bluuebunny/crossref_metadata_2025 huggingface dataset:
Stable isotope analysis of atmospheric CO2 using a Gasbench II – Cold Trap – IRMS setting
Authors: Leitner Simon , Meeran Kathiravan , Watzinger Andrea
Published: March 2024

The measurement of the stable carbon and oxygen isotope ratio of (atmospheric) carbon dioxide (CO2) is a useful technique for the investigation and identification of the sources and sinks of the most abundant greenhouse gas by far. For this reason, we are presenting a measuring system here that enables a wide range of users to carry out stable isotope analysis of atmospheric CO2 using off the bench hard- and software.The fully automated system uses cryogenic and gas chromatographic separation to analyse CO2 from 12 mL whole air samples and consists of an autosampler, a Gasbench II, a downstream cryo trap and a continuous flow gas interface feeding into a sector field mass spectrometer (GC Pal/Gasbench II/Cold Trap/Conflo IV/DeltaV Plus). The evaluation of the system performance was based on the analysis of samples prepared from eight CO2 sources (four CO2 reference gases and four artificial air tanks).The overall measurement uncertainty (averaged single standard deviation (1σ) of measurement replicates from each CO2 source) in the determination of the carbon and oxygen isotope ratio was 0.04 ‰ and 0.09 ‰ (n=24). Furthermore, we were able to show that the measurement data also allowed for the quantification of the CO2 mole fraction, with a precision of 1.2 µmol mol-1 in the analysis range of 400 to 500 µmol mol-1.The method to be presented was summarized and published in the form of a protocol (DOI: 10.1002/rcm.9647) providing a detailed description of the measurement setup and the analysis procedure, how raw data should be evaluated and gives recommendations for sample preparation and sampling to enable a fully automated whole air sample analysis. We look forward to further discussion with interested users to elaborate on potential improvements/extensions/application options.
Inter-row soil management affecting the soil-plant-water system in vineyard 
Authors: Horel Ágota , Czelnai Levente , Zsigmond Tibor , Zagyva Imre , Farkas Csilla
Published: March 2024

The objectives of the study was to 1) investigate soil-plant-water interactions based on field measurements of plant reflectance and soil water content (SWC) in different inter-row managed vineyards, and 2) modeling changes in the SWC due to differences in soil physical parameters among slope positions and management methods. The study explored the impact of three different soil management practices on grapevine growth and soil health in vineyards: tilled (T), cover crops (CC), and perennial grass (NT) inter-rows. Data was collected for 2022 and 2023. At each study slopes, we had two measurement points along a slope section. To continuously monitor soil water and temperature conditions, sensors were strategically positioned at two depths of 15 cm and 40 cm below the soil surface along the slopes, both at the upper and lower points of the vineyard, while topsoil SWC was measured bi-weekly. Normalized Difference Vegetation Index (NDVI) and Photochemical Reflectance Index (PRI) sensors were used to measure leaf reflectance, while handheld instruments were used to measure additional NDVI and leaf Chlorophyll contents (SPAD). For the hydrological modeling we used SWAP (Soil-Water-Atmosphere-Plant), where the rswap R-package was used for calibration (2020 15 and 40cm data), validation (2021 15 and 40cm data), and statistical evaluation.In 2022, all three slopes showed a significantly higher SWC content for the higher points compared to the lower, while in 2023 the grassed slope upper point showed higher SWC (0.18 vs 0.15%). The highest NDVI values were measured for the cover cropped vineyard site (0.68). However, we found no significant differences among NDVI values based on inter-row management or slope position, only the grassed inter-row vineyard had differences in the NDVI values at the lower and upper points (p=0.034). The highest leaf chlorophyll contents were measured for the cover cropped vineyard site (305). Most of the leaf Chlorophyll values were not significantly different among slope positions. Using the SWAP model, data from the cover cropped inter-row vineyard was used for calibration and validation. We found good model fitting (NSE > 0.52; d_daily > 0.81). Reduced-tillage (RT) and drought tolerant plant (DTP) management scenarios were run to simulate SWC changes over time. Preliminary data shows that DTP significantly reduced, while RT did not significantly affect our site’s SWC.Acknowledgments: This material is based upon work supported by the Hungarian National Research Fund (OTKA/NKFI) project OTKA FK-131792. The research presented in the article was carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF 2.3.1 21 2022 00008 project.
Machine Learning an All-Atom Empirical Force Field for a Water-Silica System
Authors: Camposano Anthony Val , Sveinsson Henrik Andersen , Malthe-Sørenssen Anders
Published: March 2024

Molecular modeling of the interaction between silica and water provides a better understanding of how water affects rocks and glasses at the nanoscale. Here, we parametrize a new classical dissociative force field for the water–silica system. We create a classical force field capable of reactive interactions between all chemical species in the water–silica system, using the same functional form by Vashishta et al. to describe bulk water, silica, and silica–water interactions. Using a hierarchical genetic algorithm as a global optimizer and the Nelder-Mead simplex algorithm as a local optimizer, we parameterized the Vashishta force field to reproduce the density, transport properties, and vapor-liquid properties of water. We then used the same method to obtain water–silica interaction parameters to reproduce gas phase orthosilicic geometry and silica surface properties such as silanol concentration, heat of immersion, and the wettability angle of water on a silica surface. For oxygen–silicon interactions in silica, we reuse an existing Vashishta potential parameter set that has been parameterized to reproduce bulk mechanical behavior, surface properties, and fracture properties. Our developed force field can be used to study processes such as dissolution, friction, and stress corrosion fracture in the presence of water over a wide range of thermodynamic conditions for larger-scale and longer-scale simulations.
Estimating The Health Benefits from Air Quality Improvements in Ahmedabad, India Under the National Clean Air Programme
Authors: Kapoor Ritika , Limaye Vijay , Tiwari Abhiyant
Published: March 2024

Outdoor air pollution contributed to an estimated 980,000 deaths in 2019 and imposes an enormous public health burden in India. For many Indian cities, average annual exposures are above the current National Ambient Air Quality Standard (annual average of 40 µg/m3). To provide a roadmap for addressing unhealthy air pollution levels, the Government of India launched the National Clean Air Programme (NCAP) in 2019. The NCAP effort aims to reduce fine particulate matter PM2.5 levels 20–30% by 2024 relative to 2017 levels in 132 cities that are in nonattainment for the annual NAAQS. Ahmedabad,  a city of about 8.5 million people in Gujarat state, in 2017 launched continuous air quality monitoring and has been taking steps to reduce PM2.5 levels through NCAP actions.  We investigated publicly available air quality data for Ahmedabad to evaluate how city air quality has changed during NCAP implementation and deploy an air quality and health impact assessment model to estimate the health effects of city air pollution.Specifically, we configured the Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) with local air pollution, population, and baseline health data to estimate citywide air quality effects on human health from PM2.5 exposures between 2018 and 2022 using air quality exposure-response functions derived from international epidemiological cohort studies. Overall, we find that the average air quality improved slightly in Ahmedabad during the evaluation period, from 63.4 to 56.2 µg/m3 in 2022, based on available air monitoring data. That decrease represents a 7.2% reduction in annual PM2.5 levels, while attainment of the 30% NCAP goal by 2022 would have resulted in an annual PM2.5 level of 44.4 µg/m3 in 2022. Our health effect analysis in BenMAP-CE are estimates changes in annual all-cause mortality by analyzing population-weighted PM2.5 exposures. We estimate that observed reductions in PM2.5 levels from 2018-2022 are associated with 1631 (95% CI, 1234 - 2010) fewer deaths citywide. However, if the 30% NCAP target had been achieved by 2022, the city would have seen 3931 (95% CI, 2984 - 4834) fewer deaths from PM2.5 exposures. Our integrated air quality and health assessment provides a blueprint for other Indian cities to evaluate how air quality changes affecting human health and shows how a focus on the health impacts of cleaner air can support future NCAP implementation efforts nationwide. 
A new predictive approach for assessing local human and climate change stressors on coastal marine ecosystems.
Authors: Bonamano Simone , Bosch-Belmar Mar , Piazzolla Daniele , Federico Ivan , Mancuso Francesco Paolo , Scanu Sergio , Madonia Alice , Causio Salvatore , Biocca Nicholas , Tantillo Mario Francesco , Russi Martina , Fersini Giorgio , Piermattei Viviana , Coppini Giovanni , Sarà Gianluca
Published: March 2024

The potential impacts of climate-related factors (e.g., heatwaves, temperature spikes) and local human stressors (e.g., dredging) on vulnerable and protected habitats in the Mediterranean coastal marine environment can be comprehensively assessed using an innovative predictive approach. This method integrates results from numerical models and species-specific stressor tolerance curves and thresholds derived from dedicated laboratory experiments. Focusing on the endemic Mediterranean Posidonia oceanica and coralligenous habitats near the port of Civitavecchia on the western coast of Italy, we analyzed the potential disturbance caused by the occurrence of interacting stressors, increasing temperature and turbidity. A new composite index was developed to evaluate potential effects, considering findings from hydrodynamic and sediment transport models, as well as the temperature and turbidity tolerance of the studied habitats. Lower index values indicate a higher risk of habitat regression due to global warming or unsustainable coastal activities (in the absence of mitigation measures, such as an Early Warning System, EWS).Within the Renovate project, adopting an ecosystem approach for compensation and mitigation actions in the coastal marine environment, the new index was applied to assess the effects of dredging activities for the expansion of the port of Civitavecchia. Additionally, it was used to distinguish impacts on the same habitats caused by heatwaves affecting this coastal stretch. This index will contribute to the development of EWS and the formulation and implementation of risk assessment and management plans in coastal areas.
Using satellite observations to examine the role of land cover and fires in driving atmospheric composition over the southern Amazon
Authors: Sands Emma , Pope Richard , Doherty Ruth , O'Connor Fiona , Wilson Chris , Pumphrey Hugh
Published: March 2024

We exploit satellite datasets of spatio-temporal distributions of atmospheric composition for the rainforest and savanna region on the southern boundary of the Amazon to understand how its emissions of biogenic volatile organic compounds (BVOCs) and local pyrogenic emissions impact the atmosphere. In particular, we explore the relationship between land cover change, considering vegetation type (e.g. broadleaf forest, savanna, grassland) and Leaf Area Index (LAI), and burned area and atmospheric composition. In this study, we investigate these relationships over the southern Amazon for the period 2001-2019, focussing on seasonal and spatial patterns. We utilise data for five chemical species: total column isoprene (TCC5H8), total column methanol (TCCH3OH), tropospheric column nitrogen dioxide (TCNO2), total column carbon monoxide (TCCO) and total column formaldehyde (TCHCHO), as well as aerosol optical depth (AOD).We find burned area approximately delineates the areas of change in dominant vegetation cover type over time.  Robust relationships were found between TCC5H8 and forest cover, and TCNO­2­ and burned area. Here, we find that TCC5H8 linearly increases by 1 × 1014 molecules cm-2 with an increase of 1 percentage point in broadleaf forest cover. This is equivalent to densely forested regions having column isoprene ­­values four times greater than those with no­ forest cover. There is a strong power law relationship between TCNO2 and burned area. Overall, there is a larger increase in TCNO2 in regions of lower, though still substantial, biomass burning (i.e. potentially new regions of burning/deforestation). These relationships highlight the relatively short lifetimes of the two species such that their spatial extent is largely confined to their emission source regions.Conversely, TCHCHO, TCCO and AOD reach maximum values for high broadleaf forest coverage and high burned areas, suggesting a mixed influence of both biogenic and pyrogenic sources, likely due to the longer lifetimes of these species and aerosols, allowing them to mix and be transported further from their emissions sources. Broadleaf forest cover and burned area do not appear to have a substantial impact on methanol, which is elevated over a region of savanna and grasslands in the northeast of the study region.The results highlight the potential for air quality impacts from the biogenic and pyrogenic emissions and their interactions that differ seasonally and regionally, and illustrates how land cover and land use change exerts a strong control on isoprene and nitrogen dioxide concentrations over remote regions.
New Frontiers in Geodynamics
Authors: Gerya Taras
Published: March 2024

Geodynamics is an actively expanding young quantitative science, which defined its mission very generally as introducing of physical-mathematical methods into traditionally observations-focused Earth and planetary sciences in order to understand and quantify origin and evolution of Earth and other planets. As such, this young science is not limited by any specific object or subject and widens its scope through time. This is a very natural process (‘instinctive evolution’) since human scales of direct observation are extremely limited in both time and space and since rapid progress of quantitative physical-mathematical and computational methods offers every day new and exceptional possibilities to explore sophisticated physical-mathematical models for understanding intrinsically complex natural processes. As the result of this ‘instinctive evolution’, new frontiers in geodynamics are (and always were) defined by its expansion toward other fields. Initially, Geodynamics mainly expanded towards Structural Geology and Tectonics. Currently, new Geodynamics expansion tendencies are clearly visible toward: Seismology, Geomorphology, Geochemistry, Petrology, Climatology, Planetology/Astronomy and Biology/Astrobiology. In this lecture, I will give some recent examples of this impressive expansion and outline future expectations and challenges.
Post-processing and visualization of ISR data 
Authors: Araujo Juan , Johansson Stefan , Westman Assar , Bodin Madelen
Published: March 2024

Incoherent scatter radar (ISR) techniques provide reliable measurements for the analysis of ionospheric plasma. Measurements of electron and ion densities, temperatures, and line-of-sight velocities are derived by employing antennas that transmit and receive radio waves. Recent developments in ISR technologies are capable of generating high-resolution volumetric data from multiple beam measurements. Examples of such technologies employ the so-called phased array antennas like the AMISR in North America or the upcoming EISCAT_3D in the northern Fennoscandia region. Traditional visualization methods, for example, 2D projections, applied to volumetric images render a reduced set of the available data and important aspects of the data may be lost to the analyst.     We present an interactive approach for the exploration and visualization of spatio-temporal and volumetric ionospheric data. The strategy is targeted at offering the analyst a wider range of alternatives in order to interpret ISR data. The proposed novel strategy allows for the reconstruction of ionospheric volume images by means of a novel sparse interpolation algorithm tailored for the particular features of ISR data. The interpolation offers estimation of gradients and processing of the challenging case of missing data. The reconstructed image is output by using volume rendering combined with customizable transfer functions. We propose to utilize reconstructed volumetric images for the estimation of ionospheric conductivities and volumetric currents, which in turn can be used for studying the evolution of storms and substorms in the ionosphere.
Modulation of crustal and mantle flow systems by a heterogeneous cratonic root: Evidence from seismic azimuthal anisotropy analysis
Authors: Liu Lin , Gao Stephen , Liu Kelly , Li Sanzhong , Yu Youqiang
Published: March 2024

In contrast to many prior studies that relied on station-averaged shear-wave splitting (SWS) measurements and sparsely distributed stations, this study takes advantage of the recent deployment of broadband seismic stations at intervals of less than 50 km to explore the intricate seismic azimuthal anisotropy between the dynamic Tibetan Plateau and the stable North China Craton. Our analysis encompasses 6,409 high-quality individual SWS measurements from 465 closely spaced stations located along the boundary of the northeastern Tibetan Plateau and the western North China Craton. Notably, twenty of these stations show splitting parameters with a π/2 periodicity based on azimuthal variations, indicating a complex double-layer horizontal anisotropy structure. The anisotropy of the upper layer is linked to ductile flow in the middle-to-lower crust originating from the Tibetan Plateau. This flow encounters the rigid lithosphere of the Alxa Block, leading to a bifurcation into northeastward and southeastward directions. The anisotropy in the lower layer, exhibiting fast orientations in an NW-SE direction, is consistent with the observed one-layered anisotropy and aligns with the absolute plate motion (APM) of the Eurasian plate. The coherence in the spatial distribution of splitting parameters indicates that the predominant source of observed anisotropy is asthenospheric flow. This mantle flow exhibits a southeastward orientation beneath the Alxa block, transitioning to an almost eastward direction along the thinner lithospheric passage between the Ordos and Sichuan cratonic keels. This pattern unveils the influence of cratonic edges in modulating localized mantle flow systems.
Daily-weekly scale precipitation events in the monsoon marginal zone recorded by high-resolution δ18O of land snail shells
Authors: Zhang Qian , Yan Hong , Dong Jibao , Wang Guozhen , Jia Yana , Li Xiangzhong
Published: March 2024

Weather-scale precipitation have a significant impact on ecosystems and human activities. Reconstructing weather-scale precipitation events is critical to improving our understanding of precipitation event mechanisms. Currently, the snail shells ultra-high resolution δ18O records obtained by secondary ion mass spectroscopy (SIMS) is the main methods of reconstruction the terrestrial weather-scale precipitation events. However, research in this field is limited due to the rarity and costliness of SIMS instrumentation, as well as the complexity of sample preparation. In this study, we collected three modern land snails (Cathaica fasciola) from the Shizuishan area in Northwest China in June, September, and December 2021. The shells of these snails were sampled continuously with a spatial resolution of ~700μm and tested using gas-source mass spectrometry (GSMS) to obtain high-resolution δ18O records. The results showed that the δ18O of snails shell (δ18Oshell) of different snails grown at the same time period were well reproducible. We obtained the growth rate of Cathaica fasciola is 546μm/day from June to September. This growth rate is obviously faster than Xingyang (181μm/day from June to September) and Xi'an (56μm/day from April to September). The observed disparity in growth rates may be attributed to the snail survival strategy changes, which appear to be more efficient in water usage in the monsoon margin zone. More importantly, the δ18Oshell exhibited sensitivity to precipitation, as evidenced by three negative fluctuations in δ18Oshell record that corresponded to three precipitation events during the period. These findings indicate that δ18Oshell records obtained by GSMS could effectively capture weather-scale precipitation information in the monsoon margin region. GSMS is widely used, less costly for testing, and relatively simple for sample preparation. This greatly improves the feasibility and applicability in reconstruct weather-scale precipitation events under different climatic conditions using δ18Oshell record, and deepens our understanding of the mechanisms such events. Meanwhile, this finding holds significance in unraveling the intricate nature of weather-scale precipitation events. 
An efficient approach for NDT diagnosis of defect causes in airfield concrete pavements 
Authors: Gkyrtis Konstantinos , Armeni Angeliki , Plati Christina , Loizos Andreas
Published: March 2024

Airports form a core part of the built environment serving fast and safe transportation of human beings and freights, thereby fostering economic development at both national and international levels. Maintaining resiliency in the airport pavement infrastructures is a critical task for airport stakeholders. The first and foremost action to achieve this goal is to ensure construction sufficiency. Because of their significance, airfield pavements need to be designed and constructed as high-quality and low-risk structures. In the unlike event of construction malpractices, robust decisions are needed. Nondestructive testing methods and advanced monitoring systems offer unique opportunities for a non-invasive inspection of the built structures that help airport stakeholders to draw their strategy.This study proposes a best practice approach in the form of a diagnostic framework developed and applied for the inspection of construction problems along the concrete runway pavement of a regional airport that exhibited cracking and deterioration in the early post-construction period. Traditional coring and laboratory testing on the concrete material did not yield any considerable findings. On the contrary, the use of the Falling Weight Deflectometer (FWD) helped (i) to comparatively assess the deflectometric response of individual concrete slabs, (ii) to assess the load transfer efficiency at cracks and joints, and (iii) to estimate durability levels of each slab’ s area. The collected data from this three-pillar framework enabled a full mapping of the concrete slab condition that helped to discriminate which slabs required minor maintenance treatments and/or complete reconstruction. As such, the inclusion of nondestructive assessment methods for site investigation contributed to an optimized and cost-effective action plan for the preservation of durable and sustainable airfield structures.
Thermally-driven orographic convection initiation is sensitive to terrain steepness
Authors: Serafin Stefano , Göbel Matthias , Rotach Mathias W.
Published: March 2024

Diurnal mountain winds favor the onset of deep moist convection, both because the related horizontal and vertical transports of heat and moisture make the environment more supportive, and because they may lift air parcels above their level of free convection. We study the effect of cross-valley circulations on convection initiation under synoptically undisturbed and convectively inhibited conditions, using idealized large-eddy simulations with the Weather Research and Forecasting (WRF) model. We consider quasi-2D mountain ranges of different heights and widths and we contrast convection initiation over relatively steep mountains (20 % average slope) and less steep ones (10 %). Under identical environmental conditions, steeper mountains cause stronger thermal updrafts at ridgetops, but lead to a delayed onset and lower intensity of deep moist convection. Analysis of the ridgetop moisture budget reveals the competing effects of moisture advection by the mean thermally driven circulation and of turbulent moisture transport. At mountaintops, the divergence of the turbulent moisture flux offsets the convergence of the advective moisture flux almost entirely. Considering in-cloud vertical profiles of equivalent potential temperature, we demonstrate that buoyant updrafts over steeper mountains are more strongly affected by the turbulent entrainment of environmental air. This depletes their moisture and cloud water content and makes them less effective at initiating deep convection. The weaker convection over steeper mountains is a robust finding, valid over a range of background environmental stability and mountain sizes.
Implementation of a reproducible pipeline for producing seasonal Arctic sea ice forecasts
Authors: Stöckl Vanessa , Grüning Björn , Fouilloux Anne , Iaquinta Jean , Coca-Castro Alejandro
Published: March 2024

This work highlights the integration of IceNet (https://doi.org/10.1038/s41467-021-25257-4), a cutting-edge sea ice forecasting system leveraging numerous Python packages from the Pangeo ecosystem, into the Galaxy platform—an open-source tool designed for FAIR (Findable, Accessible, Interoperable, and Reusable) data analysis. Aligned with the Pangeo ecosystem's broader objectives, and carried out in the frame of the EuroScienceGateway project (https://eurosciencegateway.eu), this initiative embraces a collaborative approach to tackle significant geoscience data challenges. The primary aim is to democratise access to IceNet's capabilities by converting a Jupyter Notebook, published in the Environmental Data Science book (www.edsbook.org), into Galaxy Tools and crafting a reusable workflow executable through a Graphical User Interface or standardised APIs. IceNet is meant to predict Arctic sea ice concentration up to six months in advance, and it outperforms previous systems. This integration establishes a fully reproducible workflow, enabling scientists with diverse computational expertise to automate sea ice predictions. The IceNet workflow is hosted on the European Galaxy Server (https://climate.usegalaxy.eu), along with the related tools, ensuring accessibility for a wide community of researchers. With the urgency of accurate predictions amid global warming's impact on Arctic sea ice, this work addresses challenges faced by scientists, particularly those with limited programming experience. The transparent, accessible, and reproducible pipeline for Arctic sea ice forecasting aligns with Open and Science principles. The integrated IceNet into Galaxy enhances accessibility to advanced climate science tools, allowing for automated predictions that contribute to early and precise identification of potential damages from sea ice loss. This initiative mirrors the overarching goals of the Pangeo community, advancing transparent, accessible, and reproducible research. The Galaxy-based pipeline presented serves as a testament to collaborative efforts within the Pangeo community, breaking down barriers related to computational literacy and empowering a diverse range of scientists to contribute to climate science research. The integration of IceNet into Galaxy not only provides a valuable tool for seasonal sea ice predictions but also exemplifies the potential for broad interdisciplinary collaboration within the Pangeo ecosystem.
Rotational Grazing Approaches for Sustainable Peatland Management: A Focus on the Falklands
Authors: Ross Katy , Evans Christopher , Morrison Ross , Carter Stefanie , Page Susan
Published: March 2024

Peatland research, management and restoration efforts have predominantly been focused in the Northern Hemisphere, leaving Southern Hemisphere peatlands, with their confined spatial coverage, relative inaccessibility and smaller research community understudied. To create comprehensive global databases of peat extent, greenhouse gas (GHG) fluxes and support informed restoration efforts, we need to better quantify these Southern Hemisphere peatlands and their role in the global carbon cycle.Situated in the southern South Atlantic, at the periphery of the climate envelope for peat formation, the Falkland Islands archipelago is believed to support the largest proportional peat extent of any country at 43%. However current estimates of GHG exchange are based on direct measurements from neighbouring Patagonian or distant UK peatlands, or estimated from long-term carbon accumulation rates. These inferred values do not capture the influence of the widespread sheep grazing since the mid-17th Century on this peatland landscape, which, for the first 14,000 years, developed without herbivorous mammals. Livestock grazing is now an integral part of the Falklands with 98% of the peatlands being grazed. Confronting challenges such as drying landscapes, diminishing pasture extent, bare soil exposure to wind erosion and declining wool prices, farmers are exploring alternative holistic and rotational grazing systems or complete removal of sheep to set a trajectory towards peatland restoration.Over an annual cycle between 2022-2023, direct monthly measurements of CO2 and CH4 were conducted across 13 sites in East Falkland using static chambers. These measurements provide the first directly measured annual estimates of GHG emissions from Falkland peatlands under different management approaches. These measures of ecosystem exchange have been enhanced with the deployment of sediment traps and erosion pins to quantify particulate carbon loss, with preliminary results indicating this pathway of loss to be several orders of magnitude higher than observed in Northern Hemisphere peatlands.This integrated approach, with the results presented here, facilitates a comprehensive understanding of the impact of grazing and land management practices on peatland carbon balance. While also providing evidence alongside existing biodiversity and socioeconomic studies to determine which grazing systems may be most conducive to sustainable peatland management in the Islands.
Sensitivity analysis on gravity change data in order to observe mantle convection
Authors: Root Bart , Thieulot Cedric
Published: March 2024

With the GRACE-FO mission well underway and the plans of the MAGIC/NGGM mission in the future, there will be several decades of satellite gravity change data available. Both periodic and secular mass changes are studied with this data, mostly surface mass changes like hydrology, ice melt, Glacial Isostatic Adjustment, and large Earthquakes. With the increasing time period of the gravity data set, smaller variation in the signal can be detected, especially linear secular changes. One of the processes that would result in small secular gravity rate is the mass change due to mantle convection.We perform various sensitivity analysis studies to understand the added benefit of detecting mantle convection with satellite gravity change observations. A fast stoke solver (FLAPS) is developed that is based on an axisymmetric half annulus geometry. A density and viscosity structure can inserted as well as test anomalies to understand the effect of the mantle flow on the gravity change observations. The model evolves over 50 years after which the difference between the initial and final state is computed. This will also give the rate of change information. Realistic Earth models (PREM) as well as synthetic models are tested to better understand the sensitivity of the gravity change data.The gravity change observations are sensitive to the absolute viscosity state of the mantle. This is contrary to dynamic topography and geoid data, which do not have this sensitivity and studies using these data always have an ambiguity wrt. viscosity state. Moreover, it seems that the gravity change data is more sensitive to the lower mantle of the Earth. This sensitivity can be very helpful in further exploration of Core-Mantle Boundary structures. The modelled magnitude of the gravity change linked to global mantle convection seems to be larger then the formal error estimates of the GRACE and GRACE-FO instrumentation. A longer acquisition period will reduce the secular errors in the ocean, atmosphere and tidal correction models, such that eventually mantle convection can be studied directly by satellite gravimetry.
The relationship between atmospheric blocking and Arctic-midlatitude thermal gradient
Authors: Cadau Marco , Messori Gabriele , Gaetani Marco , Fosser Giorgia , Bordoni Simona , Buizza Roberto , Sannino Gianmaria
Published: March 2024

Atmospheric blocking is known to be one of the most important drivers of large-scale atmospheric variability at mid-high latitudes. Blocking events consist of a disruption and/or deceleration of the mean westerly circumpolar flow, and are generally associated with large-scale high-pressure patterns, which may be connected with the occurrence of climate extremes, such as heat waves and cold spells. Atmospheric dynamics in the Arctic region may be very important in shaping the spatial and temporal patterns of blocking at mid-high latitudes in the Northern Hemisphere, and consequently the occurrence of associated climate extremes. In particular, the difference between Arctic and mid-latitude temperatures is tightly associated with the Ural blocking (UB) activity. A causation relationship has been identified, with the UB triggering Arctic warming and Eurasian cold spells, and in turn leading to a weaker Arctic-midlatitudes thermal gradient (AMG).  The objective of this study is to investigate the physical mechanisms underlying the AMG-UB relationship. In particular, the circulation patterns associated with the nonlinear part of the UB-Arctic interannual relationship are analysed in winter (December-to-February) from 1940 to 2023. To this aim, atmospheric variables are extracted from the ERA5 reanalysis datasets.Results show that when high UB activity and strong AMG are observed, atmospheric blocking develops also over multiple areas relevant for milder and more humid air transport from mid latitudes into the Arctic region. Conversely, when low UB activity and weak AMG – hence associated with Arctic warmer than average – are observed, UB moves northwards, over Barents-Kara seas, and remote areas in the mid-latitudes and the subtropics, such as northwestern Africa and northwestern Atlantic Ocean, are teleconnected with the Arctic region.By highlighting the complex nature of the atmospheric blocking modulation of the AMG, these findings are relevant to the comprehension of the leading factors of Arctic Amplification, and to the understanding of the role of atmospheric blocking in determining winter cold spells and extreme temperature events over mid-latitude regions.
Leveraging hydrological constraints on bog morphology to better map raised peatlands
Authors: Cobb Alex , Dommain René , Yeap Kimberly , Hannan Cao , Dadap Nathan C. , Bookhagen Bodo , Glaser Paul H. , Harvey Charles F.
Published: March 2024

Raised peatlands, or bogs, are recognized as exceptionally carbon-dense terrestrial ecosystems in which peat accumulates into convex shapes that rise above their boundaries. Because of this convexity, bogs are vulnerable to artificial drainage, and mapping them is important to evaluate whether and how to protect or restore their carbon stocks. Recently, we showed that hydrological constraints create a pattern in the morphology of bogs that holds under a broad range of conditions, as illustrated by eight examples of bogs from northern, through tropical and further to southern latitudes. Specifically, we found that if bog surface elevation, mean water table elevation and transmissivity are related to one another in similar ways across a bog, the relationships among these variables define a bog-specific monotonic function that generates the bog morphology from a solution to Poisson’s equation. This pattern is like a signature for raised bog morphology, and could be used to help identify the boundaries of raised bogs. In addition, the pattern can be used to infer the full morphology of bogs from limited data, which in turn enables estimation of a bog’s stock of vulnerable carbon. We discuss how these findings can be combined with field and remote sensing data to better map the extent and vulnerable carbon stocks of raised peatlands around the world.
Observed multi-scale variations of subglacial hydro-mechanical conditions at Kongsvegen, Svalbard.
Authors: Bouchayer Coline , Nanni Ugo , Lefeuvre Pierre-marie , Hulth John , Schmidt Louise steffensen , Kohler Jack , Renard Francois , Schuler Thomas vikhamar
Published: March 2024

Glacier flow variations are predominantly due to changes at the ice-bed interface, where basal slip and sediment deformation drive basal glacier motion. Determining subglacial conditions and their responses to hydraulic forcing remains challenging due to the difficulty of accessing the glacier bed. In this study, we analyze data series from instruments placed at the base of Kongsvegen glacier (Svalbard) thanks to a 350 m borehole.The borehole was instrumented witha pressure sensor, seismometers, and a ploughmeter to monitor the interplay between surface runoff and hydro-mechanical conditions. Covering the two ablation seasons of 2021 and 2022, , we measured point-scale subglacial water pressure and till strength, and we derived at a kilometre scale the subglacial hydraulic gradient and radius from seismic observations.. Across seasonal, multi-day, and diurnal time scales, we compared these measurements to characterize the variations in subglacial conditions caused by changes in surface runoff. We discuss our results in light of existing theories of subglacial hydrology and till mechanics. We find that during the short, low intensity melt season of 2021, the subglacial drainage system evolves to accommodate runoff variations, increasing its capacity as the melt season progressed. In contrast, during the long and high intensity melt season of 2022, the subglacial drainage system evolved transiently to respond to the abrupt and large water supply. We suggest that in this configuration, the drainage capacity of the hydraulically active part of the subglacial drainage system is exceeded, promoting the expansion of hydraulically connected regions and local weakening of ice-bed coupling, thus enhancing sliding. Our in-situ, multi-method approach provides a unique insight into conditions at the ice-bed interface.
Improving and Assessing Organized Convection Parameterization in the Unified Model
Authors: Zhang Zhixiao , Christensen Hannah , Muetzelfeldt Mark , Woollings Tim , Plant Bob , Stirling Alison , Whitall Michael , Moncrieff Mitchell , Chen Chih-Chieh
Published: March 2024

Improving weather and climate prediction cannot avoid accurately representing organized convection, as its convective and stratiform components distinctly reshape large-scale circulations via redistributing momentum and heat. For latent heating, the stratiform heating in organized convection shifts to higher altitudes compared to convective regions, presenting a significant challenge for representation in models across scales. The Multiscale Coherent Structural Parameterization (MCSP), introduced by Moncrieff et al. (2017), offers a promising solution by generating the top-heavy profile from convective heating in slantwise layer overturning scenarios. As part of the MCS: PRIME project, the PRIME-MCSP implementation by Zhang et al. (submitted, 2024) couples MCSP with the CoMorph-A convection scheme in the UK Met Office Unified Model with the following improvements: 1) CoMorph permits unstable air to rise from any height, diverging from the conventional CAPE trigger for deep convection, thereby enhancing continuity and facilitating storm tracking. 2) We activate MCSP selectively for deep mixed-phase clouds, recognizing the limited ability of shallow clouds to produce a stratiform component. 3) We configure the global model runs to include both a fixed convective-stratiform heating fraction and a fraction proportional to cloud top temperature.MCS tracks in ensembles of weather runs show that PRIME-MCSP suppresses cloud deepening and reduces precipitation areas by dampening low-level updrafts. 20-year climate simulations show that PRIME-MCSP improves the precipitation seasonal cycle over the Indian Ocean, while increasing the warm-season wet bias over the Western Pacific. Additionally, PRIME-MCSP intensifies the Madden Julian Oscillation (MJO). The model run using a variable convective-stratiform fraction more accurately represents the MJO frequency and aligns better with reanalysis. Future plans focus on the stochastic representation of stratiform effects, steered by insights from data assimilation increments.
Chemical Weathering of Mafic Sources in Neogene New Guinea as a Control on Global Climate
Authors: Du Yifan , Clift Peter
Published: March 2024

Silicate weathering is recognized as being critical in removing greenhouse CO2 gas from the atmosphere, which offsets the CO2 supplied by mantle degassing during magmatism. In doing so chemical weathering keeps the Earth’s climate in a relative steady state condition. However, where the most important CO2 sink is remains enigmatic. In this work, we analysed deep-sea clastic sediments recovered by International Ocean Discovery Program Site U1485 from the northern coast of Papua New Guinea to understand the evolution of weathering in New Guinea in the last 0.3 Ma. Major element compositions indicate increased chemical weathering. This is consistent with increasing proportions of kaolinite, indicative of enhanced tropical weathering. Sr and Nd isotopes, together with key trace elements indicate increasing erosion from magmatic arc and ophiolite sources. Isotope mixing calculations indicate that most of the sediment is derived from the colliding magmatic arc. Comparison of sediment with onshore bedrock compositions implies that the source terrains have been especially reactive and efficient at removing CO2 from the atmosphere, especially compared to Himalayan bedrocks. Weathering in eastern New Guinea now accounts for ~16% of global CO2 consumption. We argue that this island has played an important role in driving global cooling.
Numerical Simulation of the Contribution of the Longmenshan Fault to the Uplift Mechanism of Tibetan Plateau
Authors: Tao Wei , Shen Zhengkang , Yang Xuhang
Published: March 2024

Tibet Plateau is bordered to the east by the Longmen Shan Fault, adjacent to Sichuan Basin of the stable Yangtze Block. Across the Longmen Shan Fault zone, the topographic differential extends to 5 km, with the deep lithosphere varying by nearly 20 km. In contrast to the large strike-slip faults found within the plateau, the Longmen Shan Fault is an oblique thrust fault that shapes the plateau's boundary, enveloped in a more intricate structural and dynamic environment.The role of the Longmen Shan Fault remains a pivotal point in the ongoing debate regarding the formation of the Tibet Plateau. We have developed a two-dimensional viscoelastic finite element model, encompassing the Longmen Shan Fault, the Tibet Plateau, and the Sichuan Basin on either side. The model simulates, over geological timescales, the thickening process of the Tibet Plateau and the activity of the Longmen Shan Fault under the influence of gravity and the pushing of the Indian plate. The results demonstrate the adjusting role of the Longmen Shan Thrust Fault in the deformation pattern at the eastern edge of the plateau, explaining the difference in the topographic and lithosphere thickness between the Tibet and Sichan Basin. The thrust Longmen Shan Fault not only contributes to cumulative crustal thickening but also plays a role in the thickening of the mid-lower crust and upper mantle viscoelastic media on the Tibet Plateau side.
Biomarker record in the Korea Gap (Ulleung Basin) of the southwestern East Sea since the last glacial period 
Authors: Park Yu-Hyeon , Bahk Jang-Jun , Jang Jun-Ho , Khim Boo-Keun
Published: March 2024

The East Sea, located on the northwest continental margin of the Pacific Ocean, acts an important marine environment sensitive to the global/regional climate change including the East Asian monsoon. GDGT (glycerol dialkyl glycerol tetraether), one of the membrane lipids originated from archaea or bacteria, has been broadly used as a ubiquitous biomarker for the paleoceanogprahic reconstruction. Although the numerous paleoceanographic results in the East Sea have been reported, the GDGT records and its application to the East Sea paleoceanography are still limited. Here we carried out a study of GDGT, testing the applicability of GDGT-derived proxies as a paleoenvironmental indicator and reconstructing the paleoenvironment using a sediment core from the Korea Gap (Ulleung Basin) in the southwestern East Sea. Downcore profiles of GDGT-derived proxies are clearly distinguished in terms of lithology and age, particularly before and after deglaciation. Concerning the seawater temperature reconstruction, the GDGT-derived temperature (TEX86L-temp) change (5~17°C) is larger than alkenone-derived temperature (UK'37-temp) change (11~21°C). Such a different variation between two temperature proxies potentially indicates that they represent the seawater temperature of different water depths. Especially, the TEX86L-temp during the last glacial period was clearly different from the UK'37-temp. The rapid change of TEX86L-temp before and after deglaciation, similar to GDGT[2]/[3], raises the possibility that, in addition to seawater temperature, other factors related to the sea level change may affect TEX86L-temp. Our results suggest that GDGT biomarker record in the Ulleung Basin (southwestern East Sea) is linked to the regional and global change, providing the possible application to reconstruct the paleoenvironmental changes in the East Sea, although care should be taken when interpreting the seawater temperature signal.