bluuebunny/crossref_metadata_2025 huggingface dataset:
3D simulation of Levee breach
Authors: Kaurav Rajkumari , Gandhinagar Pranab
Published: March 2020

Levee breaching is the process of erosion of the levee material resulting in its failure and causing the water to flood. A levee may breach due to overtopping, piping, foundation defects, and lack of maintenance. The complex process of levee breaching involves hydrodynamics, sediment transport, and soil water interaction. This paper presents the 3D simulation of levee breach due to overtopping using CFD software, FLOW-3D. The numerical model uses Reynolds-averaged Navier–Stokes equations (RANS) for fluid flow, along with the volume of fluid (VOF) equation for surface tracking, as the governing equations. In addition, several turbulence models and different equations for bedload transport in scour model are available in FLOW-3D for simulation. A grid convergence test is used to decide the mesh size. The turbulence model and the parameters used in sediment scour model are calibrated using the experimental results for breach profiles available in literature. Results for evolution of breach and water surface profiles are presented. Additionally, velocity vectors in breach section, turbulence characteristics along the longitudinal and transverse direction and the breach discharge are also presented. The study suggests that the Renormalized group (RNG) turbulence model along with Meyer-Peter Müller equation for bedload transport optimally simulate the breach process for the considered case.
Progresses in the CMEMS BS-MFC for improving forecasting capabilities and monitoring the Black Sea region through high quality modelling systems
Authors: Ciliberti Stefania Angela , Palazov Atanas , Gregoire Marilaure , Staneva Joanna , Peneva Elisaveta , Masina Simona , Lecci Rita , Marinova Veselka , Matreata Marius , Creti Sergio , Vandenbulcke Luc , Behrens Arno , Palermo Francesco , Jansen Eric , Lima Leonardo , Stefanizzi Laura , Daryabor Farshid , Azevedo Diana , Valcheva Nadezdha , Agostini Paola ,   CMEMS Black Sea Monitoring and Forecasting Center Team
Published: March 2020

The BS-MFC (Black Sea Monitoring and Forecasting Centre) delivers near real time and multi-year products for the Black Sea region with the scope to describe its physical, biogeochemical and wave conditions in the frame of CMEMS. This is done through 3 Production Units – Physics, Biogeochemistry and Waves – that implement state-of-the-art and accurate modelling approaches for forecasting and monitoring purposes. In 2019, the BS-MFC offer has been updated to include i) updated versions of the BS-PHY and BS-WAV NRT products and new BS-BIO product, ii) update of the MY products timeseries up to Dec 2018 and iii) inclusion of Ocean Monitoring Indicators (OMI).

Considering NRT systems, the systems are performing assimilation of in-situ and satellite products provided by CMEMS TACs with PHY and BIO products centered to 12:00Z and WAV product instantaneous fields covering 10-days forecast. BS-BIO offers new product since Jul 2019, including CHL, PHYC, O2, NO3, PO4, Primary Production and carbonate system components (pH, DIC, Alkalinity, air-sea flux of CO2). To support ocean monitoring purposes, describing the current state of the Black Sea physical dynamics, environmental and extreme events, the BS-MFC implements a set of OMI: a) vertically integrated oxygen content, b) oxygen penetration density and depth, c) sea surface temperature and salinity anomalies, d) significant wave height extremes.

To improve forecasting capabilities and prepare the next generation of BS products, the BS-MFC is working on several scientific topics, the most challenged are the increased resolution in vertical of the physical system, the problem of the Bosporus Strait as boundary condition, improved data assimilation capabilities, coupling strategies among PHY, BIO and WAV and improvement of upstream data ingestion in NRT and MY systems, including the usage of hourly forcing in WAV production system and forecast data of the Danube River discharge and nutrients in the PHY and BIO systems. Furthermore, the BS-MFC is working on enforce operational capacities and define pre-operational evaluation to estimate accuracy of operational and new products.

 
Linking molecular properties of soil organic carbon to emergent ecosystem functions in a tidally influenced landscape of the Pacific Northwest
Authors: Sengupta Aditi , Bond-Lamberty Ben , Rivas-Ubach Albert , Zheng Jianqiu , Handakumbura Pubudu , Yabusaki Steven , Bailey Vanessa , Ward Nicholas , Stegen James
Published: March 2020

Coastal landscapes and their terrestrial-aquatic interface (TAI) will be increasingly exposed to short-term tidal inundation due to sea level rise and extreme weather events. These events can generate hot moments of biogeochemical activity and also alter ecosystem structure if occuring frequently. However, such responses of these vulnerable ecosystems to environmental perturbations are poorly understood, limiting our ability to evaluate the contribution of local processes on global scale carbon and nutrient budgets. Here, we evaluated whether and to what degree seawater inundation impacts biogeochemical responses in soils collected along a naturally variable salinity gradient in a first order tidal stream floodplain in the Pacific Northwest. A laboratory incubation experiment simulating episodic inundation was performed to detect the impacts on soil carbon chemistry. We characterized carbon before and after inundation using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS), metabolite signatures via Liquid Chromatography-Mass Spectrometry (LC-MS), and high-frequency carbon dioxide (CO2) and methane (CH4) gas fluxes from intact soil cores. Following three inundation events, we observed significant decreases in the thermodynamic favorability of the remaining organic compounds in soils with high natural salinity as compared to low salinity soils. Low salinity soils showed higher average flux compared to high salinity soils following periodic inundation events. Seawater inundation led to distinct metabolite features in low salinity soils, with surficial soil preferentially getting enriched in phenolic compounds. Biogeochemical transformations inferred from FTICR-MS data showed an increase in total transformations with increasing salinity for soil cores from naturally low salinity exposure sites, likely suggesting higher microbial activity. In conclusion, ecosystem responses in a tidal landscape frequently experiencing seawater inundation preferentially influences terrestrial soils to behave as a carbon source. This response is likely a function of historical salinity gradient-driven molecular-level organic carbon characteristics.
A path to increasing Geological knowledge
Authors: Molina Sonia
Published: March 2020

This is a subject that I work on in 2nd of ESO. The subject’s objectives are;

-Asking about diferent geological contents or others tòpics

-Learning to sequence the tasks in a research

-Learning to work deductively, thoughtfully and competently

-Learning to work cooperatively

-Learning to know to do oral presentation using digital sources and handing-on demostrations

-Finally achieving scientific knowledge.

In order to achieve these goals:

1. I make groups of 4 students.

2. I give a little colour box to each group ( nobody knows what is inside the box).Inside each box, there are differents things like: diferents types of rocks,sand, wàter, fòssils,a picture of a landscape, geological structures,...

3. Each Student has to think 5 questions about the object of the box.

4. After that, every group decides which question wants to do the research about.

5. Five-six days after. The students have to write a litle piece of work about their research, they have to make a poster using a thinking routine ( Roda de la indagació), there we can see the procés of the research.Finally the students explain to the others students their research. Everybody learn for each other.

It’s an interesting activity, the evaluation of this is very satisfactory. The students are actively involved in their learning, their knowledge and the procedure for acquiring them 
Major threats of pollution and climate change to global coastal ecosystems and enhanced management for sustainability
Authors: Lu Yonglong , Yuan Jingjing , Lu Xiaotian , Su Chao , Zhang Yueqing , Quan Yuan , Xie Wushuang
Published: March 2020

Coastal zone is of great importance in the provision of various valuable ecosystem services. However, it is also sensitive and vulnerable to environmental changes due to high human populations and interactions between the land and ocean. Major threats of pollution from over enrichment of nutrients, increasing metals and persistent organic pollutants (POPs), and climate change have led to severe ecological degradation in the coastal zone, while few studies have focused on the combined impacts of pollution and climate change on the coastal ecosystems at the global level. A global overview of nutrients, metals, POPs, and major environmental changes due to climate change and their impacts on coastal ecosystems was carried out in this study. Coasts of the Eastern Atlantic and Western Pacific were hotspots of concentrations of several pollutants, and mostly affected by warming climate. These hotspots shared the same features of large populations, heavy industry and (semi-) closed sea. Estimation of coastal ocean capital, integrated management of land-ocean interaction in the coastal zone, enhancement of integrated global observation system, and coastal ecosystem-based management can play effective roles in promoting sustainable management of coastal marine ecosystems. Enhanced management from the perspective of mitigating pollution and climate change was proposed.
Upcoming food matrix stable isotope reference materials from the USGS: honeys, vegetable oils, flours, and collagens
Authors: Ogrinc Nives , Schimmelmann Arndt , Qi Haiping , Camin Federica , Bontempo Luana , Potočnik Doris , Abrahim Aiman , Cannavan Andrew , Carter James F. , Dunn Philip J.H. , Reid Lauren T. , Coplen Tyler B.
Published: March 2020

An international project developed, quality-tested, and measured isotope−delta values of 10 new food matrix reference materials (RMs) for hydrogen, carbon, nitrogen, oxygen, and sulfur stable isotope-ratio measurements to support food authenticity testing and food provenance verification. These new RMs will enable users to normalize measurements of samples to isotope−delta scales. The RMs span a range of δ2HVSMOW values from −207.4 to −43.3 mUr or ‰, for δ13CVPDB from −30.60 to −13.72 mUr, for δ15Nair from +1.78 to +14.96 mUr, for δ18OVSMOW from +18.20 to +26.33 mUr, and for δ34SVCDT from −20.25 to +17.49 mUr. The RMs include (i) a pair of honeys from Canada and tropical Vietnam, (ii) flours from C3 (rice) and C4 (millet) plants, (iii) four vegetable oils from C3 (olive, peanut) and C4 (corn) plants, and (iv) collagen powders from marine fish and terrestrial mammal origins. After thorough homogenization of the bulk materials, multiple aliquots were sealed in glass under vacuum or noble gas to exclude oxygen and to potentially extend the shelf life to decades when stored at –18 °C in the dark. A total of six laboratories from five countries used various analytical approaches and instrumentation for two- or multiple-point isotopic normalization against international RMs. The use of reference waters and organic liquids in silver tubes allowed direct normalization of δ2H values of organic materials against isotopic reference waters following the principle of identical treatment, minimizing interference from atmospheric moisture. An errors-in-variables regression model that included the uncertainty associated with the measured and assigned values of the RMs was applied centrally to normalize results and obtain consensus values and measurement uncertainties reported here for new RMs USGS82 to USGS91. Because of exchangeable hydrogen and H2O in some RMs (especially in honeys, collagens, and flours), sample loading in contact with laboratory air and different types of pre-treatment can result in significant bulk δ2H variance. Utilization of these new RMs should foster mutual compatibility of δ2H values if harmonized technical/analytical approaches are followed and documented in data reports.
Winter arctic sea-ice cover variability and the prediction of spring vegetation growth over Eurasia
Authors: Ji Liuqing , Fan Ke
Published: March 2020

The changes in Eurasian vegetation not only have important effects on regional climate, but also have effects on global temperatures and the carbon cycle. In this study, the interannual linkage between spring vegetation growth over Eurasia and winter sea-ice cover over the Barents Sea (SICBS), as well as the prediction of spring Euraisan vegetation are investigated. The Normalized Difference Vegetation Index (NDVI) derived from the advanced very high resolution radiometer is used as the proxy of vegetation growth. During 1982–2015, the winter SICBS is significantly correlated with the spring NDVI over Eurasia (NDVIEA). The positive (negative) winter SICBS anomalies tend to increase (decrease) the spring NDVIEA. The increased winter SICBS corresponds to higher winter surface air temperature and soil temperature over most parts of Eurasia, and in turn, corresponds to less winter snow cover and less snow water equivalent. The persistent less and thinner snow cover from winter to spring over Eurasia, especially over Western and Central Siberia, tends to induce increased surface air temperature through decreased surface albedo and less snowmelt latent heat. Subsequently, the increased surface air temperature corresponding to increased SICBS contributes to higher vegetation growth over Eurasia in spring and vice versa. Based on this linkage, seasonal predictions of spring NDVI over Eurasia are explored by applying the year-to-year increment approach. The prediction models were developed based on the coupled modes of singular value decomposition analyses between Eurasian NDVI and climate factors. One synchronous predictor, the spring surface air temperature from the NCEP’s Climate Forecast System (SAT-CFS), and three previous-season predictors (winter SICBS, winter sea surface temperature over the equatorial Pacific (SSTP), and winter North Atlantic Oscillation (NAO) were chosen to develop four single-predictor schemes: the SAT-CFS scheme, SICBS scheme, SSTP scheme, and NAO scheme. Meanwhile, a statistical scheme that involves the three previous-season predictors (i.e., SICBS, SSTP, and NAO) and a hybrid scheme that includes all four predictors are also proposed. To evaluate the prediction skills of the schemes, one-year-out cross-validation and independent hindcast results are analyzed, revealing the hybrid scheme as having the best prediction skill in terms of both the spatial pattern and the temporal variability of spring Eurasian NDVI.
Development of the Deltares global fluvial flood forecast system
Authors: den Toom Matthijs , Verkade Jan , Weerts Albrecht , Schotmeijer Gert-Jan
Published: March 2020

Deltares operates the Global Fluvial Flood Forecasting System (GLOFFIS) is a real-time fluvial forecasting system with global coverage. At any location in the world, for both the recent past and the near future, the system produces estimates of various hydrological parameters. 

The continued investment in GLOFFIS is justified by various reasons. Primarily, there is an R&D rationale. Any operational system that runs in near real-time poses high requirements to the availability of input data and the runtime of the models used. This problem is augmented when applying the system to the global scale: both model domains and data volumes become significantly larger. Also, data originates from a wide variety of sources. Runtimes, however, cannot be significantly larger hence this poses additional requirements to the efficiency of models used. Solving these issues requires a considerable R&D effort. The resulting developments tend to be useful for the ‘local’ systems we develop and maintain for our clients. An additional rationale is found in the increased demand for global forecasts – notably from a client base that is not able or willing to operate forecasting systems themselves. 

At its core, GLOFFIS operates a set of hydrological models that, jointly, cover the entire earth’s land. The models are forced by meteorological data – pertaining to both the recent past and the near future. The models produce estimates of various hydrological parameters such as soil moisture content, surface water runoff and streamflow rates. Future versions of GLOFFIS will include hydrodynamic models, allowing to produce estimates of water level in addition to streamflow rates. Also, future versions will include seasonal forecasts, i.e. forecasts going out several weeks if not months. In addition to real-time data, the system enables the production of long-term timeseries. 

In terms of the infrastructure of the system, GLOFFIS is based on the wflow framework for hydrological modelling which is embedded within a the Delft-FEWS forecast production system. Neither of these require any licensing fees and the wflow framework is available through an open source license. The Delft-FEWS system is used for many operational flood forecasting systems including those of the US National Weather Service, the English Environment Agency, the Bureau of Meteorology and many other national forecasting agencies. Wflow is a distributed modelling framework specifically designed to accommodate multiple model schematization types and data assimilation techniques. For GLOFFIS, we opted for the physically based wflow_sbm that uses kinematic wave routing for surface and subsurface flow. So-called pedotransfer functions that translate input base maps to model parameter values ensure that the models require little calibration.
UAV-based imagery analysis with machine learning to facilitate microbial water quality monitoring of irrigation ponds
Authors: Pachepsky Yakov , Morgan Billie , Stocker Matthew , Kim Moon
Published: March 2020

Surface waters can contain pathogenic microorganisms that may ​be detrimental to individuals consuming produce grown with irrigation. Fecal indicator organisms, primarily Escherichia coli, are commonly used to estimate the potential presence of pathogens in irrigation waters.  Concentrations of E. coli in the water of irrigation ponds are often highly variable in space and time. Water sampling that is frequent in time and dense in space, is impractical. Unmanned aerial systems (drones, or UAVs) have shown the potential to provide informative imagery. We hypothesized that the UAV-based imagery can facilitate the microbial water quality monitoring in ponds by reflecting the differences in bacteria habitats. ​Six times over the summer, we coupled monitoring of 17 water quality parameters ​of 23 locations across an irrigation pond in Maryland with 14 images ​captured by a MicaSense RedEdge M and modified GoPro cameras. The modified GoPro Images were demosaiced into red, green, and blue bands for each of the cameras. The random forest methodology was used to evaluate the accuracy and reliability of relationships between several combinations of measured ​explanatory variables, and the logarithm of the E. coli concentration as the variable to predict. Random forest models with only imagery data as the ​explanatory variables, and ​models with all measured data as explanatory variables had coefficients of determination between 0.5 ​to 0.6, and 0.6 ​to 0.7, respectively. The most important explanatory variables for the model with only imagery input were digital numbers ​obtained from the blue band of the “visible only” filter image, and from the red bands of the “infrared only” and “visible only” filter images.  When all measurements were used, the most important explanatory variables were concentrations of chlorophyll a and fluorescent dissolved organic matter, as well as and digital number​s from the red band ​of the “infrared only” filter image. There appears to be a potential for the UAV-based imagery to provide dense spatial coverage of ponds with subsequent delineation of a small number of relatively uniform zones for informed water sampling. 
Dependency of the turbulent heat exchange over polar leads on the lead width – an LES study
Authors: Gryschka Micha , Zhou Xu , Sühring Matthias
Published: March 2020

Leads are Chanel-like openings in the sea-ice through which heat of several 100 Watt/m2 is transferred from the ocean into the atmosphere. Even though leads account only for a view percent to the total ice coverage in polar regions, they modify the polar boundary layer significantly. Therefore, leads need to be considered in numerical weather and climate models. Since, generally leads are not explicitly resolved in these models it is important to understand the overall effect of leads of different sizes onto the boundary layer for different meteorological conditions.

With numerous Large-Eddy Simulations we investigated the dependency of the lead averaged surface heat flux on the lead width in a range between 50 m and 25 000 m for different meteorological conditions. Generally, we found under same temperature differences between ice and water and same meteorological conditions an increase of the the lead averaged heat flux with increasing lead width by more then 200% for some situations. We like to give some brief explanations of the possible causes for this behavior as well as to oppose these results to other former studies in this field, which might disagree to them in some points.
The first multi-model ensemble of regional climate simulations at kilometer-scale resolution, Part I: Evaluation of precipitation
Authors: Ban Nikolina , Brisson Erwan , Caillaud Cécile , Coppola Erika , Pichelli Emanuela , Sobolowski Stefan , Adinolfi Marianna , Ahrens Bodo , Alias Antoinette , Anders Ivonne , Bastin Sophie , Belusic Danijel , Berthou Ségolène , Cardoso Rita , Chan Steven , Christensen Ole , Fernandez Jesus , Fita Lluis , Frisius Thomas , Goergen Klaus ,   Erika Coppola
Published: March 2020

Here we present the first multi-model ensemble of climate simulations at kilometer-scale horizontal resolution over a decade long period. A total of 22 simulations, performed by 21 European research groups are analyzed. Six different regional climate models (RCMs) are represented in the ensemble. The simulations are compared against available high-resolution precipitation observations and coarse resolution (12 km) RCMs with parameterized convection. The model simulations and observations are compared with respect to mean precipitation, precipitation intensity and frequency, and heavy precipitation on daily and hourly timescales in different seasons.

The results show that kilometer-scale models produce more realistic representation of precipitation than the coarse resolution RCMs. The most significant improvements are found for heavy precipitation and precipitation frequency on both daily and hourly time scales in the summer season. In general, kilometer-scale models tend to produce more intense precipitation and reduced wet-hour frequency compared to coarse resolution models. Although differences between the model simulations at the kilometer-scale and observations exist, it is evident that they are superior to the coarse-resolution RCMs in the simulation of precipitation in the present-day climate, and thus offer a promising way forward for investigations of climate and climate change at local to regional scales.
Geographical scientific publications in ORBi, the ULiège institutional repository: analysis of the socio-economic influencing factors of downloads
Authors: Stirbu Simona
Published: March 2020

Institutional repositories usage statistics, especially the number of views of references or downloads of documents and various associated data, constitute a wealth of information nowadays.

Our study aims to analyze different aspects of the downloads of scientific publications (journal articles and communications) in geography from ORBi, the institutional repository of the University of Liège, Belgium. We also verify in which proportion these downloads are influenced by some socio-economic factors of the “dowloading” countries.

We choose to work on a sample of 453 publications uploaded by the geographers from the ULiège(Belgium) Department of Geography in the institutional repository between 2000 et 2014.

In order to achieve our main objectives, we have first identified the language of the references and the number of downloads by country. We then performed statistical analysis, multivariate regression, to verify if socio-economic factors like, the size of the population, PIB, the internet access, etc., could influence the number of downloads depending on the language of the documents or the localization of the countries on different continents.

The results indicate that the language of the documents influences the number of downloads effectuated and their worldwide distribution.

On average 76% of the references downloads are explained by the characteristics of the countries that have effectuated these downloads, mainly the language, scientific production and population size of the countries.
Passive sampling as a tool for determination of micro-organic compounds in groundwater resources
Authors: Mali Nina , Koroša Anja , Auersperger Primož
Published: March 2020

Micro-organic (MO) compounds have been recognized as an important factor in environmental pollution. Developments in a range of analytical techniques are expanding the number of MOs that can be detected in groundwater. They may not be new contaminants, but recently detected using improved sampling and analytical methods. Monitoring programmes for groundwater are largely based on the collection of grab (spot) samples. One of the methods to determine the presence of organic compounds in groundwater v can also be passive sampling. Contrary to grab sampling, passive sampling is less sensitive to accidental extreme variations of the organic compounds concentrations in groundwater and it also allows determination of a large range of contaminants at once. A passive sampler can cover a long sampling period, integrating the pollutant concentration over time. This paper presents the application of the passive sampling technique for monitoring organic pollutants within the four major alluvial aquifers in Slovenia used for water supply. Passive samples were analyzed by gas chromatography mass spectrometry (GC-MS). For the interpretation of chromatograms, the AMDIS deconvolution was used. The deconvolution was covered by the GC-MS library with retention times for 921 organic contaminants from Agilent USA, as well as by the NIST 2008 library of mass spectra. Most frequently detected MO substances were classified in different pollutant groups with respect to their origin (urban source, agriculture or industry). Based on the results, a comparison of the presence of MOs in the present aquifers was made. Passive sampling with active carbon fibres was proved to be an appropriate method for monitoring micro-organic pollutants in groundwater.
Evaluation of the changes in the Radiocaesium Interception Potential (RIP) of Japanese and European soils based on their potassium content, mineralogy and agricultural zeolite amendments
Authors: Dengra i Grau Francesc Xavier , Eguchi Tetsuya , Toloza Arsenio , Smolders Erik , Tarjan Sandor , Shinano Takuro , Gerzabek Martin , Bruun Hansen Hans Christian , Dercon Gerd
Published: March 2020

After the Fukushima Daiichi Nuclear Power Plant (FDNPP) aftermath in 2011, potassium addition has been increasingly valued as the most effective countermeasure for soil remediation of polluted sites. Potassium is a competing cation with caesium during plant root uptake. Recent studies have elucidated that potassium application can increase the Radiocaesium Interception Potential (RIP), a key parameter that determines the radiocaesium selectivity in soil and therefore its phytoavailability. The RIP is determined as the product of the distribution coefficient of caesium and the concentration of potassium in soil solution, considering the occupation in exchange regular sites but especially in the so-called frayed-edged of the 2:1 phyllosilicate layers of clay minerals, that account for most of the high-selectivity sites for caesium. In order to increase soil RIP, mineral amendments -especially zeolite- were applied in Japanese target fields as a major measure for safe agricultural production. In this study, we aimed at the determination of the RIP of Japanese and European soils with different clay mineralogy, as a key parameter for the solid-liquid distribution of radiocaesium in soils. To do so, we analysed the clay mineralogy of soils by X-Ray diffraction (XRD), as well as the solid and soil solution phases of five types of soils with different potassium fixing capacity by atomic absorption spectrometry (AAS) and ionic chromatography (IC), respectively. As potassium fixation varies among soils, we expected very different relationships between their potassium content and RIP. Their RIP was determined by spiking with 1-2 KBq of radiocaesium-134 prior to the use of thallium doped sodium iodine scintillator (NaI(Tl)). Both solid phase exchangeable caesium and soil solution caesium were analysed by inductively coupled plasma mass spectrometry (ICP-MS). Partial findings for Japanese soils showed a potassium fixing rate of approximately 93% for vermiculitic soils, while for imogolitic Andosols with low 2:1 phyllosilicate clay mineral content, only 17% of potassium addition was determined to be fixed. The fixation capacity for smectitic soils reached 57%. Furthermore, additional research is currently being done regarding RIP determination of several agricultural soils and with and without zeolite amendments. The final results will be shown in the EGU General Assembly 2020.
Recent results from scientific ESA Swarm projects
Authors: Trenchi Lorenzo , Bouffard Jerome , Stromme Anja , Marghitu Octav , Kauristie Kirsti , Blăgău Adrian , Vogt Joachim , Heilig Balázs , Kovács Péter
Published: March 2020

This presentation illustrates the recent results obtained in the context of scientific ESA Swarm projects. The project “Swarm data quality Investigation of Field-Aligned Current products, Ionosphere, and Thermosphere system” (SIFACIT) has been recently extended in order to achieve two additional objectives: To provide to users an open-source program package to estimate Field Aligned Current (FAC) density and quality indicators, using single- and multi-s/c methods from Swarm data; To study the Joule heating of the ionosphere–thermosphere system on multiple scales, using Swarm data, together with conjugate ground information and simulations.

The other project illustrated here is EPHEMERIS (nEw sPace weatHER inforMation Exploited from the SwaRm observatIonS). This project is investigating the Midlatitude Ionospheric Trough (MIT) with Swarm data, and will also develop a new MIT Swarm data product based on Swarm L1b Langmuir Probe (LP) data. The second part of the project will develop a quasi-real-time intermittency index (IMI) for the detection of ionosphere plasma irregularities along the Swarm orbit, which can be responsible for errors and loss of lock in GPS signals. A statistical comparison of the IMI index with GPS signal from ground based receivers will be performed, in order to identify the ionospheric irregularities at Swarm altitude responsible for scintillations in GPS signals.
Magma Degassing as a Source of Long‐Term Seismicity at Volcanoes: The Ischia Island (Italy) Case
Authors: Di Vito Mauro , Trasatti Elisa , Acocella Valerio , Del Gaudio Carlo , Weber Gregor , Aquino Ida , Caliro Stefano , Chiodini Giovanni , de Vita Sandro , Ricco Ciro , Caricchi Luca
Published: March 2020

Transient seismicity at active volcanoes poses a significant risk in addition to eruptive activity.
This risk is powered by the common belief that volcanic seismicity cannot be forecast, even on a long
term. Here we investigate the nature of volcanic seismicity to try to improve our forecasting capacity. To this
aim, we consider Ischia volcano (Italy), which suffered similar earthquakes along its uplifted resurgent
block. We show that this seismicity marks an acceleration of decades‐long subsidence of the resurgent block,
driven by degassing of magma that previously produced the uplift, a process not observed at other
volcanoes. Degassing will continue for hundreds to thousands of years, causing protracted seismicity and
will likely be accompanied by moderate and damaging earthquakes. The possibility to constrain the future
duration of seismicity at Ischia indicates that our capacity to forecast earthquakes might be enhanced when
seismic activity results from long‐term magmatic processes, such as degassing.
Elevated CO2 increases plant growth but reduces soil C storage under N limiting conditions
Authors: Eder Lucia M. , Weber Enrico , Rousk Johannes , Schrumpf Marion , Zaehle Sönke
Published: March 2020

Rising atmospheric CO2 concentrations may induce or aggravate nitrogen (N) limitation to plant growth. To overcome this limitation, plants may invest their newly assimilated carbon (C) into N acquiring strategies, such as root growth, root exudation or C allocation to mycorrhizal symbionts. These shifts in C allocation can increase the turnover of soil organic matter by stimulating microbial activity. As these processes are poorly quantified, their net effects on ecosystem C storage remain uncertain.

To gain a better quantitative understanding of these processes, we assessed the effect of elevated CO2 on plant C and N allocation in a mesocosm experiment. For four months of one growing season, 64 saplings of Fagus sylvatica L. were grown in a natural beech forest topsoil. Plants were exposed to near ambient (390 ppm) or elevated (560 ppm, eCO2) CO2 concentrations at two levels of continuous 13CO2 enrichment (δ13C +50 or +150‰). At the end of the experiment, we determined dry biomass, C and N concentrations and isotopic compositions for all leaves, buds, twigs, stems and fine and coarse roots for all plants. For all plants, C and N budgets and the amount of newly incorporated C were evaluated.

We found a positive effect of eCO2 on tree growth, with the highest growth response in fine root biomass. In both CO2 treatments, newly fixed C was preferentially allocated to roots compared to other plant compartments, but under eCO2, we found a shift in C allocation patterns towards higher belowground C allocation. These results suggest enhanced plant investments into belowground resource acquisition. Decreased N concentrations in all plant organs of these trees under eCO2 may indicate plant N limitation and suggest that the effect of increased belowground C allocation was insufficient to fulfil the plants N demand. Still, the observed increase in C allocation to microbial biomass in these soils may be a mechanism to enhance plant N nutrition. CO2 concentrations also affected C allocation within the whole plant-soil-system: Under eCO2, more C was stored in tree biomass and less C was stored in soils. Overall, there was no effect of CO2 treatment on total mesocosm C. We will discuss these findings with regard to the N mining hypothesis.
An interactive analysis of users, use and usability of phenological information
Authors: Zurita-Milla Raul , Garcia de Cortazar-Atauri Iñaki , Izquierdo-Verdiguier Emma
Published: March 2020

Phenology is the science that studies the timing of periodic plant and animal life cycle events, as well as their causes, interrelations, and variations in space and time. Phenological information has a plethora of use and hence of users. For example, this information is often used to study climate change because phenological timings respond to changes in environmental conditions. Besides this, phenological information helps to model the water, carbon and energy cycles, is necessary to monitor and manage natural and artificial man-made ecosystems and even supports nature lovers and public health practitioners. The well-established EGU session on “Phenology and seasonality in climate change” shows the diversity of phenological research and products and brings together multiple research communities: ecologists, agronomists, foresters, climatologists, geo-information and remote sensing scientists, and of course, citizen science experts. We believe that this diversity deserves attention and propose carrying out a first analysis of users, use and usability of phenological products by interacting with the participants of this EGU session. For this we will use a presentation software that allows posing questions to the audience and collecting their views in real-time. This presentation will then provide a better view of the phenological community, including their most commonly used data sources, tools, and needs. Special attention will be paid to identify major achievements and research and/or operational gaps that can help to define a phenological agenda for this new decade.
Finding Dynamical Modes of Atmospheric Variability Using Conservation Properties
Authors: Jones Dominic , Methven John , Frame Tom , Berrisford Paul
Published: March 2020

It is evident that persistent large-scale weather phenomena are an important factor in extreme seasonal climate; this has been especially true in boreal summers over the last two decades. Large, relatively slowly changing modes of variability on the mid-latitude jet are key to understanding high impact weather events. High monthly precipitation totals in the summer, for example, are linked to stationary Rossby wave patterns; stationary winter jet patterns can direct North Atlantic cyclones towards the UK and Europe. These wave patterns are often diagnosed but without a link to their phase speeds or dynamics.

To examine these slow modes we define an atmospheric background state as a function of isentropic and materially conserved co-ordinates (potential temperature and PV), resulting in a slowly changing, zonally symmetric background state. We then extract patterns of variability from the set of perturbations by employing an alternative Empirical Orthogonal Function (EOF) technique which utilizes a conserved wave activity as a weighted covariance. This results in statistical (EOF) patterns which possess an intrinsic dynamical phase speed and frequency, which are predicted from the conservation properties pseudomomentum and pseudoenergy. These statistical modes are a recombination of the dynamical normal modes in a system with quasi-linear dynamics.

We examine long runs with relaxation to unstable background jets but without orography, diurnal or seasonal effects, where large amplitude wave activity emerges. These simplified situations are used to test whether or not the predicted phase speeds from theory (given the structures found) matches with the observed phase speeds deduced from the principal component time series of the ENMs. Our hypothesis is that slow wave motion is explained by the structure and conservation properties of the modes. We are able to explore the dependence on the structures by varying the background state.
The role of tides in ocean--ice-shelf interactions in the southwestern Weddell Sea
Authors: Hausmann Ute , Sallée Jean-Baptiste , Jourdain Nicolas , Mathiot Pierre , Rousset Clement , Madec Gurvan , Deshayes Julie , Hattermann Tore
Published: March 2020

A novel regional ocean-sea-ice model configuration is designed to investigate the mechanisms of ocean–ice-shelf-melt interactions in the Weddell Sea. It features explicit resolution of the cavities of eastern Weddell, Larsen and Filchner-Ronne ice-shelves (FRIS, at 1.5-2.5 km horizontal resolution), as well as of the adjacent continental shelves (~2.5 km) and deep open-ocean gyre (at 2.5-4 km), in presence of interannually-varying atmospheric and ocean boundary forcing as well as explicit ocean tides. Simulated circulation, water mass and ice-shelf melt properties compare overall well with available open-ocean and cavity observations, and simulated Weddell ice-shelf melting reveals large variability on tidal, seasonal and year-to-year timescales. The presence of ocean tides, investigated explicitly, is revealed to result in a systematic time-average enhancement of both the production of ice-shelf meltwater as well as its refreezing on ascending branches of especially the FRIS cavity circulation. This tide-driven enhancement of the melt-induced FRIS cavity circulation acts to increase net ice-shelf melting (by 50%, ~50 Gt/yr) and the meltwater export by the FRIS outflow, and modulates their seasonal and lower frequency variability. The tidal impact on ice-shelf melting is consistent with being primarily driven mechanically through enhanced kinetic energy of the time-varying flow in contact with the ice drafts. The dynamically-driven tide-induced melting is thereby to almost 90% compensated by cooling through meltwater produced, but not quickly exported from regions of melting in the Weddell cold-cavity regime. Ocean boundary layer thermal adjustment underneath ice drafts, minimizing departures from the in-situ freezing point, thus substantially dampens the impact of tides on Weddell ocean–ice-shelf interactions. Simulations furthermore suggest attendant changes on the open-ocean continental shelves, characterized by overall freshening and modest year-round sea-ice thickening, as well as a marked freshening of newly-formed bottom waters in the southwestern Weddell Sea.
Characterization of Plastic Pollution in Rivers: Case of Sapang Baho River, Rizal, Philippines
Authors: Diola Ma. Brida Lea D. , Tanchuling Maria Antonia N. , Bonifacio Dawn Rhodette G. , Delos Santos Marian Jave N.
Published: March 2020

Philippines is considered as one of the top contributors of plastic wastes in the oceans globally. Lack of strict implementation of solid waste management regulations has led to mismanaged wastes, especially plastics, that eventually end up in water bodies. This study focuses on characterizing plastic waste pollution in Sapang Baho River in the province of Rizal. The river is located in an urban area and is a significant tributary of Laguna Lake, the largest lake in the country. Through this study, macrowastes and microplastics in Sapang Baho River, Rizal were characterized and analyzed to provide baseline information and to raise awareness to address plastic pollution, in macro- and micro-scale. This study also determined possible sources of microplastics by relating the particles to the plastic wastes present as well as activities in the sites. Waste analysis and characterization studies (WACS) were conducted for four sampling stations along the river. Microplastic samples were also collected from surface water and were characterized based on form such as filament, fragment, film, foam, and pellet through microscope examination. Representative samples were subjected to Raman spectroscopy testing to identify the polymer types. Results show that macrowaste samples were mostly plastic wastes (27.33%) in terms of mass. Plastic wastes were composed of film plastic (47%). Most of the microplastic particles were in the form of filaments (92.24%) which were fragmented from textile wastes and cloth washing. In terms of color, transparent particles were dominant and particles in the lower size range (0.3 mm - 0.8 mm) were predominant. Samples subjected to Raman spectroscopy were mainly polyethylene (PE), a material used in containers and packaging. Lastly, it was calculated that the surface water of Sapang Baho River contributes approximately 24 - 362 microplastic particles to Laguna Lake.
FLOOD SUSCEPTIBILITY in ENDORHEIC AREAS: The case study of Salento peninsula in Apulia (Italy)
Authors: Del Vecchio Michele , Brizzi Sara , De Michele Carlo , Menduni Giovanni , Pedone Maria Antonia
Published: March 2020

The concept of “flood susceptibility” is generally used to identify the flood prone areas. The flood susceptibility defines the probability of a territory to be flooded, and generally is determined according to its geo-litho-morphological and climatic characteristics. Here, we assessed the flood susceptibility in the Apulia region (Southern Italy). This region is characterized by the presence of endorheic basins located in the Salento peninsula. During ordinary rainfall events, these endorheic basins collect all the runoff into karst sinkholes. On the contrary, during severe rainfall events, the runoff saturates the capacity of sinkholes and the further runoff overflows in the lowland. The aim of the work is to characterize properly the flood susceptibility in endorheic areas, which is not adequately investigated at our knowledge.
Lower crustal recycling: Reconciling Petrological and Numerical Constraints from the Pamir
Authors: Stoner Ryan , Behn Mark , Hacker Bradley
Published: March 2020

Geochronological and thermobarometric data from a lower crustal xenolith suite in the Pamir offer a unique record of the transport of lower crust to mantle depths after an episode of slab breakoff. We compare petrologically constrained pressure-temperature-time paths from the xenoliths to pressure-temperature-time (P-T-t) paths of tracked markers in 2-D numerical geodynamic models of density foundering with thermodynamically calculated densities. We investigate whether gravitational “drip” instabilities or the peeling back of a dense layer—delamination—can reproduce the P-T-t paths seen in the xenoliths, with the ancillary goal of capturing the positive feedback between mechanical thickening and densification of the lower crust. Key thermobarometric observations from the xenoliths we try to match in our numerical study are: (1) initial heating at near-constant pressure followed by (2) a sharp increase in pressure with continued heating. We find that thick crustal sections develop P-T-t paths in numerical models of delamination that match the observations from xenoliths: the lower crust initially heats due to return flow from upwelling asthenosphere, and then foundering mantle lithosphere and crust show a marked increase in pressure with additional heating. Initial gravitational drip instabilities founder with relatively little heating yet may thin the mantle lithosphere sufficiently to allow for subsequent delamination or asymmetric drips to nucleate in the region of hotter, thinner mantle lithosphere. Such subsequent asymmetric drips or delamination entrain crust that closely follows the P-T-t path from xenoliths. This suggests that the xenoliths were not derived from an initial drip instability, but instead from later instabilities or delamination enabled by thinning of the lithosphere. In all models where density foundering occurs, the positive feedback between contraction and densification of the lower crust leads to the loss of initially positively buoyant lower crust. The combination of geological and numerical methods constrains the geometry and triggers of lower crustal foundering during collision. Contraction alone does not match the record of foundering; the lithosphere must have also been asymmetrically thinned.

 