bluuebunny/crossref_metadata_2025 huggingface dataset:
A Mathematical Gaïagraphy: systematizing the new visualization of the Critical Zone in the Anthropocene.
Authors: Gaillardet Jérôme , Louis Quentin , Arènes alexandra
Published: March 2021

On the basis of the previous work of visualization of the Critical Zone (CZ) through a new conceptual scheme, we have developed mathematical equations in order to systematize this visualization. The previous work was the result of the collaboration between an architect, a geochemist (both authors of this new article) and a philosopher (Arenes, Latour, Gaillardet, 2018). The aim of this work was to address the lack of common representation of the Critical Zone among scientists and the public, and the lack of visualization of human disturbances in this CZ. For this new work, we are further developing the collaboration by including a mathematician in this new article. We kept the main structure of the gaïagraphy developed in the previous article, i. e. the drawing scheme placing the atmosphere in the center, the deep and weathered rocks at the periphery and the shallow soil in between, and a representation of biogeochemical cycles by a grammar of spirals. Thus, we worked on a more qualitative approach to draw the cycle of a chemical element in the CZ. To do this, we associate the reservoir size with the volume of the element found in it. Fluxes between the reservoirs are represented by spiral arcs whose length is proportional to the magnitude of the flux. In each reservoir, semi-circles encode for the residence time of the element. Other rules can be applied to reservoirs and fluxes, while keeping the systematic coding for applicability on multiple CZ observatories.

We present here the first results and the questions we wish to submit to the CZ and LTER communities. This work will validate or not the original conceptual scheme, testing also the capacity of mathematics to solve conceptual and philosophical questions.

 
Understanding and predicting climate extremes on land: The new frontier
Authors: Seneviratne Sonia
Published: March 2021

We live on land and are daily affected by land climate variations, but early climate pioneers often focused on ocean-climate interactions and ice-covered regions. With good reasons, since oceans cover two third of the Earth and are thus critical for the global climate, and because ice sheets have strongly varied over millennia and include key indices on past climate. However, recent research has increasingly shown that land climate, where we live, displays specific climate characteristics, which cannot be simply inferred from global climate responses. This is particularly the case for climate extremes, such as heatwaves and droughts. I will present recent evidence for these properties and some avenues for future research.

Land-climate interactions, which are modulated by vegetation, play a key role for climate variability on continents. This implies a fascinating interface between biological processes and climate physics. The limitation of water on continents, and the role of vegetation in the land water input to the atmosphere, implies very different water-cycle responses compared to what is seen on oceans: For instance, dry regions do not necessarily get drier, nor wet regions wetter under increasing greenhouse gas forcing. In addition, land climate can strongly deviate from global climate in other ways: During the so-called “hiatus period” in the early 2000s, changes in temperature extremes on land actually showed an amplified increase. Furthermore, key land processes are still insufficiently captured in state-of-the art Earth System Models (ESMs), such as land water effects on the global carbon cycle, and climate response to irrigation or land management.

Land processes are playing an increasingly central role in the development of pathways for climate mitigation consistent with the aims of the Paris Agreement, for instance related to afforestation or the development of bioenergy use in combination with carbon capture and storage. However, these scenarios often overlook biological and physical constraints for these land cover and land use changes, such as risks from climate extremes, including fire, in a warming world. ESM emulators for grid-cell responses may help to proof such scenarios in the needed rapid and safe transition to a net-zero CO2 world.
Conceptualising the effect of preferential flow on slow-moving landslides: from experiments to concepts and models.
Authors: Bogaard Thom
Published: March 2021

Precipitation is one of the main causes for the initiation or reactivation of deep seated slow moving landslides. Preferential flow paths can have multiple origins, they can be due to changes in soil water content such as desiccation, due to mechanical movement or due to biological activity. The overarching characteristic is that they strongly alter the hydraulic properties of the landslide material. This results in a complex hydrological behaviour of deep-seated slow moving landslides. Research has shown that for instance the porosity of the soil, the fissure distribution and fissure connectivity are very important to predict the behaviour of the hydrological response of precipitation within a landslide body. However, due to large heterogeneity of landslide lithology and spatial and temporal variation of a landslide, it is hard to model water levels in landslides. Cracks and fissures inside the landslide are the cause of preferential flow paths, which can work as infiltration networks to the groundwater, but also as drainage networks lowering the (perched) groundwater levels.

In the last decades, both methodological progress has been made and several case studies have been published. However, most are still somewhat anecdotic examples and a more overarching conceptualisation has not been made yet. In this overview I want to highlight the progress as well as obstacles and challenges ahead of us when assessing and quantifying the impact of preferential flow paths on the mechanisms of a slow moving deep-seated landslide and to improve our understanding and modelling of complex landslides.
Deep geothermal energy from the Cornubian Batholith: preliminary lithological and heat flow insights from the United Downs Deep Geothermal Power Project. 
Authors: Dalby Christopher , Shail Robin , Batchelor Tony , Cotton Lucy , Gutmanis Jon , Rollinson Gavyn , Wall Frances , Hickey James
Published: March 2021

SW England is the most prospective region in the UK for the development of deep geothermal energy as it has highest heat flow values (c. 120 mW m-2) and predicted temperatures greater than 190 oC at 5 km depth. The United Downs Deep Geothermal Project (UDDGP), situated near Redruth in Cornwall, is the first deep geothermal power project to commence in the UK. Two deviated geothermal wells, UD-1 (5058 m TVD) and UD-2 (2214 m TVD), were completed in 2019 and intersect the NNW-SSE-trending Porthtowan Fault Zone (PTFZ) within the Early Permian Cornubian Batholith.

The Cornubian Batholith is composite and can be divided into five granite types that were formed by variable source melting and fractionation [1]. These processes were the primary control on the heterogeneous distribution of U, Th and K that underpins heat production in the granite. Previous high resolution airborne gamma-ray data has demonstrated the spatial variation of near-surface granite heat production [2], and the CSM Hot Dry Rock Project (1977-1991) provided U, Th and K distributions to depths of 2600 m in the Carnmenellis Granite [3]. However, uncertainties in: (i) U, Th and K content in the deeper batholith, (ii) thermal conductivity are still challenges to modelling the high heat flow.

Preliminary evaluation of UD-1 downhole spectral gamma data (900-5057 m) indicates the presence of three major granite types on the basis of contrasting U and Th characteristics. QEMSCAN mineralogical analysis of cuttings (720 – 5057 m) demonstrates the overwhelming dominance of two mica (G1) and muscovite (G2) granites and little expression of biotite (G3) granites. U- and Th- bearing accessory minerals include monazite, zircon and apatite, with the appearance of allanite and titanite in the deeper granites. Representivity analysis between various cutting fractions show no systematic bias in the major mineral components.

There is a substantial increase in Th below 3000 m that indicates the deeper parts of the batholith are likely to contribute substantially to overall heat production. Monazite is the primary source for Th and has a close association with micas. Mineralogical, mineral chemical, whole-rock geochemical and coupled thermal conductivity analysis is ongoing to improve understanding of the construction of this part of the Cornubian Batholith and its implications for the regional thermal resource and sub-surface temperature evaluation.

References:
[1]Simons B et al. (2016) Lithos, 260: 76-94
[2]Beamish D and Busby J (2016) Geothermal Energy, 4.1:4
[3]Parker R (1989) Pergamon, 621.44
Geographical Information System Based Sensitivity Analysis Accurately Predicts Hydrocarbons Contamination Using Drastic Index and Multicriteria Analysis 
Authors: Babika Zaharatu , Kjeldsen Thomas
Published: March 2021

Among the numerous groundwater vulnerability assessment methodologies, the geographical information system-based DRASTIC model is the most widely used and have been found to achieve reliable results even in complex areas. However, hydrocarbon contamination cause by Anthropogenic activities has not previously being considered within these groundwater vulnerability assessment model.  This study proposes a new flexible approach for optimizing the identification of input data layers that can help identify vulnerability to hydrocarbon contamination through the principles of sensitivity analysis.The single-parameter (SA ) and map removal analysis(MA)  was employed to obtain effective weights for the  modified model, which were then implemented to improve efficacy Multi-criteria evaluation (MCE) techniques are part of a decision-making process for assigning weights of significance to each input layer to the DRASTIC model. The application is illustrated through a case study focussing on the city of Kano located in Northern Nigeria within west Africa .DRASTIC index model have seven paramters ,Depth of water table,net reharge ,Aquifer media ,soil media, Topography ,impact of vadose zone and hydrlauic conductivty.  The most sensitive parameters are depth of water (22.92%), net recharge, (25.98), impact of Vadose zone (27.07%),  The borehole data includes groundwater samples that were analysed for benzene, ethylbenzene and xylene (Betex) components of crude oil.  Accordingly, the results presented the highest hydrocarbon content (51.66477mg/l) in Dala (western Kano) due to the significantly high number of hydrocarbon sources such as under-storage tanks within the petroleum stations and automobile garages.
Quantitative texture analysis of alluvial gold: primary and secondary signatures
Authors: Gómez-Barreiro Juan , Barrios-Sánchez Santos , Compaña Prieto José Manuel , Morales Sánchez-Migallón Juan , dos Santos Alves Kelvin , Tettamanti Magdalena , Puente Orench Inés
Published: March 2021

The origin of gold nuggets (Au‐Ag alloys) is not completely understood. They crop out in placer deposits, potentially derived from a primary source (hydrothermal/magmatic). Meteorization, erosion and transport of primary gold deposits result in the liberation of a variety of particle size. Recent investigations suggest that both primary and secondary microstructural features may be preserved and could be related to deformation during transport, recrystallization and primary formation. Besides, the contribution of biological mechanisms (biomineralization) may have played an important role during secondary growth in some nuggets. In many cases, there is no clear evidence to distinguish between supergenic and hypogenic gold, so texture information could be excellent information to constrain the origin. Besides, it has been demonstrated that crystallography controls the de‐alloying processes in gold nuggets. This mechanism, that transforms the primary Au–Ag alloys into pure gold by preferential dissolution of Ag along crystal boundaries, could be determined by variations on texture, a factor never explored before, which may explain the dispersion in de‐alloying values in the same deposit.

 

In this case we have explored a selection of gold nuggets collected in the W sector of the Iberian Massif (Spain), representing the principal morphological types. As a non-destructive technique neutron diffraction appears as the technique of choice in this case. Beside, neutrons absorption is very low so that large samples could be investigated. Samples were analyzed in transmission at ILL (Grenoble) for texture. Quantitative texture and gold crystallinity was calculated using Rietveld method as implemented in Maud software (EWIMV). Mono- and polycrystalline nuggets and alloy composition were clearly identified in each particle with this technique. Our results show a close correlation between the morphology (i.e. transport length) of the particle and the crystallographic results, particularly for fibrous and discoid shapes (i.e. Zingg, Corey shape factor), what could be used to develop better transport models (distance-to-bedrock sources) and understand multisource gold placer assemblages. 
Inflight performance of the state-of-the-art BepiColombo MORE radio-tracking system 
Authors: Cappuccio Paolo , Iess Luciano , Durante Daniele , di Stefano Ivan , Racioppa Paolo , Asmar Sami
Published: March 2021

The ESA/JAXA mission BepiColombo, launched on 20 October 2018 is in cruise towards Mercury and will arrive at Mercury in 2025 to investigate its surface, interior structure and magnetosphere. The Mercury Orbiter Radio-science Experiment (MORE) onboard the Mercury Planetary Orbiter (MPO) aims at determining the gravity field, the rotational state and librations of the planet, using precise tracking of the spacecraft during its orbital phase around Mercury. Range and range-rate measurements collected during the cruise phase will be used to test the theory of general relativity starting in March 2021. The MORE experiment exploits two-way multifrequency microwave links from ESA and NASA: two downlinks in X- and Ka-band coherent with the X-band uplink and one Ka-band downlink coherent with the Ka-band uplink. The range-rate and range measurements accurately BepiColombo’s line-of-sight velocity and the round-trip light-time of the signal, respectively. The calibration of the dispersive plasma noise component through the combination of the X/X, X/Ka and Ka/Ka links and the use of water vapor radiometers to correct for the path delay due to Earth’s troposphere will result in an accuracy of ~3 µm/sec (at 1000-s integration time) on the Doppler and centimeter-level range accuracies. We report on the analysis of dedicated tests executed on range and Doppler data collected by ESA and NASA stations at X and Ka-band. The comparison of the observed noise with the predictions shows results exceeding the expectations. In particular, the 24 Mcps pseudo-noise modulation of the Ka-band carrier, enabled by MORE’s KaT transponder built by Thales Alenia Space Italia, provided two-way range measurements accurate to ~3 cm with just 4 s integration time, at a distance of 0.7 AU, September 2021, and 1.3 AU, November 2021. Under favorable weather conditions, the range rate has shown an accuracy of 25 µm/s at 10 s integration time, in line with the expected end-to-end performance. Under unfavorable weather conditions the performance was slightly over the requirements. We must remark that calibrations from water vapor radiometers were not available during these tests and only GNSS calibration were applied.
Effect of climate change on wildfires in Fennoscandia
Authors: Backman Leif , Aalto Tuula , Aalto Juha , Markkanen Tiina , Thölix Laura , Lasslop Gitta
Published: March 2021

The climate in the Boreal area is warming at a pace that is exceeding the global average. Both temperature and precipitation is projected to increase due to climate change. The gross primary production in the forested area is also projected to increase, as well as the soil respiration. The burned area is sensitive to the meteorological forcing and the risk of ignition depends on the amount and properties of the litter. Overall climate change has a potential to increase the fire risk in the Boreal forests.

The effects of projected climate change on forest fires in Fennoscandia, and in parts of Russia adjacent to Finland, were simulated with the JSBACH-SPITFIRE. JSBACH is the land model in the Earth system models of the Max-Planck Institute for Meteorology. SPITFIRE is a mechanistic fire model, driven by meteorology, vegetation cover, fuel load and fuel properties. The model simulates fire risk, number of fires and burned area fraction. SPITFIRE uses ignition rates and distinguishes between ignition events caused by lightning and humans. Ignition events result in fire only when enough fuel is present, and the fuel is sufficiently dry. The JSBACH-SPITFIRE model was driven by downscaled and bias corrected meteorological data from the EURO-CORDEX initiative, for the period from 1951 to 2100. The model domain was the land area within 55-71°N and 5-38°E. A subset of the EUR-44 domain was regridded to 0.5° resolution for our model domain. The global driving models used for producing the EURO-CORDEX data used here were CanESM2, CNRM-CM5, MIROC5. We selected driver models that represent mid-range regarding the projected change in temperature and precipitation for Finland under RCP4.5 and RCP8.5. We used daily bias corrected data of precipitation and temperature from 1951 to 2100 for both RCP4.5 and RCP8.5 climate change projections. In addition, daily data of relative humidity, wind speed, longwave and shortwave radiation were used for the historical (1951-2005) and scenario period (2006-2100).

Preliminary results indicate that the increase in temperature, which affects the drying rate of the fuel, is the major factor for driving the changes in forest fires in the simulations.
Identifying parameters on genesis of coronal phases at olivine-plagioclase contact: A comparison from different geological terrane
Authors: Banerjee Meenakshi , Adak Vedanta , Dutta Upama
Published: March 2021

Corona texture between olivine-plagioclase is a common phenomenon in metabasic rocks and has been reported from different geological terrane of the world. However, the documented coronal phases from these terrane show significant variation in terms of number and composition. In this study, we have tried to explore the effect of different parameters like pressure, temperature, reactant bulk composition, availability of fluid, chemical potential gradient etc. on the genesis of such distinct coronal minerals. To address this question, we have compared three coronal assemblages developed between olivine and plagioclase from published literature (Gallien et al. 2012; Banerjee et al. 2019; Adak & Dutta, 2020). These three samples represent different terrane and have distinctly separate geological evolutionary history that led in formation of the texture. The samples are – i) #CGGC, a mafic intrusive from Chotanagpur Granite Gneissic Complex, India (Adak & Dutta, 2020); ii) #GTSI, an olivine bearing mafic dyke from Granulite Terrane of South India (Banerjee et al. 2019); and iii) #VFH, a troctolitic gabbro from Valle Fértil and La Huerta range, Argentina (Gallien et al. 2012). The layers in coronae of #CGGC and #GTSI are defined by three phases of separate composition; orthopyroxene and amphibole are common, but #CGGC contains spinel and #GTSI contains magnetite. Whereas, #VFH contains four phases, clinopyroxene in addition to orthopyroxene, spinel and amphibole. Besides evaluation of reactant composition and their effect, our methodology also incorporates Schrienemaker’s analysis through P-T and chemical potential diagrams. Considering the chemistry of both the reactant and product phases we have used a simplified CMASH system and calculated μCaO–μH2O, μMgO–μH2O, μCaO–μMgO diagram along with petrogenetic grid for each sample. The results show that along with change in P-T, factors like initial composition of the reactant minerals, behaviour of the system during reaction (open/closed) and P-T-t path of evolution also play significant role in determining the products in coronae formed from the reactant olivine and plagioclase.

 
Canopy structure and stress induced changes in chlorophyll fluorescence – a mesocosm experiment
Authors: Hammerle Albin , Migliavacca Mirco , Spielmann Felix , Pacheco-Labrador Javier , Wohlfahrt Georg
Published: March 2021

Solar radiation absorbed by chlorophyll in plants is either used for photosynthesis, dissipated as heat or is re-emitted as fluorescence at a slightly higher wavelength. Sun induced chlorophyll fluorescence (SIF) has thus the potential to act as a sensitive indicator for early stress detection in ecosystems. SIF signals at the top of the canopy are however influenced by canopy structure and not only by plant physiology, due to light scattering and (re)absorption.

In this study we present the first results of a mesocosm experiment on the effect of drought stress on chlorophyll fluorescence in two plant stands differing in their canopy structure. In total we investigated 24 plots of planophile (Trifolium repens) and erectophile (Lolium perenne) plant stands. 12 plots acted as a control plots, while the remaining 12 plots underwent a progressively intensifying drought stress treatment. During the course of the experiment regular measurements of SIF using a passive spectrometer system were conducted. Furthermore, active chlorophyll fluorescence measurements with a multiplexed field spectrometer system were used to derive the maximum PSII efficiency (Fvm) and non-photochemical quenching (NPQ). Ancillary measurements included meteorological, leaf physiological, soil water and canopy structure variables.

The drought treatment led to a relatively stronger decrease in NDVI and a relatively higher increase in PRI in the Trifolium repens stand, which also experienced a more pronounced increase in NPQ, especially during hot days. For both stands surface temperatures were clearly higher in the treatment groups, with a larger effect in the Trifolium stand. SIF-yield (SIF/aPAR) did remain more or less constant or increased slightly for the control groups. In both stands it dropped towards the end of the experiment for both treatment groups at very low soil water content levels, about at the same time when the active chlorophyll fluorescence measurements started to indicate persistent reductions in Fvm. The relative decrease in SIF and SIF-yield for the treatment groups was not significantly different between the two stands.
Numerical modelling of sediment transport in a channel bend with floating units
Authors: Maskey Diwash Lal , Ruther Nils
Published: March 2021

Floating units/booms are used to trap or guide floating debris in watercourses. In a relatively shallow depth, these floats could affect the velocity distribution, sediment transport and channel bed deformation.  A three-dimensional non-hydrostatic numerical modelling was performed in a 180 degree channel bend with floats to see the effects in flow distribution and bed deformation as a conceptual study. Different configurations of the floats were simulated. The results showed that the flow velocity increased and deposition decreased at the inner bank of the bend. Use of floating units could be studied to alter sediment deposition pattern and sediment transport phenomenon in watercourses.
Assessing the sensitivity of small catchments to an extreme event in the North-west Himalayas
Authors: Sarkar Arkaprabha , Singh Vimal
Published: March 2021

Smaller systems have thresholds lower than those of larger ones. Therefore, the response of a small change can be easily observed in small catchments where a larger system might not respond.

In this study, we investigated sub-catchments of a small 4th order Pranmati River Catchment, located in the North-west Himalayas; it is the part of the Ganga River System. We selected eight sub-catchments of 1st to 3rd order with area not more than 16 km2 and analyzed their response to high-intensity rainfall. We calculated drainage density, length of overland flow, infiltration number, and constant of channel maintenance to analyze their behavior in terms of infiltration and surface runoff. The results show that two of the sub-catchments show tendency of low infiltration and higher surface runoff compared to the other sub-catchments. To validate our results, we compared them with the observations and available data of a highly localized high-intensity precipitation event that occurred in July 2018 within the catchment. During this event, there was focused rainfall in one of the sub-catchments that initiated a flash flood. The flood propagated from that sub-catchment along the trunk channel while all other sub-catchments suffered negligible impact. A significant increase in channel width has been observed along the path of the flood. We ran simulations of storm events in HEC-RAS for various rainfall patterns within the given time interval to replicate the event.

The hydrological simulation of basin-wide uniform rainfall with a Gaussian temporal distribution shows high overland sheet flow in these basins whereas the rest of the basin showed channel flow and low surface runoff. One of these two catchments was the initiation point of the flood event. The results indicate the high sensitivity of the basins and their contrasting responses under similar forces. Minor differences in the values of geomorphic parameters which are inconsequential in the case of large catchments become significant for smaller catchments. It also highlights the degree of spatial heterogeneity of rainfall and the inconsistency of the presently available precipitation datasets.
Natural and artificial radioactivity of soil of the Arctic part of Western Siberia
Authors: Mezina Kseniya , Melgunov Mikhail , Belyanin Dmitriy
Published: March 2021

To assess the levels of radioactivity, the soils of the Arctic region of Western Siberia were studied. The content of Cs-137 in the soils of the studied region ranges from 2 to 9 Bq/kg, with an average value of 4 Bq/kg.

The average contents of natural radionuclides (U, Th and K-40) in soils are determined by the radioactivity of the parent rocks. The radioanalytical results showed that the average Th content is 2.8 (0.3-6.7) ppm; U – 2.0 (0.5-6.6) ppm, K-40 – 233 (16-473) Bq/kg in the soils.

This work was supported by the Russian Science Foundation grant (project No 18-77-10039). Analytical studies were carried out at the Center for multi-elemental and isotope research SB RAS.
Atmospheric response to SST tendancy in the Eastern topical Atlantic in July-August
Authors: Wane Dahirou , de Coëtlogon Gaëlle , Alban Lazar , Wade Malick , Gaye Amadou T.
Published: March 2021

The objective of this work is to understand how the seasonal tendances of the tropical Atlantic SST influence the migration of the Intertropical Convergence Zone (ITCZ) and the West African precipitation associated with it. For this we carried out different sensitivity tests to the SST, climatological, with the regional atmospheric model WRF-ARW. Our results, based on the July-August period, show a strong influence of SST anomalies in the Dakar Nino (DN) and Atlantic cold tongue (ACT) regions on the marine ITCZ and West African precipitation. Above the ocean, the cooling of the tropical northeast Atlantic induces a strong reduction in precipitation north of 10°N, associated with the southward displacement of the ITCZ which is located between 5°-10°N with a slight increase in rains. On the other hand, the warming of the SST of the tropical south-eastern Atlantic induces an increase in marine precipitations, with a maximum centered on 5°N, explained by the location of the ITCZ further south than that associated with the cooling in the region of DN. On the continent, the influence of these SST tendances is characterized by the presence of a zonal dipole of rainfall anomalies over the Sahelian regions. The SST cooling effect in the DN region is more marked in the western Sahel, particularly in Senegal, with a sharp drop in rainfall in this region. While that of warming in the LEF region is more marked in the Sahel, which also induces a strong reduction in the intensity of the rains in this region. However, the combined experience of these two type anomalies shows a dipole of rainfall anomalies over the ocean and over the continent. This dipole is characterized by a decrease (increase) in Sahelian (Guinean) rainfall. Our results also show that, for all simulations, the increase (reduction) in precipitation is more explained by the convective (non-convective) part of the rain. The influence of the SST of DN contributes 40% to 100% on the decrease in rainfall in the West Sahel, while the SST of the ACT reduces rainfall in the eastern Sahel by 40% to 100%. Thus, this work underlines the importance of taking into account the effect of the seasonal anomaly of the SST of DN on Sahelian precipitations in forecasting models.
Microbial dispersal throgh dead-end cavities
Authors: Scheidweiler David , Bordoloi Ankur Deep , de Anna Pietro
Published: March 2021

Predicting dispersal patterns is important to understand microbial life in porous media as soils and sedimentary environments. We studied active and passive dispersal of bacterial cells in porous media characterized by two main pore features: fast channels and dead-end cavities. We combined experiments with microfluidic devices and time-lapse microscopy to track individual bacterial trajectories and measure the breakthrough curves and pore scale bacterial abundance. Escherichia coli cells dispersed more efficiently than the non-motile mutants showing a different retention in the dead-end pores. Our findings highlight the role of diffusion dominated dead-end pores on the dispersal of microorganisms in porous media.
Contrasting patterns of vegetation compositing and species diversity over 22 000 years in two adjacent artic-alpine catchments
Authors: Topstad Lasse , Clarke Charlotte , Mangerud Jan , Svendsen John-Inge , Haflidason Haflidi , Greve Alsos Inger
Published: March 2021

Throughout the late Quaternary, the vegetation of Polar Urals (Russia) endured dramatic changes in climate, but still seems to have maintained a high, yet compositionally dynamic species richness. A recent study of Lake Bolshoe Schuchye (187 m a.s.l., Clarke et al. 2019 Sci. Rep.) suggests that this region was an important refugium for arctic-alpine plant taxa during the Early Holocene forest expansion. Whether the survival of taxa and the turnover of species and functional groups was consistent throughout the region or dependent on local conditions remains unknown. Here, we present reconstructed plant assemblage dynamics spanning the past 22,000 years based on metabarcoding of sedimentary ancient DNA (sedaDNA) cored from Maloe Schuchye (287 m a.s.l.). The record is compared to the neighboring lake Bolshoe Schuchye in terms of how taxonomic richness and composition of functional groups developed through time. Throughout the study period, several large-scale vegetation changes occur in both cores, however, identified at slightly delayed time intervals for the higher altitude site Maloe Schuchye, based on the CONISS clustering. The total richness was higher in Maloe Schuchye (274 taxa) compared to Bolshoe Schuchye (191 taxa), and the average richness was higher in Maloe Schuchye throughout the period. The largest difference in taxonomic richness between the two lakes was during the Last Glacial Maximum (LGM) and Late Glacial periods, when Maloe Schuchye had considerable higher richness of forbs and graminoids than Bolshoe Schuchye. Despite these contrasting diversity patterns, the time of arrival of taxa highly align in the two records. Thermophilic plant taxa occur slightly earlier in the lower altitude Bolshoe Schuchye lake record, as expected. Further, the survival and persistence of arctic-alpine taxa is similar in the two catchments, confirming the importance of this region for long-term survival or arctic-alpine species.
How to embrace big data and uncertainties within reasonable time constraints? A detailed flood study in Flanders
Authors: Leyssen Gert , van Uytven Els , Blanckaert Joris , Adams Roeland , Franken Tim , Nossent Jiri , Pereira Fernando
Published: March 2021

Progressing towards a sustainable society implies the availability of reliable boundary conditions for various hydrodynamic flood models, including an extensive consideration of uncertainties. With an ever growing availability of data and models, the uncertainty sources are constantly increasing. Hence, an elaborate uncertainty analysis strategy has become a must. One way to deal with part of this uncertainty is by applying an ensemble approach, using different hydrological models in combination with various climate scenarios. However, impact modellers may find the growing number and the increasing length of input series for hydraulic models more challenging, since computing time, reliability of the analysis and project deadlines can cause a conflicting situation. In this context, there is a need for approaches that offer a compromise between computing the vast amount of long input series and adequately addressing the uncertainties within a reasonable time span. We present an approach which reduces the computation time, but simultaneously recognises the importance of robust results and the consideration of the different sources of uncertainty. By a stratification of the probability domain for extreme events (discharges, water levels,…) a set of hydrodynamic boundary conditions is generated. Each of these synthetic events gets a probability of occurrence, which changes according to either the considered confidence level or the considered ensemble member. In addition to the stratification approach, a tool for selecting synthetic events for design is developed. This tool allows end-users to create a subset of synthetic events which can be used as design events for a specific area and are representative for the full set of events. The approach is demonstrated for the River Dender catchment in Flanders using 40 years of hydro-meteorological data, an ensemble of 3 hydrological models and a detailed hydraulic model.
Topographic amplification of crustal subsidence by the rainwater load of the 2018 heavy rain in SW Japan
Authors: Arief Syachrul
Published: March 2021

The huge amount of water vapor in the atmosphere caused disastrous heavy rain and floods in early July 2018 in SW Japan. Here I present a comprehensive space geodetic study of water brought by this heavy rain done by using a dense network of Global Navigation Satellite System (GNSS) receivers. 

First, I reconstruct sea level precipitable water vapor above land region on the heavy rain. The total amount of water vapor derived by spatially integrating precipitable water vapor on land was ~25.8 Gt, which corresponds to the bucket size to carry water from ocean to land. I then compiled the precipitation measured with a rain radar network. The data showed the total precipitation by this heavy rain as ~22.11 Gt.

Next, I studied the crustal subsidence caused by the rainwater as the surface load. The GNSS stations located under the heavy rain area temporarily subsided 1-2 centimeters and the subsidence mostly recovered in a day. Using such vertical crustal movement data, I estimated the distribution of surface water in SW Japan. 

The total amount of the estimated water load on 6 July 2018 was ~68.2 Gt, which significantly exceeds the cumulative on-land rainfalls of the heavy rain day from radar rain gauge analyzed precipitation data. I consider that such an amplification of subsidence originates from the selective deployment of GNSS stations in the concave places, e.g. along valleys and within basins, in the mountainous Japanese Islands.
Using the molecular composition of dissolved organic matter in groundwater to assess the functional stability of subsurface ecosystems
Authors: Benk Simon , Lehmann Robert , Totsche Kai Uwe , Gleixner Gerd
Published: March 2021

With surface systems changing rapidly on a global scale, it is important to understand how this will affect groundwater resources and ecosystems in the subsurface. The molecular composition of dissolved organic matter (DOM) integrates essential information on metabolic functioning and could therefore reveal changes of groundwater ecosystems in high detail. Here, we evaluate a 6-year time series of ultrahigh-resolution DOM composition analysis of groundwater from a hillslope well transect within the Hainich Critical Zone Exploratory, Germany. We predict ecosystem functionality by assigning molecular sum formulas to metabolic pathways via the KEGG database. Our data support hydrogeological characterizations of a compartmentalized fractured multi-storey aquifer system and reveal distinct metabolic functions that largely depend on the compartment’s relative surface-connectivity or isolation. We show that seasonal fluctuation of groundwater levels, coinciding with cross-stratal exchange can substantially impact the local inventory of functional metabolites in DOM. Furthermore, we find that extreme conditions of groundwater recharge following pronounced groundwater lowstand cause strong alterations of the functional metabolome in DOM even in aquifer compartments, which usually show minimal variation in DOM composition. Our findings suggest that bedrock groundwater ecosystems might be functionally vulnerable to hydrogeological extremes.
Freshwater Salinization Syndrome:  Emerging Global Problem and Risk Management
Authors: Kaushal Sujay , Likens Gene , Mayer Paul , Pace Michael , Reimer Jenna , Maas Carly , Galella Joseph , Utz Ryan , Duan Shuiwang , Kryger Julia , Yaculak Alexis , Boger Walter , Bailey Nathan , Haq Shahan , Wood Kelsey , Wessel Barret , Collison Daniel , Aisin Belie
Published: March 2021

Freshwater salinization is an emerging global issue impacting safe drinking water, ecosystem health and biodiversity, and infrastructure.  The complex interrelationships between salt ions and chemical, biological, and geologic parameters and consequences on the natural, social, and built environment are called Freshwater Salinization Syndrome (FSS).  We analyze and discuss the expanding magnitude and scope of FSS including its discovery of widespread geographic importance in humid regions and connections to human-accelerated weathering and mobilization of ‘chemical cocktails,’  We also present empirical data analyses illustrating changes in FSS and its water quality impacts across time and space. We outline several frontiers in FSS research, and we also identify new management strategies and tradeoffs.   
Volcano flank dynamics: breakthroughs delivered by space technologies
Authors: Puglisi Giuseppe
Published: March 2021

Flank dynamics is an ensemble of phenomena observable in many volcanoes, caused by shallow (e.g. material erosion) or deep sources (e.g. tectonics or magma dynamics). Whatever its origin, the most evident effect of flank dynamics is the continuous/steady movement of the flanks of the volcano. The interaction between gravity, tectonics and magma dynamics produce deep-seated, steady-state movement of large sectors of the volcanoes (sometimes called “persistent flank motion” or “volcanic spreading”), whose effects may be severe, either when it evolves in sudden transient acceleration (producing flank collapses or landslides) or when the steady movement damages essential infrastructures or inhabited areas.

Before space-based observations begun, the knowledge of flank dynamics was limited in terms of areal dimension, magnitude and evolution. Since the 90s, first the GPS, then the SAR interferometry have produced a dramatic shift in the capacity to measure ground deformations at the scale of the volcano. GPS and InSAR now give a complete picture of the persistent flank motion and allow inferring the processes inducing this phenomenon. All this impacts the ability to improve the Hazard Assessment and Risk Reduction related to the persistent flank dynamics. Some worldwide examples are reported in the presentation, among of which from Supersite volcanoes. In particular, Mt. Etna offers the opportunity to make some considerations on the benefit of these improvements in hazard assessment of the flank dynamics.
Functionality of Soil Microorganisms in Bio-conservation of Water and Soil
Authors: Gharemahmudli Sudabeh , Sadeghi Seyed Hamidreza , Najafinejad Ali
Published: March 2021

Abstract: Soil erosion is a major concern worldwide and serious eco-environmental problem and an important driver of soil loss and water sources. Hence, it is necessary to provide appropriate biological solutions and implement proper measures aimed at controlling soil erosion and runoff generation. Application of soil amendments and additives is one of the technical-managerial approaches considered to enhance soil stability against degradation agents. One of the new and biological technique in the conservation and management of soil and water resources is the use of native soil microorganisms extracted from the same area. Soil microorganisms are resistant to various environmental stresses such as high temperature, drought, UV, freezing and other stresses. In response to extreme and variable conditions, consortia of several species can develop firm layered structures, microbial mats, or biofilms. The inoculated soil microorganisms, especially bacteria and cyanobacteria through their polysaccharide and exopolysaccharide secretions, cellular elasticity, connecting to soil fine particles via cell adhesiveness. They also stay in the space between proliferation and developing filament networks and binding to aggregates. Besides water abstraction of rainfall and the creation of surface soil microchannels, they increase soil permeability and resistance stress which can tackle the effects of raindrop splash through water absorption and creation a protective layer around soil particles. It ultimately reduces runoff yield and soil loss. Soil microorganisms also can contribute considerably to soil organic matter and exert critical control over soil organic carbon stabilization in the global carbon cycle, soil recovery and stability as well as increase nutrient accumulation and soil fertility. According to the study conducted by the authors, by extraction and proliferation of soil microorganisms from an area under freezing-thawing conditions, their performance was evaluated in laboratory conditions. The results of their research showed that the direct inoculation of soil microorganisms into the soil decreased mean runoff volume by 73% and increased time to peak by 56%. Further, a decrease of some 78% in mean sediment concentration and a decrease of 89% in total soil loss were ascertained. Hence, creating artificial biological soil crusts by native soil microorganism inoculation is novel step in achieving biological tools to increase soil stability against soil erosion. The direct inoculation of soil microorganisms therefore could be supposed as a rapid, persistent, environmentally sound, economically efficient, and technically appropriate biological tool for conserving soil and water resources.
First Report of the WMO COVID-19 Task Team on Meteorological and Air Quality (MAQ) factors affecting the COVID-19 pandemic.
Authors: Omumbo Judy
Published: March 2021

The World Meteorological Organization (WMO) Research Board has set up an interdisciplinary and international Task Team to respond to the challenge of providing timely decision support and relevant knowledge on Meteorological and Air Quality (MAQ) factors affecting the SARS-CoV-2/COVID-19 pandemic. The Task Team aims to provide decision makers and the public with a rapid summary of the state of knowledge regarding potential MAQ influences on SARS-CoV-2/COVID-19; to offer general technical guidance for researchers and service providers who wish to consider MAQ data in their analyses, estimates, predictions and projections of COVID-19 risks. The work of the task  motivated both by the global relevance of the subject and by the staggering number of papers and pre-prints currently available, which emphasizes the need for careful review and communication of the state of the science. This first  report presents a summary of key findings of the review to date, as informed by peer reviewed literature.

 

A key finding is that the underlying mechanisms that drive seasonality of respiratory viral infections are not yet well understood. To date, COVID-19 transmission dynamics appear to have been controlled primarily by government interventions rather than meteorological factors. Respiratory viral infections frequently exhibit some form of seasonality, particularly in temperate climates and some evidence from laboratory studies of SARS-CoV-2, suggests that the virus survives longer under cold, dry, and low ultraviolet radiation conditions. There is also evidence that chronic and short-term exposure to air pollution exacerbates symptoms and increases mortality rates for some respiratory diseases and this is consistent with early studies of COVID-19 mortality rates. However, there is no direct, peer reviewed evidence of pollution impacts on the transmission of SARS-CoV-2 at this time. Process-based modeling studies anticipate that COVID-19 transmission may become seasonal over time, suggesting Meteorology and Air Quality (MAQ) factors may support monitoring and forecasting of COVID-19 in the coming months and years.

 

Additional research quantifying links between MAQ factors and COVID-19 is needed.
Working with an Indigenous Advisory Council to facilitate effective communication and collaboration between researchers and Arctic communities 
Authors: Herman-Mercer Nicole , Cozzetto Karen , Musselman Keith
Published: March 2021

The Arctic Rivers Project is a National Science Foundation – Navigating the New Arctic funded project aimed at increasing our understanding of the impacts of climate change on rivers, fish, and Indigenous communities across the Northern Alaska and the Yukon River Watershed in Alaska and Canada.  This will be accomplished through water-quality monitoring, a variety of modeling activities, and the development of narratives of change from community members themselves.  Combined these methods will create storylines of climate change in the arctic.  Storylines combine experiential narrative information with model outputs to make the predicated future more tangible regarding potential impacts.  The project team is comprised of researchers from the natural and social sciences as well as the modeling community and two Indigenous organizations focused on science, outreach, and engagement.  To increase the research team’s ability to co-produce knowledge with Indigenous communities across a large study domain we are working with an Indigenous Advisory Council (IAC).  The IAC is comprised of 11 Indigenous community members, leaders, elders and students representing diverse communities across our study domain. The IAC meets via online video conferencing monthly to tackle tasks such as developing knowledge co-production and inclusion and protection of Indigenous Knowledge protocols to guide the project.  Additionally, the IAC is working with a subset of the research team to create the goals, objectives, and agenda for an Arctic Rivers Summit that will bring together Tribal and First Nation resource managers, Arctic and Boreal community members, and academic, Indigenous, federal, state, and provincial researchers to unify the state of knowledge on Arctic Rivers as a community of observers, investigators, knowledge holders, and stewards.  This presentation will discuss the steps taken to form the IAC, the role of the IAC in guiding project implementation, providing advice, and facilitating connections with Indigenous communities.  It is our hope that we may provide an example of successful implementation and design to communicate and co-produce knowledge with communities across a large study domain from which other projects may learn.