bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of salt supply, dissolution, and erosion on the surface deformation of emergent salt diapirs based on analysis of Persistent Scatterer Interferometry data
Authors: Zebari Mjahid , Friedrich Anke , Rieger Stefanie , Plattner Christina , Brcic Ramon , Závada Prokop
Published: February 2023

In the emergent (subaerial) salt diapirs, the salt faces negative buoyancy when extruded to the surface, and flows outward around their vent by gravity spreading. It also faces dissolution and erosion. Salt supply, salt flow, dissolution, and erosion also influence the diapir’s shape. Although satellite geodesy monitors the surface deformation of the salt-caprock glacier system, the interpretation of the resulting deformation pattern in terms of salt supply, dissolution, and erosion is not straightforward. To overcome these shortcomings, we analyze surface deformation pattern of a fountain-shaped and nearly symmetrical diapir (Finu) within the Zagros Belt of Iran using Persistent Scatterer Interferometry (PSI). The PSI data are extracted from the Sentinel-1 SAR images using the Integrated Wide Area Processor (IWAP) at the German Aerospace Center (DLR) covering four years from October 2014 to December 2018. The line-of-sight signal from the PSI data is decomposed into the vertical and horizontal deformation signals. Within the diapir, the deformation signal is then spatially correlated with the influencing factors, including local position within the diapir, slope, karstification, and drainage. Along an E-W profile across the diapir, two-dimensional deformation vectors reflect salt supply and spreading; therefore, the magnitude and direction of these vectors are influenced by their local position within the diapir and the slope. There is a slight uplift in the central part of the salt domes with active salt extrusion. The deformation vectors divert outward in the slope direction, and the deformation reaches its maximum magnitude at the upper flanks of the central dome. The deformation decreases in the outer flat plateau regions of the extrusions and continues to decrease in the steep slopes at their lateral terminations. Along the same profile, relatively higher subsidence is detected in areas where sinkholes are abundant. In these regions, salt is removed in the subsurface by dissolution-driven karst development in contrast to areas where the surface drainage system is developed, and fluvial erosion is dominant. In the future, a better understanding of the factors controlling salt spreading around the vent and the impacts of dissolution/erosion mechanisms on the deformation will improve our ability to interpret surface deformation of the salt-caprock system at unprecedented spatial and temporal resolution.
Fire emission estimates for Australian extreme fire season 2019/2020 using FLEXPART
Authors: Dillerup Ines , Lüken-Winkels Christopher , Metz Eva-Marie , Vardag Sanam , Deutscher Nicholas , Griffith David , Butz André
Published: February 2023

In Australia, increasing temperatures and prolonged drought periods lead to an intensification of wildfires. In particular, severe fires are expected to occur more frequently in Southeast Australia’s eucalyptus forests leading to strongly enhanced CO2 emissions and preventing the renewed uptake of the released CO2 by vegetation. However, current fire emission estimates presented by conventional fire emission databases show significant discrepancies in their emission estimates of extreme fire events like the Australian fire season 2019/2020.Here, we investigate the fire emissions released during the Australian summer 2019/2020 based on total column measurements of CO2 and CO using the Lagrangian Particle Dispersion Model FLEXPART. We calculate footprints and backward trajectories of trace gases to inversely retrieve carbon emission estimates. In a first case study we focus on TCCON total column measurements of CO and CO2 taken in Wollongong located close to the hot-spot of eucalyptus fires. As the measurements show a significant enhancement of all mentioned tracers during the fire event, FLEXPART is used to calculate emission estimates for southeast Australia. Furthermore, we retrieve emission factors between the trace gases. Our results are compared to the conventional databases like GFED, GFAS and FINN and emission estimates published by other studies.
Active extensional tectonics along the Mirabello Gulf – Ierapetra Basin depression (Eastern Crete, Greece)
Authors: Soukis Konstantinos , Lozios Stelios , Vasilakis Emmanuel , Antoniou Varvara , Laskari Sofia
Published: February 2023

The present-day geotectonic regime of Crete Island is mainly controlled by the processes occurring along the seismically active Hellenic subduction zone, e.g., the fast convergence between Africa - Eurasian plates (at a rate of 36 mm/yr) and the simultaneous SSW-ward retreat of the subducting slab. The result is a large south-facing orogenic wedge extending from the southern coast of Crete up to the Hellenic subduction trench to the South. Contractional structures (thrusts, folds, and duplexes) have formed in the deeper parts of the wedge and caused the thickening of the crust. This has led to substantial regional uplift and extension of the upper part of the wedge. Hence, two significant arc-parallel and arc-normal sets of active normal faults crosscut the Cretan mainland, affecting the entire alpine nappe pile. These faults have created a characteristic basin and range topography expressed through impressive E-ESE and N-NNE horst and graben structures bounded by fault zones with segments ranging from 5 to more than 20 km. Detailed fault mapping of the Mirabello Gulf – Ierapetra Basin depression revealed a dominant NNE-SSW fault system, occupying the central and northern part, and a subordinate E-W to ESE-WNW system, observed mainly along the southern coastal zone. In the ESE margin, the deformation is localized mainly along the 30 km long NNE-SSW Kavousi – Ieraptera fault zone. On the other hand, in the WNW margin, the deformation is distributed in a larger population of relatively minor faults, organizing in more complex second-order horst and graben structures. In the southern part of the Ierapetra Basin, the E-W to ESE-WSW faults are significantly less and concern 2-3 specific zones. Specific morphological structures such as the remarkable range high, the deep V-shaped gorges, the large scree thickness, and the prominent post-glacial fault scarps produced along the basin margins indicate the intensive activity of these faults during the Quaternary. The NNE-SSW fault system seems to be younger and more active, given that i) intersects the E-W or ESE-WNW faults of the southern part, ii) produces significant fault scarps and polished fault surfaces in the cemented scree along the fault zone, and iii) kinematically is compatible with the recent and present-day focal mechanisms (e.g., the 2021 Arkalochori earthquakes). In conclusion, the Ierapetra Basin has formed and developed through an overall E-W extension parallel to the present-day geometry of the arc.
Near-surface seismic characterisation of a railway embankment slope using fibre-optic distributed acoustic sensing
Authors: Maggio Giuseppe , Trafford Andrew , Donohue Shane
Published: February 2023

The behaviour of geological slopes during seasonal weather patterns represents one of the challenges for assessing the geotechnical state of health of the ageing infrastructures. In the presence of man-made soil infrastructure slopes, rainfall and prolonged dry periods can cause cycles of swelling and shrinking of the ground that could potentially compromise their structural integrity. Recent research has found that time-lapse velocity monitoring, has the potential to provide information on climate-related deterioration of geotechnical infrastructure. Variations of the ground conditions could manifest as changes in seismic velocity, detectable through the seasons and after extreme weather events.In this work, we perform seismic imaging and velocity-monitoring of a critical railway embankment in the United Kingdom using fibre optic distributed sensing (DAS). The study area is a 6 m tall, and 350 m long embankment slope built more than 100 years ago in the outskirts of London (Surrey). The railway is currently utilised mostly by commuter trains. Since August 2022, a passive DAS dataset rich in train signals has been acquired. data acquisition will continue until July 2023. Furthermore, periodic active surveys have been conducted along the slope.Firstly, to validate the seismic response of the fibre (i.e., maximum usable frequencies based on the gauge length), we calculate and compare surface wave dispersion curves derived from both DAS and geophones using passive ambient noise, train signals and active sledgehammer shots. As a result, we obtain consistent and comparable dispersion curves ranging from ~200 m/s at 10 Hz to ~140m/s at 40 Hz. Secondly, we invert, using global search algorithms, DAS-derived dispersion curves for 1D depth-velocity models to identify and clarify the trend of the near-surface (top 10 m) seismic structures. Thirdly, we apply seismic interferometry and moving window cross-spectral techniques to measure changes in seismic velocity at the embankment using the 6-month passive DAS data acquired so far. The ultimate goal of this project is to develop a geophysical tool diagnostic of geotechnical deterioration of critical infrastructures by linking together DAS-based seismic observations, temporal seismic velocity changes, weather data and laboratory-based soil sample tests.
Triple oxygen isotope analyses of carbon dioxide, water and carbonates by VCOF-CRDS technique
Authors: Chaillot Justin , Daeron Mathieu , Casado Mathieu , Landais Amaelle , Pesnin Marie , Kassi Samir
Published: February 2023

Oxygen-17 excess (Δ17O) in carbonate minerals can provide valuable insights into past continental and marine environments, long-term trends in the temperature and oxygen-isotope composition of ancient oceans, isotopic disequilibrium effects in biogenic and abiotic carbonates, and cryptic diagenesis. Triple oxygen isotope analyses of carbonates and/or CO2 using isotope-ratio mass spectrometers (IRMS) remain challenging, however, because of isobaric interference between 16O13C16O and 16O12C17O. Using spectroscopic methods, the abundance of each CO2 isotopologue may be directly quantified, potentially providing simple, non-destructive measurements of δ13C, δ18O and Δ17O on small samples of CO2.Here we report new data characterizing the application of VCOF-CRDS (V-shaped Cavity Optical Feedback - Cavity Ring Down Spectroscopy [1]) to the analysis of small samples (<40 μmol) of pure CO2, as typically produced by phosphoric acid digestion of carbonate minerals.Instrumental drifts from various sources are observed to bias apparent isotopic abundances by a few tens of ppm, but these drifts are slow enough that they may be precisely monitored and corrected for by repeated analyses of a working gas interspersed between other analyses, requiring only ~8 mn per aliquot and 30 mn between consecutive “unkown” analyses. This approach was tested by analyzing repeated aliquots of another CO2 tank with a different isotopic composition, yielding instrumental repeatabilities of 12 ppm, 13 ppm and 7.4 ppm for δ13C, δ18O and Δ17O, respectively (95 % CL, Nf = 66).The accuracy of our measurements was tested over a wide range of Δ17O values spanning 130 ppm, by analyzing CO2 equilibrated at 25 °C with different waters whose triple oxygen compositions were independently constrained in the SMOW-SLAP scale by IRMS measurements and by simple nonlinear mixing predictions. We find that our Δ17O measurements are well within analytical uncertainties of predicted values (RMSE = 1.2 ppm), with analytical repeatabilities (including isotopic equilibration and gas manipulation) of 8.6 ppm (95 % CL, Nf = 27).We will also report the results of our ongoing investigation regarding the isotopic fractionation and analytical noise associated with different acid digestion protocols at different reaction temperatures, and the triple oxygen composition of various international reference materials already used for δ13C, δ18O, and clumped-isotope measurements.Based on these results, we conclude that VCOF-CRDS offers excellent accuracy, along with state-of-the-art levels of analytical precision/linearity, for straightforward analyses of 17O excess in CO2, water, and carbonate minerals.[1] Stoltmann et al. (2017) 10.1021/acs.analchem.7b02853
Bias correction of aircraft temperature observations in the Korean Integrated Model based on a deep learning approach
Authors: Kwon Hui-nae , Jeon Hyeon-ju , Kang Jeon-ho , Kwon In-hyuk , Park Seon Ki
Published: February 2023

The aircraft-based observation is one of the important anchor data used in the numerical weather prediction (NWP) models. Nevertheless, the bias has been noted in the temperature observation through several previous studies. As the performance on the hybrid four-dimensional ensemble variational (hybrid-4DEnVar) data assimilation (DA) system of the Korean Integrated Model (KIM) ⸺ the operational model in the Korea Meteorological Administration (KMA) ⸺ has been advanced, the need for the aircraft temperature bias correction (BC) has been confirmed. Accordingly, as a preliminary study on the BC, the static BC method based on the linear regression was applied to the KIM Package for Observation Processing (KPOP) system. However, the results showed there were limitations of a spatial discontinuity and a dependency on the calculation period of BC coefficients.In this study, we tried to develop the machine learning-based bias estimation model to overcome these limitations. The MultiLayer Perceptron (MLP) based learning was performed to consider the vertical, spatial and temporal characteristics of each observation by flight IDs and phases, and at the same time to consider the correlation among observation variables. As a result of removing the predicted bias from the bias estimation model, the mean of the background innovation (O-B) decreases from 0.2217 K to 0.0136 K in a given test period. Afterwards, in order to verify the analysis field impact for BC, the bias estimation model will be grafted onto the KPOP system and then several DA cycle experiments will be conducted in the KIM.
Advancing the Support to the Radionuclide Monitoring Verification Technology of the CTBT with the 1st Nuclear Explosion Signal Screening Open Intercomparison Exercise 202
Authors: Schoemaker Robin , Kusmierczyk-Michulec Jolanta , Liu Boxue , Tipka Anne , Kijima Yuichi , Bare Jonathan , Kalinowski Martin , Maurer Christian , Skomorowski Paul , Hieden Alexander , Arnold-Arias Delia , Sarathi Ramesh , Schrom Brian , Mendez Jennifer , Brioude Jerome
Published: February 2023

Radionuclide monitoring is one of the verification technologies of the global verification system of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). This global network of sampling stations senses the air 24/7 for suspect noble gases and/or particulates. For noble gases this task is non-trivial due to the ever-present and highly variable background levels of the four radioxenon isotopes that are relevant for CTBT monitoring. An extensive, global effort was initiated to better estimate the civil radioxenon background based on known sources and end up with a more reliable event screening. This challenge, called “1st Nuclear Explosion Signal Screening Open Inter-Comparison Exercise 2021,” provided an assessment of a chain of multilevel, multidisciplinary scientific analyses and built on three previous atmospheric transport modelling (ATM) Challenges. It’s a first since it explored integrating both ATM and radionuclide statistical expertise to characterize the detection, time, location, and source strength of an anomalous event. The exercise ran through 2022 and was a collaboration between participants from around the world who utilized a comprehensive pre-developed test data set based on explosion release scenarios, xenon measurements and emission inventories, and atmospheric transport data provided by the ATM software FLEXPART. The data set was composed of synthetic activity concentrations of the simulated nuclear explosion signals added to the radioxenon measurements at the International Monitoring Station (IMS). Three levels of participation were offered, requiring different areas of expertise: 1) ATM expertise only, where participants simulated radioxenon background time series at the 23 IMS stations to be used as input for screening synthetic radioxenon measurements based on a set of predefined statistical methods; 2) radionuclide expertise, where participants provided their own methods and results for detection, screening, and timing powers; and 3) higher-level ATM and statistical expertise, where, in addition to Level 2, results were provided for location and magnitude estimates for a few selected test cases. This paper gives a general overview of the exercise and provides highlights and discusses the key results.
How to invest carbon under drought, different strategies in early root system development among barley cultivars
Authors: Germon Amandine , Colombi Tino , Müller-Stöver Dorette , Keller Thomas , Müller Carsten
Published: February 2023

Plant roots exposed to water scarcity respond by modulating root functional traits, such as deep and prolific root growth, to maximize resource acquisition. Such adjustments, which include the alterations of root morphology and anatomy to optimize water uptake and/or maximize root survival, may also increase the carbon demand for soil exploration. But this altered carbon allocation to foster belowground resource acquisition limits aboveground plant development. In the present study we investigated the relationship between root physiology, root trait plasticity and whole plant growth under drought stress. We quantified shoot and root traits of nine contrasting spring barley cultivars grown in soil-filled rhizoboxes under well-watered (4 weeks, 55% of field capacity) or drought conditions (2 weeks, 55% of field capacity + 2 weeks without water). Time-lapse imaging was applied to quantify root and shoot growth rates, and combined with measurements of root distribution, morphology, anatomy as well as mycorrhizal colonization. Aboveground traits had a strong and uniform response to drought compared to belowground traits. Root traits’ plasticity were variable and differed among cultivars. The differences between cultivars were particularly pronounced for the proportion of root length and root biomass in deep soil layers as well as changes in root morphological and anatomical traits. We suggest that cultivars characterized by an increase in root conduits, a greater hierarchical structure and a reduction of specific root length and area may be good candidates to promote hydraulic lift while lowering carbon cost for root growth. Increased root length and depth, root density and specific root length in drought condition are different cultivars’ strategies that may promote soil exploration and optimize water uptake. This is directly linked to the interplay of above and belowground carbon investment, with some cultivars yielding both a high shoot biomass and enhanced resource acquisition. Based on our findings, testing new agronomic strategies to mobilize the diversity of cultivars could be key to enhance drought resistance and resilience of barley cropping systems.
Global and regional marine bromoform emissions in a fully coupled ocean-atmosphere-model
Authors: Booge Dennis , Tjiputra Jerry , Olivié Dirk , Quack Birgit , Schulz Michael , Krüger Kirstin
Published: February 2023

Bromoform (CHBr3) is one of the most important precursors of atmospheric reactive bromine with an atmospheric lifetime of ~20 days. Natural production, being the main source of oceanic CHBr3, is high at the coasts and in open ocean upwelling regions due to production by macroalgae and phytoplankton. Although highly relevant for the future halogen burden and ozone layer in the stratosphere, the global bromoform production in the ocean and their emissions are still poorly constrained in observations and are mostly neglected in Earth System Model (ESM) climate projections.
Here, we show first model results of fully coupled ocean-atmosphere bromoform interactions in the Norwegian ESM (NorESM) with the ocean model BLOM and the ocean biogeochemistry component iHAMOCC for the CMIP6 historical period from 1850 to 2014.
Our results are validated using oceanic and atmospheric measurements listed in the HalOcAt (Halocarbons in the Ocean and Atmosphere) data base and show an overall good agreement with those observations in open ocean regions. The NorESM open ocean emissions of CHBr3 are higher than previously published emission estimates from bottom-up approaches. Moreover, the emissions are mainly positive (sea-to-air fluxes) driven by the oceanic production, sea surface temperature and wind speed, dependent on season and location. However, during low-productive winter seasons, model results also show local negative fluxes (air-to-sea fluxes) in high latitudes, suggesting some oceanic regions to be a sink of atmospheric bromoform. Driving factors will be shown for different case studies, e.g. the tropical West Pacific, which is a hot spot for oceanic bromine delivery to the stratosphere.
Impact of parallax correction on Deep Convection Clouds detection frequency.
Authors: Babicka Zuzanna , Kotarba Andrzej Z. , Wojciechowska Izabela
Published: February 2023

Satellite data is becoming a progressively accurate source of weather information. An increasing resolution and the number of spectral channels allows to determine the location and recognition of clouds due to their optical and thermal properties.Predicting the movement of correctly defined deep convection clouds (DCC) is of great importance in forecasting the course of dangerous phenomena for households as well as human health and life. The analysis of trends and occurrence of DCC will make it possible to verify the current climate models, which estimate that the aforementioned phenomena will intensify in the future.The most common method of detecting DCC is based on the cloud tops temperature. The lower the temperature, the higher and more extensive the cloud is.The aim of the study is to determine the influence of parallax shift on the frequency of deep convection clouds (DCC).A geostationary satellite is located at a fixed point in the orbit, which means that the angle of view at higher latitudes is smaller. The higher the object, the greater the parallax shift of the object in relation to its true location. In order to verify the shift and its significance in the analysis of the trend of DCC occurrence, it is necessary to check what values the shift takes and whether it causes significant losses in the number of detected DCC.The data used for the analysis come from the geostationary satellite Meteosat Second Generation 1 (MSG1) - Meteosat-8, whose sub-satellite point has coordinates: 0oN and 3.4° W. And from the circumpolar satellite Moderate Resolution Imaging Spectroradiometer (MODIS), which it flies at an altitude of 705 km and its cycle lasts 16 days. The cloud tops temperature was obtained from both satellites and used to estimate the cloud tops height.The analyzes were carried out for the case study of July 4, 2005.To perform the parallax correction of the geostationary satellite, the existing parallax correction methods were used. For the first time, an attempt was also made to perform parallax correction for a circumpolar satellite.This research was funded by the National Science Institute of Poland. Grand no. UMO-2020/39/B/ST10/00850.
Effect of thinning on turbulence structure, energy and gas exchange in a boreal forest
Authors: Mammarella Ivan , Thomas Abin , Aslan Toprak , Aalto Juho , Back Jaana , Kolari Pasi , Launiainen Samuli , Peltola Olli , Vesala Timo
Published: February 2023

Thinning is performed primarily to manage between-tree competition and allocate growth-limiting resources (e.g. light, water, nutrients) to the remaining trees and to increase their growth rate and vitality. From biophysical point of view, thinning changes tree spacing, number, and size distribution. Our hypothesis is that altered stand structure and decreased foliage density cause modifications of the microclimate, radiation budget and turbulence characteristics within the canopy. Jointly, these physical constraints change the dynamics of biogeochemical cycles and affect mass and energy exchange between soil and vegetation components and the atmosphere.Here, we investigate the short-term response (i.e. one-two years post thinning) to the thinning done at Hyytiälä forest located in southern Finland. We present results using eddy covariance (EC) fluxes of NEE and ET at both ecosystem level (i.e. above canopy EC) and ground vegetation level (i.e. sub-canopy EC). We found that the forest became a source of carbon during the first post thinning year (+55 gC m-2), while in the second post-thinning year (2021), the ecosystem has only partly recovered showing annual NEE value of -152 gC m-2 which is somehow far from the long-term net uptake measured at the site (-252 gC m-2). Preliminary results show that the thinning had less impacts on ET fluxes. We also report the effect of thinning on ecosystem surface fluxes of carbonyl sulfide (COS), carbon monoxide (CO) and ozone (O3). Here, we hypothesize an increase of CO biogenic emission, due to an increase of amount of litter and light on the forest floor, and a decrease of COS and O3 deposition rates, related to foliage removal.Finally, the functional response of the flux components are analysed by using clustering and modelling approaches in order to disentangle the roles of thinning and weather on measured fluxes and budgets.
Melting properties and melting phase relations of the Martian mantle from in-situ measurements on iron-rich mineralogical assemblages
Authors: Pierru Rémy , Dominijanni Serena , Parisiadis Paraskevas , Andriambariarijaona Léon , Zhao Bin , Blanchard Ingrid , Guignot Nicolas , King Andrew , Badro James , Antonangeli Daniele
Published: February 2023

Mars’ mantle dynamical history has certainly been dominated by a stagnant-lid regime, with limited mixing and homogenization. Accordingly, the chemical and mineralogical signatures of early processes, including the crystallization of a primitive magma ocean, are overall well preserved on Mars. The major geological structures visible at its surface are the remains of an intense ancient volcanism, not so dissimilar from the large igneous provinces found on Earth at very old ages (several million/billion years).Current models used to determine the mantle thermal evolution and the crustal extraction heavily relies on melting properties of materials expected to form the Martian mantle, which, however are poorly known. In particular, the fact that the Martian mantle is probably richer in iron than the terrestrial mantle has a direct impact on the solidus and liquidus and on the chemistry of the magmas that can be produced at different pressures. Thus, the study of Martian volcanism and thermal history requires a precise understanding of the melting properties of the mantle (solidus, liquidus and extent of melting) as a function of pressure and temperature. Studies in literature are scant, mainly address the solidus, and are limited to analysis of recovered samples, missing in situ diagnostics.To address this problem, we studied the solid-liquid melting relations and, more generally, the melting diagram for a mineralogical assemblage model of mantle composition, by high-pressure and high-temperature experiments in multi anvil press performed at the PSICHE beamline of the SOLEIL synchrotron. We determined the solidus and the liquidus of the investigated rock at pressures up to 12 GPa by complementary in-situ diagnostics (X-ray diffraction and falling sphere technic). The obtained solidus and liquidus are well lower (difference >200K), especially at the highest investigated pressures, compared to previous studies, with strong implications for the origin of volcanism and notably the crystallization of the magma ocean. Furthermore, our experiments provide important data to refine the extent of melting (Φ), modal proportion and the chemistry of all the different phases present between the solidus and the liquidus at different conditions (P, T, Φ).Altogether, these new results are critical to constrain models of thermal evolution and crust extraction and formation, as well as to address the evolution of the magmatism and volcanism at the Mars surface since 3.5 Ga. Finally, depending on different parameters, such as the thickness of the crust or the concentration of radioactive elements, the estimated areotherm could cross the solidus and lead to partial melting of the mantle, especially close to the core-mantle boundary, where a high extent of melting could be reached.

 
Jupiter's Atmosphere Profiling
Authors: Benn Mathias , Jørgensen John L. , Jørgensen Peter S. , Denver Troelz , Herceg Matija , Connerney Jack E.
Published: February 2023

The micro Advanced Stellar Compass (µASC), an instrument onboard Juno serving as attitude reference for the Juno Magnetic Field investigation, providing accurate bias free attitude information continuously throughout the mission. The µASC is equipped with four optical sensors, configured for low-light scenarios, which enables detection of stars and objects as faint as 7-8Mv.During each perijove passage the highly elliptical Juno orbit configuration, in combination with the 13° off pointing of the star tracker cameras from the Juno spin axis in the anti-sun direction, enables observations of the Jupiter horizon at a high slant angle. During such observation opportunities, the Jovian horizon is some 40,000km distant, offering detailed imaging of the upper atmosphere, luminous phenomenon herein, as well as any haze layer or elevated clouds, before the planet atmosphere transitions into the dark space star field. The orbital motion of Juno, further result in continuous occultation’s of stars setting behind the horizon.After 40+ perijoves such images have been acquired from the µASC, distributed from Jupiter North Pole down to +30deg of latitude at a wide range of longitudes. This coverage enables altitude profiling of the top atmosphere as described by latitude and longitude for both dusk and dawn conditions of Jupiter.Images and objects observed by the aforementioned technique are presented together with the detected energies within the sensitivity range of the observing star tracker camera and their implications for the atmospheric density profile.
Seismic and infrasound monitoring of military conflicts using machine learning
Authors: Brissaud Quentin , Myklebust Erik , Dando Ben , Goertz-Allmann Bettina , Köhler Andreas , Schweitzer Johannes , Kvaerna Tormod
Published: February 2023

The real-time seismo-acoustic monitoring of military conflicts can provide a unique alternative to conventional ground reports and sparse satellite coverage. The pressure waves generated by an explosion travel through the atmosphere and subsurface as sound and seismic waves, and their signature can be recorded by arrays of seismometers for ground motion or microbarometers for sound propagation. However, standard monitoring techniques can be both computationally expensive when localizing signals over large regions and/or prone to false detections when signals have low amplitudes. In this contribution we propose a Machine-Learning (ML) based solution to detect seismic and infrasound arrivals and locate sources close to real time. To validate our model we leverage the seismic data collected during the Russia-Ukraine conflict started in February 2022 using the Ukrainian primary station of the International Monitoring System (IMS), the Malin array (AKSAG). We test both the accuracy and computational efficiency of our approach against a threshold-based migration stacking model developed for near-real time monitoring in Ukraine. We hope that this first-ever ML detector of both seismic and acoustic phases could be employed for real-time monitoring of conflicts around the world across different network geometries and noise conditions.
Examination of ITS_LIVE ice velocity dataset for analysis of alpine glaciers in High Mountain Asia
Authors: Marshall Emma , Rupper Summer , Forster Rick
Published: February 2023

Glaciers in high mountain Asia (HMA) are important seasonal water resources and potential geo-hazards to over 500 million people living throughout the Indian subcontinent. Understanding the trajectories of these glaciers in a warming climate is critical to the development of climate change adaptation and mitigation strategies. Glacier surface velocities represent a critical metric in this endeavor: they convey information about glacier dynamics and the overall ‘health’ of a glacier, and developments in satellite remote sensing capabilities and post-processing algorithms have made available large ice surface velocity datasets with global coverage, dense temporal resolution, and data-contributions from multiple satellite sensors. This work focuses on the Inter-Mission Time Series of Land Ice Velocity and Elevation (ITS_LIVE) dataset, a global, automated, multi-sensor ice velocity dataset, with the goal of evaluating its strengths and limitations for investigations of relatively small alpine glaciers in the HMA region. We explore methodological approaches for optimizing the study of these glaciers with the exciting but complex ITS_LIVE dataset. This work presents a comparison of different methodological approaches for working with ITS_LIVE data, preliminary results of seasonal surface velocity variability for several hundred glaciers across HMA, and comparisons between ITS_LIVE and other surface velocity products.
Forecasting the surficial displacements of a landslide triggered by snow melting basing on LSTM and image processing algorithms
Authors: Liu Yuting , Brezzi Lorenzo , Nava Lorenzo , Liang Zhipeng , Cola Simonetta
Published: February 2023

The majority of landslide-prone areas spread in mountainous areas with abundant rainfall. However, when high altitudes make areas prone to significant snowfall, the amount of such snowfall, as well as environmental temperature and humidity, should be taken into account to determine its effect on the condition of landslide stability. To pursue this aim, the present study focuses on the quantification of snow accumulation on the slope through approaches based on image analysis and on the prediction of surface displacements of the slope using a two-steps LSTM (Long short-term memory) algorithm. The main LSTM algorithm aims at forecasting the landslide displacement in the future 12 hours using as input the past 5 days data of rainfall, snowfall and movements of the slope, plus the weather prediction of the next day. The necessity of estimation of the trend of the snow condition makes it necessary to implement a secondary LSTM algorithm for estimating if the snow coverage is going to accumulate or melt in next 12 hours, again basing on the past 5 days environmental measurements (temperature and humidity) and a forecast of the future condition of the site. Both the algorithms are trained basing on the historical measurements of temperature, humidity, rainfall, snowfall and landslide displacement. The main code also includes a training based on the surficial movements of the slope measured by a topographical monitoring system. Within this model, the presence and the trend of the snow is evaluated by means of some image-processing algorithms aiming at evaluating the cover square percentage of white content in the RGB image, filtering out noises and false signals. The presented procedure is applied to the case of the Sant’Andrea landslide, located in Perarolo di Cadore (North Italy, Province of Belluno), whose bedrock is composed by dolomitic lithology and folded layers rich in anhydrides and gypsum easily erodible by water infiltration in the subsoil. The two-steps LSTM model implementation achieves the forecasting of the landslide displacements, focusing in particular on the effects of snow melting in the stability condition of the slope.
The Partitioning Processes of Sea Ice Associated Marine Ice Nucleation Particles Impacting the Arctic Clouds
Authors: Jensen Lasse , Kjærgaard Eva , Cifarelli Maria , Di Pompeo Rosella , D'Agostino Martina , Schmidt Jennie , Skønager Jane , Søgaard Dorte , Rosati Bernadette , Bilde Merete , Lund-Hansen Lars , Finster Kai , Šantl-Temkiv Tina
Published: February 2023

The Arctic is a region that is particularly vulnerable to the impacts of climate change, as it is warming at a faster rate than the rest of the world. This warming causes a decline in multiyear sea ice cover, which results in an increasing open-ocean surface with a much lower albedo therefore leading to positive feedback and enhanced warming. Another factor that plays a role in regulating the temperature in the Arctic is the type and extent of cloud cover. Aerosols that can serve as cloud condensation nuclei or ice nucleating particles (INPs) are key for cloud formation. Some microorganisms are known to produce INPs, but it is not well understood which microorganisms are responsible, which environments they inhabit, and how active they are. In this study, we set out to investigate the partitioning of INPs between the Arctic marine and atmospheric environment by combining in situ measurements with laboratory experiments.First, we wanted to determine if sea ice acts as a reservoir for INPs and, if so, whether the INPs are partitioned into the sea ice during its formation or produced by microorganisms within the sea ice. We used a modified ice-finger to grow sea ice using natural samples from West Greenland and found that INPs concentrate into the ice fraction during sea-ice formation, and that these INPs typically are associated with microorganisms.Next, we wanted to understand the temporal and spatial dynamics of INPs in Arctic sea ice. We collected sea ice cores from the Arctic before and during the spring sea ice phytoplankton bloom and analysed them using cold-stage INP measurements, flow-cytometry, and amplicon sequencing. The results showed that there are between <105 · L-1 (at the top) and >106 · L-1  (at the bottom of the sea ice) INP-10 present in the Arctic sea ice.  Finally, we wanted to determine the potential contribution of sea ice to the atmospheric INP pool in the Arctic. We introduced natural samples of bulk water and sea ice from Nuuk and Station Nord into a temperature-controlled sea spray simulation chamber and quantified the microorganisms and INPs present in the bulk water, surface microlayer and air before and after aerosolization. The results showed that the highly active INPs are efficiently aerosolized into the atmosphere during bubble-bursting where they may contribute to the formation of ice in clouds.Overall, this study provides new insight into the role of Arctic sea ice as a reservoir for INPs and the microorganisms that produce them, as well as the mechanisms by which INPs are released into the Arctic atmosphere. This information is important for understanding the impact of climate change on the Arctic region and the potential consequences for the rest of the world.
Revisiting the 1978 ML 5.2 Mt.Sokri earthquake, Korea
Authors: Kim Doyoung , Kim Kwang-Hee , Sohn Yu Jin , Lee Young-Cheol
Published: February 2023

The ML 5.2 earthquake occurred in Mt.Sokri (September 16, 1978), the center of South Korea. It was the fourth largest earthquake in South Korea since the modern seismic observation began. The Korea Meteorological Administration (KMA), the United States Geological Survey (USGS), and the International Seismological Centre (ISC) announced the location of the hypocenter respectively, but they were different. In this study, we analyzed the subsurface fault structure using current micro-earthquakes. We have used data collected by temporary seismic stations installed in the Mt.Sokri area by Pusan National University since May 2019 and the permanent seismic stations installed by KMA since 1978. KMA reported 188 earthquakes from 2007 to 2021 in the study area. We detected additional 280 micro-earthquakes using STA/LTA and template matching methods. The initial result of earthquake locations using HYPOELLIPSE was scattered across the study area. To obtain reliable locations, we relocated earthquakes using HypoDD. As a result, 468 earthquakes were relocated, about twice as many as those reported by KMA. We recognized earthquakes have occurred along WNW-ESE subsurface faults at the depth of 14 to 18km. We determined the focal mechanisms of 15 earthquakes with magnitudes greater than 2. The location of the Mt.Sokri earthquake was reviewed by comparing these results with the locations announced by the three institutions. Joint analysis of the focal mechanisms, distribution of earthquakes, and geological setting, the WNW-ESE plane was interpreted as the major fault plane. Apparently, the micro-seismicity locations in this study better correlated with the epicenter announced by USGS. However, it is difficult to confidently specify the location of the 1978 earthquake only to the current earthquakes.
Net greenhouse gas emission pathway for Finland based on fair share of allowed warming
Authors: Partanen Antti-Ilari , Palosuo Taru , Ekholm Tommi , Ollikainen Markku , Korhonen Hannele
Published: February 2023

Finland has set a legally binding goal of achieving “carbon neutrality” by 2035 and net-negative greenhouse gas emissions thereafter. The scientific background for this goal is based on an interpretation of what a nationally fair share of global carbon budget compatible with 1.5 °C warming is. This national carbon budget includes also non-CO2 greenhouse gas (GHG) emissions and is thus stricter than the original, global CO2-only carbon budget. Finland’s pathway to carbon neutrality relies not only on emission reductions but also on carbon sinks in the land use, land-use change and forestry (LULUCF) sector. The net sink in the LULUCF sector, as estimated in the national greenhouse gas inventory, is interpreted as negative emissions. This assumption is problematic, as part of the LULUCF sink is considered natural sink in the conceptual framework behind the global carbon budget estimates and assuming it entirely anthropogenic leads to underestimation of the net CO2 emissions.  

Here we present an analysis and revision of the Finnish net greenhouse gas emission pathway with two major improvements. First, we extend the carbon budget framework to nationally allowed warming to be able to account explicitly also for national non-CO2 GHG emissions. The global allowed warming until 2050 from future GHG emissions is calculated as the sum of the remaining warming to 1.5 °C, the global decreasing warming impact of past non-CO2 GHG emissions by 2050, and future warming due to reduced aerosols by 2050. We use the fair share used previously for allocating national carbon budget to calculate national allowed warming contribution until 2050 and subtract non-CO2 GHG contribution based on a Finnish carbon neutrality scenario and simulations with a simple climate model FaIR 2.1. The remaining allowed warming is then used to calculate the national CO2-only carbon budget. 

 The second improvement is to consider the recent advancements in disentangling natural and anthropogenic carbon fluxes in the LULUCF sector. National results from a recent global study indicate that the Finnish LULUCF sector has been a carbon sink due to the natural sink induced by CO2 fertilization and climate change. The large natural sink is expected to decrease especially in the most stringent global emission reduction scenarios.  

 The preliminary results indicate that Finland’s currently planned pathway is not compatible with its national fair share of allowed warming compatible with the 1.5-degree target, and more stringent emission reductions coupled with strengthening of the land sink and other forms of negative emissions are very likely needed.
Is plastic dust different from mineral dust? Results from idealized wind tunnel experiments.
Authors: Esders Eike , Sittl Sebastian , Krammel Inka , Babel Wolfgang , Papastavrou Georg , Babel Wolfgang
Published: February 2023

Atmospheric transport has been shown to effectively disperse microplasticparticulate matter to virtually every environment on the planet. Despite thisefficient long-range transport, only few studies have examined the fundamentalmechanisms of the atmospheric transport of microplastics. Here, we present theresults of wind tunnel experiments, examining the detachment behavior of plasticparticles ranging from 38 to 125 µm in diameter from flat substrates.Detachment was achieved solely by aerodynamic forces of the turbulent airflow.The detachment behavior of spheric microplastic particles (Polyethylene) andspheric glass microparticles (Borosilicate) of nominally the same diameter(63-75 µm) are contrasted across substrates with hydrophilic to hydrophobicsurface coatings. We further examine the effect of particle-particle collisions onthe detachment behavior of both Polyethylene and glass spheres. The criticalfriction velocity (u*,th), which is defined as the value at which 50% of allmicroparticles detach, ranged from 0.1 to 0.3 ms −1. Particle-particle collisionsreduced the u*,th of glass, but not that for PE. Results were compared withpredictions of a Jonhson-Kendall-Roberts model. The relation of diameter tou*,th compared well between results and prediction for Polyethylene spheres.Glass spheres were predicted to detach at smaller u*,th than polyethylenespheres, but detached at higher u*,th. Here, we argue that capillary forcesincreased the adhesion, which is not covered by the model. The combination ofparticle and substrate hydrophobicity influenced the relative humidity, at whichcapillary forces increased u*,th.