bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismic velocity changes in the epicentral area of the Mw 7.8 Pedernales (Ecuador) earthquake from cross-correlation of ambient seismic noise
Authors: Agurto-Detzel Hans , Rivet Diane , Charvis Philippe
Published: March 2020

In the last decade, correlation of ambient seismic noise has opened a window to new possibilities for the study of structural properties of the Earth. One such possibility is the monitoring of transient changes in the mechanical properties of the surrounding crustal material following an earthquake. These changes, expressed as variations in seismic velocities, are usually associated to fracture damage and release of fluids due to the earthquakes shaking, but could also be related to deformation associated with afterslip. On April 16, 2016, a Mw 7.8 earthquake struck the coast of Ecuador, rupturing a ~100 km-long segment of the megathrust interface previously identified as highly coupled. Shortly after the mainshock, we deployed a temporary seismic network to monitor the post-seismic phase, in addition to the already in-place permanent Ecuadorian network. Here we present results from cross-correlation of continuous ambient seismic noise during a ~12-months period following the mainshock. Taking advantage of the dense and extensive station network, we investigate the spatio-temporal evolution of the post-seimic seismic velocity changes. Our results show a slow but sustained increase in the average seismic velocities after the earthquake, with a decay in the rate of the increase during the last few months. Spatially, the increase is more notorious nearby the rupture area, whereas the amplitude of the increase diminishes as we move away from the epicenter. We interpret these variations in seismic velocities (steady increase) as the crust’s response to the healing process that takes place during the post-seismic phase, following the sudden coseismic decrease of seismic velocities during the mainshock. This healing process could involve the decrease of fluid-related pore pressures and the healing of fractures and cracks generated during the mainshock, both at the interface and on the overriding plate.
Automatic calcareous nannofossil biostratigraphy using the latest version of SYRACO
Authors: Beaufort Luc , Gally Yves , de Garidel-Thoron Thibault , Marchant Ross , Tetard Martin
Published: March 2020

SYRACO (SYstème de Reconnaissance Automatique de COccolithes) is a software that pilots an automatic microscope and a digital camera in order to automatically recognize coccolith species and measure their morphological characteristic based on artificial neural networks. The first version was displayed in 1996 (Dollfus and Beaufort, 1996; 1999) and was scientifically used for the first time in 2001 (Beaufort et al., 2001). SYRACO evolved during the last 20 years in many aspects such as the architecture of the neural networks, the image scanning and pre-treatments. Twenty years ago, SYRACO was dedicated to quaternary paleoceanographic studies, because it was able to recognize morphological classes. With all the developments, it is now able to be used in biostratigraphy as it is able to determine coccolith species. The latest version of SYRACO will be described, and an example of application to a south Pacific core will be given.  

 

Beaufort, L., de Garidel Thoron , T., Mix, A. C., and Pisias, N. G.: ENSO-like forcing on Oceanic Primary Production during the late Pleistocene, Science, 293, 2440-2444, 2001.

Dollfus, D., and Beaufort, L.: Automatic pattern recognition of calcareous nannoplankton, Neural Network and their Applications : NEURAP 96, Marseille, France, 1996, 306-311, 

Dollfus, D., and Beaufort, L.: Fat neural network for recognition of position-normalised objects, Neural Networks, 12, 553-560, 1999.
A machine learning approach for faster and more accurate precipitation retrievals
Authors: Eriksson Patrick , Pfreundschuh Simon , Norrestad Teo , Kummerow Christian
Published: March 2020

A novel method for the estimation of surface precipitation using passive observations from the GPM constellation is proposed. The method, which makes use of quantile regression neural networks (QRNNs), is shown to provide a more accurate representation of retrieval uncertainties, high processing speed and simplifies the integration of ancillary data into the retrieval. With that, it overcomes limitations of traditionally used methods, such as Monte Carlo integration as well as standard usage of machine learning.

The bulk of precipitation estimates provided by the Global Precipitation Measurement mission (GPM) is based on passive microwave observations. These data are produced by the GPROF algorithm, which applies a Bayesian approach denoted as Monte Carlo integration (MCI). In this work, we investigate the potential of using QRNNs as an alternative to MCI by assessing the performance of both methods using identical input databases.

The methods agree well regarding point estimates, but QRNN provides better estimates of the retrieval uncertainty at the same time as reducing processing times by an order of magnitude. As QRNN gives more precise uncertainty estimates than MCI, it gives an improved basis for further processing of the data, such as identification of extreme precipitation and areal integration.

Results so far indicate that a single network can handle all data from a sensor, which is in contrast to MCI where observations over oceans and different land types have to be treated separately. Moreover, the flexibility of the machine-learning approach opens up opportunities for further improvements of the retrieval: ancillary information can be easily incorporated and QRNN can be applied on multiple footprints, to make better use of spatial information. The effects of these improvements are investigated on independent validation data from ground-based precipitation radars.

QRNN is here shown to be a highly interesting alternative for GPROF, but being a general approach it should be of equally high interest for other precipitation and clouds retrievals.
EUMETSAT Copernicus Marine Training and User Support
Authors: Evers-King Hayley , Traeger-Chatterjee Christine , Wannop Sally , Biermann Lauren , Clements Oliver
Published: March 2020

EUMETSAT provides user support and training for all users of the Copernicus Marine Data Stream (CMDS). The CMDS refers to all the level 1 and level 2 marine data from sensors on the Sentinel-3 and Jason-3 satellites, including ocean colour, sea surface temperature, and surface topography data. Details on the products and processing methodologies are available through handbooks, product notices, and a number of services including a help desk, and online forum. The training service aims to support all users wishing to explore potential applications of the CMDS. The service is primarily based around the delivery of two week, blended courses with both an online and classroom component.  The online component is hosted on a Moodle platform and uses a variety of prepared resources including short articles, videos, software installation, and basic software tutorials; supported by discussion forums, to prepare participants for the classroom phase. The classroom phase is focused on practical work, with no lectures given. Participants are led through examples of workflows using SNAP and Jupyter Notebooks/Python, and are then given one-on-one/small group trainer support to work for 3 days on personal projects that they defined during the online phase. These projects yield a diverse range of synergistic use cases of ocean remote sensing data for societally relevant applications The training service has also run a variety of collaborative courses with community led initiatives, and proposes to develop online courses and resources in response to community needs. Feedback and requests from the ocean remote sensing community are welcomed.

 
Near-surface structure revealed by ground penetrating radar profiling across an inland active fault ruptured one month after the 2011 Tohoku-oki earthquake, southern Fukushima, NE Japan
Authors: Kimura Haruo , Tsutsumi Hiroyuki , Higashimaru Naotsugu , Taniguchi Kaoru
Published: March 2020

  The 11 March 2011 Tohoku-oki earthquake (Mw = 9.0) ruptured a 500 km-long and 200 km-wide thrust of convergent boundary between the North American and Pacific plates. The earthquake caused crustal stress field changes and triggered widespread seismic activity in the northeast Japan. The southern Fukushima area was struck by many earthquakes. The largest normal faulting (Mw = 6.6) in the area ruptured the NW-trending Yunodake fault and the NNW-trending Itozawa fault on 11 April 2011. The coseismic surface ruptures were observed along active and presumed active faults identified previously. To investigate the near-surface structure of the Itozawa fault, we conducted ground penetrating radar (GPR) profiling across the fault, and we carried out two drilling surveys in hanging and foot walls of the fault. The survey line, which length was about 50 m, was located nearby a trench site (Toda and Tsutsumi, 2013). The GPR data were collected by common-offset modes using 50, 100, and 200 MHz GPR systems (pulseEKKO PRO made by Sensors and Software Inc.), and the station spacing was 0.05 m. Furthermore, we carried out wide-angle measurements, and acquired common mid-point (CMP) ensembles at the both sides of the surface rupture to estimate the electromagnetic wave velocity used in the depth conversion of the GPR sections. The GPR sections after careful data processing show detailed structure above a depth of about 10 m. We interpreted some horizons as an event showing coseismic deformation on 11 April 2011, the past seismic event reported by Toda and Tsutsumi (2013), that informing the former event, respectively. The horizons explain accumulation of vertical displacement on the Itozawa fault.

 
STXM analysis of fungal soil aggregation
Authors: Hammer Edith C. , Persson Per , Pucetaite Milda
Published: March 2020

Understanding soil’s C sink potential is crucial to support soil management that increases its long-term carbon storage. Soil aggregate formation is known to be a main factor for long-term C sequestration, as C becomes physically protected, or “hidden”, within an increasingly complex three-dimensional structure.

The dynamic process of soil aggregation is however not yet clearly understood. Soil (micro) organisms are thought to play a decisive role in “gluing together” and redistributing particles. They also move existing organic material, and include own exudates and dead cells into aggregates. Fungi, and especially mycorrhizal fungi play a key role in physical organic matter stabilization as they transport carbon compounds over long distances and into narrow soil pores, but little is known about the chemical remnants they leave to soil aggregates.

We investigated the exudates of single hyphae of two saprotrophic and two mycorrhizal fungi (G. confluens, P. subvisciva, P. involutus, R. irregularis), with and without contact to three types of minerals (quarts, goethite, muscovite). We grew them in sterile cultures on Si3N4 windows and analysed hyphae, their exudate layers and the organo-mineral interfaces. STXM analysis was performed at CLS, Canada, Diamond, UK, at the C(K), K(L), N(K) and Fe(L) absorption edges, and we made complementary measurements with photothermal IR microspectroscopy at Soleil, France. We found differential composition of the exudates depending on fungal species and environmental conditions. In some cases, we could identify spatially resolved oscillating plumes of K exudates emitted from the hyphae, indicating possible exudation channels. Goethite particles in close vicinity to a hypha showed reduced Fe(2+) compounds, suggesting that oxidative processes may take place. We further investigated thin-polished samples of AMF hyphae grown in a sterile soil, and located polysaccharide-, lipid- and protein-compounds in the surrounding soil matrix.

 

Our results will help to better understand the processes of fungal soil aggregation and physical organic matter stabilization.
Cluster analysis of organic molecules in an alpine ice core: the transition from the pre-industrial to the industrial era
Authors: Bachmeier Franziska , Vogel Alexander L. , Lauer Anja , Fang Ling , Arturi Katarzyna , Baltensperger Urs , Bjelić Saša , El Haddad Imad , Schwikowski Margit
Published: March 2020

The effects of atmospheric aerosol particles on the Earth’s radiative balance are a major source of uncertainty in global climate models. A distinction and quantification between natural and anthropogenic atmospheric aerosol concentration and their sources has to be made to reduce this uncertainty. Therefore, the natural pre-industrial aerosol concentration of the atmosphere must be determined. Ice cores are climate archives that enable the reconstruction of past atmospheric composition changes.

For such a reconstruction, an ice core from the Swiss Alps, which covers the years from 1682-1985, was examined for secondary organic aerosol (SOA) compounds. A non-target analysis (NTA) was used to determine the chemical composition of small organic molecules in the ice. The analytical method of the melted ice samples is based on solid-phase extraction, liquid chromatography and high-resolution mass spectrometry. The result of the NTA showed more than 630 features statistically different from the blank. A hierarchical cluster analysis was performed, in which compounds with a similar trend over time were grouped (clustered) together. The cluster analysis separated the considered features into two main groups. The first cluster showed a good correlation with the dissolved organic carbon concentration (DOC) of non-fossil origin (R = 0.75) while the second main group correlated excellently with the fossil DOC (R = 0.95), attributed based on the radiocarbon content. This leads to the presumption that compounds represented in the first cluster originated from biogenic sources while compounds in the second cluster are anthropogenic emissions or SOA formed by anthropogenically emitted precursors. This hypothesis is supported by the temporal trend of the two groups. The potential biogenic compounds show a relative stable behavior throughout time.  At the beginning of the 20th century a decrease of biogenic SOA is recorded. No compounds from the anthropogenic cluster were detected in pre-industrial times, they increase slowly from 1800 and more and more from 1900. Based on the division into the two main clusters, a detailed graphical evaluation of their chemical composition was performed. We show that the suspected biogenic cluster consists mainly of oxidation products of volatile organic compounds (VOC). The presumed anthropogenic cluster consists mainly of organosulfates, nitrooxy-organosulfate, aromatic compounds and mono- and dinitroaromatics.
High-resolution inversion of methane fluxes using in-situ and satellite measurements over Africa
Authors: Abdi Amir Hossein , Marshall Julia , Rodenbeck Christian , Koch Frank-Thomas , Gerbig Christoph
Published: March 2020

Due to the growth of atmospheric methane and the remarkable uncertainties in its budget, there is a need to constrain the sources and sinks of this atmospheric tracer. Among the different regions emitting methane to the atmosphere, Africa has a considerable contribution to the global methane budget and has one of the largest associated uncertainties. Surface-based measurements could help to substantially diminish these uncertainties, but given the dearth of in-situ observations in most areas of Africa, satellite retrievals can be helpful to fill this gap. We use ground-based observations along with the SRON’s proxy and full physics XCH4 products from the Greenhouse Gases Observing Satellite (GOSAT), and an inversion system consisting of the global 3-dimensional transport model TM3 as well as the high-resolution regional Stochastic Time-Inverted Lagrangian Transport model STILT to spatially resolve the regional emissions in Africa with a focus on the natural wetlands and also the oil and gas industries in Nigeria and Angola as the top oil-producing African countries. In this study, the global inversion is performed for 2009-2015 on a coarse resolution, ~ 3.83˚ x 5˚. The nominal spatial resolution of the regional inversion is 0.25˚ x 0.25˚ for 2011-2012. Prior fluxes for the nested run include the Emission Database for Global Atmospheric Research (EDGARv4.3.2) for anthropogenic sources including agriculture, and waste and energy, WetCHARTs wetlands ensemble, the Global Fire Assimilation System (GFAS) for biomass burning, Sanderson’s global database of termite methane emissions, and the soil Methanotrophy Model (MeMo) for the methane soil uptake. The significance of the petroleum industries’ emissions is examined by high-resolution inversions. Additionally, the consistency of the optimised fluxed derived from different types of measurements (e.g. surface-only, surface+satellite, satellite-only) is investigated and discussed.
Dimethylmercury demethylation in the presence of sulfide
Authors: West Johannes , Graham Andrew , Nguyen Liem , Jonsson Sofi
Published: March 2020

In marine systems, the methylated mercury pool is approximately evenly distributed between monomethylmercury (MMHg) and dimethylmercury (DMHg). While MMHg is well-studied due to its direct link with Hg accumulation in aquatic food webs, there is a general lack of knowledge of processes controlling DMHg formation or degradation. By acting as a net sink or source for MMHg, DMHg may exert control over marine MMHg concentrations and subsequent Hg bioaccumulation in fish and seafood in ways currently not understood. 

At present, recognized degradation pathways of DMHg in marine systems include photochemical demethylation (although this pathway has been debated). Degradation through protonolysis of the Hg-C bond by dissolved sulfide has also been suggested and supported by density function theory calculations (Ni et al, J. Phys. Chem. A, 2006). However, experimental support for this pathway is currently missing. Here, we present data from a series of experiments for the stability of DMHg in the presence of dissolved sulfide or sulfide minerals (e.g. FeS (s)). Our results show that degradation rates are dependent on the sulfide phase and DMHg:sulfide ratios. For dissolved sulfide, we observed a non-linear response between DMHg degradation and sulfide concentrations. Our results indicate that DMHg can be demethylated by sulfide at concentration ratios viable under natural marine conditions. As we found MMHg to be the first product of demethylation, this process could also constitute a significant MMHg source in marine systems.
Evaluating travel time distributions of macroporous hillslope
Authors: Dusek Jaromir , Vogel Tomas
Published: March 2020

Residence and travel times of water in headwater catchments and hillslopes represent important descriptors of hydrological regime. In this study, travel time distributions were evaluated for a montane forest hillslope site using a two-dimensional dual-continuum model. The model was used to simulate the seasonal soil water regime and selected major rainfall–runoff events observed at the hillslope site. In particular, it was used to generate hillslope breakthrough curves of a fictitious conservative tracer applied at the hillslope surface in the form of the Dirac impulse. The simulated tracer breakthroughs allowed us to estimate the travel time distributions of soil water associated with the episodic subsurface stormflow, deep percolation and transpiration, yielding partial travel time distributions for the individual discharge processes. The travel time distributions determined for stormflow were dominated by the lateral component of preferential flow. The event-based stormflow median travel times ranged from 1 to 17 days. The estimated travel times were significantly affected by the temporal rainfall patterns and antecedent soil moisture distributions. The applied modeling methodology can be used for the evaluation of runoff dynamics at the hillslope and catchment scales as well as for the quantification of biogeochemical transformations of dissolved chemicals.
When mobilized organic matter and glacial suspended sediment meet: effects of adsorption, photo- and biodegradation
Authors: Groeneveld Marloes , Jakobsson Elizabeth , Hawkes Jeffrey , Tittel Jörg , Kothawala Dolly , Tranvik Lars
Published: March 2020

The thawing of permafrost is leading to increased export of organic matter into aquatic ecosystems that was previously stored within frozen peatland soils. This organic matter has been found to be reactive to microbial and photochemical processes, so that permafrost thaw is expected to lead to an increased production of greenhouse gases. Being able to predict the fate of these increased loads of terrestrial organic carbon in aquatic systems is therefore important from a climate change perspective. In a previous study we suggest that terrestrial organic compounds susceptible to photodegradation are also prone to adsorb to mineral particles. Whereas photodegradation stimulates CO2 production, adsorption has the potential to remove organic matter from the water column and store it in the sediment. Warming at high latitudes involves both permafrost thaw and glacial melt. Glacial runoff streams often contain high loads of suspended sediment. As these minerogenic particles are transported downstream the aquatic continuum, they can eventually mix with water containing high concentrations of freshly released organic matter, and act as an adsorbent.

In order to predict CO2 production from mobilized permafrost organic matter, we need to study the bioavailability of this material before and after alteration by physical and chemical processes such as photodegradation and adsorption to mineral particles. In this study, we compared the effect of adsorption to glacial suspended sediment to that of photodegradation on the dissolved organic matter composition of surface water collected from a thawing peat plateau in northern Sweden. We used optical measurements and mass spectrometry to evaluate changes in the composition of the organic matter and employed a three-month incubation to determine its bioavailability. Initial results from optical measurements indicate that while chromophoric compounds in general were removed by both photodegradation and adsorption, humic-like fluorescent compounds were more susceptible to photodegradation than adsorption. UV-irradiation increased bioavailability of the organic matter, whereas pre-treatment by adsorption to mineral particles slightly decreased bioavailability compared to the control. Results from this study will help advance our understanding of interactive effects between physico-chemical processes and microbial degradation at an increasingly relevant interface where melting permafrost meets glacial meltwaters.
The influence of grain size and frictional/cohesional shear strength components on UK salt marsh substrate stability
Authors: Brooks Helen , Moeller Iris , Spencer Tom , Royse Kate
Published: March 2020

Salt marshes attenuate waves and currents, thus protecting landward-lying constructed defences and the hinterland from incoming waves and extreme water levels. As such, understanding the stability of the marsh sedimentary platform is important, particularly as marsh edge erosion is common on many shores. To understand why marshes are losing material from their exposed fringes, we must better understand the relations between the marsh fabric and incoming hydrodynamic energy; this is likely to be strongly influenced by marsh biological, geochemical and sedimentological/geotechnical properties. Currently there is little systematic research into the within- and between-marsh variability in these properties and how they affect both marsh edge and marsh surface erosion processes.

 

We compare Tillingham marsh, eastern England, where the sediment is clay/silt-dominated and the marsh canopy is species-rich, to Warton marsh, Morecambe Bay, NW England, where the sediment is sand/silt-dominated and the vegetation species-poor. We determine soil shear strength by applying geotechnical methods which, to the best of our knowledge, have not previously been applied to salt marsh environments. Shear box and ring shear tests are used to determine the natural- and residual (i.e. post-failure) shear strength of the substrate, respectively. This is expressed as the cohesion of the sediment and the angle of internal friction. We demonstrate that the ring shear test consistently returns a lower angle of internal friction for the substrate, which is expected for the residual angle of internal friction. However, we are also able to link this reduction in the angle of internal friction to substrate composition (e.g. root content, organic matter and particle size distribution). This enhanced methodological understanding will improve our comprehension of marsh resistance to edge erosion and thus our ability to predict future erosion. Ultimately, accurate measurements of the shear strength of natural foreshores are essential for the informed implementation of nature-based coastal flood defences, including ‘de-embankment’/‘managed realignment’ schemes.
Microbial life in collapsing permafrost in NE Greenland
Authors: Scheel Maria , Christensen Torben R. , Rundgren Mats , Suhr Jacobsen Carsten , Zervas Athanasios
Published: March 2020

In recent years, permafrost-affected soils have been shown to be gradually subject of thawing (IPCC, 2019). Formerly frozen soil organic carbon stocks hence become increasingly susceptible to microbial decomposition and transformation into greenhouse gases (Schuur et al., 2015). An estimated 20% of Arctic permafrost areas are subject of melting of belowground ice and consequent collapse (Olefeldt et al. 2016), but these thermokarst landscapes are often difficult to assess.

In 2018, a thermokarst developed into a thermal erosion gully in close vicinity to the Zackenberg Research Station. As one of the main stations of the Greenland Ecosystem Monitoring (GEM) program, the monitoring of various ecosystem parameters at this site during the past 25 years, including hydrology, soil temperature and active layer depth, enables a spatiotemporally precise description of the thermokarst's physical progression.

In order to characterize the development of a thermokarst soil microbial community and understand its spatial distribution and taxonomic biodiversity, soil cores of 30 cm above and below an ice lens were extracted in August 2018, as well as after a dry and warm summer season in September 2019, until 90 cm depth to also sample still frozen permafrost soils. Soil characterization included loss on ignition, radiocarbon dating and microbial viability assays for both years. Bacterial 16S rDNA V3-V4 and fungal ITS1 gene region amplicons of extracted DNA were sequenced and analyzed. With the microbiome involved in biochemical processes such as nitrogen fixation, methane production and oxidation as well as CO2 respiration, knowledge about abundance, genetic and adaptation potential of bacteria, archaea and microeukaryotes in fast changing permafrost soils affects several ecosystem carbon fluxes significantly.

This work is part of a project, describing both the taxonomic and functional composition of this thermokarst microbiome, including the use of multi-omics to reveal the carbon cycling gene potential and expression in combination with in situ and laboratory incubation gas fluxes of CO2, N2O and CH4. These biological and biogeochemical insights from this event are put into perspective with long-term, maintained data supplied by the GEM. 
Rescue of Ukrainian early historical climatological data
Authors: Boichuk Dmytro , Luterbacher Jürg , Allan Rob , Skrynyk Olesya , Sidenko Vladyslav , Palarz Angelika , Oshurok Dmytro , Xoplaki Elena , Skrynyk Oleg , Osadchyi Volodymyr
Published: March 2020

Modern climate applications and climate services are seeing the need for more data and information (including its historical part) on climate variability at high temporal and spatial resolution. Therefore, daily or even sub-daily meteorological data are required increasingly to feel this gap and provide the basis for climate research, extreme events analysis and impact studies.

The main objective of our work is to present information on results of data rescue (DARE) activity conducted recently in the Ukrainian Hydrometeorological Institute (UHMI, Kyiv, Ukraine) in close collaboration with several national and international partners. Our DARE activity was concentrated mainly on the original sub-daily, pre-1850 meteorological observations conducted at eight meteorological stations located in the territory of modern Ukraine, namely Kyiv, Kharkiv, Poltava, Kamyanets-Podilsky, Lugansk, Dnipro, Kherson and Odesa. These eight stations are the only ones, whose pre-1850 data have been found in an archive of the Central Geophysical Observatory (CGO), an observation institution of the Ukrainian Weather Service.

The data are contained in 38 special hard copy books. Before digitization, the book pages were photocopied to create a database of the images of all the paper sources. Its two copy versions are now stored at the UHMI and CGO, respectively. After the creation of the images database, the data were digitized manually by the authors. In total 291 103 values were digitized. These include 165 980 air temperature records (~57% of the total), 124 376 atmospheric pressure measurements (~42.7%) and 747 precipitation totals (~0.3%).

Quality control of the digitized data was conducted, including intercomparisons between the stations as well as comparisons with monthly temperature data that were digitized previously from other sources. The quality control procedures revealed a fairly good agreement among the rescued time series on the monthly time scale as well as a good accordance with the monthly data from other sources. However, several periods at some stations should be used with caution, due to relatively large discrepancies revealed. The rescued digital dataset can be used for different meteorological and climatological purposes, including the analysis of extreme events for the pre-1850 period in comparison with today’s climate, regional climatological studies, etc. The dataset is an important supplement to existing digitized archives of meteorological measurements that were performed in the first half of the 19th century.
Planetary Science Virtual Observatory: VESPA/Europlanet outcome and prospects
Authors: Erard Stéphane , Cecconi Baptiste , Le Sidaner Pierre , Rossi Angelo Pio , Rothkaehl Hanna , Capria Teresa
Published: March 2020

The Europlanet-2020 programme, which ended Aug 2019, included an activity called VESPA (Virtual European Solar and Planetary Access) which focused on adapting Virtual Observatory (VO) techniques to handle Planetary Science data. We will present some aspects of VESPA at the end of this 4-years development phase and at the onset of the newly selected Europlanet-2024 programme in Feb 2020. VESPA currently distributes 54 data services which are searchable according to observing conditions and encompass a wide scope including surfaces, atmospheres, magnetospheres and planetary plasmas, small bodies, heliophysics, exoplanets, and lab spectroscopy. Versatile online visualization tools have been adapted for Planetary Science, and efforts were made to connect the Astronomy VO with related environments, e.g., GIS for planetary surfaces. The new programme will broaden and secure the former “data stewardship” concept, providing a handy solution to Open Science challenges in our community. It will also move towards a new concept of “enabling data analysis”: a run-on-demand platform will be adapted from another H2020 programme in Astronomy (ESCAPE); VESPA services will be made ready to use for Machine Learning and geological mapping activities, and will also host selected results from such analyses. More tutorials and practical use cases will be made available to facilitate access to the VESPA infrastructure.

VESPA portal: http://vespa.obspm.fr

The Europlanet 2020/2024 Research Infrastructure projects have received funding from the European Union's Horizon 2020 research and innovation programme under grant agreements No 654208 and No 871149
A geochemical approach to reconstructing sediment dynamic and thermohaline circulation in the western Mediterranean over the last deglaciation
Authors: Mesa-Fernández Jose Manuel , Martínez-Ruiz Francisca , Rodrigo-Gámiz Marta , Jiménez-Espejo Francisco J.
Published: March 2020

The westernmost Mediterranean basins is an exceptional and sensitive region for reconstructing past climate and oceanographic conditions. Geochemical signatures from diverse sediment records in the Alboran Sea and the Balearic basin, in particular, Ti/ca and Fe/Ca ratios, as proxies for the relative abundance of siliciclastic vs. carbonate fraction, have been investigated. These have also been compared with other previously studied records from the western Mediterranean and the Gulf of Cadiz to elucidate the mechanisms triggering the relative variations between the carbonate and siliciclastic fraction. The lithogenic fraction represents around 70% of the sediment in the Alboran basin, which mainly derived from riverine discharge and coastal erosion. Resuspension of fine sediment particles from the slope and the sea floor by bottom-water currents is a relevant process in these basin. The studied records are located between 850 m and 2400 m below the sea level, under the influence of the Western Mediterranean Deep Water (WMDW), which is restricted to a water depth below 500-600 m and to the Moroccan margin. This deep current is formed in the Gulf of Lion, when the superficial and intermediate waters sink by a density increase, and flow out the basin through the Gibraltar Strait, contributing to the Mediterranean Outflow Water (MOW) along with the Levantine Intermediate Water (LIW). The WMDW formation is enhanced during cold and arid periods. The comparison with other previously studied records, support important variations of the mechanisms triggering the relative contribution of carbonate and siliciclastic fractions during the last 20,000 yrs. The, Ti/Ca and Fe/Ca ratios increased during cold and arid periods, such as the Heinrich Event 1 (HE1) and the Younger Dryas (YD). These changes are more prominent in the Balearic basin and the eastern Alboran basin than in the western Alboran basin and the Gulf of Cadiz. Thus, we hypothesized that the increase in the Ti/Ca and Fe/Ca ratios is rather related to the enhanced WMDW production and more remobilization of fine siliciclastic sediments.
Abstract title; Geology and geochemical characteristics of coal-bearing source rocks in Nariin sukhait deposit, southern Mongolia
Authors: Baigalmaa Norov , Ogata Takeyuki , Jargal Luvsanchultem , Erdenetsogt Bat-Orshih , Erdenebayar Jamsran
Published: March 2020

The Nariin Sukhait mine is located in the southwest of Umnugobi province 50 kilometers from Mongolia's border with China at Shivee Khuren within the Nariin Sukhait deposit, which has relatively complex geological features. The most prominent feature relating to the Nariin Sukhait coal deposit is the arcuate, east-west trending Nariin Sukhait fault. The coal-bearing section, interpreted to be middle Jurassic in age, is exposed primarily in a window adjacent to this fault.

The chemical composition of whole indicates (variable composition, values of the ratio Th/U > 3.8-4.2, values Th/Sc 0.3-0.8, values LaN/YbN > 5 and values Eu/Eu* 0.6-0.9) indicates components derived from the active continental margin type. The low CIA values (50–60) indicate the absence or poor chemical weathering in the source area.

SEM-CL-imaging of sandstone quartz from Nariin sukhait show three types of quartz:  early Q1 cementation has gray to slightly grey luminescences, postdated compaction, and reduced intergranular porosity associated with illite formed during eogenesis. Q2 is characterized by dark luminescence overgrowths and is more voluminous in the thinly bedded sandstones than in the thickly bedded sandstones filling most of the remaining pore space during mesogenesis. Q3 was formed during the early telogenesis stage fully cementing the sandstones and the fractures were filled by hydrothermal chlorite and sulfides. Significant amounts of trace elements Al, Ti, Ca, K and Fe has been detected in quartz overgrowths. Al varies consistently between each cement with averages of 1324, 1523, and 1352 ppm for the Q1, Q2, and Q3 generations, respectively.

The geochemical, SEM-CL imaging and EPMA data results suggest a relatively igneous source, whit felsic composition. The sedimentary environment of the sandstone and argillite of these sedimentary rocks was the poor chemical weathering in the source area.
Quantifying the contribution of airborne gravity data for geoid modeling: two case studies
Authors: Jiang Tao , Dang Yamin , Zhang Chuanyin
Published: March 2020

Airborne gravimetry has become increasingly important for geoid modeling because of its capability of collecting large scale gravity data over difficult areas. In order to quantify the contribution of airborne gravity data for geoid determination, two regions with distinct topographical condition, a hilly desert area in Mu Us of China and a mountainous region in Colorado of the USA were selected for gravimetric geoid modeling experiment. The gravimetric geoid model computed by combining satellite gravity model, terrestrial and airborne gravity data fits with GPS leveling data to 0.8 cm for Mu Us case and 5.3 cm for Colorado case. The contribution of airborne gravity data to the signal and accuracy improvement of the geoid was quantitatively evaluated for different spatial distribution and density of terrestrial gravity data. The results demonstrate that in the cases of the spacing of terrestrial gravity points exceeds 15 km, the additions of airborne gravity data improve the accuracies of gravimetric geoid models by 11.1%~48.3% for Mu Us case and 13%~20% for Colorado case.
Environmental impact of crop diversification in steep vineyards
Authors: Iserloh Thomas , Dittrich Felix , Treseler Cord-Heinrich , Frey-Treseler Katharina , Hüppi Roman , Six Johann , Thiele-Bruhn Sören , Seeger Manuel
Published: March 2020

The intensification of European agriculture leads to soil degradation, reduction of biodiversity and an increased economic risk for the farmers. An approach towards solving this problem is crop diversification and the optimized use of resources. Increasing agricultural efficiency/resilience through diversification and the associated falling environmental costs could contribute to the growth of the European agricultural sector by adapting the entire value chain.

The EU-funded project DIVERFARMING (Horizon 2020 no 728003) aims to develop and deploy innovative farming and agribusiness models based on crop diversification. Germany is involved with a broad-based study in organic steep slope viticulture in Wawern (Saar Valley).

A fundamental issue of steep slope viticulture is related to vegetation management below the vines. In order to overcome problems of soil erosion and soil organic matter depletion, an increasing number of winemakers is establishing cover crops such as grasses and legumes in driving lanes. On the contrary, the area underneath the vines is typically kept free of vegetation to avoid fungal diseases and competition on water. As cover crops do not benefit to the value chain and may compete with vines on water or have other adverse effects on vine performance, an alternative strategy for vegetation management underneath vines in steep slope viticulture is required.

Therefore, intercropping vines with perennial herbs like Thyme and Oregano growing underneath is a promising cropping practice to address the abovementioned issues. Both herbs are economically valuable and originate from dry and warm environments, which are typical for most viticultural areas. Furthermore, their relatively low need for water and flat-growing habitus is assumed to be suitable to cover the soil underneath the vines in order to protect against erosion and suppress weeds without having adverse effects on vine growth and -health. They can be marketed directly or indirectly as a concentrate for cosmetics, perfumes, nutritional supplements and food.

During the 5-year project, we will investigate impacts on and interactions between crops, soil ecological and physicochemical properties as well as erosion and emission of greenhouse gases to evaluate ecological benefits of crop diversification. Selected results obtained within the first two years of investigation will be presented.
Assessing the interactions of atmosphere and land surface over South Africa with convective-permitting coupled atmospheric-hydrological modeling
Authors: Zhang Zhenyu , Arnault Joel , Laux Patrick , Baade Jussi , Kunstmann Harald
Published: March 2020

Land degradation, as a major issue in South Africa, undermines water resources and land potential productivity, and threatens the ecosystem biodiversity and human activities. In the scope of accurately assessing the land degradation processes in multi-use landscapes, the atmosphere-land surface relations and the dynamics of land surface state variabilities need to be addressed in a detail. This requires Earth System modeling approaches jointly considering high-resolution atmospheric modeling, land surface and hydrological modeling frameworks. This study investigates the atmosphere-land interactions and land surface water-energy budget for South Africa using the Earth System Model WRF-Hydro. WRF-Hydro is the fully coupled atmosphere-land surface-hydrology modeling system, which enhances the Weather Research and Forecasting model with the overland and subsurface water routing processes. In the WRF-Hydro modeling setup, the atmospheric part is configured in a convection-permitting spatial resolution at 4 km, with horizontal grids of 650 × 500 points, covering area of Southern Africa. In the land surface, the gridded hydrological processes are routed on a 400 m fine hydrological subgrid, within a soil depth of 2 m. In this study, we perform the coupled simulation for the year of 2010 and show the validation of modeling results with multiple reference datasets. The water-energy budget in the land surface from coupled WRF-Hydro simulation is assessed on 22 primary hydrological drainage regions. Model results show that coupled atmospheric-hydrological modeling is able to represent the regional water and energy budget, and to resolve atmosphere-land surface interactions. This allows the further usage of the coupled atmospheric-hydrological modeling in the context of land degradation studies, e.g. under different land-use scenarios.
EUROVOLC Virtual Access to computational tools at INGV Pisa
Authors: de’ Michieli Vitturi Mattia , Martinelli Francesco , Cerminara Matteo , Montagna Chiara Paola , Esposti Ongaro Tomaso , Papale Paolo
Published: March 2020

While computational capabilities in volcano science are developing to progressively higher sophistication levels involving HPC, parallel programming, and extensive use of super-computers, there is an increasing demand for accessibility to low to intermediate-level models and codes that can support multi-disciplinary research carried out by experts other than physical modelers and code developers. Responding to such a need by the international community is the justification and objective of Virtual Access (VA) activities developed under the EUROVOLC project. The Volcano Dynamics Computational Centre (VDCC) at INGV Pisa is renown as one international leader in physical-mathematical modelling and numerical simulation of volcanic thermo-fluid dynamics processes occurring from the deep regions of magma rise and accumulation within the crust, to within the atmosphere during volcanic eruptions. VDCC has been developing a large set of computational tools during last 30 years, that are offered under EUROVOLC for Transnational Access (for the most sophisticated, computational demanding models and codes) as well as for VA for low to intermediate-level models and codes. The latter include from non-ideal, compositional-dependent, multi-component volatile-melt thermodynamics to steady-state magma ascent to fast-performing kinematic modelling of pyroclastic density currents. Here we illustrate the model capabilities, the procedures to both download the codes and perform web-based computation, and a few relevant examples of calculations available through VA, and show relevant statistics of access and download by the volcano community to-date.
Process-based simulation of snow cover evolution in ski resorts using the AMUNDSEN model: results and validation
Authors: Hanzer Florian , Günther Daniel , Strasser Ulrich , Premier Valentina , Callegari Mattia , Marin Carlo , Notarnicola Claudia
Published: March 2020

Snow management, i.e., snowmaking and grooming, is an integral part of modern ski resort operation. While the current snow cover distribution on the slopes is often well known thanks to the usage of advanced monitoring techniques, estimates about its future evolution are usually lacking. Management-enabled numerical snowpack models driven by meteorological forecasts can help to fill this gap. In the frame of the H2020 project PROSNOW such software tools are developed to be run on an operational basis with the aim to optimize snow management as well as the use of water and energy resources. As part of PROSNOW, model simulations for the ski resorts Seefeld and Obergurgl (both Austria) as well as Colfosco and San Vigilio (both Italy) are performed with the physically based snow model AMUNDSEN. In its particular snow management module, both socioeconomic and physical factors are considered, the former concerning the decision when, where and how much snow should be produced, and the latter considering the snowmaking conditions, i.e., how much snow can be produced in the current ambient conditions (in terms of temperature and humidity) and the given ski resort infrastructure (number and efficiency of snow guns, water availability, etc.).

In our contribution we show the implementation of snowmaking and grooming practices in the AMUNDSEN model, its adaptation to individual ski resorts, and how different potential snow management strategies are accounted for. Model results obtained using historical meteorological observations and hindcast simulations are validated against observations from numerous data sources such as Sentinel-2 snow cover maps, distributed snow depth measurements from groomers, temperature and humidity measurements from snow guns as well as water consumption recordings.