bluuebunny/crossref_metadata_2025 huggingface dataset:
A single band TIR-based algorithm to detect low-to-high thermal anomalies in volcanic regions
Authors: Aveni Simone , Laiolo Marco , Campus Adele , Massimetti Francesco , Coppola Diego
Published: March 2024

Volcanic eruptions pose a major threat to at least 800 million people. Studies revealed that ~50% of the ~1400 potentially active subaerial volcanoes still lack conventional ground-based monitoring networks. In this context, satellite data proves to be a cost-effective, yet reliable, information source for detecting early signs of volcanic activity and monitoring the evolution of eruptive events.Within the past two decades, several moderate resolution (~1 km) Mid-InfraRed (MIR) satellite-based volcano monitoring systems have been developed, mostly targeting high-temperature anomalies associated with eruptive activity. Subtle thermal anomalies, however, might occur from years to days prior major volcanic unrests and/or eruptions, and persist for a long time during the cooling stage of the erupted deposits.Studies revealed that Thermal InfraRed (TIR) bands, often characterised by higher spatial resolution (< 100 m) but lower revisit time (> 6 days), are well suited to detect subtle thermal anomalies. Yet, even in a high-temperature domain, TIR observations typically prove more effective in accurately determining the dimensions of active and cooling lava flows. Besides, high resolution TIR channels allow the retrieval of more detailed spatial information but with a temporal resolution inadequate for daily monitoring.Forefront TIR-equipped platforms, however, like the Visible Infrared Imaging Radiometer Suite (VIIRS), offer an unprecedented trade-off between spatial (375 m) and temporal resolution (up to 4 acquisitions of the same target per day), having the potential to provide accurate heat flux measurements before, during and after an eruption. Here we present a single-band TIR-based algorithm capable of detecting thermal anomalies in a broad range of volcanic settings, from crater lakes and localised low-temperature hydrothermal systems to high-temperature effusive events. The algorithm – based on temporal and contextual analyses to identify thermally anomalous pixels – can detect thermal anomalies for pixel-integrated temperatures as low as 0.5 K above the surrounding hot-spot-free background and as far as 25 km from the volcano’s summit while maintaining a false positive rate of ~2%.Results emerging from selected case studies envisage that the system will prove instrumental for detecting early signs of volcanic activity and for monitoring the evolution of thermal emissions, from unrest to eruption. Furthermore, the compilation of statistically robust multidecadal thermal datasets will provide novel insights and new perspectives into volcano monitoring, laying the ground for forthcoming higher-resolution TIR missions.
Quantifying key drivers of marine pyrite content and isotopic composition
Authors: Hemingway Jordon , Mertens Cornelia , Paradis Sarah
Published: March 2024

Microbial sulfate reduction (MSR) and subsequent pyrite burial in marine sediments plays a crucial role in Earth’s long-term carbon and oxygen budgets; by reducing sulfate and producing alkalinity, this process effectively increases atmospheric O2 and lowers CO2 levels. Given that MSR exhibits a large and reduction-rate-dependent sulfur-isotope fractionation, changes in pyrite sulfur-isotope compositions (δ34S values) through geologic time have long been interpreted to reflect global signals such as marine sulfate reduction rates, microbial community behavior, and the amount of sulfur buried as pyrite vs. evaporite minerals. However, recent research has demonstrated that marine MSR fractionation likely operates near an equilibrium limit regardless of reduction rate. These studies instead implicate local environmental and sedimentological factors as drivers of pyrite δ34S values. Despite this advancement, the sensitivity of pyrite formation rate and δ34S value to changes in environmental and sedimentological variables—both today and through geologic time—remains unconstrained due to the complex interactions between controlling variables.To provide mechanistic and quantitative constraints, we developed and applied a non-dimensional diagenetic model that extracts the natural variables governing pyrite formation. Assuming equilibrium MSR isotope fractionation and using only locally measured or globally interpolated boundary values as inputs (i.e., no free parameters), our model accurately predicts all available modern observations (n = 216 cores) with an average root-mean square error of 0.3 wt % for pyrite content and 16.5 ‰ for δ34S. Extrapolating this result, we estimate global pyrite burial flux to be ~1.3 × 1012 mol FeS2 yr−1 with a weighted-average δ34S value of ~-21 ‰ VCDT.This flux is statistically identical to independent estimates of total riverine sulfate input (i.e., pyrite-oxidation and evaporite-dissolution derived), indicating the sulfur cycle currently operates in steady state. However, calculated pyrite burial exceeds pyrite-oxidation derived inputs, suggesting net atmospheric O2 release and CO2 consumption by the sulfur cycle.Mechanistically, we conclude that pyrite formation rate is highly sensitive to local reactive iron input, whereas δ34S value is primarily controlled by organic carbon reactivity-to-sedimentation rate ratio (termed Da*, a modified Damköhler number) and organic carbon-to-sulfate ratio (termed Γ0). In contrast to previous models, we show that pyrite δ34S is largely insensitive to bioturbation due to counter-balancing impacts on Da* and Γ0. Rather, when combined with a geologic pyrite δ34S record, our interpretation requires an increase in Da* and decrease in Γ0 since the Paleozoic, possibly driven by changing organic matter reactivity and sulfate concentration through geologic time.
Seasonal variations in sediment transport from ice sheet terminus through a proglacial forefield. A case study from Leverett glacier, Western Kalaallit Nunaat (Greenland). 
Authors: Gevers Marjolein , Lane Stuart N. , Miesen Floreana , Mancini Davide , Jenkin Matthew , Bouscary Chloé , Perchanok Faye , Delaney Ian
Published: March 2024

Current climatic warming is causing accelerated melt of the Greenland Ice Sheet. Whilst the changing hydrological response is well known, the sediment export as well as the geomorphic changes in the proglacial area remain uncertain.  Here we present records of sediment transport from melt seasons 2022 and 2023 in the proglacial area of Leverett glacier, a land terminating glacier outlet on the Western part of the Greenland Ice Sheet. The proglacial area here is very well denifed by a waterfall cutting through bedrock functioning as terminal gauge, which allows for the installation of hydrological stations. These hydrological gauging stations, containing turbidity and pressure sensors, allow for estimation of discharge and suspended sediment concentrations over the melt season. Variations in bedload transport can be analysed using the sesimic data obtained from the geophones placed on the river bank close to the hydrological gauging stations. To convert the recorded seismic data into bedload flux, a Fluvial Inversion Model is used, which is calibrated using active seismics surveys and the water stage data from the hydrological gauging stations.The dataset allows us to investigate the relationships between bedload, suspended sediment, and water discharge from the Leverett glacier as well as sediment transport and deposition in the proglacial area. We observe several spring events in the first half of July, where suspended sediment concentration and water discharge increase simultaneously at the start of the melt season. During the first half of August, we observe a clear dilution signal, where increase in water discharge coincides with a decrease in suspended sediment concentration From insights about the relationship between water and sediment discharge from the ice sheet, we can speculate about the sediment export response to increased water discharge from the Ice Sheet.
Virtual Hydrological Laboratories to develop the next generation of conceptual models and support decision-making under change
Authors: Kavetski Dmitri , Thyer Mark , McInerney David , Gupta Hoshin , Westra Seth , Maier Holger , Jakeman Anthony , Croke Barry , Partington Daniel , Shanafield Margaret , Simmons Craig , Tague Christina
Published: March 2024

The ability of contemporary hydrological models to serve as a basis for credible prediction and decision making is increasingly challenged – especially as hydrological systems are pushed outside the envelope of historical experience. Conceptual models are the most common type of surface water hydrological model used for decision support due to reasonable performance in the absence of change, ease of use and computational speed that facilitate scenario, sensitivity and uncertainty analysis. Hence, conceptual models arguably represent the current "shopfront" of hydrological science as seen by practitioners. However, these models have notable limitations in their ability to resolve internal catchment processes and subsequently capture hydrological change. New thinking is needed to confront the challenges faced by the current generation of conceptual models in dealing with a changing environment. We argue that the next generation of conceptual models should combine the parsimony of conceptual models with our best available scientific understanding. We propose a strategy to develop such models using multiple hydrological lines of evidence. This strategy includes using appropriately selected physically-resolved models as "Virtual Hydrological Laboratories" to test and refine the simpler models' ability to predict future hydrological changes. This approach moves beyond the sole focus on "predictive skill" measured using metrics of historical performance, facilitating the development of the next generation of conceptual models with hydrological fidelity - i.e., that "get the right answers for the right reasons". This quest is more than a scientific curiosity – it is expected by environmental policy makers and broader stakeholders.
A view into the richness of processes in porous media
Authors: Guadagnini Alberto
Published: March 2024

Flow and transport scenarios taking place in porous media are characterized by a staggering range of physical, chemical, and biological processes. The dynamics associated with these are distributed across an astonishingly wide range of (spatial and temporal) scales, thus contributing to the challenges related to their observation and description. Direct observation and attempts to a quantitative characterization of these processes indicate that they are prone to multiple interpretations, as rendered through various conceptual and mathematical formulations and their parameterization. Even the outcomes of apparently straightforward models of flow (or chemical transport) can surprise us! As complexity related to the formulation and parametrization of processes and their feedbacks increases, so does the need to establish approaches enabling us to quantify the effect of various types of uncertainty on target quantities of interest. For example, tackling the often strong (spatial) heterogeneity of parameters embedded in a model and coping with our limited ability to describe all of the relevant details of the porous medium hosting processes of interest poses significant challenges. In this broad context, I will initiate a discussion about uncertainties related to process formulation and parametrization and the way they can propagate to model outputs such as, e.g., water availability, solute concentrations, source protection regions, or reaction rates. The discussion is set in a framework encompassing experimental studies, characterization of porous media heterogeneity, sensitivity analysis for model diagnosis, and stochastic inverse modeling. Sensitivity analyses approaches are tackled with a focus on their ability to identify the relative importance of processes (and associated parameters) embedded in a model and driving system behavior. The ensuing results are then employed to inform model calibration under uncertainty. All of these aspects are exemplified through the analysis of settings related to three distinct scales. These comprise a regional scale complex aquifer system subject to diverse forcings, a laboratory scale scenario involving dynamics of pharmaceuticals in a porous medium, and direct observations of processes acting at nanoscales and governing material fluxes associated with chemical weathering related to rock dissolution. While these systems are associated with very different scales (and processes), their analysis is unified through the use of stochastic approaches sharing common traits and leading to similar workflows for uncertainty quantification.
Effects of Niño1+2 and Niño3.4 ENSO Events over Euro-Mediterranean Climate Variability 
Authors: Yavuzsoy-Keven Ece , Ezber Yasemin , Sen Omer Lutfi
Published: March 2024

El Niño Southern Oscillation (ENSO) is a climate phenomenon that affects the atmospheric circulation of the Northern Hemisphere and causes short-term variability in temperature and precipitation patterns. ENSO impacts over the Euro-Mediterranean (EM) region are commonly defined by using Niño3.4 and Niño3 indices. However, some recent studies indicate that the ENSO event represented by both Niño1+2 and Niño3.4 indices (shared ENSO) is more effective over EM region climate.In this study, we examine the response of the EM climate to ENSO events detected by Niño1+2 and Niño3.4 regions. NCEP/NCAR Reanalysis surface air temperature, precipitation, 500 hPa geopotential height, 850 hPa wind, and 300 hPa zonal wind datasets and SST-based ENSO indices from ERSSTv4 were used in the analysis for boreal winters between 1950 and 2019. For composite analysis, we separated ENSO events as El Niño and La Niña according to those observed in Niño1+2, Niño3.4, and both regions. We also tried to understand if there is any relation between ENSO and teleconnection patterns such as NAO, East Atlantic (EA), Trough Displacement Index for the Mediterranean Trough (TDI_MedT), and East Atlantic/Western Russia (EAWR) by using the cross-correlation analysis. Additionally, investigate the winter (December, January, February, DJF) ENSO’s possible lagged impacts on the teleconnection patterns in the subsequent seasons, spring (March-April-May, MAM), summer (June-July-August, JJA), and autumn (September-October-November, SON).The major finding of this study is that the shared ENSO event is more effective over the EM climate than the ENSO events detected only by Niño1+2 or Niño3.4 indices. Further, it is also important for the predictability of the EM climate. In the shared El Niño event, the Middle East and much of North Africa tend to become colder than climatology while Europe becomes warmer. The anticyclonic wind anomaly over western Europe causes drier air in southern Europe and wetter air in northern Europe. The shared El Niño event also modulates the westerly flows at the upper troposphere. The westerly flow accelerates over high latitudes while decelerates over European mid-latitudes, causing northern Europe to be wetter and the Mediterranean Basin to be drier. The cross-correlation analysis including all SST-based ENSO indices and teleconnection indices that the EA index has a significant correlation with the Niño1+2 index across all seasons.
Understanding strain partitioning, segmentation, and the slip-rate history of the Middle Branch of the Northern Anatolian fault, Turkey
Authors: Harrichhausen Nicolas , de Sigoyer Julia , Klinger Yann , Yildirim Cengiz , Karakaş Melike , Camus Baptiste
Published: March 2024

We present preliminary results from a paleoseismic study of the middle branch of the Northern Anatolian Fault (MNAF) in Turkey. Despite low instrumental seismicity and geodetic slip rates (~2.5 mm/yr) relative to the northern branch, historical, archeological, and paleoseismic studies indicate the MNAF has hosted several damaging earthquakes in the last two millennia. Recent geomorphic and bathymetric analyses reveal segmentation of the MNAF that may indicate strain partitioning of normal and strike slip along parallel fault strands. However, it remains uncertain whether these fault segments have ruptured simultaneously. Geologic studies have constrained right-lateral slip rates to between 2 and 5.3 mm/yr, with most results contrasting against the present-day geodetic slip rate of ~2.5 mm/yr. Whether this represents a reduction in strain rate along this branch of the Northern Anatolian fault is not clear. Our study has two main objectives: first, to delineate the earthquake history along the newly identified segment of the MNAF beneath Lake Iznik and map its onshore extensions to the east and west of the lake; second, to determine the right-lateral slip rate of the MNAF across different temporal scales. We will present preliminary results from geomorphic mapping, electromagnetic conductivity and ground penetrating radar surveys, and paleoseismic trenching aimed at achieving these objectives. By further establishing the earthquake history and length of the new branch beneath Lake Iznik, we aim to ascertain whether this segment has ruptured concurrently with parallel and along-strike segments, allowing us to estimate paleo-earthquake magnitudes and maximum rupture lengths. Concurrently, by constraining the slip rate of the MNAF over time, we seek to understand whether slip along this branch has decreased and if this reduction is linked to a subsequent increase in slip rate on either the northern or southern branch of the Northern Anatolian Fault.
Climate risk analysis for adaptation planning in Zambia’s agricultural sector
Authors: Laudien Rahel , Chemura Abel , Cronauer Carla , Heckmann Tim , Gleixner Stephanie , Gornott Christoph , Murken Lisa , Tomalka Julia
Published: March 2024

Climate change and climate extremes increasingly threaten agricultural production and thereby pose a serious risk to agricultural livelihoods, particularly in the Global South. In support of adaptation planning, science-based information on projected climate impacts and sound information on the suitability of adaptation options is needed.This study provides a comprehensive analysis of current and future climate-related risks in Zambia – a country that is highly vulnerable to climate change due to its geographic location and the strong socio-economic dependency on agriculture. Using data from ten Global Climate Models (GCMs) under two climate change scenarios (SSP1-RCP2.6 and SSP3-RCP7.0), we analyze future trends in climatic conditions and model their impacts on agricultural yields and crop suitability. Moreover, the study evaluates two adaptation options to promote climate-resilience in the agricultural system i.e. 1) conservation agriculture and 2) a climate and agricultural extension service called PICSA (Participatory Integrated Climate Services for Agriculture). The evaluation includes biophysical, economic, financial and gender aspects to provide comprehensive and usable information that can inform adaptation policies on the ground. The study was co-designed together with stakeholders from Zambian governmental institutions, civil society, academia, the private sector, practitioners and development partners.Results show the strongest negative impacts of climate change in South Western Zambia where the strongest increases in temperature and dry conditions are projected. The projected impacts underline the need for strong adaptation efforts: 1) Conservation agriculture can buffer climate impacts in the near term and even increase sorghum yields by 25 to 31% in drought-prone areas in Zambia. It can play a vital role in adapting to increasingly extreme and dry climatic conditions. 2) The PICSA approach proved to be a highly economically beneficial adaptation option with each USD invested generating between 3.6 and 3.8 USD in benefits.In addition, the study reflects on lessons learned from interdisciplinary and stakeholder-driven research – focusing not only on the Zambian context, but also on climate risk analyses that were conducted in Burkina Faso, Cameroon, Ethiopia, Ghana, Madagascar, Niger and Uganda.
Disentangling projected stationary wave changes: implications for future drying of the Mediterranean region
Authors: Keller Benny , Garfinkel Chaim
Published: March 2024

An intermediate-complexity moist general circulation model is used to disentangle changes in the large-scale zonally asymmetric circulation due to rising GHGs. We run multiple idealized experiments in order to isolate, and subsequently synthesize, the physical processes driving these changes. In particular, we examine stationary wave changes forced by land–sea contrast, horizontal heat fluxes in the ocean, and orography, in response to a quadrupling of CO2 concentrations. A particular focus is on the anomalous ridge in the Mediterranean region associated with the decline in precipitation in this heavily populated region.  Our results suggest a combination of two mechanisms is responsible for future Mediterranean drying. The first is a global phenomena, a lengthening of intermediate-scale stationary waves due to strengthening of subtropical upper-tropospheric zonal mean zonal winds, shown previously to account for hydroclimatic changes in the western US. We find this mechanism to be dominated by change in waves forced by ocean horizontal heat fluxes. The second mechanism is a regional one, a strengthening of large-scale stationary wave modes over Europe and the north Atlantic, dominated by changes in stationary waves forced by land-sea contrast. This second mechanism is strongly tied to an altered temperature gradient between the North Atlantic and Europe, in response to rising GHGs. Our work demonstrates how large-scale upper-tropospheric circulation changes are directly tied to regional hydroclimate.
The Atlantic Multi-decadal Variability in observations and in a large historical multi-model ensemble: Forced and internal variability
Authors: Christiansen Bo , Yang Shuting , Drews Annika
Published: March 2024

There is an ongoing discussion about the contributions from forced and natural sources to the Atlantic Multi-decadal Variability (AMV).  As the AMV influences the general climate in large regions, this question has important consequences for climate predictions on decadal timescales and for a robust estimation of the influence of climate forcings. Here, we investigate the Atlantic Multi-decadal Variability (AMV) in observations and in a large CMIP6 historical climate model ensemble. We compare three different definitions of the AMV aimed at extracting the variability intrinsic to the Atlantic region. These definitions are based on removing from the Atlantic temperature the non-linear trend, the part congruent to the global average, or the part congruent to the multi-model ensemble mean of the global average. The considered AMV definitions agree on the well-known low-frequency oscillatory variability in observations, but show larger differences for the models. In general, large differences between ensemble members are found. We estimate the forced response in the AMV as the mean of the large multi-model ensemble.  The forced response resembles the observed low-frequency oscillatory variability for the detrended AMV definition, but this definition is also the most inefficient in removing the forced global mean signal. The forced response is very weak for the other definitions and only few of their individual ensemble members show oscillatory variability and, if they do, not with the observed phase. The observed spatial temperature pattern related to the AMV is well captured for all three AMV definitions, but with some differences in the spatial extent. The observed instantaneous connection between NAO and AMV is well represented in the models for all AMV definitions. Only non-significant evidence of NAO leading the AMV on decadal timescales is found.
Τοwards a unified mοdelling οf wave-current-turbulence interactiοns in three dimensiοns: applicatiοn tο Alderney Race (France) and Gregοry Sound (Ιreland) 
Authors: Calo Lorena Gil , Bennis Anne-Claire , Boutet Martial , Dias Frederic
Published: March 2024

As tidal turbines are to be implemented in the highly energetic sea of Alderney Race (France), the aim of the study is to define a way to simulate its turbulent water regime and that of the similar site of Gregory sound (Ireland), in interaction with the ocean waves.  

The goal is to include a compatible 3D turbulence model in the existing formulations to develop a unified model for wave-current-turbulence interactions that is realistic in terms of numerical resources. This will be achieved by integrating the original LES turbulence model of Leray-α to sets of equations modeling wave-current interactions in 3D. 

This is being done using the CROCO numerical modeling system (https://www.croco-ocean.org) applied to the coastal ocean, in which the algorithms for the turbulence filtering procedures are to be implemented. The conclusions until now are the following: i) the Leray-α filtering procedure gives accurate results when applied for the three-dimensional mixing, ii) the Leray-α filtering procedure re-energizes the flow, iii) the model allows the coarser resolution to simulate the finer one, with a relevant reduction of the computational costs.  

For the next steps, Leray-α will be used to simulate the real locations of Alderney Race and Gregory sound, and waves interactions will be included in the study through the coupling of CROCO with the model Wavewatch III. 
Explainable AI for distinguishing future climate change scenarios
Authors: Labe Zachary , Delworth Thomas , Johnson Nathaniel , Cooke William
Published: March 2024

To account for uncertainties in future projections associated with the level of greenhouse gas emissions, most climate models are run using different forcing scenarios, like the Shared Socioeconomic Pathways (SSPs). Although it is possible to compare real-world greenhouse gas concentrations with these hypothetical scenarios, it is less clear how to determine whether observed patterns of weather and climate anomalies align with individual scenarios, especially at the interannual timescale. As a result, this study designs a data-driven approach utilizing artificial neural networks (ANNs) that learn to classify global maps of annual-mean temperature or precipitation with a matching emission scenario using a high-resolution, single model initial-condition large ensemble. Here we construct our ANN framework to consider whether a climate map is from SSP1-1.9, SSP2-4.5, SSP5-8.5, a historical forcing scenario, or a natural forcing scenario using the Seamless System for Prediction and EArth System Research (SPEAR) by the NOAA Geophysical Fluid Dynamics Laboratory. A local attribution technique from explainable AI is then applied to identify the most relevant temperature and precipitation patterns used for each ANN prediction. The explainability results reveal that some of the most important geographic regions for distinguishing each climate scenario include anomalies over the subpolar North Atlantic, Central Africa, and East Asia. Lastly, we evaluate data from two overshoot simulations that begin in either 2031 or 2040, which are a set of future simulations that were excluded from the ANN training process. For the rapid mitigation experiment that starts a decade earlier, we find that the ANN links its climate maps to the lowest emission scenario by the end of the 21st century (SSP1-1.9) in comparison to the more moderate scenario (SSP2-4.5) that is selected for the later mitigation experiment. Overall, this framework suggests that explainable machine learning could provide one possible strategy for assessing observations with future climate change pathways.
Investigating herbicide transport and fate in vegetated lysimeters with numerical modeling and stable carbon isotopes
Authors: Rein Arno , Imig Anne , Augustin Lea , Groh Jannis , Pütz Thomas , Elsner Martin , Einsiedl Florian
Published: March 2024

The application of pesticides can induce severe impacts to the vadose zone, groundwater, and their ecosystems. A study was carried out on two lysimeters located in Wielenbach, Germany. Different soil textures were considered within the soil cores, consisting of sandy gravel and clayey sandy silt. The lysimeters were vegetated with maize, and four different herbicides were applied according to common agricultural practice. Over a period of 4.5 years, concentrations of the herbicides and selected metabolites were monitored in the lysimeter drainage. In addition, stable carbon isotopes (δ13C) were analyzed for investigating biodegradation influences of two of the applied herbicides.In a first step, we characterized unsaturated flow in the lysimeters based on stable water isotope measurements (δ2H and δ18O) combined with modeling. Different setups within the numerical model HYDRUS-1D were compared, including single and dual porosity approaches. Then, the unsaturated flow models were extended for describing reactive transport of the herbicides, and simulations were interpreted in combination with measured δ13C values. At the end of the observations, 0.9 to 15.9% of the applied herbicides (up to 20.9% for herbicides plus metabolites) were recovered in lysimeter drainage. Some metabolites were observed to accumulate in drainage, and biodegradation was indicated by small isotopic shifts in δ13C to less negative values in the leached herbicides. In the later sampling campaign (7.5 months after herbicide application), a higher increase in δ13C (less negative values) compared to earlier sampling (19 days after application) points towards stronger biodegradation. This can be explained by a higher biodegradation potential when the infiltrated water and the herbicides were affected by longer mean transit times in the unsaturated zone.Observations were reproduced by modeling, where the overall dynamics of herbicide concentration in the lysimeter drainage could be covered well by the model setups. The concentration peaks were partly associated with heavy precipitation, which in turn indicates that the transport was influenced by preferential flow. Limitations were found for describing preferential flow events by using single and dual porosity models, as some concentration peaks were over- or underestimated. The use of δ13C for compound-specific isotope analysis allowed obtaining some evidence on biodegradation of the two herbicides in the unsaturated zone, which was also validated with the model results. 
Illuminating the Interplay between Clouds, Aerosols, and Radiation: Introducing the ESA EarthCARE L2 processing chain.
Authors: van Zadelhoff Gerd-Jan , Donovan David ,   CARDINAL team
Published: March 2024

The interactions between clouds, aerosols, and solar and terrestrial radiation play  key roles in the Earth’s Climate. Despite a long history of satellite observations, further high-quality novel observations are needed for atmospheric model evaluation and process studies. It has been recognized that true height-resolved global observations of cloud and aerosol properties are essential for making progress. EarthCARE is an upcoming ESA/JAXA mission scheduled to fly in 2024, focusing on providing these observations.Operating in a sun-synchronous orbit at 393 km altitude with a descending node at 14:00, EarthCARE's payload comprises two innovative active (Atmospheric UV High spectral resolution Lidar - ATLID and Cloud Profiling Doppler Radar - CPR provided by Japan) and two passive (Multi-Spectral Imager - MSI and Broad-Band Radiometer - BBR) instruments. Using these instruments, EarthCARE will provide global profiles of clouds, aerosols, and precipitation properties, along with co-located radiative TOA flux measurements. These atmospheric microphysical properties and associated radiative fluxes will be used to evaluate the representation of aerosols, clouds, and precipitation in weather forecast and climate models, contributing to the improvement of parameterization schemes. The ESA scientific retrieval processors fully exploit the synergy of these observations. EarthCARE will provide twenty-five science (Level 2) products. These products include nadir profiles of cloud, aerosol and precipitation properties along with constructed three-dimensional cloud-aerosol-precipitation domains and associated derived radiative properties, such as heating rates. The final L2 processor compares the forward modeled top-of-atmosphere broad-band radiances and fluxes based on the constructed 3D atmospheric scenes with those measured by the BBR in order to assess and improve the quantitative understanding of the role of clouds and aerosols in the Earth's radiation budget.This presentation will provide an overview of the EarthCARE mission, its data processors and scientific products.
The double phase curve of TRAPPIST-1b and c at 15 microns
Authors: Gillon Michael ,   JWST Program 3077 team
Published: March 2024

Small rocky planets are now known to be very frequent in temperate orbits around low-mass M-dwarfs. The most pressing question regarding these ubiquitous planets concerns their capacity to maintain significant secondary atmospheres despite the adverse environment (high XUV fluxes, winds) and history (long pre-main-sequence) brought by their small host stars. Here, we present the photometric observation by JWST/MIRI of the combined thermal phase curve of the two inner planets of the TRAPPIST-1 system (Cycle 2 program 3077). These observations aimed to determine if the two planets are bare rocks or not by complementing the Cycle 1 measurements of their daysides' thermal emission at 15 microns (for b and c) and 12.8 microns (for b).
Carbon and sulfur trapping during contact metamorphism: Impact on volatile transfers in sedimentary basins with magmatic activity, example of the Guaymas Basin.
Authors: Cheviet Alban , Buatier Martine , Choulet Flavien , Goncalves Philippe , Galerne Christophe , Riboulleau Armelle , Bach Wolfgang , Vennemann Torsten
Published: March 2024

The opening of sedimentary basins is often accompanied by magmatic activity, and the emplacement of magmatic sills in the sediments. Contact metamorphism at the edges of the sills releases  large amounts of volatiles (H2O, CO2, CH4, and H2S), disrupting the carbon and sulfur cycle within the basin. The volatiles then migrate toward the seafloor and may be released into the oceans and atmosphere. While the reactions of dehydration, decarbonation, and desulfurization during contact metamorphism are well understood, the interactions between the produced fluids and the rocks remain unclear, especially when the fluids remain trapped within the metamorphic aureoles. This study, based on samples collected during the IODP Expedition 385 in the Guaymas Basin, aims to quantify the fluids produced and trapped in the metasediments during the emplacement of magmatic sills. Geochemical and mineralogical characterization of sediments in contact with the sill indicates metamorphic reactions, primarily affecting silica polymorphs (opal-A and opal-CT), diagenetic sulfides (pyrite), and detrital minerals (mainly quartz, clays, and feldspars), and cracking of the organic matter. The transitions from opal-CT to metamorphic quartz and from pyrite to pyrrhotite are good markers of the metamorphic aureoles. The size and the mineralogical assemblages differ in the upper and the lower aureoles suggesting major fluid rock interactions below the sill.  Indeed in this metamorphic aureole, the precipitation of carbonate-pyroxene-pyrrhotite patches within a quartz-plagioclase matrix is a good indicator of fluid-rock interactions at about 200-400°C. These newly formed carbonate patches indicate the trapping of metamorphic fluids below the sill. Isotopic data (δ18O and δ13C) were used to estimate the peak temperature of metamorphism and precipitation of carbonates. Additionally, thermodynamic modeling was conducted to understand the conditions of these reactional textures in the metasediments below the sill and quantify the amount of carbon and sulfur trapped under the sill. We show that a third of the carbon released to the fluid by organic matter cracking is directly trapped under the sill as carbonates. These results indicate that a significant fraction of the carbon initially released upon emplacement of the sill is sequestered deeply and doesn't rise up to the ocean floor.
High-resolution satellite measurements of NO2 and CO2 in power plant plumes
Authors: Wagner Thomas , Beirle Steffen , Borger Christian
Published: March 2024

The Environmental Mapping and Analysis Program (EnMAP) satellite is a hyperspectral satellite instrument for the monitoring of terrestrial and aquatic ecosystems. It provides high spatial resolution (30 x 30 m²) but relatively low spectral resolution (~6.5 nm FWHM in the visible to near-infrared spectral range and ~10 nm FWHM in the shortwave IR spectral range). Although the spectral information of ENMAP observations is limited, it is possible to analyse the atmospheric NO2 and CO2 contents from ENMAP spectra for strong emission plumes using differential optical absorption spectroscopy. While the CO2 signal is close to the detection limit, the evolution of the downward NO2 plumes from power plants can be well quantified.We present the spectral analyses of both trace gases and show measurement results for power plant plumes from Riyadh in Saudi Arabia and the Highveld in South Africa. We compare the ENMAP NO2 results to observations from the TROPOMI satellite instrument and aircraft measurements. Our results show that ENMAP NO2 and CO2 measurements can be used to study the chemical and dynamical evolution of power plant plumes. For example, the conversion of NO to NO2 can be quantified, or turbulence elements of the plumes can be clearly identified. The simultaneous observation of NO2 and CO2 might also allow the characterization of different power plants by their emission ratio. Due to the high spatial resolution of ENMAP also plumes from nearby power plants with distances of only a few hundred meters can be separated. 
Microphysical cloud properties in the initial phase of Arctic cold air outbreaks
Authors: Klingebiel Marcus , Jäkel Evelyn , Schäfer Michael , Ehrlich André , Wendisch Manfred
Published: March 2024

Cloud streets are a common feature of cold air outbreaks in the Arctic region. These are long, parallel bands of cumulus clouds that form perpendicular to the wind direction. They are caused by the interaction between the cold air mass and the warm ocean surface. Within the framework of (AC)³, the HALO-(AC)³ campaign was performed in spring 2022 involving several research aircraft to study cold air outbreaks and their belonging cloud streets. In this study we use a spectral imaging instrument, called AISA Hawk, to retrieve cloud microphysical properties in the very initial phase of these cloud streets and therefore focus on their development over the leads in the marginal sea ice zone. 
Contrasting variations of chemical weathering processes during the initial ablation period in two different glacial drainage systems, Tibetan Plateau
Authors: Yu Zhengliang
Published: March 2024

Subglacial drainage system plays a central role in regulating chemical weathering processes in glacier environments. However, the influence of glacial drainage systems’ seasonal evolution on chemical weathering processes and consequent carbon sink effect is still unclear. This study selected the Parlung No. 4 Glacier in the southeast Tibetan Plateau (TP) and Kuoqionggangri Glacier in the central TP as the study areas, representing the typical temperate glacier and polar glacier, respectively. Sampling campaigns were conducted during the initial ablation period of those two glaciers when glacial drainage systems may undergo significant transformation. River water samples were collected almost daily for glacial runoff and 5-day intervals for outlets of the catchments. Evidences from tracer tests and Ca2+*/SiO2* show that glacial drainage system of the Kuoqionggangri Glacier is quite constant and it is dominated by a supraglacial pattern (* represents ionic concentration after atmospheric inputs correction). Subglacial drainage system of the Parlung No.4 glacier, however, transferred from a supraglacial pattern during the early monsoon season to a channelized pattern after June 25th. Cationic budget and major anionic sources discrimination (HCO3-) show that chemical weathering processes in the polar glacial catchment (Kuoqiongqu) has been displaying minor temporal change even though water discharge experienced a 7 times increment. Nevertheless, carbonate dissolution in the temperate glacial catchment (Rinongqu) was 24% decreased but sulfide oxidation 23% increased with the elapse of monsoon season. Its DIC (equivalent to HCO3-) sources from biological CO2 are 10% higher in early (before May 21st) and late monitoring periods (June 26th to July 10th) while the input proportion of atmospheric CO2 shows an opposite temporal change with 12% higher proportion from May 22nd to June 25th. The seasonal change of net CO2 consumption rate caused by chemical weathering (ФCO2_net) in the Kuoqiongqu catchment is positive correlated with water discharge, indicating carbon sink effect in the polar glacial catchments of the central TP is mainly governed by water discharge. ФCO2_net in the early subglacial channels reopen period is even slightly lower than that from April 2nd to May 10th when water discharge is more than 2.4 times lower because of dramatic increases in CO2 release rate caused by sulfuric acid dissolve carbonate (ФCO2_sul). This study highlights the evolution of glacial drainage system exerted crucial effects on carbon cycle by regulating chemical weathering processes.
Radiocarbon isotopic disequilibrium shows little incorporation of carbon in soils and fast cycling in a boreal forest ecosystem
Authors: Tangarife-Escobar Andres , Guggenberger Georg , Feng Xiaojuan , Muñoz Estefania , Chanca Ingrid , Peichl Matthias , Smith Paul , Sierra Carlos
Published: March 2024

Boreal forests, as critical components of the global carbon (C) cycle, fix annually substantial amounts of atmospheric C. However, the timescales at which this C is cycled through the various ecosystem compartments are yet not well understood. To elucidate the temporal dynamics between photosynthesis, allocation and respiration of C, we assessed the radiocarbon (14C) to understand the fate of C in a boreal forest ecosystem. Samples from a boreal forest stand at the ICOS station Svartberget (SVB) in northern Sweden were collected, including vegetation, soil cores, atmospheric CO2 and the 14CO2 values from incubated topsoil were used to interpret D in different ecosystem pools. Additionally, we conducted comprehensive analyses of Δ14CO2 released from forest floor soil respiration (FFSR) over a 24-hour cycle and calculated the Δ14C signature of the total ecosystem respiration following the Miller-Tans approach. We show that vegetation pools presented a positive D indicated by the enrichment with bomb 14C (produced mostly between 1950 and 1964), suggesting a fast-cycling rate (in the order of months to years) for living biomass and intermediate for dead biomass (years to decades). In contrast, soils showed a negative D, indicating minimal incorporation of bomb 14C. FFSR showed diurnal Δ14C variability with an average value close to the atmosphere (-2.33‰ in summer 2022 at SVB), suggesting that the output flux is dominated by autotrophic respiration of recently fixed and post-bomb labile C. Calculations for Δ14C in ecosystem respiration (166 ± 66.2‰), which is enriched in comparison to FFSR, in ecosystem respiration. Although the boreal forest stores significant amounts of C in the soil, , where it is cycled relatively fast. Only minimal amounts of recent C are incorporated and stabilised over long time scales. The potential of the boreal forest to mitigate climate change has to be further studied emphasizing the critical role of soil organic carbon persistence, where the ecosystem-atmosphere 14C disequilibrium may provide powerful insights.
PASSIVE SAMPLING OF POLYCHLORINATED BIPHENYLS (PCB) IN POLLUTED KARST GROUNDWATER; Study case: Krupa, Slovenia 
Authors: Koroša Anja , Mali Nina , Auersperger Primož
Published: March 2024

Polychlorinated biphenyls (PCBs) are synthetic organic compounds (209 possible isomers) of high physical, chemical and biological stability, and persist for long periods in a contaminated environment: they are undegradable (Hutzinger et al., 1974). They are biotoxically active compounds, and in animals and people cause acute and chronic damage to the skin, liver and lungs. In addition they cause metabolic disorders and disturbances to the action of the endocrine system, and are associated with loss of bodyweight and immuno-sensitivity. They are mutagenic and teratogenic, and are suspected to be carcinogenic (Safe, 1984). In Slovenia was an increase in use of PCBs after 1960. Between 1962 and 1983, a capacitor manufacturer disposed of PCB contaminated oil in the karstic region of Bela Krajina where it contaminated the spring of the Krupa River. The PCB pollution problems in karstic area of Krupa River are related to sinking surficial streams that mix with the regional groundwater supply, thus endangering the quality of the groundwater reservoirs. The PCB pollution of the Krupa River drew the public’s attention to the chemical burden of Slovenians, and the demand for studies has been rising since. This study presents the application of the passive sampling technique for monitoring PCBs within the Krupa spring. Monitoring programmes for groundwater are largely based on the collection of grab (spot) samples. One of the methods used for such studies can also be passive sampling. Contrary to grab sampling, passive sampling is less sensitive to accidental extreme variations of the organic pollutant concentration in natural waters and it also allows for a large range of contaminants to be detected at once. A passive sampler can cover a long sampling period, integrating the pollutant concentration over time. Passive samples were analyzed by gas chromatography mass spectrometry (GC-MS). For the interpretation of chromatograms, the AMDIS deconvolution was used. The deconvolution was covered by the GC-MS library with retention times for 921 organic contaminants from Agilent USA, as well as by the NIST 2008 library of mass spectra.The legacy of the PCB pollution of the Krupa River in Bela krajina is still measurable and passive sampling with active carbon fibres was proved to be an appropriate method for monitoring PCB pollutants in groundwater.