bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of urban areas on surface water loss across USA watersheds
Authors: Palazzoli Irene , Montanari Alberto , Ceola Serena
Published: March 2021

Human activities are one of the factors responsible for the rapid depletion of surface water resources. The projected growth of urban population, along with the associated process of urban sprawl, is expected to further increase anthropogenic surface water withdrawals. Although this scenario is threatening water security globally, highlighting the need for efficient and sustainable strategies of water and urbanization management, a spatially explicit analysis of the interaction between urban areas and surface water loss is still missing. In this analysis we use maps of urban areas and locations of surface water loss derived from remote sensing data across the watersheds in the United States to understand the spatial influence of human settlements on surface water depletion. By examining the distribution of the frequency of surface water loss locations as a function of distance from urban areas we find that in most of the basins as well as in the whole study area the depletion of surface water resources is higher close to human settlements. Therefore, we define a probabilistic distance-decay model to reproduce the observed decrease in surface water loss frequency and we observe that in 96% of the study area our model is effectively able to predict the observed decrease in surface water loss locations with distance from urban areas at the basin level (Pearson’s correlation coefficient r = 0.5). The same result is found for the whole study area as well (r = 0.997). Finally, we test the reliability of the distance-decay model through the comparison between the observed distance from urban areas at which on average surface water loss occurs and the theoretical value derived from the model evaluated for each basin and for the whole study area. The strong correlation (coefficient of determination R2 = 0.88) between the observed and theoretical distances proves that our probabilistic model applied across the U.S. represents a robust tool that can support the identification and the prediction of surface water depletion and can be possibly applied to other study areas.
Analysis on the heterogeneity of reservoir Chang 6 in D district of Ordos Basin
Authors: Yang Guilin , Ren Zhanli
Published: March 2021

This study is designed to evaluate the heterogeneity of the Chang 6 reservoirs in Study area, and to analyze the effect of heterogeneity on the distribution of oil. Mainly based on the sedimentary microfacies of the chang 6 reservoir, to calculate the mudstone by using the gamma curve in the logging curve, the separation layer and the interlayer were separated by 2 meters, then analyse the data of intercalation and interlayer by means of sedimentary facies, core and thin etc. We believe that the distribution of the sand in the plane and the heterogeneity of the reservoir is the main control factor of the oil distribution in the area, and it has a good area of oil, which own better properties, and the grain size more coarse; The main control factors of the Chang 6 reservoir in D area is the distribution and physical property of the sand body plane, the better the continuity and physical property of the sand body plane, and the better display of the oil-bearing property of the reservoir; The migration will occur in the vertical direction When the oil and gas meet the thinner interlayer, which will have a great influence on the distribution of oil and gas in the vertical direction; The full extent of oil and gas in the reservoir is controlled by the microscopic heterogeneity of the reservoir. In the study area, the reservoir heterogeneity influence the oil and gas distribution by the physical and lithologic characteristics, the distribution of sand body surface and the distribution of layer interval etc mainly. The study on the relationship between the heterogeneity and reservoir distribution of the Chang 6 reservoirs in the research area can be reasonably evaluated for the favorable areas of oil and gas reservoirs and prediction research areas, so as to guide the development of rational development plans in the next step.
Understanding microplastics, and visual art as a method of communication: scientific poster versus painting
Authors: Peters Sophie
Published: March 2021

This multidisciplinary dissertation investigates in detail, visual art as a method of communication, in particular about a scientific topic: microplastics and human health. Primary and secondary research conducted suggest that microplastics have potential to cause health problems in humans due to the leaching of toxic chemicals and that over 8% of an educated western sample had never heard of microplastics before. Over 30% of participants reported that a painting was a more effective form of communication about microplastics and human health than a scientific poster on the same topic, opening areas for further study into the value and process of communication through visual art.
Direct measurements of cold and hot plasma composition and EMIC waves in the outer magnetosphere: Implications for inner magnetosphere wave-particle interactions
Authors: Lee Justin , Turner Drew , Vines Sarah , Allen Robert , Toledo-Redondo Sergio
Published: March 2021

Although thorough characterization of magnetospheric ion composition is rare for EMIC wave studies, convective processes that occur more frequently in Earth’s outer magnetosphere have allowed the Magnetospheric Multiscale (MMS) satellites to make direct measurements of the cold and hot plasma composition during EMIC wave activity. We will present an observation and linear wave modeling case study conducted on EMIC waves observed during a perturbed activity period in the outer dusk-side magnetosphere. During the two intervals investigated for the case study, the MMS satellites made direct measurements of cold plasmaspheric plasma in addition to multiple hot ion components at the same time as EMIC wave emissions were observed. Applying the in-situ plasma composition data to wave modeling, we find that wave growth rate is impacted by the complex interactions between the cold as well as the hot ion components and ambient plasma conditions. In addition, we observe that linear wave properties (unstable wave numbers and band structure) can significantly evolve with changes in cold and hot ion composition. Although the modeling showed the presence of dense cold ions can broaden the range of unstable wave numbers, consistent with previous work, the hot heavy ions that were more abundant nearer storm main phase could limit the growth of EMIC waves to smaller wave numbers. In the inner magnetosphere, where higher cold ion density is expected, the ring current heavy ions could also be more intense near storm-time, possibly resulting in conditions that limit the interactions of EMIC waves with trapped radiation belt electrons to multi-MeV energies. Additional investigation when direct measurements of cold and hot plasma composition are available could improve understanding of EMIC waves and their interactions with trapped energetic particles in the inner magnetosphere.
The Effect of Pore Water Velocity on the Spectral Induced Polarization Signature of Porous Media
Authors: Schwartz Nimrod , Tsukanov Kuzma , Assa Itamar
Published: March 2021

Induced polarization (IP) is increasingly applied for hydrological, environmental and agricultural purposes. Interpretation of IP data is based on understanding the relationship between the IP signature and the porous media property of interest. Mechanistic models on the IP phenomenon relay on the Poisson-Nernst-Plank equations, where diffusion and electromigration fluxes are the driving forces of charge transport, and are directly related to IP. However, to our knowledge, the impact of advection flux on IP was not investigated experimentally, and was not considered in any IP model. In this work, we measured the spectral IP (SIP) signature of porous media under varying flow conditions, in addition to developing and solving a model for SIP signature of porous media, which takes flow into consideration. The experimental and the model results demonstrate that as bulk velocity increases, polarization and relaxation time decrease. Using a numerical model, we established that fluid flow near the particle deforms the structure of the electrical double layer (EDL), accounting for the observed decrease in polarization. Using simple physical arguments, we developed a new model for the relaxation time, taking into account the impact of bulk fluid velocity. The model and the measured and synthetic data were found to be in good agreement. Overall, our results demonstrate the sensitivity of the SIP signature to fluid flow, highlighting the need for considering fluid velocity in the interpretation of the SIP signature of porous media, and opening an exciting new direction for noninvasive measurements of fluid flow at the EDL scale.     
Drone image processing for water quality in the cloud
Authors: Knaeps Els , Moelans Robrecht , De Keukelaere Liesbeth
Published: March 2021

The use of drones to monitor water quality is relatively new. Although drones and lightweight cameras are readily available, deriving water quality parameters is not so straightforward.  It requires knowledge of the water optical properties, the atmospheric contribution and special approaches for georeferencing of the drone images.  We present a cloud-based environment, MAPEO-water, to deal with the complexity of water surfaces and retrieve quantitative information on the water turbidity, the chlorophyll content and the presence of marine litter/marine plastics. 

MAPEO-water supports already a number of camera types and allows the drone operator to upload the images in the cloud. MAPEO-water also offers a protocol to perform the drone flights and allow efficient processing of the images. Processing of the drone images includes direct georeferencing, radiometric calibration and removal of the atmospheric contribution. Final water quality parameters can be downloaded through the same cloud platform. Water turbidity and chlorophyll retrieval are based on spectral approaches utilizing information in the visible and Near Infrared wavelength ranges. Marine litter detection combines spectral approaches and Artificial Intelligence. Visible, Near Infrared and Short Wave Infrared wavelengths are used to detect marine litter but also discriminate marine litter from turbid water plumes and surface features such as glint and white caps. First tests have also been performed to apply a Convolutional Neural Network (CNN) for the automatic recognition of the marine plastic litter.
A simple measurement device for groundwater flow velocity using inkjet-printed drawing paper
Authors: Yamamoto Koichi , Ono Fumiya
Published: March 2021

We have developed a single-dot paper disk type groundwater flow current meter (single-dot PDV), which is a measuring device that easily measures the groundwater flow velocity from the traces of dots printed on paper using dye ink as a tracer. Correction coefficient based on numerical calculation for the coefficient for converting the sensor-flow velocity to the Darcy flow velocity. The correction coefficient can be expressed by a linear function of the hydraulic conductivity, and the flow velocity can be calibrated by an arbitrary hydraulic conductivity. The measurement principle of PDV was that the ink on the paper disc elutes from the paper and moves in the permeable sponge. After that, it was clarified that tailing occurred by dyeing the ink on the drawing paper. The ink movement speed and the groundwater flow velocity are proportional, and it has been shown that it is appropriate to measure the groundwater flow velocity by the tailing length.
Towards polluter group specific emission corrections with 4D-Var data assimilation
Authors: Backes Pascal , Franke Philipp , Lange Anne Caroline , Hendrik Elbern , Astrid Kiendler-Scharr
Published: March 2021

Emission data of trace gases and aerosols are crucial for atmospheric chemistry models. Since in general emissions cannot be measured directly, they are estimated using various proxy data. Available inventories  contain annual  values of trace gas and aerosol emissions within   given areas, and  further split into polluter groups such as road traffic or industry. This separation  does not take current meteorological and societal effects into account. Thus, the emission data is known to include possibly large uncertainties.

In this work, we develop a system to assess the contribution and their uncertainties of  different source categories toe air pollution. As observations of pollutants cannot be directly  linked to their source, the four-dimensional variational data assimilation system of the EURopean Air pollution Dispersion – Inverse Model (EURAD-IM) is extended towards a polluter source specific emission correction method. Therefore, the possibility of exploiting different spatial distributions, diurnal cycles, and chemical compositions of the polluter groups is investigated on the model domain of North Rhine-Westfalia, Germany, with 1km x 1km horizontal resolution, where emission by road traffic and industry are the dominant sources for most trace gases and aerosol. As a first approach, we rely on the assumption that pollutants of the same emission sector can be  assigned to the same correction factor. From the simulations, separation criteria between different pollution sources are derived as a basis of a decision algorithm applying a random forest method. We found that this system is able to separate emissions between important polluter groups like traffic, industry, and agriculture at least in the cases of high emissions, in well observed areas and during suitable meteorological situations. This means the system performes best when assimilating observations from measurement stations leeward of emission sources and thus integrating sufficient information content to characterize the polluter.
The “Ideal Spectrograph” for Atmospheric Observations
Authors: Platt Ulrich , Wagner Thomas , Kuhn Jonas , Leisner Thomas
Published: March 2021

The analysis of atmospheric trace gas distributions by absorption spectroscopy of scattered sunlight in the near UV to near IR spectral ranges has proven to be extremely useful. A central parameter for the achievable sensitivity and spatial resolution of spectroscopic instruments is the étendue (product of aperture angle and entrance area) of the spectrograph, which is at the heart of the instrument. The étendue of an instrument can be enhanced by (1) up-scaling all instrument dimensions or (2) by changing the instrument F-number, (3) by increasing the entrance area, or (4) by operating many instruments (of identical design) in parallel. While options (1) and (4) allow enhancement by (in principle) arbitrary factors, the effect of options (2) and (3) and measures like better grating efficiency is limited.

We present new ideas and considerations on how instruments for the spectroscopic determination of atmospheric gases could be optimized with respect to étendue per volume (or mass) by using new possibilities in spectrograph design and manufacturing. Particular emphasis is on arrays of massively parallel instruments for observations using scattered sunlight. Such arrays can reduce size and weight of instruments by orders of magnitude, while preserving spectral resolution and light throughput. We also discuss the optimal size of individual spectrographs in a spectrograph array and give examples of grating spectrograph systems for use on a (low Earth orbit) satellite including one with sub-km ground pixel size and daily global coverage.
Deglaciation of the central sector of the Cordilleran Ice Sheet in northern British Columbia
Authors: Dulfer Helen , Margold Martin
Published: March 2021

The Cordilleran Ice Sheet (CIS) repeatedly covered western Canada during the Pleistocene and attained a volume and area similar to that of the present-day Greenland Ice Sheet at the Last Glacial Maximum. Numerical modelling studies of the CIS during the last glacial-interglacial cycle indicate the central sector of this ice sheet, located in mountainous northern British Columbia, played an important role during both the advance and retreat phases. Additionally, the models indicate that the rapid climate oscillations at the end of the Pleistocene had a dramatic effect on the CIS. The abrupt warming at the onset of the Bølling-Allerød caused significant thinning of the ice sheet, resulting in a fifty percent reduction in mass, while the subsequent cooling caused the expansion of alpine glaciers across the former central sector of the CIS. However, the mountainous terrain and remote location have thus far impeded our understanding of this important region of the CIS, and the ice sheet configuration during the Late Glacial remains poorly constrained. 

Here we use the glacial landform record to reconstruct the deglaciation dynamics of the central sector of the CIS during the Late Pleistocene climate reversals. Numerous high elevation meltwater channels suggests the early emergence of mountain peaks above the ice sheet and the configuration of ice marginal landforms, particularly lateral meltwater channels, eskers, kame terraces and ice-contact deltas, allows the westward retreat of the ice margin to be traced towards ice dispersal centres in the Skeena and Coast mountains. Hundreds of arcuate, sharp-crested terminal moraines delineate the extent of alpine glaciers, ice caps and ice fields that regrew on mountain peaks above the CIS and numerical dating indicates that this readvance occurred during the Late Glacial period. Additionally, at some locations, cross-cutting relationships preserve the interaction of the local readvance glaciers with the trunk glaciers of the CIS, allowing the extent of the central sector of the CIS during the Late Glacial period to be reconstructed for the first time.  
A quantitative assessment of geodiversity in UNESCO Global Geoparks
Authors: Polman Emma , Kissling W. Daniel , Seijmonsbergen Harry
Published: March 2021

UNESCO Global Geoparks aim to protect globally significant geoheritage and geodiversity. However, the representativeness of geodiversity in these geoparks has never been quantified in a global context. Here, we quantify geodiversity in 147 UNESCO Global Geoparks and compare the outcome to global, Asian and European geodiversity using a geodiversity index with a global coverage, based on openly available geological, soil, hydrological and topographical input data. The global geodiversity index has five categories (from very low to very high) based on the total scores of the individual geodiversity components per 10 x 10 km grid cell.  In addition, we assessed the occurrence of soil types and lithology types in geoparks using global lithology and soil datasets. Our results show that total geodiversity, lithological diversity and topographical diversity were significantly higher in UNESCO Global Geoparks compared to random locations of parks, reflecting that many geoparks are located in mountainous areas where lithological and topographic diversity is high. Soil diversity and hydrological diversity were not significantly higher in geoparks compared to random areas, and 22% and 65% of all globally occurring soil types and lithology types were not represented in any geopark. This indicates that soil and hydrology features are not sufficiently represented in the criteria used to establish geoparks (which emphasize geological and geomorphological features), and that current geoparks are unevenly distributed across the world, with most of them being located in Asia and in Europe. Our results highlight important gaps in geodiversity conservation and can help to identify which areas of high soil and hydrological diversity are currently underrepresented and which soil and lithology types should be included in future efforts to improve the representativeness of UNESCO Global Geoparks.
The future location of auroral zones as described by the geomagnetic field of internal origin
Authors: Maffei Stefano , Livermore Philip , Mound Jonathan
Published: March 2021

The internal component of the geomagnetic field (generated within the Earth's core) is of crucial importance in modulating the impact of space weather events. Although primarily a dipolar field of slowly decreasing intensity, multipolar components can cause changes on interannual time-scales that are important for space weather applications. Of particular importance for space weather application is the location of the auroral oval, the region where it is most likely to see polar auroras. The auroral zone can be defined as a time-averaged auroral oval and it is possible to describe it via the internal geomagnetic field.

To be able to forecast interannual and decadal changes of the auroral oval location can benefit the design of future space missions and the planning of mitigation strategies for countries particularly exposed to severe space weather events (such as the UK).

Here we combine various future evolution scenarios for the geomagnetic field of internal origin with a definition of the auroral zones that rests on the calculation of non-orthogonal, magnetic coordinates. This methodology agrees well with calculations based on more complete magnetospheric and ionospheric physics. We apply our methodology to derive quantitative forecasts for the auroral zones' location over the next decades. 
Using glaciers to identify, monitor, and predict volcanic activity
Authors: Martin Michael , Barr Iestyn , Edwards Benjamin , Symeonakis Elias , Spagnolo Matteo
Published: March 2021

Many (about 250) volcanoes worldwide are occupied by glaciers. Often glaciers are regarded as problematic for volcano monitoring, since glacier ice potentially masks evidence of volcanic activity. The most devastating volcanic eruptions of the last 100 years involved volcano-glacier interactions. The 1985 eruption of Nevado del Ruiz killed 23000 people, and the 2010 eruption of Eyjafjallajökull led to the closure of many European airports. Therefore, it is imperative to minimize these impacts on society by improving methods for monitoring of glacier-clad volcanoes. Amongst several methods, optical satellite remote sensing techniques are perhaps most auspicious, since they frequently have a relatively high temporal and spatial resolution, and are mostly freely available. They often clearly show the effects of volcanic activity on glaciers, including ice cauldron formation, ice fracturing and glacier terminus changes potentially due to subglacial melt or subglacial dome growth. This study has the objective to link pre-, syn- and post-eruption glacier behaviour to the type and timing of volcanic activity, and to develop a satellite based predictive tool for monitoring future eruptions. Despite several studies that link volcanic activity and changing glacier behaviour, the potential of using the latter to predict the former has yet to be systematically tested. Our approach is to observe how glaciers responded to past volcanic events using mostly, but not exclusively optical satellite imagery, and to build a database of examples for potential automated detection and forecasting on a global scale.
A study about the linearity of trends between extreme and mean temperatures in Argentina
Authors: Suli Solange , Rusticucci Matilde , Collazo Soledad
Published: March 2021

Small variations in the mean state of the atmosphere can cause large changes in the frequency of extreme events. In order to deepen and extend previous results in time, in this work we analyzed the linear relationship between extreme and mean temperature (Τ) on a climate change scale in Argentina. Two monthly extreme indices, cold nights (TN10) and warm days (TX90), were calculated based on the quality-controlled daily minimum and maximum temperature data provided by the Argentine National Meteorological Service from 58 conventional weather stations located over Argentina in the 1977–2017 period. Subsequently, we evaluated the relationship between the linear trends of extremes and mean temperature on a seasonal basis (JFM, AMJ, JAS, and OND). Student's T-test was performed to analyze their statistical significance at 5%. Firstly, positive (negative) and significant linear regressions were found between TX90 (TN10) trends and mean temperature trends for the four studied seasons. Therefore, an increase in the Τ-trend maintains a linear relationship with significant increase (decrease) of warm days (cold nights). Moreover, we found that JFM was the one with the highest coefficient of determination (0.602 for hot extremes and 0.511 for cold extremes), implying that 60.2% (51.1%) of the TX90 (TN10) trend could be explained as a function of the Τ-trend by a linear regression. In addition, in the JFM (OND) quarter, the TX90 index increased by 7.02 (6.02) % of days each with a 1 ºC increase in the mean temperature. Likewise, the TN10 index decreased by 4.94 (and 4.99) % of days from a 1ºC increase in the mean temperature for the JFM (AMJ) quarter. Finally, it is worthwhile to highlight the uneven behavior between hot and cold extremes and the mean temperature. Specifically, it was observed that the slopes of the linear regression calculated for the TX90 index and Τ presented a higher absolute value than those registered for the TN10 index and Τ. Therefore, a change in the mean temperature affects hot extremes to a greater extent than cold ones in Argentina.
Heat transfer estimation through a high-temperature geothermal field in New Zealand quantified by multi-channel data modelling
Authors: Ardid Alberto , Archer Rosalind , Dempsey David
Published: March 2021

In high-temperature geothermal systems, understanding heat transfer helps conceptualize the whole system as well as estimating the resource size. To obtain the fullest picture, it is necessary to integrate different types of data, e.g., surface electromagnetic surveys, wellbore lithology, geochemistry, and temperature logs. This can be achieved through joint modelling. Here, we quantify the spatial distribution of heat transfer through the hydrothermally-altered, impermeable smectite layer that has developed atop the Wairākei-Tauhara geothermal system, New Zealand. Our approach involves first constraining 1D magnetotelluric (MT) inversion models with methylene blue analysis (MeB, an indicator of conductive smectite clay) and mapping these onto temperature and lithology data from geothermal wells. Then, one-dimensional models of heat transfer are fitted to well temperature logs to estimate heat flux variations across the field. We use our integrated method to estimate the average heat flux through the clay cap (2.2 W/m2) and total heat flow (380 ± 21 MW) of the Wairākei-Tauhara geothermal field. This approach models multiple datasets for estimating heat fluxes and could be applied in geothermal provinces around the world with implications for sustainable resource management and our understanding of magmatic systems.
Predicting Source Water Quality Following Wildfires Using Hydrologic Modeling
Authors: Wampler Katie , Bladon Kevin D. , Faramarzi Monireh
Published: March 2021

Forested watersheds are critical sources of the majority of the world’s drinking water. Almost one-third of the world’s largest cities and two-thirds of cities in the United States (US) rely on forested watersheds for their water supply. These forested regions are vulnerable to the increasing incidence of large and severe wildfires due to increases in regional temperatures and greater accumulation of fuels. When wildfires occur, increases in suspended sediment and organic carbon can negatively affect aquatic ecosystem health and create many costly challenges to the drinking water treatment process. These effects are often largest in the first year following a wildfire. While past research has shown the likelihood of source water impacts from wildfire, the magnitude of effects remains uncertain in most regions. In our study, we will quantify the projected short-term effects of three large (>70,000 ha) wildfires on key water quality parameters (sediment and organic carbon) in two important forested source watersheds in the Cascade Range of Oregon, US. We calibrated and validated a modified Soil and Water Assessment Tool (SWAT) to simulate streamflow, sediment loads and transport, as well as in-stream organic carbon processes for a historical period prior to wildfire. The calibrated model parameters were then modified based on literature values and burn severity maps to represent post-fire conditions of the three large wildfires. The parameter adjustments for simulating wildfire will be validated with post-fire water quality field samples from the wildfires. We will present estimations of future water quality impacts in the burned watersheds under different precipitation conditions at a daily scale for the first year following the wildfires, which will provide testable hypotheses. Additionally, we will determine catchment characteristics most critical in determining the post-fire water quality response. This work will help predict the magnitude of effects from these historic wildfires, which can inform forest and drinking water management decision making.
    Cocktails of pesticide residues in conventional and organic farming systems in Europe – legacy of the past and turning point for the future
Authors: Silva Vera , Geissen Violette , Lwanga Esperanza Huerta , Beriot Nicolas , Oostindie Klaas , Bin Zhaoqi , Pyne Erin , Busink Sjors , Zomer Paul , Mol Hans , Ritsema Coen J.
Published: March 2021

Considering that pesticides have been used in Europe for over 70 years, a system for monitoring pesticide residues in EU soils and their effects on soil health is long overdue. In an attempt to address this problem, we tested 340 EU agricultural topsoil samples for multiple pesticide residues. These samples originated from 4 representative EU case study sites (CSS), which covered 3 countries and four of the main EU crops: vegetable and orange production in Spain (S-V and S-O, respectively), grape production in Portugal (P-G), and potato production in the Netherlands (N-P). Soil samples were collected between 2015 and 2018 after harvest or before the start of the growing season, depending on the CSS. Conventional and organic farming results were compared in S-V, S-O and N-P. Soils from conventional farms presented mostly mixtures of pesticide residues, with a maximum of 16 residues/sample. Soils from organic farms had significantly fewer residues, with a maximum of 5 residues/sample. The residues with the highest frequency of detection and the highest content in soil were herbicides: glyphosate and its main metabolite AMPA (P-G, N-P, S-O), and pendimethalin (S-V). Total residue content in soil reached values of 0.8 mg kg-1 for S-V, 2 mg kg-1 for S-O and N-P, and 12 mg kg-1 for P-G. Organic soils presented 70-90% lower residue concentrations than the corresponding conventional soils. There is a severe knowledge gap concerning the effects of the accumulated and complex mixtures of pesticide residues found in soil on soil biota and soil health. Safety benchmarks should be defined and introduced into (soil) legislation as soon as possible. Soil remediation techniques should be developed to keep the levels of pesticide residues below such benchmarks. Furthermore, the process of transitioning to organic farming should take into consideration the residue mixtures and their residence time in soil.  
Local time and longitudinal differences in the occurrence frequency of ionospheric EMIC waves during magnetic storm periods
Authors: Wang Hui , He Yangfan , Luehr Hermann
Published: March 2021

The spatial and temporal distributions of ionospheric electromagnetic ion cyclotron (EMIC) waves during magnetic storms from 2014 to 2018 were studied using Swarm observations. Ionospheric EMIC waves preferably occurred during storms and their recovery phases at subauroral regions within an average magnetic latitude of 40°-55°. There were more wave events during more intense and longer period storms. However, the correlation between event number and storm duration was not good. This might be due to the effect of heavy oxygen ions on EMIC wave generation and the loss of ring current high-energy ions by the EMIC waves. There are obvious magnetic local time (MLT) differences in the peak occurrence frequency of EMIC waves during storm phases. The enhanced solar wind dynamic pressure was favorable for duskside EMIC waves. With an increased substorm activity the wave occurrence rate peak shifted from the morning side to the dusk-premidnight sector. During the recovery phase of a storm, EMIC waves in the 12-24 MLT sector appeare preferably in the earlier part than those in the 00-12 MLT sector. This shift in local time is related to the eastward rotation of the plasmaspheric plume towards morning during the late storm recovery phase and its overlap with the ring current.  Highest occurrence frequency of the storm time EMIC waves could be found in the South Atlantic Anomaly region, which might be related to the drift shell splitting

and the wave propagation effect in the weak magnetic field region

.
GNSS network of Uzbekistan: achievements, prospects and challenges
Authors: Fazilova Dilbarkhon , Magdiev Hasan , Sichugova Lola
Published: March 2021

In 2005, a governmental program for the creation of a geodetic network (SGN) based on GNSS measurements started in the Republic of Uzbekistan. Its main goal is to provide a modern, reliable and accurate geocentric coordinate system for land management, construction, environmental protection and the creation of a spatial database for various sectors of the economy. The SGN established in the country based on the availability of infrastructure and geographical needs and therefore, it does not cover the entire country. SGN consists three levels: reference geodetic points (RGP), high precision satellite geodetic network (SGN-0) points and first class satellite geodetic network (SGN-1) points. Since 2018, a network of 50 Continuously Operating Reference Stations (CORS) has also been developing. The installation of more than 200 GNSS stations in the period from 2005 to 2020 allows the country's scientific community to solve a number of practical geodetic problems. Among them implementation global ITRS system into local area for transition to new national geocentric coordinate system, quasi-geoid determination based on high degree Global Geopotential Models (such as EGM2008, EIGEN-6C4, GECO) and local geodynamic research for stress field modeling.
On the geometry of baselines suitable for UT1 estimation with VLBI Intensive sessions
Authors: Kern Lisa , Schartner Matthias , Soja Benedikt , Nothnagel Axel , Böhm Johannes
Published: March 2021

One hour single baseline VLBI sessions, so-called Intensives, are routinely observed to derive UT1-UTC with a short latency. The selection of baselines for VLBI Intensive sessions and their application for the determination of UT1-UTC is a complex task. Thus far, it has been understood that long east-west extensions are critical for the accuracy of UT1-UTC. In this presentation, we show, that the answer is not as simple as that. 

We run Monte-Carlo simulations for a global 10° grid of artificial station locations and discuss the suitability of the individual baselines for UT1-UTC estimation based on the formal error of dUT1. The antennas are located at latitudes of -80° to 80° and longitudes of 0° to 180° and are assumed to have the same properties than the WETTZ13S telescope. The nine stations at longitude 0° on the northern hemisphere are defined as reference stations. In total, 2898 possible baselines between the reference stations and other artificial stations are investigated over one year based on monthly schedules to minimize potential seasonal variations. Thus, with this study, it is possible to derive a complete picture of which baselines are most suitable for dUT1 estimates. 

In general, the findings show optimal global geometries concerning Intensives. For example, we can confirm that the IVS-INT1 baseline including the stations Kokee and Wettzell is among the best ones available. Furthermore, we show that north-south baselines are also sensitive to dUT1 as long as their orientations are not parallel to the Earth rotation axis. Moreover, we highlight that east-west baselines on the equator are not suitable for estimating dUT1 due to the lack of variety in right-ascension of the visible sources. Additionally, we highlight, that very long baselines are problematic due to the highly restricted mutual visibility.
Iceberg modelling with NEMO
Authors: M. Marson Juliana , Myers Paul G.
Published: March 2021

Icebergs represent around half of the yearly mass discharge from the Greenland Ice Sheet. They are not only important freshwater sources, but also pose a threat to navigation and other offshore activities. Since monitoring individual icebergs in large numbers is unfeasible, numerical models are great tools to evaluate their role in freshwater distribution and their general trajectory patterns. While large-scale iceberg modelling is in its infancy, we show recent model improvements done in the Nucleus for European Modelling of the Ocean (NEMO) iceberg module. Among those, we highlight a newly implemented iceberg-sea ice dynamic, where icebergs are locked in concentrated and strong sea ice packs, so they will move with sea ice instead of across it. Additionally, recent code modifications allow the user to choose if the iceberg melt plume is inserted in the ocean’s first model layer or distributed along the iceberg draft. Results will show if these code upgrades change the way freshwater is distributed in the ocean and if they better represent iceberg trajectories and their surge seasonality off the Labrador shelf.
Detection of Local Mixing in Time-Series Data Using Permutation Entropy
Authors: Bradley Elizabeth , Neuder Michael , Garland Joshua , White James , Dlugokencky Edward
Published: March 2021

  While it is tempting in experimental practice to seek as high a  data rate as possible, oversampling can become an issue if one takes measurements too densely.  These effects can take many  forms, some of which are easy to detect: e.g., when the data sequence contains multiple copies of the same measured value.  In other situations, as when there is mixing—in the measurement apparatus and/or the system itself—oversampling effects can be harder to detect.  We propose a novel, model-free technique to detect local mixing in time series using an information-theoretic technique called permutation entropy.  By varying the temporal resolution of the calculation and analyzing the patterns in the results, we can determine whether the data are mixed locally, and on what scale.  This can be used by practitioners to choose appropriate lower bounds on scales at which to measure or report data.  After validating this technique on several synthetic examples, we demonstrate its effectiveness on data from a chemistry experiment, methane records from Mauna Loa, and an Antarctic ice core.
Plasma Waves Near the Electron Cyclotron Frequency in the Near Sun Solar Wind: Wave Mode Identification and Driving Instabilities
Authors: Malaspina David , Wilson Lynn , Ergun Robert , Bale Stuart , Bonnell John , Dudok de Wit Thierry , Goetz Keith , Goodrich Katherine , Harvey Peter , MacDowall Robert , Pulupa Marc , Halekas Jasper , Case Anthony , Larson Davin , Stevens Michael , Whittlesey Phyllis
Published: March 2021

Recent studies of the solar wind sunward of 0.25 AU using the Parker Solar Probe spacecraft reveal that that solar wind can be bimodal, alternating between near quiescent regions with low turbulent fluctuation amplitudes and Parker-like magnetic field direction and regions of highly turbulent plasma and magnetic field fluctuations associated with ‘switchbacks’ of the radial magnetic field.  

The quiescent solar wind regions are highly unstable to the formation of plasma waves near the electron cyclotron frequency (fce), possibly driven by strahl electrons, which carry the solar wind heat flux, and may provide one of the most direct particle diagnostics of the solar corona at the source of the solar wind.  These waves are most intense near ~0.7 fce and ~fce. The near-fce waves are found to become more intense and more frequent closer to the Sun, and statistical evidence indicates that their occurrence rate is related to the sunward drift of the core electron population.  

In this study, we examine high time resolution burst captures of these waves, demonstrating that each wave burst contains several distinct wave types, including electron Bernstein waves and extremely narrow band waves that are highly sensitive to the magnetic field orientation. Using properties of these waves we provide evidence to support the identification of their likely plasma wave modes and the instabilities responsible for generating these waves.  By understanding the driving instabilities responsible for these waves, we infer their ability to modify electron distribution functions in the quiescent near-Sun solar wind.  
Geological fissures: linking sub-surface structures to surface processes
Authors: Holdsworth Bob , Hardman Kit , Walker Rich , Bubeck Alodie , Greenfield Cat , Lee Jack , McCaffrey Ken , Dempsey Eddie
Published: March 2021

Dilatant fissures are a common feature at the Earth’s surface in active rift systems where faults cut mechanically-strong rocks, such as igneous rocks, metamorphic basement or carbonates. Much attention has focused on modern examples of large-aperture fissures in basaltic rocks, where in most cases, only the near-surface-expression is accessible to depths of ~100 m. Numerous mechanisms have been proposed for the formation of such dilatant fractures, including near-surface tensile fracturing along active normal faults at depth, geometric mismatch along faults, and fault-block rotation. However, fissure system architecture and connectivity in the subsurface, and the depth to which dilatant sections can grow are less well understood, as are the ways in which such structures may interact with surface processes.

In this presentation, we focus on dilatant faults and fractures from the ancient rock record, including examples hosted in rocks below regional erosional unconformities, commonly on the upfaulted flanks of nearby sedimentary basins. Such fissures are typically sub-vertical Mode I fractures that can be kilometres long, tens of metres wide and can extend to depths of 1 km or more below the palaeosurface. They are filled with a remarkably diverse range of high porosity, high permeability fills which act as natural proppants holding fractures open for tens to hundreds of million years. Fills include: wall rock collapse breccias; clastic or carbonate sediment; fossiliferous materials, and a variety of epithermal mineral deposits with characteristically vuggy forms and cockade-like textures. Alteration related to weathering and/or near-surface epithermal mineralization may extend down fissure systems to depths of many hundreds of metres. The subterranean clastic fills are commonly water-lain and preserve a unique record of the stratigraphic or fossil record that may be missing due to erosion at the overlying unconformity. Fissures can form along active normal faults at depth, as later-stage reactivations of pre-existing exhumed fault zones and along regional joint sets associated with folds. Some fissures form along the margins or interior of pre-existing mafic dykes or may act as sites of subsequent dyke emplacement – or both. Sub-unconformity fissure systems and their associated fills are likely to be a major influence on both the fluid storage capacity and flow behaviour in subsurface reservoirs including those hosting hydrocarbons, geothermal resources, and in aquifers worldwide.
Pengaruh Jenis dan Kosentrasi Daging Ikan terhadap Mutu Organoleptik Bubur Ikan
Authors: Akbar Muhammad , Tangke Umar , Lekahena Vanessa N. J.
Published: March 2021

Bubur ikan adalah salah satu jenis diversifikasi dan merupakan produk olahan lokal yang selama ini sudah dikenal luas oleh masyarakat Maluku sebagai olahan pada acara adat, keagamaan sampai pada penyajiannya sebagai makanan konsumsi pada bulan ramadhan. Pembuatan bubur ikan oleh masyarakat Maluku umumnya masih bersifat turun temurun dimana mereka lebih mengandalkan pengalaman, hal ini tentunya akan sangat berdampak pada penggunaan bahan dan cita rasa produk yang dihasilkan. Penelitian ini dilaksanakan untuk mencari formulasi yang tepat untuk jenis bubur ikan terkait dengan penggunaan jenis dan konsentrasi daging ikan. Dengan menggunakan rancangan acak lengkap faktorial sebagai alat analisis dengan tujuan untuk mengetahui mutu organoleptik bubur ikan dengan menggunakan jenis dan konsentrasi yang berbeda serta mendapatkan formula yang terbaik. Hasil penelitian menunjukan bahwa sebagian besar perlakuan tidak berpengaruh nyata terhadap mutu organoleptik bubur ikan dimana pada perlakuan jenis ikan nilai mutu organoleptik tekstur berpengaruh nyata sedangkan kenampakan, bau bubur ikan tidak berpengaruh nyata, aroma, rasa dan warna, pada perlakuan konsentrasi daging ikan semua mutu organoleptik tidak berpengaruh nyata, sedangkan untuk perlakuan interaksi hanya mutu organoleptik kenampakan yang berpengaruh nyata dan pada perlakuan interaksi antara jenis ikan dan konsentrasi daging ikan perlakuan terbaik adalah pada perlakuan A1B1, A1B2, A2B1, A2B2, dan A2B3. Dimana perlakuan A1 adalah jenis ikan layang, A2 jenis ikan julung, B1 konsentrasi 25 g, B2 konsentrasi 50 g dan B3 konsentrasi 75g.
Evaluasi Sistem Pengendalian Intern Penerimaan dan Pengeluaran Kas untuk Organisasi Non Profit (Studi Empiris pada Jemaat GPM Amahusu)
Authors: NATEN SIMSON
Published: March 2021

Gereja-gereja memiliki pemahamanan prinsip dan pola pelayanan bergereja yang berbeda terutama dalam pengembangan dan penerapan pengendalian internnya. Sehingga gereja di perhadapakan pada masalah Pemanfaatan kas dalam menjalankan aktifitasnya. Kondisi ini memungkinkan kas berpotensi terhadap kesalahan pencatatan, penyimpangan maupun penyalahgunaan yang tidak sesuai dengan prosedur. Karena itu untuk menghasilkan suatu informasi akuntansi yang baik dibutuhkan pengendalian intern yang baik, harus di bentuk suatu fungsi yang baik pula untuk mengawasi penerimaan dan pengeluaran kas melalui pencatatan akuntansi. Penelitian ini bertujuan untuk mengetahui penerapan pengendalian intern yang dijalankan oleh Gereja Protestan Maluku khususnya Jemaat GPM Amahusu Klasis Pulau Ambon, apakah penerapan pengendalian intern terhadap penerimaan dan pengeluaran kas yang dilakukan sudah sesuai teori akuntansi yang ada. Metode penelitian yang digunakan dalam penelitian ini, adalah dengan wawancara, observasi dan dokumentasi. Teknik analisis data yang digunakan dalam penelitian ini adalah: (1) Mendeskripsikan pengendalian intern penerimaan dan pengeluaran kas terhadap struktur organisasi, system otorisasi, prosedur pencatatan, serta praktik yang dijalankan oleh Gereja Protestan Maluku Jemaat Amahusu. (2) Menguji dan menganalisis penerapan sistem pengendalian intern  penerimaan dan pengeluaran kas pada Jemaat GPM Amahusu apakah sudah berjalan efektif. 3. Melihat bagaimana bentuk system pengendalian intern terhadap penerimaan dan pengeluaran kas Jemaat GPM Amahusu sudah berjalan efektif. Berdasarkan hasil analisa yang telah dilakukan, dapat disimpulkan bahwa pelaksanaan pengendalian intern penerimaan dan pengeluaran kas yang dilakukan gereja-gereja di Rayon Bantul masih terdapat beberapa hal yang belum sesuai dengan Sisitem Pengendalian Interen (SPI), tetapi telah disesuaikan dengan kondisi yang ada dalam gereja. Beberapa hal yang kurang sesuai adalah dalam hal pemisahan fungsi yang dalam praktiknya belum dilakukan secara tegas, otoritas dan adanya nomor bukti yang tidak tercetak.