bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Mass Balance of the Cordillera Darwin Icefield, Tierra del Fuego, Chile
Authors: Temme Franziska , Sommer Christian , Fürst Johannes J.
Published: March 2024

The Cordillera Darwin Icefield (CDI) in Tierra del Fuego is the third-largest temperate icefield in the southern hemisphere, covering an area of 2606 km2 and storing at least twice the ice volume of the European Alps. More than half of the CDI glaciers are in direct contact with proglacial lakes or fjords, making them susceptible to both climatic surface mass change and ice-dynamic adjustments. Remote sensing studies have observed important mass losses in the region over the last decades. Despite the overall glacier retreat, individual glaciers show contrasting behavior, with some maintaining stable conditions or even thickening and advances, particularly in the central and southern part of the CDI. Associating the recent developments with atmospheric changes is challenging as in-situ observations of climatic conditions and glacier mass balance are scarce due to the harsh weather conditions and the difficult accessibility of the area.We aim for generating a first, high-resolution simulation of surface mass balance for the entire CDI over the last two decades (2000-2022). Comprising all mass gain and loss terms at the surface, the surface mass balance is ultimately tied to robust high-resolution information on the atmospheric conditions. We will employ state-of-the-art statistical downscaling of atmospheric variables, paying special attention to downscaling of precipitation and the orographic effects over the high relief terrain. Moreover, climate conditions in Southern Patagonia are characterized by strong, year-round westerly winds, leading to efficient snow drift and increased spatially heterogeneity of snow deposition.The results of our study will enable us to analyze variations in surface mass balance across space and time in the CDI. The key objective is to reliably disentangle the climatic imprint on glacier mass loss in the Cordillera Darwin for the last two decades. This climatic attribution is unprecedented and a unique opportunity to study the effects of climate variability and change in the higher mid latitudes of the southern hemisphere. Mass budgeting with remotely sensed mass balance observations will finally allow to derive a first estimate of frontal ablation and thus ice-dynamic controls on glacier changes in the CDI.
Frost damage in unsaturated porous media
Authors: Le Dizes Castell Romane , Sinaasappel Rosa , Fontaine Clémence , Smith Scott , Kolpakov Paul , Bonn Daniel , Shahidzadeh Noushine
Published: March 2024

Frost damage in porous materials is a weathering mechanism that can cause dangerous rockfalls or damage to built cultural heritage. The volume expansion of 9% when water freezes can be one of the cause of frost damage. This does not, however, explain why partially saturated porous stones also show damage despite the fact that ice should have room to grow. By performing experiments both at the scale of a single pore and in a real stone, we investigate the mechanism of frost damage at low water saturations at the pore scale and how it relates to macroscopic damage. We observe that the meniscus at an air-water interface confines the water in the pores. Because of this confinement, ice that forms will exert a pressure on the pore walls rather than growing into the pore. The amplitude of stress is found to be larger in small pores and when the meniscus has a larger contact angle with the walls. The contact angle is also observed to increase in the case of multiple freeze-thaw cycles, which increases the likelihood of damage. We find that cracks start first in the ice (being weaker than the confining material), followed by damage in the material itself. Remarkably, when multiple air-water interfaces are induced within limestone samples through a hydrophobic surface treatment, the stones are much more susceptible to frost damage than are uncoated stones, with cracks appearing preferentially at the hydrophilic-hydrophobic interface. This shows that indeed the meniscus confining the water during freezing and consequently the wetting properties are the relevant factors for frost damage in partially saturated porous stonesReference: R. Le Dizès Castell, R. Sinaasappel, C. Fontaine, S. H. Smith, P. Kolpakov, D. Bonn, and N. Shahidzadeh, “Frost Damage in UnsaturatedPorous Media,” Physical Review Applied, vol. 20, p. 034025, Sept. 2023.
Anthropogenic factors, not hydrometeorology, explains plastic pollution variability in the Odaw river 
Authors: Pinto Rose , van Emmerik Tim , Duah Kwame , van der Ploeg Martine , Uijlenhoet Remko
Published: March 2024

Variations in macroplastic transport are often linked to hydrometeorological conditions (wind, precipitation, and discharge). However, due to the predominant focus on these hydrometeorological factors as the main driving forces, most research overlooks the impact of anthropogenic factors, such as mismanaged plastic waste (MPW) on plastic transport variability. Here, we investigate the roles of both hydrometeorological and anthropogenic factors on plastic pollution. We collected field data on floating, riverbank, and land litter (macroplastics) between December 2021 to December 2022 at 10 bridge locations along the Odaw river. We tested seasonality in plastic transport/density with the Mann-Whitney U-test. Furthermore, we used multiple regression analysis to evaluate the combined effect of all the hydrometeorological variables (rainfall, discharge, and windspeed) on macroplastic transport. Additionally, we correlated peaks in plastic to peaks in discharge, wind speed, and rainfall, defined with the 90th percentile of a distribution as the threshold. Finally, we correlated the spatial variation in plastic transport/density with MPW and population density. Contrary to previous studies, our results showed no seasonal differences in plastic pollution within the Odaw catchment. Additionally, only weak to no correlations were found between plastic transport and the hydrometeorological variables. Overall, only 14-18% of the plastic peaks corresponded to the hydrometeorological peaks. More of these plastic peaks were associated to windspeed peaks. However, a strong correlation was observed between MPW and plastic transport and riverbank/land plastic density. Therefore, we hypothesize that anthropogenic factors are more important than hydro meteorological factors in plastic pollution variations. Our study emphasizes the need to holistically study the role of both anthropogenic and hydrometeorological factors in explaining plastic transport and retention dynamics at a river basin scale. This insight is vital for developing effective interventions to address plastic pollution in river catchments.
What repeating earthquakes can tell us about postseismic slip and fluid circulation in the Ecuadorian subduction zone
Authors: Chalumeau Caroline , Agurto-Detzel Hans , De Barros Louis , Charvis Philippe ,   Rapid Response Team of the 2016 Pedernales Earthquake
Published: March 2024

The Ecuador-Colombia subduction zone is a complex and spatially heterogeneous region that hosts both shallow aseismic slip and large megathrust earthquakes, and where both  inter-seismic and post-seismic seismicity have been linked to aseismic slip. Repeating earthquakes, which are the result of repeated loading and failure of single asperities on a fault, are a valuable tool in studying aseismic slip as well as in monitoring the evolution of fault properties over time. In this study, we search for repeating earthquakes within one year of aftershocks following the April 16th, 2016 Mw 7.8 Pedernales earthquake, and we analyze their relationship to afterslip and the evolution of their source properties. We calculate waveform cross-correlation coefficients (CC) on 4762 catalog events, and use a threshold CC of 0.95 to sort events into preliminary families, which are then completed using template-matching and relocated using HypoDD. In total, 376 earthquakes were classified into 62 families of 4 to 15 earthquakes. Additionally, the magnitudes, corner frequencies and stress drops of 136 repeaters were determined using spectral ratios.We find an increase in the recurrence time of repeating events with time after the mainshock, highlighting a possible timeframe for the afterslip’s deceleration. However, repeating earthquakes appear to concentrate around the areas of largest afterslip release, where afterslip gradient is the highest. This suggests that while most repeating aftershocks are linked to afterslip release, the afterslip gradient may play a bigger role in determining their location than previously thought. We also find that repeaters in the region near the trench are unusual, in that their stress drops are anomalously low and systematically decrease over the postseismic period, hinting at a potential increase in pore fluid pressure in this region over time. 
Sedimentary record and sequence stratigraphy of the Middle Triassic carbonate ramp in Sardinia (Italy)
Authors: Stori Lorenzo , Martín Chivelet Javier , López-Gómez José , Ronchi Luigi Ausonio
Published: March 2024

The Triassic succession of Sardinia (Italy) displays the typical “Germanic-like” facies tripartition (Buntsandstein-Muschelkalk-Keuper), which enables regional and interregional correlations with the Central Europe and the western Mediterranean sectors. This work explores the Middle Triassic (Muschelkalk) sedimentary record of this island, which has long been studied and recognized as a key-stratigraphic point for reconstructing the palaeogeographical evolution of the Western Tethys Sea during that time. We conducted a stratigraphic survey fieldwork on 12 sections representing the different formations, and integrated the new obtained palaeontological, geochemical, sedimentological and stratigraphical data with a comprehensive literature review. Moreover, a detailed facies analysis has been performed through field observation and petrographic analysis, following previous approaches to the regional sedimentology. As result, it has been possible to observe that the Sardinian Muschelkalk, interpreted as a carbonate ramp, comprises five main broad sedimentary environments: sabkha, carbonate tidal flat, shallow lagoon, shallow  calcarenitic shoals, and storm-dominated mid-ramp. The obtained data made possible to carry out a sequence stratigraphic analysis, which revealed a major transgressive-regressive cycle of about 5-6 million years (late Illyrian to latest Longobardian), comparable to a 2nd order cycle in the sense of Vail et al. (1991). This sequence is well developed and continuous in the north of the island (Nurra Region) and has its interregional equivalent in different basins of the Mediterranean and Levantine-Balearic domains of neighbouring Iberia (Mega-Depositional Sequence-II of Escudero-Mozo et al., 2015). However, we also noted the absence of outer ramp systems in Sardinia, unlike in other areas of the western Mediterranean.The result of our study helps to better understand the paleogeography of the westernmost transgression of the Tethys Sea during the Middle Triassic, as well as the corridors available for the migration and distribution of the Alpine and Sephardic faunas during the time of the recovery after the Permian-Triassic transition crisis. References:Escudero-Mozo, M.J., Márquez-Aliaga, A., Goy, A., Martín-Chivelet, J., López-Gómez, J., Márquez, L., Arche, A., Plasencia, P., Pla, C., Marzo, M., Sánchez-Fernández, D., 2015. Middle Triassic carbonate platforms in eastern Iberia: Evolution of their fauna and palaeogeographic significance in the western Tethys, palaeogeography, Palaeoclimatology, Palaeoecology 417, 236–260.Vail, P.R., Audemard, F., Bowman, S.A., Eisner, P.N., Perez-Cruz, C., 1991. The stratigraphic signatures of tectonics, eustasy and sedimentology–an overview. En: Einsele, G., Ricken, W., Seilacher, A. (Eds.), Cycles and Events in Stratigraphy. Berlin, Springer-Verlag, 617–659
Scaling up enhanced rock weathering: field trials and ecohydrological modelling in a temperate forest 
Authors: Jones Gregory , Paschalis Athanasios , Waring Bonnie
Published: March 2024

Enhanced Rock Weathering (ERW) utilizing basalt in forest ecosystems has emerged as a potentially scalable strategy for carbon dioxide removal (CDR) in the context of anthropogenic climate change. Despite a robust theoretical understanding of weathering processes across geological timescales, a critical lack of empirical ERW data exists for assessing its efficacy in climate mitigation at relevant timescales. Here, we present the first large-scale, replicated field trial of ERW coupled with tree planting at an afforestation experiment in mid-Wales. The factorial experimental design integrates basalt application and tree functional types (broadleaf vs. coniferous), examining key parameters such as soil pore water pH, alkalinity, soil respiration and aboveground tree biomass. By employing novel sampling techniques, we quantify ERW extent, providing nuanced insights. Over the first three years, initial observations highlight nutrient cycling perturbations post-basalt addition, offering immediate insights into ERW effects in a forested ecosystem. To mechanistically elucidate these observations, we introduce a novel ERW module within the Tethys-Chloris ecohydrological model framework, integrating a microbially explicit soil biogeochemical component. This integrated model aims to provide a robust foundation for understanding how ERW dynamics influence ecosystem carbon sequestration and guide best sampling practices.
Tectonics and exhumation processes in the northern Andes
Authors: Margirier Audrey , Strecker Manfred R. , Thomson Stuart N. , Reiners Peter W. , Casado Ismael , George Sarah , Alvarado Alexandra
Published: March 2024

The Cenozoic growth and uplift of the Andes has been strongly influenced by the subduction dynamics and the superposed effects of climate. Previous studies have shown that the arrival of oceanic ridges and slab flattening triggered regional uplift and exhumation in Peru and Chile. Recent studies suggest that the subduction of the Carnegie Ridge below the Ecuadorian Andes controlled the formation of a crustal sliver moving northward. However, the timing of the ridge’s arrival at the trench and its effect on topographic growth remain unclear.New geo-thermochronological data allows us to investigate the possible role of ridge subduction in prompting the growth of the Ecuadorian Andes and to pinpoint the timing of the Carnegie Ridge subduction. Time-temperature inverse modeling of this new thermochronological dataset constrained two cooling phases in the Western Cordillera. The first phase occurred after the emplacement of intrusions, likely associated with magmatic cooling. The second phase began ~6 Ma, coinciding with the last cooling phase observed in the Eastern Cordillera and is likely to be associated with exhumation of the Western Cordillera. Based on our results and existing geological cross-sections we propose that recent crustal shortening and rock uplift led to exhumation of Ecuadorian Andes at ~6 Ma. We suggest that the onset of Carnegie Ridge subduction at ~6 Ma increased the coupling at the subduction interface, promoting shortening and rock uplift in the region.
The influence of rainfall factors on soil resistance to erosion 
Authors: Živanović Nikola , Rončević Vukašin , Ferreira Carla , Kašanin-Grubin Milica , Ćorluka Stevan , Rupar Veljko , Čebašek Vladimir
Published: March 2024

For the purposes of researching the influence of rainfall factors on soil shear strength, i.e. soil erosion resistance, research was conducted on plots measuring 1.0x0.3 m at a slope of 15°, with equally prepared soil. It’s been carried out 12 rainfall simulations with different values of rainfall factors (rainfall intensity and drops diameter). These simulations were carried out with a modified rain simulator with sprayers by Živanović et. al (2021). The analysis of the uniformity of the prepared soil, as well as the examination of the influence of simulated rainfall factors on soil erosion, was carried out by measuring with a pocket vane tester (Eijkelkamp M1.14.10.E). The measurement was carried out at 30 regularly spaced locations on every plot, immediately after the simulation was completed. Also, the measurement was carried out after 24 hours in three places (upper, middle and lower third of the plot). Spatial distribution of measured values was assessed by Christians' coefficient of uniformity CU. The measured shear strength values of the prepared soil range from 2.1 to 6.9 kN/m2. The shear strength values immediately after the simulation range from 0.4 to 5.4 kN/m2, while after 24 hours they range from 2.4 to 8.1 kN/m2. The CU values of the prepared soil range from 68% to 81% (average 75%). Immediately after the simulation, Cu values range from 73% to 83%, while after 24 hours, from 69% to 91%. In general, there is a clear trend of decreasing values measured with the pocket vane tester from the top to the bottom of the plots. Also, the influence of the change in soil moisture on the values of soil shear strength was observed. The change in rainfall factors affects the change in soil resistance to erosion.
The El Niño response to tropical volcanic eruptions and geoengineering 
Authors: Kroll Clarissa , Jnglin Wills Robert
Published: March 2024

Following tropical volcanic eruptions and in response to geoengineering efforts in climate models, the occurrence of El Niño is notably enhanced. However, the precise mechanisms leading to the preference of the El Niño state remain a subject of ongoing debate. In this study, we explore the El Niño response within the context of stratospheric aerosol injection experiments using the Community Earth System Model version 1, with the Whole Atmosphere Community Climate Model atmospheric component (CESM1 WACCM). Our investigation is centered around the Stratospheric Aerosol Geoengineering Large Ensemble Dataset encompassing three distinct scenarios: a simulation of the RCP8.5 scenario as baseline climate change scenario, a geoengineering scenario, in which surface temperature increases are completely compensated and a scenario focusing solely on the stratospheric heating derived from the geoengineering approach. Our analysis reveals that the El Niño response is primarily linked to the heating in the tropical tropopause layer and lower stratosphere, and notably, it occurs independently of tropospheric cooling effects. We explain the increased occurrence of El Niño after volcanic eruptions and simulated geoengineering interventions by a slow down of the tropical atmospheric circulation, which is caused by increases in gross moist stability due to aerosol heating in tropical tropopause layer.
Landslide inventory following the May 2023 Romagna hydrometeorological event (Northern Italian Apennines): the unavoidable requirement for laborious manual mapping
Authors: Berti Matteo , Corsini Alessandro , Pizziolo Marco , Tommaso Simonelli , Ciccarese Giuseppe , Critelli Vincenzo , Dal Seno Nicola , Fabbiani Cecilia , Generali Mauro , Ioriatti Elena , Lelli Francesco , Mulas Marco , Rani Rodolfo , Ronchetti Francesco , Scaroni Michele , Tondo Melissa , Zuccarini Alessandro
Published: March 2024

Accurate and timely landslide inventory is crucial, particularly after large-scale disasters like earthquakes or heavy rainfalls. While remote sensing enhances mapping speed, accuracy is vital to avoid missing or falsely identifying landslides. Effective mapping depends on factors like immediate access to high-quality imagery and skilled surveyors for ground truth definition.In May 2023, Italy's Emilia-Romagna region experienced a severe hydrogeological emergency, which triggered thousands of landslides. The landslide inventory, crucial for emergency management, faced challenges due to the high number of landslides. Initial efforts using Copernicus Emergency Management Service and national resources faced limitations in completeness and reliability. Ultimately, the official inventory was based on a detailed manual mapping from high-resolution aerial imagery.This work presents the magnitude of the triggering event, the types of the landslides occurred with respect to the geological constraints and discusses the potential benefits and limitations of automated landslide mapping methods in such scenarios. Specifically, more than 50.000 landslides have so far been mapped over an area of around 1000 km2, which range from debris slides/avalanches to debris flows and rock block slides. The impact on infrastructures was significant especially on the road network. With respect to automatic mapping, two distinct techniques have been tested: the conventional NDVI (Normalized Difference Vegetation Index) method and the more sophisticated U-Net algorithm using different remote sensing images ranging in resolution from 10 to 0.2 m.Results show that time-consuming creation of an extensive ground truth datasets is essential in order to evaluate the accuracy of automatic landslide mapping based on images of different resolution and quality, so to determine whether these methods can offer efficient alternatives to manual mapping in large-scale emergency situations.
Towards Accurate Flood Mapping in Arid Regions: Sentinel-1 SAR-based insights and explainable machine learning. 
Authors: Garg Shagun , Dasgupta Antara , Selvakumaran Sakthy , Motagh Mahdi , Martinis Sandro
Published: March 2024

Floods are not only frequent but also one of the costliest natural disasters. The use of satellite remote sensing is a cost-effective and widely adopted method for near real-time flood monitoring. Optical satellite imagery excels at distinguishing water from other land cover types by leveraging the spectral behavior in visible and infrared ranges. However, a major limitation of optical sensors is their inability to penetrate through clouds. This results in images with missing information, impeding their use for flood monitoring. In the past decade, Sentinel-1 Synthetic Aperture Radar (SAR) imagery has emerged as a valuable tool in operational flood management, overcoming the challenges posed by optical sensors. SAR is an active imaging technique that provides cloud-free images day and night by utilizing specular reflection from smooth water surfaces. In SAR imagery, water appears dark due to its unique backscatter characteristics. While SAR amplitude has been widely used for flood detection and monitoring, it tends to overestimate flooded areas, especially in arid and semi-arid regions, because the radar backscatter over sand and open water surfaces is similar. 

In our study, we explore the potential of Sentinel-1 amplitude and interferometric coherence in arid-flood mapping. We conduct multiple case studies and employ the random forest method to train, test, and validate our model predictions against flood masks derived from cloud-free optical imagery. We design several scenarios to investigate the contribution of different layers of information in improving flood mapping accuracy in arid regions along with feature importance analysis to understand the role of each feature to reduce model complexity. Our results demonstrate the effectiveness of fusing amplitude and coherence information in flood mapping,  as compared to coherence or amplitude alone. By utilizing the key features derived using permutation feature importance, flood mapping accuracy was significantly improved by approximately 50%, while also reducing response time, which is crucial for effective emergency management. The findings hold promise and emphasize the versatility of the proposed approach across different sensors and scenes. This offers significant potential for global flood mapping in arid regions, particularly in countries with limited resources. As future missions and advancements in SAR systems continue to evolve, the detection capabilities for floods will further improve, leading to enhanced flood management in arid areas. 
Fluvial versus coastal input of permafrost organic carbon - insights from the Canadian Beaufort Sea
Authors: Madaj Lina , van Crimpen Fleur , Whalen Dustin , Bröder Lisa , Langens Thomas , Bosse-Demers Thomas , Vonk Jorien
Published: March 2024

Around 65% of the Arctic coastline consists of permafrost. Rising global air temperatures cause these permafrost grounds to thaw which leads to the release of organic matter and sediments into the coastal ocean. This influences coastal ecosystem functioning and may further enhance atmospheric warming due to greenhouse gas emissions when the released carbon decomposes. Permafrost organic carbon enters the coastal ocean either through coastal erosion or through fluvial discharge and both fluxes are expected to increase in the future. The Canadian Beaufort Sea receives material from both sources, the region has some of the highest erosion rates in the Arctic and receives additional input through the Mackenzie River, the largest sediment supplier to the Arctic Ocean. To reliably estimate the current and future impacts of permafrost carbon on the coastal ocean and its potential climate feedback, we need to distinguish between these two sources whose fluxes may respond differently to ongoing Arctic change. However, we still lack reliable methods to do so.Here we propose a multiproxy approach to distinguish between sources of permafrost organic carbon by combining organic with inorganic geochemical tracers, grain size and grain shape data on a land-coast-ocean transect in the Mackenzie River Delta. The combined data pinpoints to differences in sediment source, composition, degradation, and transport pathways of both fluvially-discharged and coastally-eroded carbon. Degradation processes of organic and inorganic matter are tightly coupled, but do change within different environments (salinity, energy regimes). By combining degradation state (stable isotopes) and transport indicators (such as grain roundness) with source region tracers (XRF, radiogenic isotopes) we aim to gain insights into the interaction, transition, and origin of this different kind of matter. If successful, this approach can be applied and compared to other Arctic delta environments to fully understand the impacts of increased permafrost thaw and changing river discharge patterns on the coastal Arctic Ocean.
Seasonal effects of wind-blown dust emissions on size-resolved aerosol acidity over the U.S
Authors: Kakavas Stylianos , Siouti Evangelia , Nenes Athanasios , Pandis Spyros
Published: March 2024

Wind-blown dust emitted by the Earth’s surface is one of the major sources of dust emissions especially in non-vegetated areas like deserts and can affect both climate and human health. Acidity is an important property of atmospheric aerosols impacting a series of related processes and can be affected by these emissions of alkaline dust. In this work, we use a wind-blown dust emissions model to quantify the wind-blown dust emissions over the continental United States during February and July 2017. The modeling domain covers a region of 4752 × 2952 km2 including northern Mexico and southern Canada with a horizontal grid resolution of 36 × 36 km. Then, the hybrid version of aerosol dynamics in PMCAMx (Particulate Matter Comprehensive Air-quality Model with Extensions) chemical transport model is used to simulate size-resolved aerosol acidity. In this version of PMCAMx for fine (PM1) particles, bulk equilibrium is assumed, while for larger particles a dynamic model is used to simulate the mass transfer to each size section. Two cases of simulations are performed. The first is the base case simulation and includes the wind-blown dust emissions for both months. The second one neglects these emissions in order to study their effects on aerosol acidity during a wintertime and a summertime period as a function of particle size and altitude.
Coupled dynamics of indicator bacteria populations in water columns and bottom sediments of a mountain creek
Authors: Pachepsky Yakov , Harriger M. Dana , Panko Graf Christina , Stocker Matthew
Published: March 2024

Water columns and bottom sediments in freshwater bodies are two interacting environmental compartments that exchange microorganisms during both high-flow events and periods of base flow. The objective of this work was to quantify the coupled dynamics of FIB populations in water columns and bottom sediment using the three years of weekly monitoring E. coli and enterococci at forested, agricultural, and suburban land use locations along the montane creek in Pennsylvania, USA. Sediment was sampled in triplicate from the surface 0-1.5 cm layer. For both E. coli and enterococci, two population characteristics were used: (a) logarithm of concentrations in MPN per unit of mass of water or sediment, (logCwater and logCsediment) and (b) areal density in MPN cm-2. The annual cycle of logCwater and logCsediment annual cycle mimicked the sine-like changes in air temperature with amplitudes of 3 to 3.5 orders of magnitude. For both organism groups, relationships between water and sediment populations were convex; slopes of linear regressions of logCwatervs. logCsediment varied from 0.756 to 0.918 and from 0.274 to 0.533 for E. coli and enterococci, respectively; the least of the nonlinearity was observed at the forested site. Weekly increments of the E. Coli logCsediments nonlinearly increased with the total precipitation over the week with the rate of about 0.012 per mm precipitation. In the absence of precipitation during the week E. coli logCsediment decreased with weekly rates of 0.205±0.040 and 0.089 ±0.065 over warm and cold periods respectively. The ratio of the areal densities of FIB populations in water and sediment was overall large at the agricultural and suburban sites compared with the forested site.  The ratio tended to increase as the water stage increased. The bulk of the E. coli and enterococci populations was in the water column at agricultural and suburban sites and in the sedimentsat low flows. 
Develop A Citizen Science Toolbox for Change in the Danube Basin Ecosystem 
Authors: Vries Sandra , Gajdusek Felix
Published: March 2024

Imagine that you run a museum along the Danube. You know that the Danube and its ecosystem play an important role in the area and for the people that live there. You would like to involve these people in an active way in the ecosystem recovery of the Danube and its basin, aiming to increase and change their awareness and knowledge. But how?At this point the EU Horizon project DANUBE4all (https://www.danube4allproject.eu/) may step in, dedicated to developing a strategic Danube Basin Restoration Action Plan in close collaboration with stakeholders, by fostering Citizen Science as an element in community co-design. It will be able to trigger the change by integrating action on environmental concerns with social and economic wellbeing; embracing a science-to-people approach that actively integrates public interests and empowers all Danube basin inhabitants and communities to monitor the change in the ecosystem around the Danube.For this, we are working on a Citizen Science Toolbox, a changemaker that can be used by communities, CSOs, museums, nature parks, and many other organizations in the Danube basin. We will share the set-up of this toolbox, which will consist of a decision tree of options of (existing) citizen science monitoring tools, programs, apps, and methods useful to contribute to ecosystem restoration. The decision tree will guide these museums and other community groups to choose what level of involvement they want and how they make use of the tools and methods. Next to that, there will be a sensor multi-tool connection kit for water quality monitoring added, where we assist people in how to make use of existing low-cost sensors, what quality they have, and what fitness for use. We focus in this Toolbox not only on the technical knowledge that these museums and their participants need, but also on how to relate to the actual need within the basin, and to connect them to researchers, research questions, and make it so that their collected citizen science data becomes valuable for the ecosystem restoration in the Danube Delta. To connect them to sustainable monitoring and research in the basin like for example the Join Danube Survey that is already organized along the Danube and where scientists collaborate to monitor the river status. 
The buttressing capacity of Antarctic ice shelves
Authors: Mitcham Tom , Gudmundsson G. Hilmar , Bamber Jonathan L.
Published: March 2024

Ice shelves can control the flux of ice across the grounding line of the Antarctic Ice Sheet (AIS), and hence the rate of mass loss, through the process of ice-shelf buttressing. Recent, increased mass loss from the AIS, particularly in the Amundsen Sea Embayment and the Antarctic Peninsula, has been attributed to a reduction in buttressing due to ice-shelf thinning, calving or ice-shelf collapse events. To determine how further changes in ice-shelf geometry might affect the contribution of the AIS to global sea levels, it is therefore important to quantify the total amount of buttressing that the ice shelves currently provide and to determine where within the ice shelves that buttressing is generated.Previous work has sought to characterise the buttressing of Antarctic ice shelves by, for example, calculating the sensitivity of grounding line flux (GLF) to small perturbations in ice-shelf thickness, or defining regions of passive shelf ice. In this work, we calculate the total buttressing capacity of all Antarctic ice shelves for the first time and then explore the spatial distribution of that total buttressing capacity within each ice shelf.We use the ice-flow model Úa to conduct a series of diagnostic, idealised calving experiments on a present-day, Antarctic-wide model domain, with high spatial resolution over ice shelves and grounding lines. We calculate the total buttressing capacity of each ice shelf as the relative change in GLF in response to the complete removal of the shelf and find that the total buttressing capacity varies by over two orders of magnitude around the ice sheet.We then conduct a series of idealised calving perturbations, using a range of procedures for generating new calving front locations, and explore the spatial distribution of the total buttressing capacity within each ice shelf. We find that the vast majority of the buttressing is typically generated in ice shelf regions within a few kilometres of the grounding line. Thus, we suggest that a greater area of Antarctica’s ice shelves could be considered passive than previously proposed.

 
 
 
Aviation NOx emissions and their increasing impact on global surface air quality
Authors: Eastham Sebastian , Chossière Guillaume , Speth Raymond , Jacob Daniel , Barrett Steven
Published: March 2024

Although the impacts of aviation NOx on local air quality are well-researched, the effects on climate and global air quality are disputed. With the aviation sector under pressure to reduce its contributions to climate change, some studies have suggested that fuel efficiency be prioritized over reductions in aviation NOx emissions. As a result, while emissions of NOx have declined rapidly in other sectors, the amount of NOx emitted per kilogram of aviation fuel burned is estimated to have increased by 17% between 1990 and 2018 with corresponding - and continuing - growth in environmental impact. We use a global atmospheric chemistry-transport model to simulate, at high resolution, the global air quality impacts of aviation, finding that emissions of cruise altitude NOx specifically are associated with the majority of aviation's air quality impacts. Contrary to prior work we find that global simulation at high resolution (~50 km) results in an increase in the simulated impacts relative to simulations at low resolution (~400 km), and that - subject to the choice of epidemiological data source - aviation-attributable ozone may be responsible for global health impacts comparable in magnitude to the total national health burden of US combustion emissions. This presentation will explore the atmospheric mechanisms behind these effects, degree to which model resolution does or does not affect the simulated impacts, the implications for future aviation NOx regulation, and the dominant sources of uncertainty in the result.
Assessment of sewer network data quality on urban pluvial flood modeling with a 2D/1D dual drainage model
Authors: Montalvo Carlos , Tamagnone Paolo , Cea Luis
Published: March 2024

Urban pluvial floods are one of the most common water-related hazards and are going to become more frequent and severe looking at the upsetting climate projections. These events mainly occur due to intense and short precipitation events, leading to the overload of the sewer network and resulting in physical, economic, and even human losses. To address this hazard, effective methods are needed to estimate the scale and impact of pluvial flood events and to develop mitigation strategies. In this context, 2D/1D dual drainage models have become one of the most useful tools for these purposes, being able to simulate all hydraulic phenomena occurring on and beneath the surface. However, these models require detailed information about the topography and geometrical specifications of the sewer network, which are not always readily accessible or, when available, are often incomplete or of poor quality, particularly in large urban environments.In this work, considering that pluvial flood studies are becoming more popular and several numerical tools are available, we wanted to address a recurrent question raised by the flood modeler community: is the effort/level of complexity of implementing a detailed dual drainage model worth it? To answer this question, we assess the influence of sewer network data quality on the results of water depth and velocity obtained with a 2D/1D dual drainage model applied to urban flood modelling. For this purpose, an ad-hoc 2D/1D hydraulic model was implemented to simulate the complex network system of the city of Differdange (LU) exploiting the recently developed Iber-SWMM. This city was chosen as study case because it has experienced several flooding events in recent years, such as those recorded in 2021, and it has an extensive dataset of detailed geospatial data available, enabling the setup of a high-resolution resolution and fully coupled 2D/1D dual drainage model.Sewer network links were classified based on their physical properties, such as diameter and length. The sewer network layout was gradually simplified, starting from the minor links to the more complex segments of the network, obtaining new simplified versions of the network that could represent incomplete or poor-quality scenarios. These simplified versions were successively implemented in the 2D/1D model. The comparison between the results of the complete and comprehensive model and the simplified scenarios reveals the impacts of the quality of the sewer network information on pluvial flood modeling.
Indian ocean sea surface temperature control on the 50,000-year strontium isotope Chew Bahir lake record, Eastern Africa
Authors: Zachow Charlotte , Vonhof Hubert , Galer Stephen J. G. , Foerster Verena , Markowska Monika , Junginger Annett
Published: March 2024

The role that climate played in human evolution has been controversially discussed among scientists for decades. Inspired by these discussions, the Hominin Sites Paleolakes Drilling Project (HSPDP) conducted five deep drilling campaigns adjacent to key hominin fossil sites in eastern Africa, including the Chew Bahir Basin in southern Ethiopia. Analysis of the Chew Bahir lacustrine sedimentary record revealed that over the past 620,000 years, phases of environmental stability and instability occurred contemporaneously with milestones in human history, including pulsed dispersal events out of Africa coinciding with potential humid periods. Although proxies from Chew Bahir sediments have provided important qualitative information about relative changes in environmental conditions, we still lack quantitative information on water availability and an understanding of the dominant climatic forcings controlling water balance. Here we present the first radiogenic strontium isotope (87Sr/86Sr) record covering the past 50,000 years from four Chew Bahir sediment short cores (CB01, CB03, CB05, CB06) and one long core HSPDP-CHB-1A in a resolution of 100 to 1000 years measured on fish bones, endogenic calcites, and ostracods. We interpret the Sr isotope proxy to reflect water provenance changes, particularly controlled by the varying contribution of water overflowing from a series of lakes further north in Ethiopia. Our new Sr-isotope record shows a remarkable correlation with global sea level variability and does not show a pattern of precession paced cycles. Superimposed on this pattern, we see concurrent excursions in the Sr-isotope record of centennial- to millennial scale events such as Heinrich Event 1 (H1) or the Younger Dryas (YD). As Chew Bahir dominantly receives Indian Ocean moisture, the most likely driver of moisture availability in this part of eastern Africa is the temperature of western Indian Ocean surface water that varies in pace with glacial-interglacial climate change. Also on shorter time scales, reduced Indian Ocean surface temperatures correspond to reduced moisture in the tropical rainbelt resulting in dry conditions around H1 and the YD. Where other paleohydrological proxy data from lake fossils can be comparatively noisy because of the high spatial and seasonal variability in such tropical systems, the relatively conservative hydrochemistry of the Sr isotope signal in lakes like Chew Bahir makes this proxy relatively insensitive to seasonal variability while it faithfully captures decadal to longer time scale signals.  
Climate change drives hydrological decoupling of a central European beech forest
Authors: Sauer Daniela , Drollinger Simon , Dietze Michael , Seidel Dominik , Schwindt Daniel , Birk Jago
Published: March 2024

Climate change models suggest increasing rain variability for Europe in the next decades, with hypothesised cascading effects on ecosystems. We evaluate decadal-scale data of a measuring plot in a beech forest in central Germany to test these model-based suggestions and potential implications by empirical evidence.Based on 15 min resolution metrics of precipitation and subsequent water pathways towards and within the soil, we show medium-term trends in rainfall characteristics and their modulation by biota.Rain event durations and rain amounts per event tended to decrease over the observation period, while rain intensity increased, accommodating the effect of the two former parameters on annual precipitation. This change in precipitation patterns, together with canopy structure caused a systematic decrease in throughfall ratios and an exponentially enhanced throughfall variability.Our results suggest that changing rainfall and throughfall patterns will progressively decouple hydrological links in one of Europe’s most extensive ecosystem types. Based on the observed trends, we discuss effects of changing vegetation-modulated rain-input on ecosystem functioning and soil-hydrological trajectories to be anticipated in the near to mid-term future.
Abundance of giant mineral dust particles: Insights from measured emitted dust size distributions during the J-WADI campaign
Authors: Meyer Hannah , Alastuey Andres , Dupont Sylvain , Etyemezian Vicken , Girdwood Jessica , González-Flórez Cristina , González-Romero Adolfo , Hussein Tareq , Irvine Mark , Kandler Konrad , Knippertz Peter , Möhler Ottmar , Nikolich George , Querol Xavier , Stopford Chris , Vogel Franziska , Weis Frederik , Wieser Andreas , Pérez García-Pando Carlos , Klose Martina
Published: March 2024

Gaining a precise understanding of the particle size distribution (PSD) of mineral dust at emission is critical to assess its climate impacts. Despite its importance, comprehensive measurements at dust sources remain scarce and usually neglect part of the super-coarse (particle diameter d between 10 and 62.5 μm) and the entire giant (d > 62.5 μm) particle size ranges. Measurements in those size ranges are particularly challenging due to expected relatively low number concentrations and low sampling efficiencies of instrument inlets.This study aims to better constrain the abundance of super-coarse and giant dust at emission as part of the Jordan Wind erosion And Dust Investigation (J-WADI, https://www.imk-tro.kit.edu/11800.php) field campaign conducted north of Wadi Rum in Jordan in September 2022. The goal of J-WADI is to improve our fundamental understanding of the emission of desert dust, in particular its full-range size distribution and mineralogical composition.To capture the dust PSD across the entire size spectrum, we deployed multiple aerosol spectrometers, including active, passive, and open-path devices, such that in combination, a size range from approximately 0.4 to 200 μm was covered. Here we investigate the variability of the PSD in the super-coarse and giant ranges from observed dust events, address instrumental uncertainties and the impact of different inlets on the resulting PSDs. Our preliminary results reveal a mass concentration peak at around 30 μm, potentially limited toward larger sizes by substantially reduced inlet efficiencies. Giant dust particles were generally detected during active dust emission starting from friction velocities larger than around 0.2 m s-1.Based on our results, we will investigate the mechanisms facilitating super-coarse and giant dust particle emission and transport. Quantifying the conditions for and the amount of super-coarse and giant dust at emission will lay the foundation to incorporate its impacts in weather and climate models.
Adjustment of the Marine Atmospheric Boundary-Layer to the North Brazil Current during the EUREC4A-OA Experiment
Authors: Giordani Hervé , Conejero Carlos , Renault Lionel
Published: March 2024

The EUREC4A-OA experiment (January - February 2020. Bony et al., 2017) took place in the Northwest Tropical Atlantic. Atmospheric simulations were performed at kilometric scale during the EUREC4A-OA experiment (47 days) in order to estimate the sensitivity of the Marine Atmospheric Boundary-Layer (MABL) thermodynamics and circulation to the SST front associated with the North Brazil Current (NBC) and to the SST diurnal cycle. It will be shown that the NBC SST front and associated eddies «Couloir des Tourbillons» strongly control the MABL properties (Surface Pressure, Surface Heat Fluxes, Temperature, Wind, Vertical Shear, Precipitable Water, Liquid Water Content ...), while the diurnal cycle of the SST alters these properties by 5 to 10%.A full MABL water budget has shown that the precipitable water (PW) results of the balance between the total Advection and entraiment at the MABL top, which drains water out the MABL, and surface evaporation that fills in the MABL. It will be shown that the NBC increases the loss of water by advection and by entrainment and increases the gain of water by surface evaporation, by 80 mm in 47 days. The diurnal cycle of SST amplifies these responses by 30 mm in the NBC.Some components of the MABL energy budget will be also presented.