bluuebunny/crossref_metadata_2025 huggingface dataset:
Seafloor iron mobilization across the deep-water redox gradients of the Black Sea and the Sea of Marmara
Authors: Alımlı Nimet , Yücel Mustafa
Published: March 2022

Iron is one of the most important redox-sensitive elements in marine systems. A better understanding of the marine iron cycle is urgently needed for many scientific questions, including the evolution of ancient co-factors under changing redox conditions, marine primary production, and global climate change. Given the scarcity of iron in oceans, the interplay between different iron pools in various redox settings is analytically challenging and poorly understood. In this study, we report on new downcore profiles of pore water iron species along with their size distributions across the oxic, suboxic, and sulfidic regions of the Black Sea and in the recently deoxygenated areas of the Sea of Marmara. The vertical distribution of dissolved iron (<0.45 µm) in sediment pore water showed strong subsurface iron peaks reaching maximum concentrations around 87 µM in the Sea of Marmara, resulting in high benthic iron fluxes and indicating high rates of bacterial iron mineral respiration under hypoxia. In the Black Sea, highly sulfidic sediment conditions appeared to limit dissolved iron mobility, with iron concentrations in pore water ranging from 0.3 to 0.05 µM.  We also performed additional experiments at selected sites to understand the nature of the colloidal fraction. Size fractions were obtained by sequential filtering and filtered samples were analyzed by the spectrometric ferrozine method. To achieve the low detection limits required for the water column samples, the spectrometer was used in conjunction with a 50cm liquid waveguide capillary cell, allowing rapid on-board detection of iron at nanomolar levels. The partitioning between soluble (<0.02 µm) and colloidal (0.02-0.2 µm) iron pools in the pore water showed that the dissolved iron was mainly dominated by the soluble fraction, while colloidal fraction behaved differently. The results suggest that the colloidal fraction may be more dependent on other biogeochemical characteristics of the environment in addition to redox conditions. We also applied to colloidal fraction a revised sequential acid leaching scheme originally developed for hydrothermal iron fractions. Preliminary results suggest that the characteristics of the colloidal iron pool in the pore waters of the Sea of Marmara and Black Sea sediments differ from the nanomineral-dominated vent iron, and that organic fractions may play a greater role in mobilizing iron colloids from sediments of deoxygenated basins.  
Identifying sequential characteristics of irradiance data sets applicable for the validation of sets for the assessment of the performance of renewable energy systems containing storage
Authors: Beyer Hans Georg
Published: March 2022

For the analysis of the expected performance of renewable energy systems of all sizes, nowadays various data bases offer the required time series of irradiances and wind speed. The validation of these sets is mainly based on various comparison schemes of averages or distribution functions on a yearly or monthly scale, forming a comprehensive toolbox for the respective quality assessment.  This allows for a high confidence in predictions of system performance data, as-long-as system operation can be considered as “memory-less”.  This is most prominently not the case for systems containing storage devices whose performance depend on the temporal characteristics of the time series - which had been less in focus for the validation of irradiance sets. 

This contribution aims to discuss which sequential characteristics of the data series govern the storage sizing. This should result in the identification of parameters that are applicable for the validation of irradiance series for this task. As example, photovoltaic + battery systems are analyzed, that are driven by data extracted from different sources made available by the PVGIS (https://ec.europa.eu/jrc/en/pvgis ) service.
Electrical properties and anisotropy of schists and fault rocks from New Zealand’s Southern Alps under confining pressure
Authors: Toy Virginia , Kluge Emma-Katherine , Lockner David
Published: March 2022

Magnetotelluric inversions spanning the Pacific-Australian Plate boundary in New Zealand’s South Island indicate there is a localized zone of low electrical resistivity that is spatially co-incident with the mid-crustal part of the Alpine Fault Zone (AFZ), that currently accommodates shear strain by temperature-sensitive creep. We explored the source of this anomaly by measuring the electrical properties of samples collected from surface outcrops approaching the AFZ that have accommodated a gradient of systematic strain and deformation conditions. We investigated the effects of tectonite fabric, fluid saturated pore/fracture networks and grain surface conduction on the bulk electrical response and the anisotropy of resistivity of these samples measured under increasing confining pressures up to 200 MPa. We find that for fault rock protoliths, Haast and Alpine Schist, resistivity and change in anisotropy of resistivity with confining pressure (δ(ρ‖/ρ⊥)/ δ(peff)) increases while porosity decreases approaching the AFZ. This indicates the electrical response is controlled by pore-fluid conductivity and modified during progressive metamorphism. AFZ mylonites exhibit low electrical resistivities at low porosities, and lower δ(ρ‖/ρ⊥)/ δ(peff) than the schists. These reflect changes in both the porosity distribution and electrical charge transport processes in rocks that have experienced progressive grain size reduction and mixing of phases during development of mylonitic fabrics due to creep shear strain within the AFZ.
Modelling coralligenous habitat distribution in the Northern Adriatic Sea in a severe climate change scenario
Authors: Vitelletti Maria Letizia , Manea Elisabetta , Bongiorni Lucia , Bonaldo Davide
Published: March 2022

Climate change drives oceanographic mechanisms at the global level and affects the functioning and structure of marine ecosystems by inducing shifts in species and habitats distribution. The coralligenous outcrops of the Northern Adriatic Sea (Eastern Mediterranean basin) are listed among the habitats of priority for conservation in the Habitats Directive (92/43/EEC) and in the Marine Strategy Framework Directive (2008/56/EC) for their importance as biodiversity hotspots and ecosystem services providers and are recognized to be needy of protection also due to their vulnerability to climate change impacts. This study aims at investigating how environmental variables predicted in future climate change scenarios could affect the distribution and composition of the coralligenous benthic assemblages in the northern Adriatic Sea, to inform management and conservation strategies in the area. A cutting-edge approach was adopted through the application of two predictive models (Maxent and Random Forest) in association with oceanic circulation modeling (ROMS) to deliver the most reliable projections. The present coralligenous habitat distribution and the different habitat typologies (based on the epibenthic assemblages structure inferred from literature) were correlated with historical (consisting in temperature, salinity, velocity, light, nitrogen and phosphorus concentration) and climate change scenario RCP 8.5 (temperature, salinity, velocity) variables in order to provide estimates of possible distribution shifts. Predictive maps showing the degree of habitat suitability across the basin were provided together with a potential shift in the structure of the associated communities. Predictive models are powerful decision-support tools (DSTs) to inform conservation strategies, and in this study they are applied to support the identification of new potential areas of conservation priority in the Northern Adriatic basin, where coralligenous outcrops will be still present in the future despite climate change. We emphasize the relevance of applying DSTs to help undertake science-based actions for conservation purposes in the face of future climate change effects on marine ecosystems.
The Juno Spacecraft Catches a Jupiter Family Comet by the Tail
Authors: Jørgensen John , Jørgensen Peter , Benn Mathias , Andersen Anja , Connerney Jack , Toldbo Christina , Bolton Scott , Levine Steven
Published: March 2022

During cruise from Earth to Jupiter, an attitude-sensing star camera scanned the sky in search of objects large and small. That star camera is part of the Advanced Stellar Compass (ASC), a subsystem of the Magnetometer Investigation charged with providing accurate attitude information at the end of Juno’s magnetometer boom.  The main objective of the cruise observation was to search for smaller, unregistered, solar system objects, but quite unexpectedly the system recorded a great many tiny objects ejected from the spacecraft by the impact of high velocity interplanetary dust particles (IDP). This led to the first ever comprehensive profiling of IDPs from 0.88 to 5.2 AU near the ecliptic plane. We observed a rich IDP population between 1.2AU and the 4:1 mean motion resonance with Jupiter near 2.1AU, and in the Kirkwood gaps, the IDP population drops to near zero beyond the 2:1 mean motion resonance with Jupiter at 3.3AU. However, a hundredfold increase in dust impacts with the spacecraft occurred during a 15-day period in December 2015, shortly before entering the Jovian system. We have identified this event with Juno’s passage through a Jupiter family comet tail. Detailed analysis demonstrates that the comet dust population we observed is characterized by cometary dust particles (CDPs) with a beta in the range of 2-10%. Subdued comet activity far from the Sun frustrates direct observations of the comet tail from Earth; however, our analysis shows that the tail evolution is still dominated by non-gravitational forces acting on particles of a few to tens of micrometers. We present the in-situ comet tail observations and couple these to the complex evolution of comet activity and dust tail dynamics.
Organic, inorganic and total bromine measurements around the extratropical tropopause and lowermost stratosphere
Authors: Rotermund Meike , Engel Andreas , Grooß Jens-Uwe , Hoor Peter , Jesswein Markus , Kluge Flora , Schuck Tanja , Vogel Bärbel , Wagenhäuser Thomas , Weyland Benjamin , Zahn Andreas , Pfeilsticker Klaus
Published: March 2022

We report on measurements of organic, inorganic and total bromine (Brtot) in the upper troposphere and lower stratosphere (UTLS) over southern Argentina and surroundings extending down to the Antarctic Peninsula in September and November of 2019. These measurements were recorded from the German High Altitude and LOng range research aircraft (HALO) as part of the Transport and Composition of the Southern Hemisphere UTLS (SouthTRAC) research campaign. Brtot is inferred from measured total organic bromine (Brorg), i.e., the sum of bromine contained in CH3Br, the halons and the major very short-lived brominated species, added to inorganic bromine (Bryinorg), evaluated from measured BrO and photochemical modelling. Lagrangian transport modelling as well as in situ measured transport (CO and N­­2O) and air mass lag-time (SF6) tracers are used to identify air mass transport pathways into the UTLS and indicate the likely origins of bromine-rich air masses reaching the Southern Hemisphere (SH) lower stratosphere. Additionally, the SH bromine volume mixing ratios are compared with previous measurements from fall 2017 observed in the Northern Hemisphere as part of the Wave-driven ISentropic Exchange (WISE) research campaign, and the long term trend in stratospheric bromine.
Micritization and Microbial-related Diagenetic Features in Modern Shallow Marine Carbonates (Red Sea, Arabian Sea and Arabian Gulf)
Authors: Teillet Thomas , Hachmann Kai , Chandra Viswasanthi , Garuglieri Elisa , Odobel Charlène , Areias Camila , Sánchez-Román Mónica , Vahrenkamp Volker
Published: March 2022

Pores smaller than 10 microns in diameter (microporosity) can make up more than 90% of the total porosity in giant Arabian carbonate reservoirs. While a lot of research has been done to understand the distribution of microporosity, the diagenetic processes initiating its development are still debated. Since microporosity occurs in highly diagenetically overprinted rocks the involvement of early syn-sedimentary processes are generally overlooked. Micritization is a process happening during early diagenesis in the first centimeters of depth in which parts of carbonate grains are reworked to cryptocrystalline textures. The fundamental drivers of micritization are still somewhat debated, however, more and more evidence points to the involvement of microbes such as cyanobacteria, algae, or fungi. So, how can we decipher the diagenetic sequence that ancient limestones have experienced and predict microporosity distribution if the initial steps are poorly understood?

The hypothesis driving this research places microbial micritization as the first step toward the creation of microporosity in limestones. Here, we present the first results undertaken as part of a multidisciplinary research project, at the interface of geology and microbiology and coupling field sampling and laboratory experiments. We compare the rates of micritization and the variety of microbial-related diagenetic features encountered between different carefully selected intertidal locations from the Red Sea and Arabian Sea (Saudi Arabia), and the Arabian Gulf (United Arab Emirates). A series of 1 m long sediment cores has been collected at low tide, and subsamples were extracted from every 10 cm for systematic petrographic and geochemical analyses. Thin section petrography revealed extensive microborings and associated micritization in the sediments. XRD analysis has been carried out to establish the mineral variations through the locations and depth, and SEM imagery further confirmed the presence of organic biofilms and mucous. The results from the metagenomic analysis revealed the microbial diversities and provide further understanding of the specific microbial drivers that play a key role in micritization processes. The work presented here hence aims to enhance the fundamental understanding of micritization in shallow marine carbonate sediment, the role of microbes in early diagenetic processes and their potential impact on microporosity development.
What are the ionospheric and ground magnetic signatures of global magnetopause surface modes?
Authors: Archer Martin , Eggington Joseph , Hartinger Michael , Heyns Michael , Plaschke Ferdinand , Rasaetter Lutz , Shi Xueling , Southwood David , Wright Andrew
Published: March 2022

Surface waves on Earth’s magnetopause act as an efficient mechanism of filtering, accumulating, and guiding the turbulent disturbances present in the solar wind into terrestrial space, thereby playing a key role in controlling global magnetospheric dynamics. However, it is difficult to directly measure these processes since orbiting spacecraft often only provide sparse observation points. It would, therefore, be desirable to be able to remote sense magnetopause surface modes via ionospheric radar or networks of ground magnetometers. The Alfvénic signatures of localised, tailward propagating magnetopause surface waves in ionospheric and ground magnetometer data are somewhat established. However, those associated with the global-scale compressional surface eigenmodes – the lowest frequency and largest-scale normal mode of the magnetospheric system – remain poorly understood. In this presentation we discuss how high-resolution global magnetosphere simulations coupled to an ionosphere model may be able to predict the qualitative features expected in ground-based instruments. Finally, we compare the results of our simulation to simple theory and reported potential observations.
Participatory Development of Storymaps to Illustrate the Spatiotemporal Dynamics and Impacts of Extreme Flood Events
Authors: Munz Lukas , Martius Olivia , Kauzlaric Martina , Mosimann Markus , Fehlmann Anna , Zischg Andreas
Published: March 2022

Investments in flood protection are often made as a reaction to recent events. Flood risk communication and awareness creation might help to raise the motivation for preventive action in flood risk management, rather than implementing reactive measures after an event has occurred. In order to develop a way to convey scientific insight and data on flood risk, together with stakeholders, we are developing an interactive online tool to generate storymaps of local and national extreme flood events. To learn about the needs of every stakeholder, how flood risk information could be communicated and how practitioners can finally apply a resulting tool, we carried out an iterative co-development process. Stakeholders from local emergency intervention forces, insurance companies, cantonal and federal environment offices were interrogated in semi-structured interviews and workshops in an iterative process. The result is an online tool, which allows a user to construct storymaps of extreme flood events by varying several boundary conditions (e.g. duration of the precipitation event, initial conditions, etc.). These storymaps depict how a flood produced by physically plausible storylines of extreme precipitation events evolves and recedes.

With the development of storymaps, we connect physically plausible storylines with dynamical mapping. Both methods address the episodic memory and allow the user to connect new information to personal experiences or the collective memory, and hence create an emotional element. Storylines furthermore allow focusing on single possible realisations of an extreme event rather than an ensemble mean.

The storylines are constructed with the help of a comprehensive model chain: extreme precipitation events (return period >= 100 years) extracted from 8490 years of two merged hindcast archives of ECMWF – ENSext (1998-2017) and SEAS5 (1981-2017) – are used as scenarios to run a hydrological model for the main rivers and lakes in Switzerland. Subsequently, the results of the hydrologic simulations are fed into a hydrodynamic model coupled with an impact module to assess the flood impacts on buildings, roads, and critical facilities such as schools and retirement homes, including the number of affected people. The generated storymaps can be directly used in emergency intervention planning and training, because they provide dynamic information on possible flood impacts in contrast to static hazard maps, which are used for this purpose today. Furthermore, the tool might help to raise flood risk awareness among professionals as well as the interested public by visualizing and localizing physically consistent flood hazard information in an intuitive way.
Investigating the Spatial Extent of Extreme Precipitation
Authors: El Hachem Abbas , Bárdossy András , Seidel Jochen , Goshtasbpour Golbarg , Haberlandt Uwe
Published: March 2022

Investigation of precipitation extremes is traditionally based on point observations. Such rain gauges networks  often have an insufficient network density to  correctly capture the spatial extent of extreme events. An alternative is to use weather radar data which provide a spatially distributed rainfall field but these observations are prone to errors. To reduce the errors in the radar observations, a copula-based merging procedure is applied to combine radar and station observations with high temporal resolution. From this product, the spatial extent of extremes in investigated. This is done by extracting the connected rainfall areas from every rainfall field for several precipitation thresholds and temporal aggregations. The location, size, station data whithin these areas, areal mean precipitation value, and the areal maximum precipitation value are gathered and investigated.

This procedure was applied to the area covered by the German Weather Service (DWD) radar in Hannover with a 5 minutes temporal resolution and for the period 2000-2019. The first results of this investigation shows that station observations underestimate the true areal maxima in most of the cases. Moreover, the connected areas are categorized based on their size and the areal mean precipitation values are compared. It was found that with increasing area size the corresponding areal mean increased. This was observed until a certain area size is reached after which the areal mean almost stabilizes. A clustering of the continuous areas revealed that the occurrence of the areas is independent of the location and that extreme observation can occur anywhere within the study region.
In-situ monitoring of strain on the seafloor: an overview and results of the GeoSEA projects
Authors: Kopp Heidrun , Lange Dietrich , Urlaub Morelia , Petersen Florian , Jegen Anna
Published: March 2022

The ocean floor is the outer solid shell for over 70% of our planet, which is continuously moved and deformed in the course of global plate tectonics. These processes lead to tectonic stresses building up in the seafloor, which over long periods of time become so large that they suddenly and usually (still) unexpectedly discharge in an earthquake. In the marine environment, the seafloor cannot be studied with the established tools of tectonic geodesy, as water is not a suitable medium for geodetic systems that depend on the relatively unperturbed transmission of electromagnetic waves. During the past three decades, advances made by using space geodetic systems, such as GPS and InSAR, have revolutionized our ability to precisely track actively deforming areas onshore in high spatial and temporal resolution. Offshore, seafloor geodesy aims at precise underwater measurements of interstation distances, absolute positions, water depth, and tilt. Seafloor displacement occurs in the horizontal (x,y) and vertical direction (z) as a function of time (t). The vertical displacement is measured by monitoring pressure variations at the seafloor. Horizontal seafloor displacement can be measured either using an acoustic/GPS combination to provide absolute positioning or by long-term acoustic telemetry between different beacons fixed on the seafloor to determine relative distances by using the travel time observations to each other, which is the technique used in the framework of the GeoSEA project (Geodetic Earthquake Observatory on the SEAfloor) with the aim to record deformation directly on the seafloor. Acoustic direct path measurements by the GeoSEA Array were conducted across the North Anatolian Fault in the Sea of Marmara, on the flank of Mt Etna in the Ionian Sea, and on the North-Chilean subduction zone in the eastern Pacific. The goal of these observations is to be able to directly measure the stress buildup and use it to refine estimates of the hazard situation. Since the expected deformation rates are low (a few cm/year at most), the stations have to remain on the seafloor for several years, where they measure autonomously in water depths up to 5,500 m with a precision of 5 mm, allowing for precise measurements of strain build-up in the seafloor. The results from the different campaigns reveal the range and degree of coupling as well as the distribution of deformation, ranging from fully locked to slow-slip movement.
Measuring cloud sensitivity to aerosols at a global scale using isolated aerosol sources
Authors: Gryspeerdt Edward , Louro Coelho Manuel , Smith Tristan , Suarez De La Fuente Santiago , Quilelli Correa Rocha Ribeiro Rodrigo , van Reeuwijk Maarten
Published: March 2022

The sensitivity of clouds to anthropogenic aerosol perturbations remains one of the largest uncertainties in the human forcing of the climate system. A key difficulty is in isolating the impact of aerosols from large-scale covariability of aerosol and cloud properties. Natural experiments, where aerosol is produced independently of the cloud and meteorological properties, provide a pathway to address this issue. These aerosol sources often modify cloud properties, leaving linear cloud features known as shiptracks (when formed by a ship) or pollution tracks (more generally).

In this work, we use a database of point sources of aerosol over both land and ocean to identify clouds that are sensitive to aerosol and to measure their response. Using a neural network to identify when a point source is modifying the cloud, we are able to measure the sensitivity of individual clouds to aerosol at a global scale, looking at over 400 million cases.

We find the probability of track formation is strongly dependent on the background cloud and meteorological state, similar to previous regional studies. With our global database, we identify regions that are strongly susceptible to aerosol perturbations, even where aerosol sources are rare. We find that there are several regions that are highly susceptible to aerosol, but that have been previously overlooked due to a low frequency of pollution tracks.    
New wintertime observations allow re-examination of Southern Ocean carbon sink variability
Authors: Mackay Neill
Published: March 2022

The Southern Ocean accounts for 40% of the uptake of anthropogenic CO2 by the global ocean, which in turn absorbs a quarter of all anthropogenic CO2 emissions, mitigating climate change. Despite its importance, sampling of the Southern Ocean is sparse and biased towards the summer months, and consequentially uncertainties in the carbon sink and its variability are largest there. Recently, autonomous platforms have begun to provide year-round coverage of the parameters needed to estimate the Southern Ocean carbon sink; however, these new observations cannot address the historical sparsity. We present a new estimate of the sink to address historically sparse wintertime sampling through interpretation of subsurface summertime observations to produce new ‘pseudo’ wintertime observations of surface fCO2, boosting the wintertime spatiotemporal coverage by 22% and improving the spatial distribution. We show through a commonly used machine learning technique mapping method, that enhanced wintertime coverage does not significantly alter estimates of the flux or its variability at the sub-basin scale. After adjusting for surface boundary layer temperature effects, we find a strong mean sink south of 35°S of 1.29 ± 0.29 PgC yr-1 for 2004-2018, consistent with recent independent estimates from atmospheric data.
Examining Radial-Interchange in the Jovian Magnetosphere using JERICHO: a Kinetic-Ion, Fluid-Electron Hybrid Model
Authors: Wiggs Joshua , Arridge Chris
Published: March 2022

The Jovian magnetosphere is loaded internally with material from the volcanic moon of Io, which is ionised and brought into co-rotation forming the Io plasma torus. Plasma is removed from the torus mainly via ejection as energetic neutrals and by bulk transport into sink regions in the outer magnetosphere.

There are two physical processes that are implicated in the bulk transport process, these are diffusion and the radial-interchange (RI) instability. The latter is analogous to the Rayleigh-Taylor instability, but with centrifugal force replacing gravity. This allows magnetic flux tubes containing hot, tenuous plasma to exchange places with tubes containing cool, dense plasma, moving material from the inner to outer magnetosphere whilst returning magnetic flux to the planet. Observational data does not currently provide strong evidence to favour either process and indeed they may be non-linearly coupled. Furthermore, current state-of-the-art simulations do not permit an understanding of non-linear phases of the instability nor the effect of magnetosphere-ionosphere coupling on small length scales.

In order to examine the bulk transport process we have developed a full hybrid kinetic ion, fluid-electron plasma model in 2.5-dimensions, JERICHO. The technique of hybrid modelling allows for probing of plasma motions from the scales of planetary-radii down to the ion-inertial length, considering constituent ion species kinetically as charged particles and forming the electrons into a single magnetised fluid continuum. This allows for insights into particle motions on spatial scales below the size of the magnetic flux tubes. We are particularly interested in exploring a) bulk transport on spatial scales not currently accessible with other state-of-the-art models; b) the relative contributions from diffusive motions against those from RI instabilities; and c) non-linear effects generated by RI instabilities and the impact of these on plasma transport from the inner to outer magnetosphere. In this presentation we will examine the latest simulation results from JERICHO, initialised with a range of Jovian parameters, examining the evolution of the RI instability on differing spatial and temporal scales.
Monitoring Relative Surface Soil Moisture Using Sentinel-1 Across the River Thames Catchment
Authors: Maslanka William , Morrison Keith , White Kevin , Verhoef Anne , Clark Joanna
Published: March 2022

Soil moisture is a critical component in many hydrological, agricultural, and meteorological applications and processes, and understanding the spatiotemporal dynamics and changes is critical to further their understanding. They are also an important parameter for use within soil- and land-based Natural Flood Management (NFM) schemes, to determine a relationship between surface wetness and soil water storage. Satellite-based remote sensing offers the ability to capture this spatiotemporal information on soil moisture on the synoptic scale; compared to more site-based in-situ field measurements, made up of numerous national and international soil moisture networks. In this study, we use Sentinel-1 SAR imagery over the course of six water years (from 2016 to 2021), utilizing the TU-Wein change-detection algorithm to calculate the relative Surface Soil Moisture (rSSM) across the River Thames Catchment in Southern England, equating to approximately 11,000 km2. As part of this, two pairs of backscatter normalisation factors were considered, in order to negate the impact from varying local incidence angles: a simple direct-slope and a complex multiple regression slope, both calculated annually and monthly. Whilst the monthly normalisation factor does exhibit a seasonal cycle (attributed to the growth and harvest of arable crops within the study area) in both the simple and multiple regression methodology, the impact upon the rSSM, when compared to the traditional annual method is small. In order to assess the spatiotemporal patterns of soil moisture across the River Thames Catchment, the rSSM timeseries was calculated using multiple spatial scales (1km, 500m, 250m, and 100m), to effectively estimate the rSSM across the catchment, sub-catchment, inter-field, and intra-field spatial scales. Comparisons with the Cosmic-ray Soil Moisture Observing System, United Kingdom (COSMOS-UK), show that, although there is an overestimation in rSSM over the summer months during the growing season of Arable farmland, we were able to effectively capture the general temporal dynamics of the relative Surface Soil Moisture across the region, with an average uncertainty of 30%, across both pairs of backscatter normalisation factors, and across all four spatial scales. Having catchment-wide datasets of rSSM such as this would be advantageous for evaluating land- and soil-based NFM measures across catchment and sub-catchment scales and have the potential for further application to improve hydrological model outputs.
Reconnection and Turbulence: A Qualitative Approach to their Relationship
Authors: Adhikari Subash , Shay Michael A. , Parashar Tulasi N. , Matthaeus William H. , Sharma Pyakurel Prayash , Stawarz Julia E. , Eastwood Jonathan P.
Published: March 2022

Over the past few decades, the relationship between turbulence and reconnection has emerged as a subject of interest. For example, various properties of reconnection have been studied in different turbulent environments using plasma simulations. In other approaches, reconnection is studied as a subsidiary process occurring in turbulence. Turbulent features are also studied as consequences of instabilities associated with large scale reconnection. Only recently, we have attempted to answer some of the fundamental questions such as: “What are the turbulent-like features of laminar magnetic reconnection?”, "Is magnetic reconnection fundamentally an energy cascade?" both related to the interplay between reconnection and turbulence. Using 2.5D particle in cell simulations, we have found that laminar magnetic reconnection in a quasi-steady phase exhibits a Kolmogorov-like power spectrum. Most notably, the energy transfer process in magnetic reconnection is also found to be similar to that of a turbulent system suggesting that reconnection involves an energy cascade. The reconnection rate is correlated to both the magnetic energy spectrum in the ion-scales and the cascade of energy. Further, similarities between reconnection and turbulence in terms of the electric field spectrum, their components, and pressure-strain interaction will be highlighted.
Multi-temporal landslide inventory for validation of landslide susceptibility maps after 2018 Vaia windstorm event in Belluno province (Veneto Region, NE, Italy). 
Authors: Meena Sansar Raj , Puliero Silvia , Bhuyan Kushanav , Nava Lorenzo , Faes Lorenzo , Floris Mario , Catani Filippo , Lingua Emanuele
Published: March 2022

Landslide susceptibility maps are often not validated after significant landslide events. In this work, we analyse the impact of the Vaia windstorm on landslide activity in Belluno province (Veneto Region, NE, Italy). The storm hit the area on October 27-30, 2018, causing 8,679 ha of damaged forests and widespread landslides. As shown in the case of windstorm Vivian (1990) and Lothar (1999) (Switzerland), extreme meteorological events can influence slope stability after three to ten years (Bebi et al 2019). Through multi-temporal landslide inventory mapping post Vaia event, we want to access and validate the landslide susceptibility maps produced by using pre-event data from the Italian Landslide Inventory IFFI and assess if the susceptibility has increased in the areas affected by the storm. We used artificial intelligence techniques to prepare multi-temporal inventory and susceptibility maps pre and post-event. In the pre-event event inventory, 5934 landslides and 14 landslide conditioning factors were used to prepare the susceptibility models. We then validate the pre-event landslide susceptibility maps using post-event inventory from the 2018 Vaia windstorm and a following intense rainfall event that occurred in the same area in December 2020. A total of 542 landslides were mapped after the 2018 Vaia storm event, and an update to the landcover map as forest damage layer was used for post-event susceptibility analysis. This study is one of the first attempts to validate pre-event susceptibility maps by utilising multi-temporal artificial intelligence-based landslide inventories in Belluno province (Veneto Region, NE, Italy).

 

Bebi, P., Bast, A., Ginzler, C., Rickli, C., Schöngrundner, K., and Graf, F., 2019, Forest dynamics and shallow landslides: A large-scale GIS-analysis: Schweizerische Zeitschrift fur Forstwesen, v. 170, p. 318–325, doi:10.3188/szf.2019.0318.
Exploring the relationship between S2S temperature forecasting errors and Earth system variables
Authors: Ruiz-Vásquez Melissa , Oh Sungmin , Brenning Alexander , Balsamo Gianpaolo , Weber Ulrich , Reichstein Markus , Koster Randal , Orth René
Published: March 2022

Accurate weather forecasts can help to reduce costs and impacts related to weather and corresponding extremes. The quality of weather forecasts has improved considerably in recent decades as models are representing more physical processes, and can increasingly benefit from assimilating comprehensive Earth observation data. However, this increased complexity presents a challenge for pinpointing weaknesses in the forecast models’ process representations, which is needed to support continuous improvement in forecast accuracy.

In this study, we use a comprehensive set of observation-based ecological, hydrological and meteorological variables to study their potential for explaining temperature forecast errors at the weekly time scale. For this purpose, we computed Spearman correlations between each considered variable and the forecast error obtained from the ECMWF S2S re-forecasts dataset with lead times between 1 and 6 weeks. This is done across the globe for the time period 2001-2017. The results suggest that circulation-related variables such as wind speed and spatial pressure differences are overall most strongly related to forecast errors across the globe, suggesting that an improved representation of the large-scale circulation in the forecast model has the greatest potential to improve temperature forecasts. At the same time we found particular regions and seasons in which other variables are more strongly related to forecast errors, for  instance: i) during the growing season in Central Europe, Central Africa and Northern South America, the vegetation greenness and soil moisture are relevant, and ii) meteorological variables such as solar radiation, precipitation and sea surface temperature are relevant in Asia and Eastern Europe during boreal summer and autumn. Additionally, we found that the actual values of the variables are generally more strongly related to the forecast errors than their anomalies, pointing towards a systematic nature of the errors. Towards longer lead times, in contrast, the relevance of anomalies increases while correlations with the absolute values decrease. This highlights that biophysical information beyond the mean seasonal cycle can be informative for temperature forecasts. 

Our identification of variables related to forecast errors can inform the development of forecast models and data assimilation schemes, considering that most of the highlighted variables have corresponding satellite datasets available in near-real-time on a global scale.
hydroMOPSO: A versatile Particle Swarm Optimization R package for multi-objective calibration of environmental and hydrological models
Authors: Marinao-Rivas Rodrigo , Zambrano-Bigiarini Mauricio
Published: March 2022

In this work we introduce hydroMOPSO, a novel multi-objective R package that combines two search mechanisms to maintain diversity of the population and accelerate its convergence towards the Pareto-optimal set: Particle Swarm Optimisation (PSO) and genetic operations. hydroMOPSO is model-independent, which allows to interface any model code with the calibration engine, including models available in R (e.g., TUWmodel, airGR, topmodel), but also any other complex models that can be run from the system console (e.g. SWAT+, Raven, WEAP). In addition, hydroMOPSO is platform-independent, which allows it to run on GNU/Linux, Mac OSX and Windows systems, among others.

Considering the long execution time of some real-world models, we used three benchmark functions to search for a configuration that allows to reach the Pareto-optimal front with a low number of model evaluations, analysing different combinations of: i) the swarm size in PSO, ii) the maximum number of particles in the external archive, and iii) the maximum number of genetic operations in the external archive. In addition, the previous configuration was then evaluated against other state-of-the-art multi-objective optimisation algorithms (MMOPSO, NSGA-II, NSGA-III). Finally, hydroMOPSO was used to calibrate a GR4J-CemaNeige hydrological model implemented in the Raven modelling framework (http://raven.uwaterloo.ca), using two goodness-of-fit functions: i) the modified Kling-Gupta efficiency (KGE') and ii) the Nash-Sutcliffe efficiency with inverted flows (iNSE).

Our results showed that the configuration selected for hydroMOPSO makes it very competitive or even superior against MMOPSO, NSGA-II and NSGA- III in terms of the number of function evaluations required to achieve stabilisation in the Pareto front, and also showed some advantages of using a compromise solution instead of a single-objective one for the estimation of hydrological model parameters.
Volcano hazard monitoring using remote sensing techniques during the Cumbre Vieja volcano 2021 eruptive crisis
Authors: Ganci Gaetana , Bilotta Giuseppe , Calvari Sonia , Cappello Annalisa , D'Auria Luca , Hernández Pedro , Pérez Nemesio M. , Spampinato Letizia
Published: March 2022

On 19 September 2021, after about 50 years of quiescence, a new eruption started at Cumbre Vieja volcano (Canarias, Spain). The onset was preceded by a series of seismic swarms, the last one of which occurred on 11 September 2021. A system of eruptive fissures opened and multiple vents produced lava fountains, sustained ash columns, and lava flows that travelled over 5 km W to the sea, damaging hundreds of properties along their path. The eruption forced the evacuation of over 7,000 people and destroyed nearly 3,000 buildings, ending on 13 December, after 85 days.

We here detail the different phases of the eruption and describe and discuss the lava flow field structures and emplacement dynamics by using ground- and air-based thermal camera data as well as using multispectral satellite images. Indeed, the high temporal resolution of SEVIRI images - i.e. an image every 15 minutes - allowed tracking the lava flow development and provided an estimation of the effusion rate. Sentinel 2, Landsat 8 and PlanetScope images enabled mapping the active areas of the lava field and, thus to clearly depict the formation of lava tube systems promoting lava flow lengthening to the sea. Moreover, the satellite-derived data were used as input to the GPUFLOW model to produce near real time, short-term lava flow hazard maps.
High-resolution spatial-distribution maps of road transport exhaust emissions in Chile, 1990–2020
Authors: Osses Mauricio , Rojas Néstor , Ibarra Cecilia , Valdebenito Víctor , Laengle Ignacio , Pantoja Nicolás , Osses Darío , Basoa Kevin , Tolvett Sebastián , Huneeus Nicolás , Gallardo Laura , Gómez Benjamín
Published: March 2022

Abstract. This description paper presents a detailed and consistent estimate and
analysis of exhaust pollutant emissions generated by Chile's
road transport activity for the period 1990–2020. The complete database for
the period 1990–2020 is available at the following DOI:
https://doi.org/10.17632/z69m8xm843.2 (Osses et al., 2021). Emissions are
provided at a high spatial resolution (0.01∘ × 0.01∘) over continental Chile from 18.5 to 53.2∘ S,
including local pollutants (CO; volatile organic compounds, VOCs; NOx; PM2.5), black carbon (BC) and
greenhouse gases (CO2, CH4). The methodology considers 70 vehicle
types, based on 10 vehicle categories, subdivided into 2 fuel types and
7 emission standards. Vehicle activity was calculated based on official
databases of vehicle records and vehicle flow counts. Fuel consumption was
calculated based on vehicle activity and contrasted with fuel sales to
calibrate the initial dataset. Emission factors come mainly from the Computer programme to calculate emissions from road
transport version 5 (COPERT 5),
adapted to local conditions in the 15 political regions of Chile, based on
emission standards and fuel quality. While vehicle fleet grew 5-fold
between 1990 and 2020, CO2 emissions have followed this trend at a
lower rate, and emissions of air local pollutants have decreased due to
stricter abatement technologies, better fuel quality and enforcement of
emission standards. In other words, there has been decoupling between fleet
growth and emissions' rate of change. Results were contrasted with global
datasets (EDGAR, CAMS, CEDS), showing similarities in CO2 estimations
and striking differences in PM, BC and CO; in the case of NOx and CH4
there is coincidence only until 2008. In all cases of divergent results,
global datasets estimate higher emissions.
Rockfall trajectory reconstruction: A flexible method utilizing video footage and high-resolution terrain models
Authors: Noël François , Jaboyedoff Michel , Caviezel Andrin , Hibert Clément , Bourrier Franck , Malet Jean-Philippe
Published: March 2022

Abstract. Many rockfall simulation software provide great flexibility to the user at the expense of a hardly achievable parameter unification. With sensitive site-dependent parameters that are hardly generalizable from the literature and case studies, the user must properly calibrate simulations for the desired site by performing back calculation analyses. Thus, rockfall trajectory reconstruction methods are needed. For that purpose, a computer-assisted videogrammetric 3D trajectory reconstruction method (CAVR) built on earlier approaches is proposed. Rockfall impacts are visually identified and timed from video footage, and are manually transposed on detailed high-resolution 3D terrain models that act as the spatial reference. This shift of reference removes the dependency on steady and precisely positioned cameras, ensuring that the CAVR method can be used for reconstructing trajectories from witnessed previous records with nonoptimal video footage. For validation, the method is applied to reconstruct some trajectories from a rockfall experiment performed by the WSL Institute for Snow and Avalanche Research SLF. The results are compared to previous ones from the SLF and share many similarities. Indeed, the translational energies, bounce heights, rotational energies and impact positions against a flexible barrier compare well with those from the SLF. Interestingly, only dissipative impact processes are observed with the CAVR method, contrary to the previous results from the SLF. The comparison shows that the presented cost-effective and flexible CAVR method can reproduce proper 3D rockfall trajectories from experiments or real rockfall events.
Improved double Fourier series on a sphere and its application to a semi-implicit semi-Lagrangian shallow-water model
Authors: Yoshimura Hiromasa
Published: March 2022

Abstract. One way to reduce the computational cost of a spectral
model using spherical harmonics (SH) is to use double Fourier series (DFS)
instead of SH. The transform method using SH usually requires
O(N3) operations, where N is the truncation
wavenumber, and the computational cost significantly increases at high
resolution. On the other hand, the method using DFS requires only
O(N2log N) operations. This paper proposes a new
DFS method that improves the numerical stability of the model compared with
the conventional DFS methods by adopting the following two improvements: a
new expansion method that employs the least-squares method (or the Galerkin
method) to calculate the expansion coefficients in order to minimize the
error caused by wavenumber truncation, and new basis functions that satisfy
the continuity of both scalar and vector variables at the poles. Partial
differential equations such as the Poisson equation and the Helmholtz
equation are solved by using the Galerkin method. In the semi-implicit
semi-Lagrangian shallow-water model using the new DFS method, the Williamson
test cases and the Galewsky test case give stable results without the
appearance of high-wavenumber noise near the poles, even without horizontal
diffusion and without a zonal Fourier filter. In the Eulerian advection
model using the new DFS method, the Williamson test case 1, which simulates
a cosine bell advection, also gives stable results without horizontal
diffusion but with a zonal Fourier filter. The shallow-water model using the
new DFS method is faster than that using SH, especially at high resolutions
and gives almost the same results, except that very small oscillations near
the truncation wavenumber in the kinetic energy spectrum appear only in the
shallow-water model using SH.