bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence and evolution of switchbacks between 13.3 to 70 solar radii: PSP Observations
Authors: Jagarlamudi Vamsee Krishna , Raouafi Nour E , Bourouaine Sofiane , Mostafavi Parisa , Larosa Andrea
Published: February 2023

Since its launch, the Parker Solar Probe (PSP) mission revealed the presence of numerous fascinating phenomena occurring closer to the Sun, such as the presence of ubiquitous switchbacks (SBs). The SBs are large magnetic field deflections of the local magnetic field relative to a background field. We investigated the statistical properties of the SBs during the first ten encounters between 13.3 and 70 Solar Radii using data from the SWEAP and FIELDS suites onboard PSP . We find that the occurrence rate of small deflections with respect to the Parker spiral decreases with radial distance (R). In contrast, the occurrence rate of the large deflections (SBs) increases with R, as does the occurrence rate of SB patches. We also find that the occurrence of SBs correlates with the bulk velocity of the solar wind, i.e., the higher the solar wind velocity, the higher the SB occurrence. For slow wind, the SB occurrence rate shows a constantly increasing trend between 13.3 and 70 solar radii. However, for fast wind, the occurrence rate saturates beyond 35 solar radii. Sub-Alfvenic regions encountered during encounters 8-10 have not shown significant SBs. This analysis of the PSP data hints that some of the SBs are decaying and some are being created in-situ.
The effect of steady-state flow on induced stresses along displaced faults
Authors: Cornelissen Pavan , Jansen Jan Dirk
Published: February 2023

Pore pressure changes due to fluid injection or withdrawal alter the rock stresses, which may potentially induce seismic events. Activities that have been associated with induced seismicity include geothermal energy production, subsurface gas storage, and natural gas production. Physics-based models are required to gain insight in the processes that lead to induced seismicity. When computing induced stresses with such models, a commonly made simplification is the assumption of uniform pressure changes across the entire reservoir. In reality, pressure gradients arise due to fluid production or injection. Here, we assess the effect of non-uniform pressure fields under steady-state flow conditions on induced stresses. We employ (semi-)analytical techniques to compute the corresponding pressure field and fault stresses. We are particularly interested in reservoirs with displaced faults (i.e., cases with nonzero fault offset), as shear stresses tend to concentrate at the reservoir corners along the faults. The stress profile along the fault becomes asymmetric under steady-state flow. The effect of fluid flow on fault stresses is larger in case of injection than in case of depletion. Injection with up-dip flow results in increased zones of fault slip near the bottom of the reservoir, while injection with down-dip flow results in increased slip near the top of the reservoir. The significance of steady-state flow on induced stresses can be estimated from the ratio of the average pressure change along the fault and the applied pressure gradient. The effect of steady-state flow is most relevant at the start of production or injection and diminishes with time. Thus, the effect of steady-state flow is only expected to be relevant when initially critically stressed faults are present. For non-critically stressed faults, the assumption of uniform depletion or injection is expected to be reasonable. An order-of-magnitude estimate of the effect of steady-state flow across displaced faults in the Groningen natural gas reservoir shows that the effect on fault stresses is probably negligible. A similar estimate of the effect in typical low-enthalpy geothermal doublets indicates that steady-state flow may possibly play a small role, in particular close to the injector. Nevertheless, site-specific assessments are necessary to quantify the effect in greater detail.
Dynamics of small-scale turbulence in the upper ocean under the action of currents and internal waves
Authors: Ostrovsky Lev , Gladskikh Daria , Soustova Irina , Troitskaya Yuliya
Published: February 2023

We study the evolution of a turbulent layer in a stratified ocean layer using the theory of unsteady turbulent flows in a stratified fluid developed in [1] and subsequent works. The theory starts from a kinetic equation for turbulence parameters and results in the set of equations involving the mutual transformation of the kinetic and potential energies of turbulence that is shown to significantly affect the overall dynamics of energy exchange between small-scale turbulence and mesoscopic motions and the formation of the upper mixed layer. Besides, this approach allows an account for some important but usually neglected effects such as the dependence of vertical anisotropy of turbulence on stratification. Notably, the transformation between kinetic and potential energies eliminates the restriction on the existence of turbulence at large Richardson numbers.  The results are applied to the analysis of in situ data for turbulence evolution under the action of shear flows and internal waves, obtained in different regions that are significant for climate research, including the upper equatorial ocean. The fundamental role of potential energy in the formation of a turbulent flow is demonstrated.The work was supported by RSF project No. 23-27-00002.[1] Ostrovsky L.A., Troitskaya Yu.I. (1987) A model of turbulent transfer and dynamics of turbulence in a stratified shear flow. Izvestiya, Atm. and Oceanic Phys., 23(10), 767-773 (1987).
Sensitivity of a 3D-model biogeochemistry to ocean physics forcing frequency 
Authors: Feudale Laura , Salon Stefano , Cossarini Gianpiero , Bolzon GIorgio , Clementi Emanuela
Published: February 2023

The frequency of ocean dynamics model output forcing transport-biogeochemical models in off-line coupling configuration can be a critical aspect when mesoscale and high variability dynamics are simulated. In the present work, the sensitivity of ocean dynamics frequency on biogeochemistry is evaluated for the Copernicus Mediterranean Sea forecasting system.

The current off-line coupling strategy between Med-BIO and Med-PHY (respectively, biogeochemical and physical components of the Mediterranean Sea operational system embedded in the Copernicus Marine Service) is based on the forcing of daily mean fields (3-D potential temperature, salinity, current velocity, vertical eddy viscosity, and 2-D wind stress, sea surface height) produced by the hydrodynamic component based on the coupled NEMO-WW3 modeling system including the OceanVar 3DVAR data assimilation model. The daily means are then linearly interpolated to extract data at higher temporal frequency (30 minutes), which are then used by the MedBFM system, through the OGSTM model, to transport (via advection and diffusion) the biogeochemical tracers (e.g. nutrients). The biogeochemical reactions are then computed by the Biogeochemical Flux Model (BFM).

In the present work the outputs of 1-year long runs (year 2019) produced by the OGSTM-BFM off-line coupled with NEMO-OceanVar using physical forcing at different temporal frequencies, 6-hr, 4-hr, 2-hr averages, are evaluated comparing them with a run forced by the conventional 24-hr average. The sensitivity of the high frequency forcing, which is basically related to a finer temporal resolution of the physical processes acting on the vertical dimension, indeed reduces the approximation related to the daily averaging and is investigated and discussed measuring the impact on the biogeochemical product quality. Improvements in the western Mediterranean area and Ionian Sea, especially during the winter season, are observed: this corroborates the fact that induced higher variability of dynamical processes is important for the quality of biogeochemical variables.
Spatiotemporal analysis and modeling of nonstationarity in hydrological time series
Authors: Kumar Nishant , Kumar D. Nagesh , Roy Tirthankar
Published: February 2023

Detection of nonstationarity in hydrological time series is most commonly done through one or two unit root tests, which usually do not account for all the possible reasons that could induce nonstationarity in a time series. To overcome this, we carried out five different unit root tests, i.e., Augmented Dickey-Fuller (ADF) test, Kwiatkowski Phillips Schmidt Shin (KPSS) test, Phillips Perron (PP) test, Variance Ratio (V ratio) test, and Leybourne McCabe (LMC) test, along with the line spectrum analysis in the frequency domain. These tests were conducted on daily rainfall data at forty contiguous grid points around the Malaprabha basin in India using data from the Indian Meteorological Department. The main goal was to find different nonstationary time series and investigate the spatiotemporal patterns of the nonstationarity and use that information to further develop nonstationary time series models through three different modeling approaches, i.e., Seasonal Autoregressive Integrated Moving Average (SARIMA), Exponential Smoothing (ES), and Long Short-Term Memory (LSTM). The performance of these models was evaluated on the basis of Nash Sutcliffe Efficiency (NSE) and R2 value. 
ML approaches to flood susceptibility mapping at the country scale
Authors: Dawson Geoffrey , Butt Junaid , Fraccaro Paolo , Jones Anne
Published: February 2023

Flooding is one of the most costly disasters in the UK, and its impact is projected to increase under climate change. Detailed, accurate and high resolution modelling and mapping of flood hazards are therefore essential to enable climate change adaptation. However, high resolution physics-based flood inundation models are extremely computationally intensive to run, presenting a challenge when mapping flood risk at the country scale, especially when working with ensembles of driving scenarios to account for uncertainty. Furthermore, efficient physical modelling for a target location and/or event required a priori categorisation of dominant flood type (for example fluvial or pluvial), which determines the selection and configuration of appropriate models. In reality, floods at scales beyond a local level are often a combination of multiple flood types. In recent years, machine learning approaches to mapping flood susceptibility have grown in popularity, enabled by large volumes of geospatial and weather/climate data from which explanatory flood factors can be derived. In this study, we develop a pluvial/fluvial flood susceptibility model for England, using high quality open datasets (elevation, land use, soil type, location of water bodies, rainfall) to derive hydrologically-meaningful features, and an open flood inventory dataset to sample flooded/non-flooded points. We train and test the model with grouped cross-validation hyper-parameter tuning for repeated samples of the data on a regular grid, where testing is carried out on unseen grid squares. We discuss the relative performance of different machine learning algorithms, including Random Forest and XG Boost, and assess the computational intensity and scalability of the model across training and inference phases. We also consider the potential of machine learning approaches to provide uncertainty estimates and, via explainable AI techniques, the sensitivity of the predicted flood probability to explanatory flood factors at any given location. Finally, we reflect on the part the modelling approach can play as part of a range of tools to meet the needs of consumers of flood risk information across multiple economic sectors.
Deep learning based classification of multinational airborne laser scanning data
Authors: Walicka Agata , Pfeifer Norbert
Published: February 2023

Airborne laser scanning (ALS) point clouds are commonly acquired to describe a 3D shape of terrain and attributes of objects and landforms located on it. They proved to be useful in a variety of applications, including geometrical characterization of both man-made and natural objects and landforms. Usually, the first step of point cloud processing is classification. As a result, its accuracy highly influences the results of subsequent processing. Therefore, reliable and automatic point cloud classification is of key importance in most of the ALS data applications.Recently, deep learning techniques attracted the attention of the community in the context of point cloud classification. However, the reproducibility of the trained deep learning networks remains unexplored because there is too little accessible and precisely classified 3D training data. Recently many countries have published their national ALS data sets. This initiative leads to promising options for deep learning classification of point clouds as it allows for comprehensive training of deep networks.In this study we present the investigations that aimed at creation of a universal, deep learning based classifier that will be able to classify point clouds of varying characteristics. The experiments were carried out using selected parts of data sets that have been made available by three European countries: Poland, Austria and Switzerland. The point clouds were classified into four classes: ground and water, vegetation, buildings and bridges, and others. The results of the experiments showed that it is possible to achieve high overall accuracy of the classification for the ground and water (above 98%), vegetation (92-97%, depending on a test site), and building and bridges (92-96%, depending on a test site). A lower overall accuracy was achieved for class others because of a very high variability of geometry of objects that belong to this class. Furthermore, in some cases, adding training data from a different country to the initial training data resulted in improved classification accuracy in selected classes and reduced dataset-specific errors.As a result, this study proves that it is possible to create a universal, deep learning based classifier that will be able to maintain high classification accuracy while it processes data sets of different characteristics.
Transitions in the Northern Hemisphere glaciation process
Authors: Talento Stefanie , Ganopolski Andrey , Willeit Matteo
Published: February 2023

We use the new Earth system model of intermediate complexity CLIMBER-X to investigate pathways of Northern Hemisphere (NH) glaciation. We perform experiments in which different combinations of orbital forcing and atmospheric CO2 concentration are maintained constant in time. Each model simulation is run for 300 thousand years (kyr) starting from present-day conditions, and using an acceleration technique with asynchronous coupling between the climate and ice sheet model components.We find that in the pathway to a NH glaciation, several bifurcations might occur. The bifurcations separate a diversity of stable configurations, which have different spatial and temporal prints. We identify four different bifurcations, separating five different equilibrium states: (i) completely ice-free conditions, (ii) present-day (ice only over Greenland), weak glaciation (with ice coverage north and west of Hudson Bay, Greenland and Scandinavia), (iv) Last Glacial Maximum – type of glaciation (with large North American and medium-size Eurasian ice sheets) and (v) mega-glaciation (full ice coverage over both North America and Eurasia).The transitions are also clustered in terms of differential timescales. While the North-American continent full glaciation has a development timescale of ~ 100 kyr, an extensive ice coverage of the Eurasian continent involves a much longer time-frame of ~ 250 kyr. This could explain why a complete glaciation of the Eurasian continent was never observed. This result is also consistent with previous studies in the sense that one glaciation cycle is not long enough for the Eurasian ice sheet to fully grow.
Understanding community acceptance of large-scale marine infrastructure projects.
Authors: Kadiri Margaret , Barcena Alejandro , Hanco Marco
Published: February 2023

In recent years there has been growing interest globally in energy transition from fossil fuel-based systems of production to renewable energy sources. However, experiences from offshore wind energy suggest that lack of local community acceptance associated with the siting of renewable energy infrastructure projects poses a significant challenge. In principle, there is public support for marine energy in the UK, with UK government funded research indicating 79% of public respondents in large-scale nationally representative surveys have expressed support (BEIS, 2020). However, opposition by local communities to large-scale infrastructure projects is likely to occur, possibly arising from the social, spatial and psychological impacts having to do with place attachment and displacement. Place attachment zeroes in on the ties that bind people and places together and give meaning to people’s lives and their identity. We have seen, through the coronavirus pandemic for example, the effects of relocalization, the connection people have to local places and the sense of identity that can come from those connections. On the other hand, displacement defines the ways in which place attachment can be threatened, changed and disrupted, and weakened by rapid extensive changes that people do not feel any sense of control over, and it usually leads to a sense of threat, uncertainty, anxiety and pushback. Although intangible, it is necessary to appreciate the connections people have with landscapes and seascapes and for such ties to be taken into account, in addition to environmental impacts, when assessing the roll out of marine energy infrastructure projects. This will secure community acceptance for rapid and extensive change and ensure an equitable transition. In this study, Morlais Tidal Demonstration Zone in Holy Island, Anglesey was used as a case study to examine the role of place attachment and displacement in shaping local community acceptance of large-scale marine energy infrastructure projects, the place attachment related factors involved and how these factors shape the development of such projects. Semi-structured interviews were conducted to obtain qualitative primary data and a mixed-method approach was used to allow for triangulation with secondary quantitative data from various sources. This study also examines socio-environmental outcomes at various scales and their wider implications.
Peatland methane emissions in a changing climate: A 13-year time series of a boreal fen in Northern Finland
Authors: Kübert Angelika , Aurela Mika , Hatakka Juha , Laurila Tuomas , Rainne Juuso , Tuovinen Juha-Pekka , Vekuri Henriikka , Lohila Annalea
Published: February 2023

Boreal peatlands are a major source of global wetland methane emissions. With ongoing climate change, these emissions could rise sharply in future, further enhancing climate change. Yet, long-term studies evaluating the impact of climate change on boreal peatlands are scarce. We have monitored methane emissions at a boreal fen in Lompolojänkkä, Northern Finland (ICOS ecosystem class II site) for 13 years (2007-2019) using the eddy covariance technique, accompanied by measurements of abiotic and biotic variables, such as peat temperature, water level, and vegetation parameters. Peat temperatures strongly drove methane emissions, that is, methane emissions increased significantly with peat temperature. Year-to-year variation in CH4 emissions was correlated to year-to-year variation in peat temperatures. Annual variation in water levels had no significant impact. Our results confirm that peat temperature explains CH4 variation to a large extent. In this presentation, we will further evaluate the role of snow cover and melt on CH4 emissions in spring.
Dynamical Constraints on regional Projections of Extreme Precipitation Events
Authors: Pieper Patrick , Zhu Donghe , Fischer Erich , Pfahl Stephan
Published: February 2023

Extreme precipitation events cause major ecological and societal hazards (e.g. river flooding and landslides). Aggravatingly, climate change will likely exacerbate extreme precipitation events on a global scale. Scientifically even more concerning, however, are remaining major uncertainties in projections of regional extreme precipitation events, which hamper and complicate local adaptation measurements around the globe. The arguably largest source of these remaining uncertainties stems from climate models feuding about the dynamic evolution of atmospheric circulation; atmospheric circulation governs moisture transport and profoundly affects the location of extreme precipitation events as well as their severity around the globe. We exploit this feud among climate models to narrow down the arguably largest source of uncertainttiesin projections of extreme precipitation events through a storyline approach. For a given location, the approach: (i) unravels the properties of driving weather systems that repeatedly gave rise to extreme precipitation events in the past, (ii) assesses the fidelity of a large suite of models, participating in the Coupled Model Intercomparison Project 6 (CMIP6), in representing these driving weather systems in historical simulations (1950-2015), and (iii) constrains regional projections of extreme precipitation events based on the ascertained fidelity of models.Here, we present such a storyline approach that dynamically constrains regional projections of extreme precipitation events. Accompanying the outline of the approach, we identify regions that are particularly plagued by uncertain projections of extreme precipitation events and showcase for a subset of these regions how to track down weather systems that repeatedly gave rise to extreme precipitation events in the past.
Temporal decoupling between carbon assimilation and tree growth in temperate oaks
Authors: Rao Mukund Palat , Pacheco-Solana Arturo , Griffin Kevin , Jensen Johanna Elizabeth , Pederson Neil , Oryan Bar , Nixon Troy , Rodriguez Caton Milagros Rocio , Andreu Hayles Laia , Hise Jeremy , Peñuelas Josep , Magney Troy
Published: February 2023

The ‘growing season’ of trees is often assumed to be coupled with climatology (e.g., summer vs winter) and visual canopy phenology cues (e.g., leaf emergence in spring and senescence in autumn). However, green leaves are not always photosynthetically active and actual tree radial growth via cambial cell division is ‘invisible’ since it is hard to see and occurs at micrometer resolution. Therefore, despite the presence of apparently green vegetation, trees may not be assimilating carbon or growing. Here, we study photosynthesis and tree-growth at near-instantaneous timescales using in-situ and satellite remote sensing, point dendrometers, quantitative wood anatomy, and Pulse Amplitude Modulated chlorophyll fluorescence. Tree and leaf-level measurements are being made on eight oak (Quercus spp.) trees in a temperate forest in southern New York, USA. We find that oak trees commence radial growth in the first week of April approximately one-month prior to canopy development that is not completed until the first week of May. Additionally, the development of foliar photosynthetic capacity lags leaf expansion by nearly two weeks. Further, we find that oak growth for the season is completed by late July while photosynthetic activity is maintained for three additional months until early November. Finally, we examine the growth climate sensitivity across a network of 16 oak tree-ring width chronologies distributed across the northeastern US. These relationships suggest that oak earlywood growth relies on carbon assimilated in prior year autumn while oak latewood relies on current year assimilated carbon. Therefore, photosynthesis and tree-growth in Northeastern US oaks occurs asynchronously, since trees don’t reach peak photosynthetic performance the moment leaves emerge or grow through the ‘growing season’.
Linking nearshore morphological change to long term observed sand loss from a mixed sediment beach.
Authors: Townsend Dominique , Leyland Julian , Kassem Hachem , Thompson Charlie , Townend Ian
Published: February 2023

Few studies focus on the changing morphology of the nearshore zone of mixed sediment beaches, despite the fact that these beaches are found across the world. In the UK, these beaches make up ~25% of the coastline, and are often utilised as a first line of defence against coastal flooding. In Pevensey Bay, East Sussex, active beach management (sediment recycling and recharge) maintains the mixed gravel barrier beach to protect around 10,000 properties, culturally significant landmarks and internationally important wildlife sites. During the past 25 years, this management approach has successfully maintained the volume of the upper shingle part of the beach. However, the sandy foreshore area is experiencing a continuing loss of 8000 m3 of sediment per annum.This study seeks to understand the drivers behind the sustained loss of volume. Examination of multibeam bathymetry data revealed the presence of transverse finger bars with a wavelength of approximately 80 – 120 m, orientated at 45 degrees from the shoreline in the subtidal zone extending between the -3.0 to -6.0 mOD contours. Sediment grab samples taken perpendicular to the crests and troughs, revealed the surface sediments to be comprised of very well sorted fine sand, with D50 ranging between 150 – 169mm. Strong tidal currents flowing over these bed features modulate the sea surface roughness which can be detected in the X-band radar reflectance imagery. Using weekly averages of X-band radar reflectance imagery we show that the bars were a permanent feature over the 18-month period of observation and provide an indicative migration rate of approximately one wavelength a year to the east, which was validated against monthly bathymetric data. This novel approach of studying mobile sea bed features revealed a steady migration rate during the winter months, and virtually no movement during the summer period, suggests that the movement of the bars is driven by relatively higher energy south westerly waves. It is thought that the movement of these bars may be linked to erosive and accretive pulses which move easterly across the bay on the upper beach face. Understanding the process dynamics and broader role within the bay-wide sediment budget of these features is essential in comprehending the loss of sediment from the bay and will contribute to the future sustainable management of the site, where the management strategy for the next 100 years is currently under review.
Long-term study of the summer wind variability in the mesosphere and lower thermosphere over nearly two decades at middle and high latitudes
Authors: Jaen Juliana , Renkwitz Toralf , Chau Jorge , Liu Huixin , Jacobi Christoph , Tsutsumi Masaki , Gulbrandsen Njål
Published: February 2023

Winds at the mesosphere and lower thermosphere have been measured by partial reflection radars and specular meteor radars for almost two decades (2004-2022) over Germany and Norway (i.e., middle and high latitudes, respectively). Continuous wind measurements during the mentioned period are important to understand their long-term behavior. The zonal mean wind climatology displays an eastward wind during the winter months and a westward summer jet below ~85km at middle latitudes (~90km at high latitudes). Above the mentioned height, an eastward wind jet is observed. In the meridional wind component, the southward summer wind displays amplitudes between 4 and 5 times less intense than the westward jet. We studied the intensity of the summer wind components, the long-term variability and the possible connection to external forcing (i.e. El Niño-Southern Oscillation, and quasi-biennial oscillation, solar activity and geomagnetic activity). Analyzing the summer winds for low and high geomagnetic activity classified with the Ap index, there is a significant difference between both cases suggesting disturbances in the wind due to high geomagnetic activity. The long-term study shows significant trends at middle latitudes in the monthly summer values of the westward summer jet. As a consequence of the increase in the westward wind, a decrease in the southward component is observed at the same latitudes. While at high latitudes the eastward jet shows a decreasing velocity during July.
Doubling protected land area may be inefficient at preserving the extent of undeveloped land and could cause substantial regional shifts in land use
Authors: Di Vittorio Alan , Narayan Kanishka , Patel Pralit , Calvin Katherine , Vernon Chris
Published: February 2023

Projection of land use and land cover change is highly uncertain yet drives critical estimates of carbon emissions, climate change, and food and bioenergy production. We use new, spatially-explicit land availability data in conjunction with a model sensitivity analysis to estimate the effects of additional land protection on land use and cover. The land availability data include protected land and agricultural suitability and are incorporated into the Moirai land data system for initializing the Global Change Analysis Model (GCAM). Overall, decreasing land availability is relatively inefficient at preserving undeveloped land while having considerable regional land use impacts. Current amounts of protected area have little effect on land and crop production estimates, but including the spatial distribution of unsuitable (i.e., unavailable) land dramatically shifts bioenergy production from high northern latitudes to the rest of the world, as compared to uniform availability. This highlights the importance of spatial heterogeneity in understanding and managing land change. Approximately doubling current protected area to emulate a 30% protected area target may avoid land conversion by 2050 of less than half the newly protected extent while reducing bioenergy feedstock land by 10.4% and cropland and grazed pasture by over 3%. Regional bioenergy land may be reduced (increased) by up to 46% (36%), cropland reduced by up to 61%, pasture reduced by up to 100%, and harvested forest reduced by up to 35%. Only a few regions show notable gains in some undeveloped land types of up to 36%. Half of the regions can reach the target using only unsuitable land, which would minimize impacts to agriculture but may not meet conservation goals.A.V. Di Vittorio, K.B. Narayan, P. Patel, K. Calvin, C.R. Vernon (2022). Doubling protected land area may be inefficient at preserving the extent of undeveloped land and could cause substantial regional shifts in land use. GCB Bioenergy, 00:1-23. http://doi.org/10.1111/gcbb.13
Building confidence in STEM students through breaking (unseen) barriers
Authors: Heron Philip , Williams Jamie
Published: February 2023

Science, technology, engineering, and math (STEM) subjects have historically struggled to be inclusive and accessible to students from diverse backgrounds. The field of geoscience, in particular, has also had challenges in diversity with respect to staff and student recruitment. The consequence of non-inclusive practices still propagates today, with certain demographics not engaging in STEM activities. As a result, there needs to be conscious efforts to adopt equity, diversity, and inclusive (EDI) initiatives for subjects such as geoscience to grow. In this submission, we outline the steps we have taken to break down known (and unknown) barriers to education in the teaching of a science outreach course to a diverse student body. Our outreach course, Think Like A Scientist, has been running in a number of English prisons since 2019, and starts in Canada in 2023. This course won the EGU Outreach Award in 2019. Although the programme is tailored to the restrictive prison environment, the application of its core principles to education are fundamental EDI practices that could be beneficial to a wide audience. In this submission, we outline our reasoning for specific pedagogical choices in the classroom when working with students that have low confidence in STEM education, and we highlight the need for engagement that is not only relatable, accessible, and inclusive but also offers encouragement. An accompanying publication of this work was published in Geoscience Communication in 2022 (https://doi.org/10.5194/gc-5-355-2022).
Controlling earthquake-like instabilities in the laboratory
Authors: Stefanou Ioannis , Tzortzopoulos Georgios , Braun Philipp , Gutierrez-Oribio Diego
Published: February 2023

We perform laboratory experiments of decametric scale using a novel triplet apparatus (Fig. 1) that allows (a) to reproduce earthquake-like instabilities and (b) to prevent them by active fluid pressure adjustment. The dynamic earthquake events are prevented using high-end, robust stabilizing controllers that stabilize the system even in the absence of knowledge about its friction, elasticity and other complex phenomena that are hard to quantify in practice.Two scenarios are investigated experimentally. In the first scenario, the system is loaded close to its instability point and then fluid is injected in order to provoke a seismic event. We observe how the controller automatically adjusts the fluid pressure in order to prevent such instabilities and immobilize the system. In the second scenario, the controller adjusts the fluid pressure automatically in order to drive the system in a new stable equilibrium of lower energy in an aseismic manner. Despite the inherent unstable behavior of the system, uncertainties related to friction, elasticity and multiphysics couplings, the earthquake-like events are avoided and controlled. We expect our methodology to inspire earthquake mitigation strategies regarding anthropogenic and/or natural seismicity.References[1] Stefanou, I. (2019). Controlling Anthropogenic and Natural Seismicity: Insights From Active Stabilization of the Spring‐Slider Model. Journal of Geophysical Research: Solid Earth, 124(8), 8786–8802. https://doi.org/10.1029/2019JB017847[2] Tzortzopoulos G., Braun P., Stefanou I. (2021), Absorbent Porous Paper Reveals How Earthquakes Could be Mitigated, Geophysical Research Letters 48. https://doi.org/10.1029/2020GL090792.[3] Stefanou, I., Tzortzopoulos, G. (2022). Preventing instabilities and inducing controlled, slow-slip in frictionally unstable systems. Journal of Geophysical Research: Solid Earth. https://doi.org/10.1029/2021JB023410[4] Gutiérrez-Oribio D., Tzortzopoulos G., Stefanou I., Plestan F. (2022). Earthquake Control: An Emerging Application for Robust Control. Theory and Experimental Tests. http://arxiv.org/abs/2203.00296[5] Papachristos, E., Stefanou, I. (2022), Controlling earthquake-like instabilities using artificial intelligence. http://arxiv.org/abs/2104.13180.[6] Gutiérrez-Oribio D., Stefanou I., Plestan F. (2022). Passivity-based Control of a Frictional Underactuated Mechanical System: Application to Earthquake Prevention. https://arxiv.org/abs/2207.07181 Fig.1: Experiments of decametric scale using a novel triplet apparatus for preventing earthquake-like instabilities
Spatio-temporal variability of land surface temperature and vegetation indices within Local Climate Zone classes in Cardiff, Wales
Authors: Sharmin Tania , Lannon Simon , Chappell Adrian
Published: February 2023

This study explores the spatiotemporal variations in Land Surface Temperature (LST) and vegetation indices in relation to Local Climate Zone (LCZ) classification in a coastal, temperate climate city across multiple seasons. The study focuses on Cardiff, the capital and largest city of Wales, located only 2.4 km from the sea. The findings of this study extend our scientific understanding of the interrelations between LST and morphological and surface properties of the built environment and urban vegetation for various LCZ classes in Cardiff. Results showed a significant variation in Surface Urban Heat Island (SUHI) intensity in spring, summer, and winter. LST and Normalised Difference Vegetation Index (NDVI) were found to vary significantly across the LCZ classes demonstrating their association with the local urban form and morphology. For built-up areas, LCZ classes with lower vegetation cover and higher building density showed higher LST. For natural areas, LCZ F (Bare soil or sand) had higher LST than LCZ A (Dense trees). The high-density, built-up LCZ classes have a greater UHI compared to the natural classes. In addition, the results showed that LST and NDVI are significantly affected by the morphological and surface properties for each LCZ classes. Building surface fraction, impervious surface fraction and surface admittance were found to have a positive correlation with LST. Sky View Factor, surface albedo and pervious surface fraction, on the other hand, showed a negative correlation with LST. Opposite associations were found with the NDVI. Urban planners and designers will find the study useful to develop heat mitigation strategies while planning, designing, or improvising the new and existing urban areas in Cardiff. In addition, the LCZ map produced in this study for Cardiff using local expert knowledge will enable international comparison and testing of proven climate change adaptation and mitigation techniques for similar urban areas.
How does the Ionosphere Drive the Magnetospheric Processes?
Authors: Pulkkinen Tuija , Hill Shannon , Brenner Austin , Al Shidi Qusai , Toth Gabor
Published: February 2023

Solar wind – magnetosphere – ionosphere interactions are often interpreted as the solar wind flow and interplanetary magnetic field driving the dynamic processes in the magnetosphere – ionosphere system. However, the atmosphere and the ionosphere host independent dynamic processes, which also influence the magnetospheric dynamics in as yet unquantified ways. In this study, we assess the ability of the global MHD simulations to predict geomagnetic indices, and the role the ionospheric conductance plays in the magnetosphere – ionosphere coupling processes. Specifically, we use the University of Michigan Space Weather Modeling Framework and its Geospace configuration in two different setups: one using the standard Ridley Ionosphere Model (setup similar to that operationally used by the NOAA Space Weather Prediction Center) and another using the  Conductance Model for Extreme Events (CMEE). Comparing the model results for subsolar magnetopause position, AL, Dst, and cross-polar cap potential (CPCP) indices with observed quantities allows us to assess the role of the ionospheric conductance model as well as the overall level of uncertainty within the model as function of the driving intensity. The comparisons are done using a large set of over 80 simulations of geomagnetic storms using both setups.
Joint Generalized Neural Models and Censored Spatial Copulas for Probabilistic Rainfall Forecasting
Authors: Huk David , Adewoyin Rilwan , Dutta Ritabrata
Published: February 2023

This work develops a novel method for generating conditional probabilistic rainfall forecasts with temporal and spatial dependence. A two-step procedure is employed. Firstly, marginal location-specific distributions are modelled independently of one another. Secondly, a spatial dependency structure is learned in order to make these marginal distributions spatially coherent. To learn marginal distributions over rainfall values, we propose a class of models termed Joint Generalised Neural Models (JGNMs). These models expand the linear part of generalised linear models with a deep neural network allowing them to take into account non-linear trends of the data while learning the parameters for a distribution over the outcome space.In order to understand the spatial dependency structure of the data, a model based on censored copulas is presented. It is designed for the particularities of rainfall data and incorporates the spatial aspect into our approach. Uniting our two contributions, namely the JGNM and the Censored Spatial Copulas into a single model, we get a probabilistic model capable of generating possible scenarios on short to long-term timescales, able to be evaluated at any given location, seen or unseen. We show an application of it to a precipitation downscaling problem on a large UK rainfall dataset and compare it to existing methods.
Evaluating effects of topographies on explicit hydromechanical solvers using procedural generation
Authors: Goodwin Saoirse Robin
Published: February 2023

A key problem for landslide research is evaluating hydromechanical solvers on a suitable variety of terrain types. There currently exists a large gulf between studies using hydromechanical solvers on highly idealised terrain, and those on real topographies. This makes it difficult to properly evaluate (i) the sensitivity of the output from the solver to specific terrain features, and (ii) potential numerical artifacts. One way to bridge the gap is to use procedural generation -- which has been used extensively in the videogame and animation industries for three decades -- to generate hillsides with controlled properties. Indeed, the size and frequency of topographical features can be set using procedural generation algorithms, so the spatial distribution of topographical features can be varied in isolation. This study uses a depth-averaged SPH solver to model single-surge flows on a variety of procedurally generated terrains. We investigate the effects of the spatial distribution and magnitude of features on the deposition patterns from the flows. We also discuss other potential applications for these approaches, including hazard mapping for cases where topographical uncertainty is likely (e.g. for modelling snow avalanches).
High-resolution UAV multispectral imagery for water-quality monitoring in coastal regions
Authors: Roman Alejandro , Tovar-Sanchez Antonio , Gauci Adam , Deidun Alan , Caballero Isabel , Colica Emanuele , D'Amico Sebastiano , Heredia Sergio , Navarro Gabriel
Published: February 2023

The concentrations of parameters such as Chlorophyll-a (Chl-a) and Total Suspended Solids (TSS) in seawaters have already been used as indicators of the water quality, the biogeochemical status of surface waters, and nutrient availability. Unmanned Aerial Vehicles (UAVs) have gained global popularity as a remote-sensing tool as they address the optical challenges of water-quality studies in coastal regions. In this work, we evaluate the applicability of a 5-band multispectral sensor mounted on a UAV to derive scientifically valuable water parameters (Chl-a and TSS). The performance of the OC-2 and OC-3 algorithms for Chl-a estimation, as well as the TSS estimation method by Nechad et al. (2010), are tested in two different sites along the Mediterranean coastline. This study provides water quality details on the centimetre-scale and improves the existing approximations that are available for the region through Sentinel-3 OLCI imagery at a much lower spatial resolution of 300 m. The Chl-a and TSS values derived for the studied regions were within the expected ranges and varied between 0 to 3 mg/m3 and 10 to 20 mg/m3, respectively. In addition, a novel Python workflow for the manual generation of an orthomosaic in aquatic areas based on the sensor’s metadata, without the need to resort to commercial photogrammetric software, is proposed. Linear regressions were also applied to compare the Remote Sensing reflectance (Rrs) retrieval methods tested, suggesting strong R2 correlations between 0.83 and 0.91 for the “deglinting” method.
Whistler wave occurrence in the magnetosheath: comparing the quasi-parallel and quasi-perpendicular geometries
Authors: Svenningsson Ida , Yordanova Emiliya , Khotyaintsev Yuri V. , André Mats , Cozzani Giulia
Published: February 2023

​​The Earth’s magnetosheath is a turbulent plasma region where the interplay between coherent structures and various plasma waves affect the particle dynamics and energy transfer. The properties of the magnetosheath are controlled by the upstream conditions. Magnetosheath plasma downstream of a quasi-parallel bow shock (the angle between the shock normal and the interplanetary magnetic field being less than 45°) tends to have stronger fluctuations while a quasi-perpendicular shock leads to a more stationary magnetosheath. These two geometries create different environments for processes such as wave generation. One example is whistler waves that can be excited by non-Maxwellian electron velocity distributions formed in local magnetic structures. Whistler waves have been observed throughout the magnetosheath. As previous statistical studies have considered the region as a whole, it is yet unexplored which magnetosheath geometry creates more favorable conditions for whistler wave generation.In this work, we address this issue and investigate how the occurrence and properties of whistler waves depend on the magnetosheath configuration. We detect whistler waves using data from the Magnetospheric Multiscale (MMS) mission. We compare whistler wave occurrence to the shock normal angle estimated from upstream conditions, as well as local conditions which are typically different between the quasi-parallel and quasi-perpendicular geometries. The results give an indication of the conditions needed for the whistler waves to efficiently dissipate energy in the turbulent magnetosheath.
Probabilistic Assessment of the Causes of Active Deformation in Greece, western Anatolia, and the Balkans Using Spherical Finite Element Models
Authors: Govers Rob , Herman Matthew W. , van de Wiel Lukas , Nijholt Nicolai
Published: February 2023

Plate boundary deformation zones represent a challenge in terms of understanding their underlying geodynamic drivers. Active deformation is well constrained by GNSS observations in the SW Balkans, Greece and W Turkey, and is characterized by variable extension and strike slip in an overall context of slow convergence of the Nubia plate relative to stable Eurasia. Diverse, and all potentially viable, forces and models have been proposed as the cause of the observed surface deformation, e.g., asthenospheric flow, horizontal gravitational stresses (HGSs) from lateral variations in gravitational potential energy, and rollback of regional slab fragments. We use Bayesian inference to constrain the relative contribution of the proposed driving and resistive regional forces. Our models are spherical 2D finite element models representing vertical lithospheric averages. In addition to regional plate boundaries, the models include well-constrained fault zones like north and south branches of the North Anatolian Fault, Gulf of Corinth and faults bounding the Menderes Massif. Boundary conditions represent geodynamic processes: (1) far-field relative plate motions; (2) resistive fault tractions; (3) HGSs mainly from lateral variations in topography and Moho topology; (4) slab pull and trench suction at subduction zones; and (5) active asthenospheric convection. The magnitude of each of these is a parameter in a Bayesian analysis of ~100,000 models and horizontal GNSS velocities. The search yields a probability distribution of all parameter values including model error, allowing us to determine mean/median parameter values, robustly estimate parameter uncertainties, and identify tradeoffs (i.e., parameter covariances). The average viscosity of the overriding plate is well resolved 4x10^22 Pa.s, which is higher than published models without faults. Westward velocities of Anatolia and significant trench suction forces from the Hellenic slab, including along the Pliny-Strabo STEP Fault, are required to reproduce the observations. Slab pull and convective tractions have a small imprint on the observed deformation of the overriding plate. HGSs are less important for fitting the regional pattern of velocities. Resistive tractions on most plate boundaries and faults are low.