bluuebunny/crossref_metadata_2025 huggingface dataset:
Zinc Isotope Study of Baseline Occurrence Patterns and Potential Contamination of Sediments from the Great Lakes Basin
Authors: Junqueira Tassiane , Ferreira-Araújo Daniel , Vriens Bas
Published: March 2024

The Laurentian Great Lakes are a globally unique freshwater resource, playing a pivotal role in public water supply and agriculture, transportation, hydroelectric power, and ecosystem functioning. However, the Great Lakes also have a long history of metal contamination, especially in so-called Areas-of-Concern near urban areas and industrial sites. One major anthropogenic contaminant in the Great Lakes is Zn, derived from point-sources such as metal mining, smelting, and chemical industries, as well as diffuse sources such as fertilizer application or urban runoff, in addition to natural inputs from atmospheric deposition and natural weathering. Disentangling the importance of these geogenic versus anthropogenic sources and processes is critical to improving our understanding of the cycling and environmental fate of Zn in the Great Lakes region.
We examined spatiotemporal variations in Zn concentrations and isotopic compositions, as well as bulk physicochemical and mineralogical properties, of a total of 72 surface sediments and sediment core samples across nearshore-to-offshore gradients and depositional environments with distinct limnological conditions spanning >50 years.
Our results reveal spatial variations in both Zn concentrations (18 to 580 mg/kg) and isotopic compositions across oligotrophic (Lake Huron) to mesotrophic (Lake Erie) environments. Interestingly, the intra-lake heterogeneity is comparable to or higher than the variability observed at the inter-lake (basin-scale) level, with no upstream-to-downstream accumulation being evident. The isotopic signatures of surface sediment, measured as δ66Zn and ranging from -0.09‰ to +0.41‰, suggest a predominantly geogenic source for Zn. Furthermore, an examination of temporal trends in sediment cores from Lake Huron and Lake Erie indicates consistent metal concentrations and Zn isotopic signatures, implying minimal biogeochemical fractionation within the lakes themselves. Across all sediments and both lakes, metal concentrations and isotopes are positively but not very strongly (R2<0.49 overall) correlated to TOC, TN, and TP, but not to chlorophyll a.
In summary, our findings indicate that sedimentation plays a crucial role as a repository for metals in the Great Lakes, exerting significant influence on the distribution patterns of metals throughout the basin. Furthermore, the higher levels of metals at locations with historical contamination remain spatially constrained and do not seem to disrupt the interconnected system of the Great Lakes.
A Study on Vulnerability Maps for Marine Environmental impact Assessment
Authors: Kim Taeyun , Maeng Junho , Kim Eunchae , Kim Tae-sung , Lee Moonjin
Published: March 2024

In Korea, various development projects such as port construction, nearshore wind farms, tidal reclamation, and seawall construction have been taking place along the coast, however spatial information and vulnerability assessment methods for proper environmental impact assessment are lacking. In this study, we categorized four sectors (social environment, protected areas, habitats, and species) to create vulnerability maps on each that can be used for environmental impact assessment. The vulnerability map for the social environment includes spatial information on fisheries, aquaculture, coastal tourism, and port facilities, while the vulnerability map for protected areas is based on international protected areas, marine reserves, and environmental and fishery resource management areas. Habitat vulnerability map is based on data for tidal flats and wetlands, seagrass beds, stop-over sites of migratory birds, and marine protected species habitats. Finally, species vulnerability map was created spatial fish catches and marine bird tracking data. Vulnerability maps for each sector are based on the scores assigned to sector-specific indicators.
Entropy theory-based approach to derive equivalent GIUH
Authors: Goel Anubhav , Srinivas Venkata Vemavarapu
Published: March 2024

Flood hydrographs are desirable at various hotspots in river basins for a wide range of applications such as hydrologic design and risk assessment of water resources systems. However, determining the hydrographs at ungauged locations has always been challenging. Among various approaches available for simulating a flood hydrograph, the synthetic UH (unit hydrograph) approach has attracted the attention of hydrologists for use in ungauged catchments. The approach involves the derivation of UH for the target location’s catchment and convoluting it with an excess rainfall hyetograph specified for the catchment to arrive at a flood hydrograph. The UH can be derived using Geomorphological Instantaneous UH (GIUH). Recently, there has been growth in interest to consider Horton–Strahler (HS) ratio-based equivalent GIUH (E-GIUH) derived using the self-similarity hypothesis for ungauged catchments, owing to its advantages in overcoming uncertainty in HS ratios arising from uncertainty in the choice of a source DEM. The E-GIUH is constructed using a PDF (probability distribution function) that provides an adequate fit to salient points determined from the E-GIUH characteristics (peak flow, time to peak, and base time). The characteristics are derived using empirical relationships considering the catchment’s geomorphology (equivalent HS ratios, length of the highest order stream) and characteristic flow velocity. An issue in analysis with E-GIUH is that its construction involves uncertainty in the choice of PDF. Furthermore, the empirical relationships used with E-GIUH lack a physical basis. This paper proposes an entropy theory-based methodology to account for the uncertainty in the choice of a PDF for the E-GIUH construction. The efficacy of the proposed methodology in simulating flood hydrographs at ungauged sites is illustrated for typical rainfall-runoff events from 10 unregulated catchments ranging in size from 107 – 2000 km2 and located in two river basins along the west coast of India. The hydrographs are compared with those simulated using conventional EGIUH in terms of several performance measures to illustrate the improvement noted with the entropy theory-based methodology.
Development of an approach based on historical Landsat data for delineating Canadian flood zones at different return periods
Authors: Chokmani Karem , Zidi Haythem , El Alem Anas , Gill-Fortin Jasmin
Published: March 2024

The study addresses the need for flood risk anticipation and planning, through the development of a flood zone mapping approach for different return periods, in order to best prevent and protect populations. Today, traditional methods are too costly, too slow or require too many requirements to be applied over large areas. As part of a project funded by the Canadian Space Agency, Geosapiens and the Institut National de la Recherche Scientifique set themselves the goal of designing an automatic process to generate water presence maps for different return periods at a resolution of 30 m, based on the historical database of Landsat missions from 1982 to the present day. This involved the design, implementation and training of a deep learning algorithm model based on the U-Net architecture for the detection of water pixels in Landsat imagery. The resulting maps were used as the basis for applying a frequency analysis model to fit a probability of occurrence function for the presence of water at each pixel. The frequency analysis data were then used to obtain maps of water occurrence at different return preiods such as 2, 5 and 20 years. 
Global Sensitivity Analysis of tephra models for forecasting
Authors: Scott Emmy , Whitehead Melody , Mead Stuart , Bebbington Mark , Procter Jonathan
Published: March 2024

Accurate forecasts are needed to help mitigate the risks of volcanic hazards to society. Current approaches use probabilistic estimates based on sparse data, supplemented with expert judgment, to describe likely future eruption characteristics. These probabilistic eruption characteristics then inform input parameters required by hazard models.This process requires a lot of simulations with varying input parameters to constrain uncertainty around a future eruption’s hazard characteristics. It is also computationally intensive, and the outputs may quantify, but do not reduce eruption uncertainty. As hazard models become increasingly more complex, so do the number of input parameters that need to be estimated, thus increasing the number of sources of uncertainty. As input parameters used for volcanic hazard models are fundamentally uncertain before (and often also after) an eruption, how do they affect the accuracy and utility of forecasts made using these models?This research explores the input space of volcanic hazard models to understand the interactions between model complexity and robustness of hazard model forecasts. We use the exemplar of volcanic ash distribution models Tephra2 and Fall3D at Mt. Taranaki, Aotearoa-New Zealand (30-50% chance of eruption in the next 50 years). Sampling strategies for Tephra2 and Fall3D were developed to ensure that the input parameter space was fully covered and represent real-world values – both through independent and dependent sampling of parameters. For example, plume height is dependent on the amount of mass ejected during an eruption. A Global Sensitivity Analysis is presented here to investigate the input parameters that significantly influence model output variance. This exploration is conducted through the statistical assessment of Sobol’ indices and eFAST (extended Fourier Amplitude Sensitivity Tests) to discern the key parameters that contribute to variations in the model’s outputs. The results also shed light on which inputs are vital to robust short-term and real-time hazard forecasting, and ultimately require better understanding/quantification before an event.
Coupling economic & ecological models - the effect on biodiversity from energy grass production 
Authors: Winberg Josefin , Clough Yann , Larsson Cecilia , Ekroos Johan , Smith Henrik
Published: March 2024

Bioenergy is expected to play a key role in the transition from fossil fuels to renewable energy sources, with biomass from grass and forestry pointed out as some of the main bioenergy sources in Northern Europe. The increased demand for biomass creates incentives for regional biofuel markets, assumed to replace imported biofuels in the substitution of fossil fuels in industries and the transport sector. In our study, we use coupled modelling of economic and ecological systems to investigate the potential landscape-scale impacts on biodiversity from increased production of lignocellulosic biomass for energy purposes in a farm-forest mosaic region in Southern Sweden. As a first step, we use the empirical and spatially explicit agent-based model AgriPoliS (Happe et al., 2006) to predict how profit-maximizing farmers respond to increased demand and price of ley biomass for energy purposes by changed farm structures and land use within a region, in response to. We expect that increased use of ley and grass biomass for energy could have a negative effect on fodder production, which in turn negatively affects dairy and livestock farming, ultimately with negative impacts on biodiversity if semi-natural grasslands (SNG) are abandoned or afforested. The impact on biodiversity from the resulting land-use changes is modelled in a second step, using a countryside species-area relationship model (cSAR) based on existing field data. By coupling the two models, we can predict the ecological impacts of changes in energy policies or markets, to ultimately understand if there are any tipping points for how much grass biomass can be used for energy until we have a decline in SNG and their associated biodiversity.
Roles of Mountains in Dust Storms 
Authors: Pokharel Ashok Kumar , Pokharel Ashok
Published: March 2024

A study of the dust emission, transport, and deposition is very important for understanding of the various health and social impacts on the local human population, biogeochemical cycle, and the global environmental change. The entry of dust into the atmosphere results from the occurrence of different scales of dust storms resulting from the multi-scale atmospheric processes ranging from the synoptic to near meso-scales of atmospheric motion. In this context, to find the causes of severe dust storms that occurred in the past over north-west Africa, central-north Africa, and Middle east we did a research work. In that study, significant roles of mountains (e.g., Atlas Mountains, Tibesti Mountains, and Sarwat Mountains) were found. For instances, there were a cross mountain flows that produced a leeside inversion layer, which facilitated for the imbalance of the exit region of the jet streak, prior to the large-scale dust storm; generation of terrain (i.e., mountains)-induced downslope winds in response to the transition of the atmospheric flow from a subcritical to supercritical state leading to dust storms; and generation of Kelvin waves supported by the mountains that were responsible for organizing the dust storms and wide distribution and transportation of dust away from the mountains. Regarding this, it is also hypothesized here that similar kinds of roles of mountains are also found in other geographical regions of the world, such as West/North/Northwest China and Mongolia where dust storms occur in the lee of the mountains, (i.e., Tien Shan/ Gobi Altai Mountains/ Khangai Mountains) and involve the long-range transport of atmospheric particulate matter originating from dryland areas. Such events are affecting large numbers of people and their environment especially in spring season because East Asia is the one of the most densely populated areas of the world. In this scenario, these kinds of studies will also be beneficial for analyses of roles of the synoptic features, and identification of their dynamical characteristics are important for evaluating different synoptic dust regimes and their development. So, for the current study, based on the severity of dust storms some cases of dust storms, which occurred in the lee of the respective mountains of China and Mongolia in the past, are considered.Keywords: Mountains, Dust Storms, Jet streak, Atmosphere
Initial agronomic benefits of enhanced weathering using basalt: A study of spring oat in a temperate climate
Authors: Skov Kirstine , Wardman Jez , Healey Matthew , McBride Amy , Bierowiec Tzara , Cooper Julia , Edeh Ifeoma , George Dave , Kelland Mike E. , Mann Jim , Manning David , Murphy Melissa J. , Pape Ryan , Teh Yit A. , Turner Will , Wade Peter , Liu Xinran
Published: March 2024

Addressing soil nutrient degradation and global warming requires novel solutions. Enhanced weathering using crushed basalt rock is a promising dual-action strategy that can enhance soil health and sequester carbon dioxide. This study examines the short-term effects of basalt amendment on spring oat (Avena sativa L.) during the 2022 growing season in NE England. The experimental design consisted of four blocks with control and basalt-amended plots, and two cultivation types within each treatment, laid out in a split plot design. Basalt (18.86 tonnes ha −1 ) was incorporated into the soil during seeding. Tissue, grain and soil samples were collected for yield, nutrient, and pH analysis. Basalt amendment led to significantly higher yields, averaging 20.5% and 9.3% increases in direct drill and ploughed plots, respectively. Soil pH was significantly higher 256 days after rock application across cultivation types  (direct drill: on average 6.47 vs. 6.76 and ploughed: on average 6.69 vs. 6.89, for control and basalt-amended plots, respectively), likely due to rapidly dissolving minerals in the applied basalt, such as calcite. Indications of growing season differences in soil pH are observed through direct measurement of lower manganese and iron uptake in plants grown on basalt-amended soil. Higher grain and tissue potassium, and tissue calcium uptake were observed in basalt-treated crops. Notably, no accumulation of potentially toxic elements (arsenic, cadmium, chromium, nickel) was detected in the grain, indicating that crops grown using this basaltic feedstock are safe for consumption. This study indicates that basalt amendments can improve agronomic performance in sandy clay-loam agricultural soil under temperate climate conditions. These findings offer valuable insights for producers in temperate regions who are considering using such amendments, demonstrating the potential for improved crop yields and environmental benefits while ensuring crop safety.
Geometric considerations on planetary surface temperatures
Authors: Roman Sabin
Published: March 2024

We propose a formula for computing the average planetary surface temperatures based solely on the solar irradiance and the bond albedo. The formula is empirically derived from data on Earth, Venus and Titan, and a model is proposed to justify it. We introduce the concept of planetary inner albedo, as a complement to the usual bond albedo. A geometric proof is given for the main finding of the paper, which can be summarized as follows: the ratio of the inner to outer albedo is a constant, related to the universal parabolic constant. Furthermore, we extend the surface temperature formula to gas giants, giving the temperature at which condensates (e.g., of ammonia) start forming within their atmosphere, particularly for Jupiter, Saturn and Uranus. Based on model complexity, applicability and accuracy, the heating mechanism via atmospheric reflectivity (a mirror effect) performs much better than the alternatives.
Release and characterization of micro- and nano-plastic particles from different types of macro-plastics
Authors: Cheng Tao , Saliminasab Somayeh
Published: March 2024

In the environment, plastics are exposed to weathering processes such as mechanical cutting and abrasion, chemical and biological degradation, as well as UV radiation and heat. These processes breakdown larger plastics into smaller pieces and alter the physical and chemical properties of plastics. Most environment micro- and nano-plastics are generated via weathering of larger plastics. Micro- and nano-plastics are often more mobile, bioavailable, and toxic than their larger counterparts due to their smaller size. As a result, contamination of micro- and nano-plastics has become an increasing concern. Although many laboratory studies have been conducted on micro- and nano-plastics to understand their behavior in the environment, most studies were conducted using synthesized, mono-dispersed, polystyrene micro-spheres as surrogate for micro- and nano-plastics in the environment. The polystyrene micro-spheres, however, do not represent well the complex and diverse composition, size, shape, and other physiochemical properties of real-world micro- and nano-plastics. The objective of our research is to fill the gap by studying the micro- and nano-plastics released from macro-plastics including polystyrene (PS), high-density and low-density polyethylene (HDPE and LDPE), polypropylene (PP), and nylon under laboratory-controlled conditions. Plastic sheets or pellets were cut into small pieces, mixed with nano-pure water, heated, and filtered through 1 um membrane to collect fine plastics. Some macro-plastics were also “weathered” using UV radiation or high temperature. Particle concentration measurement showed that substantial quantities of fine plastics (~ 5*10^9 particles/mL) were released from PP and LDPE macro-plastics, moderate quantities were released from PS macro-plastics (~5*10^8 particles/mL), and practically no fine plastics were released from nylon or HDPE. SEM results indicated the fine plastic particles were of irregular shape and poly-dispersed with a size-range of ~100 to 400 nm, while the polystyrene micro-spheres were of spherical shape with a uniform diameter of 100 nm. Zeta-potential of LDPE fine plastics in 3 mM NaCl solution at pH 5 was ~-42 mV, more negative than those of polystyrene micro-spheres (~-25 mV). This study highlights the distinct properties of manufactured polystyrene micro-spheres and fine plastics released from macro-plastics. Results from our study suggest fine plastics released from macro-plastics may better represents the properties of micro- and nano-plastics in the environment.
A vulnerability framework for a global flood catastrophe model
Authors: Lamb Conor , Probyn Izzy , Wing Oliver , Daniel James , Elmer Florian , Haylock Malcolm
Published: March 2024

In recent years the precision and skill of global flood hazard models has increased dramatically. This, alongside developments allowing for hazard model conversion to stochastic event sets and the open-sourcing of catastrophe modeling software, have opened up the possibilities of developing detailed and skillful global flood catastrophe models; assessing not just average risk but also the possible impacts of major flood events and the probability distribution of annual losses. In order to realize these possibilities, it is necessary to develop a global vulnerability framework that appropriately represents the state of the art in vulnerability modeling whilst being flexible to user inputs and faithfully representing uncertainties. Here, we present a framework for implementing a flexible vulnerability module within a global flood catastrophe model. Vulnerability curves are derived for a variety of occupancies (residential, commercial, industrial), for both building and contents losses. The mean loss ratio curves are derived from literature and commercial datasets before being normalized and fit to a family of logarithmic functions of depth, which can be adjusted for varying property characteristics. Uncertainty distributions are parameterised using a 4 parameter beta model and derived from a large insurance claims dataset (~2 million claims). Finally, using the same large claims dataset, we explore the event-level correlation of the quantiles sampled within our uncertainty distribution. Specifically, we evaluate the extent to which the quantiles sampled of the uncertainty distribution, in a Monte Carlo approach, should be clustered for each event. This is vital for correctly estimating the losses from rare, high-impact events and allows for a realistic representation of vulnerability uncertainty in aggregate loss estimates. 
Enhancing Reproducibility in Soil Water Balance Environmental Studies: The WaterpyBal Framework
Authors: Hassanzadeh Ashkan , Vázquez-Suñé Enric , Valdivielso Sonia
Published: March 2024

This research introduces WaterpyBal, a dynamic tool tailored for spatiotemporal modeling of water balance, emphasizing diffuse precipitation and recharge dynamics. WaterpyBal demonstrates adaptability through its incorporation of diverse input datasets and flexible temporal intervals for model simulations. The tool seamlessly integrates critical stages of water balance assessment, encompassing data interpolation, evapotranspiration, and infiltration computations, accounting for soil attributes and urban hydrological intricacies. It delivers comprehensive water budget parameters, including recharge, deficit, and runoff, accompanied by the generation of informative maps, datasheets, and raster archives.WaterpyBal modular architecture establishes a versatile foundation, positioning it as an open-source Python library exclusively dedicated to Soil Water Balance computations. Supporting temporal variations at hourly, daily, and monthly scales, WaterpyBal accommodates a spectrum of data formats, consolidating disparate stages of SWB calculations into an integrated library. Leveraging the NetCDF data format, widely recognized in scientific toolsets, WaterpyBal streamlines the workflow from spatial interpolation to result visualization, enhancing its applicability across diverse environmental investigations.User engagement is facilitated through the WaterpyBal Studio, an intuitive graphical interface that guides users through each stage of the modelling process. WaterpyBal Studio has a user-centric design and is efficient in supporting sustainable groundwater management initiatives.In summary, WaterpyBal and WaterpyBal Studio emerge as an inclusive solution for water balance modelling, embodying an integrated approach and adhering to the principles of open-source methodologies in environmental research.
Assessment of drought prone areas in Slovakia according to the changes in the long-term mean discharges
Authors: Jeneiova Katarina , Blaskovicova Lotta , Kotrikova Katarina , Danacova Zuzana , Poorova Jana
Published: March 2024

The assessment of changes in the hydrological regime under the climate change uncertainty is especially important for the decision making processes as the hydrological design values, derived for a reference period, are directly used for decision making in many areas of water management, including drought management. Recent local studies confirmed that there are changes in hydrological regime of the last decades in comparison to the currently used reference period 1961-2000 in Slovakia. Therefore, the selection of the reference period for the design values is under revision. In the first step, long-term mean discharge observations from the state hydrological network with near natural regime were analysed. The newly proposed period 1991-2020 was compared to the reference period 1961-2000 and the deviations of long-term discharges in selected water-gauging stations were assessed. The newly proposed reference period was selected for the analysis, as it is recommended by the World Meteorological Organisation for the purpose of climate change monitoring and better comparability of climatological and hydrological characteristics. As the second step, maps of the drought prone areas were drawn according to the spatial distribution of the results. We hope that this analysis will serve as supporting material to help the decision makers in policy making process and toward more effective drought management in Slovakia.
The coronal braiding structures detected in the machine-learning upscaled SDO/AIA images
Authors: Bi Yi
Published: March 2024

we show the evolutions of the separated strands within the apparent single coronal loops observed in Atmospheric Imaging Assembly (AIA) images. The loop strands are detected on  the upsampled AIA 193 images, which are   generated using a super-resolution convolutional neural  network, respectively. The architecture of the network is designed to map the AIA images to unprecedentedly high spatial resolution coronal images taken by  High-resolution Coronal Imager (Hi-C) during its brief flight. At some times, pairs of individual strands appeared to braid with each other and subsequently evolved to become pairs of almost parallel ones with their segments having exchanged totally.  These evolutions provide  morphological evidence supporting occurrences of magnetic reconnections between the braiding strands, which are further confirmed by  the occurrences of the transient hot emissions (>5 MK)  located at the footpoints of  the braiding structures. 
Global sea surface air pressure observations with V-band O2 differential absorption radar
Authors: Lin Bing , Mclinden Matthew Walker , Cai Xia , Heymsfield Gerald M. , Privé Nikki , Harrah Steven , Li Lihua
Published: March 2024

Observed meteorological data are essential for initialization, adjustment, assimilation, and prediction of numerical weather prediction (NWP) models and influence daily activities of people and society. Many key weather variables such as temperature, humidity and winds are well observed globally by combined surface weather stations and suborbital and orbital remote sensing platforms of current Earth Observing System (EOS). However, sea surface air pressure is a significant observational gap in the current EOS. There is no operational remote sensing method available for this crucial dynamic variable of the Earth’s climate and weather systems. Over open oceans, the pressure can only be observed by in-situ sensors of very limited buoys, ships, and oceanic platforms. Studies find that accurate sea level pressure (SLP) measurements can significantly improve not only dynamics but also thermodynamics, such as temperature fields of NWP models [1]. Weather forecasts, especially severe weather predictions including hurricanes, can also be improved considerably with pressure measurements.This study presents the SLP retrieval with emphasis on the evaluation of potential impacts of instrumental and environmental uncertainties on the retrievals for measurements of V-band O2 differential absorption radar systems operating at three spectrally even spaced close frequency bands (65.5, 67.75 and 70.0 GHz). This study finds that precise knowledge on instrument attitude in current design will result in negligible retrieval errors. The spectral control of the instrument and the knowledge on frequency changes will provide accurate information for forward radiative transfer calculations and then, SLP retrieval. Furthermore, the retrieval algorithm combining all three channels, i.e., the 3-channel approach, can effectively mitigate major atmospheric (e.g., water vapor and cloud) and sea surface influences on sea surface air pressure retrieval.The major uncertainty for sea surface pressure retrieval is caused by the noise in radar power returns for the current design. Analysis demonstrates the potential of global SLP observation with error similar to that of marine in-situ measurements (about 1 ~ 2 mb), which is urgently needed for improvement of NWP models. Currently, NASA is developing an airborne system for demonstration of space applications.  Our presentation will provide more details on the system, SLP retrieval and their applications. Reference[1] Prive, N., M. Mclinden, B. Lin, I. Moradi, M. Sienkiewicz, G. Heymsfield, and W. McCarty, “Impacts of marine surface pressure observations from a spaceborne differential absorption radar investigated with an observing system simulation experiment”, J. Atmos. Oceanic Tech., 40, 897 – 918, 2023.
Simulating the exchange of carbon in Canadian pristine, disturbed and restored peatlands
Authors: Roulet Nigel , He Hongxing
Published: March 2024

Approximately 1.19 x 106 km2 of Canada is covered by peatlands containing over 110 to 150 Gt C.  Most are relatively pristine.  A tiny area (~ 0.21 x 106 ha) of Canadian peatlands is affected by land-use change.  The most common land disturbances are due to agriculture, fossil fuel and mineral exploration and extraction, and the creation of hydroelectric reservoirs.  A small area of peatlands (~350 km2) is disturbed by peat extraction for use in horticulture.  We have simulated the emissions of CO2 from pristine, extractive and restored peatlands using the Coupmodel.  Coupmodel reproduces the exchanges of energy, water and carbon well for pristine peatlands and shows their sensitivity to changes in water storage.  We have also successfully simulated the emissions from peatlands that are undergoing extraction.  Our results show that extraction converts a peatland from a sink of ~ 20 to 100 g C m-2 yr-1 to a source of ~ 150 – 200 g C m-2 yr-1.  Finally, we have simulated peatlands that have been restored using ecological approaches (e.g. the moss transfer technique).  They return to being a sink in the same range of undisturbed peatlands 14 years after restoration.  The sink strength is a function of water table depth.  Simulations also show that the restored peatlands are relatively insensitive to climate change over the projected conditions for the next one hundred years.  The key to successfully simulating the carbon dynamics of pristine and disturbed peatlands is to be able to simulate the hydrological and thermal conditions well.  We demonstrate Coupmodel’s capabilities against measurements from pristine, disturbed and restored peatlands.   Simulating the biogeochemistry beyond the range of measurements can provide insight for emissions accounting, climate-smart management, and land-use decisions. 
Triassic-Jurassic ophiolites of Dinaridic Ozren and Borja-Mahnjača massifs in Bosnia and Herzegovina: Mineralogy, geochronology, and P-T estimates from subducted sole
Authors: Putiš Marián , Nemec Ondrej , Ustalić Samir , Sláma Jiří , Balen Dražen , Babajić Elvir , Soták Ján , Ružička Peter
Published: March 2024

The Ozren and Borja-Mahnjača ophiolite complexes in Bosnia and Herzegovina are part of the Dinaridic Triassic-Jurassic ophiolite belt (Putiš et al., 2022; Minerals). Triassic oceanic crust was dated at 242±1 Ma from a relic zircon population in a plagiogranitic layer of partially melted eclogitic sole by LA-ICP-MS U-Pb method, while the main zircon population of 176±1 Ma dates the crystallization of this layer from a metamorphic-anatectic melt. The host sole (Cpx-Grt-Rt) eclogite yielded metamorphic, most likely exhumation zircon age of 168±5 Ma, while rutile gave an age of 165±3 Ma. Jurassic lower oceanic crust was dated from an isotropic gabbro (178±1 Ma, zircon) and plagiogranite (177±1 Ma, zircon). The mantle spinel lherzolites, harzburgites, and dunites are crosscut by Cpx-Pl and Amp-Pl gabbroic, gabbro-pegmatitic, leuco-gabbroic (174±1 Ma, zircon), and doleritic (174±5 Ma, apatite) dykes, all suggesting an advanced evolutional stage and a shallower level of ophiolites due to extension and the deeper mantle melting. The upper oceanic crust pillow basalts are alternating with Bajocian to Callovian radiolarites (~171-162 Ma; Ustalić, Soták et al., 2023; Newsletter of the Slovak Geological Society). The dated N-MORB type sole eclogites-amphibolites indicate the intra-oceanic subduction of the Triassic gabbroic oceanic crust to about 55-60 km that was estimated from Perple_X modelling of 1.9-2.1 GPa and 780°C. Partial melting of subducted slab and a mantle wedge initiated the formation of Jurassic supra-subduction ophiolitic complex detected at ~178-162 Ma. Inferred slab roll-back enhanced the sole extension exhumation between ~170-160 Ma that was coeval with the formation of the upper oceanic crust basalt-radiolarite section. The mineral chemistry-based discrimination diagrams of ultramafic rocks constrain an evolutional trend from MORB to supra-subduction types of ophiolites. An increased depletion of ultramafic rocks is indicated by an increase of Cr# in spinel from ~30 to 60, exceptionally to 75, suggesting transitional abyssal to supra-subduction peridotites and dunites. Relatively thin, often hydrated (Amp-rich) gabbro-dolerite layer of this ophiolite complex may have formed in a fore-arc/back-arc slow-spreading ridge. Ophiolitic breccia, with fragments of the Jurassic oceanic crust and rare Triassic radiolarites, indicates the closure of the Jurassic Neotethys from approximately 160 Ma.Funding from The Slovak research and development agency projects (APVV-19-0065, APVV-20-0079, APVV-22-0092), VEGA agency (1/0028/24, 2/0012/24), and the RVO67985831 program is acknowledged.
Late Holocene lake ecosystem change and the Southern Hemisphere Westerlies on sub-Antarctic Macquarie Island
Authors: Deng Yuqiao Natalie , Roberts Stephen J. , Saunders Krystyna M. , Perren Bianca
Published: March 2024

The Southern Hemisphere Westerlies (SHW) are the world’s strongest zonal surface winds, and they profoundly influence ocean-atmospheric CO2 exchange, southern mid-latitude precipitation patterns and ocean-cryosphere dynamics. Stronger and more poleward-shifted SHW over the last few decades have been linked to anthropogenic warming and increased Southern Ocean ventilation and CO2 outgassing. A more in-depth understanding of past natural SHW variability is required to investigate the SHW response to future, anthropogenically impacted climate change scenarios (e.g., IPCC2023). Macquarie Island (54°30’S, 158°57’E) is located in the Southern Ocean within the SHW core belt, providing an ideal location for reconstructing past changes in the SHW. A strong and decreasing west-east conductivity gradient exists in lakes across the island due to the input of westerly wind-blown sea spray. Moreover, since diatom species present in surface sediments from these lakes are strongly determined by conductivity, we reconstructed variations in the SHW over the last 3000 years using a sediment record from Lake Tiobunga on the west coast. Decreases in the sediment accumulation rate and the dominant, low-conductivity Psammothidium taxa imply that the SHW over Macquarie Island were relatively stronger between ~3000–2300 cal BP and in the last thousand years. Conversely, an increase in Psammothidium taxa implies weaker SHW ~2300–1000 cal BP. Superimposed on these longer-term trends are centennial-scale fluctuations and a dramatic increase in diatom production after 1900 CE, which we associate with the well-documented invasive rabbit infestation. Our results provide a record and improve the understanding of the complex SHW atmospheric system for the last few millennia in the Pacific sector of the Southern Ocean.
Future volcanic eruptions delay stratospheric ozone recovery
Authors: Chim Man Mei , Aubry Thomas J. , Abraham Nathan Luke , Schmidt Anja
Published: March 2024

At present, volcanic sulfate aerosols can lead to stratospheric ozone loss under the presence of anthropogenic chlorofluorocarbons (CFCs). Recent satellite measurements showed that the 2015 Calbuco eruption, a small-magnitude eruption in Chile with 0.4 Tg of stratospheric sulfur injection, caused large-scale stratospheric ozone depletion during October 2015 in the Antarctic. According to the World Meteorological Organization, atmospheric CFC levels have declined since the 1980s, and the Antarctic ozone hole is expected to be healed by around mid-century. In the absence of CFCs, future volcanic eruptions producing stratospheric volcanic sulfate aerosol are expected to increase stratospheric ozone column concentrations. However, it remains uncertain whether future volcanic eruptions will lead to an earlier or a delayed recovery in stratospheric ozone back to 1980s levels.To investigate how future volcanic eruptions affect stratospheric ozone recovery, we generated stochastic future eruption scenarios based on an array of bipolar ice cores, satellite measurements and geological records. We then selected the low-end, median and high-end future stochastic scenarios to perform simulations from 2015 to 2100 using a plume-aerosol-chemistry-climate modelling framework, UKESM-VPLUME with interactive volcanic aerosols. Our model results show that future volcanic eruptions can delay the recovery of the global stratospheric ozone column, as opposed to a previous modelling study that suggested future eruptions will lead to an earlier recovery of the global stratospheric ozone column. In addition, our stochastic scenarios show that future eruptions can potentially delay the recovery of Antarctic total ozone column by 2 to 3 years, depending on the timing, magnitude and latitude of the eruptions. Our results offer insights into the role of future volcanic eruptions in affecting global and polar stratospheric ozone recovery. We also highlight the importance of incorporating interactive volcanic sulfate aerosols in future modelling studies to assess the impact of volcanic eruptions on stratospheric ozone.
New (U-Th-Sm)/He low-temperature apatite and zircon thermochronology ages reveal episodic Tertiary exhumation and uplift of the Central Taurides, southern Turkey
Authors: Aygül Mesut , Uysal I. Tonguc , Sobel Edward R. , Okay Aral I. , Glodny Johannes
Published: March 2024

We performed (U-Th-Sm)/He apatite and zircon thermochronology (AHe and ZHe, respectively) on basement rocks from the Central Taurides, southern Turkiye to constrain its Tertiary >2000m surface uplift history. The samples were collected from the Alanya and Antalya units exposing in the southern part of the Central Taurides. The Alanya Massif represent a Late Cretaceous HP/LT eclogite to blueschist facies metamorphic pile whereas the Antalya Unit shows a relatively coherent stratigraphy consisting mainly of Triassic sandstones together with Permian and Jurassic limestones that are exposed as tectonic windows below the Alanya Massif. The AHe ages from the Alanya Massif cluster in with Early Oligocene (ca. 30 Ma), Early Miocene (ca. 20 Ma) and Late Miocene (ca. 8 Ma) ages. Apatites from one of the sandstone samples from the Antalya Unit gave also a Late Miocene age (ca. 9 Ma), consistent with the cooling ages of the tectonically overlying metamorphic rocks. In contrast, apatites from a sandstone sample exposed in the north show old, dispersed ages suggesting that they escaped from tectonic burial during the Eocene nappe stacking. ZHe ages from one of the metamorphic samples gave a ca. 30 Ma age; indistinguishable from its apatite ages. Our new AHe and ZHe age data indicate that, during Late Eocene nappe tectonics, the Alanya Massif and the underlying Antalya Unit was buried enough to reset the AHe and ZHe ages. Following the compressional regime, during the Early Oligocene, the Alanya Massif was subjected to a fast exhumation, possibly through an extensional detachment. This post-contractile-tectonic exhumation continued episodically during the Early Miocene until just prior to the Miocene transgression. The final Late Miocene exhumation ages are noteworthy and overlaps well with the beginning of the surface uplift of the southern margin of the Anatolian plateau. The new thermochronological data from the Central Taurides suggest that the extension of the southern margin of the Anatolian Plateau had already started in the Early Oligocene, predating the Arabia-Anatolia collision. The extension could have been triggered by the roll-back of the until then intact Bitlis-Cyprus-Hellenic slab, which created a widespread Oligo-Miocene extensional regime on the overriding Anatolian margin.
A new 0.5° x 0.5° REACHES-LME reanalysis temperature dataset for East Asia since the 14th century
Authors: Sun Eric , Huang Hsin-Cheng , Lin Kuan-Hui Elaine , Tseng Wan-Ling
Published: March 2024

To understand and reconstruct paleoclimate, historical records are commonly used. In this study, we utilize the REACHES (Reconstructed East Asian Climate Historical Encoded Series) data, derived from Chinese historical documents, to derive new 0.5o x 0.5o latitude/longitude reanalyais temperature data since the mid-14th centuries. The REACHES reconstructed temperature index (four-point ordinal scale from -2 extreme cold to 1 warm) data covers more than 1,400 sites in the east China. But it has a significant flaw in a large number of missing values most likely reflecting normal weather (index value 0) and so produced a very biased and skewed distribution. To enhance the prediction for the missing data and improve REACHES data quality, we apply simple kriging to impute the missing data and set the mean of the underlying spatial process to zero (normal weather) to adjust for the missing patterns. To improve climate reconstruction accuracy in China, we propose a data assimilation approach by combining the REACHES reconstructed temperature index data with Last Millennium Ensemble (LME) reanalysis data. We propose a nonstationary time series model for the LME data and apply regularized maximum likelihood with a fused lasso penalty for parameter estimation. We treat the resulting distribution as the prior for historical temperatures, which are then updated to acquire refined temperatures based on the REACHES data using the Kalman filter and smoother. Overall, our approaches, which combine historical climate records, climate models, and statistical techniques, provide insights into past climate variations and enhance the accuracy of historic temperature estimation in east Asia.
 
Increased future ocean heat uptake constrained by Antarctic sea ice extent
Authors: Vogt Linus , de Lavergne Casimir , Kwiatkowski Lester , Sallée Jean-Baptiste , Frölicher Thomas L. , Terhaar Jens
Published: March 2024

The ocean is the major sink of excess heat from anthropogenic climate change, and has so far prevented global warming from already surpassing the limits set by the Paris Agreement. This warming of the ocean impacts metabolic processes in marine species and causes sea level rise, more frequent extreme events, and ocean deoxygenation. The current generation of Earth system models has large uncertainties in projections of historical and future ocean heat uptake. Reducing this uncertainty is paramount for informing climate mitigation and adaptation measures.Here we demonstrate that the amount of future global ocean heat uptake is strongly linked to present day Antarctic sea ice extent, so that satellite observations of sea ice can be used to reduce the uncertainty of future ocean heat uptake. Antarctic sea ice extent serves as an indicator of the baseline climate state of the Southern Ocean, and is linked to ocean heat uptake through hemispheric-scale cloud feedbacks. Climate models typically simulate insufficient Antarctic sea ice, a warm bias in Southern Ocean surface temperatures and insufficient Southern Hemisphere low cloud concentrations, negatively biasing future ocean heat uptake. Using present day Antarctic sea-ice extent observations as an emergent constraint allows to reassess the cumulative ocean heat uptake from 2024 to 2100 under a high-emissions scenario, yielding an increased estimate with reduced uncertainty of 2596 ± 216 ZJ.Our findings indicate that ocean heat uptake and its associated impacts will likely be greater than previously estimated, and underline the climatic significance of recent observed changes in Antarctic sea ice, which may foreshadow changes in oceanic and atmospheric warming rates.
Neotectonics in southern Ontario: Pop-up structures and their implications for seismic hazards in intraplate settings
Authors: Clark Abigail , Peace Alexander , Eyles Carolyn , Davies Ethan
Published: March 2024

Intraplate neotectonism is generally not well documented and understood despite its significance for seismic hazards in areas such as eastern Canada. This study aims to provide an in-depth structural analysis of potential neotectonic pop-up structures in southern Ontario, Canada, leading to a more comprehensive definition of pop-up structures, and ultimately constrain the processes involved and extent to which neotectonism impacts the region. Three locations in Southern Ontario were documented using a combination of ground and drone-based structural analysis: 1) Fletcher Creek Ecological Preserve, 2) Wainfleet Wetlands, and 3) multiple sites on Manitoulin Island. Sites were chosen where previous work had documented neotectonic activity, and/or where initial geomorphic analyses indicated the possibility of pop-up structures. The locations are all located within the Ordovician to the Devonian Niagara Escarpment stratigraphy. Fracture patterns at each site were analyzed using ground-based measurements or drone-based photogrammetry (DJI Phantom 4 V2 and Phantom 4 Pro acquisition followed by analysis in Pix4D), where applicable. Orthomosaics were then analyzed using FracPaq to determine fracture statistics including orientation, intensity, and density. Where access permitted, ground-based structural measurements were also obtained on structures such as fractures and folds, in addition to RTK-DGPS (real time kinematic differential-global positioning system) profiles over potential pop-up structures. The analysis revealed inconsistencies in the definition of a "pop-up", prompting further inquiry into the definition of a pop-up versus stress relief features more generally. To address this ambiguity, a classification system was developed to differentiate between pop-ups and other tectonic stress relief features. It was concluded that pop-up structures exhibit a distinct geomorphic expression, manifesting as a linear elevated ridge. In southern Ontario, regardless of whether a feature is identified as a stress relief feature or a pop-up, it nonetheless demonstrates that the region is tectonically active despite often being characterized as a stable continental interior. This study adds to a growing body of work documenting neotectonic activity in southern Ontario, with the several stress-related structures documented for the first time in this study showing their prevalence over a wide area.