bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal variability of energy transport in the Black Sea for the basin-scale and eddy circulation regimes
Authors: Dymova Olga , Demyshev Sergey
Published: March 2022

The aim of this work is to study the seasonal variability of the mean current kinetic energy MKE, the eddy kinetic energy EKE, the mean available potential energy MPE, the eddy available potential energy EPE, and the rates of energy conversion for basin-scale and eddy circulation regimes in the Black Sea. The basin-scale circulation is a regime when the entire basin is covered by the cyclonic Main Black Sea Current (the Rim Current), which spread over the continental slope. The eddy circulation is a regime when the Rim Current is partially or completely destroyed and intense mesoscale eddies evolve in the abyssal part of the sea. Monthly energy characteristics are calculated based on eddy-resolving simulation data derived under atmospheric forcing SKIRON. Analysis of the reconstructed current fields showed that the basin-scale and the eddy circulation regime are realized in 2011 and in 2016, respectively.

Seasonal signal is weakly manifested in the variability of the MKE; its value depends on the wind forcing and current velocities, which are higher in the basin-scale circulation regime. The distribution of the MPE is predominantly seasonal; temporal variability is qualitatively similar for both regimes and is caused by increase in the density anomaly due to warming up of seawater. The energy transport MPE→MKE due to the buoyancy work is provided in the subsurface layer for all seasons and the Cold Intermediate Layer for the warm seasons in both regimes.

Seasonal variability of the EKE and the mechanisms of its intensification are different for two circulation regimes. The EKE is maximal in spring and summer in the basin-scale circulation regime, and in the cold season in the eddy circulation regime. In winter, when the Rim Current or its elements are most intense, irrespective of the circulation regime, the mesoscale eddies develop mainly due to energy transport MKE→EKE via barotropic instability mechanism. In summer, the mesoscale variability in the basin-scale circulation regime is due to commensurate contributions of barotropic and baroclinic instability, and in the eddy circulation regime only by the energy transport MPE→EKE due to baroclinic instability.

The reported study was funded by the Marine Hydrophysical Institute state task No. 0555-2021-0004.
Southern Ocean Carbon and Heat Impact on Climate (SOCHIC): processes and long term change
Authors: Sallée Jean-Baptiste
Published: March 2022

The Southern Ocean regulates the global climate by controlling heat and carbon exchanges between the atmosphere and the ocean. Rates of climate change on decadal time scales ultimately depend on oceanic processes taking place in the Southern Ocean, yet too little is known about the underlying processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent small-scale processes that are not captured in current Earth system models. We address some of these limitations in the european consortium Southern Ocean Carbon and Heat Impact on Climate (SO-CHIC). In this talk, I will present an overview of the important advances we made in the first two years of the consortium, ranging from (i) new understanding of small-scale transcient processes, such as ocean (sub)mescale or atmopsheric storms, impact on upper ocean ventilation and air-sea fluxes, to (ii) long term change in Southern Ocean structure, from the surface to the abysses, and via (iii) investigation of processes controling Maud Rise polynya events, decadal variability of heat and carbon storage, and large-scale atmospheric feedback. 
Spectral formulation of the 3D elastodynamic boundary integral equations for a bi-material interface
Authors: Gupta Avinash , Kunnath Ranjith
Published: March 2022

We present a numerical scheme to study 3D fracture problems at a planar interface. This scheme is based on the spectral representation of the boundary integral equation method which involves the evaluation of elastodynamic convolutions at the interface. The advantage of this method is that it is numerically efficient as it calculates the field quantities only on the fracture plane rather than in the entire domain. In the current approach, spatial convolution is replaced by multiplication in the spectral domain which increase the computational efficiency. In the literature, Geubelle and Rice [1995] first introduced the 3D spectral representation of the formulation of Budiansky and Rice [1979]. In their approach, the time-convolution is performed of the displacement history at the interface. Later, 3D formulation for a bi-material interface was proposed by Breitenfeld and Geubelle [1998]. Recently, a spectral form of the Kostrov [1966] was proposed by Ranjith [2015] for 2D in-plane problems. In this approach, time-convolution is performed of the traction history at the interface. An advantage of this approach is that the convolution kernels for a bi-material interface can be expressed in closed form, whereas Breitenfeld and Geubelle [1998] had to obtain their convolution kernels numerically. In the present work, convolution kernels for 3D elastodynamic fracture problems at a bi-material interface are derived following the approach of Ranjith [2015].
Diagnosing the thickness-weighted averaged eddy-mean flow interaction from an eddying North Atlantic ensemble
Authors: Uchida Takaya , Jamet Quentin , Dewar William , Le Sommer Julien , Penduff Thierry , Balwada Dhruv
Published: March 2022

The analysis of eddy-mean flow interaction provides key insights into the structures and dynamics of inhomogeneous and anisotropic flows such as atmospheric and oceanic jets. As the divergence of Eliassen-Palm (E-P) flux formally encapsulates the interaction, the community has had a long-standing interest in accurately diagnosing this term. Here, we revisit the E-P flux divergence with an emphasis on the Gulf Stream, using a 48-member, eddy-rich (1/12°) ensemble of the North Atlantic ocean partially coupled to identical atmospheric states amongst all members via an atmospheric boundary layer model. This dataset allows for an unique decomposition where we define the mean flow as the ensemble mean, and interpret it as the oceanic response to the atmospheric state. The eddies are subsequently defined as fluctuations about the ensemble mean. Our results highlight two points: i) the implementation of the Thickness-Weighted Averaged (TWA) framework for a realistic ocean simulation in diagnosing the E-P flux divergence, and ii) validity of the ergodic assumption where one treats the temporal mean equivalent to the ensemble mean, which is questionable for a temporally varying system such as the ocean and climate.
Effect of Gravity Data Coverage on the Gravity Field Recovery: Case Study for Egypt (Africa) and Austria
Authors: Abd-Elmotaal Hussein , Kühtreiber Norbert
Published: March 2022

The coverage of the gravity data plays an important role in the geoid determination. This paper tries to answer whether different geoid determination techniques would be affected similarly by such gravity data coverage. The paper presents the determination of the gravimetric geoid in two different countries where the gravity coverage is quite different. Egypt (representing the same situation in Africa) has sparse gravity data coverage over relatively large area, while Austria has quite dense gravity coverage in a significantly smaller area. Two different geoid determination techniques are tested. They are Stokes’ integral with modified Stokes kernel, for better combination of the gravity field wavelengths, and the least-squares collocation technique. The geoid determination has been performed within the framework of the non-ambiguous window remove-restore technique (Abd-Elmotaal and Kühtreiber, 2003). For Stokes’ geoid determination technique, the Meissl (1971) modified kernel has been used with numerical tests to obtain the best cap size for both geoids in Egypt and Austria. For the least-squares collocation technique, a modelled covariance function is needed. The Tscherning-Rapp (Tscherning and Rapp, 1974) covariance function model has been used after being fitted to the empirically determined covariance function. The paper gives a smart method for such covariance function fitting. All geoids are fitted to GNSS/levelling geoids for both countries. For each country, the computed two geoids are compared and the correlation between their differences versus the gravity coverage is comprehensively discussed.
Multi-taxa eDNA metabarcoding to monitor the degradation and restoration of belowground biota in agricultural soils
Authors: Donald Julian , Wills Jane , Early Regan , Chave Jerome , Iribar Amaia , Murienne Jerome , Zinger Lucie , Gonzales Mailyn
Published: March 2022

Land use change drives shifts in the taxonomic and functional diversity of soil organisms. Soil biota response will depend on both local scale agricultural management, and regional scale environmental conditions, with the diverse pool of soil taxa unlikely to respond in a uniform manner. To monitor the effect of land management and potential restoration efforts, we require techniques which can be deployed at various spatial scales, and which account for the high diversity of these communities. In this presentation, we describe the role of eDNA metabarcoding targeting a broad range of taxa to detect and parameterise these responses. We present the results of studies of habitat conversion of humid and dry forests in French Guiana and Colombia respectively, before detailing how the method will be used to monitor agricultural pasture in the UK undergoing conversion to “regenerative” management. In these studies, we combine measures of alpha and beta diversity to account for shifts in species abundance dependent on habitat management, and assignment of functional groups to infer shifts in soil biota functioning.  Overall, we find that results track expected shifts in biota, for example a replacement of a broad diversity of plant eDNA to a community signal largely dominated by grasses. Agricultural soils are characterised by a greater proportion of bacteria and protists associated with the cycling of labile nitrogen. We conclude by pointing to the weaknesses of the method, and highlighting the importance of complimentary methods in spite of fruitful deployment across varied habitats.
Effects of heterogeneous reaction with NO2 on ice nucleation activities of feldspar and Arizona Test Dust
Authors: Chen Lanxiadi , Peng Chao , Chen Jingchuan , Chen Jie , Wu Zhijun , Tang Mingjin
Published: March 2022

Mineral dust is an important type of ice nucleating particles in the troposphere; however, the effects of heterogeneous reactions on ice nucleation (IN) activities of mineral dust remain to be elucidated. A droplet-freezing apparatus (Guangzhou Institute of Geochemistry Ice Nucleation Apparatus, GIGINA) was developed in this work to measure IN activities of atmospheric particles in the immersion freezing mode, and its performance was validated by a series of experimental characterizations. This apparatus was then employed to measure IN activities of feldspar and Arizona Test Dust (ATD) particles before and after heterogeneous reaction with NO2 (10±0.5 ppmv) at 40% relative humidity. The fractional surface coverage of nitrate, θ(NO3-), increased to 3.1±0.2 for feldspar after reaction with NO2 for 6 h, and meanwhile the active site density per unit surface area (ns) at -20 oC was reduced from 92±5 to <1.0cm-2 by about two orders of magnitude; however, no changes in nitrate content or IN activities were observed for further increase in reaction time (up to 24 h). Both nitrate content and IN activities changed continuously with reaction time (up to 24 h) for ATD particles; after reaction with NO2 for 24 h, θ(NO3-) increased to 1.4±0.1 and ns at -20 oC was reduced from 20±4 to 9.7±1.9 cm-2 by a factor of ~2. Our work suggests that heterogeneous reaction with NO2 may significantly reduce IN activities of mineral dust in the immersion freezing mode.
Have there been previous heat extremes greater than the June 2021 western North America event? 
Authors: Thompson Vikki , Kennedy-Asser Alan , Lo Eunice , Vosper Emily , Mitchell Dann , Andrews Oliver
Published: March 2022

In June 2021 western North America experienced a record-breaking heatwave, outside the distribution of previously observed temperatures. Our research asks whether other regions across the world have experienced so far outside their natural variability - and have there been greater heat extremes.  

In our novel assessment of heat extremes we characterise the relative intensity of an event as the number of standard deviations from the mean, finding the western North America heatwave is remarkable, outside four single deviations. Throughout the globe, where we have reliable data, only 5 other heatwaves were found to be more extreme since 1960. We can also identify regions which, by chance, have not had a recent extreme heatwave, and may be less prepared for future events. 

Using extreme value analysis the western North America heat extreme has been shown to be outside the previous distribution of extremes for the region. We can test if this is unique, or if previous events show similar. 

By assessing the numbers of regions globally exceeding various thresholds, in terms of standard deviation from the mean, we can show that extremes appear to increase in line with changes to the mean-state of the distribution of the climate, and projected increase in extremes aligns with projected warming.   
Imaging the magnetosphere with the SMILE Mission
Authors: Escoubet C.-Philippe , Wang Chi , Branduardi-Raymont Graziella ,   SMILE team
Published: March 2022

The interaction between the solar wind and the Earth's magnetosphere, and the geospace dynamics that result, is one of the key questions in space plasma physics. In situ instruments on a fleet of solar wind and magnetospheric constellation missions now provide the most detailed observations of Sun-Earth connections over multiple scales, from the smallest of a few kilometres up to the largest of a few 10s of Earth radii. However, we are still unable to quantify the global effects of the drivers of such connections, including the conditions that prevail throughout geospace. This information is the key missing link for developing a complete understanding of how the Sun gives rise to and controls Earth's plasma environment and space weather. This is where SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) comes in.
SMILE is a novel self-standing mission dedicated to observing the solar wind - magnetosphere coupling via simultaneous in situ solar wind/magnetosheath plasma and magnetic field measurements, soft X-ray imaging of the magnetosheath, magnetopause and polar cusps, and UV imaging of the Northern hemisphere auroral oval. Remote sensing of the magnetosheath and cusps with soft X-ray imaging is made possible thanks to solar wind charge exchange (SWCX) X-ray emissions known to occur in the vicinity of the Earth's magnetosphere. SMILE is a joint mission between ESA and the Chinese Academy of Sciences (CAS) due for launch at the end of 2024. SMILE science objectives as well as the latest technical developments jointly undertaken by ESA and CAS and the international instrument teams will be presented.
Water availability assessment for run-of-river hydropower under future climate change in the UK and Ireland
Authors: Dallison Richard , Patil Sopan
Published: March 2022

In the United Kingdom (UK), the amount of electricity generated from small-scale hydropower has nearly tripled since 2010. One of the key areas of growth within the sector has been run-of-river hydropower schemes, with several hundred now operating across the UK and the Republic of Ireland (RoI), the majority situated in mountainous areas of Scotland and Wales. Although the overall grid contribution of these schemes is small (~2%), they still play an important role, not only in decarbonising the grid and contributing to national emission reduction goals, but also at local scales, where schemes often provide financial benefit to local communities and individuals. However, future climate change threatens to alter precipitation patterns and therefore streamflows, potentially impacting both the timing of hydropower generation and the total power output potential.

In this study, we quantify the impact of a worst-case future climate change scenario (Representative Concentration Pathway 8.5) on the generation potential of run-of-river hydropower schemes in the UK and RoI. EXP-HYDRO hydrological model is used to simulate future daily streamflow for the 2021-2080 hydrological years in 178 catchments containing 531 hydropower abstractions. We estimate daily abstraction potential at each site based on the local environmental regulators’ (for Scotland, England, Wales, Northern Ireland, and Ireland) general abstraction conditions. We then perform seasonal and annual Mann-Kendall trend analysis at each site to analyse changes in: 1) the number of days when abstraction is possible, 2) the number of days when maximum abstraction is reached, 3) mean abstraction volume on days when abstraction is possible, and 4) the total abstractable volume. The scale of study undertaken allows for characterisation of both the impact of regional variation in future climate forcing, as well as analysis of the impact of local environmental regulation, on the future generation potential of run-of-river hydropower in the UK and RoI.

Results show increasing annual total abstraction potential in northern England and Scotland, while a decline is seen in Wales; little change is seen in Ireland and Northern Ireland. The number of days per year that abstraction is possible declines in all areas except the northwest of Scotland, while the number of days that maximum allowable abstraction is reached increases; mean daily abstraction therefore increases. A disparity can be seen in different nations between the magnitude, and in some cases direction, of change in annual mean streamflows compared to annual abstraction potential. This is likely caused by differences in water abstraction regulations between UK nations. This poses an interesting question in terms of the impact of environmental regulations for the different nations of the UK, and how best to maximise renewable energy output by hydropower, while protecting the natural environment.
Insights into the evolution of mass flow dynamics from the seismic analysis of the 18 March 2007 Mt. Ruapehu, New Zealand lake-breakout lahar
Authors: Walsh Braden , Procter Jon , Williams-Jones Glyn , Lormand Charline
Published: March 2022

At 23:18 UTC on 18 March 2007 Mt. Ruapehu produced the biggest lahar in New Zealand in over 100 years when a tephra dam holding crater lake water back collapsed causing 1.3x106 m3 of water to flow out and rush down the Whangaehu channel. The outburst of water transformed into a hyperconcentrated streamflow, which traveled more then 200 km from source finally flowing into the Tasman Sea on the West coast of New Zealand. Here, we describe the seismic signature of the lake-breakout lahar over the course of 83 km along the Whangaehu river system using three 3-component broadband seismometers installed <10 m from the channel at distances of 7.4, 28, and 83 km from the crater lake source. Examination of 3-component seismic amplitudes, peak spectral frequency, and directionality combined with video imagery and sediment concentration data depicts the evolution of an ever transforming lahar from a highly turbulent out-burst flood (high peak frequency throughout), to a fully bulked up multi-phase hyperconcentrated flow (varying frequency patterns depending on the lahar phase) to a slurry flow (bedload dominant). Estimated directionality ratios show the elongation of the lahar with distance from source and extraordinary promise for mass flow monitoring and detection systems where streamflow is already present. Ultimately, the 3-component broadband seismic data for the 18 March 2007 lahar at Mt. Ruapehu may lead to more accurate and advanced real-time waring systems for mass flows through the use of seismic frequency and directionality analysis worldwide.
Particle size fraction effects on MIR-DRIFTS: Improving the quantification of sub-basin spatial sediment provenance fingerprinting
Authors: Nosrati Kazem , Fiener Peter
Published: March 2022

There is a growing interest to understand the sources of sediments in river channels as basis for potential mitigation aiming to reduce soil erosion and sediment delivery in larger catchments. Within the last decades, sediment fingerprinting has been established as a powerful tool to unravel the sources of sediments in larger catchments. However, most sediment fingerprinting techniques are based on time-consuming and costly chemical analysis of sediment samples from river channels and sub- catchments. Recent studies have shown the potential of diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) as a rapid, cost-effective, and nondestructive tracers for sediment fingerprinting. The aim of this study is to analyses the sensitivity of DRIFTS based sediment fingerprinting against particle size of sediment tracers and to determine the potential of using multi-size approaches.  We used mid-infrared spectroscopy (MIRS; 4000-600 cm-1) to analyze four size fractions (125-250, 63-125, 63-38, and <38 µm) of 54 sediment samples collected at three different sub-basins spatial sediment sources and 26 target sediment samples collected at the outlet of the main basin of the Andajrood drainage river basin in Iran.  The spectral resolution was averaged over 32 cm-1 intervals to reduce the continues wavelength data to a defined number of spectral bands (n = 104) that is practicable and realistic for a statistical analysis of differences. A one-way ANOVA was used to evaluate the presence of significant contrasts between the content of individual MIRS spectra in the different size fractions. The results showed that MIRS spectra were present and distributed across all size fractions. The results of one-way ANOVA indicated that in sub-basin both, MIRS spectra form spatial sediment sources and target sediment samples, were significantly affected by the particle size fractions. Thus, this confirmed that it was appropriate to identify the dominant particle size fraction in the sediment samples and to confirm that MIRS spectra were present across that fraction rather than a sub-fraction.
Fly ash releases from surface impoundments can be identified through spICP-TOF-MS fingerprinting
Authors: Schüürman Jan , Micić Vesna , von der Kammer Frank , Hofmann Thilo
Published: March 2022

Coal fly ash is used in the construction industry and holds potential as a resource for the extraction of rare earth elements and high-value metals such as scandium. It is commonly stored in uncovered landfills or ash ponds close to the coal-fired power stations. Major releases from these surface impoundments into adjacent rivers pose an environmental concern due to the harmful effects of associated heavy metals. Future releases may occur more frequently as the globally impounded ash volume continues to grow and climate change threatens to further increase extreme rainfall events, which can cause overflows of surface impoundments and failure of their retention dams. Minor releases of fly ash from the storage sites could be early warning signs of their declining retention. When reaching a river, fly ash particles deposit in its sediments. Thereby, fly ash particles may leave a sedimentary record of minor releases over many years, but these particles are difficult to detect due to their small size and low concentration.

We used single particle inductively-coupled plasma time-of-flight mass spectrometry (spICP-TOF-MS) to identify element fractionation patterns in micrometer- and nanometer-sized fly ash particles. Some intermediately-volatile elements such as nickel, cobalt, and vanadium fractionate towards smaller particle sizes during coal combustion. These elements were enriched in fly ash up to three orders of magnitude above the natural sedimentary background levels. We found particles with this characteristic fly ash elemental fingerprint in four depths of a sediment core downstream of a fly ash landfill, indicating fly ash release into the river. Upstream river sediment reference samples, on the contrary, did not contain these particles. The detected releases of fly ash deposited only trace amounts of fly ash in the sediment, which were neither detected applying major and trace element analysis (ICP-OES, ICP-MS, and XRF), nor found through mineralogical (XRD) or morphological (SEM) investigations.

We demonstrated that spICP-TOF-MS can be used to identify fly ash particles in river sediment at previously undetectable concentrations. This technique can thus help assess surface impoundment integrity to prevent catastrophic future spills.
Volcanic Sedimentary Rhythm Characteristics of Early Cretaceous Rhyolite Tuff in Lingshan Island, Eastern Shandong Province and its Indication to Magmatic Dynamic Process
Authors: Liu Ruiyang
Published: March 2022

A set of rhyolitic tuff-mudstone interbedded rock outcrop with good rhythm is developed in the Yangjiaodong area of Lingshan Island, eastern Shandong Province. In order to research the causes of the rhythm formation of the reflected volcanic eruption magmatic dynamics process, the collected sample were analyzed by time-scale series. The analysis model sets the thickness of tuffaceous rhyolite layer of the sample to represent the eruption scale and the thickness of mud layer represents the dormant time of volcanism. Combined with the geological background of the study area, the parameter deposition rate is the deposition rate of volcanic back-arc basin (6.5 m / Ma) with insufficient source supply, and the mudstone compaction factor is 0.3. Based on this, the thickness of different lithology was counted, and the time span of the analyzed sample was calculated to be 2.24Ma. Using Acycle software for quantitative data interpolation, detrending, spectrum analysis, filtering and other processing, got four scale and four kinds of eruption mode. Finally, the scale-time diagram was analyzed, and matched with the melt activation rheological lock-up window to obtain the volcanic activity pulse eruption model, so as to predict the near-surface magma chamber dynamics process.
Evaluating a reservoir parametrisation in a vector-based global routing model for Earth System Model coupling
Authors: Vanderkelen Inne , Gharari Shervan , Mizukami Naoki , Lawrence David M. , Swenson Sean , Clark Martyn , van Griensven Ann , Pokhrel Yadu , Hanasaki Naota , Thiery Wim
Published: March 2022

Humans have fundamentally altered global river flow by constructing reservoirs and building water-diversion schemes for irrigation. Reservoir operation and the regulation of river flow is important for estimating global water fluxes and water availability. Reservoirs and dam management are however generally not represented in Earth System Models. Recently, efforts are made to incorporate human water management in Land Surface Models by improving the irrigation representation and including high-resolution river networks.

Here, we present the integration of a reservoir routine in the vector-based river routing model mizuRoute, to be coupled with the Community Terrestrial Systems Model (CTSM). We use the Hydrologic Derivatives for Modeling and Applications (HDMA) vector-based river network, which is intersected with lake and reservoir polygons from the HydroLAKES and GRanD databases to model both natural lakes and reservoirs. We implement reservoir management based on the parametrization of Hanasaki et al. (2006) and develop an irrigation topology to determine the irrigation water demand for every individual reservoir based on gridded water demands modeled by CTSM.

We then evaluate our reservoir implementation both in a local setup, driven by observed inflow for 26 reservoirs, and in a global-scale setup, driven by gridded runoff from CTSM and using the Hydrologic Derivatives for Modeling and Applications (HDMA) river network. The local simulations show that accounting for reservoirs improves the skill compared to resolving reservoirs with a natural lake parametrization and not accounting for lakes/reservoirs. In the global-scale simulation, the reservoir management and natural lake parametrizations show however similar results, which could be attributed to biases in modeled reservoir inflow. These biases originate from biases in runoff simulated by CTSM and/or unresolved reservoirs on the river network.

This study overall underlines the need to further develop and test water management parametrizations for improving the representation of anthropogenic interference with the terrestrial water cycle in Earth system models.

References:
Hanasaki, N., Kanae, S., & Oki, T. (2006). A reservoir operation scheme for global river routing models. Journal of Hydrology, 327(1–2), 22–41

Mizukami, N., Clark, M. P., Gharari, S., Kluzek, E., Pan, M., Lin, P., Beck, H. E., & Yamazaki, D. (2021). A Vector-Based River Routing Model for Earth System Models: Parallelization and Global Applications. Journal of Advances in Modeling Earth Systems, 13(6).
New insights into the cytotoxicity of mineral fibres: A combined time-lapse video microscopy and in vitro assays study of chrysotile, crocidolite, and erionite fibres
Authors: Di Giuseppe Dario , Scarfì Sonia , Alessandrini Andrea , Bassi Anna Maria , Mirata Serena , Almonti Vanessa , Ragazzini Gregorio , Mescola Andrea , Filaferro Monica , Avallone Rossella , Vitale Giovanni , Scognamiglio Valentina , Gualtieri Alessandro
Published: March 2022

Although in the last 30 years mineral fibres have been the subject of intensive toxicological studies, the actual mechanisms by which mineral fibres exert cytotoxic activity are not fully understood. In this scenario, our work focuses on the monitoring of the very early steps of the interaction between chrysotile, crocidolite and erionite fibres (classified as carcinogenic by the International Agency for Research on Cancer) and macrophages using time-lapse video microscopy coupled with in vitro assays (i.e. LDH cytotoxicity, MTT viability, ROS generation and annexin-FITC/PI apoptosis). All tests were performed on the THP-1 cell line, differentiated into M0 macrophages (M0-THP-1), after acute exposure (8 h) to 25 μg/mL of mineral fibres. Erionite fibres exhibit early toxicity effects while the cytotoxicity induced by chrysotile and crocidolite fibres occurs with a slight delay (ca. 2 h). In concert with literature data, the toxicity of chrysotile and crocidolite is linked to their ability to stimulate Reactive Oxygen Species (ROS) production. ROS are generated by M0-THP-1 cells as a result of frustrated phagocytosis induced by the long asbestos fibres, or produced by asbestos through the redox-active Fe on the fibre surface and metals released into the cell medium as a consequence of the partial dissolution of the fibres. Erionite fibres are able to induce an intracellular ROS increase but this contribution is significantly lower than both crocidolite and chrysotile stimuli. In the short period, crocidolite and chrysotile trigger significant apoptotic phenomena in M0-THP-1 cells while fibrous erionite is associated with early cytotoxicity and probably necrotic-like effect. Because the erionite fibres are short in length, frustrated phagocytosis plays a limited role in the acute toxicity of this fibre. Investigations focused on the intracellular concentrations of Na+ and Ca2+ as a result of cell-fibre interaction suggest an alternative mechanism by which fibrous erionite may induces cell injury and cell death. During phagocytosis erionite fibres quick exchange their extra-framework Na+ with the ions present in the cytosol of M0-THP-1 cells leading to the dysregulation of ionic homeostasis, cell swelling and cell lysis. At the same time, engulfed erionite fibres can reduce the level of cytosolic Ca2+ and interfere with endoplasmic reticulum-mitochondria crosstalk causing a delay in M0-THP-1 induction of apoptosis.
Assessing the coastal impact of medicane Ianos through a wave-current model forced by a multi-model atmospheric ensemble
Authors: Bajo Marco , Ferrarin Christian , Pantillon Florian , Davolio Silvio , Miglietta Mario , Flaounas Emmanouil , Carrió Diego
Published: March 2022

The Mediterranean basin occasionally hosts small intense vortices that evolve in tropical-like cyclones, also called “medicanes”. Although they are more intense over the sea, their landfall may be associated with destructive extreme events, such as heavy precipitation, windstorms, flooding, and marine storminess. On 18 September 2020, medicane Ianos hit the western coast of Greece resulting in flooding and severe damages at specific coastal locations. In this work, we aim at evaluating the impact of medicane Ianos on the sea state and water level through the use of numerical simulations. We applied a coupled wave-current model to an unstructured mesh representing the whole Mediterranean Sea, with a grid resolution varying from 15 km in the open sea to 2 km along the predetermined cyclone path, and up to 500 m along the landfall area (the western Greek coast). In order to investigate the uncertainty of the ocean model derived by the atmospheric modelling of such an intense event, we performed an ensemble of simulations using several coarse (10 km) and high-resolution (2 km) meteorological forcings from different mesoscale models. Also, results obtained using ERA5 reanalysis or IFS analysis are considered as a benchmark. The multi-model approach allows us to assess how the uncertainty propagates from meteorological fields to the ocean quantities and the subsequent coastal impact. The model performance was evaluated against observations retrieved from fixed monitoring stations and satellites. The numerical results show a large spread of the simulated sea conditions. Due to the rugged and complex coastline,  extreme sea levels are localized at specific coastal sites. The ensemble results were combined for proving a set of indicators of the potential impact of such an intense event, in order to assess the effectiveness of this multi-model ensemble approach. This work is part of the COST action CA19109 MEDCYCLONES (European Network for Mediterranean Cyclones in weather and climate) and of the Interreg Italy-Croatia STREAM project (Strategic development of flood management, project ID 10249186).
Mapping groundwater salinity in the arid region of the Horn of Africa
Authors: Araya*1 Dahyann , Podgorski1 Joel , Berg1 Michael
Published: March 2022

Salinization is one of the main threats to groundwater quality around the world, particularly in arid and semi-arid regions (IPCC, 2007). Some of the major causes of high salinity include natural geological conditions, seawater intrusion, climate change affecting patterns of precipitation and evaporation, overexploitation of groundwater and poor irrigation practices (Amer and Vengosh, 2001; Russ et al., 2020). Salinity can reduce the availability of water for humans and wildlife and can negatively impact crop productivity and promote desertification. Desert regions in Somalia, Ethiopia and Kenya have natural characteristics that favour high salinity in groundwater. 80% of the population in the region depends on groundwater (UNICEF, 2020), and 69% of groundwater sources have salinity levels above the WHO health-based drinking water guideline of 1500 µS/cm.

Here, we use machine learning to spatially predict patterns of high salinity with a dataset of 6300 groundwater quality measurements and various environmental predictors. More than 60 predictor variables were tested and 100 iterations of the random forest were performed. Most of the salinity data were clustered, which can lead to sampling issues due to spatial autocorrelation (SAC). As traditional non-spatial validation methods ignore SAC in the data and therefore do not guarantee independence between training and testing data, we instead use spatial cross-validation to address this spatial phenomenon as well as variograms to identify the extent of autocorrelation among variables. Preliminary results indicate that fractured ancient marine deposits, recharge, precipitation, evaporation and proximity to the ocean are the main factors related to high salinity levels. The model performs well with a combined overall accuracy of ~80% and an Area Under the Curve (AUC) of 0.80. Predictive spatial maps of groundwater salinity will be presented along with an analysis of the drivers of salinity.

<img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gepj.f5764ba1e0c165360300461/sdaolpUECMynit/22UGE&app=m&a=0&c=a657542f78ae3ce12aea2c3ee686e9a3&ct=x&pn=gepj.elif&d=1" alt="" width="568" height="587">

Figure 1. Topographic map of the study area and salinity concentration represented by electrical conductivity (EC).
Including Cloud Microphysics Uncertainty in Convective Data Assimilation: Stochastic vs Static Parameter Perturbations
Authors: Posselt Derek J. , Vukicevic Tomislava , Stankovich Aleksa
Published: March 2022

It has long been known that model physics uncertainty can contribute as much or more to errors in forecasting and data assimilation as errors in initial conditions. Many studies have attempted to include the effects of model physics uncertainty in data assimilation by introducing static perturbations to model parameters. In such studies, parameter values are modified at the beginning of a simulation and remain unchanged throughout the duration of the forecast. Uncertainty is spanned by generating an ensemble of forecasts, each member having a different set of parameter values. Other studies have implemented dynamic perturbations to parameters, introducing methods that modify parameter values online in a stochastic fashion.

 

We present here the results of a study that investigates the sensitivity of convective cloud structures to static and stochastic cloud microphysical parameter perturbations. Static parameter values are drawn from a database produced by a Markov chain Monte Carlo algorithm, while stochastic perturbations are applied via a stochastically perturbed parameterization (SPP) scheme. Both static parameter perturbations and SPP are applied to multiple microphysical parameters within a Lagrangian column model, used in several prior published studies. The 1D column microphysics model is forced with prescribed time-varying profiles of temperature, humidity and vertical velocity in such a way as to emulate the environment inside of a convective storm. This modeling framework allows for investigation of the effect of changes in model physics parameters on the model output in isolation from any feedback to the cloud-scale dynamics. 

 

The results are evaluated in terms of changes to the ensemble mean and variance of time evolving profiles of hydrometeor mass quantities, the microphysics processes within the model as well as in terms of the simulated column integral microphysics-sensitive satellite-based  observables. The outcomes of our experiments indicate a high degree of sensitivity of the to the way in which the SPP scheme is implemented. In particular, the distributions from which parameters are drawn, as well as the decorrelation time scale, have a large effect on the simulation outcomes. We discuss the results of SPP, compare with our static perturbation experiments, and note the implications for convective scale data assimilation. 
The inclusion of ice model uncertainty in 3D Glacial Isostatic Adjustment modelling: a case study from the Russian Arctic
Authors: Li Tanghua , Peltier W. Richard , Stuhne Gordan , Khan Nicole , Baranskaya Alisa , Shaw Timothy , Wu Patrick , Horton Benjamin
Published: March 2022

The western Russian Arctic was partially covered by the Eurasian ice sheet complex during the Last Glacial Maximum (~26 ka BP) and is a focus area for Glacial Isostatic Adjustment (GIA) studies. However, there have been few GIA studies conducted in the Russian Arctic due to the lack of high quality deglacial relative sea-level (RSL) data. Recently, Baranskaya et al. (2018) released a quality-controlled deglacial RSL database for the Russian Arctic that consists of ~400 sea-level index points and ~250 marine and terrestrial limiting data that constrain RSL since 20 ka BP. Here, we use the RSL database to constrain the 3D Earth structure beneath the Russian Arctic, with consideration of the uncertainty in ice model ICE-7G_NA, which is assessed via iteratively refining the ice model with fixed 1D Earth model to achieve a best fit with the RSL data. Also, the uncertainties in 3D Earth parameters and RSL predictions are investigated.

 

We find an optimal 3D Earth model (Vis3D) improves the fit with the deglacial RSL data compared with the VM7 1D model when fixed with the ICE-7G_NA ice model. Similarly, we show improved fit in the White Sea area, where 1D model shows notable misfits, with the refined ice model ICE-7G_WSR when fixed with VM7 Earth model. The comparable fits of ICE-7G_NA (Vis3D) and ICE-7G_WSR (VM7) implies that the uncertainty in the ice model might be improperly mapped into 3D viscosity structure when a fixed ice model is employed. Furthermore, fixed with refined ice model ICE-7G_WSR, we find an optimal 3D Earth model (Vis3D_R), which fits better than ICE-7G_WSR (VM7), and the magnitude of lateral heterogeneity decreases significantly from Vis3D to Vis3D_R.  We conclude that uncertainty in the ice model needs to be considered in 3D GIA studies.
Benthic foraminifera as bioindicators of anthropogenic Pollution in the Red Sea Coast, Saudi Arabia
Authors: alKahtanya khaled , Youssef Mohamed , El-Sorogy Abdelbaset
Published: March 2022

Benthic foraminifera as bioindicators of anthropogenic Pollution in the Red Sea Coast, 
Saudi Arabia
Khaled Al-Kahtanya , Mohamed Youssefb,c,*, Abdelbaset El-Sorogyb,da
a Geology and Geophysics Department, College of Science, King Saud University, Riyadh, Saudi Arabia
b Geology and Geophysics Department, College of Science, King Saud University, Saudi Arabia
c Geology Department, Faculty of Science, South Valley University, 83523 Qena, Egypt
d Geology Department, Faculty of Science, Zagazig University, Egypt

Abstract
The concentrations of Fe, Mn, Cu, Ni, Zn, Pb, Cr, Co, and Cd were measured in the two most 
common species of benthic foraminifera S. orbibulus and P. planatus using ICP-MS (Inuctive 
Coupled Plasma-Mass Spectrometer, Thermo Fisher scientific, and Instrument) in order to assess 
the marine contamination. Iron was the most abundant metal (3294), followed by Mn (133), Cu 
(34.7), Zn (28.3), Cr (25), Ni (18.9), Pb (12.2), Co (9.5), and Cd (0.85). The enrichment factor, 
geo-accumulation index, and contamination factor values for certain elements (Cd, Cu, Pb)
indicate that the shells exhibit enrichment and present an ecological risk. The foraminiferal tests 
show highest concentration of Iron amongst the heavy metals recorded in the study area. In 
comparison with surrounding areas of Red Sea coast in Saudi Arabia and Egypt, the heavy 
metals concentrations show higher concentrations than those recorded in those areas, except Iron 
which shows low values than those recorded from Jeddah area and northern Red Sea Coast, of 
Saudi Arabia. The heavy metals contribution to Yanbu coast may be due to natural or 
anthropogenic activities.
Crustal evolution and oceanic core complexes at the Ascension fracture zone – MAR 7° S
Authors: Dannowski Anke
Published: March 2022

The Ascension fracture zone (AFZ) is a double transform fault system and offsets the Mid-Atlantic Ridge axis by 230 km at 7 °S. The transform fault system is consisting of two parallel transform faults, the North and South Ascension Fracture Zone, sandwiching a ~20 km long ridge segment, which we name Ascension Fracture Zone segment. The segment shows strong topographical variations and corrugated surfaces typical for detachment faults that form oceanic core complexes. An elongated massif approximately 50 km east of the ridge axis with transform-parallel striations of over 100 km on top, indicate a detachment fault active for several million years. This would be one of the longest transform-parallel corrugated surface observed anywhere in the oceans. The question arises whether the corrugations belong to one OCC, representing a rather stable crustal accretion, or if several OCCs have been developed, representing a rather variable crustal accretion. Changes in melt supply influence the crustal structure, which in turn can be recognised by seismic methods.

RV Meteor (cruise M62-4) set out to acquire seismic refraction and wide-angle reflection data along a 265 km long spreading parallel transect to image the crustal velocity distribution and the crustal thickness of the intervening short AFZ segment. Densely spaced, every ~9.25 km, ocean bottom seismometers recorded P-wave and converted S-wave energy emitted from a 64 l G-gun cluster at a shot interval of 60 s, equal to ~125 m shot distance.

The results reveal P-wave velocities that vary along the profile from 3.5 km/s to 5 km/s at the seafloor and reach 7.2 km/s in ~6 km depth at the ridge axis and at 3 km to 4 km depth under the ridge shoulders. At larger offsets to the ridge axis. S-wave velocities vary from 2 km/s to 2.5 km/s at the seafloor and increase to 3.5 km/s in ~2 km depth east of the ridge axis, while the S-wave velocities west of the ridge axis show a lower velocity gradient and reach 3.5 km/s in 3 km to 4 km depth. A Vp/Vs ratio >1.9 is observed in areas where seafloor corrugations have been observed. These areas are interpreted as serpentinised mantle material. However, the high Vp/Vs ratio seems to be limited to the upper 1.5 km to 2 km of the subsurface, indicating that the hydration of the seafloor is limited to that depth. The eastern ridge flank is dominated by a high Vp/Vs ratio for offsets larger than 40 km from the ridge axis, however, it is interrupted by small stripes of Vp/Vs <1.9. Thus, in the short AFZ segment, detachment faulting seem to occur continuously over a long period with short interruptions when the magmatic budged exceeds a certain upper limit.