bluuebunny/crossref_metadata_2025 huggingface dataset:
Project rAn:  Games to promote awareness of natural disasters in young students
Authors: Saraiva Jose , Doran Priscila , Doran Rosa
Published: March 2021

The Earth is an amazing planet. However, it is also an unpredictable and wild one – part of its many charms. Atmosphere, hydrosphere, geosphere are alive, and can unleash awesome forces on the whole planet, including the biosphere, of which we humans are part. It’s important to make young students aware of the fact that we all live in a planet that was not made specifically for humans, and that it is absolutely imperative that our species learns to respect it and its rhythms and cycles.

Human settlements are often located in pleasant areas, with little or no concern about their vulnerability to natural disasters. Authorities, local, regional and national, should make preparations to prevent and mitigate their occurrence, of course. But at least as important is the need to create awareness in the citizens, so they can face any disaster and react in a calm and orderly way. That task must begin at an early age. Other than learning to deal with natural disasters and avoiding panic, schoolkids can exert a powerful influence in the adult members of their families and alert them to the measures they should adopt to prepare for any future occurrence.

In project rAn, EU-funded, we aim to develop a serious game, adjusted to the age of the targets, that will teach them about four types of natural disaster (earthquakes, floods, fires and storms) and make them aware of how to prepare and react in case of one of them striking their city or village. The game will be easy to play, and given the small age of the players will not feature complex interactions. It will include contributions from teachers and groups of students from all Europe, that will be challenged to create small games on the subject, using the Scratch language.    
Spatio-temporal variations of PM2.5 and Respiratory Deposition Dose (RDD) before and during different COVID-19 lockdown phases at Delhi, India
Authors: Fatima Sadaf , Ahlawat Ajit , Mishra Sumit , Soni Vijay , Guleria Randeep
Published: March 2021

Present study explores pre-lockdown (1st January-24th March, 2020) and during lockdown (25th March-20th June, 2020) air quality changes in PM2.5 along with meteorological effects at megacity- Delhi (28.7041°N, 77.1025°E). Alipur (Rural), Okhla (Industrial) and Pusa Road (Traffic dominant area) experienced mean concentrations (S.D.) of PM2.5 as 87.56(±54.06), 124.45(±73.49) and 62.14(±58.64) µg/m3 before lockdown(BL; 1st January-24th March, 2020), while for Lockdown1(L1; 25th March-14th April, 2020), PM2.5 decreased drastically as 39.26(±16.31), 38.01(±15.16) and 31.03(±12.79) µg/m3 and gradually increased during Lockdown2(L2; 15th April-3rd May, 2020), Lockdown3(L3; : 4th May-17th May, 2020), Lockdown4(L4; 18th May-31st May, 2020), respectively. Percentage decrease in PM2.5 (-69.46%) correlated with outdoor activities of percentage decrease (-70 to -80%) in L1, from BL phase. Exposure assessment study showed, mean Respiratory Deposition Dose-RDD (S.D.) (µg/hr) for fine particles [Particle diameter (Dp) =0.5 µm] for walk and sit mode during BL, as 27.22(±13.53) and 9.90(±4.91) for Alipur, 30.55(±18.04) and 11.11(±6.56) for Okhla, and 28.67(±14.39) and 10.43(±5.23) for Pusa road, and decreased during L1 as 9.64(±4.00) and 3.50(±1.46) for Alipur, 9.33(±3.72) and 3.39(±1.35) for Okhla, and 7.62(±3.14) and 2.77(±1.14) for Pusa road, respectively. Delhiites were exposed to more fine RDD(walk/sit) before lockdown than during lockdown phases. People in sit mode found less exposed to fine RDD, in comparison to walk condition. The people living indoors were affected by outdoor RDD exposure with windows open condition, while exposed to different indoor pollution sources with windows closed condition during lockdown. Authors suggest avoid use of closed conditioned indoors and ACs; frequent opening of windows to lower the RDD and to minimize the COVID-19 virus transmission via particulates.

Keywords: PM2.5, RDD, COVID-19.
Towards the inclusion of sea-ice into a global tidal model
Authors: Vasulkar Amey , Verlaan Martin , Slobbe Cornelis
Published: March 2021

To study the effect of changing climate and declining sea ice on tides it is pertinent to include the effects of sea ice in a tidal model. Most of the hydrodynamic global tidal models either ignore the effect of sea ice on tides or approximately model it as an addition to the existing bottom frictional stress. Our focus is to extend an existing global tidal model (Global tide and storm surge model(GTSM), Verlaan et. al 2015) to include the effects of the Arctic sea ice on tides without coupling it to a sea ice model.

We propose to divide the sea ice cover into different regimes: landfast ice, free drift sea ice, and ice drifting under strong internal stresses, and treat each regime based on the physics between the respective regime and the tides.

It is seen that the free drift sea ice (almost) exactly follows the tides and has little to no effect on the tidal amplitudes and phases. In the case of landfast ice, we use the differences in landfast ice cover between the winter (maximum) and summer (zero) to check for the resulting differences in water levels and thus, comment on the performance of the model. Finally, the physics between the sea ice drifting under strong internal stresses and water is studied to model the effect of such ice on tides.
Transport and storage of anthropogenic contaminants in the Red River Delta, Vietnam 
Authors: Panizzo Virginia , Roberts Lucy , Do Nga , Taylor Sarah , Watts Michael , Hamilton Elliott , McGowan Suzanne , Trinh Duc , Leng Melanie , Salgado Jorge
Published: March 2021

Suspended particulate matter (SPM) in large rivers is the main source of material into delta river ecosystems and the world’s oceans, and is the primary carrier of heavy metals. Large rivers are therefore important sources of pollutant transport through the watershed and potentially alter natural riverine biogeochemical cycling. Asian mega-deltas are some of the most densely populated and urbanizing environments in the world, with pollution, erosion, and anthropogenic catchment modifications changing sediment fluxes and pollutant transport across their catchments. The River Delta (RRD), northern Vietnam, comprises 14,300 km2, making it the fourth largest delta in Southeast Asia. The area has a large population of >22 million and has seen a rapid increase in industry and agriculture with waste products from domestic activities, agriculture, and industry entering the river network often unregulated and untreated. To estimate the impacts of industrialisation in the RRD delta, we measured downriver suspended sediment and pollutant flux from 21 locations over a 17 month period from March 2018 to July 2019. Previous studies suggest sediment retention in the RRD, which is supported here in 2019 with ~30% of sediments retained in the delta. Increased precipitation in 2018, however, led to a ~40% increase in sediment delivery between the inlet and the outlets of the delta, most likely attributed to erosion. Anthropogenic contaminant loads between the inlet and outlets suggest the retention of heavy metals within the delta irrespective of the sediment flux (e.g. a reduction by ~4 and ~14% of SPM bound Cr between sites in 2018 and 2019). This may, in part, be due to spatial variations across the delta revealing ‘hotspots’ of pollution, with a progressive increase in the Cr concentration of SPM between Son Tay (a predominantly agricultural landscape) and Hanoi (a major industrialised urban area) suggesting domestic and industrial waste are major sources of heavy metal pollution. XRF data from upstream Hoa Binh reservoir sediment cores (collected 2017) will permit a comparison of background contaminant storage in the RRD catchment, to better quantify downstream impacts of anthropogenic activity as well as underpin the effects of impoundments on sediment export from the riverine system. Results highlight the role of deltas in ‘filtering’ contaminants to protect coastal areas, but the retention of high loads of pollutants also has potential consequences for the bioaccumulation of heavy metals through the food chain and could ultimately have severe consequences for aquatic and human health in these areas. 
Modelling the effect of Flood Retention Ponds in Arachthos River (Arta, Greece)  
Authors: Rontiris Georgios , Mitsopoulos George , Panagiotatou Elpida , Stamou Anastasios I.
Published: March 2021

Arachthos River is the largest river in Epirus and the 8th largest in Greece; it is 110 km long and its drainage area is 2209 km2. After emanating from Pindus mountains (near Metsovo), it enters into the Pournari Reservoir in Arta, passes through Arta and discharges into the Ambracian Gulf near Kommeno. Arachthos River prevents flooding of the city of Arta and supplies water to most of Epirus.

The design of flood protection works in Arachthos River is currently in progress; it is performed by a consortium of Greek Consulting Firms for the Ministry of Infrastructure and Transportation. In the present work, we examine the effect of Flood Retention Ponds on the inundation area and the subsequent flood risk for the city of Arta. The Flood Retention Ponds are constructed immediately downstream of the Pournari Reservoir and 5600 m upstream of the historic Bridge of Arta; their exact locations were identified after a preliminary study and field surveys. Firstly, we performed the design of the Flood Retention Ponds, based on international standards and specifications found in the international literature; then, we performed hydrodynamic calculations using the Hydrologic Engineering Center's-River Analysis System (HEC-RAS) 1D/2D with and without the Flood Retention Ponds. Thirdly, we compared the calculations and the corresponding inundation areas and derive conclusions on the effect of Flood Retention Ponds.

 

 
Multi-length TDR probes: future perspectives
Authors: Persico Raffaele , Farrugia Lourdes , Farhat Iman , Sammut Charles
Published: March 2021

In this contribution we will propose the use of multi-length TDR probes for measurements of the dielectric and possibly magnetic characteristics of a material under test (MUT) as a function of frequency. The multi-length strategy, consisting in making use of a TDR probe with adjustable length of the conductors, can allow the meaningful increase of information achievable about the MUT at each test frequency. We are still at an early stage about these possibilities, and many questions are still open at this time. However, some of our previous studies [1-3] show that the method is promising and can permit the acquisition of some information not intrinsically available from a traditional TDR probe, especially if the MUT shows a dispersive behaviour and possibly magnetic properties. In this contribution, we will discuss the recent work related in particular to geophysical applications.

Acknowledgements

This work in progress is being carried out within the European Cost Action CA17115 Mywave.

References

[1] R. Persico, M. Pieraccini, Measurement of dielectric and magnetic properties of Materials by means of a TDR probe, Near Surface Geophysics, vol. 16, n.2, pp.1-9, DOI:10.3997/1873-0604.2017046, 2018.

[2] R. Persico, I. Farhat, L. Farrugia, S. d’Amico, C. Sammut, An innovative use of TDR probes: First numerical validations with a coaxial cable, Journal of Environmental & Engineering Geophysics, doi.org/10.2113/JEEG23.4.437, 23 (4): 437-442, 2018.

[3] I. Farhat, L. Farrugia, R. Persico, S. D’Amico, and C. Sammut, Preliminary Experimental Measurements of the Dielectric and Magnetic Properties of a Material with a Coaxial TDR Probe in Reﬂection Mode, Progress In Electromagnetics Research M, Vol. 91, 111–121, 2020.
Global temperature and hydroclimate in warmer climates of the past and future: the Last Interglacial versus greenhouse scenarios
Authors: Scussolini Paolo , Bakker Pepijn , De Luca Paolo , Coumou Dim , Bosmans Joyce , Lohmann Gerrit , Thomas Zoë , Turney Chris , Menviel Laurie , Obase Takashi , Abe-Ouchi Ayako , Braconnot Pascale , Otto-Bliesner Bette , Yin Qiuzhen , Prange Matthias , Tzedakis Chronis , Capron Emilie , Renssen Hans , Ward Philip , Aerts Jeroen
Published: March 2021

Past climates contain precious information about the workings of the climate system, and about what can be expected in a changed climate. The Last Interglacial (LIG; ca. 125,000 years ago) is the most recent period of climate warmer than modern, at least in the Northern Hemisphere. Because of this, it has been often proposed that the LIG holds a partial analogy with a future warmer climate forced by enhanced greenhouse effect. Still, such analogy has never been examined in a quantitative manner. Here we address the question: for which scenario, time horizon, regions and season is the climate of the LIG a useful analogue of the future? We use the results of 13 climate models that performed the standard experiments of PMIP4 and CMIP6, and present a comparison of hemispheric temperature and precipitation between the LIG and SSP scenarios of the future. We also two independent assessments of models performance, by comparing their temperature and precipitation to climate reanalysis of the last decades and to proxies of the LIG. Insights gained from this comparison can inform studies in disciplines beyond climate studies, such as hydrology and ecology.
New and revised magnetostratigraphic age constraints on the Akchagylian (late Pliocene) five-fold expansion of the Caspian Sea.
Authors: Lazarev Sergei , Kuiper Klaudia , Oms Oriol , Bukhsianidze Maia , Vasilyan Davit , Jorissen Elisabeth , Krijgsman Wout
Published: March 2021

The late Pliocene Akchagylian transgression in the Caspian Basin led to a five-fold increase of the Caspian Sea surface water, extending the basin to the vast areas of Central Asia, Caucasian foreland (Kura Basin) and the Russian Plate. It also changed the regional climatic conditions by making the Pliocene glaciation milder. Later, establishment of hydrological connection between the Caspian Sea and the global ocean known as the “Akchagylian flooding” enabled active fauna migrations transforming the paleoecology of the region. Despite a relatively well constrained palaeoenvironmental history, the Akchagylian still lacks a univocal age model and two major age constraints exist - the “long” (3.6-1.8 Ma) and the “short” Akchagylian (2.7-2.1 Ma). In this study, we resolve the age contradictions by magnetostratigraphic and 40Ar/39Ar dating of several sections in the Kura Basin. With our new data, we further revise magnetostratigraphy and 40Ar/39Ar constraints in 25 sections across the Kura Basin and Turkmenistan. We propose a new unified age model for the Akchagylian Stage: 1. Akchagylian transgression at 2.95±0.02 Ma; 2. Caspian-Arctic connection (2.75–2.45 Ma); 3. “Desalinated” Akchagylian between 2.45-2.13 Ma; 4. Akchagylian-Apsheronian boundary at 2.13 Ma correlated to the Reunion subchron (C2r.1n). Our data shows, that magnetostratigraphy requires a careful assessment of sedimentation rates and support from other proxies such as sedimentology, biostratigraphy and radioisotopic dating. The new ages constrain a much shorter (2.95–2.1 Ma) Akchagylian than in previously mentioned regional geological time scales (3.6–1.8 Ma) and strongly appeal to reconsider the ages of numerous archaeological and mammalian sites in the south Caspian region.
Communicating geosciences in the digital age
Authors: Pease Roland
Published: March 2021

It was in mid-March 1987 that I first took up my desk at Nature's bookish offices in Little Essex St, not quite 20 years after Jason Morgan's epochal and poorly understood AGU talk on the mechanisms of plate tectonics. Within days I was editing articles on the topic, which seemed as ancient and established as the mountains themselves. So, a further 30 years on, it's unnerving to recognise how young, yet successful the paradigm was. Climate science was similarly finding its feet at the time. These global forces that shape the planet, shape people's lives too, and often in an instant. This is what makes accurate and timely reporting of earth sciences compelling. What's also been transformed is communication. Then, it was by post, or via the new "fax" machine that arrived shortly after me. How that has changed! In this talk I will reflect on the the key role digital media, social media in particular, play in contemporary reporting on geosciences and the environment.
Application of Sentinel-2A/B satellites to retrieve turbidity in the Guadalquivir estuary (Southern Spain)
Authors: Chowdhury Masuma , Vilas César , VanBergeijk Stef , Navarro Gabriel , Laiz Irene , Caballero Isabel
Published: March 2021

Application of Sentinel-2A/B satellites to retrieve turbidity in the Guadalquivir estuary (Southern Spain)

Due to climate change, contamination, and diverse anthropogenic effects, water quality monitoring is intensifying its importance nowadays. Remote sensing techniques are becoming an important tool, in parallel with fieldwork, for supporting the cost-effective accomplishment of water quality mapping and management. In the recent years, Sentinel-2A/B twin satellites of the European Commission Earth Observation Copernicus programme emerged as a promising way to monitor complex coastal waters with higher spatial, spectral and temporal resolution. However, atmospheric and sunglint correction for the Sentinel-2 data over the coastal and inland waters is one of the major challenges in terms of accurate water quality retrieval. This study aimed at evaluating the ACOLITE atmospheric correction processor in order to develop a regional turbidity model for the Guadalquivir estuary (southern Spain) and its adjacent coastal region using Sentinel-2 imagery at a 10 m spatial resolution. Two settings for the atmospheric correction algorithm within the ACOLITE software were applied: the standard dark spectrum fitting (DSF) and the DSF with an additional option for sunglint correction. Turbidity field data were collected for calibration/validation purposes from the monthly Guadalquivir Estuary-LTER programme by Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA) using a YSI-EXO2 multiparametric sonde for the period 2017-2020 at 2 fixed stations (Bonanza and Tarfia) sampling 4 different water masses along the estuary salinity gradient. Several regional models were evaluated using the red band (665 nm) and the red-edge bands (i.e. 704, 740, 783 nm) of the Sentinel-2 satellites. The results revealed that DSF with glint correction performs better than without glint correction, especially for this region where sunglint is a major concern during summer, affecting most of the satellite scenes. This study demonstrates the invaluable potential of the Sentinel-2A/B mission to monitor complex coastal waters even though they were not designed for aquatic remote sensing applications. This improved knowledge will be a helpful guideline and tool for the coastal managers, policy-makers, stakeholders and the scientific community for ensuring sustainable ecosystem-based coastal resource management under a global climate change scenario.
Exploring the Tropospheric Response to Stratospheric Variability Using Lagged Quantile Regression
Authors: Finke Kathrin , Hannachi Abdel
Published: March 2021

Stratospheric variability has become increasingly popular due to its potential impact on the tropospheric circulation. Extreme states of the stratospheric polar vortex have been associated with reoccurring tropospheric weather patterns more than 2-3 weeks after the initial stratospheric signal. Standard linear regression methods used to assess the statistical stratosphere-troposphere connection estimate the distribution's mean effect of a stratospheric variable as a predictor on a tropospheric response variable. However,  supplementary information of the impact of extreme stratospheric behavior is hidden in the tails of the distribution, revealing a different behavior than the mean. Therefore, we use quantile regression, a method that enables us to model the complete conditional distribution of the response variable. This presentation explores various quantiles of the conditional distribution to investigate the impact of stratospheric variability on the tropospheric circulation using the ERA5 reanalysis dataset. Comparison between (lagged) linear and (lagged) quantile regression reveals significant differences making the latter method a neat tool that offers valuable information about the statistical connection between the stratosphere and the troposphere.
Understanding the impact of bathymetric changes in the German Bight on coastal dynamics: One step towards realistic morphodynamic modeling
Authors: Jacob Benjamin , Stanev Emil
Published: March 2021

The  hydrodynamic response to morphodynamic variability in the coastal German Bight was analyzed  via numerical experiments using time-referenced bathymetric data for the period 1982-2012. To this aim, time slice experiments were conducted for each year with the Semi-implicit Cross-scale Hydroscience Integrated System  model (SCHISM). This is an unstructured grid model, which allows to resolve small-scale bathymetric features in the coastal zone, which are also resolved in the time-referenced bathymetric data with their fine horizontal resolution of 50\,m. The analysis of bathymetric data reveals continuous evolution of small-scale bathymetric features and, e.g., the migration of tidal channels and rather complex change of the depths of tidal flats in different periods. The almost linear relationship between the cross-sectional inlet areas and the tidal prisms of the intertidal basins in the East Frisian Wadden Sea demonstrates that these bathymetric data describe a consistent morphodynamic evolutionary trend. The results of numerical experiments are streamlined to explain the changes of hydrodynamics from 1982 to 2012. Although these changes were located mostly in a relatively small part of the model area, they resulted in substantial changes (exceeding 5\,cm) in the amplitudes of M2 tides.  The  hydrodynamic response to bathymetric changes exceeded largely the response to sea-level change. The tidal asymmetry appeared very sensitive to bathymetric changes, particularly between the southern tip of Sylt island and the Eider Estuary along the eastern coast. The peak current asymmetry weakened from 1982 to 1995 and even reversed in some of the tidal basins to become flood-dominant. This would suggest that the flushing trend in the 1980s was reduced or inverted in the second half of the period of bathymetric observations. Salinity also appeared sensitive to bathymetric changes; the deviations in the individual years reached ~2 psu in the tidal channels and tidal flats. One practical conclusion from the present numerical simulations is that wherever possible, the numerical modeling of near-coastal zones must employ time-referenced bathymetry.
Gas-sensors-equipped drone measurements of volcanic plume gas composition and flux at Pisciarelli, Campi Flegrei, Italy
Authors: Tamburello Giancarlo , Marotta Enrica , Belviso Pasquale , Avvisati Gala , Ricci Tullio , Rouwet Dmitri , Avino Rosario , Caliro Stefano
Published: March 2021

The fumarolic field of Pisciarelli is the most active vent of the Campi Flegrei caldera, a volcano in the metropolitan area of Naples (Italy) in a current state of unrest. Recent studies have identified a clear escalation of degassing activity at Pisciarelli since 2012, raising concern on a possible acceleration of the unrest. The absence of sulfur dioxide prevents UV spectroscopy from determining the volcanic gas flux, and researchers have tried alternative techniques for measuring CO2 and H2S fluxes. Here we report observations of CO2, H2S, and H2O concentrations in the plume of Pisciarelli derived on December 2019 and October 2020 with a hexacopter drone equipped with miniaturized diffusive gas sensors. The drone flew at a constant altitude (~50 m above ground level), transecting the gas plume multiple times. This technique allowed us to calculate the CO2, H2S, and H2O gas fluxes by combining the georeferenced gas concentrations with the plume vertical rising speed derived from thermal and visible camera footages. Similar to previous gas composition and flux measurements, our results suggest that gas-sensors-equipped drones are a cost-effective technique for monitoring gas fluxes on active volcanoes, where UV spectroscopy cannot be used, and that can be made from safe distances.
Linking circular economy and environmental rehabilitation in the designed Technosols for highmountain pastures implementation
Authors: Santos Erika , Arán Diego
Published: March 2021

Although at different features and intensities, both abandoned and active mines as well as other industrial areas associated to mining activity, have several environmental problems associated to extreme physicochemical characteristics of their materials, wastes and/or leachates. The conventional closure systems do not contribute to the improvement of the chemical characteristics of some contaminated materials and its leachates. Moreover, superficial layer of soil applied in the conventional closure systems have very high cost of implementation and, especially, maintenance since this is periodically fertilized with organic amendments and re-sown.  

Nowadays, the strategies and technologies for tailings and deposits closure should be based on sustainability and the circular economy. In this context, an effective solution is the use of Technosols derived of wastes and designed specifically for each contaminated/degraded materials in order to remediate, at integrated level, the different components of the ecosystem and reconverting non-productive and degraded areas. The development and in situ application of designed Technosols to growth of highmountain pastures was carried out, firstly, under controlled conditions to evaluate the physic-chemical quality of the designed Technosols and then under field conditions. After superficial application of the Technosol on tailing deposit containing sulfide-rich wastes, plant cover was monitored for one year. The efficiency of Technosol in the improvement of chemical characteristics of mine wastes located under it was evaluated. Technosol was also evaluated in order to confirm the maintenance of its properties and characteristics.

Even in the highmountain conditions, a rapid germination, development and coverage of the surface by herbaceous species was obtained. In three months, there was less than 35% of bare soil. The percentage of bare soil decreased over time and in six months plant cover reached more than 85 % and a height of 65 cm. The productivity of the pasture was between 3 and 9 kg/m2. Plants did not show visible signs of phytotoxicity or nutritional deficiency and elements concentrations in shoots were in normal range, considering plants species in general.  Pasture does not seem to represent an environmental risk for domestic animals that exist in the areas adjacent. The chemical characteristics and andic and eutrophic properties of the Tecnosol were maintained. The Tecnosol stimulated the functionality of the microorganisms-soil-plant system, as well as the alteration of chemical characteristic and microbiological communities of the deposit.

Acknowledgment: This research was supported by Portuguese funds, through Fundação para a Ciência e Tecnologia, within the scope of the project UID/AGR/04129/2020.
An unsuspected biomineralization process in the green algae class Chlorodendrophyceae 
Authors: Segovia Campos Inés , Martignier Agathe , Filella Montserrat , Ariztegui Daniel
Published: March 2021

Chlorodendrophyceae are a class of unicellular green algae widespread in the aquatic environment (seawater, brackish water, and freshwater) that have recently been discovered to form intracellular carbonates. These mineral inclusions, called micropearls, are mainly composed of hydrated amorphous calcium carbonates (ACC) in which strontium can also accumulate at high concentrations. Under natural and culture conditions, the Sr/Ca ratio of micropearls can be 200 times higher than in their environment, suggesting that Chlorodendrophyceae species may be considered as potential candidates for new bioremediation methods regarding radioactive 90Sr water contamination. Because very little is known about this phenomenon, ongoing experiments with laboratory cultures are providing essential information about the cellular mechanisms involved in this newly discovered biomineralization process and its impact on the geochemical cycles of Ca and Sr.
Evaporite dynamics and their effects on global climate and oxygen
Authors: Shields Graham , Mills Benjamin
Published: March 2021

Evaporite weathering and deposition are seldom in balance even on million-year time-scales with grand depositional events superimposed against a background of more slowly varying weathering. Despite such imbalance, biogeochemical models generally assume that evaporite weathering and deposition rates are equal on all time scales. Changes in evaporite dynamics through time will likely impact oxidant budgets through the sulfur cycle and we have shown this to have been especially significant during Proterozoic times. Recently, we proposed that imbalances between evaporite weathering and deposition can also affect climate through the process of carbonate sedimentation. Calcium sulfate weathering supplies calcium ions to the ocean unaccompanied by carbonate alkalinity, so that increased carbonate precipitation strengthens greenhouse forcing through transfer of carbon dioxide to the atmosphere. Conversely, calcium sulfate deposition weakens greenhouse forcing, while the high depositional rates of evaporite giants may overwhelm the silicate weathering feedback, causing several degrees of planetary cooling. Non-steady-state evaporite dynamics and related feedbacks have hitherto been overlooked as drivers of long-term carbon cycle change. In this talk, we illustrate the importance of evaporite deposition, in particular, by showing how a series of massive depositional events contributed to global cooling during the mid–late Miocene. Further studies are required to quantify gypsum deposition over time and its possible effects on deoxygenation of the surface environment, especially at times of mass extinction, as well as on climate.
Characterisation and comparison of slow coronal hole wind intervals at 0.13au
Authors: Woolley Thomas , Matteini Lorenzo , Horbury Timothy S , Laker Ronan , Woodham Lloyd D , Bale Stuart D , Stawarz Julia E , Berčič Laura , McManus Michael D , Badman Samuel T
Published: March 2021

The slow solar wind is thought to consist of a component originating close to the Heliospheric Current Sheet (HCS) in the streamer belt and a component from over-expanded coronal hole boundaries. In order to understand the roles of these contributions with different origin, it is important to separate and characterise them. By exploiting the fact that Parker Solar Probe’s fourth and fifth orbits were the same and the solar conditions were similar, we identify intervals of slow polar coronal hole wind sampled at approximately the same heliocentric distance and latitude. Here, solar wind properties are compared, highlighting typical conditions of the slow coronal hole wind closer to the Sun than ever before. We explore different properties of the plasma, including composition, spectra and microphysics, and discuss possible origins for the features that are observed.
Projected changes in pyroconvective conditions in the Iberian Peninsula at the end of the 21st century
Authors: Senande-Rivera Martín , Miguez-Macho Gonzalo
Published: March 2021

Extreme wildfire events associated with strong pyroconvection have gained the attention of the scientific community and the society in recent years. Strong convection in the fire plume can influence fire behaviour, as downdrafts can cause abrupt variations in surface wind direction and speed that can result in bursts of unexpected fire propagation. Climate change is expected to increase the length of the fire season and the extreme wildfire potential, so the risk of pyroconvection occurence might be also altered. Here, we analyse atmospheric stability and near-surface fire weather conditions in the Iberian Peninsula at the end of the 21st century to assess the projected changes in pyroconvective risk during favourable weather conditions for wildfire spread.  
Slowly migrating tectonic microearthquake swarms in the Icelandic Rift Zone: driven by pore-pressure or aseismic slip transients?
Authors: Winder Tom , White Robert S
Published: March 2021

Intense swarms of microearthquakes have been detected in the rift zone of Central Iceland since the 1970s, but the cause of their clear swarm-like nature remains enigmatic. We use the QuakeMigrate earthquake detection and location software1 to produce a highly complete catalogue of microseismicity from 2007-2020, using data from a dense local seismic network. Automatic hypocentre locations have been refined using waveform cross-correlation and double-difference relocation, and tightly constrained focal mechanisms have been obtained by manual analysis of a subset of events.

The resulting high-resolution earthquake catalogue reveals a network of conjugate strike-slip faults, oriented to accommodate plate-boundary extension. Sharply defined fault planes imaged by the microearthquake hypocentres range from 1-10 km in length, and are found between 1 and 8 km b.s.l., with their orientations closely matching the fault plane geometry inferred from the fault plane solutions. Seismicity within individual swarms displays a systematic migration of hypocentres at velocities of ~ 1 km/day. In the majority of swarms we also observe clusters of identical repeating events, providing evidence for re-loading of brittle asperities.

For a selection of swarms our high resolution seismic observations are complemented by GPS and InSAR measurements, allowing us to place constraints on the amount of fault slip. Comparing this, and the area of the fault plane activated in the swarm, to the seismic moment release reveals a significant contribution of aseismic slip, or very low effective stress drop. Analysis of swarms within this fault network triggered by the 2014 Bárðarbunga-Holuhraun dike intrusion provides further constraint on the amplitude of the stress cycle.

We combine our observations with comparisons to numerical & laboratory modelling studies, observed swarm scaling properties and knowledge of the geological and permeability structure of the Icelandic crust to determine the nature of the transient forcing driving these exceptionally well-recorded tectonic earthquake swarms.

 

1: https://github.com/QuakeMigrate/QuakeMigrate Tom Winder, Conor Bacon, Jonathan D. Smith, Thomas S. Hudson, Julian Drew, & Robert S. White. (2021, January 15). QuakeMigrate v1.0.0 (Version v1.0.0). Zenodo. http://doi.org/10.5281/zenodo.4442749
Continuous observation of canopy water content changes with GPS sensors
Authors: Humphrey Vincent , Dorsey Brian L. , Frankenberg Christian
Published: March 2021

Canopy water content is a direct indicator of vegetation water use and hydraulic stress, reflecting how ecosystems respond and adapt to droughts and heatwaves. It represents an interesting target for Earth system models which attempt to predict the response and resilience of the vegetation in the face of changing climatic conditions. So far, in-situ estimates of vegetation water content often rely on infrequent and time-consuming samplings of leaf water content, which are not necessarily representative of the canopy scale. On the other hand, several satellite techniques have demonstrated a promising potential for monitoring vegetation optical depth and water content, but these large-scale measurements are still difficult to reference against sparse in-situ level observations.

Here, we present an experimental technique based on Global Navigation Satellite Systems (GNSS) to bridge this persisting scale gap. Because GNSS microwave signals are obstructed and scattered by vegetation and liquid water, placing a GNSS sensor in a forest and measuring changes in signal quality can provide continuous information on canopy water content and forest structure. We demonstrate that variations in GNSS signal attenuation reflect the distribution of biomass density and liquid water in the canopy, consistent with ancillary relative leaf water content measurements, and can be monitored continuously. Of particular interest, this technique can resolve diurnal variations in canopy water content at sub-hourly time steps. The few rainfall events captured during the 8-months observational record also suggest that canopy water interception can be monitored at 5 minutes intervals. We discuss future strategies and requirements for deploying such off-the-shelf passive bistatic radar systems at existing FluxNet sites.
Testing UNFC as a harmonized supporting tool for resource management in Europe
Authors: Aasly Kari , Eil Pasi , Schjøth Frands , Flindt-Jørgensen Lisbeth
Published: March 2021

With the global increase in raw material demand comes the need for harmonized supporting tools for sustainable resource management in Europe. Europe needs to assess their resource potential, but the European countries do not have a common tool to aggregate information for continent-wide resource inventories. The United Nations Framework Classification for Resources (UNFC) is a system that may be used for this purpose.

One of the specific tasks in the MINTELL4EU project under the GeoERA programme is to test if the European geological surveys will be able to use UNFC as a tool to evaluate a country’s known and potential resources across variable levels of knowledge. The project will also show, if the application of UNFC can provide better harmonization of mineral resource data nationally and across Europe.

The work on UNFC in MINTELL4EU is based on case studies to gain experience. Based on the knowledge and lessons learned from the case studies, guidelines and recommendations for further work will be given. Preliminary results show that there is a need for a more harmonized system and that stricter guidelines are required. On top of this, there are different levels of experience in UNFC among the European geological surveys, and the approach and methods on UNFC varies between the countries.
Dynamical and Thermodynamic Changes in the Historical Response of Atlantic Sector Rainfall to Anthropogenic Emissions in the IPSL-5A Model.
Authors: Wenhaji Ndomeni Claudine , Giannini Alessandra
Published: March 2021

CMIP5 models, including IPSL-5A, developed at the Institut Pierre Simon Laplace, largely reproduce the observed post-World War II decline in Sahel precipitation. We use all- and single-forcing historical simulations performed with IPSL-5A to better understand the impact of emissions of aerosols and greenhouse gases in Sahel drought. Specifically, we analyze the moisture budget to assess the two main processes, namely stabilization and moisture supply, that are hypothesized to shape moisture convergence and precipitation in the Atlantic sector.

1) The net change has the sign of the expected thermodynamic change: an increase in precipitation in GHG-induced warming, and a decrease in aerosol-induced cooling. Thermodynamic change is opposed by dynamical change.

The rainfall change in GHG-induced warming, in the Sahel as well as across all other regions of climatological precipitation, including the Atlantic Intertropical Convergence Zone (ITCZ), is positive and largely dominated by the change in the thermodynamic term associated with convergence, meaning that the change is consistent with an increase in moisture that assumes no change in the atmospheric circulation: as the ocean warms, it supplies more moisture to the monsoon.

This wetting thermodynamic term associated with convergence is opposed by drying associated with the corresponding dynamical term, which is especially strong at the margins, and signifies a weakened mass flux, or slow-down of the overturning circulation. This negative change in mass convergence is symptomatic of stabilization in a warmer world.

The effect of sulfate aerosol-induced cooling is equal and opposite to that of GHG-induced warming.

2) The ITCZ response is complicated by the dynamical ocean feedback associated with changes in the meridional gradient in sea surface temperature. GHG-induced warming leads not only to an increase in precipitation, but also to a poleward shift of the ITCZ. This poleward shift is accompanied by (south) westerly wind anomalies, which drive an off-equatorial cooling Ekman flow equatorward of the ITCZ. These same westerly anomalies induce a weakening of equatorial upwelling, and warming of the eastern equatorial Atlantic cold tongue.

Here, too, the effect of sulfate aerosol-induced cooling is equal and opposite to that of GHG-induced warming. An equatorward shift of the ITCZ is accompanied by (north) easterly wind anomalies, which drive off-equatorial warming, and equatorial cooling.
Beyond Cloud: A Fused Optic and SAR Based Solution to Monitor Crop Health
Authors: Pagán Brianna , Ajayi Adekunle , Krouma Mamadou , Budideti Jyotsna , Tafsi Omar
Published: March 2021

The value of satellite imagery to monitor crop health in near-real time continues to exponentially grow as more missions are launched making data available at higher spatial and temporal scales. Yet cloud cover remains an issue for utilizing vegetation indexes (VIs) solely based on optic imagery, especially in certain regions and climates. Previous research has proven the ability to reconstruct VIs like the Normalized Difference Vegetation Index (NDVI) and Leaf Area Index (LAI) by leveraging synthetic aperture radar (SAR) datasets, which are not inhibited by cloud cover. Publicly available data from SAR missions like Sentinel-1 at relatively decent spatial resolutions present the opportunity for more affordable options for agriculture users to integrate satellite imagery in their day to day operations. Previous research has successfully reconstructed optic VIs (i.e. from Sentinel-2) with SAR data (i.e. from Sentinel-1) leveraging various machine learning approaches for a limited number of crop types. However, these efforts normally train on individual pixels rather than leveraging information at a field level. 

Here we present Beyond Cloud, a product which is the first to leverage computer vision and machine learning approaches in order to provide fused optic and SAR based crop health information. Field level learning is especially well-suited for inherently noisy SAR datasets. Several use cases are presented over agriculture fields located throughout the United Kingdom, France and Belgium, where cloud cover limits optic based solutions to as little as 2-3 images per growing season. Preliminary efforts for additional features to the product including automated crop and soil type detection are also discussed. Beyond Cloud can be accessed via a simple API which makes integration of the results easy for existing dashboards and smart-ag tools. Overall, these efforts promote the accessibility of satellite imagery for real agriculture end users.

 
Climate change induced modifications of hydro-meteorological extreme events and their impacts on water resources for agriculture in the Mediterranean
Authors: Loukas Athanasios
Published: March 2021

It is common today to consider that climate is expected to change or even climate change is present and evident.  A changing climate leads to changes in the frequency, intensity, spatial extent, duration, and timing of climate extremes, and may result in unprecedented events. Changes in extremes of a climate variable are not always related in a simple way to changes in the mean of the same variable or a hydrological variable, and in some cases may be of opposite sign to a change in the mean of the variable.  Also, the changes vary from one geographical region to another.   In this review paper, examples of climate change impact studies on hydro-meteorological extremes, i.e. extreme precipitation, floods and droughts, in the Mediterranean region, are presented and discussed.  In this geographical area, agriculture is the main consumer of water, demanding 60-90% of the total water use. The impacts of the climate change induced modifications of hydro-meteorological extremes and water management practices on the availability of surface water and groundwater resources are also discussed.
High-resolution Sampling and Photogrammetry of the Permian-Triassic Boundary Within the Festningen Profile, Svalbard
Authors: Augland Lars Eivind , Planke Sverre , Zuchuat Valentin , Jones Morgan , Senger Kim , Betlem Peter , Birchall Tom , Hagopian William , Svensen Henrik
Published: March 2021

The Permian period ended with a mass extinction event about 252 million years ago. A likely trigger of the mass extinction was the eruption of large volumes of magma which had moved through the Tunguska Basin in Siberia. The renowned Festningen section in the outer part of Isfjorden, western Spitsbergen, offers a c. 7 km long nearly continuous stratigraphic section of Lower Carboniferous to Cenozoic strata, where the end-Permian extinction interval is well-exposed. Tectonic deformation associated with the Paleogene West Spitsbergen fold-and-thrust-belt tilted the strata to near-vertical, allowing easy access along the shoreline. The section is a regionally important stratigraphic reference profile and is a key locality for geologists visiting Svalbard. The main objective of our fieldwork in September 2020 was to collect closely spaced mudstone (0.25 to 1 m interval) and ash layer (6 layers of 0.5 to 1.5 cm thickness) samples across the Festningen Permian-Triassic boundary for chemostratigraphic and geochronological assessments. Carbon isotope data reveal a well-defined negative deltaC13 excursion in the lower part of the Vardebukta Fm. Zircons are present in most of the ash layer samples and these will be dated at the University of Oslo TIMS U-Pb Isotope Geology Laboratory. In this contribution, we will also present a new digital outcrop model of the P-Tr boundary section acquired using a UAV (Mavic 2 Pro, 20MP Hasselblad camera). During acquisition, the maximum drone speed was set to 1 meter/second (i.e., “tripod mode”), and photographs were taken automatically at set time intervals (e.g., 1 photo every 5 seconds ≈ meters). The digital outcrop model offers a pixel resolution of 7.27 mm/pixel. The Festningen model will be available online through the Svalbox.no geoscience data platform.