bluuebunny/crossref_metadata_2025 huggingface dataset:
Live monitoring, diagnostics and data management for the ACCESS suite of Earth-system simulations.
Authors: Tetley Michael , Squire Dougal , Beucher Romain
Published: March 2024

As global Earth-System simulations rapidly increase in complexity as a direct result of available compute resources and advancing scientific model development, monitoring long-running models and managing associated big data outputs has become increasingly difficult. This has inspired a need for open community-focussed software tools that provide intuitive and efficient HPC-native functionality to accurately evaluate live model performance and behaviour, perform diagnostic scientific analyses, compare current results with alternative or reference models, and generate standardised data outputs. Addressing these challenges, we present a new community-driven open-source project Model Live Diagnostics (MLD) which integrates the ACCESS-NRI Intake Catalog API, together forming part of The Australian Earth-System Simulator (ACCESS-NRI) Model Evaluation and Diagnostics (MED) framework supporting climate science research within the Australian Community Climate and Earth System Simulator (ACCESS). MLD is an open-source Python package optimised for use in JupyterLab sessions on the Australian NCI supercomputer Gadi. The primary purpose of MLD is to provide a simple, easy to use and accessible framework for the ACCESS modelling community to check, monitor, visualise and evaluate live running Earth-System model behaviour and progress. Utilising the ACCESS-NRI Intake Catalog API, MLD monitors a given model output data directory on Gadi, dynamically building an intake cataog of the most up-to-date data and automatically generating interactive plots to visualise model variables. From these data, MLD provides functions to perform light-weight diagnostic calculations, compare and plot results against reference models, and export data in standard Xarray format for integration into user workflows. MLD can be installed manually via Conda or PyPI, it comes pre-installed in existing Conda environments on Gadi, and the full source code is available on the project Github repository. MLD currently supports Earth System Model 1.5 (ACCESS-ESM1.5), Model for Ocean/Sea Ice (ACCESS-OM2) and Coupled Model 2 (ACCESS-CM2).
Hydrogeochemical Modeling of Opalinus Clay: Insights from CO2 Injection Experiments at Mont Terri Rock Laboratory
Authors: Koç Ümit , Corvisier Jérôme , Bruel Dominique , Blanco Martin Laura
Published: March 2024

Within the context of CO2 injection, understanding the properties of potential caprocks, particularly clay-rich ones such as Opalinus Clay and their potential evolution is crucial for safe and effective carbon capture and storage (CCS) initiatives. This study presents hydrogeochemical models developed to investigate interactions between groundwater, Opalinus Clay caprock and CO2, focusing on chemical evolution under varying pCO2 levels across different layers of the clay.Utilizing a comprehensive dataset derived from CO2 injection experiments conducted at the Mont Terri Rock Laboratory and published pore water chemistry of Opalinus Clay, hydrogeochemical models of a potential reservoir and caprock system were constructed employing PHREEQC and CHESS geochemical modeling softwares. These models were designed to simulate and comprehend the intricate processes governing groundwater-CO2-rock interaction within the reservoir-caprock interface and through the stratified layers of Opalinus Clay.The models aimed to elucidate the chemical evolution of the groundwater as it interacts with the Opalinus Clay under different pCO2 conditions. By considering variations in pCO2 levels representative of potential CCS scenarios, the simulations provided insights into the geochemical alterations occurring within the caprock and their implications for its integrity over time.The findings of these hydrogeochemical models offer valuable insights into the potential consequences of CO2 injection into reservoirs whose caprocks are formed of Opalinus Clay, informing risk assessment and mitigation strategies for CCS applications. Moreover, these constructed hydrogeochemical models not only serve as a crucial foundation for comprehending the intricate thermal-hydro-mechanical-chemical (THMC) coupling mechanisms within caprocks like Opalinus Clay but also contribute to a deeper understanding of the complex interplay between pore water chemistry, rock properties, and varying pCO2 levels, essential for ensuring the long-term security and effectiveness of subsurface CO2 storage.
Attributing the influence of climate change on the 2022 Pakistan floods 
Authors: Cotterill Daniel , Mitchell Dann , Stott Peter , Bates Paul , Leach Nicholas
Published: March 2024

In 2022 large parts of Pakistan suffered devastating flooding, with the southern provinces of Balochistan and Sindh particularly badly impacted. These regions received record-breaking rainfall totals during August, following a very wet July over the summer monsoon season. In this attribution study we combine the forecasting attribution technique developed by Leach et al. 2021 with flood inundation modelling to estimate the influence of anthropogenic climate change on the 2022 floods. This combined storyline and probabilistic approach uses the European Centre for Medium-Range Weather Forecasts (ECMWF) forecasts, and perturbed counterfactual forecasts with the same synoptic setup. These are fed into the 2D hydrodynamic flood inundation model LISFLOOD-FP over the worst affected regions to produce flood maps at 90m resolution.
Comparison of changes in quasi-biweekly oscillation intensity over the western North Pacific during the developing late-summer of super El Niño events
Authors: Xu Zhiqing , Fan Ke
Published: March 2024

This study investigated the differences in the changes in the quasi-biweekly oscillation (QBWO) intensity over the western North Pacific during the developing late-summer (1982, 1997 and 2015) of three super El Niño events and the possible reasons. The late-summer QBWO intensity was enhanced in these three years and the enhanced QBWO intensity in 2015, which was the strongest during 1980–2017, was remarkably stronger than that in 1982 and 1997. This mainly resulted from the differences in the anomalous late-summer background atmospheric conditions over the northwestern tropical Pacific, which were further modulated by the differences in the sea surface temperature anomalies in the Pacific. While strong warming appeared in the central and eastern equatorial Pacific (CEEP) in these three years, the warming and its center extended further west in 2015. More importantly, the warming in the central and eastern North Pacific (CENP) in 2015 was the strongest during 1980–2017, whereas there was cooling in 1982 and moderate warming in 1997. In 2015, the strong and westward-extended warming in the CEEP and the strongest warming in the CENP led to the strongest increased lower-level moisture and anomalous easterly vertical shear over the northwestern tropical Pacific during 1980–2017, favoring the strongest QBWO intensity. Numerical experiments confirmed the role of warming in the CENP in 2015. Besides, the frequency of extreme precipitation events over southern China during the late-summer of 2015 was the maximum of 1980–2017 and was closely related to the enhanced QBWO intensity over the western North Pacific.
Modelling the acceleration of radiation belt electrons to ultra-relativistic energies during a geomagnetic storm using VERB-4D
Authors: Haas Bernhard , Shprits Yuri , Wang Dedong
Published: March 2024

The most energetic electrons exceeding energies of 7 MeV are observed in the Earth’s outer radiation belt. In the past, numerical models of the radiation belts fell short to reproduce the acceleration to these ultra-relativistic energies, while the main acceleration process remains a debated topic.In this work, we use the VERB-4D (Versatile Electron Radiation Belt) model to examine a geomagnetic storm that occurred on April 20th, 2017 to investigate the acceleration of electrons to ultra-relativistic energies. Using the observations from NASA’s Van Allen Probes spacecraft and quasi-linear plasma theory, we show that such acceleration is achievable only under extremely low plasma density conditions. The full 3-D simulation with a statistical model of plasma density fails to reproduce the acceleration to such high energies, whereas the simulation with plasma density variations taken from observations successfully reproduces the observed energization to ultra-relativistic energies at all radial location.This study demonstrates the intricate interplay between the cold plasma and the acceleration of electrons to ultra-relativistic energies, and showcases our improved understanding of the high energy particle population.
Investigating the influence of natural and artificial thermal maturation on sedimentary mercury (Hg)
Authors: Indraswari Asri O. , Frieling Joost , Mather Tamsin A. , Dickson Alexander J. , Idiz Erdem , Jenkyns Hugh C. , Robinson Stuart
Published: March 2024

In recent decades, enrichment of mercury (Hg) in sedimentary deposits has been widely used as a proxy for volcanism from Large Igneous Provinces (LIPs). Mercury is naturally released into the atmosphere through volcanic exhalations and other processes, then dispersed and sequestered in sediments. Recent studies have delved into the impact of extremely high-temperature exposure on Hg in sediments, such as intrusion and contact metamorphism. However, the behaviour of sedimentary Hg exposed to more moderate warming, such as associated with thermal maturation and hydrocarbon formation in a sedimentary basin is still underexplored.We conducted a series of artificial maturation experiments on immature organic-rich marine mudrocks, specifically the Posidonienschiefer or Posidonia Shale (Lower Jurassic) in the Lower Saxony Basin, Germany. These pyrolysis experiments enabled us to investigate the changes in Hg concentration within rock residues and evolved organic fluids across varying maturation stages.Our findings reveal a progressive decline in Hg concentrations in sediments with increasing thermal maturity throughout the experiments (24 hours to 5 weeks at 325 ºC). Notably, the most significant Hg concentration loss occurs between the time-steps 5 days and 15 days. However, the substantial Hg loss from the pyrolysis experiments strongly differs from observations from naturally matured Posidonia Shale. In contrast to the slight decrease observed in the pyrolysis experiments, we recorded a trend of increasing Hg concentrations associated with higher maturity on three Posidonia Shale cores., We explore the mechanisms for these striking differences between the experimental and natural maturation and how these effects may have controlled Hg mobility during hydrocarbon formation and impacted the use of sedimentary Hg as a proxy for LIP-related volcanism.
Mapping glacial sediment plumes in the Antarctic Peninsula using deep learning
Authors: Wallis Benjamin , Hogg Anna , Hogg David
Published: March 2024

The subglacial discharge of sediment-rich meltwater plumes can be detected in satellite imagery where plumes reach the ocean surface at the terminus of tidewater glaciers. These meltwater plumes can influence glacier melting and ocean properties in important ways. Studying them provides insights into meltwater pathways in glacial hydrological systems.Sediment-rich meltwater plumes are observed extensively in Greenland, Svalbard and other regions, however in Antarctica observations have been more limited. Recent detections of seasonal speed variations on tidewater glaciers of the Antarctic Peninsula suggest that surface meltwater reaching the glacier bed may be an important factor influencing ice dynamic behaviour on the Antarctic Peninsula Ice Sheet (APIS), however surface-bed hydrological connections have not been directly observed through fieldwork on the mainland APIS. Therefore, studying the presence and distribution of sediment plumes around the Peninsula can provide insights to understand the factors influencing newly observed seasonal ice speed fluctuations.Here we develop a remote-sensing approach to map the locations and frequency of sediment plumes on the Antarctic Peninsula coastline using high-resolution multi-spectral imaging from Sentinel-2 satellites and a U-Net based convolutional neural network. This methodology allows us to detect small sediment plumes in images with high cloud and sea-ice densities. We apply our approach to the Antarctic Peninsula north of 65°S, including the South Shetland Islands, to produce a time-series of sediment plumes from 2016 to 2023 covering 150,000 km2.We use these results combined with outputs from regional climate models and reanalysis to assess the link between surface-visible sediment plumes and surface melt and runoff from the Antarctic Peninsula’s glaciers. We find that the timings and locations of sediment plumes correspond to modelled runoff, providing evidence for widespread surface-bed hydrological connections in the Antarctic Peninsula.
Solar energy, the types of energy that arise from it, and how we can use this energy while preserving the environment from pollution and preserving the natural ecosystem.
Authors: Kaçi Lorena
Published: March 2024

Our planet's changing climate is a diverse topic that allows students to brainstorm, discuss, and think about the best ways to protect our planet Earth. This project will be created by students in the seventh grade, age 12-13.Solar energy is the main source of life found on Earth. My  students and I will work together to develop a project based on solar energy, the types of energy that arise from it, and finally how we can use this energy while preserving the environment from pollution and preserving the natural ecosystem.Open discussion: Solar energy and how we can use it in our lives without harming our planet.Students will explain why food energy comes from the Sun.We will deal with the process of photosynthesis. Thanks to this process, plants receive energy from the Sun in orderto grow. The students will accompany this information with a graph where they show that the Sun is a source of energy for the plants and animals that we eat.We will talk about the importance of vegetation in our lives. For a planet to be as green and forested as possible as well as a rich atmosphere full of oxygen.We will use and discuss the Sun as a fuel energy source. Students will learn how biofuels and fossil fuels are created.A discussion on the benefits and negative consequences that have come as a result of their use by mankind.We will prepare sensitizing inform posters which we will stick around the city to make people aware of environmental protection and that changes will start with us. We will discuss the greenhouse effect, how we can help reduce the greenhouse effect, and how to regulate the climate on Earth.Wind and water energy and their importance in human life.Students will explain how wind and rain are formed thanks to solar energy. Students will answer the question: How can we use these energies for the benefit of humanity without harming the environment? They will give different ideas. These ideas will be illustrated with examples from everyday life. They will describe several methods of producing electricity from wind and water energy.Students will also collect information on the use of solar energy directly. Discussion on solar panels and the benefits of their use. Assess the importance of using solar panels by evaluating the preservation of the environment from pollution as well as the preservation of the natural ecosystem.We will visit a complex where solar panels are installed. Students will observe the construction of a solar panel. They will discuss with each other their construction, parts, and energy conversions in the solar panel. The tools for building the solar panel model will be prepared. Open discussion: How a solar panel is built. Students will bring the materials for the construction of the solar panel and will receive information about the types of panels, their use and purpose, and their advantages. They will build their own solar panel.
How accurately does gross primary productivity derived from remote sensing-based models represent the products from field measurements? Case studies of tropical vegetation in Borneo, Southeast Asia
Authors: Ginting Yohanes Risky Shellen , Esters Leonie
Published: March 2024

The total quantity of carbon fixed by photosynthesis per unit time in an ecosystem is referred to as gross primary productivity (GPP). This is an important activity in the Earth’s carbon cycle. In near-equilibrium conditions, GPP is calculated as the sum of net carbon exchange during the day plus ecosystem respiration. In our study, we compared the GPP from satellite-based model estimates with the actual GPP calculated by the eddy covariance method available from the FLUXNET database in Borneo, Southeast Asia. We found that the GPP models were unable to capture the actual daily fluctuations of GPP in tropical vegetation in Borneo, although there were moderate correlations when comparing GPP from two different remote sensing models (e.g. the GPP derived from the Vegetation Photosynthesis Model (VPM) has a moderate correlation with GPP products from Moderate Resolution Imaging Spectroradiometer (MODIS) Terra/Aqua for Maludam tropical peat swamp forest vegetation). Parameterization was required to improve the GPP models, which included reanalyzing each model parameter. These parameter include LUI (light use efficiency), which is a challenging model parameter to measure but is critical in determining GPP, and cloud cover on MODIS satellite data, which determines the quality of remote sensing indices such as LSWI (land surface water index), due to the importance of this index as a proxy for Wscalar to estimate VPM GPP.
Centrifugal pumps energy efficiency examining influential parameters contribution
Authors: Kordmahin Mohammad , Ebrahimghorbani Shima
Published: March 2024

Energy consumption around the world is the one the most important topics that researches and industrial sector make great effort to improve mechanical systems efficiency. Currently, energy efficiency enhancement strategies are widely applied all around the world as the crucial approaches to improve energy consumption. Pumps and air conditioning systems have remarkable contribution to the world electricity consumption that in the meantime pumps accounts for nearly 21% total consumption. According to the conducted literature, the level of the design accuracy in particular impeller as the heart of the pump, coupling system, electromotor and pump compatibility considering the operating conditions and piping system, and applied manufacturing processes as well as constructions materials. Simulation and modeling system can highly be an effective approach in early steps of design to examine whole system to be prepared for any circumstance. Even well-designed pump could work under bed operating conditions. This paper aims to provide insight into advanced characteristic modeling methods, and energy efficiency enhancement regulation to improve pumping systems. A comprehensive summary of traditional methods and advanced regulation methods have been proposed to shed lights on the relevant issues for future research.
Observed Increases in North Atlantic Tropical Cyclone Peak Intensification Rates
Authors: Garner Andra
Published: March 2024

Quickly intensifying tropical cyclones (TCs) are exceptionally hazardous for Atlantic coastlines.  An analysis of observed maximum changes in wind speed for Atlantic TCs from 1971-2020 indicates that TC intensification rates have already changed as anthropogenic greenhouse gas emissions have warmed the planet and oceans.  Mean maximum TC intensification rates are up to 28.7% greater in a modern era (2001-2020) compared to a historical era (1971-1990).  In the modern era, it is about as likely for TCs to intensify by at least 50 kts in 24 hours, and more likely for TCs to intensify by at least 20 kts within 24 hours than it was for TCs to intensify by these amounts in 36 hours in the historical era.  Finally, the number of TCs that intensify from a Category 1 hurricane (or weaker) into a major hurricane within 36 hours has more than doubled in the modern era relative to the historical era.  Significance tests suggest that it would have been statistically impossible to observe the number of TCs that intensified in this way during the modern era if rates of intensification had not changed from the historical era.    
Cryosphere-groundwater connectivity in the mountain water cycle - where does meltwater go?
Authors: Van Tiel Marit , Aubry-Wake Caroline , Somers Lauren ,   Mountain cryosphere-groundwater interactions working group
Published: March 2024

Both the mountain cryosphere -- comprising glaciers, snow, and permafrost -- and groundwater play crucial roles in shaping the hydrological cycle. However, their connectivity is not well understood. Understanding the importance of sub-surface meltwater flowpaths and the role of groundwater in mountain regions is critical to untangle 1) the fate of meltwater in the hydrological cycle and 2) the sensitivity of groundwater to a changing meltwater supply due to climate change.Here, we synthesize studies which investigated the dynamics of meltwater flow through mountain aquifers. In general, snow-groundwater connectivity is better described than glacier-groundwater connectivity. However, estimations of meltwater recharge fluxes vary considerably across studies, which is not only a function of inherent catchment characteristics but also of the different methods used for the assessments. Estimates of the source contributions of mountain groundwater range between 2-60% for glacier melt and between 40-80% for snowmelt. These large numbers suggest that cryosphere-groundwater connectivity and the consequent delay in meltwater flow needs to be part of our conceptual understanding of the mountain water cycle. Still, there is a clear lack of understanding at which spatio-temporal scales this connection operates.As glaciers retreat and snowpack diminishes, the relative importance of groundwater as catchment storage is expected to increase. This increase may however be partly compromised by declining recharge from the mountain cryosphere and changed recharge dynamics, with yet unknown effects on catchment-scale hydrological processes. We suggest a roadmap for future work to better quantify mountain cryosphere-groundwater connectivity and to predict climate change impacts on mountain water supplies.
Assessing river corridor changes after anthropogenic vegetation removal: an object-based mapping approach
Authors: Pavlek Katarina , Gašparović Mateo , Poeppl Ronald E.
Published: March 2024

The development of remote sensing technologies and image classification methods has facilitated research on changes in river channels and floodplains by automating mapping of land cover and geomorphic units. In often highly heterogeneous river environments, object-based approaches proved sensible, since they are based on objects produced by image segmentation rather than on individual pixels.This study uses object-based image analysis to investigate land cover and river channel dynamics in the managed corridor of the Orljava River in the Pannonian basin (Croatia). In the last decade, the river has been affected by anthropogenic removal of riparian vegetation to increase channel capacity, which was followed by a big flood event. Five river corridor classes (water, bare soil, sparse vegetation, dense vegetation, and shadows) were classified based on RGB and near-infrared (NIR) aerial images in the period 2011-2021. A digital surface model generated from the images was used to separate bare river channel units (“river sediments”) from bare soil in the floodplain and to define high vegetation, while agricultural land was classified manually. The accuracy of the produced maps was between 85 and 93%, except for the year 2014 which lacked the NIR band. Based on classified river corridor units, changes in channel morphology were further analysed in GIS. The two main phases of river corridor changes were caused by the occurrence of a big flood in 2014. In 2011-2014, immediately after the flood, a significant increase in the area of water and river sediments was recorded, mostly at the expense of bare riverbanks and adjacent agricultural land. Large in-channel bars have formed due to sediment accumulation, as well as significant channel migration has been recorded. Contrarily, in 2014-2021 lower discharges allowed gradual channel narrowing and stabilisation, characterised by the spread and growth of vegetation in the river corridor.Observed changes in channel morphology and vegetation succession are natural processes related to actively meandering rivers. However, it has been shown that extensive bank erosion during the flood and subsequent land cover dynamics were primarily triggered by anthropogenic removal of riparian vegetation exemplifying how inadequate and isolated river management decisions may increase bank erosion and lead to a loss of agricultural land in floodplain areas.
Estimation of the Global Root Mean Square Error of Selected Gravitational Field Functionals Calculated by Integral Transforms
Authors: Belinger Jiri , Pitonak Martin , Trnka Petr , Novak Pavel , Sprlak Michal
Published: March 2024

Integral transformations of the gravitational field gradients are defined over the entire solid angle on the surface of the sphere. Despite the indisputable progress in satellite gravimetry and gradiometry, gravity field focused satellite missions allow accurate determination of the gravity field with a spatial resolution of 100 km, i.e. only in its long-wavelength part. However, there is also a need for high-resolution gravity field models at regional, national or continental scales, especially concerning the determination of the quasi-geoid or geoid. On the other hand, potential weakness of ground-based data is the long-wavelength gravity field accuracy and limited availability due to several constraints (e.g. deserts, lakes and large rivers, forests, or lack of goodwill between neighboring countries to share sensitive data). The ideal scenario combines ground and satellite data that complement each other.In this contribution, relations defining the estimation of the global root mean square errors of selected gravitational field functionals using integral transformations will be derived and presented. For practical calculation, knowledge about the accuracy of measured terrestrial data and formal errors of global satellite models of the Earth's gravity field will be utilized.
Fine-scale microclimate data improve species distribution models of forest plant species
Authors: Van Meerbeek Koenraad , Haesen Stef
Published: March 2024

In recent decades, species distribution models (SDMs) have become pivotal in forecasting how changing environmental conditions impact species distributions across space and time. Most SDMs rely on correlations, utilizing statistical or machine-learning techniques to infer links between species occurrences and their environment. Typically, these models rely on a traditional set of bioclimatic variables, often available at a coarse spatial resolution of 30 arc seconds or less. These macroclimatic data are derived through interpolating weather station data, essentially reflecting the free-air temperature conditions in open ecosystems. However, a significant portion of terrestrial life on Earth and many critical ecological processes respond to climate conditions at much finer scales beneath the canopies of trees. Neglecting this mismatch might lead to inaccurate predictions, misinterpretations, and potentially flawed conservation decisions. Hence, there's a pressing need to incorporate finer-scale microclimate data in ecological modelling to ensure more accurate assessments and informed conservation strategies.By developing an innovative spatial machine learning model capable of quantifying the temperature buffering capacity of European forests at very fine resolutions, we crafted the ForestClim database, containing a novel set of bioclimatic variables. These variables unveil the intricate microclimatic temperature variations within forest ecosystems, marking a significant scientific breakthrough that shows promise to enhance ecological models and predictions. Furthermore, by freely sharing this data, we lower the threshold for fellow ecologists to incorporate pertinent microclimatic information into their research.Leveraging the open-access ForestClim database, we further assessed how large-scale, gridded microclimate temperature data affect the accuracy of SDMs of European forest plant species and how their modelled environmental niches and projected geographic ranges differ from conventional SDMs. The study's findings demonstrate that SDMs based on microclimate significantly outperform their macroclimate-based counterparts. They also reveal the introduction of a systematic bias in thermal response curves when relying on macroclimate-based models, potentially leading to inaccuracies in forecasting range shifts. Furthermore, the inclusion of microclimate data in these models enables the identification of microrefugia within the landscape - areas where species can find a stable and suitable climate amid unfavourable, changing macroclimatic conditions. This newfound information holds particular significance in the realm of conservation science, as microclimate-based SDMs prove to be valuable tools for gaining insights into biodiversity conservation in the face of climate change. This is especially pertinent given the increasing policy and management emphasis on conserving refugia worldwide.
Large igneous province degassing contributed to elevated atmospheric CO2 concentration in the Eocene
Authors: Wang Xiangsong , Sun Min , Zhao Guochun
Published: March 2024

Deep carbon recycling plays a critical role in regulating Earth’s atmospheric CO2 and climate changes through time. However, the fate of subducted carbonate and potential driving factor of elevated atmospheric CO2 concentration in the Eocene are not well constrained. Here, we report Mg-Ca isotope of the Cenozoic (48 Ma) large igneous province (LIP) in the western Tianshan, to trace recycled marine carbonates in the deep mantle and evaluate the amount of magmatic degassed CO2. The basalts possess remarkably lighter δ26Mg and δ44/40Ca values than those of mantle, suggesting a source contributed by isotopically light recycled surficial carbonates. The quantitative modeling of Mg-Ca-Sr-Nd-Pb isotope reveals the Tianshan LIP magmatic CO2 degassing flux (~1.4–4.1 Pg/year) is two orders of magnitude higher than that of arc magmas. We highlight the subducted Neo-Tethyan oceanic lithosphere provided abundant recycled carbonates into mantle source of Tianshan LIP and induced high CO2 degassing fluxes, which contributed to elevated atmospheric CO2 during the Eocene.Acknowledgements: The present study was financially supported by Hong Kong Research Grant Council Joint Laboratory Funding Scheme (JLFS/P-701/18), NSFC Major Project (41890831) and Hong Kong RGC grants (17307918 and 17308023), and HKU Internal Grants for Member of Chinese Academy of Sciences (102009906) and Distinguished Research Achievement Award (102010100). This work is a contribution of the Joint Laboratory of Chemical Geodynamics between the University of Hong Kong and Guangzhou Institute of Geochemistry, Chinese Academy of Sciences.
Predicting extinction risk by range loss: Evidence from the fossil record
Authors: Straube Eileen , Steinbauer Manuel , Finnegan Seth , Mathes Gregor
Published: March 2024

Climate change is one of the main drivers for the wave of species extinctions predicted for this century. IPCC extinction risk assessments are based in part on predicted climate-driven reductions in the geographic ranges of focal species (range loss). This builds on the well-established IUCN (2022) Red List criterion, in which a species is considered critically endangered (>50% extinction risk) if it loses ≥80% of its geographic range. However, while there is clear evidence that extinction risk is related to the absolute geographic range of a species, the empirical relationship between range loss and extinction risk is not well understood. Using fossil evidence of true extinctions over the past 23 million years, with 2600 range change observations of 1215 marine genera, this study implements a Bayesian hierarchical weighted generalized additive model to investigate how extinction risk changes with the percentage decrease in geographic range of a genus. Results clearly indicate how extinction risk increases non-linearly with range loss. Taxon dependent differences in the relationship between extinction risk and range loss indicate great potential for adapting its application in extinction risk predictions and the IUCN criteria.
Shifting hydrological process importance in alpine catchments: Combined effects of climate and land cover change on alpine evapotranspiration
Authors: Herzog Anna , Vormoor Klaus , Bronstert Axel
Published: March 2024

In alpine catchments, evapotranspiration (ET) is regularly considered a minor component of the hydrological system and is therefore only rudimentarily regarded in modelling studies and climate change projections. The focus is usually on snow and glacier related processes, projecting a rapid retreat of glaciers in central Europe within the next few years and decreasing snow volumes at lower elevations due to climate warming. This leads to a reduction in the dominance of snow and glacier related processes. Changes in vegetation characteristics due to climate- and/or land use change will presumably lead to a relative increase in the importance of other processes such as ET, interception and soil moisture, which will affect spatial and temporal variations in discharge generation.To identify spatial and temporal patterns of changing process importance, a case study of the Fundusbach catchment in Tyrol, Austria is conducted using the fully distributed and physically based model WaSiM-ETH. As the process representation within all hydrological models is affected by parameter equifinality, substantially different parameter combinations and therefore process representations can lead to similar values of performance criteria when looking at discharge only. To address this issue, elevation dependent, spatial and temporal parameter sensitivity analysis is coupled with a multi-objective calibration. This approach aims to improve the spatial and elevation dependent process representation within the model domain. Instead of calibrating on different output variables, additional field and remote sensing data are used to constrain the parameter space of individual submodels and thus the process behaviour. In a final step, the constrained model is calibrated against discharge. Based on this reference model, scenario analyses are carried out to investigate individual process responses to changes in climate and land use.The results show, that integrating additional field data and constraining the calibration parameter space considerably improves the process representation within the model. Furthermore, first results show, that changes of the land cover do not influence the overall discharge regime, but ET and soil moisture. Increasing amounts of shrub cover limit infiltration and evaporation, while interception and soil moisture increase. Most process responses intensify with increasing elevation and reflect the spatial patterns of land cover.
Comparing multisensor optical-radar approaches for snow water equivalent retrievals
Authors: Tarricone Jack , Palomaki Ross , Rittger Karl , Marshall Hans-Peter , Nolin Anne , Vuyovich Carrie
Published: March 2024

No current remote sensing technique can accurately measure snow water equivalent (SWE) from space for mountain hydrologic applications. Optical sensors are robust for measuring the fractional snow-covered area (fSCA) at various spatial and temporal resolutions. Yet, these optical methods are limited by cloud cover and do not provide information on SWE. Synthetic aperture radar (SAR) can penetrate clouds, has a fine spatial resolution, and various algorithms allow us to quantify both SWE magnitude and changes. However, SAR cannot discriminate between snow-free and snow-covered areas when the snow is dry. To address this SWE monitoring challenge, we evaluate a multisensor approach that leverages the strengths of both optical and radar sensors. Our study aims to better understand the variability between common snow cover data products and how that uncertainty propagates into InSAR-based SWE retrieval techniques. We analyzed four UAVSAR InSAR pairs from one flight line over the Sierra Nevada, CA, during the SnowEx 2020 campaign and compared six satellite-based snow cover products. First, we computed InSAR-based SWE change estimates using in situ snowpack data. We then compared the summed SWE change values with a moving window analysis to quantify product variability. Lastly, we tested the volumetric SWE results for statistical differences. Results show that moderate-resolution (375–500 m) NDSI-based products provide broadly similar volumetric SWE change results to those using more complex spectral unmixing and machine learning retrieval methods. This suggests that the readily available moderate-resolution snow cover products from MODIS are adequate for an optical-radar SWE monitoring approach. Future work should focus on understanding how sub-canopy snow in forested regions affects snow cover product accuracy and variability. Furthermore, near-real-time, high-resolution cloud- and gap-filled optically-derived snow cover data will be important for supporting water resources decision-making.
From plots to theory: young students build their good practice on climate changes
Authors: Martelli Mauro
Published: March 2024

Energy and climate changes are complex issues with rapidly developing science and the potential for controversy. The amount of time teachers are spending on these topics is going up significantly, but how can educators effectively bring these important subjects into their classrooms? My response applied to 11-14 year-old students is to start from plots nearly without any discussion before. Simple plots that show the most important indicators of climate change (i.e., time-behaviour of concentration of CO2, surface temperature, sea level, arctic sea ice extent, etc.).Time plots do not end in the present time but are extrapolated to the next 20-30-40 years using models from qualified scientific literature, that show how the choices of decision-makers and also our behaviour can affect the climate changes. This becomes a powerful starting point for a discussion that will arise from students as soon as they realize on how the situation is rapidly changing. The discussion will naturally end-up with students that focus that a combination of strategies is needed to reduce greenhouse gas emissions. The most immediate strategy is conservation of oil, gas, and coal, which we rely on as fuels for most of our transportation, heating, cooling, etc. In students life that means to modify some habits in order to save energy and limit gas emissions. Student achieve this conclusion by their selves, while the teacher has only the role to coordinate the work.Some strategies to keep this subject interesting and stimulating are used: plots are done by students not in their notebooks during desk-work but in high dimensions in the school-gym, using when possible the lines of basket of volleyball pitches and completing them with paper tape. This involves the students usually less interested in the activities in traditional classroom work and allows team work in groups of 3-4 students. This also reinforces math abilities and demonstrates how math theory merges with reality, a link that is not always caught by young students.
Impact of an immobile, mobile and permeable phase on mixing-driven reactions in porous media
Authors: Jimenez-Martinez Joaquin , Zhang Xueyi , Markale Ishaan , Kurz Dorothee , Dou Zhi , Carrel Maxence , Morales Veronica , Holzner Markus
Published: March 2024

Understanding chemicals mixing and reactions in porous media is critical for many environmental and industrial applications. In the presence of a non-wetting immiscible phase (e.g., gas) within the pore space, it can remain immobile, giving rise to the so-called unsaturated flow, or it can move, resulting in a multiphase flow. In other cases, the immiscible phase can be permeable, as it occurs with biofilms growing within the pore space. We combine experiments and numerical modeling to assess the impact of saturation (fraction of the pore volume occupied by the wetting phase), multiphase flow (stationary two-phase flow), and the presence of permeable biofilm within the pore space on mixing-driven reactions. The product formation is larger for a given flow rate as saturation decreases, while for a given Peclet, it is the opposite. In multiphase flow conditions, for a given flow rate of the wetting phase, the product formation depends on the flow rate of the non-wetting phase. In the presence of biofilms, the product formation is enhanced compared to their absence and is further enhanced with a heterogeneous permeability within the biofilm.
Similar freezing spectra of particles in the phyllosphere as at mixed-phase cloud height
Authors: Einbock Annika , Conen Franz
Published: March 2024

The phyllosphere is a major source of airborne microorganisms. Some of these microorganisms can act as ice nucleating particles (INPs) and initiate droplet freezing in supercooled clouds. Despite their role in this critical atmospheric process, little is known about the spatiotemporal variations of biological INPs at their source. We investigated this variation on the scale of single (or few) leaves about fortnightly from late summer throughout leaf senescence in two lime (Tilia platyphyllos), beech (Fagus sylvatica), cherry (Prunus avium), and walnut (Juglans regia) trees (n = 2 x 4 x 8 = 64) on a hillside (Gempen, 650 m a.s.l.) in north-western Switzerland. The overall result comprising all species shows an increasing trend in the median cumulative concentration of INPs active at -10 °C (INP-10) from 4 INPs cm-2 leaf area at the beginning of August to 38 INPs cm-2 in mid-November. Further, median INP-10 concentration was positively correlated with relative humidity throughout the 24 h prior to sampling (Spearman’s r = 0.90, p = 0.005, n = 8). Differential INP spectra between -3 °C to -10 °C displayed clearly defined patterns in 53 of the overall 64 samples. In 28 of these 53 samples (53%), the additional number of INPs activated with every 1 °C step in cooling increased steadily with decreasing temperature. In another 21% we observed a significant peak in the temperature step from -8 °C to -9 °C (i.e., around -8.5 °C), and in further 17% a peak around ‑7.5 °C. Interestingly, these types of spectra were similarly often found in air samples with clearly defined pattern (n = 53) at the high-altitude observatory Jungfraujoch (3580 m a.s.l., Switzerland) in summer 2022 (55% steady increase, 17% peak at -8.5 °C, 21% peak at -7.5 °C). This consistency in spectral pattern supports the notion that forests are a major source of biological INPs affecting atmospheric processes. It also prompts the question which parameter – perhaps leaf wetness duration? – could influence the abundance of biological INPs on both scales, on single leaves as well as in the airshed of a high-altitude observatory.
Change point analysis of seasonal ozone trends and distribution across the United States
Authors: Chang Kai-Lan , Cooper Owen R
Published: March 2024

We present a comprehensive regional analysis of trends and variability in daily maximum 8-hour average ozone across the contiguous United States over 1990-2023. At the first stage, we evaluate the trends based on various seasonal percentiles at all available monitoring sites. Secondly, the overall regional trends (Western and Eastern USA) are derived at various seasonal percentiles. Results show that consistent and strong negative trends can be found in the eastern USA at the 95th and 50th percentiles in spring, summer and fall since the early 2000s, while winter trends are increasing. The similar seasonal trends are found in the Western USA, but with weaker magnitudes of trends. Throughout the analysis implications of the correlations between heatwave frequency/intensity and ozone variability are discussed.
Extracting and filtering the Common Mode Signal of GNSS coordinate time series via Independent Component Analysis and Multiresolution analysis
Authors: Teza Giordano , Pesci Arianna , Elia Letizia , Meschis Marco
Published: March 2024

Time series related to a GNSS network at regional scale, or larger, generally show a spatially correlated component, called common-mode signal (CMS), related to both unmodelled geophysical processes, including environmental loading effects, and technique-dependent systematic errors that persist after data processing. The CMS estimation is very useful for two reasons: (i) untreated CMS leads to long-period noise in coordinate time series which induces bias and higher uncertainty in velocity estimates, so that many authors prefer the term CME (Common Mode Error) instead of CMS; (ii) whether it is possible to adequately discriminate between the components of the CMS, it is then possible to obtain relevant information regarding some geophysical phenomena.Independent Component Analysis (ICA) is particularly useful for estimating the CMS because the ICA components show insightful correlations, e.g., with atmospheric and non-tidal ocean loading displacements. For this reason, we propose a small MATLAB toolbox, partially compatible with GNU Octave, for ICA-based CMS estimation and, if required, filtering.The ICA is implemented using a FastICA algorithm in which data whitening is carried out using a Principal Component Analysis (PCA) modified in order to allow the use of incomplete time series. In this way, in the case of short periods of data loss (a few days or also some weeks), the ICA is obtained without use of data interpolation. The only used preprocessing technique is detrending. The spectral content of each ICA component can be studied by means of both frequency and time-frequency analysis and the filtering can be carried out either in the frequency domain or by means of Multiresolution analysis (MRA), according to the user’s choice. This filtering requires continuity of the time series and, therefore, in the case of short periods of data loss (a few days, at most a few weeks), interpolation is needed to build the required continuity; for non-short periods of data loss, no interpolation is implemented. The fact that the interpolation occurs after the CMS analysis, and therefore has no possible effect on its estimate, should be noted.The toolbox, which is designed to be used both independently and together with the StaVel/GridStrain toolbox developed by the same authors, will soon be made available on the Harvard Dataverse. Development of the Python version is planned.In order to test the validity of the proposed approach in the case of real data, it is applied to vertical data related to a network of some dozens of GNSS stations located in Southern Italy (Sicily and Calabria) and Greece (North-Western Greece and Peloponnese).