bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate change and cryosphere in high mountains: preliminary results of field monitoring at Capanna Margherita hut, Punta Gnifetti (Monte Rosa, Pennine Alps)
Authors: Giardino Marco , Montani Antonio , Tamburini Andrea , Calvetti Francesco , Borghi Alessandro , Alberto Walter , Villa Fabio , Martelli Davide , Salvalai Graziano , Perotti Luigi
Published: March 2020

In the last decades, climate change effects are spreading on cryosphere of mid latitude high mountains, affecting all environmental and territorial components. The Italian Alpine Club (CAI) is a privileged institution for observing climate change effects on cryosphere in high mountains, as well as for supporting scientists to proper assessment studies of related natural hazards, exposure, vulnerability effects, particularly those around alpine refuges and access routes. CAI has started a cooperative research with University of Torino (UniTO), Politecnico of Milano (PoliMI) and IMAGEO srl, focused in deglaciation, permafrost degradation and slope instabilities at the Punta Gnifetti peak (“Signal Kuppe, 4554 m a.s.l.), Monte Rosa (Pennine Alps, border between Italy and Switzerland). Here is the Margherita Hut, the highest refuge in Europe and a physical-meteorological observatory, as well as home to medical and scientific UniTO laboratories.

Activities started on May 2019 with a retrospective collection and interpretation of photos and archival news on the Punta Gnifetti environment. Multi-temporal geomorphological settings are compared to meteorological historical series for creating a morphoclimatic "timeline".

Instrumental monitoring and in situ field work began on August 2019, including: 1) determination of the ice thickness of the glacial cover by using georadar; 2) characterization of the geomechanical structure of the rock mass by means of terrestrial laser scanner; 3) establishment of a topographical reference point and georeferencing of all measuring points; 4) collection of litho-structural and geomorphological data for a reference geological model of the Punta Gnifetti; 5) photogrammetric helicopter flight for the 3D reconstruction of the site; 6) direct measurements of internal areas in order to obtain as-built building plans; 7) assessment of building services.

Preliminary results are presented here, together with directions for an effective data collection to be continued on 2020, including comparative analyses designated to: a) identify the relevant geomechanical features for rock mass stability; b) verify presence of ice inside fractures; c) reconstruct the ice-covered morphology of the Punta Gnifetti peak.
Mapping the U.S. Food-Energy-Water Nexus at the Mesocale: the FEW-View Visualization System
Authors: Rushforth Richard , Ruddell Benjamin
Published: March 2020

The FEWSION Project is an environmental data science project to build the first complete, empirical data-driven description of the U.S. food, energy, and water system (the FEW Nexus). The goal of the FEWSION Project is to produce FEW nexus data for researchers, decision-makers, and the public and to make this data accessible so that anyone in the U.S. can view the journey of their food, energy, and water. The FEWSION Project utilizes data fusion – the curated combination of multiple disparate datasets to create novel, synthetic datasets. There are numerous challenges to integrating food, energy, and water (FEW) system data. Chief among these challenges are data quality, availability, comprehensiveness, and accuracy. The first half of this presentation will discuss the FEWSION Project, the process of creating the FEWSION Database v. 1.0, and how we have made these data accessible. In the second half of this talk, there will be a demonstration of the FEW-View™ visualization system. FEW-View™ is an online educational tool built to visualize FEWSION Project data that is free and open to the public. Using FEW-View™, any U.S. resident and community leader can visualize their food, energy, and water supply chains.
Insights into downhole array spectra of hydraulic-fracturing induced seismicity in the Horn River Basin, British Columbia
Authors: Klinger Adam , Werner Max
Published: March 2020

Hydraulic fracturing underpins tight shale gas exploration but can induce seismicity. During stimulations, operators carefully monitor the spatio-temporal distribution and source parameters of seismic events to be able to respond to any changes and potentially reduce the chances of fault reactivation. Downhole arrays of geophones offer unique access to (sub) microseismic source parameters and can provide new insights into the processes that induce seismicity. For example, variations in stress drop might indicate changes in the seismic response to injection (e.g. pore pressure variations). However, borehole arrays of geophones and the high frequencies of small events also present new challenges for source characterization. Stress drop depends on the corner frequency, a parameter with great uncertainty that is sensitive to attenuation, especially for (sub-) microseismicity. Here, we explore the behavior of microseismic spectra measured along borehole arrays and the effect of attenuation on estimates of corner frequency. We examine a dataset of over 90,000 microseismic events recorded during hydraulic fracturing in the Horn River Basin, British Columbia. We only see clear phase arrivals for events Mw > -1 and restrict our initial analysis to a subsample of Mw> 0 events that vary in space and time.

Our first observation is that some stations in the borehole array show an unexpected increase in the displacement energy from the low frequency to the corner frequency in the P and SH phases as well as high-frequency energy spikes inconsistent with a smooth Brune source model. A shorter time window that only captures the direct arrival results in a flatter low frequency plateau and reduces the amplitude of the pulses but compromises the resolution. The spikes may be caused by high frequency coda energy. We also find that corner frequency estimates decrease with decreasing station depth along the array in both the P and SH phases, a likely result of high frequency attenuation along the downhole array. The findings suggest Brune corner frequencies of moment magnitudes < 0.5 may not be resolvable even with downhole arrays at close proximity. Our results will eventually contribute to a better characterization of microseismic source parameters measured in borehole arrays.

 
Lagrangian stochastic microphysics at unresolved scales in turbulent cloud simulations
Authors: Abade Gustavo , Waclawczyk Marta , Grabowski Wojciech W. , Pawlowska Hanna
Published: March 2020

Turbulent clouds are challenging to model and simulate due to uncertainties in microphysical processes occurring at unresolved subgrid scales (SGS). These processes include the transport of cloud particles, supersaturation fluctuations, turbulent mixing, and the resulting stochastic droplet activation and growth by condensation. In this work, we apply two different Lagrangian stochastic schemes to model SGS cloud microphysics. Collision and coalescence of droplets are not considered. Cloud droplets and unactivated cloud condensation nuclei (CCN) are described by Lagrangian particles (superdroplets). The first microphysical scheme directly models the supersaturation fluctuations experienced by each Lagrangian superdroplet as it moves with the air flow. Supersaturation fluctuations are driven by turbulent fluctuations of the droplet vertical velocity through the adiabatic cooling/warming effect. The second, more elaborate scheme uses both temperature and vapor mixing ratio as stochastic attributes attached to each superdroplet. It is based on the probability density function formalism that provides a consistent Eulerian-Lagrangian formulation of scalar transport in a turbulent flow. Both stochastic microphysical schemes are tested in a synthetic turbulent-like cloud flow that mimics a stratocumulus topped boundary layer. It is shown that SGS turbulence plays a key role in broadening the droplet-size distribution towards larger sizes. Also, the feedback on water vapor of stochastically activated droplets buffers the variations of the mean supersaturation driven the resolved transport. This extends the distance over which entrained CNN are activated inside the cloud layer and produces multimodal droplet-size distributions.
A 20-years dataset of the presence of Women in Geosciences within the Italian University
Authors: Nestola Fabrizio , Pamato Martha , Agnini Claudia , Salviulo Gabriella , Barchi Kim
Published: March 2020

Here we present data of the presence of women in the Italian university system in the field of geosciences in the last two decades. The official open sources we used to depict this scenario are those provided by MIUR (Italian Ministry of School, University and Research) and Alma Laurea. In the investigated interval some positive trends have been observed as for instance the increase in the number of female full professors from 9.9% to 18.5% and in female associate professors from 23.6% to 30.8%. However, these changes are still too slow, especially for full professors. A peculiarity of the Italian system is the recent creation of a new professional figure introduced by the new Italian Law no. 240/2010 that essentially is a tenure-track associate professor position (hereafter called RTD-b). Among RTD-bs the gender imbalance is an obvious concern seen that only 26% of these positions are occupied by female researchers and even more alarming if we considered the virtual no gender gap at Ph.D. level.

Looking in detail at the different fields of the geosciences, there are more positive situations as the case of Paleontology and Paleoecology where there is no the gap and Mineralogy where the gender imbalance in associate professors is irrelevant but a gender gap is still present at full professor level. A geographical analysis of our dataset has unraveled that, unexpectedly, the universities localized in the Northern richest industrial areas of Italy show a worse gender imbalance compared to Central and South Italy, though the situation has improved in the 20 years.

This study has thus highlighted that significant and positive changes has occurred in the last 20 years, but an important effort is still needed to further improve the situation in the Italian Universities. Possible actions to promote in order to achieve these results are related to the improvement of the welfare Italian system that could better reconcile family and work, stimulating a reorganization of the work system still currently set on the male model. A final positive thought is connected to the fact that in the Italian university system, there is no pay gap between males and females, something really relevant if compared with the salary gap (between 15% and 30%) present in other richer countries.
A top-down approach for quantifying methane and speciated VOC emissions from North Sea oil and gas facilities
Authors: Wilde Shona , Purvis Ruth , Lee James , Hopkins James , Lewis Alastair , Young Stuart , Burton Ralph , Colfescu Ioana , Pasternak Dominika , Mobbs Stephen , Bauguitte Stephane
Published: March 2020

The North Sea is home to around 200 offshore platforms that extract oil and natural gas from beneath the sea. Total offshore emissions (carbon dioxide (CO2), nitrogen oxides (NO + NO2 = NOx), nitrous oxide (N2O), sulphur dioxide (SO2), carbon monoxide (CO), methane (CH4) and total VOCs) from upstream oil and gas production in the UK increased by 7 % from 2016 to 2017. Therefore, the accurate measurement and analysis of leakage is critical for global emissions inventories and in terms of mitigating climate change. A recent study (Riddick et al., 2019) showed that on average methane leakage during normal operations is more than double what is reported to the UK National Emissions Inventory (NAEI) for each installation. Here we provide a top-down emissions estimation methodology from which emissions of CH4 and up to 30 individual volatile organic compounds (VOCs) can be estimated for point-source platforms. We apply a direct integration technique, and use VOC measurements obtained within downwind plumes as a tool for source identification. A total of 16 research flights were conducted as part of a joint project between the UK National Centre for Atmospheric Science (NCAS), BEIS, the UK Offshore Petroleum Regulator for Environment and Decommissioning (OPRED) and Ricardo Energy & Environment to characterise emissions from platforms in the North Sea. The hydrocarbon to ethane enhancement ratio within downwind plumes, measured under well-mixed boundary layer conditions, was used to scale a 1 Hz ethane measurement from the aircraft to other hydrocarbons collected using whole air samplers and measured using GC-FID. This allowed individual VOC emission rates to be calculated and compared to existing inventories. This work highlights how a top down technique can be used to quantify emissions and also provide insight into specific emission sources, in contrast to existing methods which often fail to achieve both simultaneously.
3D Structure of NEGIS shear margins from radar stratigraphy
Authors: Jansen Daniela , Franke Steven , Binder Tobias , Bons Paul , Dahl-Jensen Dorthe , Eisen Olaf , Helm Veit , Miller Heinrich , Neckel Niklas , Paden John , Steinhage Daniel , Weikusat Ilka
Published: March 2020

The North East Greenland Ice Stream (NEGIS) is delineated by well-defined shear margins, which are evident in the gradient of surface velocity field as well as in the surface topography, where they form troughs up to ten meters deep. In the upper part of the ice stream the margins appear not to be linked to bedrock topography. To understand this efficient system of mass transport towards the ocean it is essential to investigate the nature of the shear margins, as here very localized deformation decouples the inner ice stream from the slower flowing surrounding ice sheet. This process is influenced by several factors and feedback mechanisms, including the crystal fabric orientation, strain heating and localization of meltwater. In summary, the shear margins are area-wise a small part of the ice stream itself, but the processes leading to the localization of deformation are of similar importance for ice discharge as the processes enabling fast flow of the main trunk over the bed.

We present results from an airborne radar survey with the AWI Ultra-Wide Band Radar system, covering an area 150 km upstream and 100 km downstream of the deep drilling site on the ice stream (EGRIP). Over the survey area the ice stream accelerates from 12 m/a to 75 m/a. We focus on the signatures of the shear margins in the radar data. In the regions of localized shear, the internal reflections in the radargrams show disturbances in the form of steep undulations, or chevron folds, which are intensified with ongoing shear. As the ice stream has been covered with 36 flow-perpendicular radar sections we are able to show the evolution of these characteristic signatures over the survey area, and thus, as an analog, over time. 3D-representations of the folded stratigraphic layers reveal how new folds are formed when the ice stream widens and how older structures are preserved in the outer part of the main trunk, where they are no longer subject to shear. Furthermore, we link the change of the shape of the internal reflections in the shear zones to a strain rate field calculated from high resolution flow velocities derived by TerraSAR-X data.
SURFLAT: Measuring and modelling surface runoff in flat landscapes
Authors: Schaap Peter , de Louw Perry , van der Zee Sjoerd
Published: March 2020

Surface runoff is widely recognized as playing an important and unique role in contaminant
transport from agricultural fields to the river system. Its quantification however is still
underdeveloped, especially in flat areas. Because micro-topography (< 10 cm) likely is an
important controlling factor in such landscapes, accurate predictions of the occurrence and
quantity of surface runoff are limited by a lack of high-quality data and/or computational power.
This project will explore the applicability of both conceptual (fill-and-spill) and state-of-the-art
physically based models to estimate surface runoff at the field scale. Laser technology will provide
high resolution surface topography data and direct measurements of surface runoff will aid in
validating the hydrologic models. The goal of this research is to use the results of the field study to
develop an efficient and accurate upscaling scheme, centred around a generic parameterization of
micro-topographic variability. This could support decision and policy making and contribute to
increasing the water quality of river systems.
Analysis of methodological and physical bias on borehole temperature reconstructions from a pseudo-proxy approach.
Authors: Melo Aguilar Camilo , González Rouco Fidel , García Bustamante Elena , Steinert Norman , Navarro Jorge , Roldan Gómez Pedro , Jungclaus Johann
Published: March 2020

The analysis of subsurface temperature measurements from boreholes is a well established approach for reconstructing last millennium (LM) surface air temperature (SAT). It is based on the assumption that SAT variations are strongly coupled to ground surface temperature (GST) variations and transferred to the subsurface by thermal conduction. We have evaluated the long-term SAT-GST coupling over the LM using an ensemble of both full- and single-forcing simulations form the Community Earth System Model-Last Millennium Ensemble (CESM-LME). Such a premise is explored by investigating the evolution of the long-term SAT–GST relationship. The results indicate that SAT–GST coupling is strong at global and above multi-decadal timescales in CESM-LME. However, at local to regional scales this relationship experiences considerable long-term changes mostly after the end of the 19th century. Land use land cover (LULC) changes stand as the main driver for locally and regionally decoupling SAT and GST, due to the changes in the energy fluxes at the surface. Snow cover feedbacks due to the influence of GHG forcing are also important for corrupting the long-term SAT–GST coupling. These processes may represent a source of bias for SAT reconstructions from GST borehole profiles. In light of these findings, we subsequently assessed the potential effects on SAT reconstructions from the borehole method in pseudo-proxy experiments that make use of the same set of simulations from the CESM-LME. First, a heat-conduction forward model has been used to estimate subsurface temperature-anomaly profiles using simulated GST as boundary conditions. Subsequently, singular value decomposition inversion (SVD) has been applied to reconstruct LM GST variations from the simulated profiles. We implemented and ideal scenario in which it is assumed the existence of borehole logs at every model grid point. Further, this scenario considers that all boreholes are logged homogenously at the same time. In addition, we implemented a more realistic approach in which the real-world spatio-temporal distribution of the global borehole network is considered. Results show that the SVD inversion is able to retrieve the long-term GST variations over the LM when an appropriated coverture of borehole logs is available. However, due to the limited spatio-temporal distribution of the actual borehole network, there is a lost in the accuracy to retrieve the simulated GST 20th century trends, with the temporal logging of the BTPs as the main sampling issue. Furthermore, in the surrogate reality of the CESM-LME the SAT-GST decoupling, due to the influence of LULC and GHG forcings, leads to a slightly underestimation of SAT warming during the industrial period across the CESM-LME. The level of impact is, however, highly depended on the realization of internal variability.
Investigating the reaction pathway of crystalline orthocalciumphosphate formation via amorphous precursors in respect to different pH, Ca/P ratios and Mg presence
Authors: Hippler Dorothee , Schnedlitz Thomas , Purgstaller Bettina
Published: March 2020

The crystallization pathways of amorphous into crystalline orthocalciumphosphate phases is a widely discussed topic, with processes not yet entirely understood. Current research focuses on medical applications as well as natural sedimentary systems, for example bone-tissue-engineering, bio-mineralization and phosphogenesis, with inorganic precipitation experiments under controlled ambient conditions being the first step to improve our understanding of the fundamental formation processes. By mixing of stock solutions with CaCl2/MgCl2 and NaHPO4 we created a supersaturated solution in respect to CaPO4-phases and varied the pH by adding different amounts of NaOH. Continuous sampling was performed over the period of 24 hours, with sampling intervals after 1 min, 10 min, 60 min and 24 h. In order to record temporal changes in mineralogical and chemical composition, samples (solids and fluids) were investigated by XRD, FTIR, SEM and ICP-OES, respectively. Our experiments yield considerable differences concerning the time of amorphous calcium phosphate (ACP) transformation into hydroxyapatite (HAP), heavily depending on the pH, Ca/P ratio and Mg content of the stock solution. Main results show that a higher pH stabilizes the ACP over a period of the first 60 min, whereas at lower pH the transformation of ACP into the crystalline phase already starts at 10 min after mixing. Increasing the Ca/P ratio of the stock solution results in ACP being less stable and the transformation into HAP occurs earlier. In contrast, the presence of Mg seems to delay the formation of HAP via ACP. After 24 hours the experiments showed nano-crystalline HAP and most likely some other phases as octacalcium phosphate.
Stratification in the North Sea: response to different atmospheric forcing
Authors: Akpınar Anıl , Palmer Matthew
Published: March 2020

On-set of spring stratification is one of the physical factors that influence the productivity of the continental shelves. Atmospheric convective mixing determines the on-set of spring stratification. This is particularly important in seasonally stratified shelf seas, where stratification constrain nutrient injection to the water column. Higher productivity in stratified period relies on intermittent diapycnal mixing events. Thus, the on-set and intensity of stratification is important for the functioning of the shelf-sea ecosystem. In this study, we investigate on-set of stratification, and its relation with the atmospheric conditions as well as imprints of sub-mesoscale features. We use high resolution in-situ measurements from 10 glider deployments, spanning over 18 months in the central North Sea. Focusing on two consecutive winters, we present year to year variability in the timing and intensity of stratification. An early initiation of stratification is observed in 2018/2019, which is also intense compared to the previous year of 2017/2018. We find that reduced wind stress and net air-sea heat fluxes result in an early on-set of stratification in 2018/2019. In February 2019, intermittent increases in chlorophyll are observed, corresponding to a minimum in sea-to-air heat loss. Similarly, in 2019 an earlier spring bloom is observed. We investigate this period with NEMO model outputs at 7km resolution (AMM7) and show a similar response, emphasizing the influence of atmospheric variability on dynamics of the shelf-sea.   
Volcanology and Geothermal Resources: Participation of Landsvirkjun in the EUROVOLC project
Authors: Gudmundsson Asgrimur , Markusson Sigurdur , Sigmundsson Freysteinn , Hersir Gylfi Pall , Agustsson Kristjan
Published: March 2020

The Krafla power station was built by the Icelandic government 1975 and came under ownership of Landsvirkjun - The National Power Company of Iceland in 1985, and Bjarnarflag power station in Námafjall year later. These were the first steps for Landsvirkjun to generate electricity from geothermal resources in Iceland. Initially the company outsourced all geothermal research and monitoring, but systematically it trained people and hired geothermal experts and developed its own geothermal division. Theistareykir power plant, commissioned in 2017, was the first geothermal construction of Landsvirkjun from start to finish. Development and operation of geothermal fields at an active volcanic environment, such as in Krafla and Theistareykir, creates strong synergy with scientific research interest in volcanology and related branches of earth sciences and engineering. The strong infrastructure and wealth of data created by the energy company has catalysed important research interest and cooperation with scientist and has been a big part of Landsvirkjun´s operation from the beginning. Landsvirkjun makes data available from its databases from geothermal areas in Northeast Iceland within the EUROVOLC project. This is regarded a foundation of a successful industry and science community cooperation. The plan is to keep open source policy for researcher to access Landsvirkjun databases and metadata. Initially the emphasizes is on seismic and ground deformation data (GPS geodetic measurements). Landsvirkjun is running a seismic network consisting of 17 stations in NE-Iceland (http://lv.isor.is/ , in English and Icelandic), operated by Iceland GeoSurvey. Landsvirkjun has installed four continuously operating GPS stations in or near the geothermal areas in North Iceland: one in Theistareykir, two stations in Krafla and one in Bjarnarflag (operated by University of Iceland). In addition, GPS-measurement campaigns have been performed every year in the last decade covering the Krafla area (http://www.icelandsupersite.hi.is/gps/ts/NVZ.html). Borehole logs will be accessible, such as formation temperature and pressure. Also lithological logs (x,y,z) such as resistivity, neutron-neutron and gamma-ray. Interpretation reports of televiewer logs from selected wells will be available. Drill cuttings have been collected during drilling at over 70 deep wells at every two meters interval and lithology figures and cross sections will be available. All chemical data from high-temperature wells, groundwater wells, hot-springs and fumaroles will be available, either by request or through an on-line viewer access directly to Landsvirkjun chemical management system.
Towards a quantification of the water planetary boundary
Authors: Wang-Erlandsson Lan , Gleeson Tom , Jaramillo Fernando , Zipper Samuel C. , Gerten Dieter , Tobian Arne , Porkka Miina , Pranindita Agnes , van der Ent Ruud , Keys Patrick , Fetzer Ingo , Kummu Matti , Chrysafi Anna , Steffen Will , Savenije Hubert , Taniguchi Makoto , Gordon Line , Cornell Sarah , Staal Arie , Wada Yoshihide ,   et. al.
Published: March 2020

The planetary boundaries framework defines nine Earth system processes that together demarcate a safe operating space for humanity at the planetary scale. Freshwater - the bloodstream of the biosphere - is an obvious member of the planetary boundary framework.  Water fluxes and stores play a key role for the stability of the Earth’s climate and the world’s aquatic and terrestrial ecosystems. Recent work has proposed to represent the water planetary boundary through six sub-boundaries based on the five primary water stores, i.e., atmospheric water, soil moisture, surface water, groundwater, and frozen water. In order to make it usable on all spatial scales we examine bottom-up and top-down approaches for quantification of the water planetary boundary. For the bottom-up approaches, we explore possible spatially distributed variables defining each of the proposed sub-boundaries, as well as possible weighting factors and keystone regions that can be used for aggregation of the distributed water sub-boundaries to the global scale. For the top-down approaches, we re-examine the stability of key biomes and tipping elements in the Earth System that may be crucially influenced by water cycle modifications. To identify the most appropriate variables for representing the water planetary boundary, we evaluate the range of explored variables with regard to scientific evidence and scientific representation using a hierarchy-based evaluation framework. Finally, we compare the highest ranked top-down and bottom-up approaches in terms of the scientific outcome and implications for governance. In sum, this comprehensive and systematic identification and evaluation of variables, weighting factors, and baseline conditions provides a detailed basis for the future operational quantification of the water planetary boundary. 
R-Ladies Global, a worldwide organisation to promote gender diversity in the R community.
Authors: Bellini Saibene Yanina , Vitolo Claudia , LeDell Erin , Frick Hannah , Acion Laura
Published: March 2020

Having programming skills is becoming increasingly important for many geoscientists who wish to make their research as reproducible as it can possibly be. One of the most common languages of choice is the R language for statistical computing.

The R community, as other programming communities, suffers from underrepresentation of women and minority genders (e.g., trans men, non-binary, etc) in every role and area of participation, whether as leaders, package developers, conference speakers, conference participants, educators, or users.

As a diversity initiative, the mission of R-Ladies is to achieve proportionate representation by encouraging, inspiring, and empowering people of genders currently underrepresented in the R community. R-Ladies’ primary focus, therefore, is on supporting underrepresented-gender R enthusiasts to achieve their programming potential, by building a collaborative global network of R leaders, mentors, learners, and developers to facilitate individual and collective progress worldwide.

R-Ladies Global received funding for the first time in 2016, from the R Consortium (r-consortium.org, a Linux Foundation Project) and was quickly promoted to be a top-level project due to “its big commitment within the R community”.

The organization is articulated into ‘chapters’, groups hosting events in cities or remotely, the latter for the benefit of everyone, regardless of geographic location and personal circumstances. To date, R-Ladies fosters the development of 180 chapters organizing more than 2000 events in 50 countries around the world with more than 60,000 members and over 70,000 followers across the various Twitter accounts.

In this presentation, we will illustrate all the activities R-Ladies runs to support minority genders: from meetups (in-person meetings, where individuals can learn about new technologies and algorithms free of charge) to the R-Ladies directory (https://rladies.org/directory/), the abstract reviewers’ network (tinyurl.com/rladiesrevs), the Slack channels, the mentorship program, and much more.
Next-generation geophysical modelling
Authors: Nuterman Roman , Häfner Dion , Jochum Markus , Vinter Brian
Published: March 2020

So far, our pure Python, primitive equation ocean model Veros has been

about 50% slower than a corresponding Fortran implementation. But recent

benchmarks show that, thanks to a thriving scientific and machine

learning library ecosystem, tremendous speed-ups on GPU, and to a lesser

degree CPU, are within reach. On GPU, we find that the same model code

can reach a 2-5 times higher energy efficiency compared to a traditional

Fortran model.

We thus propose a new generation of geophysical models. One that

combines high-level abstractions and user friendliness on one hand, and

that leverages modern developments in high-performance computing on the

other hand.

We discuss what there is to gain from building models in high-level

programming languages, what we have achieved, and what the future holds

for us and the modelling community.
NASA new V3 Micro-Pulse Lidar Network Rain and Snow masking algorithm application: Aerosol wet deposition.
Authors: Lolli Simone , Vivone Gemine , Welton Ellsworth J. , Lewis Jasper R. , Sicard Micheal , Comeron Adolfo , Pappalardo Gelsomina
Published: March 2020

In this study we illustrate the development of a rain and snow masking algorithm applied to the National  Aeronautics and Space Administration (NASA) Micro-Pulse lidar network (MPLNET) observations. The algorithm, once operationally implemented, will deliver in Near Real Time (latency <1.5 hr) the rain and snow masking variables. The products will be publicly available on MPLNET website as part of the new Version 3 release. The methodology, based on image processing techniques, can detect only light to moderate rainfall and snowfall events (defined by intensity and duration) becasue of laser attenuation.  The main underlying technique consists in applying the morphological filters on the volume depolarization ratio composite image to identify  squared shapes under the cloud bases that corresponding to the precipitation. Results from the algorithm, besides filling a gap in precipitation and virga detection by radars, are of particular interest for the scientific community because will help to fully characterize the aerosol cycle, from emission to deposition, as precipitation is a crucial meteorological phenomena accelerating the atmospheric aerosol removal through the wet scavenging effect. As an example, in this study we prove, for the first time to our knowledge, how rain detection from ground-based lidar observations are effective in showing a strong negative correlation between the Aerosol Optical Depth (AOD) and precipitation.
Continuous (CFA) CH4 record of the Elbrus ice core, Caucasus (preliminary results)
Authors: Vladimirova Diana , Faïn Xavier , Ginot Patrick , Kutuzov Stanislav , Mikhalenko Vladimir
Published: March 2020

Methane (CH4) is the third most powerful greenhouse gas. However, its warming potential is two orders of magnitude higher than of carbon dioxide and its residence time in the atmosphere is only 9.1 ± 0.9 years. It makes CH4 a good indicator of rapid climate variations both under natural conditions and due to the anthropogenic influence.

The Elbrus ice core was drilled in 2009 on the Western Plato (43°20’53.9’’N, 42°25’36.0’’E) at elevation 5115 m a.s.l. It is 182 m long and is dated back to 280 ± 400 CE (Common Era). The CH4 mixing ratios were analyzed using a continuous flow analysis (CFA) system paired with optical-feedback cavity-enhanced absorption spectroscopy. The measurements campaign was organized at Institut des Géosciences de l'Environnement (IGE), Grenoble, France. This is a first high-resolution mid-latitude CH4 record. The record aims to better constrain the past evolution of mid-latitude methane sources.

Here we present preliminary results of the methane concentration measurements of the Elbrus ice core in high-resolution (CFA CH4 record). We observe in situ production (max level 2900 ppb) and a baseline. We inspect a potential origin of the multiple spikes in the high-resolution record. Supposedly, either an in-situ production in the dust-rich layers occurred or a gas dissolution in the melt layers took place. However, the possibility of in-situ production during continuous gas extraction has to be further studied. The identified melt layers can serve as an indicator of interrupted stable water isotopic signal and may be supportive in the regional temperature reconstructions based on the Elbrus ice core record. A cleaned off the spikes record is inspected for the natural variability of the CH4 baseline concentration related to the short-term climate and methane emissions variability.
3D Simulation of Fracture Propagation in Complex Reservoirs Rocks at Microscale
Authors: Nachev Victor , Kazak Andrey , Turuntaev Sergey
Published: March 2020

The hydraulic fracturing (HF) is one of the most commonly used methods for improving oil recovery. Improvement of HF efficiency requires the generation of an extensive network of secondary (non-main) fractures in the reservoir rock. This work aims to study the fracture propagation at the microscale for determining the optimal stress-strain states sustaining the most extensive network of secondary fractures. The solution accounts for rock microstructure at various scales, elastic strength parameters and elastic-plastic type of rock behavior during fracture propagation. The object of investigation is Berezov formation that features low permeability (< 1 mD) and pore dimensions down to tens of nanometers. Microstructural characterization employed computed tomography (CT) before and after geomechanical tests, quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) and energy dispersive spectroscopy. Geomechanical characterization included multi-stage compressive strength tests, Brazilian tensile strength testing. Data processing included the segmentation of micro-CT data, the 2D-QEMSCAN to 3D- micro-CT registration. For the digital rock model, the preparation we built the mesh, then populated the model with mechanical properties, defined the contact behavior between mineral grains and set boundary conditions. Using an advanced commercial mechanical simulator, we modeled fracture propagation at the microscale, obtained the simulations of fracture initiation and propagation in a 3D-homogeneous porous matrix, 2D stress-strain state of the heterogeneous material with nine minerals and fracture evolution through intergranular contacts. We found the appearance of a plasticity region in the heterogeneous matrix associated with fracture propagation. The research results allow improving the efficiency of HF operations at unconventional reservoirs and increasing production from isolated pore systems by creating an extensive secondary-fracture network.
Displacement, marginalization and changing economic structure: counting the intangible costs of riverbank erosion in Majuli island of India
Authors: Sahay Avijit
Published: March 2020

The paper focuses on the impact of riverbank erosion on the island of Majuli. Majuli is a large and populous river island in the India state of Assam. However, the island suffers from the erosional work of Rivers Brahmaputra in the south and Luhit in the north and this has led to the loss of land and the resultant displacement of population in 110 out of 243 villages of Majuli. The most significant impact of riverbank erosion has been on the livelihood pattern of the island, as erosion has affected both agriculture and fishing activities. However, the impact of erosion is not felt equally by the entire population of Majuli. Those who live near the banks of the river are disproportionately affected by erosion, while those living in the more central parts of the island have benefitted from it by using the changing economic structure of the island. Riverbank erosion has thus, had a profound impact on the society, economy and livelihood structure of the island and has created a more unequal society. The paper tries to count this intangible cost of riverbank erosion by analyzing the disparity in the economic impact of riverbank erosion from the perspective of political ecology with the help of survey and personal interviews carried out in Majuli.

Keywords: Majuli, Brahmaputra, Riverbank Erosion, Displacement, Economic Impact, Political Ecology
Plant phenology evaluation of CRESCENDO land surface models
Authors: Hemming Deborah , Peano Daniele , Materia Stefano , Park Taejin , Warlind David , Fan Yuanchao , Lee Hanna , Wiltshire Andy , Jones Chris D
Published: March 2020

A new generation of land surface models (LSMs) have been developed in the framework of the EU-funded CRESCENDO project aiming to improve understanding of the Earth system as part of the community CMIP6 effort. 
These new LSMs explicitly represent key processes in the carbon and nitrogen cycles, enabling more realistic vegetation-climate interactions to be simulated. For instance, vegetation phenology, the seasonality of vegetation, is explicitly represented in all these new LSMs. Intra- and inter-annual variations in vegetation phenology can substantially influence land-atmosphere exchanges of energy, moisture and carbon. Changes in phenological events also provide clear indicators of climate impacts on ecosystems. 
Results are presented on the evaluation of phenological variability from offline runs of this new generation of LSMs. In particular, the timing of growing season onset and offset at global scale, and the Leaf Area Index (LAI) peak timing are investigated using monthly mean outputs. Three satellite-derived LAI datasets are used as benchmark observations for this evaluation.
In general, LSMs exhibit high skill in reproducing the observed phenology cycle in the North hemisphere mid- and high-latitudes, while lower skill is obtained in the South hemisphere. All LSMs simulate an offset in the timing of the active vegetative season characterized by later onset and LAI peak. Offset timings are slightly better captured by the LSMs. For these reasons, further development of the representation of phenology is required in LSMs, especially in the South hemisphere, where more complex vegetation and reduced in-situ observations are available.
Induced Seismicity at the Preston New Road Shale Gas Site in Lancashire, UK – Site Characterisation and impact on the TLS
Authors: Delvoye Antoine , Edwards Ben
Published: March 2020

Recent examples have shown that fluid injection during hydraulic fracturing can result in felt, or even damaging, seismic activity. In the vicinity of the Preston New Road site (Lancashire, UK), almost 200 earthquakes of ML -0.8 to 2.9 have been recorded by the British Geological Survey (BGS) over the period from October 15th 2018 to September 2019. This corresponds to the period during which hydraulic fracturing (fracking) was carried out by the operator, Cuadrilla Resources. Throughout the operation, fracking had to be suspended temporarily five times as the ML 0.5 ‘red light’ of the UK regulatory Traffic Light System (TLS) was exceeded. Since 2017, the University of Liverpool has operated a seismic monitoring network comprising nine broadband Nanometrics Trillium 120 across the Blackpool-Preston region in order to determine the baseline seismicity and monitor induced events associated with the fracking operations atthe site. In addition to this network, both Cuadrilla and the BGS deployedseismometers-including borehole geophone strings-over the region making it oneof the best places in Europe for monitoring induced seismicity. The superficial geology of the region is dominated by thick sand, till and clay deposits, poten-tially leading to significant amplification of seismic waves. This amplification may lead to over-estimation of earthquake magnitude, and therefore increased likelihood of triggering mitigation measures associated with the TLS. In order to understand amplification effects near the PNR site, surface-wave measurements (both MASW and seismic Ambient Vibration Arrays, AVAs) have been used to derive dispersion curves and obtain VS profiles through an inversion process for station-site characterization. By using small local arrays (hundreds of meters wide) to regional arrays (tens of km wide), we reconstruct a velocity model down to the bedrock depth. This velocity model can then be used to compute a parshly non-ergodic ground motion and subsequently seismic hazard assessment. This approach allow us to account for site to site variability and result in reduced uncertainty in the hazard assessment. We find Vs30 in the range 200 – 300 m/s at the sites investigated, leading to significant amplification effects that may bias event magnitudes determined on a surface array.
Precession-paced climate oscillations in Messinian sulphate evaporites recorded by carbon stable isotopes of leaf wax derived n-alkanes
Authors: Stolwijk Dave , Natalicchio Marcello , Dela Pierre Francesco , Birgel Daniel , Peckmann Jörn
Published: March 2020

During the Messinian salinity crisis (MSC), the Mediterranean Sea was gradually isolated from the Atlantic Ocean due to tectonics, ultimately resulting in the deposition of enormous volumes of evaporites on the Mediterranean seafloor. In marginal Mediterranean sub-basins, the first phase of the MSC is represented by a cyclic succession of gypsum and shales (Primary Lower Gypsum unit; PLG), changing laterally into an alternation of shales, marls and carbonates towards the deeper parts of the basins. The current consensus is that the lithological cyclicity is the expression of precession-paced climate oscillations, with shales deposited during insolation maxima (precession minima) and gypsum deposited during insolation minima (precession maxima). However, this hypothesis has yet to be validated, because this assumption is primarily based on the continuation of sedimentary cyclicity from the open marine pre-MSC sediments into the Primary Lower Gypsum unit. To assess the possible role of orbitally-driven paleoclimate change on the deposition of the PLG unit, we have analysed molecular fossils (lipid biomarkers) preserved in shales and gypsum of the Pollenzo section (Piedmont basin, NW Italy).

Long-chain n-alkanes are reliable biomarkers that are used to track the input of terrestrial organic matter and allow to reconstruct paleovegetation. By using the distribution of higher plant-derived long chain n-alkanes and their compound specific carbon isotope signature (δ13C), we show that the sedimentary cyclicity in the PLG unit is indeed controlled by precession. Our high-resolution paleoclimatic proxy records cover approximately 300 Ka (6.003 Ma – 5.721 Ma) and comprise the onset of the MSC (5.971 Ma) and the first 12 cycles of the PLG unit. Cyclic fluctuation of δ13C values is observed, with higher δ13C values typifying long-chain n-alkanes extracted for gypsum, while lower values correspond to shales.

Our results, which represent the first paleoclimatic proxy data derived from Messinian gypsum, show that riverine flux of organic matter to the basin varied significantly during the first phase of the MSC. In agreement with a precessional control on paleoclimate, lower n-alkane abundance in gypsum reflects drier conditions, while higher n-alkane abundance in shales indicates more humid climate and increased input of terrestrial organic matter to the basin.
History and geography of land productivity to assess the challenges for food security
Authors: Tuninetti Marta , Ridolfi Luca , Laio Francesco
Published: March 2020

Increasing population and changing diets toward larger proportion of meat products have driven agricultural production increase over the past decades and will probably push it in the upcoming years. The analysis of the agricultural production increase is at the centre of the international debate since the 1800-century Malthusian prediction of exponentially growing population outstripping linearly increasing production.

In this study, we show how agriculture has changed over the past decades through the concept of a newly developed land productivity (LP) indicator, which measures the amount of calories, proteins, and fats produced per hectare of land and merges the variegate macronutrients spectrum of a 140-crops production basket. Land productivity indicator adds to the more widespread (crop specific) yield indicator the nutrient content of each product.

We find that the global LP has increased by 2.6-2.9% per year over 1961-2016 for calorie and protein, and 3.7% for fat. This confirms an important boost of the global productive regime whose growing rate has been able to overcome that of population. Humans can rely on larger amounts of calories (+1640 kcal/cap/day), proteins (+69 g/cap/day), and fats (+55 g/cap/day) supply. In this global picture, different macro-regions exhibit relevant heterogeneities. In particular, we found that Eastern Asian and Latin American countries could escape the Malthusian trap around the Nineties through both LP increase and ad hoc variation in the composition of their basket of products. However, this transition seems far to happen in Sub-Saharan Africa and South Asia, where the daily productive regime has remained stable since the Sixties, despite the variation of the basket composition.