bluuebunny/crossref_metadata_2025 huggingface dataset:
FAMÍLIA E SUAS CONTRIBUIÇÕES PARA APRENDIZAGEM ESCOLAR NA EDUCAÇÃO INFANTIL: UM ESTUDO DE CASO NA REDE PÚBLICA MUNICIPAL DE FORTALEZA – CEARÁ
Authors: Meneses Mirandy Vieira Coelho de , Pordeus Marcel Pereira , Talmag Juliana Márcia Alencar
Published: March 2021

Esta pesquisa é um recorte de minha dissertação de mestrado na Universidad Interamericana, para tanto, contamos com o apoio de dois pesquisadores na área da educação, para a produção e fragmentação dos assuntos mais relevantes para construção deste artigo. A família é o primeiro espaço de socialização que acontece na infância, a partir das interações, padrões de comportamento, valores e costumes que serão transmitidos para o desenvolvimento da personalidade do indivíduo. Portanto, a relevância deste trabalho encontra-se no esclarecimento de questões educacionais a partir do tema “A família e suas contribuições para aprendizagem escolar na Educação Infantil: um estudo de caso na rede pública municipal de Fortaleza – Ceará”. Objetivou-se averiguar as contribuições da família no processo de aprendizagem escolar na Educação Infantil (doravante EI). A pesquisa foi realizada numa creche pública do município de Fortaleza, Ceará no período de janeiro a dezembro de 2017. Nos embasamos em revisão da literatura que trata da temática, a partir da metodologia utilizada por meio da Pesquisa Bibliográfica e do referencial teórico e metodológico embasado em autores, tais como: Ariès (1973), Bock (2001), Kaloustian (2000), e com os estudos dos teóricos como Jean Piaget. Posteriormente, a segunda etapa do estudo ocorreu através de observação de um grupo de crianças em seu cotidiano escolar com o intuito de relacionar seu desempenho com as assertivas dos autores e pesquisadores deste trabalho. Ao averiguar as informações adquiridas na pesquisa foi possível constatar que as crianças bem assistidas pelas famílias, e que estas demonstravam preocupação com seu desenvolvimento, valorizando e reconhecendo a importância da EI, foram as que tiveram melhores resultados no seu processo de aprendizagem escolar. Já as crianças com menor incentivo dos familiares apresentaram progressos discretos e graduais, percebidos nas avaliações das professoras. Conclui-se que a família pode influenciar, positivamente ou negativa no processo de aprendizagem escolar das crianças dependendo da sua postura para com elas e com a instituição escolar.
Extreme value statistics of interval maximum amplitudes due to aftershocks and its application for early forecast
Authors: Sawazaki Kaoru
Published: March 2021

Waveforms from many aftershocks occurring immediately after a large earthquake tend to overlap in a seismogram, which makes it difficult to pick their P- and S-wave phases. Accordingly, to determine hypocenter and magnitude of the aftershocks becomes difficult and thereby causes deterioration of earthquake catalog. Using such deteriorated catalog may cause misevaluation of ongoing aftershock activity. Since aftershock activity is usually most intense in the early period after a large earthquake, requirement of early aftershock forecast and deterioration of the aftershock catalog are impatient.

Several methods for aftershock forecast, using deteriorated automatic earthquake catalog (Omi et al., 2016, 2019) or continuous seismic envelopes (Lippiello et al., 2016), have been proposed to overcome such a situation. In this study, I propose another method that evaluates excess probability of maximum amplitude (EPMA) due to aftershocks using a continuous seismogram. The proposed method is based on the extreme value statistics, which provides probability distribution of maximum amplitudes within constant time intervals. From the Gutenberg-Richter and the Omori-Utsu laws and a conventional ground motion prediction equation (GMPE), I derived this interval maximum amplitude (IMA) follows the Frechet distribution (or type Ⅱ extreme-value distribution). Using the Monte-Carlo based approach, I certified that this distribution is well applicable to IMAs and available for forecasting maximum amplitudes even if many seismograms are overlapped.

Applying the Frechet distribution to the first 3 hour-long seismograms of the 2008 Iwate-Miyagi Nairiku earthquake (MW 6.9), Japan, I computed the EPMAs for 4 days at 4 stations. The maximum amplitudes due to experienced aftershocks proceeded following mostly within the 10 % to 90 % EPMA curves. This performance may be acceptable for a practical use.

Differently from the catalog-based method, the proposed method is almost unaffected by overlap of seismograms even in early lapse times. Since it is based on a single station processing, even seismic “network” is not required, and can be easily deployed at locations of poor seismic network coverage. So far, this method is correctly applicable for typical mainshock-aftershock (Omori-Utsu-like) sequence only. However, potentially, it could be extended to multiple sequences including secondary aftershocks and remotely triggered earthquakes.
Linking Lithospheric Structure, Mantle Flow and Intra-Plate Volcanism
Authors: Duvernay Thomas , Davies Rhodri , Mathews Christopher , Gibson Angus , Kramer Stephan
Published: March 2021

Several of Earth's intra-plate volcanic provinces cannot be explained solely through the classical mantle plume hypothesis. Instead, they are believed to be generated by shallower processes that involve the interplay between uppermost mantle flow and the base of Earth's heterogeneous lithosphere. The mechanisms most commonly invoked are edge-driven convection (EDC) and shear-driven upwelling (SDU), both of which act to focus upwelling flow, and the associated decompression melting, adjacent to steps in lithospheric thickness.

In this study, we first undertake a systematic numerical investigation, in both 2-D and 3-D, to quantify the sensitivity of EDC, SDU and their associated melting to several key controlling parameters, in the absence of mantle plumes. Our simulations demonstrate that the spatial and temporal characteristics of EDC are sensitive to the geometry and material properties of the lithospheric step, in addition to the depth-dependence of upper mantle viscosity. These simulations also indicate that asthenospheric shear can either enhance or reduce upwelling velocities and predicted melt volumes, depending upon the magnitude and orientation of flow relative to the lithospheric step. When combined, such sensitivities explain why step changes in lithospheric thickness, which are common along cratonic edges and passive margins, only produce volcanism at isolated points in space and time. Our predicted trends of melt production suggest that, in the absence of potential interactions with mantle plumes, EDC and SDU are viable mechanisms only for Earth's shorter-lived, low-volume intra-plate volcanic provinces.

To complement the results from our first numerical investigation, we subsequently explore how the upwelling of a mantle plume within our 3-D domain modifies the occurrence of melting, both in terms of spatio-temporal distribution and intensity. Preliminary results indicate that edges close to the location of plume impingement have their melting shut off as a result of the intense flow generated through sub-lithospheric spreading. Additionally, the heterogeneous distribution of continental lithosphere thickness constrains plume material spreading and results in melting patterns that do not directly reflect the path of the plume relative to the lithosphere, as described by classical mantle plume theory.
Interplay of near surface rift evolution and deep-seated lower crustal flow: New findings from fully quantified crustal-scale analogue models
Authors: Schmid Timothy , Schreurs Guido , Adam Jürgen , Hollis Dave
Published: March 2021

Here we present new results and findings from an analogue modelling series using an extension gradient to simulate continental rifting in rotational settings. We study the effect of a pressure-gradient driven, rift-axis parallel lower crustal flow on rift propagation. The dynamically scaled two-layer models represent a brittle upper and a ductile lower crust. To simulate different crustal set-ups, we use variable ductile/brittle ratios RDB, where increasing values indicate a hotter crust with the brittle-ductile transition at relatively shallower depth. An additional package of sand on one part of the model simulates tectonic loading to provoke a pressure-gradient driven lower crustal flow.

Several factors play a role in dynamic rift propagation such as extension rates, fault evolution and the interplay of vertical motions at the surface as well as model-internal rift-axis parallel horizontal flow. We combine surface and internal deformation analysis using stereoscopic Digital Image Correlation and Digital Volume Correlation applied on surface stereo images and XRCT images, respectively to obtain the fully quantified model deformation.

Our results show that rift propagation occurs in two consecutive stages: (i) bidirectional step-wise growth in fault length by linkage and (ii) unidirectional linear fault growth. Strain partitioning of bulk extension causes episodic alternative fault growth on conjugate rift margin faults. Over time, fault activity abandons rift boundary faults and migrates inward creating intra-rift faults. This process occurs segment-wise along the rift axis, where different fault generations are simultaneously active. We quantify increasing lower crustal flow parallel to the rift axis with increasing RDB as the result of tectonic loading. In return, such lower crustal flow causes vertical and horizontal motions at the surface expressed by dynamic topography and deformation features.

These results give insights into deformation processes of rifting and highlight the important role of extension gradients on fault growth and strain partitioning in segmented rotational rift systems. Rift-axis parallel lower crustal flow in rotational rift settings may be of relevance when dealing with restorations of 2D crustal seismic sections across rifts.
Inter-comparison of remotely-sensed actual evapotranspiration products in the Zayandehrud river basin, Iran
Authors: Abbasi Neda , Nouri Hamideh , Chavoshi Borujeni Sattar , Nagler Pamela , Opp Christian , Barreto Munez Armando , Didan Kamel , Siebert Stefan
Published: March 2021

Accurate estimation of evapotranspiration (ET) helps to create a better understanding of water allocation, irrigation scheduling, and crop management especially in arid and semiarid regions where agricultural areas are far more affected by water shortage and drought events. Remote sensing (RS) facilitates estimating the ET in regions where long-term field measurements are missed.  In this study, we compare the performance of free open-access remotely sensed actual ET products at eleven counties of the Zayandehrud basin. The Zayandehrud basin, one of the major watersheds of Iran, suffers from recurrent droughts and long-term impacts of aridity. The RS products used in this study are namely WaPOR (2009-2019), MOD16A2 (2003-2019), SSEBOp (2003-2019). We also merged the two products of SSEBOp and WaPOR and assessed its performance. To prepare the Merged ETa Product (MEP), WaPOR was resampled to the spatial resolution of SSEBOp. Then, the average pixel values of the resampled ETa product and SSEBOp were calculated. To compare ETa estimations over croplands in each county, maximum Normalized Difference Vegetation Index (NDVI) maps at annual scale (2003-2019) were prepared using LANDSAT 5, 7, and 8 images. Annual mean ETa estimations were then extracted over croplands by using annual maximum NDVI layers. We compared the RS-based ETa with reported long-term ETa values extracted from the local available literature. Our results showed a consistent underestimation of MOD16A2 in all counties. The MEP and WaPOR outperformed other products in the estimation of ETa in seven. Estimations of WaPOR and SSEBOp agreed in most of the counties. Our analysis displayed that, although MOD16A2 underestimated ETa values, it could together with SSEBOp capture the drought better than that of WaPOR and MEP in the lower reaches of the basin. Further study is needed to evaluate the monthly and seasonal performance of RS-based ETa products.
Extratropical low-frequency variability with ENSO forcing: a reduced-order coupled model study  
Authors: Vannitsem Stéphane , Demaeyer Jonathan , Ghil Michael
Published: March 2021

The impact of the El Niño-Southern Oscillation (ENSO) on the extratropics is investigated in an idealized, reduced-order model that has a tropical and an extratropical module. Unidirectional forcing is used to mimic the atmospheric bridge between the tropics and the extratropics. The variability of the coupled ocean--atmosphere extratropical module is then investigated through the analysis of its pullback attractors (PBA). This analysis focuses on two ENSO-type forcings generated by the tropical module, one periodic and one aperiodic.

 

For a substantial range of coupling parameters, multiple chaotic PBAs are found to coexist for the same set of parameter values. Different types of extratropical low-frequency variability are associated with each PBA over the parameter ranges explored. For periodic ENSO forcing, the coexisting PBAs are nonlinearly stable, while for the chaotic forcing, they are unstable and certain extratropical perturbations induce transitions between the PBAs. These distinct stability properties may have profound consequences for extratropical climate predictions, provided they are confirmed by studies using comprehensive climate models. Thus, for instance, ensemble averaging may no longer be a valid approach to isolate the low-frequency variability signal.
Thrust-fault dynamics and frictional resistance response inferred though laboratory earthquakes
Authors: Tal Yuval , Runino Vito , Rosakis Ares , Lapusta Nadia
Published: March 2021

Observational and numerical studies have shown that the asymmetric geometry of thrust faults with respect to the Earth’s surface leads to a complex dynamic behavior of updip ruptures. Here, we use an experimental technique that combines ultrahigh-speed photography and digital image correlation to characterize the dynamics of transitioned supershear laboratory thrust earthquakes near the free surface with coherent full-field maps of dynamic displacements, velocities, and stresses associated with the ruptures at intervals of one microsecond. The experimental measurements visualize how the free surface breaks the symmetry in the velocity field with a larger velocity magnitude at the hanging-wall and significant rotations into a nearly vertical motion of the hanging wall and footwall motion at a dip angle much shallower than that of the fault. As indicated by the evolving stress maps, these rotations lead to significant normal stress reductions, with a temporal complete release in experiments that were conducted under small initial compressive load. The method enables us to measure the evolving on-fault friction in real time and to unravel the history dependent nature of friction on slip, slip rate as well as fast variations in normal stress. We show that the shear frictional resistance exhibits a significant lag in response to normal stress variations and identify a predictive frictional formulation that captures this effect. Our findings provide guidance to theoretical earthquake source mechanics models by furnishing the necessary on-fault physics needed for the numerical simulation of the rupture process.
Early Jurassic phytotoxicity due to Hg-remobilization
Authors: Bos Remco , Lindström Sofie , Sanei Hamed , Waajen Irene , Sluijs Appy , van de Schootbrugge Bas
Published: March 2021

The Central Atlantic Magmatic Province (CAMP) eruptions are generally regarded as the main driver of major environmental change and mass-extinction across the Triassic-Jurassic (TJ) boundary (~201.3 Ma), but the exact mechanisms linking volcanism and extinction, resilience, and recovery remain poorly constrained. Volcanogenic mercury (Hg) has been implicated as the cause for mutations in spores/pollen indicating severe ecological stress in terrestrial vegetation. Indeed, elevated sedimentary Hg concentrations coincide with the extinction interval at multiple sites across Europe. Here we show, palynological and geochemical records that gives insight in the dynamics between the Hg cycle and terrestrial vegetation, indicating repeated phytotoxicity in Early Jurassic deposits.

The abundance of mutagenic spores and the concentration of Hg are quantified in shallow marine sediments in the Schandelah-1 core (northern Germany) across the T/J boundary and the Early Jurassic (Hettangian). The results show increased mutagenic spore abundances with accompanying Hg/TOC anomalies across the end-Triassic extinction and within the lowermost Hettangian. This is consistent with studies from Sweden and Denmark and therefore confirming synchronous mutagenesis in and around coastal European margins. In addition, the Hettangian of Schandelah contains a record of long-term vegetational disturbance in the form of recurrent fern spikes and elevated mutagenic spore intervals, accompanied by Hg/TOC anomalies of similar magnitude. This suggests an overall link between volcanogenic pollution and vegetational disturbance. Based on qualitative analyses of organic matter (OM), which show an overall positive correlation between Hg concentration and terrestrial indicators, alternative sources for sedimentary Hg-enrichment such as vegetation reservoirs should be considered. This characterization of OM indicates an intermediate step in the Hg cycle, likely mediated by vegetation and/or climate feedbacks.

Atmospheric Hg-loading via volcanism can explain the synchronous enrichments of Hg concentrations at the TJ boundary interval in multiple sites across the globe. In contrast, the Hettangian anomalies of Schandelah-1, appear to be mainly driven by environmental/ecological perturbations corresponding to intensifying warm/humid conditions. Extreme seasonality alternating between high rainfall and droughts, perhaps due to eccentricity maxima, leading to increased soil erosion, wildfires and transport/degradation of terrestrial OM could potentially recycle and redistribute Hg long after initial deposition. These implications suggest a more dominant role of climate-induced Hg-remobilization, rather than direct volcanic emissions, to the mutagenesis in terrestrial vegetation. This could, in addition, lead to asynchronous and local impacts mainly in the proximity of landmasses.
Testing of the usability of the C-band Electronic Corner Reflector (ECR-C) in Hungary based on Sentinel-1 SAR data
Authors: Horvath Roland , Toth Sandor , Magyar Balint
Published: March 2021

The key infrastructural elements of the geodetic application of the Interferometric Synthetic Aperture Radar (InSAR) are the integrated benchmarks which are satellite technologies, besides the traditional geodetic technologies, therefore they serve as benchmarks of the Global National Satellite System (GNSS) and InSAR.

Previously, the Satellite Geodetic Observatory (SGO) has already built a network of the passive corner reflectors (SENGA) near the Hungarian GPS Geokinematic Reference Network. This infrastructure is added by an active corner reflector (called transponder) which is the first device according to our knowledge in Hungary. We have been testing the transponder in recent months. The scope of our work is the detection of the intensity of the emitted radar signal by the Sentinel-1 C-band satellite VV polarisation sensor using GAMMA Remote Sensing Software with 6 day repeat cycle availability of satellite images in ascending and descending passes. Hence, we could monitor and compare of the pixel-intensity (expressed in decibel) before and after the installation. The value of the pixel is increased around 15-20 dB and we had chance to set the Radar Cross Section (RCS=31 dBm2) against the results of existing researches. During the testing period the ECR was placed on the rooftop of the SGO, but in the short-term the design of the relocation of the device as InSAR Persistent Scatterer has also been developed.

One of the goals of our research is the incorporation of the transponders into the SENGA network which is needed to be expanded, examination and determination of the conditions of this integration.

 
The impact of freeze-thaw-cycles on soil structure and soil hydraulic properties
Authors: Leuther Frederic , Schlüter Steffen
Published: March 2021

The ploughing of soils drastically alters soil structure and at the same time reduces its stability against external stresses. A fragmentation of these artificially produced soil clods during winter time is often observed in areas with air temperatures fluctuating around the freezing point. In this study, the cumulative effects of multiple freeze-thaw cycles (FTCs) on soil structure and soil hydraulic properties were analyzed for two different soil textures, a silty clay loam with a substantial amount of swelling clay minerals and a silty loam with less swell/shrink dynamics. The soil material was brought into two different initial states: (i) undisturbed soil cores taken from the topsoil from a grassland, and (ii) cylinders repacked with soil clods taken from a ploughed field nearby. FTCs were simulated under controlled conditions in the lab, changes in soil structure ≥48 µm were regularly recorded using X-ray µCT. After 19 FTCs, the impact on hydraulic properties were measured and the resolution of structural characteristics were increased to 10 µm by subsampling.

The effect of FTC on soil structure was found to be dependent on the initial structure, soil texture and number of FTCs. Freezing and thawing induced a consolidation of the repacked soil clods taken from both field sites, resulting in a systematic reduction in pore sizes and macro-pore connectivity. The macro-pore system of the undisturbed samples was only slightly affected. Fragmentation of soil elements larger than 0.8 to 1.2 mm increased the connectivity of pores smaller than 0.5 to 0.8 mm. Frost action increased the unsaturated hydraulic conductivity of all treatments, while the water retention was only slightly affected. This leads to the conclusion that multiple FTCs enforces a well-connected meso-pore system at the expense of a fragile macro-pore system. A change in soil structure that benefits farmers but could be reduced in the face of milder winters due to global warming.
qgs: A flexible Python framework of reduced-order multiscale climate models
Authors: De Cruz Lesley , Demaeyer Jonathan , Vannitsem Stéphane
Published: March 2021

In atmospheric and climate sciences, research and development is often first conducted with a simple idealized system like the Lorenz-N models (N ∈ {63, 84, 96}) which are toy models of atmospheric variability. On the other hand, reduced-order spectral quasi-geostrophic models of the atmosphere with a sufficient number of modes offer a good representation of the dry atmospheric dynamics. They allow one to identify typical features of the atmospheric circulation, such as blocked and zonal circulation regimes, and low-frequency variability. However, these models are less often considered in literature, despite their demonstration of more realistic behavior.

qgs (Demaeyer et al., 2020) aims to popularize these systems by providing a fast and easy-to-use Python framework for researchers and teachers to integrate this kind of model. The documentation makes it clear and efficient to handle the model, by explaining the equations and parameters and linking these to the code. 

The choice to use Python was specifically made to facilitate its use in Jupyter Notebooks and with the multiple recent machine learning libraries that are available in this language.

In this talk, we will present the modeling capabilities of qgs and show its usage in a varieties of didactical and research use cases.

Reference

Demaeyer, J., De Cruz, L., & Vannitsem, S. (2020). qgs: A flexible Python framework of reduced-order multiscale climate models. Journal of Open Source Software, 5(56), 2597, https://doi.org/10.21105/joss.02597 .
Theoretical core spectroscopy of molecules interacting with ice surfaces 
Authors: Opoku Richard Asamoah
Published: March 2021

Céline TOUBIN2 and André Severo Pereira GOMES 3

2,3 Laboratoire de Physique des Lasers, des atomes et des Molécules, Université de Lille, Cité Scientifique, 59655 Villeneuve d’Ascq Cedex, France

E-mail : celine.toubin@univ-lille.fr2 ; andre.gomes@univ-lille.fr3

Ice plays an essential role as a catalyst for reactions between atmospheric trace gases. The uptake of trace gases to ice has been proposed to have a major impact on geochemical cycles, human health, and ozone depletion in the stratosphere [1]. X-ray photoelectron spectroscopy (XPS) [2], serves as a powerful technique to characterize the elemental composition of such interacting species due to its surface sensitivity. Given the existence of complex physico-chemical processes such as adsorption, desorption, and migration within ice matrix, it is important to establish a theoretical framework to determine the electronic properties of these species under different conditions such as temperature and concentration. The focus of this work is to construct an embedding methodology employing Density Functional (DFT) and Wave Function Theory (WFT) to model and interpret photoelectron spectra of adsorbed halogenated species on ice surfaces at the core level with the highest accuracy possible. 

We make use of an embedding approach utilizing full quantum mechanics to divide the system into subunits that will be treated at different levels of theory [3].

The goal is to determine core electron binding energies and the associated chemical shifts for the adsorbed halogenated species such as molecular HCl and the dissociated form Cl- at the surface and within the uppermost bulk layer of the ice respectively [4]. The core energy shifts are compared to the data derived from the XPS spectra [4].

We show that the use of a fully quantum mechanical embedding method, to treat solute-solvent systems is computationally efficient, yet accurate enough to determine the electronic properties of the solute system (halide ion) as well as the long-range effects of the solvent environment (ice).

We acknowledge support by the French government through the Program “Investissement d'avenir” through the Labex CaPPA (contract ANR-11-LABX-0005-01) and I-SITE ULNE project OVERSEE (contract ANR-16-IDEX-0004), CPER CLIMIBIO (European Regional Development Fund, Hauts de France council, French Ministry of Higher Education and Research) and French national supercomputing facilities (grants DARI x2016081859 and A0050801859).

 
The contribution of the former Aral Sea and other desiccating lakes to the prevalence of dust storms in Central Asia and the Middle East
Authors: Banks Jamie , Heinold Bernd , Schepanski Kerstin
Published: March 2021

The 'Aralkum' desert (the former Aral Sea) in Central Asia is a comparatively new desert that has formed over the past several decades due to water mismanagement associated with the inflowing Amu Darya and Syr Darya rivers, and is now a known source of dust aerosol in the region. It is known that recently dry lakebeds can be efficient dust sources, due to the availability of readily erodible alluvial sediments. As a dry lakebed with a new area of over 60,000 km2 exposed to aeolian wind erosion the Aralkum has become a significant driver of dust storms in the region. Other such lakebed dust sources in the Central Asian region include the Sistan Basin on the border between Afghanistan and Iran, and Lake Urmia in Iran. However due to a paucity of measurement sites it is difficult to quantify the behaviour and consequences of dust activity in the region.

Using the dust transport model COSMO-MUSCAT we simulate dust emissions over the course of one year from these relatively new dust sources, exploring the resultant dust emission and transport patterns, quantifying the radiative effects of this dust, and assessing the viability of measuring such dust using remote sensing techniques. Making use of the Global Surface Water dataset (produced by the Copernicus Programme) in order to define the surface water coverage in various epochs, we make estimates of dust emissions for the Central Asian and Middle Eastern region under three scenarios: 1) the 'Past', representative of water coverage in the 1980s; 2) the 'Present', representative of water coverage in the 2010s; and 3) the 'Aralkum' scenario, representing only dust emissions from the present-era Aralkum. In the Present scenario we estimate that the Aralkum area (here considered as 43-47°N, 58-62°E) emitted 28 Tg of dust over the course of a year from March 2015 to March 2016, out of 272 Tg produced by the wider Middle Eastern and Central Asian region. However ~66% of these Aralkum emissions occurred when the cloud cover was > 95%, raising questions as to the extent to which dust storm activity from the Aralkum is measurable. Modelling is therefore a particularly useful tool, complementary to remote sensing measurements, to understand dust activity in a region characterised by dramatic human-induced changes to the natural environment.
Enhanced root growth but reduced belowground carbon allocation are the initial responses to water limitation in model Scots pine-soil systems
Authors: Solly Emily , Jäger Astrid , Barthel Matti , Six Johan , Hartmann Martin
Published: March 2021

Worldwide tree species have been observed to be suffering from extended periods of water limitation, for example due to warmer climate that increases soil evaporation and plant transpiration. These conditions likely do not only affect the growth and vitality of trees but may also feed back on the cycling of carbon and nitrogen at the interface between roots and soils.

In September 2019, we established a mesocosm experiment to mechanistically study on a seasonal basis how the interactions between plants and soil biotic and abiotic resources are altered during events of drought. The mesocosms feature young Scots pine (Pinus sylvestris L.) trees and soil collected from a drought-affected natural forest in the Rhone valley, Switzerland; and are treated with three different levels of water availability (control, sufficient water; intermediate drought, 40% reduction; severe drought, 75% reduction). One year after the start of the experiment an isotopic labelling campaign with 13CO2 was conducted to trace the natural pathway of photosynthetic assimilates into above- and belowground carbon pools and fluxes.

During the first growing season of the experiment, severe drought more than doubled the growth of fine roots when compared to the control treatment. In turn, the mean diameter of the fine roots significantly decreased by 22%, and fewer ectomycorrhizal root tips were observed. These findings suggest that trees exposed to drought invest more in within-plant carbon maintenance and in the growth of root systems, rather than in the allocation of carbon to sustain the biology in the rhizosphere for nutrient acquisition. Moreover, post-label soil pore 13CO2 concentrations and total soil CO2 concentrations were lower under severe drought compared to intermediate and control treatments, indicating a generally reduced carbon metabolism. By tracking the fate of 13C assimilates into fine roots, soils and microbial communities over time we now investigate whether there is a threshold at which Scots pine trees stop investing in providing carbon to the rhizosphere and rather succumb to drought.
Comparison of NINO1+2 and NINO3.4 indices in terms of ENSO effects over the Euro-Mediterranean Region
Authors: Yavuzsoy Ece , Ezber Yasemin , Sen Omer Lutfi
Published: March 2021

El Nino Southern Oscillation (ENSO) is a phenomenon in the equatorial Pacific that could have profound effects on climate around the world. Although ENSO impacts are fairly well-defined for south and north America, Australia and south-eastern Asia, they are not very clear for Euro-Mediterranean region. Some studies indicate that the negative phase of ENSO in Nino3 and Nino3.4 indices have similar effects in the negative phase of North Atlantic Oscillation (NAO).  ENSO impacts and teleconnection patterns are mostly studied using the Nino3.4 index. However, some recent studies indicate that the Nino1+2 index has higher correlation with climate variability over the Euro-Mediterranean region.

In this study, we investigate impacts of ENSO over the Euro-Mediterranean climate variability and atmospheric dynamics using the Nino1+2 and Nino3.4 indices. Additionally, we also tried to understand if there is any relation between ENSO and the Mediterranean and East Asian troughs. NCEP/NCAR Reanalysis surface air temperature, precipitation and 500 hPa geopotential height datasets and SST-based ENSO indices from ERSSTv4 were used in the analysis for boreal winter (December-January-February) for a period of 1950 - 2019. We utilized the Pearson correlation analysis to reveal the relation between these indices and climate parameters and the composite analysis  to define the pattern differences between the cold and warm phases of the indices.

Our preliminary findings show that there is a distinct correlation pattern between Nino indices and surface air temperature over the region of interest. Nino1+2 index has a more distinct dipole pattern with a significant positive correlation pole over central Europe and negative pole over north-eastern Africa. However, Nino3.4 indicates a rather zonal correlation dipole pattern whose poles are over northwest Africa (strongly positive) and northeast Africa (negative). It is also found that the Mediterranean trough location is sensitive to the phase of ENSO for both indices. Namely, the Mediterranean trough tends to be in the west of its climatological location for La Nina phases of Nino1+2 and Nino3.4, which affects the distribution of surface temperature and precipitation over the Euro-Mediterranean and Middle East and Northern Africa (MENA) regions. We concluded that the La Nina phase of Nino1+2 seems to play a more distinctive role in the dipole pattern. The surface air temperature is colder over the entire Europe while it is opposite in the Middle East region including Turkey. This dipole pattern is also detected for the La Nina phase of Nino3.4, but it is mostly observed over southwestern Europe and northern Africa. Comparison between the La Nina and El Nino phases of the Nino1+2 index indicates that for the La Nina phase precipitation is larger over the Aegean Sea and Italy and smaller in northern Europe.
Physical processes behind interactions of microplastic particles with ice
Authors: Chubarenko Irina
Published: March 2021

Microplastic particles (MPs) are found in marine ice in larger quantities than in seawater, indicating that the ice is an important link in the chain of spreading of this contaminant. Some studies indicate larger MPs abundance near the ice surface, while others did not find any consistent pattern in the vertical distribution of MPs within sea ice cores. We discuss physical mechanisms of incorporation of MPs in the ice and present the results of laboratory tests, underpinning our conclusions.

First, plastic hydrophobicity is shown to cause the effect of pushing the floating MPs further up of the newly-forming ice. This leads to a concentration of MPs at the ice surface in the laboratory, while in the field the particles at the surface may by covered by snow and become a part of the upper ice layer. Under open-air test conditions, the bubbles of foamed polystyrene (density 0.04 g/cm3), initially floating at the water surface, were gone by weak wind when the firm ice was formed.

Second, the difference between freshwater and marine ice is considered. Since fresh water has its temperature of the density maximum (Tmd=3.98 C) well above the freezing point (Tfr=0 C), the freshwater ice is formed when the water column is stably stratified for a relatively long period of cooling from the Tmd down to the Tfr. Under such steady conditions, even just slightly positively/negatively buoyant MPs have enough time to rise to the surface / to settle to the bottom. In contrast, the ice in the ocean freezes when thermal convection is at work, further enhanced by the brine release. Thus, strong convection beneath the forming marine ice keeps slightly positively/negatively buoyant MPs in suspension and maintains the contact between the MPs and the forming ice. Laboratory tests show both the difference between the solid-and-transparent freshwater ice and the layered, filled with brine marine ice, and the difference in the level of their contamination.

Lastly, it is demonstrated that MPs tend to be incorporated in the ice together with air bubbles and in-between the ice plates (in brine channels). This is most probably due t plastics’ hydrophobicity.

Investigations are supported by the Russian Science Foundation, grant No 19-17-00041.
Storm Time EMIC Waves Observed by Swarm and Van Allen Probe Satellites
Authors: He Yangfan , Wang Hui , Hermann Lühr , Lynn Kistler , Anthony Saikin , Eric Lund , Ma Shuying
Published: March 2021

The temporal and spatial evolution of electromagnetic ion cyclotron (EMIC) waves during
the magnetic storm of 21–29 June 2015 was investigated using high-resolution magnetic field observations
from Swarm constellation in the ionosphere and Van Allen Probes in the magnetosphere. Magnetospheric
EMIC waves had a maximum occurrence frequency in the afternoon sector and shifted equatorward during
the expansion phase and poleward during the recovery phase. However, ionospheric waves in subauroral
regions occurred more frequently in the nighttime than during the day and exhibited less obvious
latitudinal movements. During the main phase, dayside EMIC waves occurred in both the ionosphere
and magnetosphere in response to the dramatic increase in the solar wind dynamic pressure. Waves were
absent in the magnetosphere and ionosphere around the minimum SYM-H. During the early recovery
phase, He+ band EMIC waves were observed in the ionosphere and magnetosphere. During the late
recovery phase, H+ band EMIC waves emerged in response to enhanced earthward convection during
substorms in the premidnight sector. The occurrence of EMIC waves in the noon sector was affected by
the intensity of substorm activity. Both ionospheric wave frequency and power were higher in the summer
hemisphere than in the winter hemisphere. Waves were confined to an MLT interval of less than 5 hr with a
duration of less than 186 min from coordinated observations. The results could provide additional insights
into the spatial characteristics and propagation features of EMIC waves during storm periods
Applying land use logistic regression models to assess different levels of air quality and to determine key environmental factors in Taiwan
Authors: Jang Cheng-Shin
Published: March 2021

Due to fast industrialization and urbanization, air pollution is more and more serious in Taiwan. Generally, many anthropogenic factors can affect air quality; for example,  exhaust gas from automobiles and motorcycles, factory emissions, fossil fuels, burning straw, incinerators, etc. The factors are highly associated with land use. Previous studies typically used multiple linear regression model to analyze the relationships between air quality and land use. This study adopts multi-threshold land use logistic regression (LULR) models with several continuous and categorical variables to assess different levels of fine particulate matters (PM2.5) in Taiwan and to determine key land-use factors controlling various levels of air PM2.5 pollution. First, data on annual air PM2.5 pollution in the Taiwan Island are collected in 2017. Four thresholds of 16.37, 18.68, 21.83, 25.83 µg/m3 are determined based on the 20th, 40th, 60th, and 80th percentiles, respectively, of observed data. Geographical information system is then adopted to analyze data on 29 environmental variables obtained from the three main dimensions–information of land-use categories, amounts of specified pollution sources in townships, and geographical locations adjacent to monitoring stations of air quality. Finally, data in 2017 are employed to establish the LULR model and significant land-use factors causing air PM2.5 pollution are determined using stepwise LULR models for various levels of air PM2.5 pollution. Moreover, data in 2018 are used to verify the established LULR models. The analyzed results reveal that correct responses of the LULR models range from 83.6% to 100%. For the 20th-percentile threshold, locations and the industry land-use area are positively contributed to air pollution, while tempt densities and building, agriculture, forest land-use areas are negatively contributed to air pollution. For the 40th-percentile threshold, locations, plains with an elevation of less than 150 m, and agriculture land-use areas are related to air pollution. For the 60th-percentile threshold, locations are positively related to air pollution, while forest land-use areas are negatively related to air pollution. For the 80th-percentile threshold, locations and industry park areas associated with air pollution. According to the research results, a feasible strategy of environmental management and outdoor activities is proposed.
Crustal structure of Khorasan (E-NE Iran) using the Rayleigh wave tomography
Authors: Rezaei Maryam , Shirzad Taghi
Published: March 2021

Classical surface wave tomography based on waveform scattering through seismic data has an important role in studying the structure of the Earth‘s crust and upper mantle on regional and global scale. The shallow crustal velocity structure is studied using earthquake waveforms in Khorasan/E-NE Iran. For this purpose, 522 local recorded waveforms with M≥4, which occurred between 53°-63°E and 30°-42°N, were selected. Therefore, all available vertical components of waveforms recorded at the stations in the Iranian Seismological Center (IrSC), the International Institute of Earthquake Engineering and Seismology (IIEES), and the IRIS global network collected in the period between January 2006 to October 2020. Then, some data selection criteria were applied for each waveform, including (i)SNR>4, (ii) the gap time less than 2 s within the expected signal window (1.5-4.5 km/s), (iii) epicentral distance greater than 20 km. The multiple-filter analysis technique was then applied by the computer program in seismology Hermann and Ammon (2013) to measure Rayleigh wave dispersion curves in the period range of 3-50 s. Finally, Rayleigh wave 2D horizontal group velocity maps are calculated by the fast marching surface wave tomography method. Our tomographic results indicate some local low velocity anomalies appeared in the W-NW of the study area where it connected with the East-Alborz tectonic structure. Also, the Doruneh Fault System clearly separates Kopeh-Dagh tectonic zone and Central Iran micro-plateau. However, a high velocity anomaly appears in Kopeh-Dagh tectonic zone at periods larger than 16 s and 30 s.
Compound heat and ozone pollution events relevant for human health
Authors: Hertig Elke , Russo Ana , Trigo Ricardo
Published: March 2021

Temperature extremes and air pollution pose a significant threat to human health. A specific concern applies to heat events and elevated ground-level ozone concentrations, due to the physical relationships between these variables, the single and combined effects of both variables on human health and the anticipated substantial changes in the scope of climate change.

The present contribution addresses relationships between air temperature and ground-level ozone, the association of these variables with atmospheric circulation patterns, the anticipated changes under future climate change as well as their association with human morbidity (i.e. myocardial infarction frequencies, Hertig et al. 2019) and mortality. The focus is on two climatically different regions in Europe, i.e., Bavaria (Central Europe) and Portugal (South Europe).

In general, a strong relationship between air temperature and ozone formation became evident. Due to the non-linear nature of the relationship, higher temperatures usually led to substantially enhanced ozone concentrations. In the scope of climate change, considerable increases of maximum temperatures were assessed for Bavaria until the end of the century. Also, future ozone concentrations were projected to rise (Hertig 2020). With respect to spell-length related extremes (heat waves and/ or ozone pollution waves), heat waves were identified as the most frequent wave type for the two European regions under investigation. Waves were associated with in-situ built-up as well as with advection of air masses. Despite different climate settings, a comparable exposure to heat and ozone waves was found in Central and South Europe. In view of excess mortality, the most severe impacts were always associated with compound heat-ozone waves (Hertig et al. 2020).

Research was supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under project number 408057478.

Hertig, E., Russo, A., Trigo, R. (2020): Heat and ozone pollution waves in Central and South Europe- characteristics, weather types, and association with mortality. Atmosphere. doi: 10.3390/atmos11121271

Hertig, E. (2020): Health-relevant ground-level ozone and temperature events under future climate change using the example of Bavaria, Southern Germany. Air Quality, Atmosphere and Health. DOI: https://doi.org/10.1007/s11869-020-00811-z

Hertig, E., Schneider, A., Peters, A., von Scheidt, W., Kuch, B., Meisinger, Ch. (2019): Association of ground-level ozone, meteorological factors and weather types with daily myocardial infarction frequencies in Augsburg, Southern Germany. Atmos. Environment. DOI: 10.1016/j.atmosenv.2019.116975
Humidity-dependence of Climate Sensitivity
Authors: Bourdin Stella , Kluft Lukas , Stevens Bjorn
Published: March 2021

We study how the vertical distribution of relative humidity (RH) affects climate sensitivity (CS), even if it remains unchanged with warming. Using a one-dimensional radiative-convective equilibrium model, konrad, we show that the climate sensitivity depends on the shape of the vertical distribution of humidity, an effect we call humidity-dependence: Moister atmospheres were shown to have a larger CS, increasingly so with warmer temperature, consistent with our understanding of how water vapor influences the transmissivity of the atmospheric window (Nakajima et al., 1992; Koll & Cronin, 2018). CS is further shown to increase with increasing humidity in the upper troposphere but decreases with increases in humidity in the lower mid-troposphere. We interpret these effects in terms of the effective emission height of water vapor. Differences in the vertical distribution of RH are shown to explain a large part of the 10 to 30% differences in clear-sky sensitivity seen in climate and storm-resolving models. The results imply that convective aggregation reduces climate sensitivity, even when the degree of aggregation does not change with warming. Combining our findings with relative humidity trends in reanalysis data shows a tendency toward Earth becoming more sensitive to forcing over time. These trends and their height variation merit further study.