bluuebunny/crossref_metadata_2025 huggingface dataset:
Applying Solar Wind Observations to the IPIM Ionospheric Model
Authors: Thomas Simon , Blelly Pierre-Louis , Marchaudon Aurélie , Eisenbeis Julian , Bird Samuel
Published: March 2021

The IRAP Plasmasphere Ionosphere Model (IPIM) is an ionospheric model which describes the transport equations of ionospheric plasma species along magnetic closed field lines. The previous iteration of IPIM used some basic models to provide estimations of the solar wind conditions and associated motions of plasma and precipitation within the ionosphere as input. In this presentation, we discuss developments to IPIM as part of the EUHFORIA project, to consistently observe space weather conditions from the Sun to the Earth’s surface. The developments of the model include using in-situ solar wind observations from the OMNI data set, ionospheric radar data of plasma motions from the Super Dual Auroral Radar Network (SuperDARN), and the Ovation model of auroral precipitation, as inputs to the model. We compare the new version with the former version and ionospheric observations to explore the differences observed by including these data within the model. We present some new results using this new version of the model to explore the ionosphere’s response to solar wind transient events such as high-speed streams and coronal mass ejections.
Overturning Variations in the Subpolar North Atlantic in an Ocean Reanalyses Ensemble
Authors: Baker Jonathan , Renshaw Richard , Jackson Laura , Dubois Clotilde , Iovino Dorotea , Zuo Hao
Published: March 2021

The ocean’s Atlantic Meridional Overturning Circulation (AMOC) has a significant influence on global climate through its meridional transport of heat and carbon. Deep water formation occurring in the subpolar North Atlantic is an essential component the AMOC. Understanding the nature and causes of its multidecadal variation at these high latitudes is critical to more accurately predict future changes. We analyse the subpolar overturning in an ensemble of eddy permitting ¼ degree global ocean reanalyses, restrained by observations and historical forcings, over the period 1993-2018. This overturning transport is validated against the continuous measurements obtained along the Overturning in the Subpolar North Atlantic Program (OSNAP) mooring array since 2014. The ability of each reanalysis to capture the observed changes in the overturning will be determined, providing confidence in their ability to simulate changes prior to the availability of OSNAP, and exposing their limitations. We analyse the eastern and western sections of the OSNAP array to determine the relative importance of the overturning along these sections and the temporal variability on various timescales. This research complements a previous study investigating changes in the subtropical Atlantic overturning using the same reanalyses ensemble which was shown to provide a good approximation to observations.
Marine electromagnetic imaging and volumetric estimation of large-scale freshwater plumes offshore Hawai'i
Authors: Attias Eric , Constable Steven , Sherman Dallas , Ismail Khaira , Shuler Christopher , Dulai Henrietta
Published: March 2021

Submarine groundwater discharge (SGD) is a flow of cold and buoyant freshwater from the seafloor the ocean surface. Because SGD contains carbon, nutrients, metals, and green-house gases, it changes the oceanographical and biochemical properties of coastal waters. Therefore, SGD is an important phenomenon that governs hydrological cycles at the land-to-ocean transition zone. Due to the high spatial distribution and variability of SGD at the ocean surface, it is nontrivial to map SGD seep location and fluxes using traditional oceanographic methods. Here, we present electromagnetic imaging of large freshwater plumes in high-resolution, offshore west of Hawai‘i island. Our electrical resistivity models detect multiple vertical freshwater plumes (SGD point-sources) as well as spatially distributed surface freshwater, extending to a distance of ~3 km offshore Hawai‘i. Plume-scale salinity distribution indicates that these plumes contain up to 87% of freshwater. Thus, a substantial volume of freshwater occupies Hawaiian water column plumes. Our findings provide valuable information to elucidate hydrogeologic and oceanographic processes affecting biogeochemical cycles in coastal waters worldwide. This is the first study to demonstrate the marine electromagnetic method’s capability to image and delineate freshwater plumes from the seafloor to the ocean surface.

Keywords: Freshwater Plumes, SGD, Hawai'i, Surface-towed CSEM, high-resolution 2D electrical imaging.   
Vegetation dynamics in a climate change hotspot: trend analysis in a Spanish dehesa
Authors: Reddig Fabian , Bareth Georg , Bogner Christina
Published: March 2021

      Introduction The Mediterranean region has been identified as a hotspot of climate change characterized by a large tree mortality. Extended drought periods, shifts in rainfall patterns, and increasing water stress are probably the main drivers. Especially holm (Quercus ilex L.) and cork oak trees (Quercus suber L.) in high-value and nature-based agroforestry systems (in Spain known as dehesa) have multiple positive effects on the microclimate, carbon storage, erosion prevention, increase of soil water content, and soil nutrient concentration, for example. With their positive effect on wind velocity, they are also considered the last natural barrier protecting the Iberian Peninsula and Central Europe from desertification processes advancing from North Africa.
     Objective We assume that wrong management, biotic causes like pests and diseases, and especially water stress are responsible for a decreased resilience of oak trees. Our goal was to analyse the vegetation dynamics with the help of the Normalized Difference Vegetation Index (NDVI) time series as an indicator for greenness and vitality. In particular, we focused on the trend of NDVI over about two decades.
    Material and Methods We have selected eight plots (250 m x 250 m) with different topographical conditions and analysed an 18 years long NDVI time series (2003 - 2020) from MODIS (MYD13Q1). To extract the trend, we decomposed the time series into trend, seasonal component, and the high-frequency remainder. Subsequently, we did the Mann-Kendall test on the trend component to determine whether the trend is significant. Since environmental time series are rarely linear or stationary, many statistical decomposition methods are not suitable to produce physically meaningful results. Therefore we used the data-driven method Complete Ensemble Empirical Mode Decomposition with adaptive Noise (CEEMDAN) by Torres et al. 2011.
     Results Depending on the topographical conditions of the plot, we were able to extract different NDVI trend signals from the time series. The NDVI values on the north-facing plots were larger than on the south-facing plots. The extracted trends were positive and significant (p <0.01). The seasonal component corresponded to the expected annual cycle.
      Conclusion In order to assess vegetation dynamics, NDVI time series can be regarded as a good starting point, although one indicator alone does not allow to make final conclusions about vegetation changes. The purely data-driven decomposition method CEEMDAN avoids strong assumptions about the shape of the trend.
Stable isotope geochemistry of Oxygen and Hydrogen: A case study of the Satluj River Basin, India  
Authors: Jahan Akhtar , Khan Mohd Usman , Rai Nachiketa , Maurya Abhayanand Singh , Kumar Sudhir
Published: March 2021

Stable isotope analysis of hydrogen and oxygen is one of the important methods used to model the hydrological cycle. Oxygen and hydrogen isotopic investigation of river water, its tributaries, and groundwater of its catchment from the Satluj basin was undertaken to estimate the contributions of the main sources comprising discharge during major periods throughout a hydrologic year.

Estimation of the snow/glaciers melt contribution is also very important for tracing the sources and processes regulating the flow from the provenance and reservoirs in the context of global warming, for estimating flood flow, and for other water resource development activities in large parts of the Indian subcontinent. Water samples were collected during the non-monsoon season at increasing altitudes. In this work, in addition to stable isotopes, we also assessed the water quality using various physicochemical parameters and geochemistry of the water.

From isotopic analyses of river water samples, the mean value of the δ18O was found to be ~ -13‰, and the mean value of δD was found to be~ -85‰. For the samples from Satluj tributaries, the mean value of the δ18O was ~ -11‰, and the mean value of δD was ~ -69‰. A mean value of -8.4‰, was found based on the δ18O measurements of the groundwater samples, while the average δD value was found to be ~ -55‰.

For the mainstream and tributary, LWL, y = 8.2604x +20.208, and range of d-excess (>10‰) and y = 8.2079x + 22.182 and d-excess > 10‰ indicates a system recharged by sources of recycled moisture derived from continental sources in addition to monsoonal climates. For the groundwater data, the slope is 6.7, and d-excess ranges from 7‰ to 17‰. These observations are suggestive of the monsoonal source of Indian Ocean precipitation that has experienced significant evaporation during the non-monsoon season.

Our new data clearly shows that the surface water whether mainstream, tributary, and groundwater isotopes are homogenized from regional trends in precipitation, modified by evaporation, and are thus greatly influenced by latitude, elevation, and patterns of climate.

 
Epidemics, climate change and natural hazards: Impacts and risk perceptions under COVID-19
Authors: Di Baldassarre Giuliano , Mondino Elena , Raffetti Elena
Published: March 2021

Epidemics, climate change and natural hazards are increasingly affecting humankind and are plausibly re-shaping the way in which people perceive multiple risks. Here we integrate epidemiological, policy, climate and natural hazard data with the results of two waves of nationwide surveys in Italy and Sweden. These were conducted in two different phases of the COVID-19 pandemic corresponding to low (August 2020) and high (November 2020) levels of infection rates. We investigate the interplay between negative impacts and public perceptions of multiple hazards including epidemics, floods, droughts, wildfires, earthquakes, and climate change. Similarities and differences between Italy and Sweden allow us to investigate the role of policy, media coverage, and direct experience in explaining public perceptions of multiple hazards. The way in which people think about epidemics, for example, is expected to have been substantially influenced by the COVID-19 pandemic that has severely affected both countries, but to which the Italian and Swedish authorities responded differently. Indeed, we found that epidemics are perceived as less likely and more impactful in Italy compared to Sweden. In addition, when multiple hazards are considered, people are more worried about risks related to recently occurred events. This is in line with the cognitive process known as availability heuristic: individuals assess the risk associated with a given hazard based on how easily it comes to their mind. Furthermore, for the majority of hazards, we found that in both countries women and younger people are generally more concerned. These new insights about the interplay between multiple hazards and public perceptions can inform the development of sustainable policies to reduce disaster risk while promoting public health.

 
The effects of climate on corn price movements in the United States
Authors: Deng Qiaoyu , Sun Xun
Published: March 2021

Corn is the 1st economic field crop in the world, whose price stability guarantees sustainable and equitable food security. Most previous farm commodity price prediction model only focus on detecting the autoregression of historical transaction, while ignoring other factors. For agricultural commodities, different climate condition leads to different harvest situation, thus bringing volatility to prices. Therefore, it is reasonable to propose a method based on climate indices to measure the degree of their influence on price fluctuation.

A multiple regression model is developed for predicting corn price movements at the nation level. The June-September season is selected to target the essential growing stages of corn which are especially sensitive to drought, high temperature stress and water stress. In order to describe the movements of price, the price difference between June and September is chosen as the dependent variable. Daily climate data are obtained from PRISM which integrates both satellite and meteorological station observation data, and monthly price data are sourced from USDA. 39-year trend from 1981-2019 is explored to construct a predictive model. The results show that the accuracy of predicting up and down of price is 85%. Specifically, temperature in July has an identifiable effect on price movements which explains 36.99% price variation. These results imply that during the key growing period, climate indices occupy an important position on improving crop price forecast ability.
Drag coefficients of large instream wood – mystery or science?
Authors: Schnauder Ingo
Published: March 2021

Drag coefficients convert flow velocity into the force exerted on a body and hydraulic head loss. They spatially integrate all properties of a given configuration into one single parameter. Therefore, drag coefficients are widely used in engineering, including environmental flow applications such as large wood log. However, the scatter in drag coefficients reported from previous studies clearly indicate that universality is no longer given and predictions underlie large uncertainties. Deeper analyses are mostly restricted due to insufficient hydraulic data – which in many studies is simply the discharge and the derived cross-sectionally averaged velocity.

It is obvious, that the ‘ideal’ drag coefficients from infinite and low-turbulence wind tunnel studies with the iconic cD = 1.1 for the subcritical regime (104 < Re < 105) do not apply anymore. Instead, disturbances play a major role. For large wood, these are typically (i) blockage of the finite river cross-sectional area, (ii) the proximities of the bed below and the free-surface above, (iii) interaction with the free-stream turbulence, (iv) wake interference and (v) 3D-effects such as free ends of the cylindrical or channel aspect ratio.

To search for a more robust predictive scheme, we started flume experiments with horizontal cylinder configurations and measured the flow field in vertical profiles as well as the overall drag. First results shifted our emphasis from drag to velocity coefficients like the ones used in energy and momentum equations to account for non-uniformity. This seems reasonable, both because of the the squared represention of velocity in the drag term and because of the significant non-uniformities in large wood constellations.
Cenozoic subsidence characteristics and evolution at a hyper-extended continental margin: Revealed by 3D high-resolution seismic data from the Baiyun Sag, northern South China Sea
Authors: Fang Penggao , Ding Weiwei , Zhao Yanghui
Published: March 2021

The hyper-extended continental crust in the passive margins, which recording the extensional processes in relation with the breakup of continental crust and lithosphere as well as the onset of seafloor spreading, have been widely recognized and studied at present-day rifted margins. The Baiyun Sag (BS) represents one of the hyper-extended continental marginal basins with a sharply thinned continental crust from 25 km to 7 km over a ~ 50 km distance along the Northern South China Sea, which experienced syn-rift to post-rift during the Cenozoic. Although the Cenozoic infill of the BS has been extensively described, newly acquired 3D seismic profiles revealed a thick succession (up to 10 km) with thicken syn-rift but relatively thin post-rift strata particularly well imaged in the central part. The imaged succession is controlled by the interaction between well-developed detachment systems and depth-dependent stretching, resulting in different and complex subsidence architecture. Attempts had been made to quantify the subsidence in the BS, while most studies were only carried out in a limit set with one or few 2D seismic sections and generally focused on the post-rift subsidence but ignoring that in the syn-rift stage. As result, we investigate the interaction between spatial-temporal distributions of tectonic subsidence from continent break-up to post-rift and the evolution of hyper-extended rift systems along the relatively young age passive margins.

In this presentation we analyze the vertical and horizontal motions of tectonic subsidence and sedimentary processes with integrated high-quality multi-channel seismic profile grid data (~30 seismic sections). This study enables us to 1) interpret the main unconformities and analyze the depth conversion of the BS, 2) reconstruct the tectonic subsidence from syn-rift to post-rift, 3) provide a 3D subsidence analysis unravelling the temporal and spatial architecture of Cenozoic infill of the BS. The main objectives of this contribution is to discuss the possible mechanisms accounting for the origin and subsidence at the BS, reveal its interrelationships with magmatic activities, and explore the style of rift to post-rift subsidence pattern at a hyper-extended continental margin.
Influence of the filter properties in the diffusive transport of ions through a bentonite. Sensitivity analysis
Authors: Cabrera Virginia , López-Vizcaíno Rubén , Yustres Ángel , Navarro Vicente
Published: March 2021

The deep geological repository concept for spent nuclear fuel considers many safety elements. Among them, compacted bentonite has been selected as the primary engineering barrier between the encapsulated radioactive waste and the host rock. Thermo-hydro-mechanical behaviour of this material has been studied in detail from an experimental and numerical point of view. Furthermore, the study of chemical behaviour has become very important, both for the evaluation of the transport of species through the clay matrix and for the evaluation of their coupling to other physico-chemical phenomena.

Generally, to conduct these types of studies, infiltration tests through compacted bentonite columns are carried out using an experimental setup composed of common parts: (i) porewater and infiltration water reservoirs, (ii) pumping devices and (iii) a confined sample of bentonite. The infiltration/output solutions are injected/extracted through filters positioned in the top/bottom of the sample. The results obtained in these tests are strongly influenced by the properties of these filters. For this reason, it is very important how the chemical species and the fluid are transported in the filters to correctly interpret the experimental observations. The study presented in this work is framed in this context, in which a numerical sensitivity analysis of the transport properties and size of the filters has been conducted. For this purpose, a reactive transport model for bentonites (assuming this material as a double porosity media) formulated by the authors and fully implemented in the multiphysics platform, COMSOL, has been used to simulate a cation exchange-infiltration test in MX-80 bentonite defined in the “Chemical session” of the Task Force on Engineered Barrier Systems (EBS) organised by SKB AB. The results obtained depend on the tortuosity, porosity and thickness of the filters. These parameters have been estimated for the correct interpretation of the selected test.
First deployment of a 6-km long fiber-optic strain cable and a seafloor geodetic network, across an active submarine fault (offshore Catania, Sicily): The FOCUS experiment
Authors: Gutscher Marc-Andre , Royer Jean-Yves , Murphy Shane , Klingelhoefer Frauke , Barreca Giovanni , Gaillot Arnaud , Quetel Lionel , Riccobene Giorgio , Aurnia Salvatore , Jousset Philippe , Poitou Charles , Ciausu Viorel
Published: March 2021

For the first time, a 6-km long fiber-optic strain cable was deployed across an active fault on the seafloor with the aim to monitor possible tectonic movement using laser reflectometry, 25 km offshore Catania Sicily (an urban area of 1 million people). Brillouin Optical Time Domain Reflectometry (BOTDR) is commonly used for structural health monitoring (bridges, dams, etc.) and under ideal conditions, can measure small strains (10-6) along a fiber-optic cable, across very large distances (10 - 200 km), with a spatial resolution of 10 - 50 m. The FocusX1 expedition, (6-21 October 2020) onboard the R/V Pourquoi Pas? was the first experiment of the European funded FOCUS project (ERC Advanced Grant). We first performed micro-bathymetric mapping and a video camera survey using the ROV Victor6000 to select the best path for the cable track and for deployment sites for eight seafloor geodetic stations. Next we connected a custom designed 6-km long fiber-optic cable (manufactured by Nexans Norway) to the TSS (Test Site South) seafloor observatory in 2100 m water depth operated by INFN-LNS (Italian National Physics Institute) via a new Y-junction frame and cable-end module. Cable deployment was performed by means of a deep-water cable-laying system with an integrated plow (updated Deep Sea Net design Ifremer, Toulon) to bury the cable 20 cm in the soft sediments in order to increase coupling between the cable and the seafloor. The cable track crosses the North Alfeo Fault at four locations. Laser reflectometry measurements began on 18 October 2020 and are being calibrated by a 3 - 4 year deployment of eight seafloor geodetic instruments (Canopus acoustic beacons manufactured by iXblue) deployed on 15 October 2020. During a future marine expedition, tentatively scheduled for early 2022 (FocusX2) a passive seismological experiment is planned to record regional seismicity. This will involve deployment of a temporary network of Ocean Bottom Seismometers (OBS) on the seafloor and seismic stations on land, supplemented by INGV permanent land stations. The simultaneous use of laser reflectometry, seafloor geodetic stations as well as seismological land and sea stations will provide an integrated system for monitoring a wide range of slipping event types along the North Alfeo Fault (e.g. - creep, slow-slip, rupture). A long-term goal of the project is the development of dual-use telecom cables with industry partners.
The effects of the storm Gloria in Catalonia: The value of quick-response geological inventories as a tool for risk management
Authors: González Marta , Micheo Maria Jesus , Pinyol Jordi , Carles Maria Rosa , Pi Eulàlia , Vila Miquel , Roca Antoni
Published: March 2021

The storm Gloria was an exceptional episode of east storm occurred in the north and east of Spain from Sunday 19th to Thursday 23rd of January 2020. The impact was especially strong in the Mediterranean coast, causing the overflow of some rivers, abundant slope movements, cuts in the road and rail network, isolation of populations, and huge damage on the coastline.  It was classified as historical, not only because of the multiplicity of phenomena (wind, rain, snow, and waves) that happened simultaneously, but also because of the extension, affecting the entire Catalan territory. In order to have an overview of the effects of the storm in Catalonia, the Institut Cartogràfic i Geològic of Catalonia has carried out a quick response report (González et. Al., 2020), which has consisted of an inventory of the geomorphological impact and its consequences. The work carried out includes the production of post-event orthoimages of the coastal strip and some fluvial courses, a post-event field survey during the days immediately after, and a compilation of the information published in the media between 01/20/2020 and 02/18/2020. Also, a data collection campaign through online forms sent by email has been carried out, which provides more information of the sea gale effects, and validates and complete the preliminary inventory of slope movements. Thus, an inventory of slope movements has been obtained with a total of 352 documented landslides throughout the Catalan territory. In addition, a geomorphological mapping with the changes associated to river dynamics has been carried out, in two of the most affected sectors in NE Catalonia: the lower section of the Tordera river and the lower section of Ter river. This 1: 5 000 scale cartography, identify geomorphological elements from fluvial dynamics (active fluvial channels during the flood, active flood plain, erosion scarps of river banks, flow direction lines) and from coastal dynamics (washoverfans, coastal erosion and new creation stream-mouth bars). Finally, based on the analysis of the data collected, an estimate has been made of the impact that the storm Gloria has had on the territory, and how it has affected the different municipalities, in terms of damages and economic losses. The results of this quick response report allow (i) to have a geomorphological record of the storm extent in the short term, (ii) to provide basic information for the management and recovery of river areas, and (iii) to propose new strategies for geological risk management, among others.
Correcting position of delayed on-the-go field measurements by optimizing nearest neighbor statistics
Authors: Gonzalez Jimenez Alfonso , Pachepsky Yakov , Gómez Flores José Luis , Ramos Rodríguez Mario , Vanderlinden Karl
Published: March 2021

On-the-go field measurements of soil and plant characteristics, including yield, are commonplace in current Precision Agriculture applications. Yet, such measurements can be affected by positional inaccuracies that result from equipment configuration or operation characteristics (e.g. GPS antenna position with respect to sensor position) and delays in the data transmission, reception or logging. The resulting time and position lags cause a misfit between the measurements and their attributed GPS position.

In order to compensate for this effect a simple coordinate translation along the measurement direction is proposed, depending on the local velocity and a field- and measurement configuration-specific time lag, which is estimated by minimizing the average absolute difference between the nearest neighbors. The correction procedure is demonstrated using electromagnetic induction data with different spatial configurations and by comparing
variograms for corrected and non-corrected data.

Best results are obtained when overlapping measurements are available, obtained in opposite driving directions, while the worst results are found when no overlapping measurements exist or only those corresponding to headland turns. Further improvements in the nearest neighbor search algorithm, e.g. by imposing the search in adjacent measurement swaths are discussed. The results are valid beyond motorized soil sensing applications.

Acknowledgement
This work is funded by the Spanish State Agency for Research through grant PID2019-104136RR-C21 and by IFAPA/FEDER through grant AVA2019.018.
Evaluation of the Mechanical Strength of Disturbed Military Training Areas based on the Physical and Chemical Parameters of Soil
Authors: Vennik Kersti , Tõnutare Tõnu , Krebstein Kadri
Published: March 2021

Military training areas have to sustain the intensive usage of tracked and wheeled vehicles and the dismounted movement of soldiers. The periodic nature of training activities causes heavy loads, including a high number of loading repetitions on the soil; this makes the mechanical strength and recovery of soil a consequential issue. In many cases, the preparation of new training areas involves field preparations, e.g. earthmoving or deforestation activities that lead to serious disturbance of soil, especially its natural mechanical strength. The goal of this study was to investigate the potential methods to determine the conditions of previously disturbed military training areas. Soil measurements were carried out two years after deforestation works. Within this study, soil samples were collected and the mechanical strength of soil was determined in July and November 2020, with the aim to characterize soil conditions during dry and wet periods. Soil bulk density as well as cone penetrometer and dynamic cone penetrometer measurements were carried out.  In chemical parameters of soil, the total carbon content was measured as an indicator of uniformity by mixing organic matter in the soil surface (25 cm) layer. As the development of plant cover and especially its tight root system is very important for increasing the mechanical strength of soil, the content of plant available nutrients (P, K, Mg and Ca) was also measured. To evaluate the uniformity of blended upper soil layer, the soil was divided into 5 different layers of 5 cm thick each. The bulk density was determined for each layer. The chemical parameters of soil were determined for each layer separately and a diagram of element content in profile was created according to obtained results. This presentation will address the preliminary results of field measurements.
Deciphering the seismic and normal-force fluctuation signatures of debris flows: an experimental assessment of the effects of flow composition and dynamics
Authors: de Haas Tjalling , Aaberg Amanda , Walter Fabian , Zhang Zhen
Published: March 2021

Debris flows are gravity-driven mass movements that are common natural hazards in mountain regions worldwide. Previous work has shown that measurements of ground vibrations are capable of detecting the timing, speed, and location of landslides and debris flows. A remaining question is whether or not additional flow properties, such as grain-size distribution, flow depth, and impact stress can be inferred reliably from seismic data. Here, we experimentally explore the relation of seismic vibrations and normal-force fluctuations with debris-flow composition and dynamics. We show that seismic vibrations and normal-force fluctuations induced by debris flows are strongly correlated, and that both are strongly affected by debris-flow composition. We find that the effects of the large-particle distribution on seismic vibrations and normal-force fluctuations are substantially more pronounced than the effects of water fraction, clay fraction, and flow volume, especially when normalized by flow depth. We further show that for flows with similar coarse-particle distributions seismic vibrations and normal-force fluctuations can be reasonably-well related to flow depth, even if total flow volume, water fraction, and the size distribution of fines varies. Our experimental results shed light on how changes in large-particle, clay, and water fractions affect the seismic and force-fluctuation signatures of debris flows, and provide important guidelines for their interpretation.
Trends in heat stress over Europe over the 20th century
Authors: Kjellsson Joakim , Niebaum Nils , Pilch Kedzierski Robin
Published: March 2021

We investigate how European heat waves and their associated heat stress on humans have changed over the 20th century. We find that the heat stress has increased, even in regions where heat waves have not become warmer. As heat stress increases over wide areas of Europe there is also an increase in the total population affected by the heat stress. 

Heat waves pose a serious health risk to humans by reducing our ability to shed heat. We have studied the occurrence and intensity of heat waves as well as a heat stress index based on simplified wet-bulb globe temperature using data from ERA-20C reanalysis 1900-2010. Over the 110 years of data we find an overall warming of the air temperatures and dew point. The 98th percentile of both air temperature has increased by more than 1.5°C over large areas of Europe. 

We find an overall increase in heat wave days per year as well as an increase of air temperature during heat waves over most of Europe. As such, many densely populated areas exhibit increased heat stress during heat waves. For example, the mean heat stress during heat wave days over Paris has increased by one level, from “alert” in 1900-1930 to “caution” in 1980-2010. The fraction of the population exposed to heat waves has increased by 10%/century in central Europe and 25%/century over the Mediterranean. 

We find more heat waves during 1920 - 1950, which may be related to the positive phase of the Atlantic Multidecadal Variation (AMV). This suggests that the heat stress during European heat waves may also be influenced by internal climate variability, and large-ensemble model simulations may be used to disentangle the effects of natural variability and anthropogenic forcing.
Evaluating aromaticity changes with thermal stress at the single particle level for a suite of organic matter types from the Boquillas Shale (Texas, United States) via correlative Raman and reflection analyses
Authors: Jubb Aaron , Birdwell Justin , Hackley Paul
Published: March 2021

Geochemical, petrographic, and spectroscopic indices that vary with compositional changes in petroliferous organic matter (OM) during thermal maturation are key petroleum system parameters used to understand petroleum generation. In unconventional shale source-rock reservoirs, where multiple, highly dispersed OM types may be present in intimate contact with surrounding mineral phases, OM molecular composition (e.g., aromaticity) is especially useful for informing structure-reactivity relationships representative of different OM types. Here, we employ microscale, in situ, and correlative Raman and reflectance approaches to evaluate aromaticity evolution for a suite of OM types (i.e., liptinite, micrinite, solid bitumen, vitrinite, and inertinite) at the single particle level across an artificial thermal gradient. Our samples include a marginally mature (vitrinite reflectance ~0.5%) Late Cretaceous Boquillas Shale from south Texas, United States, and two hydrous pyrolysis (HP) residues following reaction of the raw Boquillas Shale sample at 300°C and 330°C for 72 hours. Our data indicate that: (i) liptinite, micrinite, solid bitumen, vitrinite, and inertinite particles exhibit different aromatic signatures in the raw shale sample and (ii) these OM types, with the exception of inertinite, effectively experience similar changes in aromatic structure with thermal advance. Data also reinforce the concept that reservoir temperature may be a secondary factor in controlling the molecular composition of inertinite. These findings inform a broader understanding of how different petroliferous OM types evolve throughout thermal reactions and further demonstrate that correlative Raman spectroscopy and reflection analyses, combined with careful organic petrography, can provide complimentary estimates of OM molecular composition and thermal maturity.
Role of viruses in biosphere
Authors: Sapunov Valentin
Published: March 2021

Presented work is synthesis of both literature data and own efforts on study of virus transduction and demography models. The aim would be considering of viruses and other sub-cell organisms as needful part of life on Earth basing on fundamental biology and ecology. It is important to understand the negative consequences for humanity and the biosphere of extreme outbreaks of dangerous viruses (Spanish flu, AIDS, etc.). Viruses were discovered by the Russian scientist D. Ivanovsky in 1892 and named "filtering virus". Having the size of a molecule, it passes freely through filters and masks. In the early twentieth century, the Russian scientist V. Vernadsky predicted the existence of a single information field of the biosphere. In 60-s of XX century was opened to the genetic code, which was uniform in all organisms (G. Korana, etc.). 70-ies the phenomenon of "horizontal transfer," i.e., transferability of information among all living organisms on the planet without a sexual process (B. McClintock, M. Golubovsky, etc.) was discovered. Some viruses (e.g. T4) are the most studied organisms on Earth due to its relative simplicity. The number of virus types is not estimated, but can be measured in millions. The number of virus individuals on the planet is estimated at 1039. Viruses are a necessary part of the biosphere. They create a "biological Internet" in which the information unity of organisms is ensured by the constant transfer of DNA sections between all organisms due to vires transduction. Viral epidemics are an example of co-evolution of higher and lower organisms. It temporarily reduces the number of individual species (for example, the number of people during the Spanish flu decreased by 17 million), but never threatens the existence of a particular species. Just as the medical fight against viruses reduces their population, but does not completely destroy them. The human immune system and the virus gene pool are also in a state of co-evolution. The temporary reduction in the number of the host organism of the virus is further compensated by increased immunity and a rise in the birth rate. Viruses activate the immune system of both individuals and humanity as a whole. Man needs them just as small wars are needed to maintain the combat capability of armies. Forecast of negative and positive consequences of virus reproduction is possible basing of modern mathematical ecology and genetics.
The melody of a failing peak – seismic constraints on rock damaging and stick-slip motion at the Hochvogel (DE/AT Alps)
Authors: Dietze Michael , Krautblatter Michael , Leinauer Johannes , Illien Luc , Hovius Niels
Published: March 2021

Large rock slope failures play a pivotal role in long-term landscape evolution and are a major concern in land use planning and hazard aspects. While the failure phase and the time immediately prior to failure are increasingly well studied, the nature of the preparation phase remains enigmatic. This knowledge gap is to a large degree related to challenges in collecting appropriate data in such high mountain terrain. Classic monitoring techniques provide detailed data but mostly of point character and only reflecting the surface expression of processes within the rock mass. Thus, the integral behaviour of a peak, at the surface and at depth remains elusive.

Here, we present results from a continuous multi-sensor seismic analysis of the Hochvogel summit, a 2592 m high Alpine peak, which is deemed to fail in the near future, as a 5 m wide and 40 m long crack is progressively opening and mobilising up to 260,000 cubic metres of rock. The seismic network consisted of up to seven sensors, installed during July--October 2018 (with 43 days of data loss). We develop and discuss proxy time series indicative of cyclic and progressive changes of the summit.

Modal analysis, horizontal-to-vertical spectral ratio data and end-member modelling analysis reveal diurnal cycles of increasing and decreasing coupling stiffness of the fragmented rock volume, due to thermal forcing. Relative seismic wave velocity changes mimic this pattern but also reveal the release of stress within the rock mass. At longer time scales, there is a superimposed pattern of stress evolution, which increases for five to seven days and suddenly drops within a few days, also expressed in an increased emission of short seismic pulses indicative of rock cracking. Our data provide essential first order information on an early stage of a large-scale slope instability, which evolves towards a catastrophic failure.
Evaluating the response of the diurnal range of surface and air temperature to evaporative conditions across vegetation types in ERA5 and FLUXNET data
Authors: Panwar Annu , Kleidon Axel
Published: March 2021

The diurnal variations of surface and air temperature are related but their different responses to evaporative conditions can inform us about land-atmosphere interactions, extreme events, and their response to global change. Here, we evaluate the sensitivity of the diurnal ranges of surface (DTsR) and air (DTaR) temperature to evaporative fraction, across short vegetation, savanna, and forests at 106 Fluxnet observational sites and in the ERA5 global reanalysis. We show that the sensitivity of DTsR to evaporative fraction depends on vegetation type, whereas for DTaR it does not. Using FLUXNET data we found that on days with low evaporative fraction, DTsR is enhanced by up to 20 °C (30 °C in ERA5) in short vegetation, whereas only by 8 °C (10 °C in ERA5) in forests. Particularly, in short vegetation, ERA5 shows stronger responses, which is attributable to a negative bias on days with the high evaporative fraction. ERA5 also tends to have lower shortwave and longwave radiation input when compared to FLUXNET data. Contrary to DTsR, DTaR responds rather similarly to evaporative fraction irrespective of vegetation type (8 °C in FLUXNET, 10 °C in ERA5). To explain this, we show that the DTaR response to the evaporative fraction is compensated for differences in atmospheric boundary layer height by up to 2000 m, which is similar across vegetation types. We demonstrate this with a simple boundary layer heat storage calculation, indicating that DTaR is primarily shaped by changes in boundary layer heat storage whereas DTsR mainly responds to solar radiation, evaporation, and vegetation.  Our study reveals some systematic biases in ERA5 that need to be considered when using its temperature products for understanding land-atmosphere interactions or extreme events. To conclude, this study demonstrates the importance of vegetation and the dynamics of the atmospheric boundary layer in regulating diurnal variations in surface and air temperature under different evaporative conditions.
Inventory and assessment of geoheritage in the Liguria region (Italy) within the framework of land management and development
Authors: Ferrando Andrea , Faccini Francesco , Poggi Flavio , Coratza Paola
Published: March 2021

 Geoheritage is an important natural resource that can represent a link between geosciences and the wider public, and all over the world initiatives have emerged to protect, value and enhance it. Therefore, geoheritage assessment is a fundamental step in choosing a correct land management strategy. The Liguria Region in Northern Italy is characterized by a wide geological and geomorphological variety, encompassing an important and valuable geoheritage. In Liguria, a regional law (L.R. 39/2009) protect and enhance geodiversity and geosites, establishing the Regional Inventory of Geosites. However, an approved official inventory is still lacking. In the present work a first reasoned inventory of 120 geosites is proposed for the Liguria Region, based on field surveys and literature review. A quantitative assessment of the value and the degradation risk was carried out. The value assessment takes into account the scientific value, the additional (aesthetic and cultural) value and the potential for use value; these three values are combined to obtain a total value (Q). Nine geosites obtain a Q value higher than 4: these geosites are among the best known of the Liguria region and are already exploited for tourism, such as the Palmaria and Tino islands, the Portovenere cliffs, the Gambatesa Mine, the Mt. Ramaceto sandstones, the Fascette Gorge, the S. Bernardino karst plateau, the Capo Mortola nummulitic limestones, the ophiolite outcrops of the Beigua Geopark and Framura. The degradation risk assessment takes into account both fragility and vulnerability of the geosites. The geosites selected and assessed in the present research will be implemented in the Regional Inventory of Geosites. Moreover, the results provides the necessary ground for interested parties to take actions for the implementation of effective regional geoconservation strategy or environmental management plan.
(Waste) Water quality sensor requirement and (too) high standards
Authors: Rübig Peter
Published: March 2021

Today in the water sector there are many methods for generating values in big databases. Everything should be connected in the cloud and everyone should access everything anytime. The data is changing very fast in every level and layer and should be controlled anytime. For better quality more methods in measuring data should be applied in parallel and so improve the quality, but this point is very complicated. You can not always compare different data measured by different methods, there are a lot of other enrivonmental factors  in most cases. Many systems in different countries exists with a lot of methods and values (eg. ph,chlorine,nitrate,germs,pathogens,viruses,micro/nano materials(plastic,metall,glass,wood,...),minerals(salt connections,...).
Continuous Improvement in the Performance and Operations of the Global Seismographic Network (GSN)
Authors: Hafner Katrin , Wilson Dave , Mellors Rob , Davis Pete
Published: March 2021

The decades long recordings of high-quality open data from the Global Seismographic Network have facilitated studies of earth structure and earthquake processes, as well as monitoring of earthquakes and explosions worldwide.  These data have also enabled a wide range of transformative, cross-disciplinary research that far exceeded the original expectations and design goals of the network, including studies of slow earthquakes, landslides, the Earth’s “hum”, glacial earthquakes, sea-state, climate change, and induced seismicity. 

The GSN continues to produce high quality waveform data, metadata, and multiple data quality metrics such as timing quality and noise levels.   This requires encouraging equipment vendors to develop modern instrumentation, upgrading the stations with new seismic sensors and infrastructure, implementing consistent and well documented calibrations, and monitoring of noise performance.    A Design Goals working group is convening to evaluate how well the GSN has met its original 1985 and 2002 goals, as well as how the network should evolve in order to be able to meet the requirements for enabling new research and monitoring capabilities.   

In collaboration with GEOFON and GEOSCOPE the GSN is also reviewing the current global distribution and performance of very broadband and broadband stations that comprise these three networks.  We are working to exchange our expertise and experience about new technologies and deployment techniques, and to identify regions where we could collaborate to make operations more efficient, where current efforts are overlapping or where we have similar needs for relocating stations. 