bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of drying and rewetting cycles on denitrification and greenhouse gas emissions in normally saturated organic substrate
Authors: Birgand François , Maxwell Bryan , Thomas Augustin , Schipper Louis , Williams David , Christianson Laura , Tian Shying , Helmers Matthew , Chescheir Chip , Youssef Mohamed
Published: March 2020

The effects of intermittent drying of normally saturated organic systems such as peatlands, swamps, or wetlands has not been reported quite as often as those of wetting and drying cycles of normally dry soils. We report here the effects of weekly drying and rewetting events on saturated woodchips used as denitrification bed. We used denitrification rates and gas effluxes as indicators of the response of normally saturated organic substrate to intermittent aerobic conditions. We used replicated eight upflow columns in the lab fed with nitrated water, and undergoing variable duration of intermittent aerobic conditions (none, 2, 8, and 24 hours) over a 400d experiment.  We used high-frequency sensors to measure in- and outflow nitrate and DOC concentrations on a 2-hour basis, from which we calculated denitrification rates. We also measured the CO2 and N2O effluxes in the headspace on an hourly basis. The results show a burst of respiration activity during drying events and for several days after rewetting. Isotopic data suggest that respiration was bacterial denitrification. Intermittent aerobic conditions seem to provide the conditions conducive to the generation of more and better quality DOC, which microbes use during subsequent saturated conditions. Our results suggest that intermittent aerobic conditions may have lasting impacts on microbial respiration in wetlands.
INTAROS joint assessment of scientific and community-based observation programs
Authors: Danielsen Finn , Pirazzini Roberta , Eicken Hajo , Fidel Maryann , Iversen Lisbeth , Johnson Noor , Lee Olivia , Poulsen Michael K. , Pulsifer Peter L. , Sagen Hanne , Sandven Stein
Published: March 2020

The dramatic changes occurring in the Arctic due to the global warming generate feedbacks on global circulation and midlatitude climate and, at the local scale, pose challenges to Arctic populations and infrastructures and threaten the Arctic fauna and flora. Observations in the Arctic are needed to understand the ongoing geophysical and socio-ecological processes and changes, to plan adaptation strategies, and to sustainably manage the environment. A joint effort from the scientific and societal communities is necessary to monitor relevant phenomena in such a vast and poorly accessible area of the globe.

The integration of citizen and science observations is envisioned by the Sustaining Arctic Observing Networks (SAON) as a key element of the Roadmap for a comprehensive long-term pan-Arctic Observing and Data System (ROADS) that serves societal needs. Often, however, the different language and methodology adopted by scientific and non-scientific communities hamper the exchange and usability of the available observations. In the EU INTAROS project, metadata on community-based and scientific observing programs were collected using a common questionnaire in order to assess gaps and strengths in the observing systems.

The assessment revealed that the community-based observations rarely belong to long-term sustained programs, and suffer from lack of long-term preservation strategies more severely than science-based observing systems. On the other hand, many science-based marine observations are collected only during the summer season, while community-based observations are less prone to temporal gaps. Community-based monitoring efforts can help increase observational coverage in space and time with often low-cost approaches, while also adding value through the introduction of holistic perspectives – such as Indigenous knowledge-based – into the observing process.

Our analysis demonstrated that, despite the differences in method and language between community- and science-based programs, the adopted assessment methodology enables the comparison and, thus, the integration of the metadata (that e.g. describe frequency of observations, locations, types of variables observed etc.) pertaining to community and science-based observing systems.
The NEMO (Nucleus for European Modelling of the Ocean) numerical ocean platform
Authors: Samson Guillaume , Levy Claire , System Team Nemo
Published: March 2020

The Nucleus for European Modelling of the Ocean (NEMO) is a state-of-the art modelling platform for oceanographic research, operational oceanography, sesonnal forecasts and climate studies. NEMO includes three major components; the blue ocean (dynamics), the white ocean (sea-ice), the green ocean (ocean biogeochemistry). It also allows coupling through interfaces with atmosphere (through OASIS software), waves, ice-shelves, so as nesting through the adaptive mesh refinement software AGRIF. Some reference configurations and test cases allowing to explore, to set-up and to validate the applications, and a set of tools to use the platform are also available to the community. The whole platform and its documentation are available under free licence.

The evolution and reliability of NEMO are organised and controlled by a European Consortium between CMCC (Italy), CNRS (France), MOI France), NOC (UK), UKMO (UK).

Consortium members agree on long term strategy and yearly plans, sharing expertise and efforts within the NEMO System Team: the core team of NEMO developers in order to ensure the successful and sustainable development of the NEMO System as a well-organised, state-of-the-art ocean model code system suitable for both research and operational work
Unforced oscillations of climate and AMOC under Glacial climate in MIROC 4m AOGCM
Authors: Abe-Ouchi Ayako , Chan Wing-Le , Sherriff-Tadano Sam , Obase Takashi , Mitsui Takahito , Kawamura Kenji , Oka Akira , Yoshimori Masakazu , Ohgaito Rumi
Published: March 2020

The glacial period was punctuated by abrupt millennial scale climate changes, such as Dansgaard Oeschger events, Boeling-Allerod and Younger Dryas. Although abrupt climate changes were shown to have a strong link to the shift between the (quasi) multiple equilibria of Atlantic Meridional Overturning Circulation (AMOC), modeling both together the stability of AMOC under different climate condition and observed glacial-deglacial climate change with fully coupled ocean-atmosphere GCM have been challenging. Here we present a series of long transient experiments (> 10, 000 years) with steadyforcing under different glacial condition summarized as a phase diagram and compared them with simulation under transient forcing experiments following PMIP4 using a coupled ocean-atmosphere model, MIROC4m AOGCM. The simulated LGM AMOC is weaker and shallower than the modern AMOC under Pre-Industrial condition. Conventional stability diagram for varied freshwater flux as well as phase diagram showing the response of the AMOC and climate to steady forcing is first obtained. It is shown that (quasi-) multiple equilibria exist indeed under a certain range of climate condition. When a steady forcing under glacial condition is applied even without freshwater perturbation, however, the whole climate-ocean system shows self-sustained oscillation with bipolar seesaw pattern and changes between interstadials and stadials, whose periodicity or the return time ranges from 1000 years to nearly 10000 years depending on the background forcing, e.g. Greenhouse Gas levels. We show that the Southern Ocean plays important role in determining the condition of oscillations. It implies that the abrupt climate change during the glacial climate and deglaciation can be induced much more frequently when the coupled climate system enters the region of the AMOC oscillatory mode than outside of the region. Implication on the mechanism and the conditions of the millennial scale climate changes for the past time period is discussed.

 
The ExoMars Trace Gas Orbiter – First Martian Year in Orbit
Authors: Svedhem Håkan , Korablev Oleg , Mitrofanov Igor , Rodionov Daniel , Thomas Nicholas , Vandaele AnnCarine , Vago Jorge L. , Forget Francois , Wilson Colin
Published: March 2020

The Trace Gas Orbiter, TGO, has in March 2020 concluded its first Martian year in its 400km, 74 degrees inclination, science orbit. It has been a highly successful year, starting with the rise, plateau and decay of the major Global Dust Storm in the summer of 2018. This has enabled interesting results to be derived on the water vapour distribution, dynamic behaviour and upward transport as a consequence of the dust storm. The characterisation of the minor species and trace gasses is continuing and a large number of profiles is produced every day. A dedicated search of methane has shown that there is no methane above an altitude of a few km, with an upper limit established at about 20 ppt (2∙10-11). The solar occultation technique used by the spectrometers has definitely proven its strength, both for its high sensitivity and for its capability of making high resolution altitude profiles of the atmosphere. Climatological studies have been initiated and will become more important now that a full year has passed, even if the full potential will be visible only after a few Martian years of operation. The FREND instrument has characterised the hydrogen in the shallow sub-surface on a global scale at a spatial resolution much better than previous missions have been able. It has found areas at surprisingly low latitudes with significant amounts of sub-surface hydrogen, most likely in the form of water ice. The CaSSIS camera has made a high number of images over a large variety of targets, including the landing sites of the 2020 ESA and NASA rovers, Oxia Planum and the Jezero Crater. Stereo imaging has enabled topographic information and precise 3-D landscape synthesis.

This presentation will summarise the highlights of the first Martian year and discuss planned activities for the near and medium term future.

The ExoMars programme is a joint activity by the European Space Agency (ESA) and ROSCOSMOS, Russia. It consists of the ExoMars 2016 mission, launched 14 March 2016, with the Trace Gas Orbiter, TGO, and the Entry Descent and Landing Demonstrator, EDM, named Schiaparelli, and the ExoMars 2020 mission, to be launched in July/August 2020, carrying a Rover and a surface science platform to the surface of Mars.
Water Saving in the Semi-Arid Doukkala Irrigation Scheme (Western Morocco)
Authors: El Ghandour Fatima Ezzahra , Habib Adnane , Houali Youssef , Labbassi Yassine , Iannini Lorenzo , Alfieri Silvia Maria , Labbassi Kamal , Menenti Massimo
Published: March 2020

Investigations carried out under the MOSESH2020 project in the Doukkala irrigation scheme (western Morocco) allowed the generation of several data products during the agricultural seasons 2016-2017 and 2017-2018: Seasonal probabilistic weather forecast, Early-season and In-season crop mapping, Monitoring of crop water demand and Short-term forecasts of irrigation water requirements.

This study was focused on the assessment of the adequacy of the water applied to meet the crop water demand in the two irrigation seasons 2016-2017 and 2017-2018.

Monitoring of Crop Water Demand (CWD) was based on the estimation of the maximum crop evapotranspiration, obtained from remote sensing data of the monitored area. Such output is updated frequently (e.g. every week) during the irrigation season and compared to the weekly surface irrigation water volumes allocated. Although the assessment of adequacy of allocations against the crop water demand (CWD) showed that the latter was much larger with 10-15% than allocated surface water for the entire area, with this difference being small at the beginning of the growing season.

The use of MOSES products during the irrigation management operations would help the water management authority to save water, especially during the winter season, leaving additional water available to meet requirements in spring and summer.
Characteristic radiocesium transport in temperature-stratified reservoirs and port-areas: Analysis by using a code, 3D-Sea-SPEC, developed for complex aquatic areas
Authors: Machida Masahiko , Yamada Susumu , Kurikami Hiroshi
Published: March 2020

A large amount of radioisotopes of Ceasium (Cs) was released into the surrounding environment by the accident of the Fukushima Dai-ichi Nuclear Power Plant (1F) occurred in 2011, and some of them fell into land and sea. Since Cs is an element inside a group of alkali metals, radioisotopes of Cs are strongly sorbed by soil and other particulate matters, especially clay, organic molecules, and polymers. Hence, full understanding of the movement of them in various environmental zones is strongly demanded. In order to reveal such transport processes of radiocesium in aquatic systems, we have so far developed a code, 3D-Sea-SPEC (3D Sea Simulation for Port and its Environmental Coast).  The code is composed of CFD based simulation solvers using LES scheme and aimed especially for analysis of complex aquatic zones like reservoirs and port areas. In this presentation, we give an overview of 3D-Sea-SPEC and show the technical improvements in realizing the water temperature stratification commonly seen in reservoirs and port areas under strong sun radiation in summer season. Next, we actually apply the improved code to a typical reservoir and a port area around 1F site, and demonstrate characteristic behaviors of the suspended sediment-sorbed radiocesium.
Radial thermo-chemical structure beneath Western and Northern Pacific inferred from seismic waveform inversion
Authors: Deschamps Frederic , Konishi Kensuke , Fuji Nobuaki , Cobden Laura
Published: March 2020

The Earth’s deep mantle seismic structure is dominated by two large low shear-wave velocity provinces (LLSVPs) located beneath Africa and the Pacific. These structures have been observed by many studies and data sets, but their nature, purely thermal or thermo-chemical, is still debated. Due to trade-off between temperature and composition, maps of shear-wave velocity anomalies (dlnVS) alone are unable to discriminate between purely thermal and thermo-chemical hypotheses. Seismic shear-wave attenuation, measured by the quality factor QS, strongly depends on temperature and may bring additional information on this parameter, allowing to resolve the trade-off between temperature and composition. Here, we invert seismic waveform data jointly for radial models of dlnVS, and QS at two different locations beneath the Pacific, and from a depth of 2000 km down to the core-mantle boundary (CMB). At the Northern Pacific (NP) location, sampling a region around 50º N latitude and 180º E longitude, around VS and QS remain close to the PREM values, representing the horizontal average mantle, throughout the investigated depth-range, with dlnVS ~ -0.1% and QS ~ 300 (compared to QPREM = 312). At the Western Pacific (WP) location, sampling the western tip of the Pacific LLSVP and the Caroline plume, both VS and QS are substantially lower than PREM. Importantly, dlnVS and QS sharply decrease in the lowermost 500 km, from -0.6 % and 255 at 2500 km, to -2.5% and 215 close to the CMB. We then show that WP models cannot be explained by thermal anomalies alone, but require excess in iron of 3.5 to 4.5 % from the CMB up to 2600 km, and about 0.4 to 1.0 % at shallower depths. This later enrichment may be due to the entrainment of small amounts of the Pacific LLSVP material by the Caroline plume. The values of QS we observe give an estimate of the temperature anomalies, around 300-400 K close to the CMB, and 150 K at shallower depths. By contrast, NP models may have a purely thermal origin and can be explained by a temperature excess of about 50 K.
Seismoacoustic Monitoring of Underground Explosions at Redmond Salt Mine, Utah, United States
Authors: Downey Nathan , Albert Sarah , Bowman Daniel
Published: March 2020

Underground blasting within an extensive tunnel complex occurs as part of regular operations at Redmond Salt Mine, located in central Utah, United States. During the period of October 2017 – July 2019, we monitored these explosions using seismic and infrasound sensors. The experiment recorded approximately 1000 mining-related blasts as well as several hundred small earthquakes that naturally occur in the monitoring region at source to receiver offsets of 3-25 km. The data collected early in the experiment allow us to explore the characteristics of infrasound signals generated in subterranean tunnels, which show a variety of interesting characteristics, including components related to the structure of the underground tunnel complex, and a time-varying propagation efficiency. We present analyses that attempt to explain these properties. In addition, the data collected during the experiment allow us to test location algorithms at local distances by comparing computed locations with those taken from ground-truth logs. Finally, comparison of the tectonic and explosion signals allows us to examine possible discrimination methods that will effectively differentiate explosions from earthquakes at local distances.
Multi-Dimensional Information Modelling Method for Underground Tunnel Spaces
Authors: Heikkilä Rauno , Hopia Jorma , Rauhala Anssi
Published: March 2020

A study of Multi-Dimensional information modelling of underground tunnel spaces is introduced. As a reference model an international  standard of Building Information Modelling (BIM) supported by Building Smart is used. Specific Finnish guidelines for infrastructures including tunnels are used. As experimental case underground Pyhäsalmi Mine on North Finland was used. Three selected tunnel at level of 660 meter were used. The tunnels were measured using advanced 3D laser scanning technologies as well as photogrammetric imaging. Different examples of tunnel information models were created and analysed. Recommendations for future work how to develop tunnel information modelling towards more and more information rich  Multi-Dimensional information models are suggested.
Intrinsic non-uniqueness of the acoustic full waveform inverse problem
Authors: Capdeville Yann , Lyu Chao , Al-Attar David , Zhao Liang
Published: March 2020

In the context of seismic imaging, the full waveform inversion (FWI) is more and more popular. Because of its lower numerical cost, the acoustic approximation is often used, especially at the exploration geophysics scale, both for tests and for real data. Moreover, some research domains such as helioseismology face true acoustic medium for which FWI can be useful. In this work, we show that the general acoustic inverse problem based on limited frequency band data is intrinsically non-unique, making any general acoustic FWI impossible. Our work is based on two tools: particle relabelling and homogenization. On the one hand, the particle relabelling method shows it is possible to deform a true medium based on a smooth mapping into a new one without changing the signal recorded at seismic stations. This is a potentially strong source of non-uniqueness for an inverse problem based a seismic data. Nevertheless, in the elastic case, the deformed medium loses the elastic tensor minor symmetries and, in the acoustic case, it implies density anisotropy. It is therefore not a source of non-uniqueness for elastic or isotropic acoustic inverse problems, but it is for the anisotropic acoustic case. On the other hand, the homogenization method shows that any fine-scale medium can be up-scaled into an effective medium without changing the waveforms in a limited frequency band. The effective media are in general anisotropic, both in the elastic and acoustic cases, even if the true media are isotropic at a fine scale. It implies that anisotropy is in general present and needs to be inverted. Therefore, acoustic anisotropy can not be avoided in general. We conclude, based on a particle relabelling and homogenization arguments, that the acoustic FWI solution is in general non-unique. We show, in 2-D numerical FWI examples based on the Gauss-Newton iterative scheme, the effects of this non-uniqueness in the local optimization context. We numerically confirm that the acoustic FWI is in general non-unique and that finding a physical solution is not possible.
Abstract numbers and algebra in PETSc
Authors: May Dave , Katz Richard
Published: March 2020

Scientific computing related to solving partial differential equations (PDEs) frequently employ both real and complex numbers, consequently computation libraries such as PETSc provide support for these number types and their associated algebra. Other “exotic” number types such dual numbers, hyper-dual numbers and intervals are also highly desirable in the context of solving PDEs, however these are seldom available within HPC linear algebra and or discretisation libraries.

I’m this presentation I will summarise several exotic number types and discuss some of their potential uses when solving: linear PDEs, non-linear PDEs, discrete adjoint problems and PDE constrained optimisation problems. Using these as motivation, I will also describe how these exotic numbers can be supported within PETSc. The approach adopted is general (extensible), non invasive and allows users to select the particular number type representation at run-time. Moreover the general design is well suited to the characteristics of modern computational hardware and thus can efficiently exploit different forms of parallelism. Through a series of toy problems, the cost and performance of the exotic number implementations will be assessed.
Hotspots of change in major tree species under climate warming
Authors: Babst Flurin , Peters Richard L. , Wüest Rafel O. , Evans Margaret E.K. , Büntgen Ulf , Hacket-Pain Andrew J. , Pappas Christoforos , Kirdyanov Alexander V. , Klesse Stefan , Trotsiuk Volodymyr , Björklund Jesper , Axelson Jodi , Harvey Jill , Smith Dan , Zang Christian , Karger Dirk N. , Zimmermann Niklaus E.
Published: March 2020

Warming alters the variability and trajectories of tree growth around the world by intensifying or alleviating energy and water limitation. This insight from regional to global-scale research emphasizes the susceptibility of forest ecosystems and resources to climate change. However, globally-derived trends are not necessarily meaningful for local nature conservation or management considerations, if they lack specific information on present or prospective tree species. This is particularly the case towards the edge of their distribution, where shifts in growth trajectories may be imminent or already occurring.

Importantly, the geographic and bioclimatic space (or “niche”) occupied by a tree species is not only constrained by climate, but often reflects biotic pressure such as competition for resources with other species. This aspect is underrepresented in many species distribution models that define the niche as a climatic envelope, which is then allowed to shift in response to changes in ambient conditions. Hence, distinguishing climatic from competitive niche boundaries becomes a central challenge to identifying areas where tree species are most susceptible to climate change.

Here we employ a novel concept to characterize each position within a species’ bioclimatic niche based on two criteria: a climate sensitivity index (CSI) and a habitat suitability index (HSI). The CSI is derived from step-wise multiple linear regression models that explain variability in annual radial tree growth as a function of monthly climate anomalies. The HSI is based on an ensemble of five species distribution models calculated from a combination of observed species occurrences and twenty-five bioclimatic variables. We calculated these two indices for 11 major tree species across the Northern Hemisphere.

The combination of climate sensitivity and habitat suitability indicated hotspots of change, where tree growth is mainly limited by competition (low HSI and low CSI), as well as areas that are particularly sensitive to climate variability (low HSI and high CSI). In the former, we expect that forest management geared towards adjusting the competitive balance between several candidate species will be most effective under changing environmental conditions. In the latter areas, selecting particularly drought-tolerant accessions of a given species may reduce forest susceptibility to the predicted warming and drying.
Synthetic Study for Optimizing an Efficient Grid Size for MT and Long Period MT Measurements
Authors: Vetrov Anton , Erdogan Erhan
Published: March 2020

While the Ultra Wide-Band Magnetotelluric technology (10,000Hz - 50,000 seconds) covers AMT, MT and LP bends in simultaneously measured time series, many research and exploration projects use dedicated MT (300Hz to 10,000 seconds) or LP (10 seconds - 50,000 seconds) systems. This is usually dictated by available equipment or a traditional approach to deep target studies. Surface anomalies (up to 2-5km) formed by conductive mineral bodies or fault systems considered to be less important and are often completely ignored during deep lithospheric studies. The upper layers conductivity is being estimated and averaged over the whole survey area. As it is very well known, the Magnetotelluric sounding signal measured on the surface represents an apparent resistivity at a depth dependent on frequency and conductivity of averaged ground thickness above. This assumption works generally well in smoothly layered geology, but might integrate an error in estimations and inversions in more complicated situations. In our previous studies we observed an effect of an upward shift of anomalies obtained after inversion of smaller grid size data for long period measurements. This seems to happen when the localized 3D conductive bodies are becoming dominant over the average layer conductivity and it cannot be assumed as a homogeneous thickness. In this study, our intention is analysing the efficient grid size that would be effective for MT band and LP band surveys. To achieve our estimated results, we designed a geoelectrical model that would be typical for Canadian shields with different grid sizes for MT band signal and LP band signals. We did run inversions using ModEM and observed vertical fit of inversion results to an original model.
Development of an operational forecast verification system
Authors: Boumis Georgios , Twigt Daniel , Verkade Jan
Published: March 2020

Verification provides the answer to the question "How good is my forecast?". Knowing the quality of a forecasting system provides a necessary baseline for improvement of that quality. It also contributes to forecast informed decision making, as verification provides a baseline estimate of residual uncertainties. 

To monitor the quality of the forecasts produced by Deltares Global Flow Forecasting system, a prototype of an operational forecast verification system was developed. The verification system comprises various components including the Ensemble Verification System (EVS), the Deltares OpenArchive and the Delft-FEWS forecast production system. Relevant verification metrics are computed by the EVS, which are subsequently stored and displayed in the forecasting system. This will allow for robust, automated forecast verification, and the usage of this information during the real-time forecasting process.  

Future work on the system will include a post-processing routine which will cast the verification information in a format suitable for publication to both existing and prospective GLOFFIS clients. Over the years, the system's outcomes are expected to provide a significant contribution to the quality of the GLOFFIS forecasts. 

In parallel, the system is being applied to various other operational hydrological forecasting systems around the globe.
Disturbed forest affects the hydrological processes in a small mountain catchment
Authors: Juras Roman , Vystavna Yuliya , Hnilicová Soňa
Published: March 2020

Hydrological response covered by disturbed forest catchments are in a focus of hydrologist last decades, mainly because the connection with widespread droughts. In this study, we compare two mountain catchments in Šumava Mts. (Czech Republic), both with small glacial lakes. Plešné lake catchment is characterised by disturbed forest by a bark beetle calamity. Contrary, Čertovo lake catchment features with undisturbed forest. Both catchments have comparable geological, climate setting and origin forest types. Stable isotopes of water were used for determining the hydrological pathways and water residence time. The results show that the state of the forest significantly affects the water balance of the catchments, but the mean residence time seems to be independent on this. On the other hand, even small changes in water residence time are important for the solutes and nutrients transport in the catchments. The lakes are fed by surface and subsurface water originating from liquid precipitation in and mostly snow in winter. The isotopic analysis helps to understand how much the snow cover affects the water balance during the hydrological year in two catchments with different forest stands.
Extreme floods value distributions under recent global warming in Northern Italy, and new risk management policies. The project FLORIMAP
Authors: Galizzi Mattia , Rosso Renzo , Bocchiola Daniele
Published: March 2020

Flood risk in Italy is a wide-spread and never-ending issue. Traditional flood defense focused on making the river system “resistant” to flood events, possibly by flood-control structures including floodwalls, levees, dams and channels. These actions reduce the frequency of inundations, but they do not affect flooding effects, and associated impacts once the flood plain is inundated. In facts, structural flood defenses are designed and operated to accommodate floods not exceeding a given magnitude, as fixed by the original design. Thus, these engineering works are highly inefficient to cope with capacity-exceeding floods, the magnitude of which was fixed many years ago using poor data sets, and it is expected to increase with climate changes.

FLORIMAP (Smart FLOod RIsk MAnagement Policies), a project funded by Fondazione CARIPLO aims to revalue extreme floods distribution in the different homogeneous areas of northern Italy using regional approaches based upon recent data form the last three decades.

FLORIMAP will first cover open issues associated with the quantification of flood hazard and inundation risk, then it will assess human exposure and vulnerability, and combine these issues with strategies of communication and risk management, because risk communication is an important activity that can influence the flood risk management. Communication is the bridge between the technical and professional community, decision makers, elected officials, funding sources, and the public at large. The literature on risk communication and perception has highlighted that the understanding of the psychological perception of environmental risk is a crucial factor in order to foster the community resilience and to promote adaptive attitudes and behaviors.

Here, we present a preliminary assessment of updated extreme values distribution for the case study of Northern Italy hydrologically homogeneous regions. The results will be then compared against those obtained with previous dataset dating until 1970, to study the evolution of flood hazard and inundation risk under recent climate change. We then provide application of flood hazard, and risk for a case study area, and demonstrate modified hazard under recent climate change.

We then discuss implications for risk communication in the target areas, and provide suggestions for prosecution of the FLORIMAP project. 
Equation of state of the [Fe,Ni]3Si system at conditions relevant to small terrestrial planets
Authors: Jamieson Andrew , Vočadlo Lidunka , Wood Ian
Published: March 2020

The detailed composition of terrestrial planetary cores is still unknown. The nature of the ‘light element’ alloying with Fe-Ni in planetary cores can affect a large range of properties, such as its melting temperature and the stable crystal structures it exhibits. While geophysical and geodetic parameters of a planet can provide first order information, mineral physics can also be used to investigate the compositional space.

We present ab initio simulations on the [Fe,Ni]3Si system (at ~7wt% and 14wt% Ni) to determine stable crystal structures and thermoelastic properties at PT conditions relevant to smaller terrestrial planets (central pressure <45 GPa). This will allow for comparisons to be made to any future seismic profile of Mars (from InSight or otherwise), and other research on the [Fe,Ni]3[Si,S] system. The overall aim to produce a compositional model for the core of Mars and place it in the context of the evolution of planetary cores, including the state and structure of Mars’ core.
Classification of ligneous vegetation into Plant Functional Types for a dynamic reconstitution of Neolithic vegetation cover in Occitania Mediterranean seashores
Authors: Saqalli Mehdi , Cahierre Marianne , Peyron Odile , Azuara Julien , Combourieu-Nebout Nathalie , Sicre Marie-Alexandrine , Lespez Laurent
Published: March 2020

Formalizing the connections existing between socio-ecosystem components implies establishing the dynamical links between both societies and vegetation cover types along time and space. In order to synthesize knowledge of Mediterranean paleo-environments and populations, the MISTRALS PaleoMex program aims at developing a step by step multidisciplinary and spatialized model of the climate, vegetation and human implantations in the Mediterranean seashores of Occitania Province (France) during the Neolithic Eras. The first step is to reconstruct the vegetation covers in the absence of humans. For this, 95 tree and bush species known to have grown in the region in Neolithic times are considered, which combining present-time species, historical data and pollen sequences. These species are then grouped in Plant Functional Types (PFTs) according to their tolerance to three factors: the mean annual temperature, the pH and the soil water balance. Two clustering methods were first tested: HCA (Hierarchical Clustering Analysis) and k-means based on the species’ tolerance interval for each factors. The resulting PFTs were well-defined enough to statistically explain the total ecological variance but were misleading botanically speaking, by failing in identifying clearly well-known PFTs such as the pioneer groups. A third method was thus assessed based on group species’ overlap of their tolerance intervals. Only 80% of the total variance was explained but the resulting 8 PFTs are more representative of natural species associations including a well-identified pioneer species PFT. Further investigations may be pursued to reach a total of 11 PFT groups in order to explain 95% of the total local variance. This PFT stock will be assessed using a virtual spatialized cellular automaton model with a 1ha spatial resolution and seasonal timescale. Elevation, pedology and dynamic climatology for each season and hectare will allow deciphering the spatial and dynamic evolution of the vegetation cover as a localized repartition of these PFTs.
Impact of NASA’s ESTO SLI-T, IIP, and other R&D Investments on SLI program
Authors: Dabney Philip , Masek Jeffrey , Babu Sachidananda , Ghuman Parminder , Kardan Nahal
Published: March 2020

Over the past decade, the NASA Earth Science Technology Office (ESTO) has strategically invested funds in programs that have yielded substantial benefits to the Sustainable Land Imaging (SLI) program.

Some of these investments, such as the SLI-Technology (SLI-T) program were funded using SLI funds set aside to reduce the risks and costs for future SLI needs.  Other programs, such as Advanced Component Technologies (ACT), Instrument Incubator Program (IIP), Advanced Information Systems Technology (AIST), and In-Space Validation of Earth Science Technologies (InVEST), address the broader Earth Science Land Imaging needs with direct benefit to SLI. 

This paper will highlight the relevant programs and indicate the ways that they have enabled and will enable the short and long-term SLI program needs and budgetary constraints.  Driving requirements and the ways these are satisfied with each components or system will be presented. 

Example data that demonstrates the performance of these new concept demonstrations will be shown.
Discriminating biomass and soil water content with proximal gamma-ray spectroscopy
Authors: Mantovani Fabio , Albéri Matteo , Bottardi Carlo , Chiarelli Enrico , Raptis Kassandra Giulia Cristina , Serafini Andrea , Strati Virginia
Published: March 2020

The exceptional capabilities of proximal radiometric measurements to estimate Soil Water Content (SWC) have recently been proven effective for precision farming applications. The water contained in the growing vegetation (i.e. Biomass Water Content, BWC) attenuates the terrestrial gamma signal acquired by a permanent station in a crop field and it represents the most relevant source of systematic bias. In the perspective of employing proximal gamma-ray spectroscopy for automatic irrigation scheduling, the Biomass Water Content (BWC) correction is mandatory for assessing crop water demand and for a sustainable use of water.

In this study we model the time dependent gamma signal attenuation due to BWC and we demonstrate that the SWC estimated through the corrected spectrometric data during a crop life-cycle agrees on average within 4% with the measurements obtained by gravimetric sampling campaigns. A reliable Monte Carlo simulation of the gamma photon generation, propagation and detection phenomena permits to evaluate the shielding effect due to the linear increase of BWC associated to stems, leaves and fruits of the tomatoes during their crop life-cycle. Compared to a SWC gamma estimation in the case of bare soil, the percentage overestimation δ is linearly correlated with the thickness of a biomass equivalent water layer (Tk) as δ (%) = 9.7 · Tk (mm), with a coefficient of determination r2 = 0.99.

Generalizing this approach, we can conclude that the plant growth curve is a fundamental input for correcting the SWC estimates in proximal gamma-ray spectroscopy via Monte Carlo simulation, in the perspective of filling the gap between punctual and satellite soil moisture measurements using this technique.
Anisotropy in soft rocks
Authors: Leuthold Julia , Gerolymatou Elina , Triantafyllidis Theodoros
Published: March 2020

In this work, the mechanically induced compaction process in highly porous rocks is studied with experimental investigations and constitutive modeling. The focus of the study is on the influence of the inherent anisotropy on the mechanical properties. From a practical point of view, such behavior is of particular interest when considering reservoirs in soft, porous rocks. The reduction in pore pressure, which is linked to the production, leads to the possibility of compaction in the vicinity of the borehole. One effect is the risk of the loss of stability or of increased sand production. Another is the reduction of the permeability locally. The probability of such occurrences and the magnitude of such effects is currently under debate.

Although the formation of compaction bands in porous rocks has already been investigated in several studies, both in the laboratory and in situ, the extent data about the influence of the inherent anisotropy on the mechanical properties of porous rocks is limited. Baud et al. [1] documented an influence of the orientation of the bedding plane on the mechanical behavior of Diemelstadt sandstone and Louis et al.  [2] documented an influence of the bedding plane on the formation of discrete and continuous compaction bands in Rothbach Sandstone.

On the basis of an extensive experimental program of triaxial and isotropic compression, triaxial extension tests as well as investigations with ultrasonic pulse method, the mechanical behavior of a highly porous rock (Maastricht Calcarenite) is analyzed with a special focus on the formation of compaction bands. The test program is performed with samples cored under different inclinations to the bedding plane to study the influence of the inherent anisotropy on the mechanical properties.

Based on the experimental results, the applicability of a constitutive model for the description of the mechanical properties is tested. Furthermore it is examined how the inherent anisotropy may be considered in the constitutive model and different approaches are discussed.

For the numerical simulation a nonlocal model is suggested to simulate the formation of compaction bands. Finally, conclusions are drawn and an outlook on experimental investigations of the influence of compaction banding on the hydraulically properties is given.

 

[1]P. Baud, P. Meredith und E. Townend, „Permeability evolution during triaxial compaction of an anisotropic porous sandstone,“ Journal of Geophysical Research, May 2012.

[2]L. Louis, P. Baud und T.-f. Wong, „Microstructural Inhomogeneity and Mechanical Anisotropy Associated with Bedding in Rothbach Sandstone,“ Pure and Applied Geophysics, July 2009.

 
Isotopic equilibrium between precipitation and water vapor in Northern Patagonia and its consequences on δ18Ocellulose estimate
Authors: Penchenat Tiphaine , Vimeux Françoise , Daux Valérie , Cattani Olivier , Viale Maximiliano , Villalba Ricardo , Srur Ana , Outrequin Clément
Published: March 2020

Modelling of the oxygen isotopic composition (δ18O) of tree-ring cellulose rely on the isotopic equilibrium assumption between the atmospheric water vapor and the tree source water, which is frequently assimilated to integrated precipitation. We explore the veracity of this assumption based on observations collected (δ18O of rain, rivers, leaves, tree-rings) or monitored (δ18O of water vapor) during a field campaign in Río Negro province, Argentina, in late summer 2017 (February-March). We examine, firstly, how the δ18O of water vapor deviate from the equilibrium with precipitation and, secondly, what is the impact of the isotopic equilibrium assumption on the calculation of the isotopic composition of tree-ring cellulose.

For oxygen, the isotopic disequilibrium between rain and vapor range between -2.0 and 4.1‰. Rain drops re-evaporation during their fall, evaporation of soil water and vegetation transpiration (resulting in transpired water accounting for 14 to 29% of ambient water vapor) could produce this disequilibrium. The small value of the disequilibrium at the study site is likely due to the high level of relative humidity (from 70 to 96%) favoring the isotopic diffusive exchanges between the two water phases and thus promoting the isotopic equilibrium.

A perfect agreement between observed and calculated isotopic composition of cellulose is obtained if the source water is assumed to be in isotopic equilibrium with the measured water vapor. This hypothetical source water has a significantly higher δ18O than the expected averaged isotopic composition of precipitation over the growing period or than the groundwater (river value). The veracity of the hypothesis of the isotopic equilibrium between water vapor and source water in tree-ring paleoclimate studies is discussed in light of these results.
Robust extreme value analysis: the bulk matching method
Authors: Kwasniok Frank
Published: March 2020

Traditional extreme value analysis based on the generalised ex-
treme value (GEV) or generalised Pareto distribution (GPD) suffers
from two drawbacks: (i) Both methods are wasteful of data as only
block maxima or exceedances over a high threshold are taken into ac-
count and the bulk of the data is disregarded. (ii) Moreover, in the
GPD approach, there is no systematic way to determine the threshold
parameter. Here, all the data are fitted simultaneously using a gener-
alised exponential family model for the bulk and a GPD model for the
tail. At the threshold, the two distributions are linked together with
appropriate matching conditions. The model parameters are estimated
from the likelihood function of all the data. Also the threshold param-
eter can be determined via maximum likelihood in an outer loop. The
method is exemplified on wind speed data from an atmospheric model.
An attempt to reconstruct central and eastern Iranian ophiolite puzzle
Authors: Lom Nalan , Qayyum Abdul , van Hinsbergen Douwe J.J.
Published: March 2020

Iran is a mosaic of continental blocks that are surrounded by Palaeo-Tethyan and Neo-Tethyan oceanic relics. Remnants of the ophiolitic rock assemblages are exposed around the Central Iranian Microcontinent (CIM), discretely along the Sanandaj-Sirjan Zone and in Jaz-Murian. The Present-day “ring” distribution of the Iranian ophiolites is not straightforwardly explained by a simple subduction zone architecture. One of the key features to solve the Iranian puzzle is the CIM which is surrounded by Sabzevar ophiolites in the north (99-77 Ma), Birjand-Nehbandan ophiolites in the east (~110 Ma) and Inner Zagros ophiolites in south-southwest (~103-94 Ma). The CIM consists of three major fault bounded sub-blocks, from east to west, Lut, Tabas, and Yazd. They represent an Atlantic-type continental margin that began rifting in Permo-Triassic as a result of opening of Neotethys Ocean. Subsequent convergence in Cretaceous to Paleogene time close the ocean basins around the CIM and emplaced the ophiolites onto the passive margins. Neogene Arabia-Eurasia collision induced replacement structures e.g., strike‐slip reactivation of normal faults that were associated with major block rotations.

We aim to kinematically restore the opening and closure history of the ocean basins found as ophiolitic relics around the CIM. Key in our analysis is the Doruneh and Great Kavir faults of Central Iran that continues into northern Afghanistan as the Herat Fault. Present-day GPS velocity vector measurements and deformation pattern show a NE-SW orientated shortening in Iran. Structural analysis of the Doruneh Fault indicates slip sense inversion before ~5 Ma. This observation is consistent with the deactivation of the dextral Herat Fault. Pre-Pliocene dextral movement in excess of 500 km along the Doruneh and Great Kavir faults may kinematically accommodate a major counter-clockwise rotation (~65o) of the CIM since the late Jurassic that has been inferred based on previous palaeomagnetic studies. This enables the transport of the Jandaq ophiolite from Aghdarband in the north to Anarak region of Central Iran and, duplication of curved Birjand-Nehbandan ophiolites in Sistan suture. If correct, this may imply that the closure history of the Central Iranian basins is directly connected to the large-scale Cretaceous to Paleogene extrusion tectonics in western Tibet and Hindu Kush regions. This preliminary study shows restoration of the post-Mesozoic deformation is essential to reconstruct the suture zones and pre-collisional setting in Iran, Afghanistan, and Pakistan.
Traceability in isotope ratio measurements: the role of data analysis
Authors: Meija Juris
Published: March 2020

Isotope ratios offer countless applications but almost as a rule precision measurements are required. Making use of such measurements involves comparison of the results between the laboratories which, in turn, requires international primary standards. Much less appreciated is the role of data analysis and measurement models. This presentation will feature a variety of examples of stable isotope ratio measurements, including light and heavy elements with examples from the redefinition of the kilogram, lead-lead dating, and carbon isotope delta reference scales, showing that choices on how we interpret and model our measurements can affect the traceability and comparability of isotope ratio measurements. The challenge is therefore for the analysts to recognize data analysis practices as a natural part of the measurement.