bluuebunny/crossref_metadata_2025 huggingface dataset:
Metamorphic P-T-t paths of high-pressure felsic and pelitic from the Qianlishan Complex and tectonic implications for the Khondalite Belt in the North China Craton
Authors: Wu Shangjing , Yin Changqing , Davis Donald W. , Zhang Jian , Qian Jiahui , Qiao Hengzhong , Xia Yanfei , Liu Jingna
Published: March 2020

The Khondalite Belt is an east-west-trending Paleoproterozoic continental-continental collisional belt, separating the Western Block of the North China Craton into the Yinshan Block and the Ordos Block from north to south. In the past years, extensive metamorphic and geochronological investigations for pelitic granulites have been carried out in the Khondalite Belt. However, felsic granulites attract just a little attention although they are widely exposed in the field and potentially preserve key high-pressure information, thus hindering better understanding of the tectonic processes and settings of this critical area. In this study, a link between ‘inter-layered’ felsic and pelitic granulites from the Qianlishan Complex of the Khondalite Belt was established based on comprehensive metamorphic analysis. Three distinct metamorphic stages including peak pressure (M1), post-peak decompression (M2) and late retrograde cooling (M3) stages have been identified in the felsic and pelitic granulites. Felsic granulites experienced high-pressure metamorphism up to ~12 kbar, while estimated peak pressure for pelitic granulites is 11-15 kbar. The decompression stage (M2) is represented by cordierite + sillimanite symplectite and/or cordierite coronae with conditions of 5.7-6.5 kbar/800-835 °C in pelitic granulites, and by garnet-sillimanite assemblages formed at conditions of >6.5 kbar/810-865 °C in felsic granulites. The later cooling stage (M3) is indicated by sub-solidus biotite-quartz-plagioclase symplectite and later melt crystallization. Clockwise P-T paths involving near-isothermal decompression and near-isobaric cooling were defined by these mineral assemblages and approximate P-T conditions, which suggest a continent-continent collisional event. SIMS zircon U-Pb dating yields a consistent metamorphic age of ~1.95 Ga from felsic granulites, interpreted as the timing of peak metamorphism. The results, combined with previously reported data, suggest that the Khondalite Belt formed by collision between the Yinshan and Ordos blocks at ~1.95 Ga.
Rainfall partitioning in three major types of forests in the Mid-hills of Nepal
Authors: Badu Manoj , Ghimire Chandra Prasad , Nuberg Ian , Bruijnzeel L. Adrian , Meyer Wayne S.
Published: March 2020

Naturally regenerating or planted forests of broadleaf and pine species occupy ca. 2.3 million ha (>52% of the total area) of the Mid-hills of Nepal and provide a range of forest products and ecosystem services to local and downstream populations. These forested catchments give rise to numerous rain-fed springs and streams that undergo wide fluctuations in seasonal flows because of the concentrated monsoon rainfall (June to September), steep topography and rapidly draining soils. However, current understanding of the hydrological functioning of these forested landscapes is limited, particularly concerning the changes in forest structure and composition through natural succession and anthropogenic disturbances related to forest use (mostly collection of firewood, litter and fodder). We measured gross rainfall (P), throughfall, stemflow and overland flow in three major forest types in a Mid-hills catchment of Central Nepal, viz.: a predominantly planted pine forest (PF, ca. 35 years old), natural broadleaf forest (BF) and a mixed pine-broadleaf forest (MF). Because of differences in the dominant products provided by the three forest types they are subject to different levels of use by the local population. The PF is used only occasionally (litter harvesting and leisure) while the MF and BF are used throughout the year for nearly all three products. For the period of study (June 2015 – December 2016), measured throughfall values for the PF, MF and BF were 77.5%, 73.7% and 72.0% of incident P, respectively, with corresponding stemflow values of 0.6%, 1.3% and 1.6%, resulting in rainfall interception values of 21.9%, 25.1% and 26.4% for the PF, MF and BF, respectively. Corresponding amounts of overland flow for the PF, MF and BF were 4.7%, 9.8% and 11.4% of net precipitation (throughfall + stemflow), reflecting the relative intensity of forest-use related disturbances. Consistent removal of biomass and associated effects on the forest floor were found to negatively affect soil hydraulic properties. Our results highlight the need to take into account the effects of differences in forest use intensity when evaluating the forest-water relationships in Nepal’s Mid-hills as well as other locally used or managed forested landscapes in similar environments.
Monitoring and Mapping of Soil and Snow Water Across Scales with Cosmic-Ray Neutron Sensor Networks and Mobile Platforms
Authors: Schrön Martin , Oswald Sascha E , Zacharias Steffen , Dietrich Peter , Attinger Sabine
Published: March 2020

Cosmic-ray neutron albedo sensing (CRNS) is a modern technology that can be used to non-invasively measure the average water content in the environment (i.e., in soil, snow, or vegetation). The sensor footprint encompasses an area of 10-15 hectares and extends tens of decimeters deep into the soil. This method might have the potential to bridge the scale gap between conventional in-situ sensors and remote-sensing data in both, the horizontal and the vertical domain.

Currently, more than 200 sensors are operated in the growing networks of national and continental observatories. While single CRNS stations are continuously monitoring the local water dynamics at fixed field sites, mobile CRNS platforms are used for on-demand soil moisture mapping at the regional scale. The sensors are rapidly operational on any ground- or airborne vehicle. The data is particularly useful to study hydrological extreme events, heatwaves, and snow melt/accumulation, and it is being applied in hydrological models and agricultural irrigation management.

In the presentation we will explore the potential of the CRNS method to support and complement in-situ and remote-sensing data for hydrological event monitoring. We will discuss ongoing research activities that are aimed at improving the operationality, frequency, and spatial extend of CRNS measurements. New measurement strategies that are currently explored are, for example: dense clusters of 20 CRNS stations fully covering a 100 hectare catchment; heat wave monitoring with mobile car-based CRNS; regular soil/snow water mapping using mobile CRNS on cars and trains; and airborne surveys using CRNS on gyrocopters.

Future CRNS observations could provide a valuable contribution to the multi-sensor approach, e.g. to help tracking and characterizing surface water movement, to map regional-scale soil moisture patterns, or to calibrate and evaluate satellite data.
Evaluation of Sea fog Detection Accuracy Based on Geostationary Satellite Image Using Machine Learning
Authors: Kim NaKyeong , Bak Suho , Jeong Minji , Yoon Hongjoo
Published: March 2020

A sea fog is a fog caused by the cooling of the air near the ocean-atmosphere boundary layer when the warm sea surface air moves to a cold sea level. Sea fog affects a variety of aspects, including maritime and coastal transportation, military activities and fishing activities. In particular, it is important to detect sea fog as they can lead to ship accidents due to reduced visibility. Due to the wide range of sea fog events and the lack of constant occurrence, it is generally detected through satellite remote sensing. Because sea fog travels in a short period of time, it uses geostationary satellites with higher time resolution than polar satellites to detect fog. A method for detecting fog by using the difference between 11 μm channel and 3.7 μm channel was widely used when detecting fog by satellite remote sensing, but this is difficult to distinguish between lower clouds and fog. Traditional algorithms are difficult to find accurate thresholds for fog and cloud. However, machine learning algorithms can be used as a useful tool to determine this. In this study, based on geostationary satellite imaging data, a comparative analysis of sea fog detection accuracy was conducted through various methods of machine learning, such as Random Forest, Multi-Layer Perceptron, and Convolutional Neural Networks.
Avalanches of the martian north polar cap
Authors: Becerra Patricio , Conway Susan , Thomas Nicholas ,   The HiRISE team
Published: March 2020

In 2008, the High Resolution Imaging Science Experiment (HiRISE) on board NASA’s MRO fortuitously captured several discrete clouds of material in the process of cascading down a steep scarp of the water-ice-rich north polar layered deposits (NPLD). The events were only seen during a period of ~4 weeks, near the onset of martian northern spring in 2008, when the seasonal cover of CO2 is beginning to sublimate from the north polar regions. Russell et al. [1] analyzed the morphology of the clouds, inferring that the particles involved were mechanically analogous to terrestrial “dry, loose snow or dust”, so that the events were similar to terrestrial “powder avalanches” [2]. HiRISE confirmed the seasonality of avalanche occurrence the following spring, and continued to capture between 30 and 50 avalanches per season (fig. 1b,c) between 2008 and 2019, for a total of 7 Mars Years (MY29–MY35) of continuous scarp monitoring.

In this work we will present statistics on these events, in an attempt to quantify their effect on the mass balance of the NPLD, and with respect to competing processes such as viscous deformation and stress-induced block falls that do not trigger avalanches [3,4]. We also use a 1D thermal model [5] to investigate the sources and trigger mechanisms of these events. The model tracks the accumulation and ablation of seasonal CO2 frost on a martian surface. Russell et al. [1] support an initiation through gas-expansion related to the presence of CO2 frost on the scarp. Therefore the amount of frost that lingers on different sections of the model scarp at the observed time of the avalanches will provide evidence either for or against this particular mechanism. We will present preliminary results and discuss their implications.

References: [1] P. Russell et al. (2008) Geophys. Res. Lett. 35, L23204. [2] D. McClung, P.A. Schaerer (2006), Mountaineers, Seattle Wash. [3] Sori, M. M., et al., Geophys. Res. Lett., 43. [4] Byrne et al. (2016), 6th Int. Conf. Mars Polar Sci. Exploration [4] C. M. Dundas and S. Byrne (2010) Icarus 206, 716.
Weaker AMOC in coupled models inhibits north tropical Atlantic impact on ENSO
Authors: Rodriguez-Fonseca Belen , Polo Irene , Mohino Elsa , Losada Teresa , Martín-Rey Marta , Keenlyside Noel , Mechoso C. Roberto
Published: March 2020

Observational studies have reported that interannual variability of sea surface temperature in two tropical Atlantic regions can act as ENSO predictors in different seasons and periods: boreal summer Atlantic Nino (AN) in negative phases of the Atlantic Multidecadal Variabil- ˜ ity (AMV); and boreal spring tropical north Atlantic (TNA) in positive AMV. The robustness of the AMV role in the interbasin connection remains an open question due to the short observational record. Using observations and pre-industrial climate model simulations, we demonstrate for the first time that latitudinal displacements of the Atlantic ITCZ act as a switch for the type of inter-basin teleconnection. During periods in which the Atlantic ITCZ is further equatorward (northward) AN (TNA) impacts ENSO. This ITCZ location can be 1 affected by several factors, including the inter-hemispheric SST gradients associated with AMV.Coupled models success in capturing the AN-ENSO connection. Nevertheless, they have difficulties in reproducing the TNA-ENSO connection because they overestimate rainfall in the southern tropical Atlantic. The TNA-ENSO connection occurs sporadically during periods when the ITCZ is shifted further northward in association with strong heat transports by the AMOC. Weaker AMOC periods in coupled models don't present the TNA-ENSO connection. State-of-the-art models still need to improve for correctly representing tropical Atlantic impact on ENSO.
Near real time monitoring of snow cover using webcam imagery
Authors: Tanis Cemal Melih , Arslan Ali Nadir , Rautiainen Miina
Published: March 2020

Environmental camera networks are growing in usage in different parts of the globe. Time series of webcam imagery from the camera networks are used in estimating snow cover properties. Fractional snow cover (FSC) and snow depth (SD) are two important parameters which can be estimated from the webcam imagery using image processing algorithms. Monitoring of snow cover from webcam imagery has the potential to be used in gap filling and validation of satellite derived products. It can also be used as a data source for snow monitoring in remote areas where manual measurements and in-situ sensor installation and maintenance are costly, especially under forest canopy which retrieval of signal from ground by satellites is a challenge. In this paper, we have used multiple webcams from MONIMET Camera Network in Finland and Finnish Meteorological Institute Image Processing Toolbox (FMIPROT) on the cloud to establish an automated processing chain which reports FSC and SD estimations in near real time, available in FMIPROT website. Image processing algorithms are implemented in the toolbox, the images from last year are also processed and the results are compared with ultrasonic in-situ measurements and values generated by visual inspections on images. In the website, estimations from the day-time images of the latest one month are visualized on interactive plots, along with time-lapse animations of images, with a latency of 3 hours.
VOC analysis in soils – Extending SPME to SPME-trap and SPME-trap with enrichment.
Authors: Brown Robert , Mayser Jan Peter , Widdowson Caroline , Chadwick Dave , Jones Davey
Published: March 2020

The ability of an agricultural soil to function and sustainably provide an increasing food supply for a rapidly increasing global population has become of vital worldwide importance. Traditionally, soil health has been determined on a physico-chemical basis with biological characteristics often being ignored. Although several biological methods have been proposed, to date, none of these methods adequately indicate soil health. One method proposed to correct these circumstances is profiling or fingerprinting the volatile organic compounds (VOCs) from soil. VOCs in soils originate from a large variety of biological sources; microbial, fungal, animal- and plant-derived. These volatilomes are vital to plant/fungi-microbe and animal/human-microbe interactions and therefore offer a potential reactive, functional diagnostic tool to determine soil health by investigating the intra and interspecies interactions.

The standard methodology for VOC profiling has been solid phase microextraction (SPME). This automated VOC extraction method allows the monitoring of the community structure, physiological state, and activity of any microbial community in a soil without the need of manual extraction or cultivation procedures. Other common techniques that could be used to monitor the VOC fingerprints from soils include high capacity sorptive extraction (HCSE) or thermal desorption using sorbent-packed tubes for passive, in-situ sampling of soil gas.

Combining each of these techniques with an innovative cryogen-free focussing and pre-concentration trap has two main advantages:

All extraction techniques can run on a single platform without the need to change the hardware.

Single (SPME-trap) and multiple extractions (SPME-trap with enrichment) can be carried out automatically on a single sample to increase the analytical sensitivity, thus achieving a comprehensive VOC profile.

In this microcosm study, soils were treated in three different ways and their VOC profiles investigated. A ‘good’ soil comprised of brown earth and compost, a ‘medium’ soil of unaltered brown earth and a ‘bad’ soil of brown earth held under eutrophic anaerobic conditions. 2 g of each soil was analysed with SPME-trap, SPME-trap with enrichment, HCSE and sorbent tubes. Both a targeted (phenol, p-cresol, isophorone, indole and trans-β-ionone) and untargeted approach indicates that there are significant differences between the different soil types. By increasing the sensitivity of the untargeted approach with SPME-trap enrichment, this study was able to extend the number of VOCs identified, allowing a much more comprehensive VOC profile and possibility to determine the actual functions of specific VOC produced by the soil microbial community.
Addressing the effects of bottom trawling on benthic processes using experimental and field studies in the Baltic Sea
Authors: Morys Claudia , Jakobsson Martin , Sköld Mattias , Masqué Pere , Brüchert Volker , Bonaglia Stefano , Bradshaw Clare
Published: March 2020

Bottom trawling is one of the most important anthropogenic disturbances affecting marine ecosystems and there has been increased attention to its impacts on seabed habitats as well as the structure and functioning of benthic ecosystems. The impact of bottom trawling is well-known with regard to benthic organisms. However, we still have a poor understanding of its effects on bentho-pelagic coupling and biogeochemical cycling in the sediment. In the Baltic Sea, the study area of the present investigation, there is a particular lack of data.
Here, we present new results from field experiments to quantify changes in sediment properties, macrofauna and biogeochemical cycling after the passage of a benthic dredge. To put the results in a broader context, a field survey was conducted in six areas of different commercial trawling intensities in the Bornholm Basin. Acoustic geophysical mapping, isotope profiling, functional categorization of macrofauna and sediment-water nutrient and oxygen flux measurements were used to evaluate the physical disturbance of the seabed. Preliminary results suggest a range of ecological, biogeochemical and physical impacts of trawling in the Baltic Sea, with implications for benthic ecosystem functioning.
Multi-Hazard Risk Governance framework and implementation challenges in Ganges-Brahmaputra-Meghna (GBM) Delta communities – linking science, policy and decision makers
Authors: Pal Indrajit , Szabo Sylvia
Published: March 2020

The Ganges and Brahmaputra rivers form in the Himalaya and its catchment is shared among five countries and ultimately deposits the freshwater and sediments in the Ganges-Brahmaputra-Meghna (GBM) delta shared between Bangladesh and India. The delta is strongly influenced by neighbouring countries’ water and sediment management decisions in addition to environmental, climatic and internal management. The coastal population is exposed to climate hazards, including fluvio-tidal floods, tropical cyclones accompanied by storm surges, river-bank erosion, saline water intrusion and arsenic contamination of shallow aquifers. It is also evident that, low income countries prioritize developmental activities for economic development. Hence, disaster prevention and control are not well integrated into socioeconomic activities, which increases exposures and even new disaster risks.

The concept of risk governance includes institutional and policy process to guide/monitor collective activities of a group or community to regulate, reduce or control risk problems. The multi-hazard risk assessment of Ganges Brahmaputra Meghna delta communities depicts the complexities in implementation of risk governance in developing country context. Risk governance has  also been emphasized in the global agreements like Sustainable Development Goals and Sendai Framework of Disaster Risk Reduction. SFDRR priority 2, states the strengthening of disaster risk governance to manage disaster risks with global targets of reducing economic loss, enhancing international cooperation and substantial increase in availability and access to disaster risk information fostering partnerships and collaboration.

Present study analyses the risk governance frameworks in the multi-hazard parlance to understand the effectiveness of policies and plan for the Ganges-Brahmaputra-Meghna (GBM) river delta communities. The qualitative research also reflects that experiences of developing countries on institutional parallelism and implementation challenges. The relationship between state and sub‑national governments has also been examined in the context of local governance systems (both formal and informal).
Talking WITH not talking AT
Authors: Thielen-del Pozo Jutta , Eeckels Adriaan , Hearn Paul , Jensen-Foreman Anne-Mette , Glovicko Jan
Published: March 2020

(Research and innovation are essential for a resilient society). Today, scientists have started to understand the complexities of global systems, know how to deal with uncertainties and have computing power for making predictions that did not exist before. As a result, the overall knowledge within the scientific community is increasing rapidly with unprecedented speed, while at the same time there is a tendency that the research fields narrow down and deepen and individual scientists are often so specialised that speaking about their work outside their specific research community becomes a challenge.
The Joint Research Centre of the European Commission operates at the interface between science and policy, and is taking a number of initiatives to address the challenge of how to effectively communicate scientific results to policymakers, citizens and stakeholders.  For policymakers robust data, facts and evidences are important and highly appreciated inputs, but not the only ones. Indeed, policymaking is a long process that requires continuous dialogue and exchange of information with all affected parties throughout the initiation, development and finalisation process. A final report of 500 pages summarising the outcome of a research project delivered towards the end of the drafting for a new regulation may not be taken into account, even if the results are highly relevant. 
Several JRC programmes have been piloted to improve communication with EU policy makers and to engage with citizens. The programmes are diverse and include the building of a network on clear writing, training through eLearning, thematic science-policy workshops, citizen engagement projects and events, exhibiting science at museums and a dedicated art and science programme complete with artistic residences and exhibitions. This presentation will illustrate a few examples of alternative ways for communicating science that provides societal context in an inclusive manner to address societal challenges.
Drought risk reduction for achieving Sustainable Development Goals
Authors: Van Loon Anne ,   Panta Rhei Drought in the Anthropocene group
Published: March 2020

Water is crucially important to most of the Sustainable Development Goals (SDGs). Not having enough water due to drought or water scarcity can result in food shortage, environmental degradation, reduced energy availability, poverty, illness and loss of life, migration and conflict. Lack of water also has intangible consequences related to equality, gender, and education that are often overlooked. These cascading socio-ecological impacts are most acute in the Global South where exposure and vulnerability to drought are high. African nations have therefore urged the international scientific community to support them by developing tools and data covering all aspects of drought risk (Padma, 2019). Our challenge is to increase our understanding of the relationship between water and society and how to use this understanding to improve water management and reduce drought risk. Real progress towards achieving the SDGs can only be made when our science is instrumental towards solving real-world problems. With the “Drought in the Anthropocene” group (90+ scientists working on the feedbacks between drought and society as part of the International Association of Hydrological Sciences’ Panta Rhei decade, https://iahs.info/Commissions--W-Groups/Working-Groups/Panta-Rhei/Working-Groups/Drought-in-the-Anthropocene.do) we are doing interdisciplinary research on which data and tools we can utilise to reduce drought risk around the world. Here, we will share many recent examples of our research on the links between drought and SDGs and discuss ways forward to use our increased scientific understanding to make actual impact towards achieving the SDGs.

 

Padma, T. V. (2019). African nations push UN to improve drought research. Nature, 573, 319-319.
Speleothem record of enhanced hydroclimate during MIS15a in Northeast Greenland
Authors: Moseley Gina , Edwards R. Lawrence , Spötl Christoph , Cheng Hai
Published: March 2020

The Arctic region is predicted to be one of the most sensitive areas of the world to future anthropogenically-forced climate change, the consequences of which will affect vast numbers of people worldwide, for instance through changes to mid-latitude weather systems and rising eustatic sea levels. Recent changes in temperature and precipitation, and those projected for the future, indicate that some of the greatest changes will occur in Northeast Greenland. Essential knowledge on the climate history of this region, which can be used to validate models and understand forcing mechanisms and teleconnections, is however absent. Here, we present a speleothem palaeoclimate record for Northeast Greenland (80 °N) that formed during Marine Isotopes Stage 15a  between 588 ka to 537 ka. The record indicates that at that time, Northeast Greenland was warmer and wetter than at present associated with a reduction in Arctic sea ice, thawing of permafrost in eastern Siberia (55 °N and 60 °N), and elevated warm conditions at Lake El’gygytgyn (67.5 °N), Russia.
Developing reservoir sediment ceramsite as a novel growing medium: I low temperature and anaerobic production
Authors: Liu Yu-Hsiang , Chu Yi-Hao , Cheng Chih-Hsin
Published: March 2020

Ceramsite is a typical substrate used in soilless culture systems. It is clean and durable but usually shows poor performance in water and nutrient retention capacity. In this study, we used reservoir sediment as the material to produce ceramsite to use as a growing medium. We sintered it under relatively low temperature (600°C, 800°C, and 1000°C) and anaerobic conditions with and without organic matter addition (5%, 10%, and 15%). We examined their water holding capacity, bulk density, mechanic strength, and pH, which were related to the essential characteristics using the growing media. The results showed that organic matter addition decreased bulk density and mechanic strength but increased water holding capacity and pH. The sintering temperature has less influence on bulk density and water holding capacity but increased mechanic strength and pH with the increasing sintering temperature. Compared with the commercial high-temperature ceramsite and lava rock, the water holding capacity in our ceramsite can be three times higher than those. The microstructure from scanning electronic microscopy indicated the rough surface in ceramsite at 600°C and 800°C but became glassy surface at 1000°C which was similar to the commercial ceramsite and lava rock that showed more glassy and non-porous surface. The addition of organic matter maintained rough surfaces at 1000°C, which can be the mechanism to have higher water and nutrient retention. Our results suggest that the ceramsite produced from reservoir sediment under lower temperature and anaerobic conditions with organic matter addition can be used as a growing medium to replace commercial ceramsite with its better water retention capability.

 
Examining the links between multi-frequency backscatter, geomorphology and benthic habitat associations in Marine Protected Areas
Authors: Runya Robert Mzungu , McGonigle Chris , Quinn Rory
Published: March 2020

Acoustic methods are frequently used to provide broad-scale information on the spatial extent, range and distribution of marine habitats and sedimentary environments. Although single frequency multibeam echosounders have dominated seabed mapping for decades, multi-frequency approaches are starting to present in the scientific literature. Multibeam survey strategies are generally optimized for the acquisition of bathymetry data, often overlooking the ecological and geological value of backscatter data. This study examines the benefits of combining multi-frequency backscatter responses to discriminate seabed properties in areas with strong geomorphological gradients and associated ecological variability. The frequency-dependence element of backscatter strength is linked to: (i) the dominant scattering regime, (ii) seabed roughness, and (iii) the input of volume scattering related to signal penetration. In 2019, we collected and analyzed multifrequency (200, 95 and 30-kHz) backscatter data from Hempton’s Turbot Bank, a marine protected area off the north coast of Ireland. We compare these data with legacy 300 kHz backscatter data from 2013 to explore the backscatter variability in the context of geomorphological change. We assess the explanatory power of multi-frequency vis-à-vis single-frequency backscatter data in terms of bathymetry, sediment granulometry and infaunal community structure. Results improve our understanding of the link between backscatter properties and geomorphology, with specific recommendations towards minimizing information loss and establishing minimum data requirements for frequency-based benthic habitat discrimination. Improved discrimination of geomorphology and benthic habitat characteristics enhances the reliability of backscatter data as a monitoring technique for area-based protection of marine resources.
Observations and simulations of electron flux oscillations in response to broadband ULF waves
Authors: Li Xinlin , Sarris Theodoros , Temerin Michael , Zhao Hong , Khoo Leng Ying , Turner Drew , Liu Wenlong , Claudepierre Seth
Published: March 2020

It has recently been demonstrated through simulations and observations that flux oscillations of hundreds-keV electrons are produced in the magnetosphere in association with broadband Ultra Low Frequency (ULF) waves (Sarris et al., JGR, 2017). These oscillations are observed in the form of drift-periodic flux fluctuations, but are not associated with drift echoes following storm- or substorm-related energetic particle injections. They are observed in particular during quiet times, and it has been shown that they could indicate ongoing radial transport processes caused by ULF waves. It has also been shown that the width of electron energy channels is a critical parameter affecting the observed amplitude of flux oscillations, with narrower energy channel widths enabling the observation of higher-amplitude flux oscillations; this potentially explains why such features were not observed regularly before the Van Allen Probes era, as previous spacecraft generally had lower energy resolution. We extend these initial results by investigating the association between the observed flux oscillations with the amplitude of electric and magnetic fluctuations in the ULF range and with Phase Space Density gradients, both of which are expected to also affect radial transport rates.
Crowd-based observations of riverine macroplastic pollution
Authors: Strobl Barbara , van Emmerik Tim , Seibert Jan , Etter Simon , den Oudendammer Tijmen , Rutten Martine , van Meerveld Ilja
Published: March 2020

Plastic debris in aquatic environments is an emerging environmental hazard. Macroplastic pollution (>5 cm) negatively impacts aquatic life and threatens human livelihood, on land, in oceans and within river systems. Reliable information of the origin, fate and pathways of plastic through river systems are required to optimize prevention, mitigation and reduction strategies. Yet, accurate and long-term data on plastic transport are still lacking. Current macroplastic monitoring strategies involve labor intensive sampling methods, require investment in infrastructure. As a result, these measurements have a low temporal resolution and are available for only a few locations. Crowd-based observations of riverine macroplastic pollution may offer a way for more frequent cost-effective data collection over an extensive geographical range. In this presentation we demonstrate the potential of crowd-based observations of  floating plastic and plastic on riverbanks. We extended the existing CrowdWater smartphone app for hydrological observations with a module for plastic observations in rivers. We analyzed data from two cases: (1) floating plastic in the River Klang, Malaysia, and (2) plastic the banks of the River Rhine in The Netherlands. Crowd-based observations of floating plastic yield similar estimates of plastic transport, distribution of plastic across the river width, and polymer composition as reference observations. The riverbank observations provided the first data of plastic pollution on the most downstream stretches of the Rhine, revealing peaks close to urban areas and an increasing plastic density towards the river mouth. With this presentation we aim to highlight the important role that crowd-based observations of macroplastic pollution in river systems can play in future monitoring strategies to provide complementing data of plastic transport composition at a higher spatial and temporal resolution than is possible with standard methods.
Leveraging crystal-scale data to constrain the conduit flow regime in persistently active volcanoes
Authors: Suckale Jenny , diBenedetto Michelle , Qin Zhipeng
Published: March 2020

Persistently active volcanoes are often closely monitored, yielding a rich archive of observational data. The availability of varied observations provides a unique opportunity for improving theoretical models of magma dynamics, but data and model can be difficult to compare directly. Geophysical observations like seismicity or geodetic measurements often operate at similarly large scales as many models, but they only provide indirect and non-unique testimony of the processes occurring at depth. In contrast, crystals in erupted tephra or scoria samples record at least some aspects of the pre-eruptive condition in the volcanic conduit directly, but refer to spatial scales that are much smaller than most models resolve.

The goal of this paper is to demonstrate the potential of crystalline-scale data for distinguishing directly between different conduit-flow models. As a proof of concept, we focus on the preferential alignment of olivines crystals from tephra erupted at Kilauea Iki in 1959. Prior petrographic analysis suggests that these olivine glomerocrysts formed through synneusis of individual crystals. To evaluate the fluid-dynamical conditions under which both crystal synneusis and preferential crystal alignment would occur, we compare two broad classes of conduit flow models, unidirectional and bidirectional models.

We hypothesize that the observed preferential alignment of olivine crystals is created by a pronounced, nearly stationary wave at the interface that separates the ascending and descending magmas in bidirectional flow models. Crystals in bidirectional flow are hence exposed to a superposition of wave and shear, while crystals in a unidirectional, laminar flow experience approximately constant shear strain during ascent. To test our hypothesis, we quantify the crystal alignment resulting from a pure shear flow and from the superposition of a stationary wave on shear flow through two complementary model approaches. We first derive an analytical model for when crystals align under the joint influence of a wave and shear flow. We then use direct numerical simulations to quantify how crystal-crystal interactions modulate the analytically predicted preferential alignment of crystals.

We find that the formation of glomerocrysts with preferential aligned olivine crystals is consistent with bidirectional flow models, but unlikely to form in a unidirectional model. We emphasize that the imprint of the conduit flow on the crystals is subtle, suggesting that both clustering or alignment in isolation would be compatible with a much wider range of flow conditions than the observed conjunction of both attributes in the Kilauea Iki olivines. To our knowledge, these observations provide the first direct evidence of bidirectional flow in volcanic conduits.
European Lunar Cargo Lander: Performance figures and community opportunities
Authors: Buchwald Robert , Sandrone Silvio , Schrage Thomas , Mirra Carlo
Published: March 2020

The European Large Logistic Lander (EL3) is an ESA proposed contribution to the international human Moon exploration efforts. EL3 would be capable of flying a variety of missions. In the frame of the American Artemis program, EL3 would provide increased capabilities for science and technology payloads as well as supporting lunar surface asset deployment for longer surface expeditions. Besides this, also self-standing European science and exploration missions as well as a sample return scenario using gateway and Orion infrastructure for returning surface samples from the lunar far side back to Earth are part of the lander's portfolio.

Being envisaged as a modular and versatile system, payloads could be delivered to any longitude or latitude on the Moon. Hazard avoidance capabilities would enable accessing clustered and rocky areas on the surface, which were out of reach for missions of the past. Lunar night survival technologies could allow long term science observations and repeated operations of ISRU plants.

ESA is in exchange with the international community on the definition of common user requirements which address NASA's needs whilst also expressing the European vision. First industrial studies have been awarded for paving the way towards a sustained exploration of the Moon. A regular exchange between the EL3 user community and the industrial teams is planned to be organized soon to allow capturing all relevant stakeholder needs right from the beginning.
Regime-dependent statistical post-processing of ensemble forecasts
Authors: Allen Sam , Ferro Christopher , Kwasniok Frank
Published: March 2020

A number of realizations of one or more numerical weather prediction (NWP) models, initialised at a variety of initial conditions, compose an ensemble forecast. These forecasts exhibit systematic errors and biases that can be corrected by statistical post-processing. Post-processing yields calibrated forecasts by analysing the statistical relationship between historical forecasts and their corresponding observations. This article aims to extend post processing methodology to incorporate atmospheric circulation. The circulation, or flow, is largely responsible for the weather that we experience and it is hypothesized here that relationships between the NWP model and the atmosphere depend upon the prevailing flow. Numerous studies have focussed on the tendency of this flow to reduce to a set of recognisable arrangements, known as regimes, which recur and persist at fixed geographical locations. This dynamical phenomenon allows the circulation to be categorized into a small number of regime states. In a highly idealized model of the atmosphere, the Lorenz ‘96 system, ensemble forecasts are subjected to well-known post-processing techniques conditional on the system's underlying regime. Two different variables, one of the state variables and one related to the energy of the system, are forecasted and considerable improvements in forecast skill upon standard post-processing are seen when the distribution of the predictand varies depending on the regime. Advantages of this approach and its inherent challenges are discussed, along with potential extensions for operational forecasters.
The INGV Arctic Ionospheric data management system and its synergy with the Italian NADC
Authors: Pica Emanuele , Romano Vincenzo , Marcocci Carlo , Cesaroni Claudio , Hunstad Ingrid
Published: March 2020

The Space Weather effects on the ionosphere considerably affect several modern technology infrastructures, such as telecommunication systems, power networks and in general systems relying on satellite navigation. The polar regions have always been a natural laboratory for the analysis of these phenomena and regular observations are required to gain better knowledge about the relationships between the ionized atmosphere and the others atmospheric layers as well as to provide support to civil aviation and maritime for the safety of the polar routes.

The Istituto Nazionale di Geofisica e Vulcanologia (INGV) has a long history in acquiring ionospheric data in the polar regions and currently operates in the Arctic two permanent observatories in Svalbard (Ny-Ålesund and Longyearbyen), Norway, equipped with three GNSS receivers for scintillation and TEC measurement. An additional receiver will be installed soon at the Thule Air Base (Greenland).

The uninterrupted data production from these instruments and the necessity to provide near real-time access to this information makes it necessary to develop suited procedures and ad-hoc IT infrastructures. To address these needs the INGV designed the SWIT system (Space Weather Information Technology) for data management and the web-platform eSWua (electronic Space Weather upper atmosphere) for data dissemination. With regard to the Arctic region, the information-flow from Svalbard stations is provided by optical fibre connections and the SWIT-DBMS operates the ingestion of this data at the INGV central repository within 15 minutes or less. The eSWua website offers a GUI for near real-time and historical data visualization, while web-based tools and a RESTful web-service will provide free access to the data at different processing levels. The planning and design of this infrastructure takes advantage of the experience gained from ongoing projects like the NADC (the Italian National Antarctic Data Center).

In this paper the state of the art of the INGV Arctic and Antarctic data management system for the Ionospheric and space weather data and the efforts undertaken to improve the access and availability of these information are presented and discussed.
Microstructural insights into the compressive failure of snow based on a peridynamic framework
Authors: Ritter Jonas , Löwe Henning , Zaiser Michael
Published: March 2020

Highly-porous cohesive granular materials such as snow possess complex modes of failure. Apart from classical failure modes, they show microstructural failure and fragmentation associated with densification within a local, narrow zone. Therefore cracks may form and propagate even under compressive load (‘anticracks’,’compaction bands’). Such failure modes are of importance in a range of geophysical contexts. For instance, they may control the release of snow slab avalanches and influence fracturing of porous rock formations. In the snow context, specific failure mechanisms of the ice matrix and their interplay with the microstructure geometry of snow are still poorly understood. Recently, X-ray computed tomography images have provided insights into snow microstructure and capability of directly simulating its elastic response by the finite element method (FEM). However, apart from thermodynamically driven healing processes the inelastic post-peak behaviour of the microstructure is controlled by localized damage, large deformations and internal contacts. As a result of the well-known limitations of FEM to capture these processes we use Peridynamics (PD) as a non-local continuum method to approach the problem. Due to its formulation, (micro)cracks and damage are emergent features of the problem solution that do not need to be known or located in advance. Furthermore, the Lagrangian character of the governing equations makes the method suitable for simulating large deformations. In this contribution we perform confined uniaxial compression simulations of snow microstructures within a peridynamic framework. Computed tomography images of snow specimen serve as a simulation data base. The obtained results show a novel insight into local failure of snow and allow a better comprehension of the underlying failure mechanisms. This study contributes to improve non-local macroscopic constitutive models for snow for future applications.
Rapid Detection of Earthquake Rupture Directivity Using Strong Ground Motion Data in Taiwan
Authors: Wu Cheng-Feng , Lin Ting-Li , Chen Ying-Chi
Published: March 2020

In the past decade, there have been several disaster earthquakes occurred in Taiwan.
From the observed data of the disaster earthquakes, the stations located in the source
rupture direction have obvious directivity pulses, and the distribution of the earthquake
disaster is related to the peak ground velocity. Therefore, how to use a large and high-
dense seismic database to develop a near-real-time detection system on the earthquake
rupture directivity, which is a very important task in Taiwan. In this study, we determine
the earthquake rupture directivity using near-field velocity data from 1991 to 2018, which
were collected under the Taiwan Strong Motion Instrument Program (TSMIP). The used
method is mainly constructed in the interpolation of the peak-ground-velocity map and
the directional attenuation regression analysis. Through the analysis of moderate-to-large
magnitude (M L > 5.5) seismic events, the source rupture directivity can be detected
effectively and quickly by the applied method. The detection results are also comparable
with those from the previous source studies. We also find out a linear relationship between
the directivity effect and earthquake magnitude. Since the TSMIP station may provide
real-time services in the future, the detection system proposed by this research can quickly
provide disaster prediction information, which is of great importance for earthquake
emergency response and hazard mitigation.
An affordable, fully-automated minirhizotron system for observing fine-root dynamics
Authors: Thomsen Simon , Jensen Kai
Published: March 2020

For the understanding of the carbon cycle in terrestrial ecosystems as well as of plant stress responses to drought and hypoxia, the study of fine root dynamics plays an important role. However, the number of relevant studies is still limited, which may be due, among other things, to the high costs of commercial minirhizotron systems. Here, we present an affordable (<500 €) and fully automated minirhizotron system, utilizing new developments in low-cost electronics and 3D-printing. The camera system is based on a Raspberry Pi and can be controlled by the user via a Python-based GUI. The open source character of the program also allows it to be adapted to the needs of the user or other requirements. The camera is controlled automatically by a stepper motor, which allows the precise recording of images at defined depths. The highest possible resolution is 3280 x 2464 pixels (8 MP) for an image area of about 2.5 cm x 2.5 cm, thus allowing the imaging of even root hairs and fungal hyphae. The structural components were manufactured using 3D printing. To protect against moisture, the camera and drive system are installed in a waterproof acrylic tube (60 mm diameter), which in turn is inserted into the rhizotron tubes (70 mm diameter) used in the field, making it possible to use the system in humid ecosystems.