bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Resolution Chemical Mapping and Identifying Spatial Distribution of Microbes in the Zea mays Rhizosphere using Correlative Microscopy
Authors: Imihami Mudiyanselage Chiththaka Chaturanga D B , Schmidt Matthias , Davoudpour Yalda , Stryhanyuk Hryhoriy , Richnow Hans , Musat Niculina
Published: March 2021

Studying the spatial distribution of bacteria and characterizing the soil chemistry (i.e., elemental, isotopic and molecular composition) underpins the comprehensive understanding of rhizosphere associated processes. During the past decades, several stand-alone methods have been developed to investigate soil chemistry, nutrient cycling and plant nutrition. However, individual approaches as stand-alone are not capable of providing an overall rhizosphere processes involving soil, root and microbes in a spatial context, as there is no common sample preparation method available to satisfy individual needs of each technique. Here, we present i) a sample preparation method, which includes soil embedding, sectioning and ii) a correlative imaging and image registration workflow, which allows for characterization of minerals, roots and microbes by different high-resolution imaging and microanalytical techniques. This allows for conducting rhizosphere studies on different scales, focusing on root-soil-microbe interfaces with spatial resolution of nano-meter scale. Hydrophilic, immunohistochemistry compatible, low viscosity LR White resin was used to embed and stabilize the soil and make it ultra-high vacuum compatible. We employed water-jet cutting as a novel approach to slice the embedded samples, and, by doing so, avoided polishing of the surface which often leads to translocation of sample material (smearing). The quality of this embedding was analyzed by and Helium Ion Microscopy (HIM). Epifluorescence microscopy in combination with Catalyzed Reporter Deposition-Fluorescence in-situ Hybridization (CARD-FISH) was employed to accurately identify and determine the spatial distribution of bacteria in the embedded sample, thus avoiding ambiguities from high levels of auto-fluorescence emitted by soil particles and organic matter. Chemical mapping of the rhizosphere was acquired by SEM/EDX, ToF-SIMS, nanoSIMS for elemental, molecular and isotopic characterization, respectively, and µ-Raman microscopy for specific identification of minerals.

In summary, we demonstrate that LR White embedding and water-jet cutting of soil in combination with CARD-FISH and a correlative microscopic workflow, allows for a comprehensive characterization of biotic and abiotic components in the rhizosphere. The developed sample preparation method can facilitate the various requirements of involved microscopy techniques and individual workflows for imaging and image registration to analyze data. We foresee that this approach will establish an excellent platform to study various soil processes and synergistic understanding of complex rhizosphere processes.
Reference material for the measurement of soil hydraulic properties
Authors: Lamparter Axel , Stange C. Florian
Published: March 2021

Quality control of the measurement of soil hydraulic properties (water retention curve, saturated hydraulic conductivity) using soil cores is not very common in soil physics laboratories. The missing quality control in the labs might be due to the lack of a suitable reference material for the measurement of soil hydraulic properties (SHP). However, a standardized quality of these measurements is needed, especially when generated data from different laboratories are used.

So far no satisfying reference material has been presented that can be used for quality control during the measurement of SHP. Reference material should have a rigid pore system and pore surfaces properties that do not change over time. Additionally, the reference material should be very sensitive to provide a sufficient quality control for the measurement of SHP.

We present sintered glass cylinders with a defined pore size distribution that were tested in the laboratory for reproducibility. After a standardized cleaning procedure of the glass cylinders, water contents after equilibration at -63 hPa (field capacity) showed reasonably low standard deviations. Thus, it seems promising that these cylinders can be used as reference material for the measurement of the water retention curve.

First Results of repeated saturated hydraulic conductivity measurements (Ks) of the same sintered glass cylinders showed larger variability and an increasing trend over the time. Currently the reason for this trend is unknown. Therefore, it is worked on standardizing procedures of using the reference cylinders and on cleaning the cylinders to improve the reproducibility. The results show how sensitive the measurement of saturated hydraulic conductivity is and that we need to put more emphasis on quality control in our work.

 
On the use of drones to detect and map marine macro-litter on the North Atlantic Portuguese beach-dune systems: the experiences of UAS4Litter project
Authors: Andriolo Umberto , Gonçalves Gil , Bessa Filipa , Sobral Paula , Pinto Luis , Duarte Diogo , Fontán-Bouzas Angela , Gonçalves Luisa
Published: March 2021

Unmanned Aerial Systems (UAS, aka drones) are being used to map marine macro-litter on the coast. Within the UAS4Litter project, the application of UAS has been applied on three sandy beach-dune systems on the wave-dominated North Atlantic Portuguese coast. Several technical solutions have been tested in terms of drone mapping performance, manual image screening and marine litter map analysis. The conceptualization and implementation of a multidisciplinary framework allowed to improve and making more efficient the mapping of marine litter items with UAS on coastal environment. 

The location of major marine litter loads within the monitored areas were found associated to beach slope and water level dynamics on the beach profiles. Moreover, the abundance of marine pollution was related to the geographical location and level of urbanization of the study sites. The testing of machine learning techniques underlined that automated technique returned reliable abundance map of marine litter, while manual image screening was required for a detailed categorization of the items. 

As marine litter pollution on coastal dunes has received limited scientific attention when compared with sandy shores, a novel non-intrusive UAS-based marine litter survey have been also applied to quantify the level of contamination on coastal dunes. The results showed the influence of the different dune plant communities in trapping distinct type of marine litter, and the role played by wind and overwash events in defining the items pathways through the dune blowouts. 

The experiences on the Portuguese coast show that UAS allows an integrated approach for marine litter mapping, beach morphodynamic and nearshore hydrodynamic, setting the ground for marine litter dynamic modelling on the shore. Besides, UAS can give a new impulse to coastal dune litter monitoring, where the long residence time of marine debris threat the bio-ecological equilibrium of these ecosystems.
Modeling of the upper ocean winter (sub)mesoscale variability in the central Arctic Ocean during the MOSAiC drift.
Authors: Kuznetsov Ivan , Fang Ying-Chih , Rabe Benjamin , Androsov Alexey , Hoppmann Mario , Mohrholz Volker , Tippenhauer Sandra , Schulz Kirstin , Fofonova Vera , Janout Markus A , Fer Ilker , Baumann Till , Stanton Timothy P , Liu Hailong , Mallet Maria
Published: March 2021

The dynamics of the boundary layer of the ocean significantly affect the interaction between ocean and atmosphere and, as a result, global climate. The sub-ice boundary layer of the ocean and its dynamics have not been thoroughly studied because of the extremely difficult conditions for observation, in particular during winter. Current understanding of spatial-temporal variability of (sub)mesoscales of the upper Arctic Ocean is extremely limited.
At the same time, one of the most important features of the upper ocean layers are the small-scale processes that influence and possibly determine the vertical and horizontal transport of heat, salt, and biologically relevant substances. As a consequence, mathematical models, in particular climate models, experience serious difficulties in parameterization of processes not resolved by the models because of the lack sufficient knowledge to detail the spatial variability at the (sub-)mesoscale.
To a better characterization and understanding of (sub)mesoscale dynamics and its role in vertical transport of energy and mass we apply a 3D regional ocean model FESOM-C. The observed vertical hydrological structure and a corresponding reconstructed horizontal temperature and salinity fields were imposed as a part of the forcing for the numerical model. These fields and information about the vertical hydrological structure were utilized by the model as initial conditions and for constraining (nudging) during the spin-up period. After the initial spin-up period, once the model had adjusted to our initial conditions, we performed several free runs.
We expect that our 3D numerical studies of eddy properties will contribute to a better characterisation and understanding of (sub)mesoscale dynamics in the Arctic Ocean and its role in the vertical transport of energy and mass.
Lessons learned from the study of 68 Cenozoic occurrences of subduction initiation
Authors: Lallemand Serge , Arcay Diane
Published: March 2021

To address the question of the triggers and mechanisms involved in the process of subduction zones formation, we have explored all available clues attesting for subduction initiation (SI) during the Cenozoic. We have defined several stages starting from incipient-diffuse, incipient-localized, achieved to self-sustained subduction. We have also included prematurely extinct, i.e., aborted, subduction attempts in order to better understand the reasons for the stoppage of subduction process, and thence to specify the conditions of success. This comprehensive study led us to observe that new subductions regularly initiate at a mean rate of about once per million years. Two third of those initiated during the Cenozoic are still active. A majority initiated at the transition between an ocean and a continent, a plateau or a volcanic arc. Lithospheric forces are needed for SI with the help of mantle forces in one third of the cases. Multiple triggers, like a collision followed by a slab breakoff, are common. The stress at SI is compressional in most cases if not all and oriented oblique to the nascent plate boundary in more than half of the cases. The nascent plate boundary generally reactivates a former lithospheric fault, most often with a change in its kinematics (conversion of spreading center, normal or detachment fault or transform fault) or using the same kinematics when reactivating former subduction faults. There is no rule regarding the age of the subducting plate which varies from 0 to 140 Ma in the studied examples. In the same vein, the subducting plate is not necessarily older than the overriding plate. Both situations are equally observed.
Transforms are forever
Authors: Vannucchi Paola , Iacopini David , Morgan Jason P.
Published: March 2021

According to Plate Tectonics, fracture zones (FZs) are born at Transform Faults (TFs), which leave behind "inactive" FZs traces as scars on the seafloor that reflect their initial use as one side of a strike-slip transform fault. FZs were originally thought to "heal" as the oceanic lithosphere cooled and strengthened with time. However, the occurrence of recent earthquakes reveals that FZs can be associated with significant seismic activity (for example during the recent Mw 8.6 2012 EQ offshore Sumatra and Mw 7.9 2018 EQ offshore SE Kodiak), and also with permanent deformation that occurs well after passage through the TF.

The TF at the spreading center is known to be accompanied by the formation of the transform valley which exposes serpentinized peridotite to the ocean floor. Valley relief itself can drive fluid flow that promotes continued serpentinization, and also cooling- and volume-change-linked stress variations. Off-axis seismicity suggests that FZs remain weaker that neighbouring oceanic lithosphere. The transform valley relief in general persists as a fracture zone valley that itself can continue to be a major drive of fluid flow even in the “healed” oceanic lithosphere. After reviewing evidence for FZ activity on (normal) ocean floor we will focus on the long-lived impact of FZs at continental margins. Offshore/onshore evidence of ongoing deformation at FZs is observed through seismic activity at both the western Brazilian and eastern Ghana-Côte d’Ivoire ends of the Romanche FZ. The western Brazil end is also characterized by recent folding and faulting, both offshore across the FZ, and onshore co-linearly with FZ extensions into the continent. Seismic activity in continental Brazil is focused where the FZ intersects the continental margin. This activity suggests that FZs remain as permanent weak lithospheric heterogeneities that are able to store elastic strain.

The reasons why FZs remain active are still poorly understood. Possible causes include i) effects of serpentinization that occurs both in the TF and in the FZ through hydrothermal fluid/mantle interaction, ii) thermal stress, iii) changing tectonic stresses related to plate driving forces.
The extent of methane emission associated with the natural gas industry in southeastern Poland.
Authors: Jagoda Paweł , Nęcki Jarosław , Bartyzel Jakub , Korbeń Piotr , Kud Michał , Florczyk Grzegorz , Król Stanisław
Published: March 2021

Goal of the CCAC project is to observe urban emission of natural gas over Canada and different countries in Europe. Our team was responsible for the Silesia and Sub-Carpathia regions in southern Poland. In this presentation we will focus on the methane emission measurements from gas pipelines, storages, gas wells as well as gathering and processing facilities, which was realized by our team in years 2018-2020.

South eastern Poland is rather rural part of the country with rich history of oil and gas industry going back to the XVI-th century. Currently Carpathians and Carpathian Foredeep regions gas industry produces 1.35 BILLIONS of m3 [1]

The measurements have been carried out since summer 2016 mainly with Micro-Portable Greenhouse Gas Analyzer ‘Los Gatos Research, MGGA-918’ mounted on board of a car. We also had capability to deploy analyser in difficult terrain with its own power supply. During our measurements our team visited over 300 gas wells. We found that over half of these sites show elevated methane concentrations which can be attributed to either gas well itself or soil fractures around site. Transects paths were designed to follow pipelines. This allowed us to monitor possible leaks from the natural gas infrastructure. However there are numerous possible sources in close proximity of pipelines. We will discuss detection methods and variability study for dozens of transects. As of the 2017 only 9 gathering and processing facilities report release which states the emission of 1.8*106 m3 CH4 per year. One of the focus points of our project was to estimate how uncertain were methane emission from O&G in Poland which at current phase concludes methane emission of 7.5-40 kt CH4/year

During the presentation we will outline challenges in carrying out measurements with GPM, OTM 33a methods that were performed alongside large-area screening. We are developing oversized flow chamber method. Mobile structure is built in the shape of a dome. It has the radius of 3 meters which gives the chamber volume of 49 m3.

This work was funded under the Climate and Clean Air Coalition (CCAC) Oil and Gas Methane Science Studies.

[1]PSG, „Bilans zasobów złóż kopalin w Polsce wg stanu na 31 XII 2019 r,” PIG-PIB, Warsaw, 2020.

 
Moment Magnitude Estimates in the Marmara Sea Region (NW Turkey) Using Coda Wave Analysis
Authors: Özkan Berkan , Eken Tuna , Gaebler Peter , Taymaz Tuncay
Published: March 2021

Reliable magnitude estimates of the earthquakes are of utmost important for seismic hazard studies, particularly, in tectonically active areas such as the Marmara region of NW Turkey. The region is highly populated and contains a major fault associated with destructive earthquakes. In this study we apply a coda wave modelling approach based on acoustic radiative transfer theory to calculate the source displacement spectrum, and thus to obtain moment magnitudes of small earthquakes within the Marmara region. We examine three-component waveform data extracted from local earthquakes with magnitudes 2.5 ≤ ML ≤ 5.7 recorded in a radius of 150 km. For each event in the region, an inversion is performed in several different frequency bands. Our results indicate significant similarity with the local magnitude values reported by the KOERI. Consequently, we focus on establishing a novel relation between Mw and ML in the Marmara region.
Partitioned Permeability Diagram: an innovative way to estimate Fault Zones hydraulics.
Authors: Aubert Irène , Lamarche Juliette , Leonide Philippe
Published: March 2021

Understanding the impact of fault zones on reservoir trap properties is a major challenge for a variety of geological ressources applications. Fault zones in cohesive rocks are complex structures, composed of 3 components: rock matrix, damage zone fractures and fault core rock. Despite the diversity of existing methods to estimate fault zone permeability/drain properties, up to date none of them integrate simultaneously the 3 components of fracture, fault core and matrix permeability, neither their evolution with time. We present a ternary plot that characterizes the fault zones permeability as well as their drainage properties. The ternary plot aims at (i) characterizing the fault zone permeability between the three vertices of matrix, fractures and fault core permeability ; and at (ii) defining the drain properties among 4 possible hydraulic system: (I) good horizontal and vertical, fault-perpendicular and -parallel; (II) moderate parallel fluid pathway; (III) good parallel fault-core and (IV) good parallel fractures. The ternary plot method is valid for 3 and 2 components fault zones. The application to the Castellas Fault case study show the simplicity and efficiency of the plot for studying underground and/or fossil, simple or polyphase faults in reservoirs with complete or limited permeability data.
What’s in a lake? Glacial Lake Outburst Floods in the Peruvian Andes.
Authors: Wood Joanne , Harrison Stephan , Wilson Ryan , Glasser Neil , Reynolds John , Diaz Moreno Alejandro , Emmer Adam , Cool Simon , Torres Juan Carlos , Caballero Adriana , Jara Harrinson , Yarleque Christian , Melgarejo Enver , Villafane Hilbert , Araujo Julia , Turpo Efrain , Tinoco Tito
Published: March 2021

Climate change is resulting in mass loss and the retreat of glaciers in the Andes, exposing steep valley sides, over-deepened valley bottoms, and creating glacial lakes behind moraine dams. Glacial Lake Outburst Floods (GLOFs) present the biggest risk posed by glacier recession in Peru. Understanding the characteristics of lakes that have failed in the past will provide an aid to identifying those lakes that might fail in the future and narrow down which lakes are of greatest interest for reducing the risks to local vulnerable populations. 

Using a newly created lake inventory for the Peruvian Andes (Wood et al., in review) and a comprehensive GLOF inventory (unpublished) we investigate lakes from which GLOFs have occurred in the past. This is to establish which physical components of the glacial lake systems are common to those lakes that have failed previously and which can be identified remotely, easily and objectively, in order to improve existing methods of hazard assessment.
Long-term evolution of the gas composition of Popocatepetl's plume
Authors: Taquet Noemie , Stremme Wolfgang , Rivera Claudia , Bezanilla Alejandro , Grutter Michel , Campion Robin , Valade Sebastien , Boulesteix Thomas , Legrand Denis , Blumenstock Thomas , Hase Frank
Published: March 2021

Changes in the eruptive dynamics are mainly controlled by the magma gas content, and the degassing processes impacting the magma viscosity and ascending speed. The progressive exsolution of the gas species, their release at different depths, their mutual interaction and the eventual assimilation of crustal rocks are reflected in the volcanic plume composition changes. Combining long-term ground-based FTIR and UV remote measurements of the Popocatepetl's plume, seismic data and visual monitoring, we explore the relationship between the gas composition changes in the volcanic plume and the transition between extrusive and passive degassing regimes.

SO2, HCl, HF, BrO, SiF4 and CO2 are simultaneously measured in the volcanic plume since 2013 from the Altzomoni observatory, located 12 km north of the crater. We capture several phases of lava dome growth, different types of explosions and passive degassing periods. The evolution of the gas species ratios through these events allows deciphering the degassing processes.
Modelling of greenhouse gas emissions from European croplands with the biogeochemical model ECOSSE
Authors: Kuhnert Matthias , Martin Michael , Mcgrath Matthew , Smith Pete
Published: March 2021

Greenhouse gas (GHG) emissions contribute to climate change. Agricultural production contributes 10 – 14 % of the global anthropogenic GHG emission, including 37 % from soils (Paustian et al., 2016). Monitoring and analysis of emissions from agriculture is the basis for reducing GHG emissions and applying mitigation options. Measuring and estimating emissions from the agricultural sector are challenging and modelling is a useful tool to capture the heterogeneity of the dynamics. Agricultural management is the main driver for the carbon and nitrogen dynamics in croplands, which makes model approaches difficult, as potentially there is great heterogeneity in the influencing factors, but also a lack of robust data for management data for larger scales. Additionally, measurements of GHG emissions are scarce, on small (spatial and temporal) scales, or do not reflect the entire range of system variable combinations. This hinders the evaluation of large scale simulation results. The objective of the study was to simulate the GHG emissions (CO2 and N2O) for European croplands and use national inventory data for the evaluation of the results. We used the model ECOSSE which is based on the carbon model RothC and the nitrogen model SUNDIAL. For yield production, the primary production model MIAMI is coupled with ECOSSE. The model structure allows small scale differences (resolution for simulation is 0.1°) to be captured, while simulating monthly time steps. This balances the uncertainty of the available input data with the accuracy of the simulated results. The model shows reasonable results for the CO2 emissions, but underestimates heterotrophic respiration, which leads to an overestimation of carbon fluxes to the soil. Nitrogen emissions are underestimated due to underestimation of fertilizer applications in some hot spots. The comparison with national inventories that depend mainly on statistics using simpler approaches shows differences to the simulation approach, which indicates the strong dependency of the emissions on the management data. The model approach provides the spatial distribution of the emissions as well as inter-annual dynamics. The changes on the model showed already the improved performances by the model and the extension to include more target variables. More sub-national and sub-annual data sets for evaluation will allow a further improvement of the model performance. 
Flow partitioning in partially saturated fracture networks: Relation between dispersive properties and internal fracture geometry
Authors: Kordilla Jannes , Dentz Marco , Tartakovsky Alexandre M.
Published: March 2021

Modeling of of infiltration and recharge dynamics in fractured-porous aquifers remain an extremely challenging task due to the formation of preferential pathways along fracture networks and hence deviation from classical diffuse Darcy-type percolation patterns. In contrast to soil systems the vadose zone of consolidated rock systems often reaches depths of several tens to hundreds of meters which limits the accessibility and complicates the application of moisture measurement techniques. Under partially-saturated conditions flow through percolating fracture networks contribute to the fastest spectrum of infiltration velocities. At fracture intersections flow is often fragmented into a vertical and horizontal component which controls the dispersive properties of the infiltrating fluid front. As hydraulic information in consolidated aquifers is often only available at boreholes or springs, we explore how internal fracture network geometries can potentially be reconstructed from external boundary information, e.g., the dispersive properties of discharge (groundwater level fluctuations). In order to relate boundary information, e.g. discharge measured at the water table within boreholes, to internal properties such as geometry of the fracture network and fluid-solid interaction properties we derive an approximate analytical solution for flow through a cascade of simple fracture intersections with the help of parallalized smoothed particle hydrodynamics simulations [1]. Via linear response theory we derive expressions for the non-dimensional bulk flow velocities and dispersion coefficient to characterize the fracture network in terms in the dimensionless time scales of the vertical and horizontal fracture components. We demonstrate that the dispersion coefficient converges towards a universal value for a realistic range of fluid and solid properties and recover a characteristics Washburn-type scaling for the dimensionless velocity.

[1] Kordilla, J., Tartakovsky, A. M. and Dentz, M. (2020): Numerical and analytical modeling of flow partitioning in partially saturated fracture networks, Earth and Space Science Open Archive, pp. 44, doi:10.1002/essoar.10504345.1
Trends in mean and extreme rainfall over Mainland Southeast Asia associated with warming-driven trends in evaporation 
Authors: Skliris Nikolaos , Marsh Robert , Haigh Ivan , Wood Melissa , Hirschi Joel , Darby Stephen , Quynh Nguyen Phu , Hung Nguyen Nghia
Published: March 2021

Rain-gauge datasets indicate strong increases in both annual mean and extreme precipitation over large parts of the Mainland Southeast Asia (MSEA) including Vietnam and the northwestern part of the peninsula over the last 40 years. Increasing precipitation is associated with increased monsoon intensity in southeast Asia and a northward shift of the monsoon activity centre towards MSEA. Warming-driven evaporation increases over the three main oceanic moisture sources - the Arabian Sea, the Bay of Bengal, and the South China Sea- may partially explain increasing precipitation in large parts of MSEA. Changes in the patterns of the two main modes of natural variability in the tropical Indian Ocean – the Indian Ocean Basin Mode (IOBM) and the Indian Ocean Dipole (IOD) – contribute to surface warming in these oceanic moisture source regions supplying precipitation to MSEA. Climate model projections show robust wide-spread trends in wet season precipitation with increasing frequency and intensity of extreme precipitation events throughout MSEA over the 21st century. Similar to observations, the projected precipitation trends are associated with strong warming-driven increases in evaporation in all major oceanic moisture sources supplying precipitation to MSEA.
Lava flow hazard map of Piton de la Fournaise volcano 
Authors: Chevrel Oryaëlle , Favalli Massimiliano , Nicolas Villeneuve , Harris Andrew , Fornaciai Alessandro , Richter Nicole , Derrien Allan , Boissier Patrice , Di Muro Andrea , Peltier Aline
Published: March 2021

Piton de la Fournaise, situated on La Réunion Island (France), is one of the most active hot spot basaltic shield volcanoes worldwide, experiencing at least two eruptions per year since the establishment of the observatory in 1979. Eruptions are typically fissure-fed and form extensive lava flow fields. About 95 % of some ~250 historical events (since the first confidently dated eruption in 1708) have occurred inside an uninhabited horse-shoe shaped caldera (hereafter referred to as the Enclos) which is open to the ocean on its eastern side. Rarely (12 times since the 18th century), fissures have opened outside of the Enclos where housing units, population centers and infrastructure are at risk. In such a situation, lava flow hazard maps are a useful way of visualizing lava flow inundation probabilities over large areas. Here, we present a lava flow hazard map for Piton de la Fournaise volcano based on: i) vent distribution, ii) statistics of lava flow lengths, iii) lava flow recurrence times, and iv) simulations of lava flow paths across multi-temporal (i.e., regularly updated) topography using the DOWNFLOW stochastic numerical model. A map of the entire volcano highlights that the most probable (up to 12 %) location for future lava flow inundation is within the Enclos, where about 100,000 visitors are present each year. Hazard distribution changes throughout the analysis period due to the high frequency of eruptions that constantly modifies the vent opening distribution as well as the topography and the lava flow dimensional characteristics. Outside of the Enclos, probabilities reach 0.5 % along the well-defined rift zones and, although hazard occurrence in inhabited areas is deemed to be very low (<0.1 %), it may be underestimated here, as our study is only based on post-18th century records and neglects cycles of activity at the volcano. Specific hazard maps considering different event scenarios (i.e., events fed by different combinations of temporally evolving superficial and deep sources) are required to better assess affected areas in the future – especially by atypical, but potentially extremely hazardous, large volume eruptions. At such an active site, our method supports the need for regular updates of DEMs and associated lava flow hazard maps if we are to be effective in mitigating the associated risks.
Compact Operational Tropospheric Water Vapor and Temperature Raman Lidar  with Turbulence Resolution
Authors: Lange Diego , Behrendt Andreas , Wulfmeyer Volker
Published: March 2021

We present the Atmospheric Raman Temperature and Humidity Sounder (ARTHUS), a new tool for observations in the atmospheric boundary layer and lower free troposphere during daytime and nighttime with very high resolution up to the turbulence scale, high accuracy and precision, and very short latency and illustrate its performance with new measurements examples. ARTHUS measurements resolve the strength of the inversion layer at the planetary boundary layer top, elevated lids in the free troposphere, and turbulent fluctuations in water vapor and temperature, simultaneously (Lange et al., 2019). In addition to thermodynamic variables, ARTHUS provides also independent profiles of the particle backscatter coefficient and the particle extinction coefficient from the rotational Raman signals at 355 nm with much better resolution than a conventional vibrational Raman lidar.

The observation of atmospheric moisture and temperature profiles is essential for the understanding and prediction of earth system processes. These are fundamental components of the global and regional energy and water cycles, they determine the radiative transfer through the atmosphere, and are critical for the cloud formation and precipitation (Wulfmeyer, 2015). Also, as confirmed by case studies, the assimilation of high-quality, lower tropospheric WV and T profiles results in a considerable improvement of the skill of weather forecast models particularly with respect to extreme events.

Very stable and reliable performance was demonstrated during more than 3000 hours of operation experiencing a huge variety of weather conditions, including seaborne operation during the EUREC4A campaign (Bony et al., 2017, Stevens et al., 2020). ARTHUS provides temperature profiles with resolutions of 10-60 s and 7.5-100 m vertically in the lower free troposphere. During daytime, the statistical uncertainty of the WV mixing ratio is <2 % in the lower troposphere for resolutions of 5 minutes and 100 m. Temperature statistical uncertainty is <0.5 K even up to the middle troposphere. Consequently, ARTHUS fulfills the stringent WMO breakthrough requirements on nowcasting and very short-range forecasting (see www. wmo‐sat.info/oscar/observingrequirements).

This performance serves very well the next generation of very fast rapid-update-cycle data assimilation systems. Ground-based stations and networks can be set up or extended for climate monitoring, verification of weather, climate and earth system models, data assimilation for improving weather forecasts.

References:

Bony et al., 2017, https://doi.org/10.1007/s10712-017-9428-0

Lange et al., 2019, https://doi.org/10.1029/2019GL085774

Stevens et al. 2020, submitted to ESSD

Wulfmeyer et al., 2015, doi:10.1002/2014RG000476
Stochastic characterization of calcite dissolution rate from in-situ and real-time AFM imaging
Authors: Recalcati Chiara , Siena Martina , Bussetti Gianlorenzo , Riva Monica , Duò Lamberto , Guadagnini Alberto
Published: March 2021

Carbonate dissolution processes are key in many environmental areas as well as in the industrial sector. In subsurface environments, a detailed knowledge of mineral dissolution/precipitation kinetic rate laws is a critical component in the context of, e.g., aquifer contamination assessment, geologic carbon sequestration, toxic waste disposal, or hydraulic fracturing of hydrocarbon reservoirs. The recent employment of advanced measurement instruments such as Atomic Force Microscopy (AFM) and Vertical Scanning Interferometry (VSI) enables direct observations of the mechanisms occurring on the mineral surface during the reaction, providing evidence that the dissolution process is strongly affected by several sources of variability at the local (i.e., micro-scale) mineral-fluid interface. In this context result, marked spatial heterogeneities in the dissolution rate are documented. Therefore, a change of perspective towards a quantification based on a stochastic approach is of primary importance. We propose to employ geostatistical tools to characterize the spatial heterogeneity of dissolution rate maps obtained from in-situ and real-time AFM imaging. We collect datasets of the surface topography of a millimeter-scale calcite sample subject to dissolution, from which we evaluate reaction rate maps. Our work is aimed at (1) characterizing the statistical behavior of topography and dissolution rate data and their spatial increments; (2) identifying an appropriate interpretive model for such statistics; and (3) evaluating quantitatively, through observed trends of model parameters, the temporal evolution of the spatial heterogeneity of reaction kinetics.
Volcanic aerosol heating in the tropical tropopause region and associated water vapour changes
Authors: Kroll Clarissa , Schmidt Hauke , Timmreck Claudia
Published: March 2021

Large volcanic eruptions affect the distribution of atmospheric water vapour, for instance through cooling of the surface, warming of the lowermost stratosphere, and increasing the upwelling in the tropical tropopause region.

To better understand the volcanic impact on the tropical tropopause region and associated changes in the water vapour distribution in the stratosphere we employ a combination of short term convection-resolving global simulations with ICON and long term low resolution ensemble simulations with the MPI-ESM1.2-LR EVAens, both with prescribed volcanic forcing. With the EVAens a long term statistical analysis of the water vapour trends during the build-up and decay of a volcanic aerosol layer is made possible. The impact of the heating in the cold point regions is studied for five different eruption magnitudes. Stratospheric water vapour changes are analyzed in simulations with synthetic and observation based aerosol profiles showing that the distance of the aerosol profile from the cold point region can be more important for the water vapour entry into the stratosphere than the emitted amount of sulfur.

Whereas the EVAens is ideal to investigate the slow ascent of water vapour into the stratosphere the 10 km high resolution simulations with ICON allow insights into the convective changes after volcanic eruptions going beyond the limitations parameterizations usually impose on the model data.
Carbon sources and sequestration: 14C Ramped Pyroxidation in aquatic sediments.
Authors: Keaveney Evelyn , Barrett Gerard , Reimer Paula , Blaauw Maarten
Published: March 2021

Sequestration of organic carbon in aquatic sediments can depend on its source and potential lability. Studies have shown that bulk lake and marine sediment comprises carbon of different origin but its source has been difficult to attribute. A new Ramped Pyroxidation/Combustion (RPO) system in the 14CHRONO Centre has been established. RPO is a technique that incrementally heats a sample, and allows for collection of the CO2 produced for radiocarbon analyses. The results show its utility in partitioning carbon sources in lake sediment (Rostherne Mere, UK, Santa María del Orolake, Mexico), and arctic marine sediment (Chukchi Sea and Beaufort Shelf). RPO and 2-stepped combustion1. 14C indicated multiple carbon sources in Rostherne Mere sediment, some of which could be attributed to the construction of a sewage treatment works (STW) on the lake shore, and subsequently inputs from this STW. RPO identified 3 carbon fractions in Mexican Lake sediment, which provided a more accurate chronology, partitioning the contemporaneous sediment date from offsets induced from volcanic activity in the area. Results from Arctic marine sediment demonstrated inputs of carbon from ancient permafrost, providing a means to refine the chronologies and a basis for future research linked with carbon loss from thawing permafrost.

1Keaveney et al. 2020. Journal of Palaeolimnology 64 347-363
Sea–ice concentration at 1 km resolution in summer from merged visible and microwave radiometer observations
Authors: Ludwig Valentin , Spreen Gunnar
Published: March 2021

Sea–ice concentration, the surface fraction of ice in a given area, is a key component of the Arctic climate system, governing for example the ocean–atmosphere heat exchange. Satellite–based remote sensing offers the possibility for large–scale monitoring of the sea–ice concentration. Using passive microwave measurements, it is possible to observe the sea–ice concentration all year long, almost independently of cloud coverage. The spatial resolution of these measurements is limited to 5 km and coarser. Data from the visible and thermal infrared spectrum offer finer resolutions of 250 m–1 km, but need clear–sky scenes and, in case of visible data, sunlight. In previous work, we developed and analysed a merged dataset of passive microwave and thermal infrared data, combining AMSR2 and MODIS satellite data at 1 km spatial resolution. It has benefits over passive microwave data in terms of the finer spatial resolution and an enhanced potential for lead detection. At the same time, it outperforms thermal infrared data due to its spatially continuous coverage and the statistical consistency with the extensively evaluated passive microwave data. Due to higher surface temperatures in summer, the thermal–infrared based retrieval is limited to winter and spring months. In this contribution, we present first results of extending the existing dataset to summer by using visible data instead of thermal infrared data. The reflectance contrast between ice and water is used for the sea–ice concentration retrieval and results of merging visible and microwave data at 1 km spatial resolution are presented. Difficulties for both, the microwave and visual, data are surface melt processes during summer, which make sea–ice concentration retrieval more challenging. The merged microwave, infrared and visual dataset opens the possibility for a year–long, spatially continuous sea ice concentration dataset at a spatial resolution of 1 km.
Legacy effects of multiyear summer drought on soil CO2 production, transport and efflux in a sub-alpine grassland
Authors: Telser Carmen , Harris Eliza , Reinthaler David , Bahn Michael
Published: March 2021

Climate change is expected to lead to an increase in frequency and severity of extreme climatic events like summer drought. Drought and rewetting have strong impacts on soil respiration, which constitutes the largest flux of CO2 from terrestrial ecosystems to the atmosphere. However, little is known about the role of biotic and abiotic factors in driving CO2 production and transport across the soil profile and how these processes are affected by repeated drought events. Soil CO2 transport can be assessed using the flux-gradient approach, a method which assumes that diffusion is the only transport mechanism for CO2 through soil, with diffusion rates primarily dependent on air-filled pore space. It is therefore generally assumed that the calculated soil CO2 concentration gradient translates directly into soil CO2 efflux, however, a discrepancy between measured soil CO2 efflux and modeled soil CO2 concentration gradients can indicate presence of non-diffusive transport mechanisms.

In a multiyear drought and rewetting experiment at a mountain meadow in the Austrian Alps, we compared soil CO2 production, transport and efflux for plots which were exposed to two and twelve subsequent years of experimental summer drought, respectively, versus plots with ambient precipitation and soil moisture. We measured soil respiration using automated chambers and assessed the production and transport of CO2 using the flux-gradient approach on data obtained with solid-state sensors in three soil depths through the soil profile. We tested the hypothesis that drought-driven reduction in soil respiration will be more intense for the 12-year drought treatment, but the CO2 pulse induced by rewetting will be higher. We furthermore expected that non-diffusive transport mechanisms would play a crucial role during drought and would be more pronounced in the 12-year drought treatment compared to the 2-year drought treatment. Data analysis is currently in progress, the findings will be presented at the conference.
A new a-priori velocity model for seismic tomography investigation of the Southern Italy region
Authors: Totaro Cristina , Neri Giancarlo , Orecchio Barbara , Presti Debora , Scolaro Silvia
Published: March 2021

By integrating data and constraints available in the literature, we defined a new “a-priori” 3D seismic velocity model imaging the lithospheric structure of Southern Italy, a highly complex area in the Mediterranean region where the Africa-Europe plate convergence and the residual rollback of the Ionian slab coexist. Involving the integration of multiple datasets and constraints (e.g. velocity patterns from seismic profiles and/or tomographies, moho depth estimates, subduction interface geometries) and following a procedure derived to the one already successfully applied in the area about a decade ago, we obtained the simplest 3D velocity structure consistent with all the available collected data. Studies and analyses performed in recent years allowed us to enlarge and improve the previous estimated model by adding further data and useful constraints. The so obtained "a-priori" velocity model has then been used as starting model for a new earthquake tomographic inversion of the study region. Dataset used for the velocity model computation has been selected from the Italian seismic database (www.ingv.it) and consists of ca. 10000 earthquakes with magnitude equal or greater than 2 and occurred in the time period 2000-2020 at depth less than 60 km and with at least 10 station readings. The obtained 3D velocity structure and the related hypocenter locations have been compared with other geophysical and geological observations and interpreted in the frame of the geodynamic models proposed for the region.
Identification and quantification of sources and sinks of carbonyl sulfide
Authors: Zanchetta Alessandro , Kooijmans Linda M.J. , van Heuven Steven , Scifo Andrea , Scheeren Bert , Mammarella Ivan , Karstens Ute , Meijer Harro A.J. , Krol Maarten , Chen Huilin
Published: March 2021

Carbonyl sulfide (COS) is the most abundant reduced sulfur gas in the atmosphere and is used as a tracer for gross primary production (GPP) of terrestrial ecosystems and stomatal conductance of leaves. At present, its usefulness is limited by the uncertainties in the estimation of its sources and sinks. In this study, we aim to understand the COS budget using atmospheric COS enhancements at the Lutjewad tower (53°24’N, 6°21’E, 1m a.s.l.) and atmospheric measurements of COS in the province of Groningen using a mobile van. We infer the sources and sinks of COS using continuous in situ mole fraction profile measurements of COS at Lutjewad. We determined the nighttime COS fluxes to be -3.0 ± 2.6 pmol m-2 s-1 using the radon-tracer correlation approach. We observed enhancements of COS mole fractions on the order of 100 ppt (lasting a few days) to 1000 ppt (lasting a few hours) at three occasions. To quantify potentially unidentified COS sources, we have made additional measurements by collecting air flasks that were analyzed later in the laboratory and with a continuous quantum cascade laser spectrometer. We have identified multiple COS sources, such as biodigesters, sugar production facilities and silicon carbide production facilities. Furthermore, we simulate the Lutjewad COS mole fractions in a Lagrangian model framework to quantitatively understand the COS sources and sinks. These results are useful for improving our understanding of the sources and sinks of COS, contributing to the use of COS as a tracer for GPP.
SIMILE: An integrated monitoring system to understand, protect and manage sub-alpine lakes and their ecosystem
Authors: Cannata Massimiliano , Strigaro Daniele , Lepori Fabio , Capelli Camilla , Veronesi Mauro , Rogora Michela , Lami Andrea , Brovelli Maria
Published: March 2021

Lakes are a fundamental resource for the Insubric region (cross-border area that includes Ticino, North Lombardy and west Piedmont regions). Therefore the quality of their waters must be protected from the risks caused by the increased anthropogenic pressure and climate change. The main objective of the interreg project named SIMILE (https://interreg-italiasvizzera.eu/database_progetti/simile/) is to support decision making in the definition of management policies through an advanced information system based on data obtained from innovative monitoring systems (automatic, diversified, cost-effective and with high spatial and temporal resolution). The information system will also facilitate the identification of possible critical issues understanding the specific causes in a timely manner by using a common methodology across Switzerland and Italy: specifically for Lake Lugano, Lake Maggiore and Lake Como. The project aims at capitalizing and sharing the experiences of the project partners in the field of monitoring and management of water resources in the project area, in particular in the context of the CIPAIS programs (IT-CH international water protection commission). The information system, fully open, is designed to offer an effective, lowcost and sustainable solution that can be maintained by the project partners beyond the end of the project. From a scientific and technical point of view the project is based on the combination of advanced automatic and continuous observation systems, high resolution remote sensing data processing, citizen science and ecological and physical models. In this presentation we will discuss experiences gained from the deployment of cost-effective monitoring platform and open technologies used for data colection, archive, processing and dissemination.