bluuebunny/crossref_metadata_2025 huggingface dataset:
The fate of trace organic compounds and their transformation products along specific hyporheic flow paths
Authors: Reith Christoph J. , Posselt Malte , Spahr Stephanie , Putschew Anke , Amann Finn , Hinkelmann Reinhard , Lewandowski Jörg
Published: March 2022

Trace organic compounds (TrOCs) are frequently detected in surface waters such as rivers. Possible entry pathways into the environment include stormwater runoff, industrial effluents, and wastewater treatment plant (WWTP) effluents. Understanding the behavior of TrOCs and their transformation products (TPs) is important, as they represent a risk to ecosystem and human health. The hyporheic zone of a river shows high turnover rates for nutrients, dissolved organic carbon, metals, pathogens, and TrOCs. Turnover rates are dependent on both, hydrological and biogeochemical conditions. We conducted a high-frequency sampling campaign in the urban lowland River Erpe (Brandenburg, Germany) which receives treated wastewater from the WWTP Muenchehofe. The aim was to study the fate of TrOCs and respective TPs along specific hyporheic flow paths. The basic idea was to enable the sampling of water parcels along specific hyporheic flow paths by forcing the flow path with a pipe (diameter: 8 cm, length: 27 cm, maximum depth: 17 cm) onto a specific path similar to the natural one. Wood on top of the pipe should increase the hyporheic exchange flow through the pipe and mimic the effect of woody debris which is often used in river restorations. Samples from the hyporheic zone and the surface water were taken every 2 hours for 14 hours. The samples were analyzed for oxygen concentrations, redox parameters, nutrients, and TrOCs. We found a clear redox zonation along the flow paths inside the pipes and investigated its impacts on the fate of TrOCs and their TPs. The hyporheic zone proved as an important river compartment for the retention of TrOCs and their TPs.
Deep Learning for Tropical Cyclone Nowcasting: Experiments with Generative Adversarial and Recurrent Neural Networks
Authors: Steptoe Hamish , Xirouchaki Theano
Published: March 2022

Tropical Cyclones (TCs) are deadly but rare events that cause considerable loss of life and property damage every year. Traditional TC forecasting and tracking methods focus on numerical forecasting models, synoptic forecasting and statistical methods. However, in recent years there have been several studies investigating applications of Deep Learning (DL) methods for weather forecasting with encouraging results.

We aim to test the efficacy of several DL methods for TC nowcasting, particularly focusing on Generative Adversarial Neural Networks (GANs) and Recurrent Neural Networks (RNNs). The strengths of these network types align well with the given problem: GANs are particularly apt to learn the form of a dataset, such as the typical shape and intensity of a TC, and RNNs are useful for learning timeseries data, enabling a prediction to be made based on the past several timesteps.

The goal is to produce a DL based pipeline to predict the future state of a developing cyclone with accuracy that measures up to current methods.  We demonstrate our approach based on learning from high-resolution numerical simulations of TCs from the Indian and Pacific oceans and discuss the challenges and advantages of applying these DL approaches to large high-resolution numerical weather data.
Differences in stable carbon isotopic composition in the fine bulk aerosol and gas phases based on seasonally resolved data at a Prague site
Authors: Vodička Petr , Kawamura Kimitaka , Schwarz Jaroslav , Ždímal Vladimír
Published: March 2022

Isotope fractionation between the gas and aerosol phases is an important phenomenon in terms of studying atmospheric processes. Here, we studied seasonal variations in the stable carbon isotope ratio (δ13C) of total carbon (TC; δ13CTC) and water-soluble organic carbon (WSOC; δ13CWSOC) in fine aerosol particles (PM2.5) as well as in the total carbon of the gas phase (TCgas; δ13CTCgas) at a suburban site in Prague, Czech Republic, Central Europe. The most 13C enrichment was found in WSOC, followed by particulate TC, whereas the most 13C depletion was found in gaseous TC. The clear seasonal pattern for all δ13C values (with the highest values in winter and lowest in summer) provides evidence for the presence of different aerosol sources at the site during the year. Despite the different seasonal compositions of carbonaceous aerosols, the isotope differences (Δδ13C) between the analyzed bulk aerosol parts and phases were similar during the seasons. This shows that the fractionation of stable carbon isotopes is a predominantly physical process in which the chemical composition of individual compounds in bulk aerosols does not play a major role.

Acknowledgement: This conference contribution was supported by the Ministry of Education, Youth and Sports of the Czech Republic under the project No. LM2018122, by the ERDF project "ACTRIS-CZ RI" (No. CZ.02.1.01/0.0/0.0/16_013/0001315) and by the Japan Society for the Promotion of Science (JSPS) through Grant-in-Aid No. 24221001. We appreciate the financial support of JSPS fellowship to P. Vodička (P16760) in Japan.

Reference: Vodička, P., Kawamura, K., Schwarz, J., Ždímal, V.: Seasonal changes in stable carbon isotopic composition in the bulk aerosol and gas phases at a suburban site in Prague, Sci. Total Environ., 803, 149767, 2022. https://doi.org/10.1016/j.scitotenv.2021.149767.
Numerical investigation of cell formation in a 2-dimensional differentially heated shell utilizing thermo-electrohydrodynamics
Authors: Gaillard Yann , Haun Peter , Szabo Peter , Sliavin Yaraslau , Egbers Christoph
Published: March 2022

Today models of our atmosphere to study climate change become more and more important not only from a meteorological point of view but also from a global perspective to understand the large-scale motion of planetary waves that transport a large amount of energy. This study investigates numerically such large-scale flows in a simplified 2-dimensional model that is aligned to the AtmoFlow experiment. This experiment is the legacy of the GeoFlow experiment, which investigated planet mantle convection. The AtmoFlow experiment is a spherical shell that mimics a planet at a small scale, where terrestrial gravity is artificially induced by an equivalent electric central force field. This small planet can rotate synchronized or differentially by moving the inner and outer boundaries to simulated planetary rotation. Analogous to a real planet, the poles are cooled and the equator heated. The fluid used in the numerical simulation to mimic a planetary atmosphere is a dielectric fluid with an electric permittivity sensitive to temperature to induce convection similar to a terrestrial buoyancy. While the fluid is also sensitive to the temperate-dependent density, the spherical shell experiments are performed in free space and thus the experiment is planned to be operated on the International Space Station (ISS) after 2024. Flow patterns are retrieved using a Wollaston Shear Interferometry (WSI) and sent back to Earth's ground station.

To be able to investigate the flow structures recorded by the experiment, a numerical model is built. Here we only show 2-dimensional results of the shell in the equatorial plane without rotation. The boundary conditions in these simulations are set to an ideal fixed temperature where the inner shell is heated, and the outer is cooled. To induce thermo-electro-hydrodynamics convection, an electric voltage is applied at the inner shell whereas the outer is grounded. The resulting flow patterns evolve in time and are stationary, quasi-stationary, or chaotic structures. The arising convection cells can be classified using a time-averaged spatial Fast Fourier Transformation (FFT) of the temperature along the mid-gap of the domain to quantify a mode number. The heat transfer is expressed with the Nusselt number and increases with the Rayleigh number. This is reflected by the mode number increasing to a maximum before it decreases when the flow becomes unstable while maintaining a clear structure and mode shape with detaching plumes at the tangent cylinder.
Tools for supporting Sentinel-1 data interpretation: the coast of Granada (Spain)
Authors: Monserrat Oriol , Barra Anna , Reyes-Carmona Cristina , Mateos Rosa Maria , Galve Jorge Pedro , Tomas Roberto , Herrera Gerardo Herrera , Bejar Marta Béjar , Azañón José Miguel , Navarro Jose , Sarro Roberto
Published: March 2022

In the last few years, satellite interferometry (InSAR) has become a consolidated technique for the detection and monitoring of ground movements. InSAR based techniques allows to process large areas providing a high number of displacement measurements with low cost. However, the outputs provided by such techniques are usually not easy, hampering the interpretation and time-consuming. This is critical for users who are not familiar with radar data. European Ground Motion Service (Copernicus) is a new public service that will bring a step forward in this context. However, the capability of exploiting it will still rely on the user experience. In this context, the development of methodologies and tools to automatize the information retrieval and to ease the results interpretation is a need to improve its operational use. Here we propose a set of tools and methodologies to detect and classify Active Deformation Areas, and to map the potential damages to anthropic elements, based on differential displacements. We present the results achieved in the coast of Granada, which is strongly affected by slope instabilities. The methodology is applied at a regional scale and allows to go to a detailed local scale of analysis. The presented results have been achieved within the framework of the Riskcoast Project (financed by the Interreg Sudoe Program through the European Regional Development Fund (ERDF)).

 
Local slope of magnetic field power spectrum in inertial and kinetic ranges of solar wind turbulence
Authors: Pitna Alexander , Safrankova Jana , Nemecek Zdenek , Pi Gilbert , Franci Luca , Park Byeongseon
Published: March 2022

Solar wind, a supersonic flow of plasma embedded in the magnetic field, exhibits turbulent behavior. The character of turbulent fluctuations has been investigated through low cadence measurements of particle distribution function and high cadence magnetic field measurements. One of the most frequently adopted approach in the analysis of the ‘measured’ time series of any particular quantity is the estimation of its power spectral density (PSD). The shape of the PSD then may infer which physical mechanisms govern the evolution of turbulent fluctuations. Generally, every ‘measured’ time series is ‘noisy’ and it differs from the ‘true’ one (measured by an ideal instrument). In turn, the shape of PSD is affected as well. In this paper, we focus on a special case where the signal and noise are independent, i.e., the noise is additive and therefore, the PSD of measured signal can be expressed as a sum of ‘true’ and ‘noise’ PSDs. Moreover, we define a so-called local slope in the framework of continuous wavelet transform as the finite difference derivative between the two consequent values of a global PSD. Employing this technique, we show that the noise of magnetic field measurements of the MFI instrument on board the Wind spacecraft is additive. Finally, we applied the technique to measurements of the Parker Solar Probe close to the Sun. Our preliminary results suggest that our technique may lead to a more accurate estimations of the kinetic range spectral indices.
Impact of metal nanoparticles on tomato growth, physiology and symbiosis with the Fusarium solani FsK strain
Authors: Chrysikopoulos Constantinos V. , Malandrakis Anastasios A. , Kavroulakis Nektarios , Avramidou Marianna , Papadopoulou Kalliope K. , Tsaniklidis Georgios
Published: March 2022

Metal nanoparticles constitute promising, eco-compatible alternatives to be used as nano-fertilizers or nano-fungicides although their potential impact on the agroecosystem is poorly studied. In the present study, the impact of copper (Cu-NPs, CuO-NPs), silver (Ag-NPs) and zinc oxide (ZnO-NPs) nanoparticles (NPs) on tomato plant development, physiological properties and the symbiotic relationship with the endophytic Fusarium solani FsK strain was assessed in comparison with their respective bulk/ionic counterparts. Both NPs and their counterparts did not affect the number of germinated tomato seeds even at higher concentrations except for AgNO3, which significantly decreased seed germination rates. On the contrary, a dose dependent decrease of root length was observed in most NP/bulk treatment cases. This was also the case for dry weight of tomato plants which was also significantly reduced upon treatment with NPs and counterparts especially in the cases of AgNO3, Cu-NPs, ZnO-NPs, and ZnSO4. Although differences between NPs and bulk counterparts varied, root and shoot length of grown tomato plants was also negatively affected by treatments. NPs/bulk counterpart treatments resulted in a marked oxidative stress response as indicated by increased MDA and H2O2 levels of treated plants. Photosynthetic pigments were also significantly affected by NP/bulk treatments, a fact evident from the reduced chlorophyl-a and carotenoid levels recorded. The FsK tomato-symbiotic strain was significantly more sensitive to Cu-NPs and ZnO-NPs than CuO-NPs and Ag-NPs as revealed in both mycelial growth and spore germination fungitoxicity tests. With the exception of AgNO3,which was 8 to 9-fold more toxic than Ag-NPs, all NPs were more fungitoxic to FsK than their bulk/ionic counterparts. FsK colonization of roots was not significantly affected by treatments with NPs and counterparts indicating that, once established inside the roots, the endophyte is shielded against the toxic effect of metals. At the same time, an alleviation of CuO-NPs, ZnO-NPs,and ZnSO4 phytoxicity was observed when FsK was present inside tomato roots in terms of plant dry weight. Concluding, results suggest that phytotoxicity of NPs in tomato treated plants should be considered before nano-fertilizer/fungicide treatments while the benefits of FsK inoculation of tomato plants may extent to resistance towards these toxic agents for both organisms.
Effect of adaptive rootzone development in quantitative land evaluation studies
Authors: Mulder Martin , Heinen Marius , Hack - ten Broeke Mirjam
Published: March 2022

For quantitative land evaluation studies often simulation models are used to express the differences between soil types in terms of water availability or crop productivity. In the Netherlands we developed a land evaluation system specifically for water authorities, provinces and drinking water companies. The system allows answering questions on how water management influences crop development due to too dry or too wet conditions in the unsaturated zone. This system is based on the linked simulation model SWAP (Soil-Water-Atmosphere-Plant) and WOFOST (WOrld FOod STudies). The impact of changes in climate or hydrology can then be studied in terms of effects on crop growth and farm income.

Although SWAP and WOFOST are process based models, the rootzone development is simulated in a straightforward way: the development of the root extension is specified by the user in advance and the root length density distribution is assumed static in time. Because the circumstances within the rootzone is influenced by meteorological, hydrological and soil characteristics it is impossible to design an optimal rootzone development in advance. For a more realistic approach we implemented an adaptive rootzone distribution which will react on the hydrological conditions within the rootzone. This means that newly formed roots will be assigned to regions where there is no or the least stress, and less or no new roots to regions where water stress was experienced. As a result the drought and oxygen stress will be less dependent on the initial root distribution as specified by the user. An example for a regional study will be provided to show the relevance of adaptive rootzone development for assessing land qualities in space and time. 
Optimal trait theory: testing predictions on the Northeast China Transect
Authors: Ding Ruijie , Dong Ning , Ni Jian , Prentice Iain Colin
Published: March 2022

Recently developed ecosystem models based on eco-evolutionary optimality hypotheses can predict many aspects of the carbon, water and nutrient economy of ecosystems. These models have focused on various key plant functional traits and their environmental controls. Gross primary production (GPP) is partly determined by the ratio of intercellular to ambient CO2 concentrations (χ), which can be inferred from leaf stable carbon isotope ratios (δ13C). The effect of nitrogen (N) supply on GPP is mediated by the allocation of carbon (C) to leaves, while leaf-level photosynthetic traits (e.g. χ and photosynthetic capacity) and morphological traits (e.g leaf size and leaf mass per area, LMA) are modified or constrained by climate. The amount of N in the leaf is related in part to the quantity of photosynthetic enzymes, indexed by carboxylation capacity at standard temperature (Vcmax,25), and in part to LMA – as all plant tissues, including cell walls, contain N. Plant N isotope ratios (δ15N) are sensitive to the partitioning of N loss from soil between the gaseous and leaching pathways (a balance that is strongly under climatic control), and also to plants’ N uptake strategy (mycorrhizal type or symbiotic N-fixation).

Plant and ecosystem data collected on the Northeast China Transect (NECT) are used here to test a series of quantitative trait predictions based on optimality principles. The NECT is characterized by a long continuous gradient in precipitation and community structure, ranging from moist forests in the east, via grasslands, to semi-desert in the west. We investigated the relationships among leaf traits, ecosystem properties and N loss pathways, including χ, LMA, leaf N per unit area (Narea), leaf area index (LAI, inferred from satellite data), above-ground biomass, and δ15N. The calculations involve testable predictions of intermediate quantities, including community-mean photosynthetic capacity and GPP. By reproducing observed patterns of trait variation along the NECT, this analysis has provided empirical support for an emerging, optimality-based theory for the coupling of C and N cycles in terrestrial ecosystems.

 
Linking source and sink: geochemistry and zircon U-Pb geochronology provenance record of drainage systems in potential provenance area and Yinggehai-Qiongdongnan Basin, South China Sea
Authors: meng fulin
Published: March 2022

The Yinggehai Basin (YGHB) and Qiongdongnan Basin (QDNB) has received a large amount of terrigenous sediment from different continental blocks since the Paleogene, preserving Cenozoic sedimentary records of the Tibetan Plateau uplift, the tectonic activity of the adjacent plate, and climate change in Southeast Asia. Large scale of oil and gas reservoirs have been discovered in the YGHB and QDNB recently, but the provenance of the marine sediments in this area are poorly understood. In this study, sandstone samples were taken from drilling cores in the joint area of YGHB and QDNB, and cover all Oligocene, Miocene and Pliocene formations. The trace element, rare earth element (REE) and detrital zircon U-Pb geochronology of sedimentary rocks from the Oligocene to Pliocene is examined in this study to investigate the temporal and spatial variations in provenance since the early Oligocene. The Red River has been supplying sediments with positive Eu anomalies from basic-ultrabasic metamorphic and volcanic parent rocks to most parts of two basins, while Hainan Island has delivered sediments with negative Eu anomalies from granitic and sedimentary parent rocks to the eastern slope area of YGHB. The U-Pb ages of detrital zircon range from 3000 to 30 Ma, suggesting that sediment input is derived from multiple sources. Importantly, the Upper Oligocene Formation contained exclusively Cenozoic, Mesozoic, Palaeozoic, and Proterozoic zircon ages, and the age spectrum showed two major peaks at ca. 245 and 423 Ma, indicates that Upper Oligocene sediments in the northwestern area of the QDNB may have originated from the Red River, which had four major peaks at 254, 418, 751, and 1848 Ma, suggesting that sediments from the Red River entered the QDNB as early as the Late Oligocene. Detailed analyses of these components indicate that both the Red River and Hainan are likely the major sources of the sediments in the two basins, with additional minor contributions from Central Vietnam.
Andean geodynamics and the evolution of the Amazonian ecosystem
Authors: Sacek Victor , Mutz Sebastian , Ehlers Todd , Bicudo Tacio , Almeida Renato
Published: March 2022

The evolution of the Amazonian landscape is directly related to the development of the Andean Cordillera and its interaction with climate and other geodynamic processes. The Andean orogeny shaped the climate in South America and changed the precipitation rates across the continent. The continuous increase in erosion rates mainly along the eastern flank of the cordillera amplified the influx of sediments in Amazonia, culminating in the formation of the transcontinental Amazon Drainage Basin nearly 10 million years ago (Ma), connecting the Andean Cordillera and the Equatorial Atlantic Margin. Concomitantly, flexure of the lithosphere due to the load of the Andes and dynamic topography induced by the subduction of the Nazca plate under the western margin of South America modified the landscape in Amazonia.

Due to the complexity of the different processes associated with the geodynamic evolution of northern South America during the last 40 Ma, a natural approach to this study is the use of numerical models that take the interaction of the different geodynamic processes into account. Based on numerical models that combine orogeny, surface processes, flexure of the lithosphere, mantle dynamics, and paleoclimate scenarios, we show how the different habitats in Amazonia probably evolved during the formation of the Andean Cordillera. We observed that the continuous uplift of the Andes created an asymmetric influx of sediments and nutrients in Western Amazonia, inducing the eastward expansion of várzea and terra firme forests during the Miocene. Consequently, the igapó forests retracted and were preserved mainly adjacent to the Guiana and Brazilian shields. Additionally, before the formation of the transcontinental river, large aquatic environments were formed in Western and Central Amazonia, with spatial and temporal extent modulated by climate, sea-level fluctuations, and amplitude of dynamic topography, controlling the transition from the intermittent marine environment to lacustrine conditions, similar to the long-lived lakes of the Pebas System during the Late Miocene. We propose that these landscape evolution scenarios are compatible with the flourishing and extinction of endemic species during the Late Miocene and can explain part of the present pattern of biodiversity observed in the largest rainforest on Earth.
The strong role of external forcing in seasonal forecasts of European summer temperatures
Authors: Patterson Matthew , Weisheimer Antje , Befort Daniel , O'Reilly Christopher
Published: March 2022

Since the 1980s, external forcing from increasing greenhouse gases and declining aerosols has had a large effect on European summer temperatures. The forcing therefore provides an important source of predictive skill, even for timescales as short as seasonal forecasts. However, the relative importance of forcing for seasonal forecasts has thus far not been quantified, particularly for skill on regional scales. In this study, we investigate forcing-induced skill by comparing the skill of the operational multi-model ensemble of seasonal predictions from the Copernicus climate change service (C3S) archive to that of an uninitialized ensemble of CMIP6 projections for European summers for the period 1993-2016.

We show that for some regions, such as northern Europe, the forced trend provides the primary source of 2m temperature skill in current seasonal forecast models at 2-4 month lead-times. Over some parts of northern Europe, summer correlation skill is actually higher in uninitialized predictions and in runs with long lead-times than at short lead-times suggesting that there may be problems with the initialization. Conversely, 2m temperature in the Mediterranean region is generally well predicted by seasonal forecast models out to 4-6 months due to a combination of dynamical skill and a strong forced trend.

We argue that the strong warming trends mean that even uninitialized predictions contain useful information for seasonal forecasts of European summer temperatures. However, the ability of current models to capture summer circulation patterns requires further investigation as it is still unclear whether the models are deficient in this regard or whether the summer is inherently unpredictable.
Global shipping emissions in S5P/TROPOMI data
Authors: Latsch Miriam , Richter Andreas , Lange Kezia , Burrows John P.
Published: March 2022

Ships are important emission sources of nitrogen oxides (NOx), which are relevant pollutants in the atmosphere affecting the environment and human health. For decades, some of the busiest shipping lines have been tracked by satellites from space. With TROPOMI aboard the first European Sentinel satellite for monitoring the composition of the Earth’s atmosphere, the Sentinel 5-Precursor (S5P), the potential for detecting shipping emissions has increased due to its low noise and high spatial resolution of 5.5 x 3.5 km2. Previous studies have shown that even individual ship plumes can be identified from TROPOMI data.

In this study, we evaluate the shipping emissions on a global scale in an attempt to identify as many signals as possible from the TROPOMI data. One important aspect is to focus on finding real shipping signals and avoiding inadvertently interpreting a priori information. The aim of this study is to contribute to the progress of satellite remote sensing of shipping emissions and to better understand air pollution caused by the shipping sector and its effect on the environment.
Punctuated propagation of a corrugated extensional detachment offshore West of Ireland
Authors: Lymer Gaël , Childs Conrad , Walsh John
Published: March 2022

Corrugated detachments are fundamental crustal structures found in many extensional systems and plate tectonic boundaries, including mid-oceanic ridges and rifted margins. Direct observations of the complete geometry of extensional detachments are rare and our understanding of detachment fault structures and the mechanisms of development of high-angle normal faults and their rotation to lower angles mainly relies on proxy observations, for example seismicity trends, and numerical modelling.

We present interpretations of a high-resolution 3D seismic reflection survey from the hyperextended domain of the Porcupine Basin, Offshore West of Ireland. The 3D data image a highly reflective corrugated surface, the P reflector, that we interpret as an extensional detachment preserved in its slip position that likely developed at the top mantle surface during Jurassic hyperextension of the basin. Within the 3D data, the P reflector covers an area 95 km long and 35 km wide and has a domal shape that is elongate in the N-S direction with a crest at ~6.3 s two way travel time. It is the first time to our knowledge that 3D seismic data has imaged a complete detachment in the hyperextended area of a rifted margin, including its domal shape, the breakaway structures, and the linkage between the steep and shallow segments of the detachment. The resolved texture and geometry of the detachment and its relationship with overlying faults provide a basis for refining current models of detachment formation accommodating extreme extension.

Steep west-dipping faults mark the western frontal margin of the detachment. The steep faults pass eastward into shallower, predominantly west-dipping faults that appear to merge downwards with the P reflector. The P reflector has pronounced E-W corrugations, interpreted to indicate the detachment slip vector. The reflector is also characterised by abrupt changes in dip across N-S transverse ridges. These ridges are spaced on average 10 km apart, they coincide with lines of intersection between the P reflector and large overlying faults, and they often mark the termination of detachment corrugations. We interpret these ridges as recording former locations of the western boundary of the detachment so that they indicate a step-wise westward propagation of the P reflector. While it is generally accepted that detachments develop by oceanward propagation, we suggest that the faceted nature of the detachment indicates that this process is a punctuated one and that the clearly imaged transverse ridges record the oceanward stepping of the detachment with the initiation of a new family of steep faults.

We propose a new concept for the growth of detachments that may be applicable to other detachments that accommodate extreme extension, for example at mid-oceanic slow and ultra-slow spreading ridges.
AMPERE and The Electric Current of the Geomagnetic Storm
Authors: Fleetham Amy , Milan Steve , Imber Suzie , Anderson Brian
Published: March 2022

The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) has revolutionized the way in which we can study the electrical current systems present over the poles of Earth. With high cadence measurements taken in both hemispheres, the data has proven invaluable in developing our understanding of the current systems that couple the magnetosphere and ionosphere and how they change in response to space weather. By employing the AMPERE data set, we aim to offer new insights into the complex and dynamic region 1 and region 2 current systems as they respond to the impact of solar wind disturbances on the magnetosphere and the driving of geomagnetic storms.

We investigate the relationship between the hemispherically-integrated current flowing into or out of each pole and upstream solar wind parameters to understand how these currents are driven.  As expected, current magnitude increases with increasing interplanetary magnetic field strength and solar wind speed.  A key aim of the analysis is to determine if current magnitude saturates under strongly driven conditions, in the same way that the cross-polar cap potential is known to saturate.  We present preliminary results, indicating a variety of behaviours at high driving, and discuss these in terms of theories of solar wind-magnetosphere coupling.
New spherical harmonic global geomagnetic field models for the Matuyama-Brunhes reversal
Authors: Mahgoub Ahmed Nasser , Korte Monika , Panovska Sanja
Published: March 2022

The geomagnetic field is created by the motion of molten iron inside the liquid outer core of the Earth. It has undergone a number of drastic changes over geological time, the most notable of which are field reversals, in which the magnetic north and south poles change locations. Because sediments can retain information about past magnetic field directional and intensity changes through depositional or post-depositional remanent magnetization acquisition mechanisms, oceanic sediment cores can be used to track reversals. Lavas also document reversals by spot readings of thermal remanent magnetization. The Matuyama-Brunhes reversal (MBR) was the last time the Earth’s poles reversed, and it is documented by the largest number of sediment records compared to earlier reversals. Investigating the MBR globally therefore can help to understand the physical processes that occur in the Earth’s core. A few global spherical harmonic (SH) models have previously been proposed for the MBR. However, the number, distribution, and timescale reliability of the input data are limitations of these models, the last one of which has been published more than 10 years ago. In this study, we take advantage of new sediments and lava data for the MBR that have been published since these models were developed, and often have better age control and higher temporal resolution than data used in previous SH models. Smoothing splines were used to examine the temporal resolution of all sediment records in our new global compilation, and the results show a median smoothing time of 350 years (±200 years). We present a new global SH geomagnetic field model for the MBR, constructed from 67 sediment cores and 93 lava sites that span the last 900-700 ka and have a reasonable geographical distribution. In addition, we investigate the robustness of model features by deriving models from sub-sets of data, e.g., using only well-dated, high-resolution sediment data that are consistent with surrounding records (if any exist). The model’s featured will be discussed, including (1) field morphology at the CMB and at the Earth’s surface; (2) axial dipole (AD) and non-axial dipole (NAD) power at the CMB; and (3) magnetic energy of AD and NAD fields at the Earth’s surface. Furthermore, we will compare the current models to the previous MBR models.
Tectonic evolution of the northern Verkhoyansk fold-and-thrust belt based on paleostress analysis and U-Pb calcite dating
Authors: Pavlovskaia Elena A. , Khudoley Andrey K. , Ruh Jonas B. , Moskalenko Artem N. , Guillong Marcel , Malyshev Sergey V.
Published: March 2022

The formation of the Verkhoyansk fold-and-thrust belt (FTB) is traditionally interpreted as a result of Late Mesozoic subduction and consequent closure of the Oimyakon Ocean, followed by the collision of the Kolyma-Omolon microcontinent with the Siberian Craton. In particular, the northern Verkhoyansk FTB reflects the complex tectonic history and interaction of the Arctic and Verkhoyansk orogens. Although previous studies documented several Cretaceous deformation events, the details of the northern Verkhoyansk evolution are still poorly understood.

A combined structural and geochronological study was carried out to identify the tectonic evolution of the northern Verkhoyansk FTB. Fault and fold geometries and kinematics were used for paleostress reconstruction in the central and western parts of the northern Verkhoyansk FTB. The multiple inverse method was used to separate individual stress fields from heterogeneous fault-slip data and three different stress fields (thrust, normal and strike-slip faulting) were identified. Thrust and normal faulting stress fields were found throughout the study area, whereas a strike-slip faulting stress field was only found in Neoproterozoic rocks in the westernmost part of the northern Verkhoyansk FTB. Furthermore, U-Pb LA-ICP-MS dating of calcite fibers on slickensides was performed to obtain a first-order time constraint on fault activity.

The study reveals the following succession of major deformation events across the northern Verkhoyansk: i) The oldest tectonic event corresponding to the strike-slip faulting stress field with NE-SW-trending compression axis is Early Permian (284±7 Ma) and likely represents a far-field response to the Late Palaeozoic collision of the Kara terrane with the northern margin of the Siberian Craton. ii) A slickenfibrous calcite age of 125±4 Ma is attributed to the most intense Early Cretaceous compression event, when the modern fold and thrust structure developed. Dykes in the eastern part of the northern Verkhoyansk FTB cutting N-S trending folds with 90-85 Ma U-Pb zircon ages mark the end of this event. iii) U-Pb slickenfiber calcite ages of 76-60 Ma estimate the age of a Late Cretaceous–Palaeocene compression event, when thrusts were reactivated. Slickensides related to both (ii) and (iii) compressional tectonic events formed by similar stress fields with W-E trending compression axes. iv) From Palaeocene onwards, extensional tectonics with approximately W-E extension predominated. Within the northern Verkhoyansk FTB, extension settings are supported by the formation of a set of grabens and a clearly recognizable normal faulting stress field.
Improving the Accuracy of GNSS Orbit Predictions using Machine Learning Approaches
Authors: Gou Junyang , Rösch Christine , Shehaj Endrit , Chen Kangkang , Kiani Shahvandi Mostafa , Soja Benedikt , Rothacher Markus
Published: March 2022

Precise orbit determination is vital for the increasingly vast number of space objects around the Earth. Moreover, accurate orbit prediction of GNSS satellites is essential for many real-time geodetic applications, including real-time navigation. The typical way to obtain accurate orbit predictions is using physics-based orbit propagators. However, the prediction errors accumulate with time because of insufficient modeling of the changing perturbing forces. Motivated by the rapid expansion of computing power and the considerable data volume of satellite orbits available in recent years, we can apply machine learning (ML) and deep learning (DL) algorithms to assess if they can be used to further reduce orbit errors.

In this study, we focus on the orbit prediction of GNSS constellations. We investigate the potential of using different ML and DL algorithms for improving the accuracy of the ultra-rapid products from IGS. As ground truth we consider the IGS final products, and the differences between the ultra-rapid and final products are computed and serve as targets for the ML/DL methods. In this context, we combine the advantages of physics-based and data-driven ML/DL methods. Since the major errors of GNSS orbits are expected to be caused by the deficiency of solar radiation pressure models, we consider different related parameters as additional features to implicitly model the solar impact, such as the C0,0 terms of global ionosphere maps. In order to accurately model the effect of solar radiation pressure on the radial, along-track and cross-track components of the satellite orbit system, the geometric relation between the Sun, the satellite and the Earth are also considered. Furthermore, the performances of different ML/DL algorithms are compared and discussed. Due to the temporal characteristics of the problem, certain sequential modeling algorithms, such as Long Short-Term Memory and Gated Recurrent Unit, show superiority. Our approach shows promising results with average improvements of over 40% in 3D RMS within the 24-hours prediction interval of the ultra-rapid products.
Do upstream factors control fluvial stratigraphic architecture? Insights through quantitative paleohydrology
Authors: Sharma Nikhil , Vérité Jean , Whittaker Alexander C. , Guillocheau François , Puigdefàbregas Cai , Garces Miguel , Valero Luis , Watkins Stephen E. , Adatte Thierry , Castelltort Sebastien
Published: March 2022

Studies have long recognised the role of upstream factors such as sediment flux and water discharge variations in determining the equilibrium river profile. This approach has, however, not been tested in the stratigraphic record of ancient fluvial systems. Here we test the hypothesis that upstream factors control fluvial architecture through changes in water discharge and sediment flux. For this purpose, we utilise the Escanilla sediment routing system, an extensively documented source-to-sink river system in the southern Pyrenees, Spain, and of middle-upper Eocene age (ca. 40 Ma). Our focus is on the locality of Olson, at the distal part of the system, where the gullied landscape allows detailed documentation of fluvial stratigraphic architecture. We describe several fining-upward sequences of 35–40-metre thicknesses with a laterally extensive, amalgamated base overlain by a floodplain-dominated interval containing isolated channel bodies. For each amalgamated and non-amalgamated interval, data pertaining to grain size distributions and flow depths were collected. These data sets were used to perform quantitative palaeohydrological analysis based on paleoslope reconstruction, and from this, we estimated palaeoflow velocity, unit and total discharge, and bedload sediment fluxes. We find that the river slope is lower in the amalgamated intervals as discharge and sediment flux increases, while river slope increases in the non-amalgamated interval as the discharge and flux decreases. Given the available magnetostratigraphic constraints, the studied interval is compared to an astronomical reference curve. The depositional sequences reflecting variations in discharge are likely paced by the major component (413 000 yrs) of the Earth orbital eccentricity variations and thus point to climatic effect on sediment production and transport as the main driver of the fluvial sequences rather than autogenic shifts of the distributive fluvial system, or base-level changes.
Impact on native bees from utility-scale solar development in the Mojave and western Sonoran Deserts
Authors: Saul-Gershenz Leslie , Zavortink Thomas , Van Wyk Jenny , Ascher John S. , Kimsey Lynn
Published: March 2022

We determined the bee species presence, abundance, and diversity at utility-scale ground-mounted solar development (USS) to assess the impact on desert pollinators and the services they provide to the plants in the communities in which they live, specifically, in the Mojave and Colorado Desert regions.  We used a matched transect control design to test whether pollinator populations have changed due to solar utility scale installations. Sixty to 90% of flowering plants require animal pollinators. The Mojave Desert represents a hotspot of bee biodiversity corresponding to its rich botanical diversity of 1512 species. Our study found 113 species in a severe drought year after five drought years (2011-2015). 42% were oligoleges, 10% were polylectic and 29% of the  lacked data on their floral diets. Included were 5 undescribed species in the families Apidae (Tetraloniella, Anthophora -Anthophoroides, Anthophorula,) and Halictidae (Lasioglossum [Dialictus]). In our transect study we found lower abundance, diversity and richness inside the solar installations. However, we did not find a significant effect of distance from solar installation at 2K for our one year study. The BVT traps represented 16% of the collected specimens and 58 species and cup traps represented 83% of traps, and captured 46.7% of the total specimens and 66 species.Of the total bees species captured and identified, 76% are ground-nesting species.
High resolution (1 km) soil moisture and precipitation for developing a Digital Twin Earth for hydrology
Authors: Brocca Luca , Ciabatta Luca , Massari Christian , Camici Stefania , Barbetta Silvia , Tarpanelli Angelica , Filippucci Paolo , Dari Jacopo , Mosaffa Hamidreza
Published: March 2022

In recent years, the availability of high-resolution observations (<1km, sub-daily) from remote sensing, in situ monitoring networks and new sensors/techniques (drones, citizen science), in addition to the increased computational and storage capacity, have fostered the development of modelling systems at high resolution for hydrological applications. The European Commission (EC) is promoting these developments through the EU’s digital strategy, the Green Deal, and specifically the Destination Earth initiative. The development of digital twins of the Earth System is currently in the EC agenda as one of the most pressing activities to be accomplished to build a resilient society able to cope with adverse extreme events (flood, drought, heatwaves, landslides), exacerbated by global and climate changing.

Despite the high-resolution hydrology is an important opportunity for future research and operation applications, the challenges to be addresses are quite a lot and non-trivial. First, the increased computational capabilities are far from being sufficient to develop high resolution hydrological systems because observations (e.g., precipitation, evapotranspiration, soil moisture, river discharge) have to be available not only at high resolution, but also with sufficient accuracy. A second problem is related to the representation of physical processes that, at high resolution, are significantly different from processes at coarse resolution (20km), currently modelled at large scale. Last but not least, the human impact on the water cycle (e.g., irrigation, reservoir management, river water diversion) acting at very high resolution, challenges the current attempts of reproducing a digital replica of the Earth.

The launch of Sentinel-1 satellites has opened a number of opportunities for developing high resolution satellite soil moisture and precipitation products. These products are an important element for building a Digital Twin Earth (DTE) for Hydrology, i.e., for the reconstruction of the water cycle at high resolution. In this contribution we will present the recent advances over this topic carried out under European Space Agency projects DTE Hydrology and Irrigation+. Specifically, we will present the application of high-resolution products for hydrological applications: flood simulation, landslide risk prediction and irrigation water management. Finally, the main challenges to be addressed will be discussed.
Imaging oceanic basins with wave equation and radiative transfer models
Authors: Nardoni Chiara , De Siena Luca , Cammarano Fabio , Magrini Fabrizio , Mattei Elisabetta
Published: March 2022

When seismic information is used to map Earth structures, a primary challenge is modelling the response of seismic wavefields to strong lateral variations in medium properties. These variations are especially relevant across oceanic basins with mixed continental-oceanic crust and including magmatic systems. These highly-scattering and absorption media produce stochastic signatures that are hard to separate from complex coherent reverberations due to shallow Moho. The discrimination between these two effects is fundamental for improving full-waveform techniques when imaging oceanic basins at regional and global scales. Here, we present a joint tomographic and modelling approach focusing on the ~1 Hz frequency band, where seismic scattering and attenuation mechanisms are predominantly resonant. Firstly, we image late-time coda attenuation as a marker of seismic absorption across the Italian peninsula and the Tyrrhenian Sea. Regional-scale data provide the ideal benchmark to explore the potential of attenuation imaging using radiative-transfer-derived sensitivity kernels in a mixed continental-oceanic crust. Then, we explore the response of seismic wavefield to structural variations combining coda-attenuation imaging with simulations based on radiative transfer and wave-equation modelling. The results provide evidence of intra-crustal reverberations and energy leakage in the mantle, finally being able to map Moho depths with regional earthquakes. This work is an ideal forward model of seismic wavefields recorded across the oceanic crust for future full-waveform inversions and imaging of crustal discontinuities.
Comparison of the Tidal Signatures in Sporadic E and Vertical Ion Convergence Rate, Using FORMASAT-3/COSMIC Radio Occultation Observations and GAIA Model
Authors: Sobhkhiz-Miandehi Sahar , Yamazaki Yosuke , Arras Christina , Miyoshi Yasunobu , Shinagawa Hiroyuki
Published: March 2022

Sporadic E or Es is a transient phenomenon where thin layers of enhanced electron density appear in the ionospheric E region (90-120 km altitude). Es can influence radio propagation, and its global characteristics have been of great interest to radio communications and navigations. The presence of neutral wind shear caused by atmospheric tides will lead ions to converge at E-region heights and form Es layers.The neutral wind shear caused by atmospheric tides can lead ions to converge vertically at E-region heights and form the Es layers. This research aims to determine the role of atmospheric solar and lunar tides in Es occurrence. For this purpose, radio occultation data of FORMASAT-3/COSMIC have been used, which provides complete global coverage of Es events. Moreover, GAIA model simulations have been employed to evaluate the vertical ion convergence induced by solar tides. The results show both migrating and non-migrating solar tidal signatures and the semidiurnal migrating lunar tidal signature in Es occurrence. The seasonal variations of the diurnal and semidiurnal solar migrating components of Es are in good agreement with those in the zonal wind shear. Furthermore, some non-migrating components of solar tides also have a significant effect on the Es occurrence rate.