driven surface ozone concentrations in response to the imposed emission control measures. After three-year hard work, the project is coming to an end and more than 10 papers were published supported by the project. This presentation aims to summarize the outcomes from the Chinese team, including Fudan University, Institute of Atmospheric Physics, Chinese Academy of Sciences, and Shanghai Academy of Environmental Sciences.
Carbonyl sulphide uptake by a terra firme forest in the central Amazon.
Authors: Jones Sam P. , Acosta Ricardo , Ferreira Rosaria R. , Cely Toro Iván Mauricio , Quaresma Dias-Junior Cléo , Wolff Stefan , Martins Giordane , Kesselmeier Jürgen , Trumbore Susan
Published: March 2024

Carbonyl sulphide has potential as a tracer of gross primary productivity. However, its use at the ecosystem scale requires us to understand something about its atmospheric transport and the distribution of sources and sinks within the environment of interest. Despite the importance of understanding the controls on carbon uptake and release by Amazonian forests, very little is known about the carbonyl sulphide cycle of widespread terra firme ecosystems. Here we report on carbonyl sulphide exchange estimated from concentration measurements of carbonyl sulphide at various heights, atmospheric conditions and net carbon dioxide exchange on an 80 m tower, and from soil flux chambers at the Amazon Tall Tower Observatory. The landscape surrounding the measurement site, 150 km north-east of the Brazilian city of Manaus, is typical of the central Amazon consisting of plateaus and steep valleys. Growing on highly weathered and well-drained Ferralsols, these plateaus are covered by old-growth, terra firme forests reaching 30 to 35 m in height. The region experiences relatively stable temperatures throughout the year, but pronounced seasonality in rainfall with a minimum in August and maximum in March. Atmospheric measurements suggest that the forest within the tower footprint is generally a net sink for carbonyl sulphide. However, fires likely represent a regionally significant source of carbonyl sulphide during the dry season. Net uptake of carbonyl sulphide is greater during the day than the night indicating a strong link to light control of stomatal opening. Estimating gross primary productivity from this uptake is complicated by transport dynamics and soil activity. The tall canopy and diurnal variations in atmospheric mixing, with overnight drawn down followed by entrainment of the upper atmosphere after dawn, means storage has a large influence on net exchange at sub-daily timescales. At longer timescales these exchanges appear to cancel out, simplifying the estimation of average uptake. Similarly, uptake of carbonyl sulphide by the soil represents a significant and variable proportion of the estimated net exchange that needs to be considered when estimating the contribution of photosynthesis.
Olivine faceting and water storage: A complex dynamic anisotropic sink
Authors: Muir Joshua
Published: March 2024

The faceting behaviour of olivine controls many properties on the grain surface such as diffusion and storage.  This behaviour and its effects are poorly understood due to the difficulty of examining them and the many controls that are on this paper.  In this talk I shall present a thermodynamic model of olivine faceting and how it is controlled by temperature, pressure, iron, grain size and water content.  In turn I shall discuss how this faceting then controls other important properties such as storage of water on the grain boundaries and how these are perhaps an overlooked sink in the Earth’s mantle.
The fractional Sinusoidal wavefront Model (fSwp) for time series displaying persistent stationary cycles
Authors: Kermarrec Gael , Maddanu Federico , Klos Anna , Proietti Tommaso
Published: March 2024

In the analysis of sub-annual climatological or geodetic time series such as tide gauges, precipitable water vapor, or GNSS vertical displacements time series but also temperatures or gases concentrations, seasonal cycles are often found to have a time-varying amplitude and phase.These time series are usually modelled with a deterministic approach that includes trend, annual, and semi-annual periodic components having constant amplitude and phase-lag. This approach can potentially lead to inadequate interpretations, such as an overestimation of Global Navigation Satellite System (GNSS) station velocity, up to masking important geophysical phenomena that are related to the amplitude variability and are important for deriving trustworthy interpretation for climate change assessment.We address that challenge by proposing a novel linear additive model called the fractional Sinusoidal Waveform process (fSWp), accounting for possible nonstationary cyclical long memory, a stochastic trend that can evolve over time and an additional serially correlated noise capturing the short-term variability. The model has a state space representation and makes use of the Kalman filter (KF). Suitable enhancements of the basic methodology enable handling data gaps, outliers, and offsets. We demonstrate our method using various climatological and geodetic time series to illustrate its potential to capture the time-varying stochastic seasonal signals.
From Stiff Equations to Deep Learning: Overcoming Challenges in Simulating Complex Atmospheric Aerosol Chemistry
Authors: Shrivastava Manish , Sharma Himanshu , Singh Balwinder
Published: March 2024

Fine particles in the atmosphere known as Secondary Organic Aerosols (SOA) have a considerable impact on the Earth's energy budget, as they interact with clouds and radiation. The formation of SOA is a complex process that involves various chemical reactions in the gas phase, aqueous aerosols, and clouds. This process is computationally expensive for three-dimensional chemical transport models, as it requires solving a stiff set of differential equations. Deep neural networks (DNNs) can be used to represent the nonlinear changes in the physical and chemical processes of aerosols. However, their use is limited due to several challenges such as generalizability, preservation of mass balance, simulating sparse model outputs, and maintaining physical constraints. To address these challenges, we have developed a physics-informed DNN approach that can simulate the complex physical and chemical formation processes of isoprene epoxydiol SOA (IEPOX-SOA) over the Amazon rainforest. The DNN is trained over a short period of 7 hours of simulated IEPOX-SOA over the entire atmospheric column using the Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem). The trained DNN is then embedded within WRF-Chem to replace the default solver of IEPOX-SOA formation, which is computationally expensive. The approach shows promise, as the trained DNN generalizes well and agrees with the default model simulation of the IEPOX-SOA mass concentrations and its size distribution over several days of simulations in both dry and wet seasons. Additionally, the computational expense of WRF-Chem is reduced by a factor of 2. The approach has the potential to be applied to other computationally expensive chemistry solvers in climate models, which could greatly speed up the models while maintaining complexity.
Spatial patterns and drivers of wildfire carbon emission since 2
Authors: Liu Zhihua
Published: March 2024

Between 2000 and 2020, global wildfires emitted approximately 7.32 billion metric tons of CO2, constituting about 18.5% of fossil fuel-related emissions. Despite a decrease in the global burned area, wildfire carbon emissions showed no significant trend. This is because carbon emission of forest fires is increasing, and thus compensates for the reduction in carbon emission from savanna fires. Forest fires is about 5% of global burned area but contribute roughly 20% (1.5 billion metric tons) of these emissions. Increases in forest fire carbon emissions, particularly in the northern high latitudes, are attributed to climate change and human activities. In recent years, the rise in extreme wildfire emissions affects over 40% of global vegetated lands, often linked to extreme fire weather conditions. Addressing this requires the development of advanced forest fire risk identification and prevention technologies.
South East Asia and Middle East Geologic Formation Databases with Visualizations on Plate Reconstructions
Authors: Mamallapalli ONeil , Datla Raju DSN , Hou Hongfei , Granier Bruno , Addula Nallapa Reddy , LeBlanc Jacques , Ogg James , Siddiqui Nusrat Kamal , Shafer Cecilia , Ogg Gabriele , Du Wen
Published: March 2024

In a successful collaboration with numerous regional experts on the stratigraphy of Southeast Asia and the Middle East, our international team developed cloud-based stratigraphic lexicons with graphical user-interfaces. These databases consist of the Indian Plate (indplex.geolex.org) of nearly 1000 onshore and offshore sedimentary and volcanic formations across India, Pakistan, Nepal, Bhutan, Sri Lanka, Bangladesh, and Myanmar, of southeast Asian regions (chinalex.geolex.org; thailex.geolex.org; vietlex.geolex.org; japanlex.geolex.org) with ca. 5000 formations as of January 2024), and of Middle East regions (mideastlex.geolex.org; qatarlex.geolex.org). The entries for each formation contain details on the succession of lithology, as well as the fossils present, age range, regional distribution and associated images. APIs enable easy access and integration with other applications. A comprehensive search system allows users to retrieve information on all geologic formations for a specific date or geologic stage from multiple databases. The cloud-based databases and websites can be explored through user-friendly map and stratigraphic-column interfaces generated from TimeScale Creator software.Regional extents of each formation in GeoJSON format enables visualization as facies-pattern-filled polygons projected onto three proposed plate reconstructions of its corresponding time interval; or as time slices of regional paleogeography. These lexicon systems will be interlinked to other stratigraphic and paleogeographic databases through the lUGS Deep-Time Digital Earth platform. This comprehensive approach allows one better comprehend deep-time dynamics and gain valuable insights into the evolution of the different regions of our planet Earth.
Centennial landslide risk evolution in Medellin, Colombia
Authors: Ozturk Ugur , Nieto Lopera Sara Manuela , Aristizabal Giraldo Edier Vicente
Published: March 2024

The metropolitan area of Medellin, Colombia, gradually expanded toward steep hillslopes due to the constraining rugged topography surrounding the city. Steeper hillslopes are more prone to landslides by default. When combined with inadequate planning due to high population pressure, the landslide risk in the city increases disproportionately. We analyzed the city's expansion in 18 time steps since 1770. In particular, we explored the empirical relation between urban growth and landslide occurrences. From 1976 to 2023, the city nearly duplicated its area, going from 56 km2 to 110 km2. We showed that gradually, steeper hillslopes were urbanized, especially since 1941, accompanied by a growing proportion of land in high landslide hazard zones. We also found that landslide activity predominantly occurred on the outskirts of the urban area at any given time, resulting in harm primarily to newly emerged neighbourhoods.Within the study period, in 2005, when areal images were available, we also categorized the metropolitan area into consolidated urbanization, i.e., compact regular mesh, compact irregular mesh, condominiums, and equipment; and unbound urbanization, i.e., level I: scarce urbanization, level II: road deficit/scattered urbanization, and level III: urbanization scattered around an axis. We assigned each category to variables such as hillslope angles, landslide hazards, and socioeconomic strata. Unbound urbanization was identified on steeper hillslopes, coinciding with poorer communities. Hence, we conclude that the persistent expansion of Medellin into landslide-prone areas poses a considerable threat to the population, especially those with limited opportunities in deprived neighbourhoods. By documenting the city's evolution in relation to landslide occurrences, we want to emphasize the pressing landslide risk to local and international policymakers.
Excitation and Propagation of Magnetosonic Waves in the Earth's Dipole Magnetic Field: 3D PIC Simulation
Authors: Sun Jicheng
Published: March 2024

Magnetosonic (MS) waves are common plasma waves in the Earth's magnetosphere. The self-consistent excitation of MS waves has been studied by 2D particle-in-cell simulations in the meridian and equatorial planes of a dipole magnetic field. However, the direction of wave propagation is artificially limited in the previous 2D simulations. Therefore, the 3D simulation of MS waves needs to be investigated. In this study, we investigate the excitation and evolution of MS waves in the Earth's dipole magnetic field based on a 3D general curvilinear particle-in-cell simulation. We find that the MS waves are excited primarily within 3° of the equator when the thermal velocity of the ring distribution is much less than the ring velocity of the ring distribution. These waves propagate along both the radial and azimuthal directions nearly perpendicular to the background magnetic field. In the linear stage, the growth rates of MS waves are almost equal in the radial and azimuthal directions. Compared with the waves propagating along the radial direction, the waves propagating along the azimuthal direction can grow for a longer time, resulting in a larger wave amplification in this direction after saturation. The simulation results provide a valuable insight to understand the self-consistent evolution of MS waves in the Earth's dipole magnetic field, and the findings are useful for understanding the plasma wave-particle interaction in the Earth's radiation belts.
A crustal magnetic field model of Mars with spherical harmonic degree up to 14
Authors: Tian Lin , Luo Hao
Published: March 2024

We develop a new crustal magnetic field model of Mars with spherical harmonic degree up to 140, which is based on orbiting measurements from Mars Global Surveyor (MGS), Mars Atmosphere and Volatile Evolution (MAVEN), and surface measurements from InSight and Zhurong. We follow the techniques from M14 model[Morschhauser et al., 2014] to inverse the spherical harmonic coefficients, including assigning different weights to the data of different sources, eliminating outliers with huber norm fitting, and employing the horizontal gradient of Bz component as L1 regularization term in the final model. It is found that our new model achieves the best spatial resolution ever before (~150 km). The unweighted misfits between our model and the MGS MPO, MGS AB/SPO and MAVEN are 8.0 nT, 9.9 nT, and 8.1 nT, respectively. Compared with the previous models, our model predictions are consistent with the surface measurements at InSight and Zhurong landing sites since the surface data are involved in the model inversion, which indicates the surface measurements are crucial to constrain the model downward continuation. The model characterizes the small-scale stratigraphic units on Mars, for example, the Lucus Planum, Apollinaris Patera, Hadriaca Patera, etc., contributing to the research of the structures of magnetic anomalies on Mars with different scales and the evolution of Martian dynamo.
Who cares about tree carbon allocation?
Authors: klein tamir
Published: March 2024

Most biological C resides in trees. Humans have been increasing atmospheric levels of CO2, exerting feedbacks on both humans and trees. Now humanity seeks for ways to increase C sequestration, and hence understanding tree C allocation is pivotal to all life on Earth. In 2015 we presented the first full description of tree C allocation dynamics that accounts for all C fluxes and pools in a tree. In the years that passed, we have been applying the mass balance and isotopic 13C labeling approaches to study tree C allocation in the field and greenhouse, at levels spanning from ecological to molecular. We have been advancing knowledge on tree C allocation to (I) more tree species, representing more functional groups. (II) more growing conditions, including heat, drought, and elevated CO2. (III) research focused on belowground allocation: root growth, exudation, transfer to mycorrhizal fungi and beyond. (IV) research focused on molecular mechanisms of C storage and carbohydrate management in specific tree tissues.Among the many recent findings, we showed that (1) about half of all assimilated C is respired back to the atmosphere, but variations between tree species are large. (2) in the Mediterranean, conifers allocate more C belowground than evergreen broadleaf species. (3) under drought, while C sequestration (source) decreases significantly, C sinks remain the same, but partition less to respiration and more belowground. (4) under drought and heat, C sinks rely on decomposition of C reserves such as starch. (5) under elevated CO2, C sequestration increases in proportion to CO2 level, but not tree growth. C allocation patterns change in a species-specific manner. (6) CO2 responses continue up until other minerals run out. (7) a lot of uncertainty revolves around belowground C allocation. Root growth dynamics measured in the field are distinctive from stem or leaf growth. (8) root exudation accounts for 10% of all assimilated C but is decoupled from assimilation dynamics. (9) C transfer to mycorrhizal fungi is more rapid and diverse than previously thought. (10) part of the mycorrhizal C finds its way to neighboring trees through the mycorrhizal network. (11) at the molecular level, daily starch metabolism gene expression is different from the stress-mode starch metabolism pattern, operating unique beta amylases and starch synthases. (12) many other gene families are involved in C allocation, e.g., vacuole hexose transports, which regulate glucose levels in leaf and stem cells. (13) overexpressing one of these transporter genes produced fast-growing mutant poplar trees.Taken together, these findings are crucial to all life on Earth, and particularly to us humans, at any level: scientists; stakeholders; and the wide public. Who cares about tree carbon allocation? Everybody!
Petrographic Heterogeneity and Sandstone Evolution in the Groningen Gas Field: Implications for Reservoir Geomechanics
Authors: Mulder Sebastian , Bublik Dmitry , Miocic Johannes
Published: March 2024

Fluid extraction from geological formations for purposes of subsurface utilization leads to pore pressure drop in reservoirs and subsequent compaction and seismicity, especially in porous sandstones. Petrography controls the geomechanical properties of the reservoir, crucial for predicting a reservoir's response to fluid extraction and understanding its lateral variability. This study focuses on the Groningen gas field in the Netherlands, addressing its compaction-induced surface subsidence and seismic events resulting from gas depletion. Core samples were examined to delineate spatial petrographic trends and develop a microscale model of the Groningen gas field. Optical microscopy (OM) and scanning electron microscopy (SEM) were used to determine mineralogical compositions, textural relationships and diagenetic processes. Predominantly constituted of sublitharenites, the sandstones exhibit dolomite and quartz cement as primary authigenic cements. Variations in clay types—kaolinite, illite, and chlorite—were observed, influencing localized pore-filling cementation processes.  Across the field, mineral relations revealed notable trends: depth-related feldspar decrease, correlation between kaolinite and feldspar abundance, and elevated chlorite content towards the northern sector together with the presence of an early quartz cementation phase, which is also observed within aquifer cores. The dissolution of feldspar potentially impacts the structural integrity of the sandstones, while authigenic mineralization appears intricately linked to depositional facies and localized fault-related fluid movements. The timing and extent of these diagenetic processes emerged as pivotal factors dictating sandstone stability within the reservoir. This comprehensive analysis enhances our understanding of Groningen's reservoir heterogeneity, offering critical insights to predict and manage subsurface responses to extraction-induced pressure changes. By providing predictive models, this study facilitates the evaluation of reservoir behavior and aids in mitigating risks associated with compaction-induced subsidence and seismicity.
Online databases of the geologic formations of Asia and Africa with display onto plate reconstructions
Authors: Ogg James , Du Wen , Sivathanu Aditya , Chang Sabrina , Mishra Suyash , Zahirovic Sabin , Ault Aaron , Mamallapalli O'Neil , Li Haipeng , Hou Mingcai , Ogg Gabriele
Published: March 2024

Building paleogeographic maps that are projected onto different tectonic plate reconstruction models requires team efforts to compile extensive interlinked databases of regional sedimentary and volcanic facies, data sharing standards, and computer projection methods. Two goals of the Deep-Time Digital Earth (DDE) program of the International Union of Geological Sciences (IUGS) Paleogeography Working Group are: (1) to interconnect online national databases for all geologic formations, and to compile these online "lexicons" for countries that currently lack these; (2) to project the combined paleogeographic output of these distributed databases for any time interval onto appropriate plate tectonic reconstructions.Therefore, we have worked with regional experts to compile and interlink cloud-based lexicons for different regions of the world that are enhanced by graphic user-interfaces. Online lexicons with map-based and stratigraphic-column navigation are currently completed for the Indian Plate (ca. 800 formations), China (ca. 3200), Vietnam-Thailand-Malaysia (ca. 600), and all major basins in Africa (ca. 700) and in the Middle East (ca. 700 formations). These will soon be joined by Japan (ca. 600 formations) and basins in South America (ca. 700 formations). A multi-database search system (age, region, lithology keywords, etc.) enables all returned entries be displayed by-age or in alphabetical order. The genera in the "fossil" field are auto-linked to their entries and images in the online Treatise of Invertebrate Paleontology. With a single click, a user can plot the original extent of the geologic formation (or an array of regional formations of a specified age) onto different plate reconstruction models with the polygon(s) filled with the appropriate lithologic facies pattern(s). Our team collaborated with the Macrostrat team at Univ. Wisconsin (Madison) to interlink with their extensive regional facies-time compilations for North America and the ocean basins to enable a near-global coverage. Following the lead of Macrostrat's ROCKD app, this project is in partnership with UNESCO's Commission for the Geologic Map of the World and other geological surveys to enable linking online geologic map units for direct access to the lexicon details on that geologic formation and its former paleogeographic setting. Essentially, goal is to create a view of the sediments and volcanics that were accumulating onto the Earth's surface at any time in the past.The main website (https://geolex.org) has links to the growing array of regional lexicons.
Multi-scale hybrid modeling of terrestrial evaporation
Authors: Koppa Akash , Baez-Villanueva Oscar , Bonte Olivier , G. Miralles Diego
Published: March 2024

Hybrid  modeling – combining physics with machine learning – in recent years has pushed the frontiers of Earth science, providing an opportunity to accurately characterize traditionally elusive variables. Terrestrial evaporation (E) is one such climatic variable which couples the global water and energy cycles. Accurately estimating E is important for determining crop water requirements at the local scale, while diagnosing the vegetation state at the global scale. Despite its importance, an accurate prediction of E has proven elusive, leading to the implementation of a plethora of mechanistic and data-driven models in the last few decades. The difficulty in modeling E can be traced to the complex response of transpiration (Et; i.e., evaporation from vegetation) to various environmental stressors, which are assumed to interact linearly in global models due to our limited knowledge based on local studies. Here, we train deep learning algorithms using eddy covariance and sap flow data together with satellite observations as inputs, aiming to retrieve a universal formulation of transpiration stress (St), i.e., the reduction of Et from its theoretical maximum. Then, we embed the new St formulation within the process-based Global Land Evaporation Amsterdam Model (GLEAM). In the resulting hybrid model, the St formulation is bidirectionally coupled to the host model at the daily timescale. Comparisons against in situ data and satellite-based proxies of E demonstrate the ability of this hybrid framework to produce better estimates of St and E globally across multiple spatial scales (ranging from 1km to 0.10 degrees) (Koppa et al. 2022). The proposed framework may be extended to improve not only the modeling of E in Earth System Models but also enhance the understanding of processes which modulate this crucial climatic variable. Future work in this direction involves the development of an end-to-end hybrid model, capable of simultaneously learning and inferring St and E through differentiable programming. Our results highlight the potential of combining mechanistic modeling with machine learning, especially deep learning, for improving our understanding of complex Earth system processes which are difficult to measure directly at the scale of interest.ReferencesKoppa, A., Rains, D., Hulsman, P. et al. A deep learning-based hybrid model of global terrestrial evaporation. Nat Commun 13, 1912 (2022). https://doi.org/10.1038/s41467-022-29543-7
The UFLUX ensemble of multiple-scale carbon, water, and energy fluxes.
Authors: Zhu Songyan , Xu Jian
Published: March 2024

In light of the challenges posed by climate change, global governments, including the United Kingdom (UK), have committed to addressing and mitigating the impacts of climate change, emphasizing the pursuit of Net Zero objectives. The terrestrial ecosystems on a global scale, functioning as pivotal carbon reservoirs, assume a critical role in climate change mitigation, especially within the context of an imminent scenario marked by accelerated warming and drying conditions. Recognizing that the carbon sequestration capacity of ecosystems is intricately linked to their energy and water cycling dynamics, this study presents the Uniform FLUXes (UFLUX)-ensemble dataset (https://sites.google.com/view/uflux) that accurately quantifies carbon, water, and energy fluxes across ecosystems in a consistent and mutually comparable manner. The UFLUX ensemble, relying on the upscaling of in-situ eddy covariance (EC) tower measurements using satellite vegetation proxies and meteorology reanalysis, constitutes the methodological foundation of this research.The UFLUX originated from our prior investigations into filling gaps in EC fluxes. This is due to the analogous nature of the procedures involved in flux gap-filling and upscaling, wherein both entail the interpolation/extrapolation of fluxes, albeit in the temporal and spatial domains, respectively. The fluxes in UFLUX are upscaled through the application of a uniform set of algorithms and environmental determinants, aiming to mitigate the sources of uncertainty. The UFLUX methodology has demonstrated effectiveness in capturing the global CO2 fertilization effect. Furthermore, it has exhibited resilience to agricultural management interventions and has adeptly captured flux variability at a high spatial resolution of 20 meters in southwest England. These accomplishments lay the groundwork for generating the UFLUX-ensemble dataset.The resulting UFLUX-ensemble dataset incorporates 60 members considering specific advantages of multiple satellite and meteorology reanalysis products. Aligned with the Net Zero vision articulated by nations, and recognizing the imperative of addressing data storage requirements, the dataset is made available on three scales: 1) daily 100-m resolution for the UK, 2) half-yearly 100-m resolution for Europe, and 3) monthly 0.25°×0.25°resolution for the entire globe. This diverse data provision is designed to assist climate actions, particularly in countries grappling with specific socio-economic challenges. A rigorous technical validation underscores the merits of the UFLUX ensemble, demonstrating its ability to capture 0.8 % of the flux variability with errors amounting to 0.76 g C m-2 d-1 and 11.67 W m-2. The UFLUX-ensemble dataset serves as a valuable resource, offering insights to inform land management practices, including nature-based solutions, with the overarching objective of augmenting carbon sequestration in terrestrial ecosystems and contributing to the realization of a carbon-neutral future.
Simulated net biospheric carbon emissions of managed peatlands, and implications for net-zero and net-zero targets.
Authors: Watts Alice , Roulet Nigel
Published: March 2024

Peatlands have been disturbed throughout the Anthropocene. Peatland extraction and peat use results in a significant net emission of greenhouses gases over a relatively short time frame. However, not all carbon in extracted peat is lost to the atmosphere. To understand net-zero emissions, it is important to understand how emissions can be mitigated through management practices, and what offsets are required for irreducible emissions. Our research has the aims: (1) to develop an environmental systems model based on previous research, introduce land use change and management phases to the model runs, and consider the implications of the fate of peat; and (2) to ascertain net biospheric carbon emissions according to model phases and their variations.The model approximates peat mass and accumulation in an undisturbed peatland system, then simulates the removal by extraction of horticulture peat.  The model replicates typical accumulation rates and measured emissions due to extraction. The environmental systems model has been coupled with a basic hydrological sub-model, and the model was evaluated by comparing simulated outputs to peat core 14C, C:N and FTIR field measurements from Riviere-du-Loup, Qc, Canada. We will present how management practices such as extraction duration, extraction intensity, and restoration delay impact simulated biospheric carbon emissions. Our simulations will also include the fate of extracted peat, demonstrating how peat use, storage and stabilised peat carbon impact net emissions. Based on our current restoration and extraction scenarios, we have deduced that it takes several thousand years to restore the biospheric carbon store of an extracted peatland. Preliminary work suggests that, depending on the assumed fate of the peat scenario, the biospheric restoration time can be reduced by 50-75% to recover carbon lost through peat extraction and use. Subsequently, offsets required for irreducible emissions to meet 2050 and 2100 targets can also be reduced.Our results will allow the Canadian peat industry to employ a backwards induction approach to meeting its net-zero targets by enabling us to infer when net-zero biospheric carbon emissions and carbon neutral conditions will be met without offset mechanisms and the duration with offset mechanisms.
Estimating the temperature at the core-mantle boundary from measurements of shear-wave velocity and seismic attenuation
Authors: Deschamps Frederic
Published: March 2024

The temperature at Earth’s core-mantle boundary (CMB) is a key parameter to understand the dynamics of our planet’s interior. However, it remains poorly known, with current estimate ranging from about 3000 K to 4500 K and more. Here, I introduce a new approach based on joint measurements of shear-wave velocity, VS, and quality factor, QS, in the lowermost mantle.  Lateral changes in both VS and QS above the CMB provide constraints on lateral temperature anomalies with respect to a reference temperature, Tref, defined as the average temperature in the layer immediately above the CMB. The request that, at a given location, temperature anomalies inferred independently from VS and QS should be equal gives a constraint on Tref. Correcting Tref for radial adiabatic and super-adiabatic increases in temperature gives an estimate of the CMB temperature, TCMB. This approach further relies on the presence of post-perovskite (pPv) phase in the deep mantle and on the fact that VS-anomalies are affected by the geographical distribution of phis phase. As a result, the inferred Tref is linked to the temperature TpPv at which the transition from bridgmanite to pPv occurs close to the CMB. A preliminary application to VS and QS measured beneath Central America and the Northern Pacific suggest that for TpPv = 3500 K, TCMB lies in the range 3470-3880 K with a 95 % likelihood. Additional measurements in various regions, together with a better knowledge of TpPv, are needed to determine a precise value of TCMB with this method.
Soil Moisture, Nutrients, Root Distribution, and Crop Combination Benefits at Different Water and Fertilizer Levels during the Crop Replacement Period in an Apple Intercropping System
Authors: Xiong Chang , Wang Ruoshui , Wang Xin , Wang Lisha , Chen Li , Dai Houshuai , Zhang Meng
Published: March 2024

Uneven soil moisture and nutrient distribution before and after intercropping limits apple cropping system productivity in the western Shanxi loess area. To address the problem, a field experiment was conducted between 2020 and 2021 to investigate the effects of different water and fertilizer management practices on soil moisture, nutrients, root distribution, and overall benefits of the intercropping system during the crop replacement period. The experimental set up included three factors: irrigation method, irrigation level, and fertilizer application; irrigation methods included drip (D) and flood (M) irrigation; irrigation levels included rain-fed without irrigation (W0), 50% of the field water holding capacity (Fc)-W1, and 80% of the field water holding capacity (Fc)-W2; fertilizer treatments included F0 (no additional fertilizer application), F1 (N 206.2 kg∙hm-2 + P2O5 84.4 kg∙hm-2 + K2O 84.4 kg∙hm-2), F2 (N 412.4 kg∙hm-2 + P2O5 168.8 kg∙hm-2 + K2O 168.8 kg∙hm-2), and control (CK) without irrigation and fertilization, for a total of 15 treatments. According to the results, soil water content (SWC) decreased after the crop replacement. Besides, nitrate nitrogen (NN), ammonium nitrogen (AN), and organic matter (OM) contents in all treatments increased, whereas total phosphorus (TP) content decreased. The main soil aggregate layer with crop roots shifted downwards (from the 0–40 cm soil layer before crop replacement to the 0–60 cm soil layer) after crop replacement, and partial fertilizer productivity (PFP), irrigation water use efficiency (IWUE), and water use efficiency (WUE) under both irrigation treatments were decreased. Principal component analysis showed that the W2F2 treatment had the highest combined benefits both irrigation treatments during the crop replacement period. Structural equation modeling showed that apple tree and maize RLDs had no significant effects on water use (ET) and WUE before crop replacement. Apple tree and soybean RLDs had significant positive correlations with ET and significant negative correlations with WUE after crop replacement. According to our results, to optimize the benefits of apple-crop intercropping, drip irrigation with complete water supply and flood irrigation with incomplete water supply are recommended during crop replacement. In addition, an upper irrigation limit of 80% of the field water holding capacity and a fertilizer application rate of N 412.4 kg∙hm-2 + P2O5 168.8 kg∙hm-2 + K2O 168.8 kg∙hm-2 are recommended for optimal water and fertilizer regulation.
Mangrove reforestation provides greater blue carbon benefit than afforestation for mitigating global climate change
Authors: Song Shanshan , Ding Yali , Li Wei , Meng Yuchen , Zhou Jian , Gou Ruikun , Zhang Conghe , Ye Shengbin , Saintilan Neil , Krauss Ken , Crooks Stephen , Lv Shuguo , Lin Guanghui
Published: March 2024

Significant efforts have been invested to restore mangrove forests worldwide through reforestation and afforestation. However, blue carbon benefit has not been compared between these two silvicultural pathways at the global scale. Here, we integrated results from direct field measurements of over 370 restoration sites around the world to show that mangrove reforestation (reestablishing mangroves where they previously colonized) had a greater carbon storage potential per hectare than afforestation (establishing mangroves where not previously mangrove). Greater carbon accumulation was mainly attributed to favorable intertidal positioning, higher nitrogen availability, and lower salinity at most reforestation sites. Reforestation of all physically feasible areas in the deforested mangrove regions of the world could promote the uptake of 671.5–688.8 Tg CO2-eq globally over a 40-year period, 60% more than afforesting the same global area on tidal flats (more marginal sites). Along with avoiding conflicts of habitat conversion, mangrove reforestation should be given priority when designing nature-based solutions for mitigating global climate change.
Advancing Landslide Monitoring in Tbilisi city and Imereti Region (Georgia): Integrating Tiltmeters, Piezometers, GPS and Geospatial Technologies
Authors: Koberidze Ramaz , Gaprindashvili George , Rikadze Zurab , Kurtsikidze Otar , Gaprindashvili Merab
Published: March 2024

This scientific exploration focuses on advancing landslide monitoring in the capital city of Tbilisi, Georgia and in Imereti Region village Gomi. By combining geotechnical monitoring systems, including tiltmeters and piezometers, with cutting-edge geospatial technologies such as digital elevation model (DEM) and aerial photography, our study aims to provide a comprehensive understanding of landslide dynamics in these diverse landscapes.The integration of tiltmeters and piezometers facilitates real-time monitoring of ground movements and pore pressure changes, offering valuable insights into the evolving geotechnical conditions. A robotic S9 Trimble apparatus is installed in the capital city of Tbilisi, which gives accurate movements level, as well as directions. Coupled with the analysis of digital elevation model and aerial photos, research explores the topographical and morphological factors influencing landslide susceptibility.The findings from Tbilisi and Gomi serve as case studies for urban and regional landslide hazard assessment. The study's strength lies in the integration of tiltmeters and piezometers, offering real-time monitoring of ground movement and groundwater fluctuations. Advanced geospatial technologies, such as satellite imagery and GIS, complement these measurements by providing a spatial context for landslide-prone areas. The combination of these methods enables a holistic approach to landslide risk assessment, considering the dynamic interplay of geological, climatic, and topographic factors.In conclusion, this research makes a valuable contribution to landslide risk assessment in Tbilisi and Imereti Region Gomi. By addressing the geographic, geological, and climatic nuances of the region and integrating tiltmeters, piezometers, and advanced geospatial technologies, the study enhances our understanding of landslide dynamics and supports the development of targeted risk mitigation strategies tailored to the unique conditions of this area.
Exploring Trappist-1d with a 3D GCM
Authors: Way Michael
Published: March 2024

Trappist-1d remains an underexplored planets in the fascinating multi-planet Trappist-1 system.Some earlier studies have indicated that it may be more of an exo-Venus than an exo-Earth [1,2].Of course atmospheric composition and density plays a key role and this parameter spacehas barely been explored. As well, since these earlier studies the insolation of 1d appearsto be almost 1% lower than earlier estimates [3,4]. A subsequent 1D study using thelower insolation [5] finds one atmospheric composition places it in the habitable zone,while the other in the Venus-Zone [6].  We use the ROCKE-3D General Circulation Model [7] to examine Trappist-1d's possible climate.[1] Wolf, E.T. (2017) ApJ 839:L1[2] Turbet et al. (2018) A&A 612, A86[3] Gillon et al. (2017) Nature 542, 456[4] Agol et al. (2021) PSJ 2:1[5] Meadows et al. (2023) PSJ 4:10[6] Kane, S.R. et al. (2021) AJ 161:53[7] Way, M.J. et al. (2017) ApJS 213:12
Modelling pathogen dispersal and distribution in estuarine systems under changing environment
Authors: Li Xiaorong , Robins Peter , Kevill Jessica , Malham Shelagh , Jones Davey
Published: March 2024

Treated and untreated wastewater enters estuaries via point source discharges, after which complex estuarine hydrodynamics can retain high concentrations of pathogens in these systems for days to weeks, posing a serious risk to public health. Through comprehensive fine scale three-dimensional numerical modelling, this research aims to study drivers of pathogen dispersal in estuaries and pathways of pathogen distribution. An interdisciplinary approach, combining knowledge from numerical modelling with laboratory derived data on pathogen behaviour and interactions with sediments, has been taken to improve the reliability of the model: 1) key fine-scale estuarine processes, i.e. current (including density current), turbulent mixing, and sediment transport have been studied using a process-based numerical model; 2) decay curves of target pathogens obtained through laboratory experiments for different water temperature, salinity, UV radiation have been implemented in the model; 3) the model also aims to incorporate pathogen attachment to sediments, their deposition, resuspension and subsequently altered decay rates.The Conwy estuary in North Wales, UK, has been used as our case study. The estuary holds considerable historical and contemporary significance in terms of shellfishery and tourism. With a catchment area of 678 km2 supporting a population of ~80,000 and large pastures, the estuary is susceptible to a range of pathogens, posing a public health risk via ingestion of bathing waters and indirectly via sea food.  The transport of pathogens from point sources, including wastewater discharge and sewage overflow, into the coastal environment has been studied under both current and future climate conditions such as sea level rise, warmer coastal waters, stronger river flow and population growth drawn from climate projections. As a further aspect of this research, conceptual estuarine systems will also be used to study fate and transport of pathogens under common estuarine dynamics and under representative climate scenarios.  This integration will allow for a more holistic approach that widens the applicability of the findings.This research will provide improved understanding of pathogen dispersal in coastal waters and the impact of climate change on pathogen distribution and potential exposure to humans. It will also provide insights for the development of adaptation strategies to protect public health under changing environmental conditions.