bluuebunny/crossref_metadata_2025 huggingface dataset:
Black carbon, organic carbon, and nitrogen oxide emission factors for traffic and domestic heating in an urban environment
Authors: Alfoldy Balint , Gregorič Asta , Ivančič Matič , Ježek-Brecelj Irena , Rigler Martin
Published: February 2023

Urban air quality deterioration has different reasons in warm and cold seasons. During summer, the photochemical production of secondary air pollution causes problems (ozone, secondary particles), while domestic heating significantly increases the primary emission during winter. In addition, the elevated emission is concentrated in a shallow mixing layer that leads to high air pollution levels. The source profile of domestic heating depends on the heating method. In European cities gas heating and wood combustion are the most common heating methods. Although distant heating is also commonly used, its emissions appear at the industrial source and are negligible for local air quality (similarly for less spread electric heating). In this work, we determined the emission ratios (ER) and emission factors (EF) of black carbon (BC), organic carbon (OC), and nitrogen oxide (NOX) in an urban environment, during the heating season. BC and OC concentrations were measured by the Carbonaceous Aerosol Specification System (CASS, Aerosol d.o.o, Slovenia), while NOX data was recorded by a nCLD-AL2 NOX analyzer (Eco Physics AG., Switzerland). The monitoring system was complemented by a Carbocap GMP-343 CO2 sensor (Vaisala, Finland) in order to measure the CO2 concentration for the EF calculation. The measurement took place in the atmospheric monitoring station of the Aerosol d.o.o in Ljubljana, Slovenia, which can be characterized as an urban background location. The source apportionment was implemented by using the Aethalometer model – multilinear regression combination (AM-MLR) assuming two major sources of urban air pollution: traffic and domestic heating. Fossil fuel-derived BC (BCFF) concentration was assumed as the tracer of traffic emission, while biomass burning-related BC (BCBB) was considered as the tracer of domestic heating. The Aethalometer model provides the source-specific (FF- or BB-derived) BC component. During the AM-MLR method, we supposed that the source-specific pollution component is correlated with the corresponding BC component (BCFF or BCBB). The slope of the regression line provides the ER, while the ratio of CO2 to the other pollutants can be converted to EF (g(kg fuel)-1) using the carbon balance approach. We applied the AM-MLR method to the dataset for the winter of 2021-2022 and determined the ER and EF values. The obtained EFs for traffic-related BC, OC, and NOX are 0.39, 0.33, and 0.03 g(kg fuel)-1 respectively, while the heating-related EFs are 0.13, 0.48, and0.01 g(kg fuel)-1 respectively. This work provided real-world emission factor data of a city that can help to estimate the total BC, OC, and NOX emissions in a city based on the sold fuel or consumed wood and gas.
Sub-surface characteristics of pop-up tectonics through field gravity and magnetic modelling: An example of the Shillong Plateau, NE India
Authors: Samantaray Suvankar , Pathak Priyank , Mohanty William Kumar , Gupta Saibal
Published: February 2023

The Shillong Plateau (SP) in NE India is one of the most debatable proterozoic basement in the world due to its complex tectonics. Though it had some collisional histories during the formation of the Gondwanaland associated with the Indo-Australo-Antarctic suture, but the signature of crustal and moho depth models gives a different idea about the modified crust under the SP. Despite its peak elevation at around 2000 m, the moho depth observed from the seismic tomography and satellite gravity data under the SP is not more than 34 km, which is remarkably smaller than the surrounding Bengal basin (⁓44 km) and the Brahmaputra basin (⁓44 km). We have tried to solve the problem related to the moho variation, taking into account the field gravity and magnetic anomaly. The major trends in the gravity anomaly predominant along EW direction conforming to the trends of regional geological structures across most of the SP. As our study area concentrates along an NS profile across two different litho units restricted to the central part of the plateau. The corrected field magnetic anomaly across the study area has a little variation between 0 to -500 nT, although some change in anomaly pattern can be seen along the northern side of the SP reaching towards -3500 nT. Moreover, the southern side of the plateau has very little magnetic anomaly variation. The bouguer gravity anomaly varies from ⁓ -70 mGal at the northern boundary to ⁓ +10 mGal with a steep gradient found across the southern side. The gradual change over to positive anomaly under SP, strong -ve anomaly under the Brahmaputra basin to the north and moderate negative anomaly under the Bengal basin towards the south suggested an uplifted moho under SP, which is demonstrated by the 2D gravity modelling. Closely spaced bouguer anomaly contours along the southern part and EW trending magnetic anomaly along the northern part of the SP, indicating two boundary faults viz. Oldham fault/ Brahmaputra valley fault in the North and Dauki fault in the south, dipping towards each other supported the SP for the formation of the pop-up tectonics.
Risk Assessment for climatic hazards: A case study of the Indian Sundarban Delta
Authors: Tuladhar Neshma
Published: February 2023

The Indian Sundarban Delta is facing adverse impacts of climate change and experiencing multiple climatic hazards like cyclones, floods, storm surges, and salinization. This directly impacts the life and livelihood of the delta dwellers. The hazard risks combined with anthropogenic risk drivers like high population density, poor economic conditions, and poor infrastructures have exacerbated their already challenging situation, prolonging their existing poverty loops and inequalities. The socio-economic profile is not consistent throughout the 19 administrative blocks of the Indian Sundarbans owing to the geographical variabilities, population composition, and resource availability and accessibility. These create a need for spatial comprehensive risk assessment to aid authorities in their planning and policies. Risk assessment was carried out for 19 blocks in Indian Sundarban based on the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) framework. The assessment has utilized several indicators under each component of the risk framework. The results depict that Patharpratima, Canning II, Haroa, and Basanti blocks are at high risk from climate change and associated disasters, followed by the blocks Hingalgunj, Minakhan, Canning I, Jaynagar I, and Namkhana. The risk assessment will help the respective authorities and government bodies to take necessary steps toward building a community resilient to natural disasters. The findings can be evidence for creating need-based and specialized adaptation and mitigation strategies in the blocks to deal with future climate-related variability and hazard events.
Contributions of External Forcing to the Decadal Decline of the South Asian High
Authors: Zhang Dapeng
Published: February 2023

The South Asian High (SAH) experienced a decadal weakening in the late 1970s under global warming. Based on an evaluation of the historical runs from CMIP6 models, we quantitatively assessed the contributions of different external forcing using “good” models that reasonably simulated the decadal decline of the SAH. All-forcing runs yielded the weakened SAH after the late 1970s, albeit the decadal decline was underestimated by most models. Compared to the insignificant contributions of greenhouse gas and natural forcing, anthropogenic aerosol played a dominant role in the decadal decline of the SAH. The increased aerosol likely drove a cooling surface over the Tibetan Plateau and East China via its effect on radiation. Consequently, the weakened heat source over the Tibetan Plateau and associated thermodynamic effects over East China would have driven a cooling of eddy temperature and cyclonic anomalies in the upper troposphere, respectively, thereby causing the decline of the SAH.
Complex seafloor spreading Knipovich Ridge and its crustal structure: insights from aeromagnetic data
Authors: Dumais Marie-Andrée , Gernigon Laurent , Olesen Odleiv , Johansen Ståle E. , Lim Anna
Published: February 2023

The interest for the polar regions and complex continental margins and ocean has increased during the last few decades. New technologies allow to conduct research in this hostile environment, permitting to investigate the tectonic and geodynamic history of the North Atlantic and Arctic oceans. In particular, the crustal and lithospheric structure of the Fram Strait and the transition from the Knipovich Ridge to the Barents Sea shelf and Svalbard are still poorly understood. Several multi-geophysical investigations from various campaigns since the 90s along the Western Barents Sea margin and the Northeast Greenland margin resulted in limited and contradicting interpretations of the crust and upper mantle. In this work, we study the spreading of the Knipovich Ridge and the regional tectonic of the Fram Strait and the Svalbard Margin.Our new KRAS-16 aeromagnetic data survey the complexity of the seafloor spreading history of the Fram Strait region. The high-resolution data identified the magnetic isochrons around the Knipovich Ridge and suggest the presence of several oceanic fracture zones and lineaments in the Fram Strait. The Knipovich ridge spreading initiated at C6 (20 Ma) and a ridge jump occurred at C5E. The oceanic crustal domain was consequently delineated. This new survey suggests that the continent-ocean boundary on the east Barents margin should be relocated up to 150 km farther west compared to previous studies. A 3-D magnetic inversion modelling identified zone with weak magnetization along the rift valley correlated with the absence of volcanic or bathymetric rise evidence. Combined with seismicity data available along the Knipovich Ridge, amagmatic and magmatic accretions show a segmentation of the seafloor spreading that correlates with the variation in magnetization along the rift valley. Furthermore, the new location of the continent-ocean boundary prompted to revise the existing 2-D seismic interpretations in terms of crustal interpretation and tectonic. This is tested further using joint 2-D gravity and magnetic field modelling and electromagnetic/magneto-telluric (CSEM/MT) data. A wide transition lithospheric domain likely comprising an exhumed lower crust or mantle is delineated from our interpretation. These results provide insights of the regional and structural nature of the Knipovich Ridge and its intricate development.
Population at Water Risk in World’s International River Basins
Authors: Varis Olli , Keskinen Marko
Published: February 2023

Slightly over half of the world’s human population lives in a river system shared by two or more countries. This transboundary aspect – caused by the utterly differing geographies of administrative country borders and river basins – adds to the intricacy of the global and continental-scale assessment of water-related risks. Whereas such assessments have started to evolve towards the inclusion of multiple hazards and stressors, vulnerabilities, exposures, and consequent risks, they have thus far been largely immune to the transboundary aspects of hydrology and water resources management. At the same time, the research on transboundary waters has its strongholds in matters such as risks related to conflicts or potential sources of conflicts, transboundary water agreements, and their diplomatic aspects, and other aspects related to water diplomacy, typically aiming at reducing political risks related to potential tensions and their mitigation between riparian countries. Bridges between these two strong research traditions are needed as international river systems are not immune to conventional water risks such as those related to hydrometeorology, contamination, or infrastructure deficiencies. We analyze spatially the exposure of the human population to ten major such water risks (due to interannual and seasonal variability; overuse; groundwater; coastal eutrophication; riverine and coastal floods; droughts, and water and sanitation services) in the major 310 international river systems of the planet. Our study approach (risk = stressor/hazard x exposure x vulnerability) aligns with that of the United Nations Sendai Framework and Intergovernmental Panel on Climate Change. Our results indicate that the lack of appropriate sanitation had globally the largest headcount, followed by riverine floods and lack of appropriate water supply. Each risk shows a specific pattern across the river systems, though. The largest human population at water risk was by far in the Ganges-Brahmaputra-Meghna system, followed by the Indus, Nile, Niger, Congo/Zaire, Rann of Kutsch, and Lake Chad Basin. Yet, many of these river systems have limited transboundary cooperation arrangements. The analysis outlines the importance of the transboundary aspect of water risks and their improved quantification in the pursuit of building up international cooperation and security through environmental management policies.
Deglacial- Holocene carbonate preservation in the Bay of Bengal
Authors: Narath Meethal Gayathri , Edayiliam Sreevidya , Subhakanta Bhoi , Subham Kesari Sahoo , Adukkam Veedu Sijinkumar
Published: February 2023

Deep-sea carbonate dissolution/preservation history is important to better understand marine carbonate system and surface ocean productivity. To understand carbonate dissolution during the last deglacial and Holocene periods in the Eastern BoB, we analyzed foraminifera carbonate dissolution indices viz., perfect test ratio (PTR) of Globorotalia menardii, Menardii fragmentation index (MFI), percentage of total resistant species (RSP), and percentage of total susceptible species (SSP). The core yielded rich assemblages of planktonic foraminifera though retrieved from deeper water depth (3019 m) of the Eastern Bay of Bengal. In general, the preservation is better during last glacial period on record (16-11.7 ka) and poor during Holocene. During Holocene, carbonate dissolution is intense in the early Holocene (12.5 to 8 ka), marked by increased MFI, and decreased PTR values along with less abundance of susceptible species. A slight decrease in the MFI was seen from 8 to 4.9 ka. The late Holocene period was characterized by less MFI and high PTR values. In general, MFI (PTR) was high (low) during the early Holocene compared to the deglacial and mid to late Holocene periods. Interestingly, the dissolution record shows a good relationship with Indian summer monsoon variability. The intense dissolution of the early Holocene might be due to changes in water column chemistry due to the increased river runoff and direct precipitation. We compared our data with existing records from the Andaman Sea and the Central Indian Ocean. The assemblages from the Bay of Bengal show a high degree of dissolution and low preservation during interglacial periods. The result of this study explains that dissolution is more pronounced during the warm interglacial and interstadials and MFI and PTR can be a potential proxy for quantitatively tracking deep marine CaCO3 dissolution in the Bay of Bengal. Keywords: Carbonate dissolution; Planktonic foraminifera, Globorotalia Menardii, deglacial, Holocene. 
A machine-actionable workflow for the publication of climate impact data of the ISIMIP project
Authors: Klar Jochen , Mengel Matthias
Published: February 2023

The Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) is a community-driven climate impact modeling initiative that aims to contribute to a quantitative and cross-sectoral synthesis of the various impacts of climate change, including associated uncertainties. ISIMIP is organized into simulation rounds for which a simulation protocol defines a set of common scenarios. Participating modeling groups run their simulations according to these scenarios and with a common set of climatic and socioeconomic input data. The model output data are collected by the ISIMIP team at the Potsdam Institute for Climate Impact Research (PIK) and made publicly available in the ISIMIP repository. Currently the ISIMIP Repository at data.isimip.org includes data from over 150 impact models spanning across 13 different sectors. It comprises of over 100 Tb of data.As the world's largest data archive of model-based climate impact data, ISIMIP output data is used by a very diverse audience inside and outside of academia, for all kind of research and analyses. Special care is taken to enable persistent identification, provenience, and citablity. A set of workflows and tools ensure the conformity of the model output data with the protocol and the transparent management of caveats and updates to already published data. Datasets are referenced using unique internal IDs and hash values are stored for each file in the database.In recent years, this process has been significantly improved by introducing a machine-readable protocol, which is version controlled on GitHub and can be accessed over the internet. A set of software tools for quality control and data publication accesses this protocol to enforce a consistent data quality and to extract metadata. Some of the tools can be used independently by the modelling groups even before submitting the data. After the data is published on the ISIMIP Repository, it can be accessed via web or using an API (e.g. for access from Jupyter notebooks) using the same controlled vocabularies from the protocol. In order to make the data citable, DOI for each output sector are registered with DataCite. For each DOI, a precise list of each contained dataset is maintained. If data for a sector is added or replaced, a new, updated DOI is created.While the specific implementation is highly optimized to the peculiarities of ISIMIP, the general ideas should be transferable to other projects. In our presentation, we will discuss the various tools and how they interact to create an integrated curation and publishing workflow.
The effect of 3DVAR data assimilation and convection-permitting scales on the simulation of precipitation and temperature over Western Europe
Authors: González-Rojí Santos J. , Raible Christoph C.
Published: February 2023

Data assimilation techniques can improve the simulation of regional precipitation and temperature over complex regions. Nowadays, regional climate simulations using convection-permitting scales are becoming available, but the number of those simulations including an additional data assimilation scheme is rather small because of their high computational costs. Hence, it is important to evaluate the effect of data assimilation schemes for such convection-permitting simulations, and to determine if data assimilation produces any improvement in the simulation of temperature or precipitation fields.To investigate this, we employ the Weather Research and Forecasting model (WRF; version 3.8.1) to dynamically downscale the state-of-the-art ERA5 reanalysis over Western Europe. A 3 km spatial resolution grid is employed, together with 51 vertical levels. The temporal resolution of the WRF outputs is one hour. Two model configurations are tested in two experiments spanning the period 2010-2020 after a one-year spin-up. In the first experiment (NoDA), after the initialization of the model, the boundary conditions drive the model. The second experiment (DA) is configured the same way as NoDA, but the additional 3DVAR data assimilation step (WRFDA) is run every six hours (00, 06, 12 and 18 UTC – analysis times). Observations obtained from the PREPBUFR dataset (NCEP ADP Global Upper Air and Surface Weather Observations) are employed, and only those included inside a 120 min window around analysis times were assimilated. For DA, monthly varying background error covariance matrices were created. In both cases, the model uses the Noah-MP land surface model, and high-resolution daily-varying SST fields from the NOAA OI SST v2 data set instead of the SST field from ERA5.The results of this study show that both experiments produce similar monthly precipitation patterns to those from observational data sets such as IMERG and CHIRPS, or the reanalysis ERA5. However, in general, and particularly during summer months, DA produces larger amounts of precipitation than NoDA. These amounts are in line with those from CHIRPS. In terms of temperature, DA show colder temperatures than NoDA in most of the months, which again are similar to those from observational data sets such as CRU or EOBS. The monthly temperature patterns of both experiments are similar to those from both observational data sets. These results highlight the fact that NoDA already is able to generate reliable precipitation and temperature fields compared to diverse gridded observational data sets, but the 3DVAR data assimilation can additionally improve the performance of the regional model when convection-permitting scales are employed.
Spatiotemporal land cover change trajectories across protected areas in Greece during the last decades
Authors: Gomaa Islam , Sultan Ghada , Markonis Yannis , Athanasiou Miltiadis , Pappas Christoforos
Published: February 2023

Ongoing environmental changes challenge climate-sensitive regions worldwide with Mediterranean ecosystems being also particularly affected. Satellite remote sensing techniques allow for quantitative insights into these patterns by capturing land cover characteristics across a wide range of spatiotemporal scales. Here, focusing on natural protected areas of the European network Natura2000, we quantify the trajectories of their land cover dynamics during the last decades. To do so, we explored satellite imagery from the publicly available Landsat archive, together with advanced cloud computing services, and land cover change detection algorithms. We analysed the spatiotemporal variability in land cover, as quantified with optical remote sensing (Normalized Difference Vegetation Index, NDVI), for more than 50 Natura2000 sites distributed across Greece. The selected sites cover a wide range of environmental conditions. land cover compositions and Mediterranean vegetation patterns (i.e., tall forests, evergreen shrublands, phryganic areas and/or grasslands). Three main land cover change trajectories are examined: (1) abrupt shifts, e.g., due to natural disturbances, such as wildfires, and gradual alterations, namely (2) increase, i.e., ‘greening’, triggered, for example, by more favorable environmental conditions, and (3) decrease, i.e., ‘browning’, following, for example, drought and heat stress. Across the examined sites, the NDVI showed substantial variability, reflecting different land cover characteristics and site-specific demographics and environmental conditions. Site-level long-term mean NDVI ranged from 0.3 to 0.8 with the overall temporal trends being weakly positive. When these lumped spatiotemporal dynamics were disentangled, sites heavily affected by wildfires were identified (showing >50 % losses of their total vegetation cover) as well as sites with chronic decrease or increase in vegetation cover. Given the high significance and numerous services provided by such protected areas, a comprehensive quantification of their land cover dynamics not only enhances our process understanding, but also offers valuable insights to policy makers for the development of mitigation strategies.
Improving crop dynamics in the CLM5 land surface model
Authors: Reddy K Narender , Baidya Roy Somnath , Bhattacharya Bimal K , Varma G Venkateswara
Published: February 2023

The land surface is an essential component of the Earth's System that interacts with the atmosphere via mass, momentum, and energy exchange. Croplands are one of the most common types of land use. Therefore, a comprehensive understanding of land-atmosphere interactions requires understanding the biogeochemical and biogeophysical processes and interactions in agroecosystems.Earth System Models (ESMs) can simulate the complex physical, chemical, and biological processes within and between the earth's land, atmosphere, ocean, and other spheres. Croplands have not received adequate attention in ESMs and were previously represented as grasslands. Land components in ESMs, such as the Community Land Model version 5 (CLM5) in the Community Earth System Model (CESM), have recently begun to include specific crops. The addition of crops to land models improved the simulation of energy, carbon, and water fluxes from land. CLM5 can represent a wide range of crops all over the world. However, there are significant errors in crop representation for the Indian region, including cropping areas, cropping season, irrigation, and crop characteristics. CLM5's estimated annual yield of wheat and rice has significant biases compared to UN-FAO estimates due to differences in growing seasons. Furthermore, observational data on the phenology of spring wheat and rice are scarce in the Indian region. As a result, crop growth model simulations in the Indian region suffer from poor calibration and validation.India is the world's second-largest producer of wheat and rice. Rice and wheat croplands cover more than 70 million ha combined. The current study aims to improve CLM5's representation of spring wheat and rice crops. This is accomplished by incorporating a crop planting window based on observations, wheat and rice cultivated area and irrigated cropland maps from district-level data. To further improve the crop models, we digitized historical crop phenology data and used them for model calibration and validation.Correcting the spring wheat and rice growing seasons in CLM5 over India has greatly improved crop phenology, yield, and irrigation pattern. As a result, the energy, carbon, and water fluxes are better estimated than the default CLM5 model. If the improved CLM5 is incorporated into the CESM, this can also improve the simulation of atmospheric phenomena. 
EPOS Open Source: A platform for integrating high-quality research products and services.
Authors: Vinciarelli Valerio , Orfino Andrea , Paciello Rossana , Bailo Daniele , Goffi Claudio , Giuliacci Kety , Sbarra Manuela , Michalek Jan , Nedrebø Harald , Roquencourt Jean-Baptiste , Retout Yann , Warren Daniel , Lavrnja-Czapski Janusz
Published: February 2023

The European Plate Observing System (EPOS) is releasing a pan-European research infrastructure (RI) for Solid-Earth sciences that targets different scientific communities. The EPOS RI enables sharing of data and resources; promoting collaboration, harmonization of practices and methods, fosters innovation and novel scientific discoveries. These principles of scientific and technological collaboration are the basis of the concepts of Open Source and Open Collaboration.EPOS consists of essentially two components: firstly, the so-called Thematic Core Services (TCS) representing the Data providers from the scientific domains (e.g., Seismology, Satellite data etc.); secondly, the central integration node, namely the ICS-C (Integrated Core Services – Central Hub), representing the integrating ICT (Information and Communication Technology) system underpinning the EPOS Data Portal.EPOS is currently releasing the Open-Source version of its architecture, based on microservices, which includes a GUI (Graphical User Interface) implementing the Data Portal, i.e., the human oriented interface for accessing the assets made available by the TCS. It communicates with the ICS-C system by means of RESTful APIs which also implement AAAI (authentication, authorization, accounting infrastructure). Through the APIs, the Data Portal queries the metadata catalog to discover and contextualize assets of interest provided by the TCS and documented as metadata.In order to integrate heterogeneous datasets from the TCS, appropriate metadata and semantic descriptions are used to drive interactions with TCS resources or to construct a workflow to be executed across TCS.EPOS Open Source also includes a microservice to enable the interaction with large-scale computing resources or geoscience software services, represented in EPOS as ICS-D (Integrated Core Services – Distributed). The different processing done through the ICS-D on the TCS data are also metadata driven, the software executed on the ICS-D, which enable additional features and functionalities to the ICS-C core, have their own metadata description and through a plugin architecture run on the ICS-D.The architecture is designed to integrate with e-Infrastructures such as GRID or CLOUD facilities and particularly ongoing work includes achieving interoperability with EOSC (European Open Science Cloud) by means of FAIR web services. The EPOS architecture has also been used as a template in other initiatives such as other Environmental Science RIs (e.g., ENVRI Catalogue of Services) and Jerico.In the presentation we will describe the work done so far and the key concept that brought to the adoption of a microservice based, open-source released architecture, and provide perspectives for future extension of the project.
MgO nanocube hydroxylation and carbonation by nanometric water films
Authors: Boily Jean-François , Luong N. Tan , Holmboe Michael
Published: February 2023

Hydrophilic nanominerals exposed to air moisture host thin water films that are key drivers of reactions of interest in terrestrial and atmospheric settings. Water films can trigger irreversible mineralogical transformations, and control chemical fluxes across networks of aggregated nanomaterials. Using X-ray diffraction, vibrational spectroscopy, electron microscopy, and (micro)gravimetry we tracked water film-driven transformations of periclase (MgO) nanocubes to brucite (Mg(OH)2), as well as to amorphous magnesium carbonate (AMC) in the presence of moist CO2. We show that 3-4 monolayer-thick water films first triggered the nucleation-limited growth of brucite and AMC, and that water film populations continuously grew on newly-formed nanoparticles. Small (8 nm-wide) nanocubes were completely converted to brucite under this growth regime, while growth on larger (32 nm-wide) nanocubes transitioned to a diffusion-limited regime when (~1.3 nm-thick) brucite nanocoatings began hampering the flux of reactive species to growth fronts. In contrast, AMC growth was limited to the nucleation-limited regime as nanocoatings hindered the transport of reactive species from the MgO core to growth fronts. By resolving nanocoating growth on a model reactive hydrophilic mineral, this work provides new insight into the study of water film-driven nanomineral transformations that are important to geosciences.
Nonlinear processes in tsunami simulations for the Peruvian coast with a focus on Lima/Callao
Authors: Androsov Alexey , Harig Sven , Zamora Natalia
Published: February 2023

Numerical simulations of the tsunami inundation processes require a highly nonlinear scheme. The main inundation properties, such as theflow depth and velocity depend critically on topographical imprints and bottom friction parameters. Here, we investigate the tsunami inundation in Lima and Callao resulting from the extensive 1746 (Mw 9.0) earthquake that ruptured along the Peruvian coast.Two numerical tsunami codes have been used in this analysis based on shallow water equations. We determine the relative importance of different parts in these equations with a focus on nonlinear terms. Particular focus is put on the momentum advection, bottom friction, and volume conservation in different mesh (triangular meshes and nested grids). We determine the influence on large-scale quantities like inundation extent and volume, flow velocities, and small-scale fluctuations. In that respect, also sensitivities regarding the bottom friction parameters are investigated.
Accelerating the understanding of plant response to drought stress
Authors: Alidoost Fakhereh , Liu Yang , Schilperoort Bart , Su Zhongbo , Zeng Yijian
Published: February 2023

Climate extremes like droughts and heatwaves impact how water, energy, and carbon move through ecosystems. Soil-water-plant-energy interactions can be represented by SCOPE (vegetation photosynthesis model) and STEMMUS (soil water and heat model). SCOPE simulates the radiative transfer of incident light and thermal and fluorescence radiation emitted by soil and plants, temperatures of leaves and soil in the sun and shade, photosynthesis and turbulent heat exchange whereas STEMMUS traces soil moisture and soil heat dynamics and root water uptake.  The integrated model, “STEMMUS-SCOPE”, thus links vegetation dynamics to soil moisture and soil temperature variability. This helps to simulate evaporation, transpiration and carbon fluxes better, especially under water stress conditions. With STEMMUS-SCOPE, we can model variables like moisture levels in deeper soil (root-zone-soil moisture) and the amount of carbon that is stored underground (carbon sequestration) at a global scale.  However, applying STEMMUS-SCOPE across ecosystems at a global scale faces numerical problems and computational challenges, such as numerical convergency of the model, optimization issues in calibration, and expensive computational cost. To overcome the challenges, we are developing tools for efficient computing and data handling within the context of EcoExtreML project. The project aims to improve the coupling of STEMMUS and SCOPE models, approximate the integrated model by a machine learning approach, and estimate uncertain model states and parameters using data assimilation techniques. The results of STEMMUS-SCOPE are currently prepared for 170 flux tower sites representing 1040 site-years of data with a half-hour time step across most of the world’s climate zones and representative biomes. In this talk, we will give you an overview of STEMMUS-SCOPE, show how the model can be used, and introduce EcoExtreML project. References:  SCOPE: https://doi.org/10.5194/bg-6-3109-2009,  https://github.com/Christiaanvandertol/SCOPE STEMMUS: https://doi.org/10.1007/978-3-642-34073-4, https://github.com/yijianzeng/STEMMUS STEMMUS–SCOPE : Integrated modeling of canopy photosynthesis, fluorescence, and the transfer of energy, mass, and momentum in the soil–plant–atmosphere continuum (STEMMUS–SCOPE v1.0.0), https://doi.org/10.5194/gmd-14-1379-2021  EcoExtreML project: Accelerating process understanding for ecosystem functioning under extreme climates with Physics-aware machine learning, https://research-software-directory.org/projects/ecoextreml, https://github.com/EcoExtreML  
Energy and fertiliser price rises are more damaging than food export curtailment from Ukraine and Russia for food prices, health and the environment
Authors: Alexander Peter , Arneth Almut , Henry Roslyn , Maire Juliette , Rabin Sam , Rounsevell Mark
Published: February 2023

Higher food prices arising from restrictions on exports from Russia or Ukraine have been exacerbated by energy price rises, leading to higher costs for agricultural inputs such as fertiliser. Using a scenario approach with a global land use and food system model (LandSyMM), we quantify the potential outcomes of increasing agricultural input costs and the curtailment of exports from Russia and Ukraine on human health and the environment.  We show that, combined, agricultural inputs costs and food export restrictions could increase food costs by 60-100% from 2021 levels, potentially leading to undernourishment of 60-110 million people and annual additional deaths of 400 thousand to 1 million people if the associated dietary patterns are maintained. In additional to lower yields, reduced land use intensification arising from higher input costs would lead to agricultural land expansion of 130-349 Mha by 2030, with associated carbon and biodiversity loss. The impact of agricultural input costs on food prices is larger than that from curtailment of Russian and Ukrainian exports. Restoring food trade from Ukraine and Russia alone is therefore insufficient to avoid food insecurity problem from higher energy and fertiliser prices. While the Black Sea Grain Initiative has been a welcome development and has largely allowed Ukraine food exports to be re-established, the immediacy of these issues appears to have diverted attention away from the impacts of fertiliser prices. While fertiliser prices at the start of 2023 have come down from the peaks of mid-2022, they remain at historically high levels.  Our results suggest the costs and lower crop yields achieved through reduced fertiliser use will drive high food price inflation in 2023 and beyond. More needs to be done to break the link between higher food prices and harm to human health and the environment.  This study demonstrates how modelling can be used to explore the complexity and interlinked nature of the globalised food system and to quantifying the trade-offs and synergies for health and environmental outcomes of difference scenarios.
Ionospheric mid-latitude electron density background definition from CHAMP and Swarm satellite measurements under different solar conditions
Authors: Sabbagh Dario , Ippolito Alessandro , Marchetti Dedalo , Perrone Loredana , De Santis Angelo , Campuzano Saioa A. , Cianchini Gianfranco , Piscini Alessandro
Published: February 2023

In this work, a new method to define a background for the topside ionospheric electron density from satellite in-situ measurements is proposed as a useful tool for analysis of plasma density variations at LEO satellites heights. The method is applied to the data acquired by the Langmuir Probes onboard CHAMP satellite during the years 2004 and 2009, and the three Swarm satellites during 2016 and 2017 in the 15°-wide mid-latitudinal belt from 35°N to 50°N, and any longitude. CHAMP/Swarm in-situ measurements have also been used to check and compare such a new defined background with the one computed directly from IRI-2016 electron density output at satellite altitude. A general overestimation of the electron density from IRI during noon hours is highlighted, despite an underestimation of IRI with respect to Swarm-derived background for Swarm 2017 data is found as well, while the two backgrounds result more in agreement during night-time. Finally, the analysis of 2004 plasma data suggests that the IRI-2016 model could be used as a background during periods characterized by high levels of geomagnetic activity under high solar activity conditions.
Experimental reactivation of faults in marble across the brittle ductile transition
Authors: Rybacki Erik , Niu Lu , Zhou Youngsheng , Xu Xiwei
Published: February 2023

The reactivation and stability of faults depend on a number of parameters, like rock composition, (effective) normal pressure, fault roughness, and loading rate. However, not much in known about the impact of temperature on faulting behavior. Using a Paterson-type gas deformation apparatus, triaxial compression experiments were conducted on dry Carrara marble samples containing a saw-cut oriented at about 40° to the axial stress direction. The tests were performed at constant axial strain rate of 1x10-5 s-1, confining pressures, P, between 30 and 150 MPa, and temperatures, T, in the range of 20 to 600°C. Under these conditions, intact Carrara marble deforms mainly in the semi-brittle regime and brittle, localized, deformation associated with strain weakening occurs only at room temperature and P < 100 MPa. At similar temperature, saw cut samples show formation of a new fracture zone inclined at 30° to the loading direction at P = 30 MPa and fault reactivation with stable sliding on the preexisting fault at P = 50 MPa. At higher temperatures up to 400°C and pressures < 100 MPa, we observed a mixture of matrix deformation and unstable (stick-slip) sliding on the fault. The peak stress at the onset of fault reactivation increased with P and T, resulting in higher associated peak strain. Also, the peak stress drop increased with increasing peak stress. At high T (>400°C) and P (>100 MPa) the fault remained locked and samples revealed ductile matrix creep with strain hardening, where the strength is almost similar to the strength of intact sample deformed under similar conditions. Microstructural observations reveal intense microcracking at the lowest P-T conditions. Samples exhibiting stick-slip behavior show a thin, discontinuous gouge layer and high twin density in specimens with late (high stress) fault reactivation. Bulk creeping samples reveal less damage and the fault appears to be partially sealed. Electron backscatter diffraction measurements suggest a slightly increasing crystallographic preferred orientation in the direct neighborhood to the fault compared the matrix under most conditions. Our results indicate that the fault reactivation stress of marbles increases with both, pressure and temperature, limited by the frictional strength. Above the brittle-ductile transition, the strength is limited by the bulk flow strength, which depends on total strain due to strain hardening, eventually leading to failure at high strain.
Differences between subtidal and intertidal benthic biogeochemistry: implications of intertidal area loss for ecosystem functionality
Authors: Rios Yunes Dunia , Tiano Justin C. , De Borger Emil , van Oevelen Dick , Soetaert Karline
Published: February 2023

Coastal areas are subjected to several anthropogenic stressors with much of the world’s intertidal areas receding due to human activities, coastal erosion, and sea level rise. The Eastern Scheldt (ES) tidal bay in The Netherlands is predicted to lose around 35 % of intertidal areas by 2060. Our study investigated differences between biogeochemical fluxes of intertidal and subtidal sediments of the ES and assessed how ongoing intertidal loss may modify the sedimentary ecosystem functioning of this tidal bay in the coming decades. Monthly fluxes and porewater concentrations of dissolved inorganic nitrogen (DIN), phosphorous (DIP), silica, carbon and oxygen (O2) as well as organic matter characteristics were measured from intertidal and subtidal sediments from June 2016 – December 2017. O2 fluxes were 37% higher in the intertidal, and these sediments exhibited influxes of nitrates (-1.2 mmol m-2 d-1) and DIP (-0.03 mmol m-2 d-1). In contrast, subtidal sediments exhibited an average efflux of nitrates (0.28 mmol m-2 d-1) and DIP (0.09 mmol m-2 d-1). Intertidal areas removal of DIN and DIP was 34 % and 38% higher than in the subtidal suggesting stronger denitrification and phosphorus adsorption to solid particles. The potential loss of biogeochemical functionality due to intertidal area loss by 2060 was estimated. In the next 40 years, the ES tidal bay may experience a reduction of 11 % and 8 % for respective nitrogen and phosphorus removal. Given the global observations of eroding intertidal areas and rising sea levels, we suggest that the predicted habitat loss may cause significant changes for coastal biogeochemistry and should be investigated further to understand its potential consequences for coastal ecosystems.
Large ensemble particle filter for proxy-based spatial reconstructions of the last 2000-years climate variability
Authors: Jebri Beyrem , Khodri Myriam
Published: February 2023

Proxy records (corals, marine sediments, etc.) documenting the last 2000 years (2K) provide evidences for the wide range of natural variability not captured by recent direct observations. Assessing climate models ability to reproduce such natural variations is crucial to understand climate sensitivity and impacts of future climate change. The length of record is relatively short for investigating slow climate features, especially when considering coupled ocean-atmosphere variability. In order to extend the information contained in proxies from the locations and times to which they pertain, additional information is needed to create a climate field reconstruction. Paleoclimate data assimilation offers a powerful way to extend the instrumental period and better characterize the decadal to secular natural ocean variability by optimally combining the physics described by climate models with information from available observations while taking into account their uncertainties. Here we present a new Proxy Data Assimilation product based on a sequential importance resampling particle filter (PF-SIR) that uses Linear Inverse Modeling as an emulator of GCMs, providing dynamical ocean memory and improving the reconstruction of low-frequency climate variability. The climate reconstructions include robust uncertainty quantification and a set of physically consistent spatial fields useful for dynamical inquiry beyond what is feasible from proxies or climate models alone. We use these new results to explore low-frequency aspects of main coupled variability modes and provide some constrains on climate model simulations for the last millennium.
Drought-to-flood transitions – When and where do they occur?
Authors: Götte Jonas , Brunner Manuela
Published: February 2023

Drought-to-flood transitions are both a challenge and opportunity for water management. While the two extremes are often studied separately, their close succession can have severe impacts. The timespan between events can range from rapid transitions happening within a few days to long transitions taking many years. Still, the drivers and frequency of those transitions in specific river basins remain unknown. Therefore, we ask ‘when, where and how often do transitions from streamflow droughts to floods occur?’To answer these questions, we analyse over 1000 catchments in the contiguous US from the GAGES-II database, identify streamflow droughts and floods, and calculate transition times between both types of extremes. Then, we relate the time and frequency of occurrence and the timespan between extremes to local climate and topographic characteristics. We distinguish between winter and summer transitions to identify hydro-meteorological processes important in different seasons and focus on particularly rapid transitions. We find that the duration and frequency of transitions show large spatial variability. Regionally, rapid transitions occur during a typical time of the year which is often related to the presence of snow and melt processes. Snow also dictates seasonal differences in rapid transition frequencies between summer and winter. Snow-free catchments have a lower frequency but higher variability of transitions which makes the phenomenon less predictable. Additionally, reservoirs reduce the occurrence of snow-affected rapid transitions. We conclude that management challenges related to drought-to-flood transitions are particularly pronounced in natural and rainfall-dominated catchments.