bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil Organic Carbon Estimation in Croplands by Integrating Soil Spectral Library and PRISMA Data
Authors: Bonthu Sandeep Reddy , Hassan Rangaswamy Shwetha
Published: February 2023

Soil organic carbon (SOC) is a crucial component of soil and is used as a proxy for soil health and fertility. SOC influences water and nutrient holding capacity, nutrient cycling and stability, and water infiltration and aeration properties of soil. Proximal Sensing and Remote sensing are two powerful tools well covered in literature used for quantitative analysis of SOC. It is difficult to examine the nutrients of the soil due to insufficient time for collecting soil samples from agricultural fields during the crop rotation process in countries like INDIA, where extensive agriculture is practiced. In this scenario, linking soil spectral libraries (SSL) developed from proximal sensing with RS image data would enable instantaneous estimation of SOC over a large command area.A model (calibration using multivariate techniques) which contains the variability of the target site soils should be constructed in this process to extract useful information. However, many times this criterion is not easy to fulfil. To solve this problem, we propose building a soil spectral library using soil samples synthesised in lab conditions and further constructed SSL to estimate SOC and essential soil nutrients. In this regard, spectrum data of collected Alluvial soil samples were generated in lab conditions using ASD FieldSpec 4, while simultaneously analysing soil samples based on standard methods in soil science. A soil sample collected from the field was selected as the master sample, and sub-samples were prepared by combining soil with organic fertiliser and chemicals (spatial structure similar to soil compounds) of various compositions. The emissivity spectra of soil sub-samples were used to construct a spectral library and later used in the machine learning model to estimate the spatial variation of SOC utilizing space-based hyperspectral image (PRISMA). The results revealed that the proposed model for SOC estimation using spectral library is significant for the instant estimation of SOC. Future scope includes testing the approaches' capability for estimating essential soil nutrients in various soil origins.
Wetlands are the primary hotspots of carbon accumulation in proglacial areas
Authors: Janssen Noortje , van Grinsven Sigrid , Temme Arnaud
Published: February 2023

Glacial retreat is a well-known effect of global warming. Where glaciers retreat, land becomes available for soil formation. The water that is produced by the melting of the glaciers forms a stream system in the newly available land, and together these form the proglacial area, or glacial forefield. Proglacial areas are interesting study areas for a negative feedback loop of global warming: where land becomes available, microbial and plant biomass are formed, taking up CO2 from the atmosphere. For inland glaciers, dry soils generally cover most of the surface of proglacial areas, with only a very small fraction covered by wetlands.Using detailed carbon stock data, CO2 flux measurements, and GIS methods, we assessed the contribution of soils and wetlands to the valley-wide carbon storage in a proglacial valley in the Martellertal, Parco Nazionale dello Stelvio, Italy. We explored the relationship among the CO2 flux, soil carbon content, and location factors such as slope steepness, rock and vegetation cover, and litter layer thickness. Furthermore, we studied the relationship between the soil age, or time since deglaciation, and carbon stocks and fluxes. Our data shows that wetlands are major carbon storage hotspots: not only was the carbon stock significantly higher at wetland sampling locations, also the CO2 uptake per surface area was significantly higher than in dry soils. These findings suggest that despite their small spatial coverage, wetlands are key areas to consider when assessing proglacial carbon budgets, both from a carbon storage as well as a carbon flux viewpoint.
Evidence of Strain Localization Preceding Rock Failure: Insights From Laboratory and Physics-Based Poroelastic Models
Authors: Bianchi Patrick , Selvadurai Paul Antony , Salazar Vásquez Antonio , Dal Zilio Luca , Madonna Claudio , Gerya Taras , Wiemer Stefan
Published: February 2023

At present, a reliable method for forecasting earthquakes has not been developed yet, as the physical mechanisms that generate them are very complex and still not completely understood. To overcome the difficulties of retrieving direct observations and measurements in the field, here we employ laboratory and numerical models to investigate and better understand strain localization preceding mainshocks.We perform a failure test on an intact and dry sample of Berea sandstone confined at 20 MPa with a triaxial machine (LabQuake). Employing in-house developed, conical-type and fully calibrated piezo-electric transducers (PZT), we are able to investigate the acoustic emission (AE) clouds by relocating the single events and by computing their focal mechanisms and scalar seismic moments. The PZT sensors are also used actively to allow for the construction of inhomogeneous and anisotropic velocity models. We further employ distributed strain sensing (DSS) with optical fibers to capture the heterogeneous spatial distribution of the surface strain by gluing the fibers on the sample surface. We observe AE clustering in two regions located at the top and bottom of the rock specimen throughout the majority of the experiment. As the test approaches the main failure, AE localize at one side of the sample in the lower half before obliquely propagating upwards by forming a macro-fracture. Surface strain heterogeneities are detected during the experiment, and regions of higher extensional strain correlate in time and space with rock volumes experiencing high AE activity. Numerical simulations, which are conducted using a two-dimensional continuum-based and fully coupled seismo-hydro-mechanical poro-visco-elasto-plastic modelling tool (H-MEC), are validated with both AE and DSS data. The combination of laboratory and numerical investigations allows us to individuate and study physical mechanisms (e.g., visco-plastic compaction of pores and shear banding) that explain the processes responsible for both surface strain concentration and the generated AE clouds. These findings suggest that the deformation in the interior of the sample is mainly occurring inelastically and is localized along an obliquely forming shear band. We estimate the partitioning between seismic and total deformation to be ~0.09 % and this effectively confirms the previous evidences related to the irreversible localization of strain within the rock specimen. 
Role of Geological Surveys of Europe in landslide monitoring
Authors: Jemec Auflič Mateja , Herrera Gerardo , Mateos Rosa María , Poyiadji Eleftheria , Quental Lídia , Severine Bernardie , Peternel Tina , Podolszki Laszlo , Calcaterra Stefano , Kociu Arben , Warmuz Bartłomiej , Jelének Jan , Hadjicharalambous Kleopas , Peterson Becher Gustaf , Dashwood Claire , Ondrus Peter , Minkevičius Vytautas , Todorović Saša , Møller Jens Jørgen , Marturia Jordi
Published: February 2023

This work was developed by the Earth Observation and Geohazards Expert Group from EGS and provides an overview of landslide monitoring techniques from 2005 to 2021. Based on the questionnaire, the following objectives were set: (1) to identify the type of monitored landslides, (2) to identify the landslide monitoring techniques, (3) to identify the spatial resolution, temporal resolution, and status of the technique (operational, non-operational), time of using (before the event, during the event, after the event), and applicability of the technique to the early warning system. The main contribution of this paper is to show the involvement of EGS in landslide monitoring and discuss the importance of geological data, which is often underestimated because of the use of relatively traditional, time-consuming methods. The collaborative work of 17 Geological Survey members of the Earth Observation and Geohazards Expert Group (EOEG) provided the landslide monitoring information and made this review possible. This review builds on landslide monitoring techniques at Geological Surveys, not only providing the review of the most often used techniques but also serving to highlight the importance of geological data in landslide monitoring. In addition, it provides new insights into the role of Geological Surveys in landslide monitoring.Reference: Jemec Auflič, M., Herrera, G., Mateos, R.M. et al. Landslide monitoring techniques in the Geological Surveys of Europe. Landslides (2023). https://doi.org/10.1007/s10346-022-02007-
Structural setting for a geothermal system at the eastern boundary of the Roer Valley Rift System – A case study from the Viersen Fault Zone in the vicinity of Straelen, Germany
Authors: Jüstel Alexander , Rubach Philipp , Balza Morales Andrea , Kettermann Michael , Ritzmann Oliver , Wellmann Florian
Published: February 2023

Geothermal systems have been developed in Paleozoic rocks within the Roer Valley Rift System (RVRS) on the Campine Block in Belgium in the West (e.g. Mol) and the Peel Block in the Netherlands in the East (Tegelen Fault, Californië project). However, no geothermal system has been developed further along the eastern boundary of the RVRS where the tectonically active Viersen Fault Zone (VFZ) is located. This fault zone separates the elevated Krefeld Block from the Venlo Block located near Straelen, Germany. Given the high demand for heat by local greenhouses, the city of Straelen and its surroundings would greatly benefit from geothermal developments. In this study, we aim at characterizing the subsurface structures of the VFZ to estimate the geothermal potential of the Dinantian carbonates, Upper Devonian Condroz sandstones and deeper targets like the Upper/Middle Devonian limestones. This is done by reinterpreting seismic data acquired within the framework of the Californië project, analyzing recently acquired data within the framework of the SCAN project and new gravity measurements performed in the Straelen area. The seismic interpretation indicates fault linkages and relay structures which can be correlated to surface expressions and the recorded gravity measurements. The potential geothermal reservoirs were mapped and horizons were interpolated between the seismic lines with insights provided from gravity results. Our investigations illustrate the previously undescribed segmentation of the Viersen Fault Zone in the Straelen area. This tectonic deformation may promote or enhance fluid flow within the reservoirs in the vicinity of the VFZ similar to the geothermal system developed along the Tegelen Fault in the Netherlands. However, the current permeability of these damage zones in VFZ within the reservoirs requires further local subsurface investigations and in-situ tests through drillings to characterize the hydraulic properties and to map the reservoirs and associated structures in 3D. 
Modelling discontinuities in ice flow using the Material Point Method and elastoplasticity
Authors: Rousseau Hugo , Gaume Johan , Blatny Lars , Lüthi Martin P.
Published: February 2023

Understanding glaciers evolution is of major concern to evaluate their contribution to sea level rise in the context of global warming. Among the various processes involved in glacier dynamics, fractures like the calving of ice at the front of marine terminating glacier and crevasse formation affect the stress state, potentially modifying the glacier’s velocity. Crevasses also impact the melting rate. The fractures alter the roughness of the ground, increasing the amount of absorbed radiation, and open new networks in which the meltwater is likely to penetrate deeper toward the glacier bed.In this work we propose to model fractures in glacier based on finite strain elastoplasticity, using the Material Point Method (Wolper et al. 2021): we solve the classical governing equations for ice deformation in an Eulerian-Lagrangian framework and we use a strain softening Drucker-Prager constitutive model to simulate plasticity. Thanks to the Lagrangian part of the model, the fractures appear explicitly where high levels of total plastic deformation are reached. The behaviour of a glacier flowing over a step in the bedrock is investigated. The simulations show that crevasse patterns appear with regular spacing between the fractures. We perform a parametric study to determine which parameters affect the length of these patterns and potential dimensionless numbers are outlined.
Simulation of submarine landslides and generated tsunamis in Mayotte : comparison of different models
Authors: Poulain Pablo , Le Friant Anne , Mangeney Anne , Pedreros Rodrigo , Grandjean Gilles , Lemoine Anne , Fernandez-Nieto Enrique , Castro-Diaz Manuel , Peruzzetto Marc
Published: February 2023

Since May 2018, Mayotte island has experienced an important seismic activity linked to the on-going sismo-volcanic crisis. Although variations in the number of earthquakes and in their distribution have been observed since the start of the eruption in early July 2018, a continuous seismicity persists. It could weaken the steep submarine slopes of Mayotte, as highlighted by the high-resolution bathymetry data collected during the MAYOBS cruise in May 2019. This could trigger submarine landslides with associated tsunamis.To address the hazards associated with such events, we analyzed geomorphological data to define 8 scenarios of potential submarine landslides with volumes ranging from 11,25.106 to 800.106 m3. We simulated the resulting landslide dynamics as well as generated waves (Poulain et al. 2022). In order to estimate the uncertainty associated to the modeling approach, a hierarchy of different model approximations was tested, spanning hydrostatic, non-hydrostatic and multilayer approaches. A sensitivity analysis was also performed by varying the initial released mass, the rheological parameters describing the landslide, its interaction with the water column, the Manning friction coefficient as well as the resolution of the bathymetry description. The combination of all these elements provides an estimate of the uncertainty on simulation results. We show that, in the context of Mayotte, non-hydrostatic effects have the most prominent influence on simulated water elevation and waves velocity. Other key factors include the friction coefficient within the landslide and the resolution of the bathymetry. These results show that landslide-tsunami models should still be improved as well as the estimates of the parameters involved to reduce the related uncertainties on the water wave calculation (water elevation, velocity) that can exceed a factor two.Poulain, P., et al. (2022). Numerical simulation of submarine landslides and generated tsunamis: application to the on-going Mayotte seismo-volcanic crisis. Comptes Rendus. Géoscience, 354(S2), 1-30. 
Towards the modelling of debris flow-forest interaction: MPM-DEM
Authors: Liang Zhengyu , Choi Clarence Edward
Published: February 2023

Forests cover almost 40% of low-elevation mountains globally. Forests are sometimes considered a nature-based solution against granular flows. Owing to the complexity of the dynamics of granular flows, the protective effects of forests cannot be easily implemented into existing hazard mitigation strategies and frameworks. In this study, the interactions between dry granular flows and idealised model forests are simulated using a MPM-DEM solver.  To produce high-fidelity evidence of flow–forest interactions, a new experimental model forest was developed. The effects of forest pattern and tree spacing were investigated. The experimental evidence was used to validate and calibrate the said MPM-DEM solver. Findings reveal that interactions between overlapping bow shocks at the tree-scale considerably affect the mobility of a dry granular flow moving through a forest. Bow shocks serve to either reduce flow momentum or concentrate momentum, which can boost the runout distance by up to 1.5 times compared with the runout distance on bare terrain without trees. The effects of bow shocks on flow momentum can be used as a guiding tool to assess the design of cultivated forests in impeding dry granular flows.
Preliminary results from U-Pb dating and geochemical characterization of GRIND-ECT carbonate samples from Namibia
Authors: Cantine Marjorie , Gerdes Axel , Eitel Sören , Ovtcharova Maria , Müller Inigo
Published: February 2023

Establishing geochronological controls on ancient sedimentary successions is critical for evaluating cause and effect, as well as rates of change, in ancient environments. Towards this goal, U-Pb dating of carbonate phases by in situ LA-ICP-MS offers a rapid and reasonably precise method for evaluating not only depositional ages but also the ages of post-depositional processes affecting carbonate rock. However, this technique is still in its first decade of application to carbonate rocks. Determining the best practices for applying this technique and evaluating the meaning, reliability, and robustness of the data it produces remain areas of interest. In this study, we present the first results from U-Pb dating and geochemical characterization of samples from recent drillcores from Namibia, drilled by International Continental Scientific Drilling Program project GRIND-ECT. GRIND-ECT aims to capture, in drillcore, the Ediacaran-Cambrian transition in key successions worldwide. The Namibian portion of GRIND-ECT targets the Nama Group of southern Namibia, well-known for its abundant fossils and detailed geochemical and geochronological records from outcrop, with the goal of elucidating changes in the Earth system during the diversification of early animals. With both abundant interbedded ashes amenable to U-Pb zircon dating and abundant carbonate, these drillcores offer a natural experiment for comparing results from LA-ICP-MS carbonate dating and other geochronological techniques. Our results show that a significant fraction of samples yield geologically meaningful ages when dated using LA-ICP-MS. These ages are consistent with depositional or early post-depositional ages. Microbially-influenced facies are often the most successful. Theses ages can be further refined using higher-precision techniques. Efforts to date vein calcites, which are often very low in U, have not yet yielded robust ages. Integration of Sr and trace and rare earth element data indicate the promise and the limitations of using these proxies as tests for “datability.”
Effects of the Indian Ocean Monsoon oscillation during the Pleistocene-Holocene transition on the palinomorphic records in the NW Arabian Sea.
Authors: Rodrigues Patricia , Behling Hermann , Hoffmann Gösta , Bauer Wilfried
Published: February 2023

The Indian Ocean Monsoon is one of the largest land-ocean coupled events on Earth. Its occurrence is not only of climatic importance but also has a considerable economic impact on the livelihood of people/countries within its coverage zone. The monsoon winds travelling over the Arabian Sea (AS) carry moisture and bring rainfall to the southern part of the Sultanate of Oman and over a broad area of the Indian continent. In addition to rainfall, the monsoon also causes an intense and extensive deep-water upwelling along the coast and offshore of East Africa and the southern Arabian Peninsula. This intense and pronounced upwelling increases the productivity turning the western Arabian Sea into one of the most productive regions in the world.  In this poster we display partial results of a high-resolution study aiming at identifying monsoonal climatic changes recorded in marine sediments from the northwestern Arabian Sea during the late Pleistocene-Mid Holocene. It was carried out on 11 samples taken from an offshore core IODP Leg 117-721A-1H-1-W. An interval from 80 to 30 cm has been selected and samples have been taken every 3 cm.  We show here results obtained from 6 radiocarbon dating together with the study of palynomorphs. The main objective is to qualitatively identify and characterize pollen grains and spores, as well as the non-pollen palynomorphs (NPP) present in the samples, correlating them with other study sites in the AS. In addition, we evaluate their potential as paleoenvironmental indicators. Samples have presented a low number of pollen grains and spore, which has ranged from 3 to 27 identified specimens. The deeper/older samples have presented a higher concentration of pollen grains. However, due to the low content of specimens, quantitative paleoenvironmental conclusion could not be drawn. Nonetheless, non-pollen palynomorphs are relatively abundant throughout samples. Dinocysts represent the most abundant type of NPP, followed by fungi, microscopic remains of algae and others still not identified. Palynological studies carried on the NW Arabian Sea are scarce and NPP identification and characterization have not been done at the study site yet. Therefore, our work presents novelty on recognizing palinomorphic imprints left by Indian Ocean Monsoon oscillation during the transition Pleistocene-Holocene off the Omani coast.
Aggregate structure destruction and pore plugging caused by raindrop splashes
Authors: Li Guanglu
Published: February 2023

Raindrop splash engenders the dispersion and transport of the soil particles,  that is the primary stage in the process of soil erosion. Raindrops with different diameters may have different influences on different soil structures. The research objective was to quantitatively and visually analyze the change in surface aggregates and pore microstructure of five soils (Eum-Orthic Anthrosol, Ustalf, Cumulic Haplustoll, Ustochnept and Quartisamment) in the Loess Plateau caused by various raindrop diameters (2.67, 3.39 and 4.05 mm) using rainfall tests, synchrotron-based X-ray micro-computed tomography (SR-μCT) and digital picture processing. Surface aggregate fragmentation and pore plugging rose as growing raindrop diameter. Under raindrop splash, the increase in raindrop diameter increased the number of microaggregates (≤ 250 μm) of Cumulic Haplustoll, Ustalf and Eum-Orthic Anthrosol; the irregular pore-shape factor of Quartisamment and Ustochnept; and the total number of aggregates and pores. Moreover, the soil physicochemical properties also had a significant impact on surface aggregate breakdown and pore plugging (P < 0.01). Higher sand contents made the soil structure of Quartisamment and Ustochnept more susceptible to splashing. The FD of Eum-Orthic Anthrosol, Ustalf and Cumulic Haplustoll were lower than those of Quartisamment and Ustochnept. The results showed that during rainfall, both raindrop diameter and soil properties affect surface aggregate stability and pore connectivity, which creates the material basis for forming surface crust, clogging pores and reducing the infiltration rate.
Enhancement of cloud glaciation and rain frequency by airborne pollen
Authors: Kretzschmar Jan , Wirth Christian , Pöhlker Mira , Stratmann Frank , Wex Heike , Quaas Johannes
Published: February 2023

Pollen belong to a subset of atmospheric aerosol particles that enable the glaciation of supercooled liquid water, which is present in clouds down to an ambient temperature of -38°C. While the ice nucleating properties of pollen are widely researched in laboratory studies, it is challenging to evaluate their effect on clouds in observations at a large scale. Using a combination of ground-based measurements of pollen concentration and satellite observations of cloud properties during springtime, we show that the ice nucleating properties of pollen promote the glaciation of supercooled liquid water. We further establish the link between the pollen-induced increase in cloud ice to a higher precipitation frequency. In light of anthropogenic climate change, the extended and strengthened pollen season and alterations in biodiversity can, therefore, introduce a localized climate forcing and a modification of the precipitation frequency and intensity, especially during springtime.
New Resources promoting the GEO Data Sharing and Management, FAIR, and CARE principles
Authors: Voidrot Marie-Francoise , Lijla Bye Bente , de Salvo Paola , Franziskakis Florian , Benedict Karl , Maso Joan , Schubert Chris , Rubio Jose Miguel , Downs Robert R.
Published: February 2023

In September and October 2022, the Group on Earth Observations (GEO) Data Working Group implemented a dialogue series to raise awareness about the GEO Data Sharing and Data 
Management Principles and their benefits with special attention to usability and legal aspects of in-situ and remote sensing Earth Observation data. The intended dialogues’ audience included all Earth observation stakeholders, including data producers, technology providers, scientists, researchers, business developers, decision-makers, and policymakers. Each session covered the theory of the core topic and provided examples of existing implementations.  Leaders and experts presented, via short lightning talks, success stories related to in situ and remote sensing data, the GEO Data Sharing and Data Management Principles, and the FAIR, TRUST, and CARE principles. The diversity of the success stories related to different thematic domains and data types, fostering cross-innovation, and highlighting proven solutions - all serving to introduce discussions. Members of the Earth observation community shared their experiences in implementing the principles, discussed how they tackled challenges and described impacts. The covered topics addressed the data life cycle, the GEO Data Sharing Principles, and the GEO Data Management Principles; elements of Discoverability, Accessibility, Usability (Encoding, Documentation, Provenance, Quality Control), Preservation (Preservation, Verification); Curation (Review and processing, Identifiers); as well as the Data Management Self-Assessment Tool. Standards are instrumental for implementing data management best practices. Broadly sharing a common baseline of understanding and references, the dialogues support community engagement and interoperability. The dialogue series contributes to capacity development on data management in general. All materials, including recordings and presentations, are available on the GEO Knowledge Hub, Youtube, and are open to sharing on other community portals. This communication will present examples of implementations of the GEO DMP extracted from the dialog series as well as new dialogues that will be developed in 2023, with special attention to in-situ data challenges and integration with other data in global solutions.
Climatic water balance in Poland – intraannual variability and longterm trends
Authors: Wibig Joanna , Jędruszkiewicz Joanna
Published: February 2023

On the basis of data from the period 1966-2020 from about 50 stations in Poland the precipitation and potential evaporation indices will be estimated and their variability analyzed. Different formulas of potential evapotranspiration, based on air temperature, relative humidity, saturation deficit, wind speed and/or sunshine duration, will be compared. Climatic water balance defined as a difference of precipitation and potential evapotranspiration will be calculated and its intraannual variability analyzed. Long-term changes of all three parameters (precipitation, evapotranspiration and climatic water balance) in the context of contemporary warming will be examined. On this basis, the problem of water availability in various regions of the country will be discussed, especially in the context of changes in the spatial distribution and duration of the snow cover. 
Evaluation of GEOS-Chem model performance for simulating transport and deposition of cosmogenic 10Be and 7Be using different production models
Authors: Zheng Minjie , Liu Hongyu , Adolphi Florian , Muscheler Raimund , Lu Zhengyao , Wu Mousong , Prisle Nønne
Published: February 2023

The cosmogenic radionuclides 7Be and 10Be are useful aerosol tracers for atmospheric transport studies. Combining 7Be and 10Be measurements with an atmospheric transport model, not only can improve our understanding of the radionuclide transport and deposition processes, but also can provide an evaluation of the transport process in the model. To simulate those aerosol tracers, it is critical to evaluate the influence of production uncertainties in simulations. Here we use the GEOS-Chem transport model to simulate 7Be and 10Be with different production scenarios: the default production scenario in GEOS-Chem based on an empirical approach, and two production scenarios from the CRAC: Be (Cosmic Ray Atmospheric Cascade: application to Beryllium) model. The model results are comprehensively evaluated with a large number of measurements including more than 490 sites for surface air concentrations and 300 sites for deposition flux. The model can reproduce the absolute values and temporal variability of 7Be and 10Be surface concentrations and deposition fluxes on annual and sub-annual scales. The simulations using the CRAC production scenarios yield a better agreement with the measured deposition flux (70% of data within a factor of 2) compared to the default production scenario in the GEOS-Chem model (59%).  This better agreement is also observed for the vertical profiles of air 7Be concentrations.  Independent of the production models, surface air concentrations and deposition fluxes from all simulations show similar seasonal variations, suggesting a dominant meteorological influence. Finally, we demonstrate the importance of including time-varying solar modulation in the production calculation, which can significantly improve the agreement between the model and measurements, especially from mid to high latitudes.
A Critical Analysis of Optimal Fingerprinting Methods for Climate Change through the Lens of Linear Response Theory
Authors: Lucarini Valerio , Chekroun Mickaël D.
Published: February 2023

Detection and attribution studies have played a major role in shaping contemporary climate science and have provided key motivations supporting global climate policy negotiations. The goal of such studies is to associate observed climatic patterns of climate change with acting forcings - both anthropogenic and natural ones - with the goal of making statements on the acting drivers of climate change. The statistical inference is usually performed using regression methods referred to as optimal fingerprinting. We show here how a fairly general formulation of linear response theory relevant for nonequilibrium systems provides the physical and mathematical foundations behind the optimal fingerprinting approach for the climate change detection and attribution problem. Our angle allows one to clearly frame assumptions, strengths and potential pitfalls of the method.  
Towards a benchmark dataset for statistical downscaling of meteorological fields
Authors: Langguth Michael , Gong Bing , Ji Yan , Schultz Martin G. , Stein Olaf
Published: February 2023

The representation of the atmospheric state at high spatial resolution is of particular relevance in various domains of Earth science. While global reanalysis datasets such as ERA5 provide comprehensive repositories of meteorological data, their spatial resolution (∆x≥25 km) is too coarse to capture relevant local features, mainly over complex terrain (e.g. cold pools in valleys, low-level jets, local heavy precipitation events).Recently, various studies have started to apply deep neural networks adapted from computer vision to increase the spatial resolution of meteorological fields. Although these studies reveal great potential in the domain of statistical downscaling, intercomparison of the approaches is impeded due to a large variety of methods and deployed datasets. Comparisons to classical downscaling methods developed for decades in the meteorological community are also often underrepresented.Inspired by the available benchmark datasets for various computer vision tasks and for weather forecasting (e.g. WeatherBench and WeatherBench Probability), our study aims to provide a benchmark dataset for statistical downscaling of meteorological fields. We choose the coarse-grained ERA5 reanalysis (∆xERA5≃30 km) and the fine-scaled COSMO-REA6 (∆xCREA6≃6km) as input and target datasets. Both datasets enable the formulation of a real downscaling task: super-resolve the data and correct for model biases.The benchmark dataset provides a collection of predictors and predictands for a couple of standard downscaling tasks. These comprise downscaling of the 2m temperature, the surface irradiance, the near-surface wind field and precipitation. Along with the dataset, benchmark deep neural networks, namely variants of U-Nets and GANs, will be provided. Well-chosen sets of evaluation metrics including baseline scores of the benchmarked deep neural networks are presented to enable comparison between different methods.The envisioned benchmark dataset will provide a comprehensive basis for comparing neural network approaches on statistical downscaling of meteorological fields. This, in turn, is considered to enhance confidence and transparency in the application of deep learning methods on Earth system problems.
Modeling downwelling longwave irradiance at daily resolution under all skies: A cloud-free approach
Authors: Bright Ryan , Eisner Stephanie
Published: February 2023

Downwelling longwave irradiance (LW↓) is challenging and expensive to measure and is often estimated indirectly with parametric modeling of routinely measured surface-level meteorological variables.  Modeling LW↓ under all-sky conditions typically involves “correcting” a clear- (or non-overcast) sky model estimate using solar-irradiance-based proxies of cloud cover in lieu of actual cloud cover given uncertainties and measurement challenges of the latter.  While such approaches are deemed sound, their application in time and space is inherently limited.  Here, we present a correction model free of cloud variables applicable at the true daily (24-hr.) and global scale that – irrespective of the underlying clear-sky model – yields errors over land that are lower than those from stand-alone models and on par with daytime errors from the prevailing solar-based cloud proxy corrections (rRMSD = ~7%; rMAD = ~5.5%).  We document and critically assess its performance over land and ocean independently, as well as in high elevation and cold environments representing two notoriously challenging conditions.  The cloud-free correction is found to perform better than stand-alone approaches at all subsets; however, within-subset performance differences were evident and attributable to the underlying clear-sky model, reinforcing previous findings surrounding performance thresholds of parametric models with globally-tuned parameters. 
The second generation of the Levantine Archaeomagnetic Curve (LAC.v.2.0) ~6300 BCE - 300 CE: Insight into the evolution of the Iron Age anomaly, geomagnetic spikes and secular variation rates
Authors: Shaar Ron , Gallet Yves , Ben-Yosef Erez , Vaknin Yoav , Hassul Erez , Bar Sovik Lior
Published: February 2023

The vast number of well-dated archaeological sites in the Levant and Mesopotamia, provide a unique opportunity for detailed archaeomagnetic research. In an effort to exploit the full archaeomagnetic potential of this region, we assemble an archaeointensity compilation based on two separate datasets which were constructed independently in different regions using different methods. The Mesopotamian dataset, comprised of 123 groups of samples (fragments) collected from Syria and north-western Iraq was analyzed for the most part using the Triaxe method. The Levantine dataset comprised of more than 150 groups of samples collected from Israel was analyzed using Thellier-IZZI-MagIC method. Together, these partially overlapped datasets compose a continuous record that spans over more than six millennia - from ~6300 BCE to 300 CE. Some intervals in this time span, such as 2000 BCE - 500 BCE and 300 BCE- 300 CE, include at least one context per century with a secure absolute age, which is based on radiocarbon or clear historically-dated events, providing sub-centennial temporal resolution. With these data we construct the second generation of the Levantine Archaeomagnetic Curve (LAC.v.2.0) that enables robust high-resolution analysis of the rates and amplitudes of geomagnetic secular variations. The LAC exhibits four geomagnetic spikes associated with the Levantine Iron Age Anomaly (LIAA), between 1050 and 600 BCE, with virtual axial dipole moment (VADM) reaching values of 155-162 ZAm2 - higher than predicted by currently reconstructed geomagnetic field models. Rates of VADM change associated with the four spikes are ~0.7-1.1 ZAm2/year – at least twice the maximum rate inferred from direct observations, which began ~190 years ago. The increase leading to the first spike from ~1750 BCE to ~1050 BCE depicts the Holocene largest change in field intensity. The highest value in the LAC is more than 3 times greater than the lowest value providing conservative bounds for the local variability of the geomagnetic field. Finally, we present a new compilation of archaeomagnetic directions obtained from 70 structures in Israel which, together with the intensity curve, provide a further step towards a full-vector description of the field.
Waterlogging and Drainage Congestion in the Kosi Fan of theHimalayan Foreland
Authors: Naik M Nniranjan , Singh Amrit Kumar , Singh Abhilash , Gaurav Kumar
Published: February 2023

This study uses optical and radar satellite images (i.e., Landsat and Sentinel-1 & 2) to monitor seasonal waterlogging in the Kosi Fan from the 1987-2021 period. We used Google Earth Engine (GEE) platform to process the satellite images. We applied Random Forest (RF) classifier to classify the image pixels that correspond to waterlogging from optical and microwave images. The optical images detect the waterlogging patches more accurately (70-80%) as compared to the radar images (50-65%). We observed that the waterlogging patches located along the road and stream networks show a high probability of occurrence. We have computed the probability of occurrence of waterlogging patches near the road and stream network intersection. The result indicates a high correlation of the occurrences of waterlogging patches in the proximity of structural interventions (rail, road, network embankment, etc) on the Kosi Fan.
High-resolution gridded dataset of precipitation and temperature for Trentino-Alto Adige
Authors: Dhawan Pranav , Dalla Torre Daniele , Menapace Andrea , Majone Bruno , Righetti Maurizio
Published: February 2023

A high temporal (hourly) and high spatial resolution (250-meter) multi-decadal (1991 - 2021) gridded dataset of mean temperature and precipitation is presented for the complex mountain area of Trentino-Alto Adige in the north-eastern region of the Alps in Italy. This dataset was obtained from more than 300 meteorological stations covering the entire region of Trentino-Alto Adige as well as the neighbouring countries and regions of Italy. The observed dataset underwent quality checks and quality control such as gross error limit check, two-sided continuity check, persistence check and others for both meteorological variables however, no gap-filling procedure was undertaken in order to keep the originality of the dataset. Using the processed dataset, kriging interpolation technique was used to generate a gridded hourly dataset of the meteorological metered variables on a high spatial resolution grid of 250m x 250m. The accuracy of the kriging dataset was evaluated by a leave-one-out cross-validation approach, wherein the station in consideration is omitted, to remove self-influence, and the time series is reconstructed using the neighbouring stations. For the entire time period and region, the hourly temperature and precipitation show no bias, with a mean absolute error (MAE) of about 1.2 °C and 0.1 mm, comparable with state-of-art high-resolution datasets. This new dataset provides valuable insight into the spatio-temporal distribution of temperature and precipitation for highly variable topography experiencing distinct climatic conditions for the region of Trentino-Alto Adige and it helps to validate climate models for monitoring climate change at the regional level. Moreover, gridded datasets support the modelling of extreme events and climate variance, which are crucial for a range of climate impact assessments.
Quantifying Geodynamical Influences through Physics-Based Machine Learning: A Case Study from the Alpine Region
Authors: Degen Denise , Kumar Ajay , Cacace Mauro , Scheck-Wenderoth Magdalena , Wellmann Florian
Published: February 2023

Characterizing the influence of geodynamical models is important to improve our understanding of the development and current state of subsurface properties. Which are, in turn, of great societal relevance, for questions such as renewable energy. However, enabling a quantifiable characterization is a major challenge in Geodynamics, due to the high computational cost associated with both the model and the analysis for characterizing the influential parameters. The high cost of the model is caused by a high dimensionality in space, and time and a large number of input parameters. The cost of the probabilistic analyses is related to the large number of individual model solves required for performing the characterization.To address this computational challenge, we employ the non-intrusive RB method, which combines advanced mathematical algorithms and novel machine learning methods. The method produces models that considerably reduce the dimensionality, yielding an acceleration of several orders of magnitude while maintaining the physical principles. In contrast, to other machine learning methods, the non-intrusive RB method produces explainable models, which is a crucial property for later analyses and predictions.In this work, we demonstrate how the methodology can be beneficially used for the construction of reliable surrogate models of large-scale geodynamical applications without impacting the underlying physics. Furthermore, we show the benefits of global variance-based sensitivity analysis to quantifiable characterize the influence of the densities and viscosities on both the topography and velocity for the designated case study of the Alpine Region. We employ a global sensitivity analysis to account for possible parameter correlations and nonlinearities.
Characterization and Evaluation of Long-term Air Quality Across Urban Hong Kong
Authors: Han Shuwen , Tan Yan , Lee Shun-cheng
Published: February 2023

Air pollution is a serious environmental issue and has attracted much attention owing to the rapid urbanization and industrialization worldwide. Hong Kong, one of the well-developed cities located in the southeast of the Pearl River Delta (PRD) region, struggling with frequent air pollution episodes because of the intensive land use, dense daily anthropogenic activities, and enormous vehicle emissions. Therefore, a 10-year evaluation of air pollutants across roadside, urban and background sites was conducted to analyze the variations of air quality and contamination in Hong Kong. The continuous decrease of annual averaged concentrations of traffic-related NO2, SO2, CO, PM2.5 and PM10 and numbers of days with severe pollution conditions validated the efficiency of the series of air pollution control schemes implemented by the Hong Kong government. However, the concentration of O3 at roadside and urban stations increased by 135% ± 25% and 37% ± 18% from 2011 to 2020, respectively, meanwhile the highest 8-hour averaged O3 concentration was observed as 294 μg/m3 at background station in 2020, which pointed out the worsening ozone pollution in Hong Kong. To further investigate typical precursors of ozone and secondary organic aerosols, the intensive measurements of VOCs and OVOCs were conducted at both urban roadside station with heavy traffic and coastal station in suburban area to study the chemical compositions and emission patterns of ambient VOCs and OVOCs thoroughly. Results from those two campaigns showed significant differences across Hong Kong. Acetone, formaldehyde, and acetaldehyde were the most abundant species at roadside environment, while formaldehyde, methanol and acetone were the major species in suburban atmosphere. The major contributors to ozone formation were formaldehyde (89.64 μg/m3) at roadside and isoprene (13.46 μg/m3) at suburban among the measured VOCs in Hong Kong. In addition, the source apportionment results from positive matrix factorization (PMF) analysis showed that the sampling site at the southeastern tip of Hong Kong was strongly influenced by urban plumes from the PRD region and by oceanic emissions as well.
Potential changes of finfish thermal habitat under negative emissions
Authors: Goris Nadine , Schwinger Jörg , Fransner Filippa , Fröb Friederike , Lauvset Siv
Published: February 2023

The Paris Agreement has set out the aim to limit global warming to 1.5°C to reduce the risks of climate change. Yet, global carbon emissions continuously increase, such that the option of “negative emissions” – removing CO2 from the atmosphere and storing it on land, underground or in the oceans - is discussed to delay the transition to a zero-carbon society. Among the options discussed are pathways where the 1.5°C temperature goal is temporarily overshot, while negative emissions are subsequently applied to return to a “safe” climate state.  

However, such overshoot strategies might have adverse effects. A previous study showed that a delayed removal of CO2 does not simply lead to a warming while CO2 is increasing, a cooling while CO2 is decreasing and a subsequent steady atmospheric temperature but to a trajectory of warming-cooling-warming. As this response is related to the model´s sensitivity of the Atlantic large-scale ocean circulation, the amplitude of the warming-cooling-warming is most pronounced in the North Atlantic. Here, we extend this study to analyse the impact of the warming-cooling-warming trajectory on Finfish species that are commonly used for Aquaculture, that is Atlantic salmon, gilthead seabream and cobia. Via thermal windows of potential growth ranging from optimal to lethal conditions, we identify temporal fluctuations in the extent of optimal habitats. We anticipate that a more pronounced warming-cooling-warming amplitude exacerbates challenges for the considered species, such that northern habitats are threatened more than southern habitats. We analyse this potential north-south divide in terms of economic and ecological consequences. 