bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological Characteristics and Elemental Composition of Magnetic Minerals from the Volcanic Activity of Lake Maninjau Sediments
Authors: Prasetyo Ihsan Junira , Rifai Hamdi , Syafriani Syafriani , Putra Rizaldi
Published: March 2022

Lake Maninjau has formed by the eruption of the Maninjau volcano, which spewed volcanic material to various places. This volcanic material contains various mineral-forming elements, one of which are magnetic minerals that accumulate in lake sediments. This research aims to determine the morphological characteristics and composition of magnetic mineral elements from volcanic activity in the sediments of Lake Maninjau, Agam Regency, Indonesia. Characteristics of morphological and composition of magnetic mineral elements originating from volcanic activity can describe volcanic eruptions in the past. So, this research is very important for paleo-eruption studies because it can be used as supporting information to determine the distribution of volcanic ash from a volcanic eruption in the past based on the magnetic properties of the material. The sample was selected from the core MAN 18-41B site 12 with a depth of 35 - 36 cm because it has a high magnetic susceptibility value. Morphological images of lake sediment magnetic minerals were viewed using a SEM instrument and EDS detector that shows the composition of the elements that arrange magnetic minerals. In general, the analysis of morphological images shows that the magnetic mineral grains in the Maninjau lake sediments are irregular and porous. This indicates that the magnetic minerals originate from volcanic activity. The image produced by Back Scattered Electron (BSE) has a difference in brightness on the surface of the magnetic grains, which indicates that the bright surface contains high Fe elements and the dark surface contains high Si. The spectrum generated by EDS shows that the dominant elements present in magnetic minerals in lake sediments are Fe, Ti and Si. Based on the morphology and elemental composition, it is indicated that the minerals contained in the sediments of Lake Maninjau come from volcanic activity.

HIGHLIGHTS

Lake Maninjau has formed by the eruption of the Maninjau volcano, which spewed volcanic material to various places. This volcanic material contains various mineral-forming elements, one of which are magnetic minerals that accumulate in lake sediments

Characteristics of morphological and composition of magnetic mineral elements originating from volcanic activity can describe volcanic eruptions in the past

Morphological forms can provide information about the source of magnetic minerals derived because magnetic minerals have different properties, types, and morphology depending on the source

Maninjau Lake sediments are dominated by Iron (Fe), Silica (Si), and Titanium (Ti). Based on the morphological images and elemental composition, the magnetic minerals present in the Maninjau lake sediments are indicated to come from volcanic activity

GRAPHICAL ABSTRACT
Key Learnings from Pre-Silicon Safety Compliant Bootrom Firmware Development
Authors: Baskaran Chidambaram , Nayak Pawan , Manoj R. , Shantanu Sampath , Aravindhan Karuppiah
Published: March 2022

Safety needs of real-time embedded devices are becoming a must in automotive and industrial markets. The BootROM firmware being part of the device drives the need for the firmware to adhere to required safety standards for these end markers. Most software practices for safety compliance assume that software development is carried out once the devices are available. The BootROM firmware development discussed in this paper involves meeting safety compliance need while device on which it is to be executed is being designed concurrently. In this case, the firmware development is done primarily on pre-silicon development environments which are slow and developers have limited access. These aspects present a unique challenge to developing safety compliant BootROM firmware. Hence, it is important to understand the challenges and identify the right methodology for ensuring that the firmware meets the safety compliance with right level of efficiency. The authors in this paper share their learnings from three safety compliant BootROM firmware development and propose an iterative development flow including safety artefacts generation iteratively. Concurrent firmware development along with device design may sound risky for iterative development and one may wonder it may lead to more effort but the learnings suggests that iterative development is ideal. All the three BootROM firmware development has so far not resulted in any critical bugs that needed another update of the firmware and refabrication of the device.
Islamic students’ attitudes and perceptions toward learning English: a study from male-female students of STIT Madani Yogyakarta
Authors: Dhian Marita Sari
Published: March 2022

The English status of a Foreign Language (FL) in Indonesia has been granted. However, the language has become quite popular and dominant in several schools in Indonesia, especially in private colleges and universities. The study aimed was to find out the male-female English foreign language (EFL) students’ attitudes and perceptions toward learning English and female and male students’ difficulties in learning English. The data was collected from 30 Islamic at the first student’s semester at STITMA Yogyakarta. Data collecting techniques used in this research were through a set of close-ended questioners. The study used a qualitative and quantitative resign design. The research finding revealed that male and female Islamic education students have positive attitudes and perceptions to learn English although the male students had lower enthusiasm to gain their knowledge in learning English than female students. Both (male and female students) perceived learning English was important not only for their future life but also for spreading Islam around the world. The female and male students had similar obstacles in pronunciation and vocabulary mastery. Moreover, most female students thought that speaking skills were the most difficult skill, while most male students consider listening was the most difficult skill to learn.
MODERN APPROACHES TO THE STUDY OF BIOLOGY IN THE STEM EDUCATION CENTERS
Authors: Zaderey N. S.
Published: March 2022

The new challenges set before modern society require a rethinking of approaches to the learning process and require training young people in new curricula aimed at training generalists, whose deep theoretical knowledge will be supported by practical skills. In 2016–2018, the Ministry of Education and Science of Ukraine adopted a number of orders that ensured the formation of a new approach to the educational process in Ukraine. STEM education was introduced, which should support students theoretical knowledge gained during the school process, practical skills, obtained through the practical activities of children in specialized centers equipped with the necessary equipment. In August 2018, on the basis of the communal institution Richelieu Lyceum, an experimental educational and scientific subdivision “Center for STEM-education of Odessa region” was created. In the center of STEM-education in Odessa region, work is underway to introduce new teaching methods, which include mandatory practical work of students in the classroom. In connection with the need to devote more time to the lesson for students to perform practical work on this topic, the methodologists of the STEM-center develop special training programs for students. For students of Richelieu Lyceum attending the STEM-center are offered such electives in the profile “Biology” as: levels of organization of living matter, modern taxonomy of living organisms, human pathophysiology, biotechnology: cell and genetic engineering, laboratory work and others. The educational process is necessarily accompanied by practical work involving microscopes. Individual work of students with microscopes improves the level of knowledge acquired by the child; gives them the opportunity to obtain visual confirmation of the theoretical material that was learned during the lesson; provides the formation of research skills; increases their overall self-esteem and provides further growth of interest in the educational process. Acquisition of practical work skills increases the level of preparation of students and provides them with the opportunity to participate in various competitions, Olympiads, tournaments, defense of scientific papers.
INTERNET RESOURCES IN RESEARCH ACTIVITY TEENAGERS
Authors: Postova K. H.
Published: March 2022

The article reveals the urgency of using Internet resources in the research activity of teenagers. The main directions of the study of the problem of informatization of education also the use of information resources in research activities. The place of Internet resources in the structure of information resources and in the system of informational of education is defined. The analysis of Internet resources is conducted and the necessity of their use is determined. The possibilities of using the Internet resources at different stages of preparing the research work of schoolchildren are shown. The possibilities of a differentiated approach in the use of Internet resources in the research work of schoolchildren are explored. Methodical recommendations on the organization of scientific research work using Internet resources have been developed. Prospects for the development and use of some Internet resources, such as digital libraries, online laboratories, virtual museums, have been identified. The methods of working with each of the types of resources in the process of solving the research problem are described. In detail, the use of online libraries at the stage of choosing the problems of research also theoretical study of the problem. The use of virtual museums as a motivation for adolescents to research. The functions of virtual laboratories are considered on the stage of experimental testing of the hypothesis in research work. The possibilities of some Internet resources in certain areas of knowledge are highlighted, namely: biology, physics, mineralogy, culturology, art. Examples are given of the use of electronic libraries, virtual museums, virtual laboratories in the research activities of adolescents. The role of the supervisor in the organization of work with Internet resources in the process of research is identified.
OVERVIEW OF NON-COGNITIVE FACTORS OF LEARNING
Authors: Safonova H. F. , Vichna O. V. , Safonov M. S.
Published: March 2022

The article discusses non-cognitive factors of learning, and how they can seriously affect student performance. Among the considered non-cognitive factors are: growth mindset, belonging and academic persistence and other personal qualities. Possible psychological interventions are described, which help to eliminate the influence of some negative factors. In particular, such as fixed mindset by replacing it with growth mindset. There are two ways in which teachers can solve social problems such as: belonging and stress. As well as helping to address students’ concerns about bias and unfair feedback. It is shown how the fear of students’ mistakes can significantly slow down their development process. And self-regulation skills have a strong positive correlation with learning outcomes. The approach of strengthening students’ sense of purpose by targeting their future image is considered. It is emphasized that psychological interventions will be effective only if they are implemented in ways that can significantly and effectively change the way students think about themselves, their group, their work. In addition, these interventions must be subtle and varied. And teachers should not only observe the group environment and the interactions that occur there, but also consider how these elements are interpreted by students. The most common mistakes that teachers make are highlighted and suggested how to avoid them. It encourages students to persevere because of failures only by offering to try again; psychological interventions as general, universal occupations; overestimation of students’ efforts. It is also noted that the way of thinking does not ensure academic success, so psychological interventions should be integrated with academic to improve both motivation and learning outcomes of students.
Avrupa Birliği (AB) Üyesi Olmayan Bir NATO Üyesi Olarak Türkiye'nin Ortak Güvenlik ve Savunma Politikasındaki (OGSP) Rolü
Authors: BAYKARA Sıla Turaç
Published: March 2022

Avrupa güvenliği NATO için önemli bir faaliyet alanıdır ve NATO, AB’nin ortak güvenlik ve savunma politikası konusunda yaşadığı dönüşüme olumlu baktığını belirtmiştir. Fakat AB üyesi olmayan ama NATO üyesi olan Türkiye’nin durumu NATO-AB ilişkilerinde iş birliğinin yanı sıra çatışmanın da başlaması açısından bir dönüm noktası olmuştur. Türkiye ise, Soğuk Savaş döneminde değerli bir ortak olmasına, NATO'da kilit bir rol oynamasına ve Soğuk Savaş sonrası dönemde bir dizi güvenlik operasyonuna, barışı koruma misyonlarına ve korsanlık ve terörle mücadele çabalarına katkıda bulunmasına rağmen, AB ile arasında güvensizlik ortamı yaratan Kıbrıs Rum Yönetimi ve AB üyeliğinin olmaması nedeniyle ayrımcı AB politikalarına maruz kalmaktadır. Bu çalışma, NATO üyesi olan Türkiye’nin AB’nin OGSP ile ortak bir çalışma zemin bulma olasılığının olup olmadığını irdelemeye çalışmaktadır. Çalışmada, Türkiye'nin NATO ve AB kapsamında yürütülen barışı koruma askeri ve sivil misyonlarına nasıl başarılı bir şekilde katkıda bulunduğu ve 2011’den sonra düşüş göstermiş olsa da OGSP ile yıllardır nasıl uyum içinde olduğu sonucuna varılmıştır.
A dual stable isotope and radiocarbon approach for apportionment of aerosol sources
Authors: Bučinskas Laurynas , Garbarienė Inga , Šapolaitė Justina , Ežerinskis Žilvinas , Garbaras Andrius
Published: March 2022

Various natural and anthropogenic activities generate atmospheric sulfur and carbon aerosol which in turn has an adverse effect on human health, climate change and visibility [1], [2]. Man-made sources of aerosol include power plants, vehicular traffic, domestic heating, biomass burning and other industrial emissions. The stable isotope ratio analysis of bulk aerosol material provides valuable information on the origin of its constituents but a combination of stable isotope and radiocarbon techniques allows for an even greater level of differentiation [3].

The aim of this work was to employ stable carbon and sulfur isotope ratio analysis together with radiocarbon data in apportionment of aerosol sources. The collection of aerosol PM1 samples was performed in Vilnius, Lithuania during a period of 5 months. Stable isotope δ34S and δ13C values were measured with a stable isotope mass spectrometer and 14C measurements were done using a single stage accelerator mass spectrometer. Simple isotope mixing equations were applied to stable isotope and radiocarbon data to distinguish inputs of biomass, traffic and coal sources of carbonaceous aerosol. By comparing calculated source fractions to δ34S values we find that biomass and coal combustion were dominant sulfur aerosol pollutants. In addition, average contributions of coal and fossil combustion, biogenic, soil emissions to sulfate aerosol were evaluated. Finally, the preceding results together with total carbon and sulfate concentrations were related to HYSPLIT air mass back trajectory plots. Such an approach allows for a comprehensive description of sulfur and carbon aerosol pollution sources.

 

[1]          C. A. Pope and D. W. Dockery, "Health effects of fine particulate air pollution: Lines that connect", J. Air Waste Manag. Assoc., t. 56, nr. 6, 2006.

[2]          C. Tomasi, C. Lanconelli, M. Mazzola and A. Lupi, "Aerosol and Climate Change: Direct and Indirect Aerosol Effects on Climate", Atmospheric Aerosols, 2016.

[3]          I. Garbarienė et al., "Origin identification of carbonaceous aerosol particles by carbon isotope ratio analysis", Aerosol Air Qual. Res., 2016.
A Case Study of Extreme Weather Shock and Warfare: The Fall of the Kingdom of Israel c.720 BCE
Authors: Kostick Conor
Published: March 2022

The idea that warfare increases when societies are subject to stress from climate extremes is plausible and yet has not been definitively established. Were it to be so, then the possibility of outbreaks of warfare, particularly between nations capable of bringing about unprecedented levels of destruction, would be one of the greatest risks for those living in an age of extreme climate events. As a contribution to the contention that there is a connection between extreme climate events and outbreaks of warfare, this paper offers a case study of the fall of the Kingdom of Israel c. 720 BCE with the conquest of the city of Samaria by Assyria. Because of the religious significance of the event, the defeat of the ancient Kingdom of Israel has been a subject of considerable study, despite the paucity of the sources. Until now, there has been no exploration of the role of climate extremes in the events of the period, other than to reject the idea that climate had any impact on the issue, as one scholar has written: 'no specific impulses from a (sudden) change in climate would have influenced the course of events leading to the end of the kingdom.’

This paper will draw on recent ice-core data to connect the fact that there was a very significant volcanic eruption in 723 BCE with the political and military events of the years immediately following. It will argue that a severe drop in temperature had a powerful impact on societies with relatively frail resilience to such shocks and that the stress created by the volcanic climate event had a profound effect on the decision makers of the era, with disastrous consequences in the case of the Kingdom of Israel.
Finite-Frequency Body-Wave Tomography in Scandinavia
Authors: Bulut Nevra , Thybo Hans
Published: March 2022

We present a P-wave velocity model of the upper mantle, obtained from finite-frequency body wave tomography, to analyze the relationship between deep and surface structures in Fennoscandia, one of the most studied cratons on Earth. The large array aperture of 2000 km by 800 km allows us to image the velocity structure to 800 km depth at very high resolution. The velocity structure provides background for understanding the mechanisms responsible for the enigmatic and debated high topography in the Scandinavian mountain range far from any plate boundary. Our model shows exceptionally strong velocity anomalies with changes by up to 6% on a 200 km scale. We propose that a strong negative velocity anomaly down to 200 km depth along all of Norway provides isostatic support to the enigmatic topography, as we observe a linear correlation between hypsometry and uppermost mantle velocity anomalies to 150 km depth in central Fennoscandia. The model reveals low velocity anomaly below the mountains underlain by positive velocity anomalies, which we explain by preserved original Svecofennian and Archaean mantle below the Caledonian/Sveconorwegian deformed parts of Fennoscandia. Strong positive velocity anomalies to around 200 km depth around the southern Bothnian Bay and the Baltic Sea may be associated with pristine lithosphere of the present central and southern Fennoscandian craton that has been protected from modification since its formation. However, the Archaean domain in the north and the marginal parts of the Svecofennian domains appear to have experienced strong modification of the upper mantle. A pronounced north-dipping positive velocity anomaly in the southern Baltic Sea extends below Moho. It coincides in location and dip with a similar north-dipping structure in the crust and uppermost mantle to 80 km depth observed from high resolution, controlled source seismic data. We interpret this feature as the image of a Paleoproterozoic boundary which has been preserved for 1.8 Gy in the lithosphere.
Seismic attenuation across the brittle-ductile transition
Authors: Natale Castillo Maria Aurora , Tesauro Magdala , Cacace Mauro , Passelegue Francois X. Thibault , Pimienta Lucas , Violay Marie
Published: March 2022

Rocks mechanical behaviour, and in particular, their transition from a brittle to a ductile deformation has been prevalently investigated through rheological experiments and numerical models. In conjunction with rocks mechanical studies, the analyses of seismic wave propagation can improve our knowledge of physical rocks behaviour and provide an alternative assessment of the brittle ductile transition (BDT).

In this study, we investigate the quantitative relationships between seismic attenuation and viscous rocks' rheology, especially across the BDT domain. For this purpose, we rely on the Burgers and Gassmann mechanical model to derive shear wave attenuation (1/Qs ), for several dry and wet crustal rheology, thermal conditions, and different strain rates values. This allows us to establish geothermal and mechanical conditions at which the BDT occurs and to cross-correlate this transition to computed shear seismic wave attenuation values. We observe that the variation with depth is related much more to the input strain rate than to the rock‘s rheology and thermal conditions, so that a fixed amount of Qs reduction can identify the average BDT depths for each strain rate used. Below the BDT depth, we observe a significant increase of the Qs reduction (up to 10-4 % of the surface value), depending also on rocks temperature and rheology. Since the greatest Qs reduction is estimated for the greatest input strain rate (10-13 s-1) and hot thermal conditions, the proposed method can find more applicability in tectonically active/geothermal areas.

We tested the obtained results by performing triaxial lab experiments, while monitoring ultrasonic P-waves, on a sample of Carrara marble, at ambient temperature and 180 MPa confining pressure. The transition from brittle to semi-brittle conditions is characterized by the increase of crack-density with a progressive rate reduction. At the same time, both the seismic velocity and energy significantly decrease during the first phase of deformation (brittle regime) and tend towards an asymptotic value, when the sample approaches the ductile deformation. We interpret the absence of an increase of energy loss at the BDT, as due to the persistent effect of the microfracturation. The last one usually accompanies the deformation mechanisms that occur at the BDT (e.g., pressure solution, twinning), masking the expected increase of attenuation at the beginning of the ductile conditions. This is a matter that still needs to be investigated.
Multi Scale Assimilation of NDVI and radar data for soil moisture and Leaf Area Index Predictions in an Heterogeneous Mediterranean Ecosystem 
Authors: Gaspa Andrea , Corona Roberto , Montaldo Nicola
Published: March 2022

In the presence of uncertain initial conditions and model parameters coupled land surface model (LSM)- vegetation dynamic model (VDM) performance can be significantly improved by the assimilation of periodic observations of certain state variables, such as the soil moisture and normalized difference vegetation index (NDVI) as observed from satellite remote platforms.

The possibility to merge grass and tree NDVI observations and radar data with the model optimally for providing robust predictions of soil moisture and grass and tree leaf area index (LAI) in heterogenous ecosystems is demonstrated. We propose an assimilation approach that assimilates backscatter data from radar and NDVI from optical sensors through the Ensemble Kalman filter (EnKF) and provides a physics-based update of soil moisture and grass and tree LAI predicted by VDM. We used Sentinel 1 radar data for soil moisture, and Landsat 8 and Sentinel 2 optical data for NDVI. Soil moisture is predicted by the LSM, while the VDM predicts the LAI, which is strictly related to NDVI, through a field-estimated empirical relationship.

This approach, as with other common assimilation approaches, may fail when key model parameters, e.g. the saturated hydraulic conductivity of LSM and the maintenance respiration coefficient (ma) of VDM, are estimated poorly. This leads to biased model errors producing a violation of a main assumption (model errors with zero mean) of the EnKF. For overcoming this model bias an innovative assimilation approach was developed, which accepts this violation in the early model run-times and dynamically calibrates all the components of the model parameter ensembles as a function of the persistent bias in soil moisture and LAI predictions, allowing to remove the model bias, restore the fidelity to the EnKF requirements and reduce the model uncertainty.

The proposed multiscale assimilation approach was tested in a Sardinian field site, a typical Mediterranean ecosystem characterized by strong heterogeneity of the vegetation and water limited conditions. The site is also a case study of the SWATCH European Research Project, and in this field a micrometeorological eddy-covariance based tower is operating from 2003.

The positive impact of the proposed assimilation approach on the soil water budget, evapotranspiration and CO2 uptake predictions in the heterogenous ecosystem is demonstrated finally. 
Ionospheric sounding experiment IONO onboard CubeSat INSPIRE-SAT 7
Authors: Galopeau Patrick H. M. , Meftah Mustapha , Keckhut Philippe , Grossel Kévin , Rannou Véronique , Boust Fabrice , Phan Huy Khang , Turpaud Vincent , Boudjada Mohammed Y. , Eichelberger Hans U.
Published: March 2022

INSPIRE-SAT 7 is a French 2 Unit CubeSat weighting approximately 3 kg, very similar to the satellite UVSQ-SAT which was launched on 24 January 2021. Its main purpose is the measurement of the Earth’s radiation budget at the top of the atmosphere and the sounding of the ionosphere. It will orbit at a maximum altitude of 600 km on a Sun-synchronous orbit with a descending node at ~0930 LT. The IONO experiment embarked on the CubeSat is dedicated to the sounding of the Earth’s ionosphere. The latter results from the ionization of the upper atmosphere due to UV radiations and X-rays coming from the Sun. The electron density in the ionosphere depends on the local time, the season, and the solar activity. The propagation of the radio waves is affected by the electron density and also by refraction and reflection phenomena. We consider the following goals for the IONO instrument: improving ionosphere models, in particular the IRI (International Reference Ionosphere); study of the propagation of electromagnetic waves in the ionosphere and the factors which can disturb it (e.g., thunderstorms); analysis of temporal and spatial variability at different scales; study of the coupling between ionosphere and magnetosphere, and the electrical circuit between ionosphere and lithosphere. The observations collected by IONO will be compared to those produced by a VLF-LF antenna network designed for investigating the perturbations of the ionosphere, and the wave propagation, by seismic phenomena.
How do arbuscular vs. ectomycorrhizal trees and site-specific variations affect soil organic matter pools?
Authors: Koplitz-Weissgerber Andrea , Vidal Alix , Mueller Carsten W. , Bruegger Franz , Netherway Tarquin
Published: March 2022

The type of tree mycorrhizal association, together with the leaf type of the host, can influence carbon (C) pools and thus potentially C persistence in forest soils. In arbuscular mycorrhizal (AM) systems, litter tends to decompose rapidly with high C mineralization, thus favoring the formation of mineral-associated organic matter (MAOM). In ectomycorrhizal (EcM) systems, the litter decomposition is slower, which tends to result in the accumulation of particulate organic matter (POM). Yet, the effect of different mycorrhizal types associated with broadleaf trees on soil organic matter pools, and especially different fractions of POM (free: fPOM and occluded: oPOM), have rarely been explored. We quantified and characterized the soil organic matter (SOM) fractions within AM-associated and EcM-associated systems, on various sites. We collected soil samples (1-10 cm) on four sites in Sweden. Each site included broadleaf EcM-associated trees (Betula pendula), AM-associated trees (Fraxinus excelsior), and crop fields. We combined density and soil particle size fractionation to separate the soil into five organic matter (OM) fractions: fPOM, oPOM, oPOMsmall (< 20 µm), MAOM (> 53µm), and MAOMsmall (< 53 µm). We measured the C and N content, as well as δ13C values in all soil fractions and characterized the chemical composition of the POM fractions using 13C CP-MAS NMR spectroscopy. We also analyzed the fungal communities in the bulk soil using a sequencing approach.  As expected, forest soils contain higher amounts of POM, especially fPOM, than crop field soils. The fPOM in crop fields was less decomposed as in forest soils, as reflected by the lower alkyl C : O/N alkyl C ratio in the NMR spectra. Regardless of the vegetation and mycorrhizal types, the four sites presented oPOM and fPOM with similar chemical characteristics. Yet, the chemical composition of oPOMsmall varied across sites, as reflected by contrasting alkyl C : O/N alkyl C ratio. While the vegetation type (forest versus crop field) tends to be an essential driver of SOM fraction mass distribution, site-specific variations, rather than vegetation and mycorrhizal types, seem to drive the chemical composition of oPOMsmall fractions. As fungi are key decomposers of SOM we expect that differences in SOM fractions between vegetation types and sites will also be reflected in different fungal communities. However, we expect that differences in fungal communities between mycorrhizal types and vegetation types will be larger than between sites.
Correlation of Meteorological and Hydrological Droughts using Observational and Modelled Data in the Guadalquivir River Basin
Authors: Romero-Jiménez Emilio , García-Valdecasas Ojeda Matilde , Yeste Patricio , Rosa-Cánovas Juan José , Esteban-Parra María Jesús , Castro-Díez Yolanda , Gámiz-Fortis Sonia R.
Published: March 2022

Future scenarios of climate change foresee an increase in frequency, duration, and severity of droughts, especially in arid and semiarid regions. This predictions require an intensive study of drought mechanics, starting with how past and present droughts behave, and continuing with the study of future droughts.
In this research, it has been studied how a precipitation decrease that causes a meteorological drought is related to hydrological drought, caused by a decrease in river streamflow. The area of study is located in the Guadalquivir River basin, south of the Iberian Peninsula, which serves as an example of semiarid region. Two different sources of streamflow data are used: observational data obtained from the Spanish Centre for Public Work Experimentation and Study (CEDEX), which takes into consideration regulation from reservoirs, and modelled data obtained with the Variable Infiltration Capacity (VIC) model. The use of two data sources allows for a comparison of results, serving as a validation for future projects that will rely on the use of modelled data to study the behaviour of droughts in the near future.
The numerical description and correlation of droughts is performed by means of drought indices, such as the Standardized Precipitation Evapotranspiration Index (SPEI) or the Standardized Streamflow Index (SSI), each describing one drought type, respectively meteorological and hydrological.

Keywords: Drought indices, Hydrological model, Observational data, Guadalquivir basin.

Acknowledgements
This work was funded by FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento, project B-RNM-336-UGR18, by the Spanish Ministry of Economy and Competitiveness project CGL2017-89836-390 R with additional support from FEDER Funds, and by FEDER/Junta de Andalucía-Consejería de Transformación Económica, Industria, Conocimiento y Universidades (project P20_00035).
Survival of ice nucleating bacteria in freezing cloud droplets
Authors: Kiselev Alexey A. , Wieber Corina , Rabe Kersten , Zoheir Ahmed , Leisner Thomas
Published: March 2022

The widespread plant pathogenic bacteria Pseudomonas Syringae are one the most efficient ice nucleating organisms found in the atmospheric clouds. Various strains of P. Syringae have been identified not only in agricultural regions and on the plant leaves, but also in the samples of cloud water and in fresh snow and rain collected far away from the ecosystems of origin.

Not only P. Syringae survive the transport over several hundred kilometers, they are also able to multiply in the cloud droplets. At low temperature, bacteria initiate the freezing of the supercooled water droplet owing to the ice nucleation active (INA) protein molecules anchored on the outer shell of the cell membrane. As liquid water converts to ice, ice crystals grow fast via water diffusion and droplet coalescence, finally returning to the ground as rain or snow.

How do microorganisms survive the freezing of the cloud droplets? Under what conditions are their chances of survival highest, and which factors play the most important role? We address these questions by freezing microscopic water droplets containing P. Syringae levitated in an electrodynamic trap under realistic cloud conditions and observing the freezing events with a high-speed video camera. The droplets are then extracted from the trap and transferred to a Petri dish containing nutritious media, where the number of surviving bacteria is determined by colony counting. We find that the P. Syringae bacteria have a good chance of survival especially if the freezing of the drops takes a lot of time and the bacteria are able to adapt to the new conditions. At low ambient temperature, the bacteria counteract rapid freezing by initiating ice nucleation at low supercooling, highlighting the role of the INA proteins in the survival mechanism.  By modelling the water flow through the cell wall during freezing numerically, we demonstrate that the permeability of the bacteria cell membrane plays a decisive role in the fight for survival in a freezing environment. Thus, we suggest an explanation of the bacteria survival mechanism based on the thermodynamic model.
Effect of Extreme Climate Change on Reservoir Water Quality and Watershed Hydrology in Humid Subtropical Climate Zone
Authors: Lin Yu-I , Pan Shu-Yuan
Published: March 2022

Climate change, such as the increased frequency of extreme droughts, alerts the security of water supply and storage in many regions around the world. Despite this fact, only a few studies on evaluating the effects of drought on water quality in Asia were published over the past decade. In 2021, Taiwan (an island in humid subtropical climate region of east Asia) faces its most severe water crisis in the past fifty years, and the Te-Chi reservoir is one of the most affected regions due to the remarkable hydrologic variability. In this study, we first investigated the climate and hydrological data to evalaute the effect of the climate change on the water quailty of the Te-Chi reservoir. The results showed that the annual average temperature in this area risen by about 1.3 °C, while a declining trend in total annual rainfall was observed over the past 15 years. Particularly in recent years (for instance from October 2020 to May 2021), the water storage capacity of the Te-Chi reservoir continuously declined from 66.5% to 1.1%. Also, we found that the concentration of total phosphorus, total nitrogen and electrical conductivity in Te-Chi reservoir tended to increase, while the transparency of water decreased. In contrast, monsoons and typhoons in June-July 2021 have replenished the reservoir (i.e., back to 90% of the total water storage capacity). However, the concentration of total phosphorus and Chlorophyll-a incresed accordingly, which migh be attributed to the non-point source contributions such as agricultural surface runoffs. We also analyzed the variance of water quality parameters with multivariate statistics methods. We found that water quality parameters of reservior was significantly influenced by the extreme weather, which would frequently occur in the future. In other words, continuous multicriteria-based analyses on water quality monitoring are needed for sustainable reservoir operation.
Atmospheric Abundance Of EC, OC And WSOC During Day And Night Time At An Urban Site Of Bihar State (INDIA)
Authors: Roy Akanksha
Published: March 2022

Fossil fuel emissions contribute huge amount of carbonaceous aerosols into the air which plays an important role in the climate change. The carbonaceous aerosol especially organic carbon (OC) and elemental carbon (EC) affect radiative forcing of the Earth. Therefore, the present study was carried out at an unexplored urban site in Saharsa district of Bihar state in India. The aerosol samples were collected during monsoon period (June-September 2019) to study day and night time variation of OC, EC and water soluble organic carbon (WSOC). The average concentration of EC during day time was noticed as 6.8 µg/m3 while during night time as 8.5 µg/m3. The average concentration of OC during day time was noticed as 9.1 µg/m3 while during night time as 13.7 µg/m3. On an average the night time concentrations of OC and EC were almost 25% higher than their day time concentrations. . The concentration of fine particulate matter was found to be higher during the night time as compared to the day time. OC/EC ratios were relatively lower than the standard value considered for biomass burning as a sources which suggested that the sources were mostly of fossil fuel burning type, probably thermal power plant and automobile exhaust. The average ratio during day time and night time was noticed to be 1.45 and 1.65 suggesting the dominance of EC which also indicated fossil fuel burning, the major source of carbonaceous aerosol at the site. The average WSOC/OC ratio was found to be same during both day and night time due to the formation of secondary organic aerosols. The average concentration of total carbonaceous aerosols accounted for about 24% of the total fine particulates during day time and about 18% of the total fine particulates during night time indicating more prominent carbon emission activity during day time.

Keywords: Carbonaceous Aerosol, Organic Carbon, Elemental Carbon, WSOC, Total Carbonaceous Aerosols.

 
Temporal evolution of melt composition during the 2021 Cumbre Vieja eruption
Authors: Longpré Marc-Antoine , Tramontano Samantha , Cortese Franco , Rodríguez Fátima , Coldwell Beverley , Martín-Lorenzo Alba , Barbee Olivia , Pankhurst Matthew , Klügel Andreas
Published: March 2022

The 2021 eruption of Cumbre Vieja volcano (La Palma, Canary Islands) produced sustained Strombolian to violent Strombolian explosive activity, resulting in widespread tephra fall deposits in addition to lava flows. Frequent sampling of rapidly quenched volcanic ash provides the rare opportunity to document the compositional evolution of fragmenting magma at a high temporal resolution. Here we present preliminary textural observations and electron microprobe measurements of matrix glass from dated ash samples spanning the first four weeks of the eruption. Ash shards show two broad types of groundmass texture: Type 1 groundmass comprises abundant glass with microlites of plagioclase, clinopyroxene, and Fe-Ti oxides ± olivine, whereas Type 2 groundmass is microcrystalline (plagioclase, clinopyroxene, Fe-Ti oxides) and contains little to no glass. Type 1 and Type 2 groundmasses are sometimes observed mingling together at the ash shard scale. The glass composition of Type 1 groundmass is consistently tephritic, but displays significant variations over time. Glass from the earliest sample collected on 19 September is among the most primitive of the sequence, with 46.4 wt.% SiO2 and 4.0 wt.% MgO. In contrast, a sample erupted on 21–22 September records a shift to higher silica content (48.2 wt.%) and lower MgO (3.6 wt.%). Over the following five days (until 27 September), glasses return to lower silica contents, down to 45.9 wt.%, and then continue to evolve more subtly towards more primitive compositions for the next three weeks. Overall, from 21 September to 16 October, SiO2 decreases from 48.2 to 45.1 wt.%, while FeOt and MgO increase from 9.6 to 11.8 wt.% and from 3.6 to 4.1 wt.%, respectively. Chlorine concentrations also decrease from 1300 to 830 ppm. We interpret Type 1 groundmass to represent the main magma batch feeding the 2021 eruption. The observed temporal trends may be related to variable extents of microlite crystallization, particularly Fe-Ti oxides, as suggested by the association of high SiO2, low FeOt and high Fe-Ti oxide crystal fractions for the 21–27 September samples. We note that these samples coincide with a phase of the eruption characterized by highest volcanic tremor amplitudes and lowest eruption column heights (≤3 km). The origin of microcrystalline Type 2 groundmass is more ambiguous, but it may represent Type 1 magma that has undergone a more protracted cooling history, a remobilized mushy magma intersected by Type 1 magma, or lithic material. Further textural and chemical analyses of Type 1 and Type 2 groundmasses are underway to tell these scenarios apart.
Assessment of Climate Suitability for Cherry (Prunus avium L.) in Turkey in a Changing Climate
Authors: An Nazan , Turp M. Tufan , Demiralay Zekican , Kurnaz M. Levent
Published: March 2022

Cherry (Prunus avium L.) is one of the most important export crops in Turkey and Turkey has a globally significant share in cherry production with 26%. Although cherry is mostly a temperate climate fruit, different types can be grown in the regions with climate and vegetation diversities. However, it is possible to talk about irregularities and decreases in yield due to climate variability in those regions. Provinces, which are Turkey's main cherry producers, are affected by average and extreme temperature changes from climate change, and the need for alternative areas for cherry production is gradually increasing. For this reason, it is very important to see whether the cherry with high commercial value will grow in the same regions in the future due to climatic changes or new alternative areas will emerge for this fruit. Therefore, this study aims to observe climate impacts on cherry growing regions in the main producer provinces. Hereunder, in the study, climate data with 10 km resolution was obtained using a regional climate model, i.e., RegCM4.4, under the RCP8.5 pessimistic scenario for the future period of 2021-2050 with respect to the period of 1991-2018 for different phenological periods and the climate suitability index was calculated. Although regional differences are observed in the model result, it indicates that biological development of cherry in Turkey may be affected by the increase in average temperature and extreme temperature changes due to climate change.

Acknowledgement: This research has been supported by Boğaziçi University Research Fund Grant Number 17601.

 
GNSS observations of the land uplift in South Africa: Implication for water loss estimation
Authors: Mielke Christian , Karegar Makan , Gerdener Helena , Kusche Jürgen
Published: March 2022

Global Navigation Satellite System (GNSS) networks in South Africa indicate a spatially coherent uplift. The cause of this uplift is not clear, but one hypothesis is a crustal deformation due to mantle flow and dynamic topography (Hammond et al., 2021, JGR Solid Earth). We provide an alternative evidence based on elastic loading modelling and independent observations, suggesting that land water loss due to multiple drought periods is a dominant driver of land uplift in South Africa.

The use of continuously measuring GNSS stations has proven to be a successful method for quantifying terrestrial water mass changes, by inverting the observed vertical displacements of the Earth’s crust. Depending on the density of the GNSS network, this method has the potential to derive not only temporal but also spatial higher-resolution total water storage change (TWSC) than the Gravity and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) missions. Since vertical displacements in GNSS data are not only affected by water mass changes, extensive time series analyses are required to reduce or eliminate non-hydrology-related deformations, such as non-tidal oceanic and atmospheric loading. In this way, GNSS also offers an alternative method to monitor the frequently occurring droughts in South Africa, like the severe “Day Zero” drought in Cape Town from 2015-2017.

In this study, daily GNSS time series of vertical displacements (2000-present) are analysed. A long-term trend as well as annual and semi-annual signals are separated from the noisy observations using Singular Spectral Analysis (SSA). The final time series of all stations are inverted into water mass loading over a uniform grid, with the deformation properties of the Earth’s crust being defined by the Preliminary Reference Earth Model (PREM). An experimental approach shows that a 2° x 2° grid resolution of the GNSS-derived TWSC provides appropriate solutions over most of South Africa. The GNSS solution agrees with a GRACE-assimilated solution and a hydrological model at monthly scale over different provinces, with correlations up to 93% and 94%, respectively. The long-term trend averaged over the entire country is correlated with 80% and 54%, respectively. Negative long-term TWSC trends are evident in all data sets and provide compelling evidence that long-term land uplift in South Africa has a hydrological origin.
Aerobic methane production in the western Tropical North Atlantic
Authors: von Arx Jan , Kidane Abiel , Ahmerkamp Soeren , Lavik Gaute , Philippi Miriam , Schorn Sina , Kuypers Marcel , Mohr Wiebke , Milucka Jana
Published: March 2022

The surface waters of the open ocean are mostly oversaturated with methane and thus act as a net source to the atmosphere. In situ production from methylated compounds or inorganic carbon has been proposed to act as a potential source of methane in the oxygenated surface waters. However, the distribution and importance of aerobic methane production in different marine regions remains poorly constrained. We investigated the processes and microorganisms involved in aerobic methane production in the surface waters of the western Tropical North Atlantic off Barbados. Using stable isotope incubation experiments, we showed that within 24 hours methane was readily produced from methylphosphonate (MPn) but not from dissolved inorganic carbon. MPn-derived methane production reached up to ca. 8 nmol l-1 d-1, with the highest rates measured in surface waters above the deep chlorophyll maximum (DCM). Additions of inorganic phosphate resulted in the suppression of methane production in the surface waters but not below the DCM. Additional controlling factors of MPn-derived methane production, both physicochemical (depth, nutrients) as well as biological (primary production, nitrogen fixation), were also investigated. Our metagenomic and metatranscriptomic analyses revealed that various microbial groups, including Trichodesmium and Alphaproteobacteria, had the capacity to utilise MPn in situ, making them potential contributors to methane production in this region. Overall, our results highlight the importance of MPn-derived methane production in the phosphate-limited western Tropical North Atlantic and identify the controlling factors that may regulate aerobic methane production and thereby exert control over marine methane emissions.