bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncertainties in estimating biomass burning emissions for Africa: implications for atmospheric modelling
Authors: Heil Angelika , Bouarar Idir , Brasseur Guy
Published: March 2020

Africa is the biggest continental source of biomass burning emissions. The emissions result in regional to transcontinental air pollution. Atmospheric model studies that address the linkage between fires and air quality have to cope with substantial uncertainties in fire emission inventories. All contemporary fire emission inventories build upon satellite information to quantify the spatial and temporal occurrence of fires, but they use different satellite sensors, detection algorithms, and estimation methods. Large discrepancies between inventories in terms of emission totals and spatial and temporal patterns are the consequence.

Most satellite products employed for fire emission estimations across Africa cannot resolve small fires, and the omission of thereof strongly lowers the accuracy of the estimated emission fluxes. The ESA Fire_cci project has recently released the first burned area product for Africa that builds upon high resolution optical imagery from Sentinel-2. By resolving small fires, it detects 60 to 110% more burned area in 2016 than estimated by the widely used, MODIS-based products GFED4s, GFED4, MCD64A1 Collection 6, FireCCI51 and FINN.

We inter-compare biomass burning emission inventories computed from these products and analyse potential sources of discrepancies. Sensitivity simulations with the WRF-Chem atmospheric chemistry model using the inventories as boundary condition complement the analysis. Modelled concentrations of atmospheric trace species are evaluated against a set of satellite observations that act as top-down constraint on the fire emission estimates.
Using magnetotelluric and seismic geophysical observations to infer viscosity for Glacial Isostatic Adjustment calculations
Authors: Ramirez Florence , Selway Kate , Conrad Clinton
Published: March 2020

A physical property that is important for understanding the geodynamics of Earth’s lithosphere and asthenosphere is the effective viscosity ηeff (the ratio of stress and strain rate). This is particularly important for accurate Glacial Isostatic Adjustment (GIA) calculations, which are increasingly crucial for estimating ice loss and sea level rise from the Greenland and Antarctic ice sheets. Mantle viscosity cannot be measured directly, but can be inferred from strain rate, for example as observed by ground uplift following deglaciation or a seismic event. Empirically, mantle strain rate is mainly controlled by stress, temperature, grain size, and composition (water content and partial melt). The influence of these controlling parameters can be inferred from geophysical observations such as seismic and magnetotelluric (MT) measurements, which are useful for imaging the subsurface of the Earth but do not directly constrain viscosity. These observations can be used to improve constraints on viscosity using a three-step conversion process: (1) constrain temperature from MT, seismic, and other data; (2) constrain compositional structure from MT and seismic data (water content of nominally anhydrous minerals from MT, partial melt content from MT and seismics); and finally, (3) convert the calculated thermal and compositional structures into a constrained viscosity structure. In each conversion process, we can assess and quantify the involved uncertainties. Furthermore, we determine the dominant deformation regime in order to accurately interpret the sensitivity of viscosity to its controlling parameters. For instance, water content strongly affects viscosity for the dislocation-accommodated grain-boundary sliding (dis-GBS) and dislocation creep regimes, while diffusion creep and dis-GBS are highly sensitive to grain size. Stress and grain size are important parameters for determining where these critical transitions may occur. Although neither MT nor seismic velocity observations place strong constraints on grain size, information about seismic attenuation or tectonic history can potentially provide information about grain–size. Overall, we find that seismic and MT observations together can significantly improve estimates of mantle viscosity, and in particular can place useful constraints on the amplitude of regional variations in mantle viscosity. Such constraints will be particularly useful for studies to estimate the impact of such variations on GIA processes.
A study of wildfire risk using environmental indicators
Authors: Wu Shao-Wei , Lin Chao-Yuan
Published: March 2020

The frequently wildfire-prone Dadu Terrace is located on the outskirts of a densely populated city. According to the Taichung Fire Department’s 2013-2017 statistics, there are more than 400 wildfires a year. In particular, hundreds of wildfires occur each month during the dry season, and the mobilization of firefighters will increase the burden of social resources. Wildfire damage and smoke can also endanger protected objects nearby. Combined with the characteristics of agricultural farming, the seasonal variation of NDVI extracted from the satellite images can reflect the land cover category. Wildfires in the Dadu Terrace often accidentally caused by human interference, vegetation change over a short time can be as the factor of artificial interference for analyzing the time-based wildfire frequency. Results show that March to April is the peak period of wildfire occurrence, which consistent with the historic records of wildfire reporting. In addition to the temporal distribution of wildfire occurrence, this study also established a model for estimating the spatial distribution of wildfire risk at the mostly occurring period using the concepts of risk analysis. The model can effectively reflect the distribution of hotspots where wildfires occur, and can be the reference for the relevant authorities on the countermeasures of wildfire disaster prevention and control.

Keywords: Wildfire, Environmental indicators, Risk assessment
SYSTEMLINK - a new project on the effects of stressors across ecosystem barriers
Authors: Girardi Johanna , Schulz Ralf , Bundschuh Mirco , Entling Martin H. , Kröner Eva , Lorke Andreas , Schäfer Ralf B. , Schaumann Gabriele  E. , Schwenk Klaus , Jungkunst Hermann F.
Published: March 2020

The propagation of environmental stressors from water (source) to land (sink) in aquatic-terrestrial meta-ecosystems, has not been intensively investigated. The other way around has been in the focus of linking terrestrial and aquatic domains. To start bridging that gap, SYSTEMLINK, a DFG Research Training Group, addresses the bottom-up and top-down mediated interactions in terrestrial ecosystems, which origin from anthropogenic impairments on aquatic ecosystems. Micropollutants (fungicides and insecticides) as well as invasive species (riparian plants and invertebrates) are considered as crucial forms of multiple stressors in disturbed aquatic ecosystems. SYSTEMLINK will examine the general hypotheses that 1) invasive invertebrates and insecticide exposure and 2) invasive riparian plants and fungicide exposure cause top-down and bottom-up mediated responses in terrestrial ecosystems, respectively. Collaborative experiments in replicated outdoor aquatic-terrestrial mesocosms (site-scale) amended by joint pot experiments (batch-scale), field studies (landscape-scale), and modelling are used to test these general and several more specific hypotheses. The experimental setups will all represent a multi-stress environment and will be derived from the landscape scale. The regular combination of several scales will allow to overcome scale-specific limitations and to ensure both cause-effect quantification and the environmental relevance of the results. Ultimately, SYSTEMLINK thrives to increase our knowledge on effect translation across ecosystem boundaries. By combining biological subsidies and biogeochemical fluxes we will be able to quantify their relative importance. Furthermore, we will closely incorporate the often separated aquatic and terrestrial research areas.
Temporal variations in the surface hydrology across Antarctic ice shelves
Authors: Dell Rebecca , Willis Ian , Arnold Neil , Banwell Alison , Pritchard Hamish , Halberstadt Anna Ruth
Published: March 2020

Widespread surface meltwater systems have been identified across numerous Antarctic ice shelves and have been implicated in their possible instability and eventual breakup. It is crucial to better understand the seasonal and year-to-year development of these surface meltwater systems, which comprise saturated firn (slush) as well as distinct water bodies (lakes and streams). It has been suggested that repeated melting and re-freezing of the surface firn pack over successive years reduces the firn air content, and therefore its porosity, encouraging the formation of surface water bodies over time. Firn air depletion and the formation of surface water bodies may contribute to ice shelf instability, as the ice becomes increasingly susceptible to hydrofracture.

Here, we use Google Earth Engine to investigate the distributions of slush and deeper water bodies across all Antarctic ice shelves known to have surface melt, to quantify how surface meltwater systems evolve both seasonally and over successive summers. To do this, we use supervised classification of Sentinel-2 and Landsat 7/8 imagery to guide the selection of suitable NDWIice thresholds for both the detection of slush and deep surface meltwater. Preliminary results for the George VI Ice Shelf between 2000 and 2017 reveal seasonal patterns in the overall extent of surface meltwater, and the overall meltwater extent typically peaks between January and March each year. The 2009-2010 melt season was characterised by significant melt, and over the course of the melt season the proportion of the overall surface meltwater extent that was held within deep water bodies varied between 0 % (November) and 60 % (January). An increase in the proportion of deep water vs. slush typically aligns with warmer air surface temperatures and, therefore periods of more intense melt.
Local earthquake tomography at the Los Humeros geothermal field, Mexico
Authors: Toledo Tania , Jousset Philippe , Gaucher Emmanuel , Maurer Hansruedi , Krawzcyzk Charlotte , Calò Marco , Figueroa Angel
Published: March 2020

The GEMex* project is a recently finalized European-Mexican collaboration that aimed to improve the understanding of two geothermal fields: Acoculco and Los Humeros Volcanic Complex . These sites are located in the Trans-Mexican Volcanic Belt, a region that hosts numerous active volcanoes and is favorable for geothermal exploitation. Currently, the  Los Humeros Volcanic Complex is one of Mexico’s main geothermal systems with an installed capacity of ~95MW. Many studies have been performed at this site since the 70s highlighting several features and characteristics of the shallow subsurface. However a thorough knowledge of structures and behavior of the system at greater depths is still quite sparse. Hence one main objective of the GEMex project was to conduct several geological, geochemical, and geophysical experiments to investigate deeper structures for future development of local and regional geothermal resources.

In this framework, for the period of one year (September 2017 to September 2018), a seismic array consisting of 45 seismic stations was set to record continuously at the Los Humeros Volcanic Complex. In this study we analyzed the continuous seismic records to detect the micro-seismicity mainly related to exploitation activities. After applying a recursive STA/LTA detection algorithm, we assembled and manually picked P- and S- phases of a catalog of about 500 local events. The detected events were mostly clustered around injection wells, with fewer events located close to known structures. We use the retrieved catalog to derive a new minimum 1D velocity model for the Los Humeros site. We then performed a joint inversion to obtain the 3D Vp and Vp/Vs structures of the geothermal field. A post-processing averaging of several inversions was also computed to increase resolution of the investigated region. In this study we will show the derived Vp and Vp/Vs models for the  Los Humeros Volcanic Complex to emphasize various underground structures and potentially identify possible variations due to changes in temperature, fluid content, and rock porosity.

 

*This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 727550 and the Mexican Energy Sustainability Fund CONACYT-SENER, project 2015-04-68074. We thank the Comisión Federal de Electricidad (CFE) for kindly granting the access to the geothermal field for installation and maintenance of seismic stations.
How hillslopes and channels impact the water age in catchments
Authors: Zarlenga Antonio , Fiori Aldo
Published: March 2020

The water age is a lumped descriptor of the complex dynamics taking place in hillslope and catchments, allowing a synthetic description of mechanisms by which the hillslopes and the channel network transport water and solute at the outlet. Nevertheless, the assessment of the water age is still a challenging problem due to i-technical limitation in the data acquisition and ii- modeling simplification in the data interpretation.

In this study, we present a general physically based framework for the description of the water age in catchments. The water age at the catchment outlet is considered as collection of the different ages of the water particles moving through the outlet at a given time. The water age of each particle results from two main processes: the first one is the transport through the hillslope the second one is the transport thorough the channel. The interplay of those dynamics, which depends on hydrological and geometrical parameters, is of paramount importance in the water age and solute transport study.

Following the previous approach, we develop an analytical framework embedding: i- a Boussinesq model for the description of the flow and the assessment of the water ageing processes in hillslope, and ii- a geomorphological model for the assessment of the water transport and ageing in the channel network.  Besides introducing the model, we provide some relevant examples exploring the impacts of the hillslope and channel dynamics on the water age.
Validation of the CMEMS-IBI wave model with data assimilation in a high resolution regional configuration.
Authors: Ghantous Malek , Aouf Lotfi , Dalphinet Alice , Toledano Cristina , García San Martín Lorea , Barrera Ernesto , Lorente Pablo , García Sotillo Marcos
Published: March 2020

One of the challenges of the Iberia-Biscay-Ireland (IBI) Monitoring Forecasting Centre in CMEMS phase 2 is the implementation of the assimilation of altimeter wave data in the wave forecast system.  In this work we explored the impact of the assimilation of altimeter wave data in the IBI domain.  We ran the Météo France version of the WAM wave model (MFWAM) in the IBI domain for 2018 and 2019, with data assimilated from the Jason 2 and 3, Saral, Cryosat 2 and Sentinel 3 altimeters.  This high-resolution (0.05 degree) configuration was forced by 0.05 degree ECMWF winds, and boundary conditions were provided by a 0.1 degree global model run.  We also included refraction from currents generated with the NEMO-IBI ocean circulation model.  We present results with and without wave–current interactions.  Validation against both buoy data and the HaiYang 2 altimeter shows that the assimilation of data leads to a marked reduction in scatter index and model bias compared to the run without data assimilation; the gains from including currents meanwhile are modest.  

The data assimilation scheme presently implemented in MFWAM uses an optimal interpolation algorithm where constant model and observational errors are assumed.  To add some sophistication, we experimented with non-constant background errors derived from a model ensemble.  Though the effect was small, the method suggests a way to improve the data assimilation performance without substantially altering the algorithm.
An Integrated Food-Energy-Water Systems Model for Tackling Questions Related to Agricultural Produce and Food Supply Chains
Authors: Horvath Arpad , Qin Yuwei
Published: March 2020

The world’s agricultural and food systems vary by climate, geographic region, and local economic development conditions, but trade is making food products global in many cases, which is then followed by global interest in the efficiencies of production, water consumption, energy use, and emissions. Consumers want to know and consider in their decisions the environmental implications of the food they eat, and want to see profound reductions. Farmers and agricultural and food companies want to react positively and make changes, which is a challenge in the face of changing economic, climatic, labor, water, dietary, energy, labor, and emissions considerations and conditions.

Food, energy, and water systems are individually complex and inherently interdependent. Their joint study is both a necessity and a challenge. We have developed an integrated model of food, energy, and water systems to employ all three models simultaneously to tackle complex questions that span all three systems, but also problems that one would only see once the components and parameters of the three systems are in the same framework.

Our model accounts for the various inputs of agricultural production, food processing, and food distribution, from farm to consumer, including water, energy, biocides, labor, capital equipment, productivity, supply chains, transportation, retail and distribution, cooling, food processing, and food and packaging waste. The methodological basis for our model includes life-cycle assessment, life-cycle cost analysis, and a dynamic Bayesian network that allows us to propose optimal solutions in the face of changing conditions.

Through case studies we show what environmental and economic costs are expected to be when evolving water treatment technologies and sources (especially wastewater recycling, stormwater capture, and desalination) and water-saving technologies are deployed in most agricultural production areas of the world to maintain production in the face of climate change and disruptions. Packaging of products holds a key to reducing the environmental impacts of fruits and vegetables. Changing the electricity and energy supply has become an economically feasible opportunity. We incorporate into our model the enormous inefficiencies food waste represents.

The target audience for our model and results includes farmers and agricultural planners in the private and public sectors, individual consumers, water and wastewater agencies and companies, energy companies, food processors, and retail and distribution companies. Our model is globally applicable and scalable.
Process-based hydrological modeling: accounting for subsurface heterogeneity by integrating pedology, geophysics and soil hydrology
Authors: Martini Edoardo , Wollschläger Ute , Bittelli Marco , Tomei Fausto , Werban Ulrike , Zacharias Steffen , Roth Kurt
Published: March 2020

As most hydrological processes are highly nonlinear and controlled by time-varying boundary conditions, numerical models are required for their comprehensive representation. However, one of the major difficulties in vadose zone processes modeling is due to the fact that soils are heterogeneous at all spatial scales. The identification and accurate representation of such heterogeneity can be crucial for quantifying the subsurface hydrological states and water fluxes but it is still a challenge in soil hydrology.

We present an integrated approach for process-based modeling of the vadose zone for a typical hillslope. The approach builds on the integration of classical soil mapping, on accurate monitoring of soil water content as well as on geophysical measurements for characterizing the subsurface heterogeneity. It finally integrates the gathered information into a physical model for simulating the vadose-zone processes with high spatial and temporal resolution.

Starting with a simple soil representation, we present the modeling results for different scenarios of increasing complexity with focus on the discretization and corresponding hydrological parameterization of the soil structures in three dimensions. We highlight and discuss the key challenges that need to be addressed when continuous information about the subsurface heterogeneity is to be mapped in the field and represented in a numerical model.

We argue that linking state-of-the-art experimental methods to advanced numerical tools, and bridging the gap between different disciplines such as pedology, hydrology and geophysics can be the key for improving our ability to measure, predict and better understand the vadose-zone processes. This will provide important knowledge needed for transferring this approach to larger scales where the accurate quantification of the soil water fluxes is required for a more efficient water management in the context of sustainable food production and climate change.
Prospects for oil discovery in the Rhine Rift (Germany)
Authors: Galant Yuri , Pikovskiy Yuri , Čížek Pavel
Published: March 2020

The work was initiated with the aim of assessing the prospects of the Rhine Rift oil potential. The search technique was based on the analysis in basalts of Polycyclic Aromatic Hydrocarbons (PAH) which are an indicator of the oil content of deep horizons. Samples of Rocks were taken from Quarry and Outcrops. PAH analysis was carried out at Moscow State University. All samples contain PAH. 11 components detected. The total amount of the components is 0.052834 mg / kg. Rate of 4 components: Naphthalene and homologous, Phenantren, Difenil, Benz (ghi) perylene is equal more a half of all components (58%). Our study revealed the typical association of PAH, which are characteristic of the oil fields: Phenanthrene, Chrysene, Pyrene, Benz(a)pyren. PAH provide evidence of probable former generation and migration of endogenous hydrocarbons. Existence such components as Phenanthrene, Chrysene, Pyrene, Benz(a)pyren pointed on migrations of Hydrocarbons from depth - (From Oil - deposit?). Samples analyzed show on the existence Hydrocarbons migrations of gases and a more Heavy Hydrocarbons. Favorable geological settings of Rhine Rift, such as seismic activity, new tectonic movements, and presence of Basalt, decompressed rocks of mantle, rift stretching mode, and favorable geochemical indications, such as existence of typomorphic oil-associated PAH (Phenanthrene, Chrysene, Pyrene, Benz(a)pyren), presence the components resembling on compositions of Moravia oil, are positive factors for oil discovery in the Rhine Rift. Data received can serve as base for set detail works for seeking cluster of oil! And in the first instance at areas: Bad Urah, Kaizertuhl-Shellingen.
Detailed Geomorphology of Cold Seeps Associated with a Buried Salt Diapir, Offshore Nova Scotia, Canada
Authors: Campbell Calvin , Normandeau Alexandre , Fraser Paul , MacDonald Adam
Published: March 2020

Cold seeps occur where fluids, such as hydrocarbons, migrate from depth and escape at the seabed. They are relatively common features in petroleum basins around the world. Cold seeps often host unique biological communities and are a potential geological hazard as they can indicate excess pore fluid pressures in shallow sediments. In addition, they can provide critical information about fluid migration pathways and fluid source. This study presents the detailed geomorphology and seismic stratigraphy of recently discovered cold seeps in 2700 metres water depth offshore Nova Scotia, Canada. 

Petroleum industry 3D seismic reflection data, high-resolution single channel G.I. gun and sparker seismic reflection data, Autonomous Underwater Vehicle (AUV) sidescan, swath bathymetry, and sub-bottom profiler data were used to investigate the geomorphology of the cold seep and surrounding seabed. Piston core samples and seabed photography were also acquired in the study area.

The geomorphology in the study area is dominated by the seafloor expression of a salt diapir (L. Triassic to E. Jurassic). Despite being buried by ~1700 m of Cretaceous to Holocene sediment, the diapir forms an oblong mound, 10 km long by 5 km wide that rises 200 m above the surrounding seabed. Two major orthogonal faults are apparent on the seabed that cut the mound along its major and minor axes. Several crestal faults are imaged in the 3D seismic data but do not have a seabed expression. AUV data acquired over the crest of the diapir reveal a 500 m by 200 m fissure on the western flank of the diapir. The fissure is composed of a blocky central zone along its axis, and radiating “cracks” that show backscatter variation, possibly indicating recent fluid expulsion. Integration of the AUV data with the 3D seismic data show that the fissure is fed by a vertical chimney that intersects a bottom simulating reflection above the diapir. Remarkably, the chimney does not appear to be related to any of the sub-vertical crestal faults. Another seep occurs on the eastern flank of the diapir crest and, in contrast, coincides with a crestal fault. There is also evidence for mass wasting down-dip from the fault. Core samples recovered from the second seep contained gas hydrate. In both cases, the cold seeps present as very subtle features on the 3D seismic reflection data and are only positively identified in the AUV datasets. This study shows that conventional surface-acquired acoustic data are potentially insufficient for detecting cold seep morphologies in deep-water settings.
A comparison of OH nightglow volume emission rates as measured by SCIAMACHY and SABER
Authors: Kaufmann Martin , Zhu Yajun , Chen Qiuyu , Xu Jiyao , Gong Qiucheng , Liu Jilin , Wei Daikang , Ern Manfred , Riese Martin
Published: March 2020

Hydroxyl (OH) short-wave infrared emissions arising from OH(4-2, 5-2, 8-5, 9-6) as measured by channel 6 of the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) are used to derive OH concentrations of OH(v=4, 5, 8, and 9) between 80 km and 96 km. Retrieved concentrations are used to simulate integrated radiances at 1.6 um and 2.0 um as measured by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, which are not fully covered by the spectral range of SCIAMACHY. On average, SABER 'unfiltered' data is on the order of 40% (at 1.6 um) and 20% (at 2.0 um) larger than the simulations using SCIAMACHY data. 'Unfiltered' SABER data is a product, which accounts for the shape, width, and transmission of the instrument’s broadband filters, which do not cover the full ro-vibrational bands of the corresponding OH transitions. It is found that the discrepancy between SCIAMACHY and SABER data can be reduced by more than 50%, if the unfiltering process is carried out manually using published SABER interference filter characteristics and latest Einstein coefficients from the HITRAN database. Remaining differences are discussed with regard to model parameter uncertainties and radiometric calibration.
LEWS2020 workshop on regional Landslide Early Warning Systems – experiences, progresses and needs
Authors: Calvello Michele , Devoli Graziella , Freeborough Katy , Gariano Stefano Luigi , Guzzetti Fausto , Reeves Helen J. , Stähli Manfred , LEWS2020 workshop participants the
Published: March 2020

In January 2020, the Istituto di Ricerca per la Protezione Idrogeologica of the Italian National Research Council, the British Geological Survey, the Norwegian Water Resources and Energy Directorate, the Swiss Federal Institute for Forest, Snow and Landscape Research, and the University of Salerno - Italy have organised a 3-day workshop on regional Landslide Early Warning Systems (LEWS). The workshop, held in Perugia, Italy, follows a previous meeting held in Oslo, Norway, in October 2016. The main aims of the initiative are: to collect experiences from worldwide invited experts involved in the design, the development, the operation or the analysis of LEWS, and to exchange knowledge, experiences, challenges and best practices.

The first day of the workshop is dedicated to presentations from identified participants on specific topics relevant for the optimal design, implementation, and operation of global, national and regional LEWS. This is followed by a long discussion session, aimed at addressing many of the issues that are relevant for regional LEWS, including system performance, warning communication and involvement of the stakeholders. The second day is organized around four round tables on the following four topics: (i) data; (ii) landslide forecast models; (iii) warning models; (iv) scope, management structure, stakeholder involvement, and communication. The third day is focused on summarizing and formalizing the main issues discussed in an open document to be later shared with colleagues interested in LEWS.

The final purpose of the workshop is to establish and consolidate a community of experts in LEWS and to build relationships with other communities (e.g., meteorologists, climate scientists, communications scientists). This will help to level up the quality of both theory and practice, and to define standards in early warnings in order to provide timely advisories and to initiate emergency responses to landslides (particularly rainfall-induced) avoiding or reducing life and economic losses. The main outcomes of the workshop, the most debated issues, and the key recommendations included in the open document will be presented and shared.
Influence of maintenance practices on plant community properties interacting with ecosystem functions in an agricultural ditch
Authors: Rudi Gabrielle , Bailly Jean-Stéphane , Caraglio Yves , Dollinger Jeanne , Vinatier Fabrice
Published: March 2020

Maintenance practices restoring the hydraulic capacity of agricultural ditches (mowing, burning, chemical weeding or dredging) modify the plant communities in the short and medium term. However, the medium term modification of plant community composition, parameters and properties, and in turn the associated functions provided by ditches (water transport, propagules and sediment retention, biodiversity conservation) have not attracted much attention so far. Therefore, the main question raised in this study was the following : Do ditch maintenance practices affect plant community composition, parameters, and properties associated with water and particle transport processes (sediments, seeds), as well as biodiversity, in the medium term (two years)?

We designed an experiment to compare the effects of different maintenance practices in a Mediterranean agricultural ditch. We measured the plant richness, morphological parameters and properties of the plant community affecting ecosystem functions twice : before applying the maintenance practices and after two years of contrasting maintenance practices. We assessed the differences between practices using linear models and generalized linear models, followed by pairwise comparisons between means using the Tukey test.

Maintenance practices differently affected plant community composition, parameters and properties, such as richness, proportions of harmful plants, distribution of heights, densities, proportions of growth forms and total biomass. None of the maintenance strategies simultaneously improved the functions considered. After two years, mowing provided the highest alpha-diversity and had a low proportion of harmful plants. Burning was the practice that produced the highest total biomass and blockage factor, and therefore negatively influenced the water transport. However, this practice positively impacted seed retention and sedimentation. Our results suggest that associations of maintenance practices would preserve the trade-offs among the different functions in the medium term.

 
Relationships between vine hydraulics and wine production in Falanghina: morpho-functional and isotopic traceability to evaluate sustainability in a climate change context
Authors: Damiano Nicola , Cirillo Chiara , Battipaglia Giovanna , Amitrano Chiara , Pannico Antonio , Caputo Rosanna , Arena Carmen , Erbaggio Arturo , Cherubini Paolo , Saurer Matthias , Bonfante Antonello , De Micco Veronica
Published: March 2020

In the Mediterranean region, climate change is intensifying the need to improve the resource use efficiency of crops (e.g. water use efficiency) and to increase yield, quality and stability of productions, especially in high profitability and vulnerable crops as grapevine. In a climate change scenario, with increasing temperature and frequency of extreme events, such as prolonged periods of drought, the improvement of knowledge about the plasticity of morpho-functional traits in vines, becomes pivotal. Only a deep knowledge of vine responses to environmental constraints can help achieving the correct management of cultivation factors towards sustainability.

The objective of this study is to apply a multidisciplinary approach for monitoring the resource use efficiency and resource allocation during vine development up to wine production. This general objective will be pursued by analysing the complex relationships between parameters in the continuum environment/plant/wine with specific emphasis on the influence of water availability on the vine, grapes, must and finally wine, in order to relate climate, plant water status and oenological characteristics.

The study was conducted in a vineyard of Vitis vinifera L. subsp. vinifera ‘Falanghina’ located in southern Italy (La Guardiense farm, Guardia Sanframondi, Benevento, Campania region).

The vineyard performance was monitored on the basis of several morphological and eco-physiological parameters, measured in the main phenological phases, including: plant architecture, fertility, leaf anatomical traits, photosynthetic efficiency, leaf gas exchanges, nutritional status, berry and must quality. Water use efficiency was estimated through the analysis of anatomical and stable isotope traits (linked with hydraulic and resource efficiency parameters) from tree-ring series and leaf samples. Stable isotopes were also analysed in the must, in order to check the occurrence of an isotopic signature from the plants towards the must.

The approach proved to be promising for achieving a comprehensive understanding on the impact of environmental constraints not only on plant behaviour, but also on the characteristics of the oenological products, furnishing at the same time a promising tool to reconstruct vine status from the isotopic trace in the must.

 
The influence of the spatial distribution of agricultural conservation practices on hydrological balance variables in a small basin
Authors: Noreika Nina , Dostal Tomas , Li Tailin , Zumr David , Krasa Josef
Published: March 2020

SWAT is perhaps the most widely-used basin-scale hydrological model discussed in modern literature. SWAT is typically used to model large basins (100+ km2) and has even successfully modeled basins at continental scales. Regardless of the typical scale that SWAT is used, SWAT has been shown to adequately model various hydrological processes at smaller scales, but this application is much less common in the literature.  The aim of this study is to utilize SWAT+ in a small (<1 km2) agricultural basin (Nucice) approximately 30 kilometers southeast of Prague, Czechia to determine the effects of various spatial distribution patterns of agricultural conservation practices (no/reduced tillage, crop residues, cover crops, etc.) and their respective impacts on projected runoff, soil water retention, and evapotranspiration.

We were able to successfully calibrate our SWAT+ model for the Nucice experimental catchment from 2014 through part of 2018 using discharge data and estimating ET via remote sensing. After successful calibration, we implemented 4 scenarios to analyze the effects of implementing agricultural conservation practices: 25% continuous in upper 50% of basin, 25% fragmented in upper 50% of basin, 25% continuous in lower 50% of basin, and 25% fragmented in lower 50% of basin.

The adaptation pattern of agricultural conservation practices has significant and disproportionate effects on various hydrological balance parameters. Since it is rare that a single farmer manages an entire basin, this study shows that widespread adaptation of agricultural practices is necessary to maximize water conservation within a landscape. We intend to upscale this study (100+ km2 basins) and to compare basins across multiple climates to determine if these effects are universal.

This research has been supported by project H2020 No. 773903 Shui, focused on water scarcity in European and Chinese cropping systems.
Tracing the sources of organic matter in the Seine Estuary (NW France) using bulk and molecular analyses
Authors: Huguet Arnaud , Thibault Alexandre , Anquetil Christelle , Derenne Sylvie
Published: March 2020

Estuaries are key ecosystems from economical and ecological points of view. This is especially true for the Seine Estuary, its watershed representing 12% of the France area (78 600 km2) in which 30% of the French population, 40% of the industry and 25% of the agriculture are concentrated. Estuaries transfer material from the continent to the oceans, including organic matter (OM), for which they are highly reactive zones. Elucidating the estuarine OM dynamics remains challenging, due to (i) the high variability of environmental parameters, such as salinity, light penetration and tidal range, (ii) the intrinsic heterogeneity and molecular diversity of OM and (iii) the permanently changing nature of this material. Estuarine OM can originate from various sources (transported from rivers or coastal ocean or be produced within the estuary itself) with a different composition, and thus a different behaviour in the ecosystem.

The aim of this work was to better constrain the sources of OM in the Seine Estuary. In order to take into account the spatiotemporal variability of OM characteristics, water and sediment samples (10 cm-long cores) were collected all along the estuary, i.e. in the upstream, maximum turbidity and downstream zones, during 5 campaigns with different tidal intensities and river flows. Elemental (C, N) and isotopic composition (δ13C and δ15N) as well as lipid biomarkers were analyzed in both particulate (POM) and sediment OM. This allows comparing the bulk and molecular composition as well as sources of OM in the particulate and sediment pools.

Several lipid biomarkers (n-alkanes, fatty acids, n-alcohols, sterols/stanols, GDGTs) were investigated in this study, as they provide complementary information of the sources and degradation degree of OM. Lipids from terrigenous sources were predominant in all samples, even though the concentrations of these compounds as well as those of anthropogenic origin were shown to decrease towards the mouth of the Seine Estuary. In addition, significant differences in bulk and molecular composition were observed between the particulate and sediment pool, especially with a higher abundance of aquatic (i.e. algal/bacterial) vs. terrigenous lipids in POM than sediment OM. Last, bulk and molecular analyses both showed the strong seasonal and spatial variability (along the estuary and with depth) of OM composition in the water column and sediment, which has to be taken into account when investigating estuarine OM dynamics.
Variability in Rainfall and Kinetic Energy across scales of measurement: evaluation using disdrometers in Paris region
Authors: Jose Jerry , Gires Auguste , Schertzer Daniel , Roustan Yelva , Ruas Anne , Tchiguirinskaia Ioulia
Published: March 2020

To calculate the effect of rainfall in detaching particles and initiating soil erosion, it is important to represent relationship between recorded drop size distributions (DSD) and fall velocity across various scales of measurement. Commonly used relationships between kinetic energy (KE) and rainfall rate (R) exhibit strong dependence on the temporal resolution at which analysis is carried out. Here we aim at developing a scale invariant relationship relying on the framework of Universal Multifractals (UM), which has been widely used to analyze and characterize geophysical fields that exhibit extreme variability over measurement scales.

Rainfall data is collected using three optical disdrometers working on different underlying technologies (one Campbell Scientific PWS100 and two OTT Parsivel2 instruments) and operated by Hydrology, Meteorology, and Complexity laboratory of École des Ponts ParisTech in the Paris area (France). They provide access to the size and velocity of drops falling through sampling areas of few tens of cm2. Such data enables estimation of rainfall microphysics, R and KE at various resolutions. The temporal variation of this geophysical data over wide range of scales is then characterized in the UM framework. A power law relation has been developed for describing the dependence of KE on R. The developed equation using scale invariant features of UM are valid not only at a single scale, but also across scales. The amount of uncertainty is further characterized by comparing actual data with simulated rainfall data from Sense-City climate chamber.

Keywords: rainfall intensity; rainfall kinetic energy; disdrometer; multi fractal; scale invariant
Stratigraphic and mineralogical characteristics of the Fishtie Cu-Co deposit in Zambia
Authors: Tsuruoka Subaru , Hitzman Murray
Published: March 2020

The Central African Copper Belt of southern Democratic Republic of Congo (DRC) and northern Zambia is one of the world’s major sources of metals and currently accounts for world ~48% of cobalt reserves which will be critical for the shift to a low-carbon economy. The Cu-Co deposits are hosted in the Neoproterozoic Katangan Supergroup. The Fishtie Cu-Co deposit is located in the Lusale basin, to the southeast of the Zambian Copperbelt. At Fishtie, the Grand Conglomerate, which is interpreted as a Sturtian-age glacial diamictite, directly overlies basement schist and quartzite. Cu-Co sulphides are hosted in both the Grand Conglomerate and overlying Kakontwe Dolomite. The current study aims to refine the geological and genetic model of the deposit and is based on detailed logging of 41 cores totalling 8,040m including newly collared exploration drill holes.

The Grand Conglomerate (Mwale Formation) is comprised of several lithofacies but can be broadly classified into two lithofacies including diamictite and siltstone. The upper contact of the Grand Conglomerate is commonly gradational with increasing dolomite contents from bedded siltstone to bedded dolomitic siltstone into the lowermost bedded silty dolomite of the overlying Kakontwe Dolomite. Kakontwe Dolomite at Fishtie is subdivided into four lithofacies: bedded silty dolostone, massive dolostone, bedded dolomitic siltstone and laminated dolostone. Inidividual lithofacies display significant thickness variations that appear to be related to syn-sedimentary fault movement.

Hypogene chalcopyrite and bornite occur as disseminations in siltstones within both the Grand Conglomerate and Kakontwe Dolomite. Sulphides are most abundant in coarser-grained beds. The bedded dolomitic siltstone of Kakotwe Dolomite was also locally significantly mineralized. The bedded silty dolostone, massive dolostone and laminated dolostone facies of the Kakontwe Dolomite were poorly mineralized. Up to several percent hypogene cobalt mineralization is recognized in the eastern part of the deposit. Current data suggests that cobalt content was not controlled by either lithology. Hypogene Cu-Co sulphides are related to the location of syn-sedimentary faults. Work is ongoing regarding the deportment and paragenesis of cobalt in the deposit.
Denoising Swarm Geomagnetic Virtual Observatories using principal component analysis
Authors: Cox Grace , Brown Will , Beggan Ciaran , Hammer Magnus , Finlay Chris
Published: March 2020

Geomagnetic Virtual Observatories (GVOs) use satellite measurements to provide estimates of the mean internally-generated magnetic field (MF) over a specified period (usually one or four months) at a fixed location in space, mimicking the mean values obtained at ground-based observatories (GOs). These permit secular variation (SV) estimates anywhere on the globe, thereby mitigating the effects of uneven GO coverage. Current GVO estimates suffer from two key contamination sources: first, local time sampling biases due to satellite orbital dynamics, and second, MFs generated in regions external to the Earth such as the magnetosphere and ionosphere. Current methods to alleviate this contamination have drawbacks:Averaging over four months removes the local time sampling bias at the cost of reduced temporal resolution

Stringent data selection criteria such as night-time, quiet-time only data greatly reduce, but do not entirely remove, external MF contamination and result in a small subset (<5%) of the available data being used

Removing model predictions for external MFs from the measurements also reduces noise, however such parameterisations cannot fully describe these physical systems and some of their signal remains in the data.

Here we present an alternative approach to denoising GVOs that uses principal component analysis (PCA). This method retains monthly resolution, uses all available vector satellite data and removes contamination from orbital effects and external MFs. We present an application of PCA, implemented in an open-source Python package called MagPySV, to new GVOs calculated as part of a Swarm DISC project.  The denoised data will be incorporated into a new GVO data set that will be available to the geomagnetism community as an official Swarm product.  