bluuebunny/crossref_metadata_2025 huggingface dataset:
R&I solutions and Blue Culture Technology Hubs supporting Underwater Cultural Heritage research
Authors: Stergiopoulou Lydia , Manglis Angelos , Raxis Polyvios , Krinidis Stelios
Published: March 2024

This work presents the framework of BCT Hubs project that operates in the space of Blue Culture Technologies (BCT) supporting the Underwater (UW) Cultural Heritage (CH) scientific research. The development of BCT Excellence Hubs and their promoted R&I solutions support, as regional ecosystems, the sustainable protection, restoration, valorization, management, and accessibility of UWCH by consolidating capacities of public sector, research/academia, NGOs, and business stakeholders. An innovative framework is under development that combines sensors information with navigational data and GIS-based software to provide high-quality 3D/4D UW representations. These R&I services will be linked to virtual reality (VR) technologies improving on-site and remote accessibility to UWCH via dry-dive; as well as to an augmented reality (AR) app that based on sensing solutions can augment diving capability. Ongoing additional developments combination of the 3D/4D models with real-time streams and AI algorithms aiming at detecting looting or degradation of UW assets.  The development of the BCT Excellence Hubs in Greece, Malta, Bulgaria aims at the establishment of regional ecosystems, where R&I actors will offer access to excellence, knowledge transfer and development of entrepreneurial skills. The technical support needed, as well as the digital maturity level of the Blue Culture value chain of the ecosystems will be analysed and assessed, towards receiving tools and support with respect to their UWCH missions. Overall aim is the management of UW heritage under threat, UW documentation, archaeological excavation, safeguarding, promotion and accessibility.
Microplastic particles resuspensions in bare soils and global atmospheric transport
Authors: Evangelou Ioanna , Tatsii Daria , Bucci Silvia , Stohl Andreas
Published: March 2024

Microplastics (MPs), which are synthetic polymer particles with sizes from 1 µm to 1 mm, are considered as an emerging pollutant. It has been proposed that the atmosphere has a significant role in the transport of MPs. Atmospheric MPs can originate from primary sources, such as population activities, or secondary sources, like the ocean and soils.In this study, we estimate the secondary MPs that are resuspended in bare soils together with mineral dust, using measurements of MP soil mass fractions, the MP enrichment in wind-eroded sediments relative to the original soil, and spatiotemporally resolved dust emissions calculated with the dust mobilization scheme FLEXDUST (Groot Zwaaftink et al., 2016). Using the Lagrangian atmospheric dispersion model FLEXPART (Pisso et al., 2019), we simulate the global transport of resuspended MPs for a range of sizes and morphologies (spheres, fibers) based on our estimated emissions. We perform a ten-thousand-member Monte Carlo (MC) simulation in which the parameters affecting the resuspensions are perturbed, and an extended MC by varying further the assumed MP size distributions to estimate the resuspension and transport uncertainties, respectively.
SAR Monitoring and Finite Element based Stability Modeling for the Zero Landslide in the Darjeeling Himalayas, India
Authors: Das Suvam , Pandit Koushik , Kanungo Debi Prasanna , Sarkar Shantanu
Published: March 2024

Landslides are one of the recurring geological hazards in the Indian Himalayas, often leading to loss of life and economy. For the present study, the Zero landslide located in the Darjeeling Himalayas, India has been investigated. This landslide was first activated on July 16, 2014 and its subsequent occurrences have affected a total area of 1×105 sq.m. Field investigations revealed that a local school building, its nearby roads and a few residential buildings are at risk from this landslide. Therefore, monitoring and stability modeling becomes imperative to assess the associated hazard level. For the studied case, the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique was applied to monitor the surface level deformation. For this purpose, Sentinel-1 SLC images captured from January 2022 to November 2023 were collected, and processed using the HyP3 and OpenSARLab platforms. The SBAS-InSAR results revealed maximum subsidence i.e., Line-of-Sight (LOS) velocity (cm/y) of –8.2 and –11.5 for ascending and descending orbit directions, respectively. The presence of transverse tension cracks in the crown and flanks of this landslide supports the SBAS-InSAR results and indicate an active sliding. Furthermore, to assess the slope stability, continuum based two-dimensional finite element modeling (FEM) was carried out. For this, the Shear Strength Reduction (SSR) method was employed in the FE analysis to compute the safety factors for different scenarios. To incorporate material properties within the configured FEM, the Mohr-Coulomb strength criterion was used for soil overburden, and the Generalized Hoek-Brown strength criterion was used for bed-rock profile. The FE analysis revealed a critical Factor of Safety (FoS) value of 1.07 for dry condition and 0.78 for wet condition (Ru). The obtained FoS values suggest that the studied slope section is marginally stable in dry condition; however, instability may be induced during a rainfall event in future. Based on these findings, the design and implementation of landslide risk mitigation measures have been encouraged prior to any major landslide event at the study location.
Shifts in the peak vegetation growth over Tibetan Plateau
Authors: Liu Dan , Meng Fandong , Xu Chaoyi , Wang Tao , Piao Shilong
Published: March 2024

Understanding the seasonality of vegetation growth is important for maintaining sustainable development of grassland livestock systems over the Tibetan Plateau (TP). In this study, we investigate the shifts of the date of peak vegetation growth and its climatic controls for the alpine grasslands over the TP during 2001–2020. The date of peak vegetation growth over the TP advanced by 0.81 days decade-1 during 2001–2020. This spring-ward shift mainly occurs in the semi-humid eastern TP, where the peak growth date tracks the advancing peak precipitation, and shifts towards the timing of peak temperature. Through analyzing the synchrony of peak vegetation growth and climatic peaks, we showed that 26% of the semi-humid eastern plateau is shifting from thermal-constrained ecosystem towards water-constrained ecosystem. The advancing peak growth over the eastern TP could significantly stimulate GPP, but this positive effect is weakened from 3.02 gCm-2 year-1 day-1 during 2000s to 1.25 gCm-2 year-1 day-1 during 2010s. Our results highlighted the importance of water availability in vegetation growth over the TP, and indicated that the TP grassland is moving towards a tipping point of transition from thermal-constrained to water-constrained ecosystem under a rapid warming climate.
Comparative assessment of VOS and model wind waves over the global oceans accounting for sampling effects
Authors: Sharmar Vitali , Grigorieva Vika , Gulev Sergey
Published: March 2024

Validation of the global model long-term wind wave hindcasts against wave observations from Voluntary Observing Ships (VOS) are of a high demand, as VOS observations provide separate estimates of wind sea and swell for a long period of about several decades. However, VOS data suffer from spatial and temporal inhomogeneity of sampling and direct comparisons with model output are difficult as there is no way of quantifying differences associated with model setting and with sampling uncertainties. In this study, we perform a validation of the 40-yr long (1980-2019) wave model hindcast performed with WAVEWATCH-III spectral wave model forced with ERA5 reanalysis against provisionally corrected global VOS wind wave archive, accounting for sampling density in VOS data. For this purpose, model output was subsampled according to the VOS observations using the space-time collocation technique. This allows for estimating the total sampling uncertainty of significant wave heights (SWH), wind sea and swell. Further, this allows for comparison of model data with VOS observations which is not influenced by sampling biases.Sampling uncertainties in SWH are largely driven by sampling uncertainties in the wind sea, being quite close to each other. Total sampling error variability in SWH and wind sea provide considerable reduction of uncertainties along the major ship routes where sampling errors drop by several times compared to the areas outside of the dense ship traffic. The smallest sampling uncertainties are identified in the North Atlantic subtropics where relatively weak short-term variability of wind waves is collocated with the moderately high sampling associated by dense ship traffic between Europe and the North America. Estimates of sampling errors are separately developed for sea and swell providing hints on the accuracy of wea and swell portioning in spectral wave model. We also estimated the impact of sampling onto extreme wind waves and this impact regionally is not necessarily correlated with the effect of sampling on means. Finally analysis is performed for patterns of interannual variability, including long-term trends.This study is funded by RSF project # 23-47-00030.
The Impact of Very-Short-Lived Chlorocarbons on Stratospheric Chlorine and Ozone Abundance During 2011-2022
Authors: Liang Qing , Newman Paul , Fleming Eric , Lait Leslie
Published: March 2024

Stratospheric ozone is catalytically destroyed by chlorine released from ozone-depleting substances (ODS), e.g., chlorofluorocarbons, and halogenated very-short-lived substances (VSLS). In addition to chlorine contributions from continued emissions of Montreal Protocol-regulated long-lived ODSs (from existing banks, production, consumption, and feedstocks), recent research has highlighted concern over rapidly growing emissions of dichloromethane (CH2Cl2) - a chlorinated VSLS (Cl-VSLS). Large emissions come from Asia have developed because of fast economic growth. In this study, we have conducted model simulations with geographically resolved surface emissions of the two most abundant Cl-VSLS, CH2Cl2 and CHCl3, with the NASA GEOS Chemistry Climate Model (GEOSCCM). The simulations cover the 2011-2022 period to understand the transport pathway of Asian Cl-VSLS emissions to the stratosphere and to quantify the contribution of Asian emissions to the stratospheric chlorine budget w.r.t. the global estimate during the 2010s. With global emissions of about 1300 Gg/yr in 2020-2022, our results suggest Cl-VSLS adds about 120 ppt Cl to stratospheric chlorine.  The Asian Summer Monsoon plays a dominant role in the troposphere-to-stratosphere transport of Cl-VSLS and is twice as efficient for delivering CH2Cl2 to the stratosphere than the tropics. About 200 ppt of VSLS-Cl gets into the stratosphere during summer 2022 within Asian Summer Monsoon Anticyclone. GEOSCCM simulation results suggest that the overall impact of Cl-VSLS on stratospheric ozone is < 2 DU (0.7%) globally. Interestingly, 2019 features an anomalously large ozone perturbation due to Cl-VSLS. While global ozone changes little, total column ozone decreases by 10 DU in the Antarctic but increases by 15 DU in the Arctic. 
Advancing water resource resilience through agroforestry
Authors: El Garroussi Siham , Wetterhall Fredrik , Barnard Christopher , Di Giuseppe Francesca , Mazzetti Cinzia
Published: March 2024

Future climate change is expected to exacerbate hydrological drought in many parts of Europe, making effective management of water resources more imperative to ensure groundwater sustainability. The EU biodiversity strategy for 2030 suggests a strategic target to turn at least 10% of the EU’s agricultural areas into high-diversity landscape features like hedges and trees. In this study, we investigate how afforestation would affect hydrological conditions in Europe under climate change, focusing on three scenarios: (1) an hypothetical extreme scenario transforming all agricultural land into forests under current climate, (2) a more realistic scenario aligning with the EU biodiversity strategy which envisages converting 10% of the land under current climate, and (3) a scenario involving the conversion of 10% of agricultural land into forests, but under a climate that is 2°C warmer. We use the LISFLOOD hydrological model setup across Europe at a spatial resolution of ~2km forced by gridded observed precipitation and temperature over a time period of 1991-2020 under the current climate scenario. The results were evaluated as changes in evapotranspiration, groundwater levels, and river discharge peaks. The findings from the afforestation scenario indicated a rise in evapotranspiration, higher groundwater levels, and diminished river flow peaks, suggesting an improvement in water sustainability as well as an increased resilience to flooding. This study highlights the hydrological benefits of strategic land use changes, offering key insights for European water resource management and policy formulation in the face of climate change.
The Database of European Forest Insect and Disease Disturbances: DEFID2
Authors: Forzieri Giovanni ,   DEFID2 team
Published: March 2024

Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of biodiversity could be increasingly compromised. Despite the relevance of these detrimental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including severity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite-based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and damage metrics derived from them using the LandTrendr spectral-temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and possible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics and enhance their representation in land-climate models. Further data sharing is encouraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc-opendata/FOREST/DISTURBANCES/DEFID2/.
A weather reconstruction approach for daily precipitation since 1960s in South America 
Authors: Huerta Adrian , Serrano-Notivoli Roberto , Stocker Benjamin , Brönnimann Stefan
Published: March 2024

Long-term weather observations are required to understand past climate and extreme weather events. However, there are a host of factors that affect the measurements and make the data unsuitable for direct use and analysis. In this regard, the proposed research attempts to create a serially complete observed and gridded dataset of daily precipitation in South America, a region with sparse station networks, complex orography (Andes Mountain range) and a diversity of climates (tropical to sub-polar climates). To accomplish this challenging purpose, we will create in a first step a station-based database with high-quality standards using reproducible quality control, gap-filling and homogenisation procedures. In a second step, we will construct a gridded-based dataset by employing weather reconstruction approaches such as analogues plus machine learning together with multiple satellite precipitation products and other remote-sensing- and reanalysis-based variables. Further, we will account for uncertainty in the station- and gridded- based dataset, which is critical for adequately understanding uncertainty in any application modelling chain, especially in complex-sparse terrain regions. Once the gridded data is available, we will evaluate it by analysing extreme events indices in conjunction with other established gridded precipitation products. This analysis will not only evidence the added value of the gridded data but also will enhance the knowledge of high-impact extreme events in South America, particularly over the Andes chain as a whole. Finally, we expect that the data products from the research will be useful for climate science and other geoscientific and operational applications in Earth-system fields in South America. The proposed study will continue previous projects in the tropical Andes (DECADE and CLIMANDES) by the University of Bern as it will expand to the entire continent, providing a wide variety of applications. 
Retrospect of the polygenetic Kagbeni flood event (August 13, 2023) in Mustang, Nepal. Are rapid hydromorphological processes relays and sediment cascades in the catchment well taken into account in the risk equation?
Authors: Fort Monique , Gurung Narayan , Arnaud-Fassetta Gilles , Bell Rainer
Published: March 2024

A severe and complex, polygenetic flood event occurred in Muktinath area of Mustang, Nepal on the evening of August 13, 2023 causing significant damage to property and infra-structures worth approximately of USD 7.4 million at Kagbeni Village, which is nestled along both banks of Kagkhola, a major left bank tributary of the Kali Gandaki River. About 29 houses, 1 motorable bridge, 1 steel truss bridge and 3 temporary bridges were destroyed, while more than 25 cows and other livestock were killed. Fortunately, human lives were spared because the community was warned to move to safety before the mud and sludge hit the village. A study was conducted in order to know what had caused this unusual flash-flood in Mustang. Kagbeni (2810 m) lies in the north Himalayan, rain-shadow area and normally receives few rainfall (
GIRHAF (Gridded hIgh-resolution Rainfall for the Horn of AFrica): a new rainfall product for detailed applications in a region beset by climate hazards
Authors: Rios Gaona Manuel F. , Michaelides Katerina , Singer Michael Bliss
Published: March 2024

Rainfall is one of the most important inputs for applications such as hydrological modelling, water resource allocation, flood/drought analysis, and climatic risk assessments. Currently, there exist numerous (global) products offering rainfall estimates at various spatio-temporal resolutions. Nevertheless, there are still places on Earth where the coverage and/or quality of such products is limited due to sparse ground-control data, thus constraining the robustness of input rainfall for hydrological and climate applications. Located in Eastern Africa, the Horn of Africa (HOA) is a place where climate impacts like droughts and floods frequently inflict a huge toll on the lives and livelihoods of millions residing in subsistence rural communities. For places like this, high resolution rainfall data are fundamental to understanding the availability of water resources, flood hazard, and soil moisture dynamics relevant to crop yields and pasture availability.Here we introduce GIRHAF (Gridded hIgh-resolution Rainfall for the Horn of AFrica), which is a 20-year rainfall product, with a spatio-temporal resolution of 0.05°×0.05°, every 30 minutes. GIRHAF is based on downscaling CHIMES (Climate Hazards center IMErg with Stations) a pentad operational rainfall product which corrects microwave signals in IMERG (Integrated Multi-satellitE Retrievals for GPM -Global Precipitation Measurement mission-) by in situ rain gauging networks. The goal of this product is to offer the HOA region high-resolution rainfall fields that can support more detailed mechanistic analyses of historical rainfall and can also provide the base dataset required to develop stochastic rainfall models capable of simulating forecasted or projected climate scenarios. It is our aspiration that GIRHAF will enable improved responses to climatic hazards as well as better water resources management in the HOA region, and perhaps to allow people of this region to better prepare to future climate scenarios.
Iron fertilization-induced deoxygenation of Eastern Equatorial Pacific intermediate waters during the Paleocene-Eocene Thermal Maximum
Authors: jiang xiaodong , Yao weiqi , zhao Xiangyu , sun Xiaoming , Roberts Andrew , Sluijs Appy
Published: March 2024

Thousands of gigatons (~2500-4500 Gt) of carbon were released into the ocean and atmosphere system over several thousand years during the Paleocene-Eocene Thermal Maximum (PETM, ca. 56 Ma), a transient period of global warming, is considered an important analog for future greenhouse conditions. It was accompanied by a significant carbon cycle perturbation, intensified weathering and hydrological cycling, and ocean deoxygenation. Although ocean deoxygenation across the PETM is reported widely, its mechanism in the open ocean remains uncertain. We here present magnetic and geochemical analyses of sediments from the Eastern Equatorial Pacific (EEP) Ocean. We find that iron fertilization during the PETM by eolian dust and volcanic eruptions fueled EEP ocean productivity. This process led to increased organic matter degradation and oxygen consumption in intermediate waters, leading to deoxygenation. Our findings suggest that iron fertilization could be an important driver of open ocean oxygen loss, as a side effect of global warming. Our observation is important in the emerging discussion of how global warming will reduce dissolved oxygen in the open ocean and, in turn, affect the marine fishery industry and future food security.
Statistically impossible temperatures.
Authors: Wehner Michael , Risser Mark , Zhang Likun , Boos William
Published: March 2024

The 2021 heatwave in the Pacific Northwest of the United States and Canada was unusual in many regards. In particular, not only was the event deemed impossible prior to the human interference in the climate system, standard out-of-sample non-stationary generalized extreme value (GEV) analyses revealed it to be statistically impossible in 2021 as many observed temperatures were above the upper bound of the upper bound of fitted GEV distributions. Obviously, as the event actually occurred, these statistical models are not fit for the purpose of estimating the influence of climate change on the event’s probability.By expanding the number of physical covariates beyond just greenhouse gas concentrations and by incorporating spatial statistical techniques in a Bayesian hierarchal framework, we are able to construct a statistical model where observed temperatures during this heatwave were not “impossible” and thus estimate the change in their probabilities leading to Granger-type causal inference attribution statements.We further extend this statistical framework to all quality daily GHCN station measurements and find that while many physically plausible outlier temperatures are impossible in the simple non-stationary GEV framework, they can be explained using our more complicated non-stationary Bayesian spatial statistical model embedded in a deep learning machinery. 
Projecting the evolution of the Northern Patagonian Ice Field until the year 22
Authors: Schaefer Marius , Tabone Ilaria , Greve Ralf , Fürst Johannes , Braun Matthias
Published: March 2024

The Northern Patagonian Ice Field (NPI), Chile, is the second-largest ice body in the Southern Hemisphere outside Antarctica, and one of the two remnant parts of the Patagonian ice sheet that existed during the last glacial period. It is located in the Southern Andes, a region that was identified to have one of the most negative specific mass balances of the world’s glacierized regions. The NPI is a highly dynamic ice body, characterized by large accumulation/ablation rates and contains the equator nearest tidewater  calving glacier, Glaciar San Rafael. We used the ice-sheet model SICOPOLIS to reproduce the current state of NPI and realize projections under different climate change scenarios. Calving is treated by implementing an additional specific mass loss for grid cells which are in contact with the ocean (San Rafael Lagoon). Forcing the model with a constant present-day surface mass balance a steady state is achieved which shows much similarity with the current state of the NPI. When forcing the model with different climate change scenarios, a mostly constant mass loss during the 21st century and a stabilization of the NPI during the 22st century is observed. The representation of Glaciar San Rafaels' front position improves clearly when implementing a simple (constant) calving law, however, the effect on the projected overall ice volume is low. Our simulation suggest that even if climate stabilized during 21st century, glacier changes on NPI would continue during the 22nd century.
Protolith age and composition of the north Shahrekord Jurassic eclogite in SW Iran: Correlation with the Permian flood basalts across Asia
Authors: Jamali Ashtiani Rezvaneh , Schmitt Axel K. , Hassanzadeh Jamshid , Sharifi Arash
Published: March 2024

The Zayanderud high-pressure metamorphic complex in the Sanandaj-Sirjan zone, north of the Neotethyan Zagros suture in Iran, includes Jurassic eclogites that have been the subject of multiple studies aiming at deciphering their metamorphic history. However, determination of the protolith age has remained ambiguous due to subsequent thermal overprint. This study investigates the protolith ages and characteristics of metabasites from outcrops north of Shahrekord that are older than the Zagros blueschist association. Through U-Pb zircon ages, whole rock analysis, and Sr-Nd-Hf isotope data for metabasites, new insights into their age, chemical composition, and tectonic setting have been achieved. Ion microprobe U-Pb geochronology of rare zircons in thin section permits extracting Early Permian protolith ages for eclogite, despite textural evidence for metamorphic, low-U zircon overgrowths on the zircon crystals. These protolith ages align with the well-studied Permian flood basalts associated with Pangea breakup and Neotethys opening. Remnants of coeval flood basalts are preserved in Oman, the Himalayas, and the Asian Large Igneous Provinces in Tarim, Tianshan, and Emeishan. Elemental and Sr-Nd-Hf isotopic compositions of Zayanderud eclogites and amphibolites confirm a continental flood basalt affinity. Earlier investigations suggested that the eclogitization occurred in the Early- to Middle Jurassic time. Our findings put forward a scenario that the Permian volcanic passive margin of this Neotethyan segment sank into the mantle at the onset of subduction in the Jurassic. The studied example advocates a previously unexplored possibility of deep sinking of a passive continental margin at the beginning of subduction. Another important aspect of the studied metabasites is that they have recorded two major rifting events in the history of Pangea, namely the Permian rifting which caused the separation of the Cimmeria continental ribbon and the Jurassic opening of the southern hemisphere oceans in connection with initiation of subduction within the Neotethys domain.
Modeling of Saturn’s radiation environment
Authors: Drozdov Alexander , Kollmann Peter , Hao Yixin , Wang Dedong
Published: March 2024

A common problem in space physics is how the energetic particles we observe in space are accelerated to high energies. In the magnetospheres and radiation belts of magnetized planets like the Earth and Saturn, we find electrons with up to MeV energies. There are two fundamental acceleration processes. Electrons can gain energy when they are transported closer to the planet (radial acceleration), where the magnetic field is stronger. The alternative is that the electrons are accelerated locally, through fluctuating electric or magnetic fields and wave-particle interaction. In this work, we use a modified version of the Versatile Electron Radiation Belts code to perform the simulations of the radiation belts at Saturn. Using convection terms of a modified Fokker-Planck equation, the zebra stripes and banana orbit signature is reproduced in the convection-diffusion code. Using the flexibility of our simulation framework, we explore the effects of radial diffusion, coulomb scattering and the local diffusion. Throughout the series of simulations, we aim to understand the role of the controlling processes of the radial transport acceleration (e.g., due to variable electric field) and the role of local acceleration, as well as any other processes needed to reproduce the observations.
Controls on the relatively slow thinning rate of a debris-covered glacier in the Karakoram over the past 20 years: evidence from mass and energy budget modelling of Batura Glacier
Authors: Zhu Yu , Liu Shiyin , Brock Ben W. , Xie Fuming , Yi Ying
Published: March 2024

The influence of supraglacial debris cover on glacier dynamics in the Karakoram is noteworthy. However, the investigation of how debris cover affects the seasonal and long-term variations in glacier mass balance through alterations in the glacier's energy budget is scarce. The present study applied an energy-mass balance model coupling heat conduction within debris layers on Batura Glacier in Hunza valley, renowned as the most representative debris-covered glacier in the Karakoram, to demonstrate the influence of debris cover on glacial surface energy and mass exchanges. The mass balance of Batura Glacier is estimated to be -0.262 ± 0.561 m w.e. yr-1, with debris cover accounting for 45% of the mass balance variation. Due to the presence of debris cover, a significant portion of the energy income is utilized for heat conduction within the debris layer, reducing the melt latent heat at the glacier surface. We found that the mass balance reveals a pronounced arch-shaped structure along the elevation gradient, which primarily attributes to the distribution of debris thickness and the impact of debris cover on the energy structure within various elevation zones. Through a comprehensive analysis of the energy transfer within each debris layer, we have demonstrated that the primary impact of debris cover lies in its ability to modify the energy reaching the surface of the glacier. Thicker debris cover results in a smaller decrease in temperature between debris layers and the ice-contact zone, consequently reducing heat conduction. Over the past two decades, Batura Glacier has maintained a relatively small negative mass balance, owing to the protective effect of debris cover. The glacier exhibits a tendency towards a smaller negative mass balance, with diminishing dominance of ablation at the glacier terminus on glacier mass changes. 
The redox state of asthenospheric mantle and the onset of melting beneath mid-ocean ridges
Authors: zhang Fangyi , Lai Shaocong , Stagno Vincenzo
Published: March 2024

The redox state of the convective asthenospheric mantle governs the speciation of volatile elements, such as carbon, therefore influences the depth at which (redox) melting can occur with implications for seismic signals. Geophysical observations suggest the presence of carbonatite melts at depth of 200–250 km, however, thermodynamic models indicate that the onset of (redox) melting would occur at 100–150 km for a mantle with 3–4 % of Fe3+/∑Fe. Here we present a new oxybarometer based on the V/Sc exchange coefficient between olivine and melt, which is insensitive to surficial alteration, volatile degassing, electron exchange reactions and fractional crystallization. By applying this method to primary mid-ocean ridge basalts (MORBs) from the Southwest Indian Ridge and East Pacific Rise, we demonstrate that the average oxygen fugacity (fo2) of MORBs, corrected for the depth of formation, is 0.88±0.24 log units above the fayalite-magnetite-quartz (FMQ) buffer, which is slightly more oxidized than previously estimated (near FMQ buffer). Our findings indicate that the convective asthenospheric mantle exhibits a higher oxygen fugacity than continental lithospheric mantle. Along an adiabat, carbonatitic melts can form from a CO2-bearing source at depth of 200–250 km explaining, therefore, the electrical conductivity and seismic velocity anomaly of the asthenospheric mantle.
Large-scale carbon release from multiple sources caused an Early Jurassic hyperthermal event
Authors: Chen Wenhan , Kemp David , Cui Ying , Li Chao
Published: March 2024

The Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) was one of the most significant hyperthermal events in the Phanerozoic, characterized by a series of climatic and environmental perturbations on land and in the oceans. The climate warming was accompanied by an abrupt negative carbon-isotope excursion (N-CIE) in the biospheric carbon reservoir, suggesting the driver of this event was the massive release of 12C-enriched carbon. However, the source, rate, and cumulative mass of carbon emitted during the T-OAE are poorly constrained, leaving the specific mechanisms of climate change uncertain. Here, we simultaneously assimilate atmospheric pCO2 reconstructions and carbon-isotope data from 24 well-constrained T-OAE profiles in an Earth system model to quantify carbon emission masses, rates, and sources. Our simulations suggest the emission of 10,900 Pg C across the event at rates of up to 0.8 Pg C yr-1. A clear pulse of extremely 12C-enriched carbon release occurred at the onset of the T-OAE, likely indicative of a biogenic (e.g., methane hydrate) source. This was followed by the release of carbon consistent with a magmatic source, with two transient pulses potentially indicative of thermogenic carbon emission superimposed on a protracted input of volcanic carbon. The complex pattern of carbon release revealed by our modeling emphasizes the interplay of both deep and surficial Earth processes in driving the T-OAE event. Negative carbon fluxes characterize the N-CIE recovery phase, underlining the crucial roles of enhanced continental weathering and massive burial of organic carbon in facilitating Earth system recovery from massive warming.
Identification of hydrogeochemical processes through inverse modeling in PHREEQC in Lake Tziscao, belonging to the Montebello lagoon system in Chiapas, Mexico.
Authors: González Herrera Carlos Raúl , García Villanueva Luis Antonio
Published: March 2024

Lake Tziscao is one of the water bodies belonging to Lagunas de Montebello National Park, located in the south-southeastern part of the state of Chiapas, Mexico. Its importance lies in its great tourist activity due to its size and nearby human settlement, which is why there are numerous anthropogenic factors that promote the transformation of natural areas within it.In this work, PHREEQC software was used to perform inverse hydrogeochemical modeling, with which the predominant hydrogeochemical processes of the site were identified and estimated using 20 sampling points distributed along Lake Tziscao.Prior to the execution of the model, a statistical analysis, simplification and graphic representation of samples, as well as a site analysis were carried out, whose comparison results coincide with the presence of calcic-magnesic bicarbonate type waters, suggesting the feasibility of the proposed model.Modeling results indicate that the main processes present in the water-rock interaction in the area are: hydration of anhydrite and subsequent dissolution-precipitation of gypsum in large proportion, minimal transfer or equilibrium in carbonate minerals and halides such as calcite, dolomite, sylvite and halite, nonetheless, the concentrations of elements such as nitrogen and phosphorus within the water body suggest anthropogenic pollution sources, while the relatively low salinity indicates that the waters are poorly evolved or have been transported to a lesser extent.
A turbulent dynamo threshold in the shell-model approximation.
Authors: Abushzada Ilyas , Yushkov Egor
Published: March 2024

Turbulent magnetic dynamo models were created about fifty years ago to describe the growth of the average magnetic energy in random convective plasma flows. A typical feature of such models is the generation threshold, when the exponential growth of magnetic energy begins only at sufficiently large magnetic Reynolds numbers Rm. In particular, one of the first models, proposed in the 70th by Kazantsev and Kraichnan, predicts a generation threshold in the region of Reynolds numbers of the order of 100. This threshold is difficult to achieve even for modern laboratory experiments, and therefore many studies in recent years have been devoted to clarifying this critical value. However, there is a sufficient disadvantage of usually used turbulent dynamo model – the assumption about delta-correlated in time random velocity field. This nonphysical assumption makes one unconfident in the correctness of the estimate of the dynamo threshold. In this work, using shell MHD models, we are trying to find out how accurate Kazantsev’s estimate of the generation threshold is, and how this threshold depends on the flow velocity, diffusion coefficients, and hydrodynamic helicity. This work was supported by the BASIS Foundation grant no. 21-1-3-63-1.
Regularized framework for inverse problems in continuous atmospheric emissions: An application to the Fukushima accident
Authors: Fang Sheng , Dong Xinwen , Zhuang Shuhan , Xu Yuhan
Published: March 2024

The inverse modeling technique has been widely adopted to estimate atmospheric emissions, which aims to complement the subjective inference and provides rare retrieval when unavailable source information. The inversion generally requires the environmental observations and the source-receptor relationship constructed by an air dispersion model. But these two kinds of input lead to an ill-posed inverse problem in continuous atmospheric emissions. For the observations, the measurement network cannot capture all information on a specific emission progress, because of the nature of spatial sparse and limited temporal collections. Besides, there are inevitable model-observation discrepancies introduced by the discretization and imperfect parameters in the physical model and the diagnostic meteorology model. In this dilemma, the estimated atmospheric emissions are featured with discontinuous elements such as temporal gaps, artificial oscillations, and negative values, which are biased from the continuous emission progress in the real world.This paper describes a regularized inversion framework to objectively address these artifacts and promote the continuity of emissions. This framework consists of the joint estimation model and the total variation (TV) regularization to handle the model-observation discrepancies and the insufficient observations respectively. The former implements site-by-site corrections by adding a diagonal matrix to the residual term of the inversion, and thus reduces the oscillations. The latter enhances a prior with the piecewise-constant feature by the L1-norm of the gradient of the emission vector, and therefore recovers the missing emissions. An adaptive parameterization scheme is tailored for the TV regularization to correct negative values.The proposed method has been applied to the Fukushima accident to estimate the lasting emissions of 137Cs, facing the observations with nearly half temporal incomplete of the estimation period and unavoidable deviations introduced by the atmospheric dispersion model. The results produce a discrete emission profile that accurately approximates the continuous emission progress, which better matches the recognized one by expert judgments than nine published estimates, with a Pearson’s correlation coefficient of 0.92 and an index of agreement of 0.82. The estimated profile agrees with the timing of on-site gamma dose rate peaks as well. The evaluation was also conducted with respect to atmospheric simulations, providing significantly improved air concentrations and depositions, with the ten-factor agreement (FAC10) values of 0.56 and 0.99 respectively. The uncertainty analysis with respect to the regularization parameters shows a limited variation range of the estimation error (median value below 15.04%), demonstrating the potential for operational inversions with automatic parameterization.
Paleoenvironment and Depositional Analysis of a Paleogene Formation: Terminal Fan Sedimentation Approach for Reservoir Quality Study in the Lower Shahejie Fourth Member, Bonan sag, China
Authors: Mioumnde Arthur Paterne , Zhang Liqiang , Yan Yiming
Published: March 2024

The lower fourth member of the Paleogene Shahejie Formation (Es4L) in Bonan sag, Bohai Bay Basin, East China was taken as an important target for oil and gas exploration in Shengli oilfield. Bonan sag is one of several sag in the Bohai Bay Basin, located in north-east China. Paleogene deposits are characterized by red rock layers, formed under a hot-warm and arid climate. Four depositional systems were developed in the Bonan sag. Among them, the fan delta developed in the central part of the study area, consisting of gray-white fine glutenite with poor sorting and rounding. The braided river delta is developed in the southern part with large lithofacies. The lithology shows some light gray conglomerate, pebbly sandstone, sandstone and small amount of mudstone. Floodplain facies is mainly developed in the inundated plain that in some weather conditions have the characteristics of shallow lake facies. However, a number of questions remain unanswered about the disparate presence of evaporites, the diverse colors of the mudstones and the varying levels of total organic carbon (TOC) in the area. These disparities can be seen in the many oscillations in TOC content, from the source of the sediments in the upper relief to the flood lacustrine plain. Consequently, given to this conditions, the depositional system which occurs in the area remains unclear from previous works. However, looking at the distribution of the sediments in an apparently short distance of less than 50km from the south to the North of sag, suggests that they are more likely to be terminal fan deposits. Terminal fans are an architectural system for draining and depositional process from high relief to flood plain, with gradual discharge of water through infiltration and evaporation. Although some researchers have conducted studies on terminal fans around the world, the concept remains unfamiliar and deserves to be more elucidated. This approach postulates to be useful to better understanding the sedimentary deposits in the Bonan sag and must be reviewed for similar hydrocarbon explorations elsewhere.
How to debrief geo-simulation/games: Some ideas and actions to make your debriefing more effective
Authors: Crookall David
Published: March 2024

Geogames have huge potential to enhance learning, but a crucial aspect often overlooked is the debriefing process. Debriefing, a reflective discussion during and/or following the game, allows players to consolidate their understanding of the concepts explored, reflect on their strategies and decisions, and identify areas for improvement. This reflective process plays a pivotal role in maximizing the learning outcomes of geogames, helping players acquire knowledge and develop critical thinking and problem-solving skills. Additionally, debriefing encourages a collaborative learning environment, where players can deepen relationships while they share insights and build a stronger understanding of geoscience concepts. By incorporating a structured debriefing session into the geogame experience, educators and researchers can significantly enhance the learning outcomes.  (Shortened and modified version of a paragraph generated by Bard.)That is the (rather bland) theory, but the practice is not easy, either to design or to facilitate.  My poster will present some of the practical aspects of debriefing.  We can also chat about the intricacies, about any challenges that you have faced or about ideas for debriefing your geogame or geosimulation.  We can also debrief a difficult debriefing that you experienced.  I will also give you the link to a downloadable 100-page chapter on the topic.
Geoethics literacy:  Clarifying values, principles and behaviour
Authors: Crookall David , Promduangsri Pimnutcha , Promduangsri Pariphat
Published: March 2024

Learning about geoethics is not easy partly because the area is relatively new (having emerged in the early 2010s), the concepts are sometimes difficult to fathom and geoethics touches on such a wide area of geoscience phenomena and on such a variety of human issues.Learning through active, participatory engagement has been developing since the 1960s, and is now deployed, albeit sporadically, across the full educational and training spectrum (from the humanities, through the social sciences to the hard sciences).  Methods that have developed in this learning paradigm include project work, internships, experiential learning, simulation/gaming, values clarification and many more.  We contend that participatory methods are an effective way in which to learn, as supported by much research.Our poster invites you to participate in a game-like, values clarification exercise.  We have developed a new version of an exercise that we have used in several places (Austria, Costa Rica, France, online) to unravel the knotty relations among values, principles and behaviours related to geoethical issues and dilemmas.It is possible to play alone, but it is more enlightening and engaging to play in pairs or small groups.  Please bring a friend or two to our poster and participate in our exercise.  The basic process of the exercise can be adapted to your own specific areas of interest.  We look forward to seeing you – please bring a pencil.(This poster was originally intended as a workshop in a short course, but our SC proposal was declined.)
Underestimated Arctic warming and potential ecosystem impact due to unresolved marine heatwaves
Authors: Gou Ruijian , Deng Yaocheng , Wolf Klara , Cui Yingzhe , Hoppe Clara , Wu Lixin , Shu Qi , Lohmann Gerrit
Published: March 2024

The Arctic is warming faster than any other regions, a phenomenon known as Arctic amplification, which has far-reaching effects for global climate. Modelled historical simulations show a significant underestimation of the amplification and the future projection exhibits non-negligible model spread. Here we show that in a future warming scenario, the warming in the Arctic is generally larger when comparing high-resolution climate models with low-resolution versions. We attribute the different extent of Arctic warming to Arctic marine heatwaves (MHWs), known as episodes of extreme ocean surface warming. The resolution of the MHWs, which are stronger and more realistic in the high-resolution model versions, increases the melting of sea ice and thus the absorption of solar radiation by the ocean in the short term, thereby reinforcing the long-term trend of Arctic warming. We point out that the amplification of Arctic warming is underestimated by the current generation of climate models, which generally have low resolution, thereby underestimating Arctic marine heat waves. In addition, Arctic heatwaves cause extreme temperature fluctuations associated with increased stratification. This poses major challenges to Arctic ecosystems and has a negative impact through direct physiological temperature effects and indirectly through nutrient supply and taxonomic shifts. We conclude that the eddy- and storm-resolving models provide a new perspective on how the Earth system responds to past and future climate and environmental extremes.