bluuebunny/crossref_metadata_2025 huggingface dataset:
Adequacy and Reliability of Earth System Models: Actionable Purposes, Model Inadequacy and Epistemic Risk
Authors: Morrison Monica
Published: February 2023

For scientific products to be considered actionable for stakeholder purposes they must meet certain epistemic and contextual conditions of adequacy. In evaluating the adequacy of a scientific product derived from Earth system models for actionable purposes—such as adaptation or resilience planning— there is a tendency to engage in the evaluation of raw model output and subject it to postprocessing to gain desired reliability and fitness. However, this reductive approach and focus on data ignores questions of whether the simulations, model configurations, and representational features of the models are themselves adequate and reliable for the actionable applications. This talk will lay out the reasons why we need to shift our practices to evaluating models and their products in a more holistic manner and provides insight into a framework for doing so. Scientific models—in this case Earth system models—are constructed with certain purposes and research questions in mind. These purposes, and more detailed research questions, engender representational values, which are reflections of what we want to know and why we want to know it. When model development is informed by these representational values underlying our questions and purposes, they are determinants of the decisions made during model construction about what we choose to represent and how we choose to represent it. The consequence is that the models constructed reflect these representational values and occupy a representational perspective, one that is fit for answering the questions and purposes that governed its development, but not those questions and applications that lie outside that perspective. To avoid increasing epistemic risk when using models for actionable purposes, which can result in downstream social harms, we need to assess the adequacy and reliability of our instruments and their products further upstream, in terms of consistency between the representational values that are embedded in the model in virtue of its development pathway and those that are implied in the actionable science questions the model could be applied to answer. More holistic, tailored assessments will allow us to avoid increases in epistemic risk due to how stakeholder representational values and conditions of adequacy can be inconsistent with those values being reflected in the representational content of the model being employed.
Participatory Bayesian Network modelling to assess climate change risks and adaptation regarding water supply: integrating multi-model ensemble hazard information and local expert knowledge
Authors: Kneier Fabian , Woltersdorf Laura , Döll Petra
Published: February 2023

Local climate change risk assessments and climate resilient adaptation are best supported by a quantitative integration of physical hazards, exposures and vulnerabilities that includes the characterization of uncertainties. However, it is challenging to take into account the complex information of climate change projections and uncertainties in participatory risk assessments with decision-makers. We propose to use Bayesian Networks (BNs) for this task. Bayesian Networks are a cutting-edge integrated modelling approach for combining qualitative and quantitative knowledge in uncertain and complex domains, such as climate change impacts on water. To quantify potential future hazards of climate change on water, it is state-of-the-art to rely on multi-model ensembles to integrate the uncertainties of both climate and impact modelling. At the same time, local expert knowledge needs to be integrated in local climate change risk assessments. We show how to integrate freely-available output of multiple global hydrological models into BNs, in order to probabilistically assess risks for water supply. To this end, a roadmap to set up BNs and apply probability distributions of risk levels under historic and future climate and water use in a participatory manner was co-developed with water experts from Spain and the Maghreb. Multi-model information on hydrological variables was computed by three global hydrological models driven by the output of four global climate models for four greenhouse gas emissions scenarios. The output of projected relative changes of hydrological hazards was pre-processed using MATLAB, taking into account local information on water availability and use, to set up the BN. Results show that the method is useful for probabilistically computing climate change impacts on water stress and to assess potential adaptation measures in a participative process with stakeholders and decision-makers. Local water experts positively evaluated the BN application for local climate change risk assessments. While requiring certain training, the presented approach is suitable for application in the many local risk assessments necessary to deliver efficient and successful climate resilient adaptation.
An alternative approach to sediment source identification: uncertainty analysis and sample number optimization
Authors: Buligon Lidiane , Buriol Tiago , Minella Jean
Published: February 2023

Identifying sediments sources is an important branch of catchment erosion modeling that uses multiple tracers in a robust set of statistical analysis techniques commonly known as the “fingerprinting approach”. The techniques employed in the fingerprinting approach follow two distinct stages of multivariate statistical analysis: discrimination and classification. The first one refers to determining the best set of tracers that have the potential to be selected as a tracer. The second stage consists of classifying the eroded sediment samples in the n-dimensional space defined by the tracer properties. In this step, the relative contribution of each source to the composition of the suspended sediment is calculated. One of the challenges for improving the “fingerprinting approach” is estimating the uncertainties of the results. In this sense, defining the number of samples used to characterize sources and eroded sediments is considered an important issue in terms of costs and source of uncertainties. Therefore, the main objective of this work is to present an alternative modeling with a focus on uncertainty analysis and sample number optimization based on the model developed by Clarke and Minella (2016). The advantages of the proposed model include 1) the calculus of the source apportionments, making it possible to evaluate the effects of reducing the sample number on the uncertainties; 2) takes account the collinearity between the tracers adding the variance-covariance matrix applied into the generalized least squares (GLS) method; and 3)  adds the calculus of uncertainty associated with the number of samples (sediment sources and the  sediments. To demonstrate the usefulness of the model, we used a dataset available from the Arvorezinha experimental catchment located in southern Brazil. The implementation of this model was carried out in the Phyton®, so that any user can evaluate the uncertainties in the reduction of the number of samples as well as the importance of collinearity in the set of available tracers. The results confirmed the assumption the increased uncertainty as the number of samples decreases in the sources or eroded sediment samples. Moreover, the addition of the variance-covariance matrix in the solution of the overdetermined system allows to take into account the deleterious effects of collinearity in the fingerprinting approach. With this tool, new perspectives are opened to systematically improve the definition of the number of samples needed based on the uncertainty analysis of the set of samples available, fundamental to the advancement of research in the area of environmental monitoring and modeling, as well as for the management of water resources and soil management in agricultural catchments.
Tracing Longitudinal Patterns of Subsurface Hillslope-Stream Connections Across Catchments
Authors: Gariremo Natasha , Hopp Luisa , Blume Theresa
Published: February 2023

Subsurface stormflow (SSF) generated on hillslopes is an important hydrological process in headwater catchments. Tracing SSF flow paths and ultimately quantifying its contribution to streamflow is challenging as the signal can undergo various transformations from the hillslope. The riparian zone specifically, can act as a mixing and storage zone and may change strongly the physical and chemical signals of hillslope SSF before it reaches the stream. As a consequence, SSF may not be recognized as streamflow contribution. Thus, the relevance of this process for streamflow generation is currently not fully understood. In addition, studies often focus on quantifying SSF generation at the hillslope scale. Therefore, there is a lack of data to fully understand SSF characteristics at the catchment scale.The aim of this study is to characterize the hillslope-stream connectivity at the reach to catchment scale, using physical as well as chemical information. To deal with the challenges associated with measuring the SSF signal, this study implements a novel multi-method experimental design that will create a unique along-stream data set of hillslope contributions to streamflow in four test catchments in Germany and Austria. A combination of extensive salt dilution gauging along streams, water level measurements in-stream and in near-stream groundwater, longitudinal Radon profiles in streamwater and regular sampling of near-stream groundwater and streamwater for hydrochemical analyses will allow to evaluate the spatial variability of SSF inputs to the stream and to quantify the along-stream attenuation of the SSF signal.Here, we present the study outline as well as first data of water chemistry in near-stream groundwater and streamwater and will characterize the longitudinal patterns of a range of hydrochemical tracers along the streams in the four test catchments. The data set we will collect will be used to simplify and minimize future experimental effort and to identify simple proxies for regionalization. Ultimately, we aim to develop a framework to determine the likelihood of hillslope-stream connectivity at the catchment scale, as influenced by landscape and climate characteristics.
Low vs. upland - copper addition regulates denitrification in cropland soils from N2O emissions hotspots in Denmark
Authors: Liu Yujia , Poultney Daniel Mika-Nsimbi , Wichern Florian , Ambus Per , Müller Carsten W.
Published: February 2023

Agricultural land-use makes up around 38% of the total global land surface. Farming activities are a major source of greenhouse gas emissions (carbon dioxide, methane and nitrous oxide) worldwide. Nitrous oxide (N2O) emissions from agricultural land are an important contributor to the overall greenhouse gas budget. The high spatial and temporal variation of N2O emissions in agricultural lands makes it more challenging and important to quantify the actual emissions. Denmark’s glacial landscape is characterized by a high abundance of topographic depressions. These are typically flooded for 1-3 months per year, mainly during late winter and spring season. As these depressions are frequent in agricultural areas, their soils are exposed to an increased nitrate availability due to regular fertilization. The combination of high-water saturation and high nitrate availability results in distinct landscape denitrification and thus N2O emission “hotspots”.The reduction of N2O to N2 by N2O reductase can be an important mechanism to mitigate N2O emissions. The N2O reductase is both Cu and pH sensitive. Studies have showed Cu-modified organic fertilizer have the potential to enhance the reduction from N2O to N2, and therefore decrease N2O emissions from fields.In this study, we aimed to elucidate if Cu addition alters the emission of N2O from upland and depression soils in a different way. Therefore, we conducted an incubation experiment with both upland and depression soils, testing how different levels of Cu addition and two different water levels affect the emission of N2O. In order to differentiate the N2O production pathways (nitrification or denitrification), we applied 15N tracer in the form of 15NH415NO3 or 14NH415NO3. We also added 13C labelled maize residues to be able to trace the consumption of fresh substrate in the course of denitrification as affected by different Cu and water levels.Interestingly, although the soils were homogenized and incubated at the same water availability, we demonstrated a clearly higher N2O emission from the depression soils compared to the upland soils. In general, we were able to demonstrate that Cu addition clearly reduces the level of N2O emissions from upland soils, which is clearly more pronounced at higher soil water levels.
On the Contribution of Coronal Mass Ejections to the Heliospheric Magnetic Flux Budget on Different Time Scales
Authors: Winslow Reka , Scolini Camilla , Lugaz Noé , Schwadron Nathan , Galvin Antoinette
Published: February 2023

Coronal mass ejections (CMEs) contribute closed magnetic flux to the heliosphere while they are connected at both ends to the Sun and play a key role in adding magnetic flux to the heliosphere. Here, we discuss an outstanding question in heliophysics: how the type of magnetic reconnection that opens CME field lines in the inner heliosphere, i.e. interchange (IC) reconnection (below the Alfvén surface) and/or interplanetary (IP) reconnection (above the Alfvén surface), determines the length of time CMEs contribute to the heliospheric flux budget. Although IP reconnection does not alter the total amount of magnetic flux in the heliosphere, it matters in this context because it prevents the efficient opening of CME closed magnetic flux through IC reconnection, thereby prolonging the length of time that CMEs contribute closed magnetic flux to the heliosphere. We suggest that there is a varying timescale of contribution of individual CMEs to the heliospheric flux budget, with some CMEs contributing for considerably longer than others, depending on their interactions in IP space (i.e., depending on the fraction of the CME magnetic field lines opened up through IP reconnection vs. IC reconnection, or both). Such a distinction has not been taken into account in past studies that estimate the CME flux opening timescale. We outline key criteria to aid in distinguishing IC reconnection from IP reconnection based on in situ spacecraft data and highlight these through two example events. Studying the manner in which CMEs reconnect and open in the inner heliosphere has implications for a broad range of solar and heliospheric physics research areas and yields important insights not only into CMEs' role in the heliospheric flux budget but also the evolution of CME complexity, connectivity, and topology.
Ground and space data products provided by GFZ to the ESA Space Weather Service Network
Authors: Kervalishvili Guram , Rauberg Jan , Matzka Jürgen , Korte Monika
Published: February 2023

The Space Weather (SWE) Service Network of the European Space Agency’s (ESA’s) Space Safety Programme provides timely and reliable space weather information to end users allowing the mitigation and prevention of the impact of hazards from space on the communication and navigation systems, power grids, and aviation, etc. The SWE Service Network consists of 5 Expert Service Centres (ESCs), Solar Weather, Space Radiation, Ionospheric Weather, Geomagnetic Conditions, and Heliospheric Weather, which are distributed and established across Europe providing coverage of space weather phenomena and impacts on ground and space-based infrastructure. Note that a free registration at the ESA's SWE portal is necessary to get access to the protected applications or products.Here, we give an overview of 18 products that currently are provided by GFZ in the Ionospheric Weather ESC (I-ESC) and Geomagnetic Conditions ESC (G-ESC). These products are derived from the Low Earth Orbiting (LEO) satellite and ground-based observations. In I-ESC, the following Swarm mission products are provided: Rate Of the change of TEC (ROT), Total Electron Content (TEC), in-situ electron density (Ne), Ionospheric Bubble Index (IBI), Rate Of the change of TEC Index (ROTI). And in G-ESC: the location and intensity level of the Polar Electrojet (PEJ), Field-Aligned Currents (FACs), and Vector Magnetic Field (MAG) components. The following global geomagnetic indices are provided in G-ESC, nowcast Kp (three-hourly), Hp60 (one-hourly and open-ended), Hp30 (half-hourly and open-ended) indices, most recent definitive Kp index, Kp, Ap, Hp60, ap60, Hp30, ap30 indices on tabular form, Kp and Ap (since 1932), Hp60, ap60, Hp30 and ap30 (since 1995) indices archive.
Vegetation losses due to surface ozone concentrations from fires in Portugal mainland
Authors: Alonso Catarina , Gouveia Célia
Published: February 2023

Tropospheric ozone (O3) is an important anthropogenic gas, and it is a secondary air pollutant. The combination of sunlight with non-methane hydrocarbons (NMHCs) and NOx (NO + NO2) from biomass burning results in significant photochemical production of O3. Since the fire season in Portugal occurs during the summer, these emitted O3 precursors lead to the production of O3. An excessive concentration of tropospheric O3 damage leaves, decreasing photosynthesis, plant growth and biomass accumulation and costing, therefore, billions of dollars annually in lost plant productivity.The main objective of this work is to understand if there is a relationship between the loss in crop yields due to the concentration of O3 derived from fires, in Portugal mainland. Therefore, this work is divided into three phases: i) to evaluate the relationship between tropospheric O3 and extreme fires; ii) relate the contribution of O3 to vegetation productivity contraction; and iii) relate the fire-induced O3 increments to vegetation losses. To access to tropospheric O3 concentration data Atmospheric Infrared Sounder (AIRS) and Copernicus Atmosphere Monitoring Service (CAMS) products were used. The AIRS Version 7 Level 3 product are daily, gridded mean geophysical parameters on 1°x1° grid cells, with higher internal vertical resolution at 100 pressure levels (1000 hPa – 1 hPa). The CAMS reanalysis (CAMSRA) O3 data have a temporal resolution of 3 h and a spatial resolution of approximately 80 km (0.7°x0.7° grid cells) with 60 hybrid sigma–pressure (model) levels (13 levels, 400 - 100 hPa) in the vertical (top level at 0.1 hPa).  Vegetation productivity is assessed by means of Gross Primary Production (GPP) available from Moderate Resolution Imaging Spectroradiometer (MODIS) collections. It can be concluded that when fires occur in large areas, such as the fires of 2012 (Serra do Caldeirão) and 2018 (Monchique) the levels of surface O3 concentration have a high increase, which can lead to a decrease in vegetation and crop productivity.Acknowledgements: This study is partially supported by the European Union’s Horizon 2020 research project FirEUrisk (Grant Agreement no. 101003890) and by the Portuguese Fundação para a Ciência e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC) – UIDB/50019/2020- IDL,  DHEFEUS - 2022.09185.PTDC
Monitoring the environmental conditions in landfill sites: a case study of Fyli - Ano Liosia, Attica Region, Greece
Authors: Efstathiou Eirini , Karathanassi Vassilia
Published: February 2023

Landfills constitute a major environmental issue that needs to be handled, especially when they are located near large urban areas. In landfills, end up most of the city non-hazardous solid waste (mainly household waste), which are not appropriate for recovery/recycling and thus they are disposed in the ground for decomposition process. Monitoring of such sites is significantly important, due to the fact that the decomposition process - which includes the release of hot gases - is harmful to the environment and to the human health.  The increase of Land Surface Temperature (LST) in landfill sites and the methane gas emissions, which contribute to the greenhouse effect, can be monitored using remote sensing methods and techniques. This type of monitoring is very important for safeguarding the surrounding environment, especially in environmentally sensitive areas, as are those located close to densely populated areas, and therefore, many studies have been carried out focusing on the monitoring of the environmental impacts of landfills through remote sensing. In relevance with previous literature, the current study aims at monitoring the environmental impact of the active landfill site of Fyli – Ano Liosia, Attica, Greece. For the needs of the study, time series of Land Surface Temperature (LST) have been processed as extracted from Landsat 8-9 satellite imagery. The analyzed time period is from January 2021 to December 2022. LST data have been extracted from two areas within the landfill, one in the active landfill area and the second one in an area that has been rehabilitated and is no longer active. Furthermore, we selected to study LST data from a bare soil area which is located at a short distance from the landfill in order to find temperature deviation caused by the decomposition processes. The land surface temperatures inside the landfill have been compared with those of the bare soil as well as with the air temperature, which is provided by the weather station of Ano Liosia of METEO (infrastructure of National Observatory of Athens for weather forecasting). It has been observed that the LST in the active area of ​​the landfill is higher by 1°C-2°C compared to that in the inactive area of ​​the landfill, and by 2°C-3°C compared to the bare soil LST. A reversal of this phenomenon has been observed during the snowy winter months due to different snowmelt rates and possibly due to a slowdown of the decomposition process. The air temperature was found to be significantly lower than the LST, as expected.
High-resolution Structure from Motion modelling and 3D printing of Scanning Electron Microscopy data
Authors: Grasemann Bernhard , Bestmann Michel , Kettermann Michael
Published: February 2023

Structure from Motion photogrammetry calculates 3D point clouds through identification of matching features in an overlapping series of pictures, from which textured 3D surfaces can be derived. This method has become increasingly popular in field geology because with the help of drone pictures, high-resolution digital outcrop models, digital elevation models or orthoimages can be produced at very high quality but low-costs.Here, we use secondary electron images with micron-scale resolution to reconstruct the 3D geometry of a c. 400 μm quartz mineral fish using photogrammetry. The quartz fish from a marble ultramylonite from Thassos (Greece) has been extracted by an in situ etching technique (Bestmann et al., 2000, JSG, 22, 1789-1807). 57 secondary electron images captured at various stage rotations and stage tilts in a TESCAN Vega II scanning electron microscope were automatically aligned using the Structure from Motion software Agisoft Metashape (version 1.8.4). In order to increase the precision of the algorithm the background information of the images was removed using Adobe Photoshop and 15 marker points were identified in the images, which also helped to define a scaled coordinate system. We calculated a dense point cloud (c. 2.8 million points) from which a 3D model (c. 600000 faces) was derived on which the secondary electron image information was textured.The tiled 3D model can be used to precisely measure parameters like volume, surface or shapes of the quartz fish either in Agisoft Metashape or from the exported 3D model using more specialized 3D analysis software (e.g. CloudCompare). Furthermore, features at the nanometer-scale like size and orientations of the grain boundaries or crystal faces of the dissolved calcite crystals, which surrounded the quartz fish, can be quantitatively investigated. After cleaning and down-sampling of the exported polygon mesh, the 3D surface can be transformed into a volume and eventually 3D printed. This method offers a great potential for quantitative investigations of the geometry and spatial relationship of microstructures and printed 3D models are a great haptic tool, which can be used in teaching and public outreach.
Application of SOSlope to shallow landslide triggering in Rüdlingen (Switzerland)
Authors: Murgia Ilenia , Giadrossich Filippo , Cohen Denis , Capra Gian Franco , Schwarz Massimiliano
Published: February 2023

The development and application of deterministic models for vegetated slope stability analysis at a local scale is a pivotal issue in international research. Such tools identify mitigation and risk management techniques during increasingly frequent critical rainfall events. In this sense, the SOSlope software, developed by ecorisQ international association (www.ecorisq.org), allows the simulation of hydro-mechanical dynamics that may influence shallow landslides' occurrence, focusing on the progressive activation of root reinforcement in space and time to counteract soil movement. This study presents a reconstruction of an artificially triggered landslide in Rüdlingen (Switzerland), carried out during the Triggering Rapid Mass Movements project, aiming for a back-analysis of the hydro-mechanical conditions leading to its triggering. This experiment allows comparing real-scale data on triggering dynamics of shallow landslides with modeling assumptions and results. Detailed measurements during the investigation and following slope failure were used to calibrate the hydro-mechanical input parameters used in SOSlope and evaluate the modeling capability to reproduce the landslide-triggering conditions and behaviors. Results show a reasonable reconstruction of the complex dynamics leading to the loss of soil stability. In particular, considering the water effect and the force redistribution dynamics during the triggering. SOSlope can quantify the effect of the root reinforcement spatial distribution and passive earth pressure. In addition to quantifying the maximum value of root reinforcement achieved to counteract soil movement, SOSlope enables observing its progressive activation in space and time. Pore water pressure dynamics show a distinctive trend regarding preferential flows in soil fractures and macropores; the decrease of suction stress due to increased water content in the soil matrix was also observed. SOSlope allows for systemic analysis of the landslide event by evaluating the different phases of change in slope stability and identifying the causes that favored their failure. These results are challenging to understand the shallow landslide triggering dynamics on vegetated slopes, given simplified assumptions through simpler models. This tool could support risk management strategies, including green-based solutions, nearby structures and infrastructure, or reforestation activities for slope stabilization. In the latter case, through the software, the structure, composition, and efficiency of the plantation can be checked. Future developments in SOSlope will include the implementation of a triangulated grid mesh to improve computational limitations associated with the raster input data square grid resolution and the inclusion of new tree species for root reinforcement estimation.
Nitrogen reallocation during alpine plant senescence contributed to plant nutrient conservation and ecosystem nitrogen retention
Authors: Zhao Qingzhou , Smith Gabriel , Wang Peng , Hu Lingyan , Ma Miaojun , Averill Colin , Crowther Thomas , Hu Shuijin
Published: February 2023

To conserve limiting nitrogen (N) in alpine ecosystems, herbaceous plants resorb and reallocate N from senescing tissues. However, the extent of N resorption and reallocation in aboveground tissues, coarse roots, fine roots and their relative contributions to whole-plant N conservation and ecosystem N retention remain poorly understood. Utilizing N stable isotope (15N) as a tracer, we quantified N partitions and N retranslocation efficiencies (NRE, % of N changes for each N pool) during senescence among different plant organs in a Tibetan alpine system. We found that compared to the N pools at the peak biomass stage, substantial 15N infine roots (FR, 39.93%) and aboveground tissues (shoot, 50.94%) was retranslocated primarily to coarse roots (CR, an increase of 79.02% in 15N) and non-extractable soil organic matter (an increase of 37.39% in 15N), corresponding to a temporal shift of plant trait syndrome from poor conservation to strong conservation during senescence. 15N in particulate organic matter and mineral-associated organic matter fractions during the senescence stage increased by 29.80% and 24.30%, respectively, but microbial biomass 15N significantly decreased. Our results illustrate the key role of N retranslocation to coarse roots and organic matter in N retention and the dual role of plant roots and organic matter as N sink and source in the plant-microbe-soil system. These findings suggest that plant N retranslocation and seasonal trait alternation facilitate the spatial and temporal coupling between plant N demand and bioavailable N supply in N-limiting alpine systems. 
Stress Drop Segmentation in the Northern Chilean Subduction Zone: from Interface to Deep Seismicity.
Authors: Folesky Jonas , Hofman Rens , Kummerow Jörn
Published: February 2023

We produced a comprehensive stress drop catalog for northern Chile. To improve reliability, we applied a combination of two different stress drop estimation approaches. The result is a mapped stress drop distribution for more than 30,000 events covering the subduction zone from the trench to a depth of about 150 km. The stress drops were computed on the basis of a recently updated version of the IPOC seismic catalog, now spanning the years 2007 to 2021, using the spectral stacking technique as well as the spectral ratio technique. The resulting distribution reveals a segmentation of median stress drop values for different seismogenic parts of the subduction zone: We find the lowest stress drops for interface events and slightly increased values for the two parallel bands of seismicity below, which lie inside the subducting plate. The upper plate events, show higher stress drops and the intermediate depth events bear the highest median stress drop. The variation of the median stress drops between classes is small: from 1.3 MPa for interface events to about 3.2 MPa for intermediate depth events. This being the values of the spectral ratio results. Using spectral ratios we find the exact same order of median stress drops between the classes with a range of 2.0 MPa to 5.8 MPa for interface and intermediate depth events, respectively. Interestingly, there is no stress drop increase with dept in the uppermost ~80 km, i.e. within each of the classes except for the intermediate depth events. Additionally, we observe spatial stress drop variability, a noticeable increase with distance from the plate interface, and temporal variability connected with the two megathrust events in the study region, the Mw7.6 2007 Tocopilla event and the Mw 8.1 Iquique event. 
Impact of the solar activity on the non-linearity of the statistical dependency between solar wind and the inner magnetosphere
Authors: Hoilijoki Sanni , Lipsanen Veera , Osmane Adnane , Kalliokoski Milla , George Harriet , Turc Lucile , Kilpua Emilia
Published: February 2023

Solar wind variations and transients are the main driver of the dynamics of the Earth’s magnetosphere. Interplanetary coronal mass ejections (ICME) cause the largest variations in the near-Earth space, but significant geomagnetic activity can also be driven by high-speed streams (HSSs) and stream interaction regions (SIRs). Solar wind – magnetosphere interactions drive fluctuations in the inner magnetosphere and impact the electrons in the outer radiation belt. Ultra low frequency (ULF) waves in the Pc5 range (2-7mHz) can accelerate electrons in the inner magnetosphere via drift resonance and cause changes in the electron flux up to several orders of magnitude. The different solar wind structures, ICMEs and HSSs/SIRs have been found to have different impact on the ULF waves and electrons in the inner magnetosphere. In this study we use mutual information from information theory to study the statistical dependency of the ULF waves and radiation belt electrons on the solar wind parameters and fluctuations over the solar cycle 23. Unlike Pearson correlation coefficient mutual information can also be used to investigate non-linear statistical dependencies between different parameters. We calculate correlation coefficients separately for each year and find that the non-linearity between the solar wind parameters and some magnetospheric parameters is higher during solar maximum when most of the geomagnetic activity is driven by ICMEs, while the non-linearity decreases during the declining phase, as larger portion of the geomagnetic activity is driven by HSSs and SIRs. To investigate further if the change of the ratio of ICMEs and HSSs is the possible cause of the changes in the non-linearity during the solar cycle, we calculate the correlation coefficients separately during ICMEs, HSSs/SIRs and quiet solar wind.
E-field at a low-activity comet derived from cometary ion velocity distributions
Authors: Moeslinger Anja , Nilsson Hans , Stenberg Wieser Gabriella , Williamson Hayley
Published: February 2023

The ion spectrometer ICA onboard the Rosetta mission has provided us with detailed measurements of the plasma environment around comet 67P/Churyumov-Gerasimenko. The distribution of cometary ions is an important indicator for the cometary plasma environment and its interaction with the solar wind. The cometary ion production at a comet decreases with increasing radial distance from the comet. The fluxes of observed ions are therefore also expected to fall off proportional to their point of origin relative to the comet. Due to electric fields, ions that are born further away are observed at higher energies at the spacecraft. The exact relation between the flux and the observed energy depends on the density distribution of cometary ions and the electric field around the comet.We derive the bulk flow properties of the cometary pickup ion population with a fitting procedure. In our study, cometary pickup ions are all heavy ions with an energy above 40 eV as observed by ICA. The particle drift speed of the bulk flow can be used to estimate the average local electric field. This gives us a 3D estimate for the electric field close to the comet nucleus. Using this E-field estimate, we can back-trace the observed particles to determine an approximate location of where they were born. This ionisation point is further away for particles with higher energies. The relation between the flux of the observed ions and their origin provides us with information about the inhomogeneity of the cometary plasma environment between the observation point (30 km from the nucleus) and the ionisation point of the particle (hundreds of km away from the nucleus). We will present results of the ion distribution of cometary pickup ions above 40eV on a selected day (April 19th, 2016) of the Rosetta mission, along with the derived electric field estimate close to the nucleus. We will also show the results and implications of the particle trajectory backtracing.
Aseismic slip behavior along the central section of the North Anatolian Fault: insights from geodetic observations.
Authors: Jara Jorge , Jolivet Romain , Ozdemir Alpay , Dogan Ugur , Çakir Ziyadin , Ergintav Semih
Published: February 2023

Recent observations suggest seismogenic faults release elastic energy through a wide variety of slip modes covering a spectrum from sudden rapid earthquakes to slow aseismic slip. Aseismic slip releases energy very slowly without radiating seismic waves and plays an important role in the initiation, propagation, and arrest of large earthquakes. Aseismic slip is thought to be influenced by the presence/migration of fluids, stress interactions through fault geometrical complexities, and/or fault material heterogeneities. Descriptions of occurrences of aseismic slip at the surface and depth are hence required to feed into models and eventually characterize the factors controlling the occurrence of slow, aseismic versus rapid, seismic fault slip.We focus on the central segment of the North Anatolian Fault, which has been creeping since at least the 1950s. This region was struck by the Mw 7.3 Bolu/Gerede earthquake in 1944, and since then, no earthquake of magnitude greater than 6 has been recorded. During the 1960s, aseismic slip was discovered as a wall built across the fault in 1957 was being slowly offset. Geodetic studies (InSAR, GNSS, and creepmeters) focused on capturing and analyzing aseismic slip around the village of Ismetpasa. Creepmeter measurements during the 1980s and 2010s, along with InSAR time series analysis, suggest that aseismic slip occurs episodically rather than persistently.We use Sentinel-1 time series and GNSS data to provide a spatio-temporal description of the kinematics of fault slip. We show that aseismic slip observed at the surface is coincident with a shallow locking depth and that slow slip events with a return period of 2.5 years are restricted to a specific section of the fault. We contrast such results with GNSS time series analysis of a local network, confirming our findings. In addition, we discuss the potential rheological implications of our results, proposing a simple alternative model to explain the local occurrence of shallow aseismic slip at this location.
PREVENIR: Japan-Argentina Cooperation Project for Heavy Rain and Urban Flood Disaster Prevention
Authors: Miyoshi Takemasa , Saulo Celeste , Otsuka Shigenori , Ruiz Juan , Skabar Yanina G. , Amemiya Arata , Ushio Tomoo , Tomita Hirofumi , Ushiyama Tomoki , Konishi Masaya
Published: February 2023

This presentation provides an overall summary of the project PREVENIR and recent activities about data assimilation and numerical weather prediction (NWP) research. PREVENIR is an international cooperation project between Argentina and Japan since 2022 for five years under the Science and Technology Research Partnership for Sustainable Development (SATREPS) program jointly funded by the Japan International Cooperation Agency (JICA) and the Japan Science and Technology Agency (JST). The main goal is to develop an impact-based early warning system for heavy rains and urban floods designed for two highly vulnerable urban basins in Argentina: one located in Buenos Aires Province and the other in Córdoba Province. PREVENIR takes advantage of leading research on simulations and Big Data Assimilation (BDA) with the Japan’s flagship supercomputer “Fugaku” and its predecessor “K” and develops a total package for disaster prevention, namely, monitoring, quantitative precipitation estimates (QPE), nowcasting, BDA and NWP, hydrological model prediction, warning communications, public education, and capacity building. Here, the Japanese leading institutions in the scientific research and operational services, i.e., RIKEN, Osaka University, the International Centre for Water Hazard and Risk Management (ICHARM), and the Japan Meteorological Agency (JMA) closely work with the Argentinian counterparts, i.e., the National Meteorological Service, the National Water Institute, and the National Research Council of Argentina under the strong support of JICA, JST, and Argentinian Foreign Affairs Ministry. Heavy rains and urban floods are important global issues under the changing climate. The total package for disaster prevention will be the first of its kind in Argentina and will provide useful tools and recommendations for the implementation of similar systems in other parts of the world.
Meridional Saharan dust transport towards higher latitudes
Authors: Varga György , Rostási Ágnes , Csávics Adrienn , Dagsson-Waldhauserova Pavla , Meinander Outi , Gresina Fruzsina
Published: February 2023

Over the past decades, an increasing number of Saharan dust storm events have been identified across Europe, using satellite measurements and imagery, numerical simulation data, meteorological analyses, air mass dispersion trajectories and surface observations, thus excluding subjective forcing factors. Both the frequency and intensity of dust storm events have been increasing over the last decade.Saharan dust reached the Carpathian Basin at least 250 times between 1979 and 2022. The episodes of intense dust deposition in Hungary clearly showed the effect of the downwelling of high-latitude jet streams, leading to (1) extreme weather events and intense dust storms in the Atlas region and (2) increased atmospheric meridionality, which transported the large amounts of dust northwards.To identify such events, we started our research in the North Atlantic region, where we identified 15 Saharan dust storm events in Iceland between 2008 and 2020, two of which were also surface sampled. The scope of these studies has now been extended to 1980 to 2022 to identify further events. Laboratory analyses of the sampled dust material have found abundant quartz particles larger than 100 µm, indicating that large dust particles can sometimes travel thousands of kilometres.Similar studies have been initiated in the region of Finland, where 59 Saharan dust storm events were identified between 1980 and 2022. Note that we also found 22 dust storm events from the Aral-Caspian region and 5 episodes with Middle Eastern sources.The research was supported by the NRDI projects FK138692 and RRF-2.3.1-21-2021.
Radiation belt particle diffusion, drift and advection via cyclotron interactions
Authors: Allanson Oliver , Bortnik Jacob , Ma Donglai , Osmane Adnane , Albert Jay
Published: February 2023

There is a growing body of observational, theoretical and experimental evidence to indicate that a proper description of radiation belt charged particle transport will require new mathematical models, i.e. new partial differential equations. One leading candidate is to extend the ‘standard diffusion equation’ to a more general Fokker-Planck equation in order to include advection coefficients. Ideally, these advection (first-order transport) coefficients should be parameterized by plasma and VLF/ELF electromagnetic wave parameters in a similar manner to that used for the diffusion coefficients. To the authors' knowledge, this goal has not yet been achieved - at least not to obtain an equation that can be/has been implemented into operational global scale numerical models.In general, advection coefficients are in fact a combination of both ‘drift coefficients’ and derivatives of the diffusion coefficients. In the standard quasilinear formalism, this combination produces advection coefficients that are identically zero because of specific constraints imposed via the Hamiltonian structure, with a derivation often attributed to Landau/Lichtenberg & Lieberman [1].In this paper [2] we present a new theory that incorporates and builds upon the ‘weak turbulence/quasilinear results’ of [3,4] and demonstrates the breaking of the ‘Landau-Lichtenberg-Liebermann condition’ for the case of high wave amplitudes, or equivalently small timescales.We therefore obtain:(i) the standard quasilinear results for small wave amplitudes and long timescales;(ii) and non-zero advection coefficients - as well as diffusion coefficients - that are valid for short timescales (high wave amplitudes).These limiting timescales are determined by the electromagnetic wave amplitude. This also demonstrates that one can use what may be considered ‘quasilinear methods’ to obtain interesting new results for ‘nonlinear/high-amplitude’ waves in radiation belt modelling. We verify the results using high-performance test-particle experiments.References[1] A.J. Lichtenberg, and M.A. Lieberman, “Regular and Chaotic Dynamics”, 2nd Ed., Springer, 1991[2] O. Allanson et al (in prep)[3] D.S. Lemons, PoP, 19, 012306, 2012[4] O. Allanson, T. Elsden, C. Watt, and T. Neukirch, Frontiers Aston. Space Sci., 8:805699, 2022
Cumulative Effects of Beaver Ponds and Forest Harvest on Streamwater Chemistry in Boreal Watersheds
Authors: Lam Wai Ying , Mitchell Carl
Published: February 2023

Canada’s boreal forests provide many important ecosystem services, including but not limited to biomass production, habitat provisioning, and soil and water protection. As forests are an important part of Canada’s economy and landscape, it is crucial that they are managed sustainably. In the province of Ontario, sustainable forest management is largely based on emulating natural disturbances. With respect to stream biogeochemistry, beaver ponds are one of the most common and significant disturbances against which to compare.  

Thus, there is a need to further our understanding of how beaver ponds and forest management interact and modify the effects of one another. This study examined a suite of surface water chemistry variables, with a focus on the bioaccumulative neurotoxin methylmercury, in 28 headwater catchments across 3 years in northwestern Ontario. Some were undisturbed; some were impacted by active or abandoned beaver ponds; some were undergoing active harvest, while others were harvested previously; and some were impacted by active or abandoned beaver ponds and new or previous harvest. 

Forest harvest impacts on organic carbon, suspended sediments, and mercury fell largely within the range of natural variation seen at undisturbed sites, except where significant soil and water disturbance from stream crossings occurred upstream. Pond impacts were highly variable, but more strongly related to catchment characteristics (such as mean slope and channel length) than to pond characteristics (such as shape and in-pond vegetation cover). Though downstream impacts were found to be greatest at a new pond in a catchment undergoing active harvest, pond and harvest impacts were not consistently additive in catchments where both occurred. Understanding the impacts of beaver ponds in conjunction with forest harvest is important for predicting the ultimate effectiveness of management decisions aimed at protecting terrestrial-aquatic ecosystems commonly affected by both disturbances.  
How do environmental mesoscale heterogeneities influence the trade-wind cloud organization?
Authors: Dauhut Thibaut , Couvreux Fleur , Bouniol Dominique
Published: February 2023

Cumuli clouds in the trade winds are a great source of uncertainty for the future climate as their net radiative effect is hardly represented in global models. The spatial organization of these clouds, that drives their radiative effect, has been categorized into 4 major patterns: Sugar, Flower, Gravel and Fish (Bony et al. 2020). The processes governing their spatial organization and the relationships with the environmental properties remain however unclear. This study investigates the sensitivity of the Flower organization to the environmental mesoscale heterogeneities in water vapor and winds. A case of Flower organization, producing 100-km wide cloud clusters, is selected from the EUREC4A-ATOMIC campaign that took place east of Barbados in January-February 2020. A Large-Eddy Simulations using the Meso-NH model and a 100-m horizontal grid-spacing has been extensively validated by satellite and aircraft high-resolution observations (Dauhut et al., 2022) and serves as a reference. By removing alternatively the humidity or the wind heterogeneities, we show that mesoscale humidity anomalies play a critical role in driving cloud organisation into Flower. Further investigations indicate that humidity heterogeneities in the cloud layer influence the development of a shallow mesoscale circulation and have a larger impact than the heterogeneities in the sub-cloud layer. Different chains of processes are proposed to explain such a sensitivity.