bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of geoelectrical monitoring of the critical zone processes on microfluidic chips
Authors: Rembert Flore , Stolz Arnaud , Roman Sophie , Soulaine Cyprien
Published: February 2023

We miniaturize the low-frequency (<1kHz) geoelectrical acquisition using advanced micro-fabrication technologies to investigate coupled processes in the critical zone (CZ). With this innovation in the experimental acquisition, we focus on the development of the complex electrical conductivity monitoring with the spectral induced polarization (SIP) method. The interpretation of the SIP signal is based on the development of petrophysical models that relate the complex electrical conductivity to structural, hydrodynamical, and geochemical properties or distributions. State-of-the-art petrophysical models, however, suffer from a limited range of validity and presume too many microscopic mechanisms to define macroscale parameters. Thus, direct observations of the underlying processes coupled with geoelectrical monitoring are keys to deconvolute the signature of the biochemical-physical mechanisms and, then, developing more reliable models. Microfluidic experiments enable direct visualization of flows, reactions, and transport at the pore-scale thanks to transparent micromodels coupled with optical microscopy and high-resolution imaging techniques. Micromodels are a two-dimensional representation of the porous medium, ranging in complexity from single channels to replicas of natural rocks. Cutting-edge micromodels use reactive minerals to investigate the water-mineral interactions involved in the CZ. In this work, we propose a new kind of micromodels equipped with four aligned electrodes within the channel for SIP monitoring of calcite dissolution, a key multiphase process of the CZ involved in karstification. We highlight the strong correlation between SIP response and dissolution through electrical signal examination and image analysis. In particular, degassed CO2 bubbles generated by the dissolution play a major role.  Our technological advancement brings a deeper understanding of the physical interpretation of the complex electrical conductivity and will provide a further understanding of the CZ dynamic processes through SIP observation.
Mind the gap: leveraging wind-gaps to identify competing river piracy events in southwestern Germany
Authors: Peifer Daniel , Beer Alexander , Glotzbach Christoph , Ehlers Todd A.
Published: February 2023

Stream piracy has been central in explaining landscape evolution since W. M. Davis first introduced the concept. Reconstructions of drainage histories routinely invoke rerouting of an antecedent river to a lower adjacent stream. However, despite decades of analytical and computational progress, inferring discrete river reorganisation events remains challenging. In this contribution, we document how the transient drainage history of a region can be reconstructed using digital topography. Our premise is that previous topographic analyses neglect older stream piracy events. For example, in a typical retreating escarpment scenario, such as in southwestern Germany, erosion is concentrated in steep escarpment-draining rivers that occasionally capture plateau areas. These captures are readily detectable using topographic archives such as paired "area-gain/area-loss" profiles in χ-elevation space and mobile knickpoints at or upstream of capture points. However, such topographic archives decay as channels adjust to changes in drainage area, and thus many captures remain 'undetected' after escarpment retreat.Here we use wind-gaps, a unique post-capture landform that is more prone to persist due to its position as a drainage divide, to identify otherwise 'undetectable' prior piracy events. We take advantage of TopoToolbox's DIVIDEobj algorithm to extract the drainage divide network of a landscape as a whole (i.e., every ridgeline separating neighbouring streams). From this, we calculate the ratio between the elevation of a segment in the divide network and the average elevation of neighbouring divides. We identify wind-gaps as (i) low-elevation divides confined on both sides by neighbouring higher divide segments, which (ii) are also characterised by low across-divide differences in relief. This approach provides insight into the drainage evolution history of South German Scarplands. The tectonic development of the Upper Rhine Graben led to an incipient northwest-oriented drainage that became progressively more erosive, especially since the Late Miocene. These northwest-draining rivers, such as the Neckar River, expanded their drainage areas via multiple discrete piracy events. This sequence of capture events led to the reversal of southern German rivers that originally drained to the southeast (towards the Danube). Our results identify tens of piracy events considerably downstream of the current divide separating the Neckar and Danube catchments that otherwise would not have been identified and put in temporal context. These results are in contrast to previous approaches that could only identify capture events in the vicinity of the current divide. In areas adjacent to wind-gaps and along 'reversed' and 'beheaded' streams, we explore the morphological relationships with the relative timing of the stream piracy events. Taken together, these results lead to a more comprehensive treatment of drainage history from topographic data.
Potential Water Resources in the North-Eastern Adriatic Sea
Authors: Giustiniani Michela , Busetti Martina , Dal Cin Michela , Barison Erika , Cimolino Aurélie , Brancatelli Giuseppe , Baradello Luca
Published: February 2023

Increasing demand for freshwater requires the identification of additional and less-conventional water resources. Amongst these, offshore freshened groundwater is considered a new opportunity to face increasing water demand and has been studied in different parts of the world. Here we focus on the north-eastern Adriatic Sea, where offshore aquifers could be present as a continuation of onshore aquifers. Geophysical data, especially offshore seismic data, as well as onshore and offshore well data were integrated and interpreted to characterize the hydrogeological setting via the interpretation of seismo-stratigraphic sequences. Two areas located in the proximity of the Tagliamento and Isonzo deltas were studied. Well and seismic data suggest that Quaternary sediments, extending from onshore to offshore areas, represent the most promising from an offshore freshwater resources point of view. Firstly, onshore well data confirm the presence of freshwater aquifer systems in proximity to the coastline, supporting the hypothesis of their continuation offshore. Secondly, during the glacial periods, a drop in sea level (about -120 m with respect to today during the Last Glacial Maximum ), provided the total emergence of the northern Adriatic Sea, that represented a fluvial plain, allowing the storage of freshwater. Moreover, a lower sea level position could lead to a higher groundwater gradients towards offshore areas. On the contrary, during the interglacial ones, the sea level was some meters higher than the present one (about +8 m during the last transgression in the Middle/Late Pleistocene), with mainly starved conditions. During the deglaciation phases, the fluvial drainage fed by melting glaciers produced the deposition of sediment above the plain. Below these sediments, the several kilometres thick pre-Quaternary carbonate and terrigenous sequences seem to host mainly salty waters.
Khalat al-Saharij - An Iron Age Small Site and Long Anthropogenic Effect on the Soil
Authors: Ackermann Oren , Marcus Jenny , Fišer Jan , Itach Gilad , Janovský Martin , Wieler Nimrod
Published: February 2023

Ancient anthropogenic long-term effects on soil chemical composition is a well-known phenomenon in large archaeological sites. In the current presentation, this effect will be shown in Khalat al-Saharij, a small site located in central Israel, in the footslope of the main highlands of the country. The site served as a farmhouse during the Neo Assyrian rule and was dated to the second half of the 8th century BCE.Archaeological excavations of the site revealed a building that included two strips of rooms built around a square courtyard, a rock-hewn water reservoir, and agricultural facilities scattered in the area east and west of the building, including agricultural terraces.The main aim of the current research was to find an anthropogenic signature in the sediments of the site, and in the sediments of the surrounding fields. POSL, PXRF and XRF methods were applied in order to achieve this aim.The results showed that a significant anthropogenic signature was recorded on the sediments of the building and its square courtyard. This is reflected in the chemical composition that was enriched by phosphorus (P) and calcium (Ca), and by the mixed pOSL signal values. In the anthropogenic fields, the chemical signature is typical of natural soil with a high amount of Iron (Fe) and Manganese(Mn) which reflect high water availability.  It is interesting that although the site is small in size and was inhabited for a short period of time, the human imprint has remained hundreds of years after its abandonment.
Inferring near-surface NO2 concentrations for Belgium using multiple machine learning models and TROPOMI data
Authors: Sun Wenfu , Tack Frederik , Clarisse Lieven , Schneider Rochelle , Van Roozendael Michel
Published: February 2023

Near-surface nitrogen dioxide (NO2) is of great concern due to its impact on air quality and human health. Inferring the high-resolution spatiotemporal distribution of surface NO2 is necessary to assess the NO2 effects on human society and the ecosystem. Machine learning (ML) is an efficient approach to establishing a data-driven nonlinear mapping between targets and predictors. Various ML models have been used in past studies to estimate ground NO2 distributions from satellite observations (e.g., TROPOMI and OMI) and ancillary predictors (e.g., meteorology, land cover, and anthropogenic emissions) with good resolution, efficiency, and accuracy. In spite of these successes, the application of ML to infer near-surface NO2 remains challenging due to model stability issues and missing uncertainty estimations. In this research, we compare different ML models with respect to their predictive accuracy and spatiotemporal patterns. Moreover, we analyze the impact of the satellite remote sensing dataset and different predictors on model predictions using ML interpretation techniques. Based on these, we further investigate the possibility of assembling various ML models to provide a reliable ground NO2 estimation with uncertainty assessments. Overall, this study explores how ML models can be used to produce surface NO2 products, offering a perspective on practical applications for ML methods in atmospheric science.
Erosion through ancient geologic structures as a mechanism for freshwater fish speciation in a post-orogenic mountain range
Authors: Stokes Maya , Kim Daemin , Perron J. Taylor , Near Thomas
Published: February 2023

The legacy of tectonic deformation affects geomorphic and biological dynamics, even in post-orogenic mountain ranges. As ancient geologic structures originally created through tectonic deformation are exhumed through erosion, rocks with different chemical and physical properties are exposed at the surface of the landscape. We propose that this process not only influences landscape dynamics but is also a mechanism for speciation in freshwater fish.  As rivers erode through layers of different kinds of rock, the spatial distribution of rocks at the surface of the landscape changes. For fish with habitat specificity linked to rock type, erosion can progressively expose either favorable or unfavorable rock types, creating either barriers to or corridors for dispersal. The underlying structural geology will dictate which of those scenarios occurs. We present two case-studies that illustrate each scenario from the southeast United States, a freshwater biodiversity hotspot. First, we show that populations of the Greenfin Darter (Nothonotus chlorobranchius) are genetically isolated within tributaries flowing over the metamorphic rocks making up the thrust sheets of the Blue Ridge geologic province. In contrast, they are not found in rivers flowing over sedimentary rock of the Valley and Ridge. We show that over time, more sedimentary rock has been exposed, which has progressively isolated N. chlorobranchius populations from one another. In this case, river incision is introducing more barriers (sedimentary rock) into the landscape, leading to lineage diversification (i.e., speciation). In the second case-study, we explore the diversification of the Vermilion Darter complex that includes the federally endangered Vermilion Darter (Etheostoma chermocki) and the closely related Warrior Darter (E. bellator). Unique lineages of this species complex are restricted to tributaries flowing over carbonate rocks in the Black Warrior River. In contrast to the N. chlorobranchius case-study, here river incision is progressively expanding habitat by exposing more carbonate rock, driving dispersal-mediated allopatric speciation within the Vermilion Darter complex. Our results suggest that in bedrock-dominated rivers found throughout much of the Appalachian Mountains, erosion through ancient geologic structures can drive the diversification of freshwater fish, highlighting links between tectonic deformation, surface processes, and biological evolution in an ancient mountain range.
Intraspecific decline in shell size of the bivalve Harpax spinosus across the Pliensbachian/Toarcian transition
Authors: Tomašových Adam , Duarte Luís Vítor , Müller Tamas , Schlögl Ján
Published: February 2023

Abrupt changes in seawater temperature during the late Pliensbachian and early Toarcian significantly influenced not only species and functional diversity of marine benthic ecosystems, but also affected body size at intraspecific and community levels. Although community-level trends in body size driven by selectivity in species extinctions are well-documented, intraspecific trends in size and life-history strategies remain poorly explored. Harpax spinosus is an Early Jurassic plicatulid, bimineralic bivalve that was abundant during the Pliensbachian but went extinct at the onset of the Toarcian oceanic anoxic event. Here, we evaluate temporal changes in size-frequency distributions of this species at high stratigraphic resolution at Peniche and Fonte Coberta sections in the Lusitanian Basin. Analyses of H. spinosus at these sections document that this bivalve typically achieved 10-15 mm in length during the deposition of the margaritatus and spinatum zones, with left-skewed or bimodal size distributions. However, its median size significantly declines to < 10 mm within the spinatum Zone (in the upper part of the apyrenum Subzone), coinciding with the appearance of small koninckinid brachiopods. This size reduction is followed by a return to larger sizes in the upper part of the spinatum Zone. A second decline in size occurs in the lowermost Toarcian where Harpax co-occurs with small-sized Koninckella-Nannirhynchia assemblage (Koninckella fauna), immediately above the mirabile Subzone. Although this abrupt decline in size can be accentuated by condensation, the size distribution at bedding plane is strongly left-skewed (with infrequent small-sized individuals), in contrast to the size distribution in the overlying marl. Harpax assemblages in the lowermost Toarcian semicelatum Subzone are characterized by right-skewed or symmetric size-frequency distributions, with median size < 10 mm. Sclerochronological analyses of growth rings and stable isotopes indicate that the decline in size was not associated with any decline in lifespan and was rather associated with a decline in the von Bertalanffy growth coefficient.
Biomass recovery after fires dominates the carbon sink of boreal forests over the last three decades
Authors: Xu Yidi , Ciais Philippe , Li Wei , Saatchi Sassan , Santoro Maurizio , Cescatti Alessandro , Shchepashchenko Dmitry , He Guojin , Guido Ceccherini , He Jiaying , Fan Lei , Brandt Martin , Fensholt Rasmus , Wigneron Jean-Pierre , Kay Heather , Sitch Stephen , Bastos Ana , Bowing Simon , Ritter François , Fayad Ibrahim
Published: February 2023

Wildfires are an integral part of boreal forest dynamics. Understanding the carbon loss/recovery associated with fires is crucial to assess the stability of these slow-growing forests.  Yet, the carbon balance from fires and post-fire forest recovery remain uncertain at the biome scale due to the lack of spatial details about rates of forest regrowth. Here, we quantify carbon losses from fire emissions and gains from post-fire regrowth using high spatial-resolution satellite data and a bookkeeping model. We combined a 35-year long record of burned area from the Landsat satellites since 1985 with local biomass-age regrowth curves derived from high-resolution satellite-based above ground biomass (AGB) datasets. We found that forests in Eurasia tend to recover faster and reach higher biomass levels than those in North America. Young forests recovering from post-1985 wildfires produced a carbon sink of 652±200 TgC during the period 1985 to 2020. The additional recovery of older secondary forests that burned before 1985 further adds a cumulative sink of 1659±346 TgC. Comparatively, old-growth forests that did not burn accumulated 930±233 TgC during the period 1985-2020. This result shows 71% of the contemporary carbon sink in AGB is contributed by recovery from fires. After accounting for fire emissions each year and for the slow decay of coarse woody debris after burning, the net AGB carbon sink in boreal forests is 2108±234 TgC during 1985-2020. This study provides the first spatially explicit aboveground observation-based carbon budget of boreal forests and provides insights on the key factors that will control its future evolution.
High-resolution mapping of flood dynamics in cropland areas using multi-temporal Sentinel-1 SAR
Authors: Qiu Junliang , Tarolli Paolo
Published: February 2023

Flood hazards result in enormous casualties and huge food losses worldwide every year. Therefore, monitoring floods in flood-prone areas is crucial to better understand the flooding patterns and characteristics. Previous studies utilizing hydrological data were unsuccessful in identifying flooding patterns in the regions where the hydrological stations are sparse. In addition, studies based on optical satellite images did not successfully monitor floods in cloudy areas. To improve flood monitoring methods, Synthetic aperture radar (SAR) imaging was proposed to monitor floods. The Sentinel-1 SAR sensor, with a spatial resolution of 10 m and a swath of up to 400 km, has free access and a short revisit period. This study will use multi-temporal Sentinel-1 SAR data to monitor flood dynamics in large-scale flood-prone areas with a focus on croplands to identify the inundated duration of flooded croplands, which would be valuable to assess the flood damage on crops and flood impact on food security.
Which fault was it? - Late Pleistocene, glacially triggered earthquakes in NE Germany
Authors: Steffen Holger , Pisarska-Jamrozy Małgorzata , Belzyt Szymon , Börner Andreas , Hoffmann Gösta , Kenzler Michael , Rother Henrik , Steffen Rebekka
Published: February 2023

A sedimentological, geochronological, and geodynamic investigation of detailed micro- and meso-scale soft-sediment deformation structures (SSDS) within internally deformed layers on Gnitz Peninsula, Usedom Island, Germany, was performed in the last years. Five layers with SSDS were described of which four were possibly caused by glacial isostatic adjustment (GIA)-triggered earthquakes mirrored in liquefaction and reliquefaction phenomena (Pisarska-Jamroży et al., 2022). Hence, in line with earlier investigations and suggestions by Hoffmann and Reicherter (2012), the SSDS generation is related to oscillation of the Scandinavian Ice Sheet whose loading cycle caused stress changes likely releasing local earthquakes along pre-existing faults.Optically stimulated luminescence dating indicates a most probable time span of corresponding earthquake occurrence between 23.2 and 14.6 ka (including uncertainty). For the first time, glacially induced Coulomb failure stress changes were modelled for this area with a set of commonly accepted GIA models. They strongly support the interpretation of SSDS trapped in layers as seismites during that time. Using reliable fault parameters of faults in near vicinity of Gnitz Peninsula and suggested stress regimes and directions for northern Germany, the modelling can help indicate the most probable reactivated pre-Quaternary fault(s). If they can be confirmed after detailed palaeoseismological, geomorphological, geophysical, and structural investigations as so-called glacially induced fault(s), this would add another puzzle piece to a geodynamic scenario of glacially triggered faulting having affected an area from northern central Europe to northern Fennoscandia in the Late Pleistocene and Early Holocene.Our presentation will focus on the geodynamic setting of NE Germany, how it was changed during the last glaciation and how potentially reactivated faults can be determined.ReferencesHoffmann, G., Reicherter, K., 2012. Soft-sediment deformation of late Pleistocene sediments along the southwestern coast of the Baltic Sea (NE Germany). Int. J. Earth Sci. 101, 351-363, doi:10.1007/s00531-010-0633-z.Pisarska-Jamroży, M., Belzyt, S., Börner, A., Hoffmann, G., Kenzler, M., Rother, H., Steffen, R., Steffen, H., 2022. Late Pleistocene earthquakes imprinted on glaciolacustrine sediments at Gnitz Peninsula (Usedom Island, NE Germany). Quat. Sci. Rev. 296C, 107807, doi:10.1016/j.quascirev.2022.107807.
Seasonal and event-based dynamics of dissolved organic carbon (DOC) concentration in a Mediterranean headwater catchment
Authors: Senatore Alfonso , Corrente Giuseppina , Argento Eugenio , Castagna Jessica , Micieli Massimo , Mendicino Giuseppe , Beneduci Amerigo , Botter Gianluca
Published: February 2023

Hydrological factors are known to contribute to regulate the DOC balance at the reach scale. Interannual, intra-annual (seasonal) and event-based hydrological variability, particularly in headwater streams, affects stream-hillslope organic matter exchanges and river network connectivity, leading to significant space and time variations in sources and processes regulating DOC dynamics.This paper contributes to the ongoing effort to improve understanding of the related dynamics of streamflow and DOC concentration spatial variability across different timescales. Our investigation focused on a Mediterranean headwater catchment (Turbolo River, southern Italy) characterized by dry and hot summer climate enhancing network intermittency. The catchment was equipped with two multi-parameter sondes providing more than two-year (May 2019 to November 2021) continuous high-frequency measurements of several DOC-related parameters (fluorescent dissolved organic matter - fDOM, streamwater temperature and turbidity). The sondes were installed in two nested sections. The upstream sonde was located in a quasi-pristine sub-catchment, while the downstream sonde was placed at the Fitterizzi outlet, where some anthropogenic disturbances on water quality could be observed. Furthermore, streamflow data were acquired at both sites, while weather parameters were monitored at the catchment outlet. DOC estimates were achieved by correcting the fDOM values through an original procedure that did not require extensive laboratory measurements. Then, DOC dynamics at the seasonal and storm event scales were analyzed for both sites.At the seasonal scale, results confirmed the climate control on DOC production, with background concentrations that increased in hot and dry summer months. The hydrological regulation proved crucial for DOC mobilization and export, with the top 10th percentile of discharge being associated with up to 79% of the total DOC yield. The analysis at the storm scale examined 19 events per site using flushing and hysteresis indices. Our results highlighted substantial differences between the two catchments. In the steeper upstream catchment, the limited capability of preserving hydraulic connection in time with DOC sources determined the prevalence of transport as the limiting factor to DOC export. Downstream, transport- and source-limited processes were observed almost equally. The correlation between the hysteretic behaviour and antecedent precipitation was not linear since the process turned to be transport-limited for high accumulated rainfall values. Overall, the study demonstrated the importance of high-resolution measurements to explain DOC dynamics at multiple time scales with a quantitative approach.
Understanding the Sources of Climate Uncertainty in Projections of Climate Impacts
Authors: Schwarzwald Kevin , Lenssen Nathan
Published: February 2023

Uncertainty in climate projections is driven by three components: scenario uncertainty, inter-model uncertainty, and internal variability. Although econometric climate impact studies increasingly take into account the first two components, little attention has been paid to the contribution of internal variability. Policymakers generally respond to short-term challenges on time horizons of days to decades, when internal variability is largest in projections of climate variables. Underestimating this uncertainty due to internal variability can lead to underestimating the socioeconomic costs of climate change and therefore estimates of the social cost of greenhouse gases. Using large ensembles from seven Coupled General Circulation Models with a total of 414 model runs, we partition the climate uncertainty in classic empirical dose-response models relating county-level corn yield, mortality, and per-capita GDP to temperature in the continental United States. Internal variability represents more than 50\% of the total climate uncertainty in certain projections, including mortality projections for the early 21st century, though its relative influence decreases for projections farther in the future. These findings suggest that uncertainty due to internal variability must be included for accurate uncertainty quantification in projections of temperature-driven impacts including early- and mid- 21st century projections, projections in regions with high internal variability such as the Upper Midwest United States, and for impacts driven by non-linear relationships. We conclude with recommendations on how to account for differing sources of climate uncertainty when constructing projections of the socioeconomic impacts of climate change impact.
Exploring Real-time Oxygen Dynamics in the Rhizosphere of Sorghum with High Spatial and Temporal Resolution
Authors: Shorter Joanne , Roscioli Joseph R. , Lunny Elizabeth , Eddy William , Yang Wendy
Published: February 2023

The presence of oxygen in soil controls the occurrence and rates of biogeochemical processes underlying soil nutrient transformations and greenhouse gas dynamics.  Oxygen (O2) levels within the rhizosphere are heavily modulated by both root and microbial respiration.  Thus, a microscopic environment near the root may be a microbial hotspot and not well represented by broader, non-rhizosphere soil.  Here we examine the millimeter-scale oxygen consumption or loss processes in the rhizosphere of sorghum, how they are influenced by irrigation practices, and the relationship between oxygen dynamics and nitrification in the rhizosphere.In a field study at a research farm at the University of Illinois Urbana-Champaign, sorghum was grown under a rainout shelter with plants undergoing one of 2 irrigation treatments.  Soil O2 concentration and isotopic ratios, nitrous oxide (N2O), and carbon dioxide (CO2) were measured in the rhizosphere of the sorghum via an array of novel microvolume probes coupled to an Aerodyne TILDAS (Tunable Infrared Laser Direct Absorption Spectrometer).  Probes were placed within the rhizosphere or outside the root zone with the aid of root windows installed at the site.We collected continuous, real-time, in situ measurements of O2, O2 isotopes, CO2 and N2O over the 2022 sorghum growing season.  The high spatial and temporal resolution of the measurements allowed us to observe spatiotemporal heterogeneity of biogeochemical activity in the rhizosphere as a function of agricultural activity.  We will also report on controlled laboratory incubations to quantify the impact of soil microbial oxygen consumption on 18O enrichment as compared to water displacement in the soil; and controlled greenhouse experiments to measure fine scale gradients of oxygen concentrations and isotopic composition near roots.The novel microvolume sampling system coupled with the O2 detection method can provide insights into fine scale gradients driven by higher microbial activity in microbial hotspots within the rhizosphere.  Measurements on this mm-scale have further applications for monitoring other trace soil gases and their spatial and temporal heterogeneity in soil systems. 
A synthesis of the use of citizen science on soils and agroecosystems across Europe
Authors: Gascuel-Odoux Chantal , Aldrian Ulrike , Goetzinger Sophia , Masson Eloise , Miloczki Julia , Sandén Taru
Published: February 2023

Along with the development of citizen science, more and more citizen science initiatives on soils are emerging. Soils are key components of ecosystems and from where 95% of our food originates. Because soils integrate multiple impacts of human activities, they are increasingly taken into account in public policies (agroecology, biodiversity, food, climate). This presentation will share the results of an online survey on agricultural soil citizen science across Europe. Most reported citizen science projects were at the national level (56%, n=40), limited in time (64.9%, n=40) because of funding (82.6%, n=23), with a budget less than 50.000 € (41.7%, n=36) and funded by a national research funding agency (47.2%, n=36). Regarding agricultural soil systems, half of citizen science projects studied urban or urban-countering gardening and 39% studied cropping systems, 29% fruit-vegetables and grassland systems, 18% arboriculture and vineyards. Over 57% of the reported projects have generated soil biodiversity data, 46% and 35% vegetation cover and soil organic carbon data, respectively. According to citizen science coordinators (n=33), the benefits for the scientists taking part in citizen science were ranging from publication of research outputs (69.7%) and learning opportunities (63.6%) to the potential to influence policy (45.5%). The reported benefits for the citizen scientists (n=33) ranged from learning opportunities (81.8%) and satisfaction through contributing to scientific evidence (72.7%) to publication of research outputs (24.2%). ‘Project very time consuming’ and ‘funding temporary’ were identified as the main research challenges for citizen science projects (n=31). ‘More staff resources’ was reported as the most important prerequisites for citizen science work followed by ‘more financial resources’ and ‘more recognition from academia for citizen science’ (n=28). This synthesis shows the state of the art in agricultural soil citizen science, but also the main lockers for citizen science development on soils.
Reconstructing the localized transient high stress state of seismogenic faults in the lower crust, Lofoten, Norway
Authors: van Schrojenstein Lantman Hugo , Menegon Luca
Published: February 2023

Pseudotachylytes (frictional melts produced during seismic slip) in the metamorphosed anorthosites of the Lofoten archipelago preserve a record of seismic rupture in the dry lower crust at 650–750 °C, 0.8 GPa. Pyroxene deformation microstructures associated with preseismic loading and coseismic fragmentation reveal strongly localized transient stresses that presumably reached GPa-level magnitude. However, such transient high stresses have never been measured in exhumed seismogenic faults. In this work, we use high-angular resolution electron backscatter diffraction (HR-EBSD) on pyroxene grains to obtain spatial datasets of residual stresses retained in the crystal lattice. With these data, we aim to reconstruct the progressive build-up and release of transient high stress as it is recorded in the pyroxenes, and whether this recorded stress is related to preseismic loading or coseismic fragmentation.The analysed anorthosite wall rock of a pseudotachylyte at the Nusfjord locality consists mostly of plagioclase, diopside, and enstatite, with diopside forming the main target minerals of this study. HR-EBSD maps were obtained in the wall rock at various distances from the pseudotachylyte interface along a 10 mm long transect, and on survivor clasts within the pseudotachylyte.EBSD reveals that most diopside in the wall rock contains micron-scale deformation twins, except within 50 microns of the pseudotachylyte where it is fragmented. Residual stresses obtained via HR-EBSD vary along the transect, and are generally lower at greater distance from the pseudotachylyte. The highest values approximately coincide with the lithostatic pressure. The residual stresses are not in agreement with the very high transient stresses (>1 GPa) expected during the rupture propagation. Rather, the analysed diopside recorded the progressive build-up of stress during preseismic loading.
Internet of Things Lab for Air Quality Monitoring
Authors: Tchanche Bertrand , Fall Ibrahima
Published: February 2023

Anthropogenic activities emit particulate matter (PM) and gaseous substances that are harmful. PM has adverse effects on different parts of the body. Atmospheric pollution is a global threat with an increasing social and economic costs. Poor air quality is a concern in African cities, but governments have been too slow to react, one of the reasons being the scarcity of data on different air pollutants. Instruments based on low-cost sensors and Internet of Things are being considered as solution to evaluate the concentration of different pollutants. Increasing number of manufacturers are proposing sensing devices with good accuracy. Low-cost sensors are an alternative to expensive high graded equipment. They are cheap and can be easily deployed. Here we present the IoT4AQ project. It is funded by the International Astronomical Union (IAU). The main objective is to organize training sessions for researchers and students on the design and implementation of low-cost sensors for air quality monitoring. The project will use astronomy instrumentation knowledge and skills. Participants will be trained in IoT techniques showing how to build low-cost sensors-based instruments and deploy them. The project starts on February 2023, will last for two years and trainers will be invited on various aspects of the trainings. Two hands-on trainings and two online seminars will be organized each year. The project will be implemented in Senegal and the first year will see the participation of local trainees and in the second phase it will open to participants from other African countries. Specific objectives are: (1) organize hands-on trainings and online seminars on IoT and air quality monitoring, (2) train researchers, teachers, and students on various aspects of air quality monitoring and (3) improve Physics education in Africa through low-cost sensors and IoT. Expected outcome are as follows: (1) train a minimum of 100 participants on IoT and air quality monitoring; (2) improve the experimental skills of participants; and (3) increase awareness of the threat that represents atmospheric pollution.
In-vehicle exposure to NO2 and PM2.5: influences of environmental, vehicle and driving factors
Authors: Matthaios Vasileios , Harrison Roy , Koutrakis Petros , Bloss William
Published: February 2023

In many developed cities, commuters spend more than 1.5-h inside vehicles daily, which may result in elevated exposures to traffic-related NO2 and PM2.5, which are known to have harmful health effects. In addition, time spend inside vehicles is likely to be greater for professional drivers, whereas the impacts of these exposures may be greater for vulnerable groups such as the elderly or obese. Therefore, reducing in-vehicle exposure and the associated risk for adverse health effects is very important.This study measured in-vehicle NO2 and PM2.5 during repeated transects of the same route on city streets for 10 vehicles under real-world conditions, and as a function of ventilation settings and cabin filters. The results were used to assess personal exposure for driver/passengers, and to develop stepwise general additive models in order to identify important controllable factors that can reduce in-vehicle exposure.The overall variability of in-vehicle exposure explained by these models was R2 = 0.58 and 0.52, for NO2 and PM2.5 respectively. From the model’s explained variability, the most significant predictor for both pollutants was on-road NO2 and PM2.5 levels accounting for 25.4 and 35.6% respectively. Vehicle-based predictors included car type, odometer, use of activated carbon filter, air exchange rate and use of air conditioning/air recirculation ventilation settings that, in combination, explained 48.9% and 61.1%, of NO2 and PM2.5, variability, respectively. Driving-based predictors included road traffic conditions, presence of traffic lights roundabouts and high emitters, explained 25.7% and 3.3% of NO2 and PM2.5 in-vehicle concentration variability, respectively. By carefully regulating vehicle-based factors under driver or passenger control, such as ventilation and filtration options, vehicle occupants can significantly reduce their exposure to NO2 and PM2.5.
Estimating intermittency significance by means of surrogate data: implications for stationarity
Authors: Teodorescu Eliza , Echim Marius , Johnson Jay , Munteanu Costel
Published: February 2023

Intermittency is a property of turbulent astrophysical plasmas, such as the solar wind, that implies non-uniformity in the transfer rate of energy carried by non-linear structures from large to small scales. We evaluate the intermittency level of the turbulent magnetic field measured by the Parker Solar Probe in the slow solar wind in the proximity of the Sun, at about 0.17 AU, during the probe’s first encounter. A quantitative measure of the intermittency of a time-series can be deduced based on the normalized forth order moment of the probability distribution functions, the flatness parameter. We observe that when dividing the data into contiguous samples of various lengths, from three to twenty-four hours, flatness differs significantly from sample to sample, suggestive of alternating intermittency-free time intervals with highly intermittent samples. In order to describe this variability, we apply an elaborate statistical test tailored to identify nonlinear dynamics in a time series which involves the construction of surrogate data that eliminate all nonlinear correlations contained in the dynamics of the signal but are otherwise consistent with an “underlying” linear process, i.e. the null hypothesis that we want to falsify. If a discriminating statistic for the original signal, such as the flatness parameter, is found to be significantly different than that of the ensemble of surrogates, then the null hypothesis is not valid, and we can conclude that the computed flatness reliably reflects the intermittency level of the underlying non-linear processes. We determine that non-stationarity of the time-series strongly influences the flatness of both the data and surrogates and the null hypothesis cannot be falsified. The intermittency level detected in such cases reflects the effects of isolated and, maybe, statistically not meaningful events, consequently, we stress upon the importance of careful data selection and evaluating the significance of the evaluated discriminating statistic.
Decadal scale influence of rainfall induced landslides on fluvial sediment transport following typhoon Morakot
Authors: Ruetenik Gregory , Ferrier Ken , Marc Odin
Published: February 2023

Landslides are of wide interest because they shape topography and influence fluvial sediment transport. To investigate the duration of landsliding's influence on fluvial sediment discharge, we analyzed suspended sediment concentration measurements at 77 gauging stations across Taiwan over an 11-year period after Typhoon Morakot in 2009, the wettest typhoon on record in Taiwan which generated nearly 20,000 landslides. At each gauging station, we computed annual rating curves for suspended sediment concentration as a power-law function of the centered water discharge, which isolates the efficiency of suspended sediment discharge from temporal variations in water discharge. Among the 40 stations in basins that were strongly impacted by landsliding, the discharge-normalized rating curve coefficient ã increased by a mean factor of 4.89 within 1-2 years of Morakot, while the rating curve exponent b exhibited no systematic response to Morakot (mean factor of 1.21). Elevated values of ã declined exponentially at 26 of the 40 stations with a median characteristic timescale of 13.2 years (interquartile range: 7.6-20.7) and tended to respond faster in basins with more intense landsliding. In contrast, at the 37 stations that were not impacted by landsliding, neither ã nor b exhibited a systematic response to Morakot. To quantify the effect of landsliding on sediment discharge, we compared the measured sediment discharges after Morakot to the hypothetical sediment discharges that would have occurred if no change in sediment transport efficiency had occurred at the time of Morakot, calculated by applying the post-Morakot water discharge history to pre-Morakot rating curves. This analysis suggests that Morakot-induced landsliding increased sediment discharge by as much as >10-fold in some basins in southeast Taiwan in the 1-2 years after Morakot. Post-Morakot changes in ã were positively correlated with landslide intensity for approximately seven years after Morakot, and changes in b were negatively correlated from 2011 to 2014, indicating that the influence of landsliding on rating curves diminished within a few years. Together, these results suggest that Morakot-induced landsliding amplified fluvial sediment fluxes for a relatively short time (< 10 years). To the extent that these results are applicable to rivers in other landscapes, this suggests that rivers may more efficiently transport landslide-derived sediment for relatively short times.
Cross-shelf exchanges between the East Greenland shelf and interior seas
Authors: Duyck Elodie , De Jong Femke
Published: February 2023

The Atlantic Meridional Overturning Circulation (AMOC) is predicted to weaken in the 21st century as a result of climate change. One of the proposed drivers for such a weakening is the dampening of deep convection in the Subpolar North Atlantic following an increase in freshwater fluxes from the Greenland ice sheet. However, the fresh waters that flow from Greenland and the Arctic to the Subpolar North Atlantic are primarily found over the Greenland shelf, and it is unclear where and how much freshwater is exported from the shelf to the interior seas where deep convection occurs. While the main export of freshwater off the Greenland shelf is likely to occur west of Greenland, the importance of water mass transformation and overturning east of Greenland in the total subpolar AMOC makes it essential to better understand freshwater exchanges between the east Greenland shelf and deep convection regions of the Irminger and Nordic Sea.We investigate these exchanges using drifter data from five deployments carried out at different latitudes along the east Greenland shelf in 2019, 2020 and 2021, as well as satellite data and an atmospheric reanalysis. We compute Ekman transport (from winds) and geostrophic velocity (from satellite altimetry) at the shelfbreak and find that the Blosseville Basin, just upstream of Denmark Strait, and Cape Farewell, are particularly favorable to cross-shelf exchanges. We further investigate exchange processes in these regions using drifter data. In the Blosseville Basin, drifters are brought off-shelf towards the Iceland Sea and into the interior of the Basin, possibly joining the separated EGC. As they flow downstream, they re-enter the shelf and most are driven towards the coast. This exchange appears to be mainly driven by the shape of the bathymetry. At Cape Farewell, the wind appears to be the main driver, although occasionally an eddy seems to turn drifters away from the shelf. The drifters brought off-shelf at Cape Farewell mostly continue around Eirik Ridge, where they re-enter the West Greenland Current. How much of the freshwater signature is lost between leaving the East Greenland Current and entering the West Greenland Current is not clear and will need further study.
Assessment of precipitation statistics with non-hydrostatic regional climate model RegCM4.7.1 at regional and convection-permitting scale over Bulgaria
Authors: Valcheva Rilka , Popov Ivan , Gerganov Nikola
Published: February 2023

The aim of this study is to present an assessment of precipitation, simulated with the non-hydrostatic regional climate model RegCM4.7.1 at a regional and convection-permitting (CP) scale for a decade-long period, over Bulgaria domain. The simulations use a horizontal grid spacing of 3 km and are driven by the ERA-Interim reanalysis (0.75° x 0.75°) through an intermediate driving RegCM4 simulation at 15 km grid spacing using parameterized deep convection. The km-scale simulation is evaluated against E-OBS (0.1° x 0.1°) and CHIRPS (0.05° x 0.05°) datasets and is compared with the coarser-resolution driving simulation. We focus on different precipitation statistics such as seasonal mean daily precipitation, seasonal wet-day intensity, seasonal wet-day frequency, and seasonal heavy precipitation. The simulated period is 2000 - 2010.  The simulations are carried out on the HPC Discoverer supercomputer, located in Sofia Tech Park in Sofia, Bulgaria.     Acknowledgements    This work is supported by the Bulgarian National Science Fund, KP-06-М57/3. We acknowledge Discoverer PetaSC and EuroHPC JU for awarding this project access to Discoverer supercomputer resources.   Keywords: RegCM4.7.1; km-scale resolution; convection-permitting; extreme precipitation; intensity; frequency; regional climate modelling; Bulgaria
Looking for permafrost signatures in Arctic streams: the case of meandering rivers
Authors: Ragno Niccolò , Crivellaro Marta , Bonanomi Riccardo , Zolezzi Guido , Tubino Marco , Lamb Michael
Published: February 2023

Meandering is one of the most common morphological pattern through which rivers manifest themselves. Here, the attention is devoted to meandering streams carving their path through permafrost floodplains, which typically characterize cold environments such as the Arctic. Despite meandering rivers have been widely studied in the last fifty years, little is known about the dynamics of streams where banks are composed of perennially frozen material. It is inquired whether there is a morphological signature in the planform of permafrost streams potentially deriving from specific thermo-mechanical processes occurring in Arctic landscapes, like the formation of thermo-erosional niches and sediment slumps caused by thaw-weakened soil. To this aim, a bend scale analysis of the planform geometry of several Arctic streams by means of Landsat satellite imagery is employed. Morphodynamic features such as lateral migration rates, channel curvatures, and width variations, are extracted from multispectral remotely sensed data by combining Google Earth Engine (GEE) with an established process-based software (PyRIS).  Following a methodology based on continuous wavelet transform, a set of metrics quantitatively defining the meander shape, which include fattening and skewing coefficients, are used to compare permafrost streams with a series of natural meandering rivers from tropical and temperate regions obtained from the literature. The present analysis opens the way to a systematic integration between remote sensing and physically-based morphodynamic models able to incorporate thermo-mechanical processes uniquely related to permafrost environments.