bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Quality Studies of the Kapadak River Basin, South-Western Bangladesh with Special Emphasis on Environmental Degradation
Authors: Roy Mrinal Kanti , Roy Pulin Chandra , Reza A.H. M. Selim , Ahmed Nasir , Moniruzzaman Md. , Hossain Shahadat
Published: December 2019

The Kapadak River basin in SW Bangladesh lies on late Holocene-Recent alluvium of the Ganges deltaic plain in the north and Ganges estuarine plain in the south. The anion and cation trends in the analyzed shallow-tube well and river water are Cl-> HCO3–>NO3–>SO42- and Na+>K+>Ca2+>Mg2+ respectively. The groundwater of the area is of sodium-calcium cation facies and chloride-bicarbonate to carbonate- sulfate anion facies. The river water is of sodium-potassium cation facies and chloride-bicarbonate—sulphate to chloride –sulphate-bicarbonate anion facies. The shallow tube well is contaminated with arsenic which exceeds the WHO recommended value for drinking water (10 μg/l). The shallow water contains salinity above the standard which is unsuitable for drinking as well as for agricultural activities. The concentration of arsenic, sodium, calcium, potassium, chlorine, bicarbonate, percentage of salinity and specific electrical conductance decreases with increasing depth. The shallow tube well water of the study area is very saline exceeding the permissible limit and requires treatment. The deep tube-well water contains lower amount of arsenic and sodium, lower percentage of salinity and specific electrical conductance in comparison to shallow tube-well water. As a result, the deep tube-well water is free from arsenic toxicity and has low to high salinity hazard, but is also hard that exceeds the tolerable limit of hardness of groundwater for drinking, public health and agricultural purposes and requires softening. The Kapadak river water is highly concentrated with sodium, potassium, magnesium, calcium, chloride, bicarbonate, and specific electrical conductance which cause the deterioration of river water quality for agricultural purposes. According to the values of TDS, EC, boron concentration, Na%, and SAR, the shallow tube-well water as well as river water is of poor quality and unsafe for irrigation purposes, while the deep tube-well water is poorly safe for drinking and irrigation purposes. As a whole in the study area groundwater quality degrades from north to south as southern part is inundated regularly by saline estuarine water. The chemical weathering of rock-forming minerals influences the groundwater quality. Entrapped saline water in the aquifers during the Holocene time is the main source of salinity in this area with minor contribution from dissolution of halides and saline estuarine water in the Kapadak river due to tidal inundation.
Investigating the process of learning for school pupils on residential outdoor education courses
Authors: Scrutton Roger
Published: December 2019

Pupils’ process of learning on residential outdoor education courses is perceived by some providers, customers and researchers as a linear one in which learning takes place in the social affective domain followed by the academic affective domain and then, depending on course objectives, the cognitive domain. Other researchers envisage a non-linear process, akin to soft complexity, in which the inputs are the course characteristics and traits of the learner and the process an ‘intertwining’ and feedforward and feedback between learning domains. These theses are investigated with reference to the objectives of different course types – adventure, curriculum, combined - and it is concluded that while individual pupils learn in a complex way, outcomes at the level of the group and/or course appear to be linearly related. However, there is a question over whether a curriculum-related course can deliver the affective learning that seems to facilitate cognitive learning. This was tested experimentally with secondary school pupils attending a field studies (curriculum) course. Although the experimental group made significant cognitive gain it was not accompanied by the putative affective learning. Affective measures revealed a level of stability of pupils’ self-concept that might have inhibited affective learning. There remains potential for primary quantitative studies to test for relationships between elements of learning in different domains on residential courses and thus inform the process of learning.
Novel NF membrane triples water permeability whilst selectively removing components from raw water
Authors: Atkinson Simon
Published: December 2019

Japan's Toray Industries Inc has developed a nanofiltration (NF) membrane with a novel structure which, it says, triples water permeability, whilst selectively removing components from raw water. This article provides an insight into the technology.
A new palaeontinid (Insecta, Hemiptera, Cicadomorpha) from the Upper Jurassic Tiaojishan Formation of northeastern China and its biogeographic significance
Authors: Fu Yanzhe , Cai Chenyang , Huang Diying
Published: December 2019

Cicadomorpha guancaishanensisnew species, of the extinct family Palaeontinidae, is described from the Upper Jurassic Tiaojishan Formation at Guancaishan, Jianping County, Western Liaoning, northeastern China. It represents the first record of Palaeontinidae from the Tiaojishan Formation and highlights the palaeodiversity of the Late Jurassic palaeontinids.CicadomorphaMartynov, 1926 previously included three species with extremely limited morphological differences from the Karabastau Formation of Kazakhstan, the Glushkovo Formation, and the Ukurei Formation of Chita, Transbaikalia, and Russia, indicating a correlated stratigraphic relationship. This discovery provides new evidence that closure of the Okhotsk Ocean began in the Middle Jurassic. Thus, there is no distinct geographical barrier between the southern and northern areas of Mongolia-Okhotsk Ocean in the Late Jurassic.

UUID:http://zoobank.org/64531de4-070c-43d4-ae01-106d4338027b.
Bounds for the hazard rate and the reversed hazard rate of the convolution of dependent random lifetimes
Authors: Belzunce Félix , Martínez-Riquelme Carolina
Published: December 2019

An upper bound for the hazard rate function of a convolution of not necessarily independent random lifetimes is provided, which generalizes a recent result established for independent random lifetimes. Similar results are considered for the reversed hazard rate function. Applications to parametric and semiparametric models are also given.
Runoff on rooted trees
Authors: Jones Owen Dafydd
Published: December 2019

We introduce an idealised model for overland flow generated by rain falling on a hillslope. Our prime motivation is to show how the coalescence of runoff streams promotes the total generation of runoff. We show that, for our model, as the rate of rainfall increases in relation to the soil infiltration rate there is a distinct phase change. For low rainfall (the subcritical case) only the bottom of the hillslope contributes to the total overland runoff, while for high rainfall (the supercritical case) the whole slope contributes and the total runoff increases dramatically. We identify the critical point at which the phase change occurs, and show how it depends on the degree of coalescence. When there is no stream coalescence the critical point occurs when the rainfall rate equals the average infiltration rate, but when we allow coalescence the critical point occurs when the rainfall rate is less than the average infiltration rate, and increasing the amount of coalescence increases the total expected runoff.
The distribution and asympotic behaviour of the negative Wiener–Hopf factor for Lévy processes with rational positive jumps
Authors: Kolkovska Ekaterina T. , Martín-González Ehyter M.
Published: December 2019

We study the distribution of the negative Wiener–Hopf factor for a class of two-sided jump Lévy processes whose positive jumps have a rational Laplace transform. The positive Wiener–Hopf factor for this class of processes was studied by Lewis and Mordecki (2008). Here we obtain a formula for the Laplace transform of the negative Wiener–Hopf factor, as well as an explicit expression for its probability density in terms of sums of convolutions of known functions. Under additional regularity conditions on the Lévy measure of the studied processes, we also provide asymptotic results as

$u\to-\infty$

for the distribution function F(u) of the negative Wiener–Hopf factor. We illustrate our results in some particular examples.
Interaction of Poisson hyperplane processes and convex bodies
Authors: Schneider Rolf
Published: December 2019

Given a stationary and isotropic Poisson hyperplane process and a convex body K in

${\mathbb R}^d$

, we consider the random polytope defined by the intersection of all closed half-spaces containing K that are bounded by hyperplanes of the process not intersecting K. We investigate how well the expected mean width of this random polytope approximates the mean width of K if the intensity of the hyperplane process tends to infinity.
Completely asymmetric stable processes conditioned to avoid an interval
Authors: Lenthe Pierre , Weissmann Philip
Published: December 2019

In a recent article, Döring et al. (2018) conditioned a stable process with two-sided jumps to avoid an interval. As usual, the strategy was to find an invariant function for the process killed on entering the interval and to show that the corresponding h-transformed process is indeed the process conditioned to avoid an interval in a meaningful way. In the present article we consider the case of a completely asymmetric stable process. It turns out that the invariant function found by Döring et al. does not exist or is not invariant, but nonetheless we will characterise the conditioned process as a Markov process.
Monte Carlo integration with a growing number of control variates
Authors: Portier FranÇois , Segers Johan
Published: December 2019

It is well known that Monte Carlo integration with variance reduction by means of control variates can be implemented by the ordinary least squares estimator for the intercept in a multiple linear regression model. A central limit theorem is established for the integration error if the number of control variates tends to infinity. The integration error is scaled by the standard deviation of the error term in the regression model. If the linear span of the control variates is dense in a function space that contains the integrand, the integration error tends to zero at a rate which is faster than the square root of the number of Monte Carlo replicates. Depending on the situation, increasing the number of control variates may or may not be computationally more efficient than increasing the Monte Carlo sample size.
The encounter between Italy and Siam at the dawn of the twentieth century: Italian artists and architects in the modernising Kingdom of Siam
Authors: Lohapon Neungreudee
Published: December 2019

This paper focuses on the encounters between Italy and Siam at the dawn of the twentieth century, as it was the most dynamic period of Italian settlement in the modernising Siam. The paper analyses the development of Siamese modernisation as a challenging opportunity for Italian entrepreneurs and professionals, thanks to a healthy diplomatic relation between the two countries. Compared to the main characteristics of the Italian diaspora, the Italian colony in Siam stands out because of the fruits of its creative production. Siam was described as a symbol of tradition, not very different from the way China was often viewed, while the West was regarded as a source of modernity. With this perspective, the fact that Siam herself initiated the modernisation process, as well as the recruitment of Italians as part of the government's team in public works, architectural construction and civil engineering, was emphasised less than the part played by Italians in transforming the image of the Siamese capital. The paper examines how the encounters between Italy and Siam developed, attempting to do this from both Siamese and Italian perspectives, since both shared cultural memories, empirical evidence of cultural encounters and transculturality.
Assessment of color response and activity rhythms of the invasive black planthopper Ricania speculum (Walker, 1851) using sticky traps
Authors: Mazza Giuseppe , Marraccini Daniele , Mori Emiliano , Priori Simone , Marianelli Leonardo , Roversi Pio Federico , Gargani Elisabetta
Published: December 2019

To be effective, management strategies of invasive alien species cannot ignore their spatiotemporal behavior particularly those exerting serious damages to human activities. The black planthopper Ricania speculum is an Asian insect that has been reported as an alien invasive species in Italy, where it threatens local plant diversity, including important crops. In our work, we analyzed the activity rhythms of this species through circular statistics and the efficiency of chromotropic traps to capture adult individuals. Captures were carried out in central Italy, where the black planthopper is showing a remarkable range expansion, after its first discovery in 2009. We observed that the species was mainly crepuscular, with a high intersexual activity overlap. Activity rhythms changed between July–August and September–October, with changing heliophany, but peaked at sunset and were the lowest in the second half of the night and early morning. The insects were mostly caught by green traps, particularly in September, which is the period of egg-laying inside the leaves; conversely, orange ones were avoided, and yellow ones captured proportionally to their local availability. Strategies for controlling this species should consider concentrating trapping effort during the activity peak, using green sticky traps to enhance the capture success of each trap, with the lowest impact over non-target species.
A Study of the Application Barriers to the Use of Autonomous Ships Posed by the Good Seamanship Requirement of COLREGs
Authors: Zhou Xiang-Yu , Huang Jin-Jing , Wang Feng-Wu , Wu Zhao-Lin , Liu Zheng-Jiang
Published: December 2019

Autonomous ships are gaining in importance and are expected to shape the future of the global shipping industry. This evolutionary shift raises serious issues about compliance with the International Regulations for Preventing Collisions at Sea 1972 (COLREGs). This paper reviews the literature on autonomous ships from the perspective of the obligations of good seamanship imposed by COLREGs. The authors conclude that to facilitate the introduction of autonomous ships, the application barriers presented by COLREGs need to be analysed. With this goal, this paper presents a perspective from navigational practice. Four nautical scientists and two deck officers were invited to give their opinions. The analysis indicates that COLREGs require further elaboration and amendments to eliminate uncertainty of interpretation. In particular, the paper highlights the need to amend the ‘look-out’ rule (COLREGs Rule 5) to permit look-out by ‘computer vision’ alone while, at the same time, preserving the distinction between vessels navigating in restricted visibility and in sight of one another.
Controlling walking in Stockholm during the inter-war period
Authors: Emanuel Martin
Published: December 2019

This article offers an analysis of different approaches to control walking in Stockholm in the inter-war period. Various social actors engaged in controlling pedestrians through legislation, police monitoring, educational campaigns and traffic control technologies. But the police, municipal engineers, local politicians and road user organizations differed in their aspirations to privilege motorists over pedestrians. While the inter-war period saw a shifting balance between pedestrians and motorists in Stockholm, the transition in terms of legitimate use of city streets was incomplete. Moreover, taking pedestrians’ viewpoints into consideration, what many observers and motorists understood as rebellion against traffic rules or simply bad manners, many pedestrians found to be the safest way to cross the street.
Postconcussive Symptoms Following Mild TBI and Extracranial Injury: What Are the Contributing Factors?
Authors: Bernard Coco O. , McKinlay Audrey , Krieser David , Ponsford Jennie L.
Published: December 2019

Objectives:

Whether mild traumatic brain injury (mTBI) sustained by children results in persistent or recurrent symptoms, over and above those experienced by children who solely sustain mild extracranial injuries, remains debated. The current prospective longitudinal case-controlled study aimed to examine the relative influence of injury and noninjury factors on symptoms in preschool and primary school-aged children who sustained an mTBI or mild extracranial injury at least 8 month earlier.

Methods:

Participants were 64 parents of children (31 mTBI, 33 trauma controls) who sustained injury between ages 2 and 12, whose postconcussive symptoms across the first 3-month postinjury have been previously described. The current study assessed postconcussive symptoms at 8 or more months postinjury (M = 24.3, SD = 8.4) and examined a range of injury and noninjury predictive factors.

Results:

At or beyond 8-month postinjury, symptom numbers in the mTBI group were comparable with those of the group who sustained mild extracranial injury. Educational attainment of parents (below or above high-school attainment level) was the only predictor of symptoms at follow-up, with preexisting learning difficulties approaching significance as a predictor.

Conclusions:

While our earlier study found that mTBI was associated with symptoms at 3-month postinjury, follow-up at more than 8 months showed mTBI no longer predicted symptom reporting. While mTBI contributes significantly to the presence of symptoms in the first few months postinjury, researchers and healthcare practitioners in this field need to consider the potential impact of noninjury factors on persistent or recurrent symptoms after mTBI.
Executive Cognitive Functions and Behavioral Control Differentially Predict HbA1c in Type 1 Diabetes across Emerging Adulthood
Authors: Suchy Yana , Butner Jonathan , Wiebe Deborah J. , Campbell MaryJane , Turner Sara L. , Berg Cynthia A.
Published: December 2019

Objectives:

To examine the contributions of two aspects of executive functioning (executive cognitive functions and behavioral control) to changes in diabetes management across emerging adulthood.

Methods:

Two hundred and forty-seven high school seniors with type 1 diabetes were assessed at baseline and followed up for 3 years. The baseline assessment battery included performance-based measures of executive cognitive functions, behavioral control, IQ estimate (IQ-est), and psychomotor speed; self-report of adherence to diabetes regimen; and glycated hemoglobin (HbA1c) assay kits as a reflection of glycemic control.

Results:

Linear and quadratic growth curve models were used to simultaneously examine baseline performance on four cognitive variables (executive cognitive functions, behavioral control, IQ, and psychomotor speed) as predictors of indices of diabetes management (HbA1c and adherence) across four time points. Additionally, general linear regressions examined relative contributions of each cognitive variable at individual time points. The results showed that higher behavioral control at baseline was related to lower (better) HbA1c levels across all four time points. In contrast, executive cognitive functions at baseline were related to HbA1c trajectories, accounting for increasingly more HbA1c variance over time with increasing transition to independence. IQ-est was not related to HbA1c levels or changes over time, but accounted instead for HbA1c variance at baseline (while teens were still living at home), above and beyond all other variables. Cognition was unrelated to adherence.

Conclusions:

Different aspects of cognition play a different role in diabetes management at different time points during emerging adulthood years.
PROFESSIONAL ETHICS AND A CALL FOR PHILOSOPHICAL LITERACY
Authors: Knight Andrew
Published: December 2019

It could be argued that there is now a crisis of confidence in the professions. Although many professionals individually undertake their roles with care and diligence, there have been so many systematic failures involving professionals across a range of sectors, both in the UK and globally, that the special status enjoyed by the professions is being widely questioned. In this article, I argue that recent cases are symptomatic of a lack of ethical reasoning in professional practice, yet professions enjoy an elevated status based on claims that ethics, typically communicated in codes of conduct, are central to their purpose. I argue that to help solve this crisis, philosophical literacy needs to be promoted in school, initial professional education and continuing professional development. Passing tests to superficially demonstrate an understanding of a code is quite different from reasoning through practical dilemmas in the professional workplace with judgements informed by philosophical ideas.
DAY SHIFT GOD, NIGHT SHIFT GOD
Authors: Champagne Marc
Published: December 2019

It is usually thought that only one being can be all-knowing, all-powerful, and all-loving. Challenging this monotheist conviction, I propose a universe ruled by two deities: ‘day shift God’ oversees the events that occur while the sun is up, whereas ‘night shift God’ oversees the events that occur while the sun is down. I survey objections to this proposal and conclude that the real obstacle is not an argument, but an aesthetic preference.
A MORE DEVASTATING VERSION OF THE RAVEN PARADOX
Authors: Sayan Erdinç
Published: December 2019

Hempel's famous Raven Paradox derives from Nicod's criteria for confirmation and the Equivalence Condition, the unintuitive conclusion that things like white roses, green T-shirts and ice cubes confirm the raven hypothesis ‘All ravens are black.’ By a small rearrangement of the Equivalence Condition, I show that we can also derive the conclusion, which sounds even more intuitively intolerable, that observation of black ravens fails to confirm the raven hypothesis. We are left with the contradictory result that black ravens both confirm and do not confirm the raven hypothesis.
Fieber nach offener Sprunggelenksluxationsfraktur – eine unerwartete Diagnose
Authors: Lempert Maximilian , Pape Hans-Christoph , Jukema Gerrolt Nico
Published: December 2019

Zusammenfassung. Wir präsentieren den Fall eines Patienten mit zweitgradig offener Luxationsfraktur des oberen Sprunggelenkes und komplexer Wundsituation sowie Fieber im postoperativen Verlauf. Der ursprünglich aus Nigeria stammende Mann verbrachte seinen jährlichen Heimaturlaub in einer ländlichen Region Nigerias, als er sich im Rahmen eines Autounfalls eine rechtsseitige offene Luxationsfraktur des Sprunggelenkes zuzog. Nach initialer rudimentärer Versorgung in Nigeria erfolgte die selbstständige Rückreise in die Schweiz, wo der Patient seit mehr als zehn Jahren lebt. Hier stellte er sich bei unserem Institut für Notfallmedizin vor, und es erfolgte die stationäre Aufnahme zur operativen Versorgung. Nach Entlassung trat bei dem Patienten Fieber bis 39 °C auf, weswegen er sich erneut auf unserer Notfallstation vorstellte. Hier wurde initial von einer Wundinfektion ausgegangen und es erfolgte die Eskalation der bereits laufenden Antibiotikatherapie. Erst am zweiten stationären Tag wurde schliesslich bei weitestgehend reizlosen Wundverhältnissen, aber persistierendem Fieber, die Testung auf Malaria gemacht, die positiv ausfiel. Es erfolgte schliesslich die Verlegung auf die Klinik für Infektionskrankheiten, wo die Malaria komplikationslos ausgeheilt werden konnte.
CME: Postexpositionsprophylaxe nach Kontakt mit potenziell kontagiösen Körperflüssigkeiten aus notfallmedizinischer Perspektive
Authors: Strobel Joana , Eis Doris
Published: December 2019

Zusammenfassung. Berufliche Expositionen gegenüber potenziell kontagiösen Körperflüssigkeiten, beispielsweise durch Nadelstichverletzungen oder «Blutspritzer ins Auge», führen häufig zu einer notfallmässigen ärztlichen Konsultation. Nicht selten besteht Unsicherheit, welche diagnostischen Massnahmen unmittelbar einzuleiten sind, und in welchen Fällen eine medikamentöse Postexpositionsprophylaxe möglich und indiziert ist. Wichtig sind eine leitliniengerechte diagnostische Strategie und Risikoevaluation. Dies gilt nicht zuletzt hinsichtlich der Frage nach einer etwaigen Kostenübernahme durch die Unfallversicherung für den Fall einer Infektion. Darüber hinaus führen auch ausserberufliche Expositionen, meist nach sexuellen Risikosituationen, zu notfallmässigen Konsultationen. Ziel dieses Artikels ist es, eine Übersicht zur Vorgehensweise nach Exposition mit potenziell kontagiösem Material, bei der grundsätzlich eine Übertragung von Hepatitis-B-, Hepatitis-C- oder HI-Viren möglich ist, darzustellen sowie Empfehlungen für häufige Problemkonstellationen zu geben. Spezialfälle, die Expertenwissen bedürfen, können in diesem Rahmen jedoch nicht abschliessend betrachtet werden.
Chronisches Beckenschmerzsyndrom (CPPS) und Reizdarmsyndrom bei beruflicher Überlastung
Authors: Zeller-Simmerl Daniela
Published: December 2019

Zusammenfassung. Das chronische Beckenbodenschmerzsyndrom (CPPS) und das Reizdarmsyndrom sind Ausschlussdiagnosen und werden unter den somatoformen Störungen im ICD-10 subsumiert. Das CPPS umfasst eine Vielzahl von Synonymen und wird interdisziplinär behandelt. Die Ursachen sind vielfältig und unterstehen den bio-psycho-sozialen Aspekten. Häufig hat das chronische Schmerzsyndrom seinen Ursprung in einer somatischen Ursache und besteht trotz Abheilen der Läsion weiter, möglicherweise bedingt durch psychische Komorbiditäten und soziale Stressfaktoren. Das Reizdarmsyndrom hat sich in den letzten Jahren von der rein psychiatrischen Erkrankung zur somatischen Erkrankung gewandelt. Dies wegen den neuesten Erkenntnissen der Neurogastroenterologie, dem Wissen über das Mikrobiom, den Nahrungsmittelunverträglichkeiten und der Gut-Brain-Achse. Bei chronischen Schmerzsyndromen ist die Schmerzerhaltung und -verstärkung durch psychosoziale Aspekte beeinflusst. Deshalb sind eine ganzheitliche Betrachtung und interdisziplinäre Therapie sinnvoll.
How Green Transition of Energy System Impacts China's Mercury Emissions
Authors: Li Jiashuo , Wei Wendong , Zhen Wei , Guo Yi , Chen Bin
Published: December 2019

China has long been committing to green transition of energy system to alleviate the heavy pollution; however, a quantitative analysis for its impact on air pollution has been lacking. To fill the knowledge gap, this study makes an initial attempt to reveal how green transition of energy system influences China's energy‐related mercury emissions from both individual sector and supply chain perspectives, by using input‐output (IO)‐structural decomposition analysis and structural path analysis. Moreover, the aggregated power sector in the original IO tables are further disaggregated into seven types of power sectors to avoid the inherent huge uncertainty related to the aggregation. The results show that green transition in terms of emission factor control and energy mix adjustment has substantially benefited mercury reduction, while energy efficiency improvement has a much weaker effect. The largest consumption‐based mercury reduction brought about by energy green transition happens in sector Construction, with an amount of 49.6 t. This study also finds that the green transition generally makes the production layers less mercury intensive, and the energy‐related mercury emissions are more concentrated in the production layers. Policy suggestions for further enhancing energy green transition's mitigation effects for mercury emissions are comprehensively discussed.
Direct Air Capture Offers Some Promise in Reducing Emissions
Authors: Showstack Randy
Published: December 2019

The method offers potential in helping reduce carbon dioxide in the atmosphere but faces technological and economic hurdles.
A Stochastic Approach to Modeling Tidal Creek Evolution: Exploring Environmental Influences on CreekTopologies Through Ensemble Predictions
Authors: Li Xiaorong , Leonardi Nicoletta , Plater Andrew J.
Published: December 2019

A numerical tool integrating hydrodynamics, vegetation growth, stochastic selection, and Monte‐Carlo simulation is developed to predict channel network evolution in a newly inundated back‐barrier wetland. Focusing on the formation and evolution of tidal channels, model simulations suggest a clear tendency towards specific creek topologies with high probability despite creek evolution being subject to random perturbations. These creek topologies are primarily determined by wetland topography while the influence of vegetation is secondary. Ensemble results of Monte‐Carlo simulations identify threshold points leading to bimodal separation of the emergent creek networks characterized by different complexity and efficiency. This, in turn, assists the recognition of necessary human interventions to encourage the formation of complex and far‐reaching creek networks that can promote exchange of materials between estuaries and salt marshes and, hence, maintain salt marsh ecosystem structure and function.
Eruption Interval Monitoring at Strokkur Geyser, Iceland
Authors: Eibl Eva P. S. , Hainzl Sebastian , Vesely Nele I. K. , Walter Thomas R. , Jousset Philippe , Hersir Gylfi Páll , Dahm Torsten
Published: December 2019

Geysers are hot springs whose frequency of water eruptions remain poorly understood. We set up a local broadband seismic network for 1 year at Strokkur geyser, Iceland, and developed an unprecedented catalog of 73,466 eruptions. We detected 50,135 single eruptions but find that the geyser is also characterized by sets of up to six eruptions in quick succession. The number of single to sextuple eruptions exponentially decreased, while the mean waiting time after an eruption linearly increased (3.7 to 16.4 min). While secondary eruptions within double to sextuple eruptions have a smaller mean seismic amplitude, the amplitude of the first eruption is comparable for all eruption types. We statistically model the eruption frequency assuming discharges proportional to the eruption multiplicity and a constant probability for subsequent events within a multituple eruption. The waiting time after an eruption is predictable but not the type or amplitude of the next one.
STEVE and the Picket Fence: Evidence of Feedback‐Unstable Magnetosphere‐Ionosphere Interaction
Authors: Mishin Evgeny , Streltsov Anatoly
Published: December 2019

This paper aims to extend the understanding of Strong Thermal Emission Velocity Enhancement (STEVE) and the Picket Fence related to strong subauroral ion drifts (SAID). We numerically demonstrated that precipitating energetic electrons are critical for the structuring of the Picket Fence. It is created by feedback‐unstable magnetosphere‐ionosphere interactions driven by the SAID electric field when the Hall conductance created by energetic (
1 keV) electrons exceeds the Pedersen conductance. We show that thermal excitation of the red‐line emission in STEVE is inhibited by inelastic collisions with molecular nitrogen. Suprathermal (
500 eV) electrons coming from the turbulent plasmasphere appear to be the major source. We also show that the chemiluminescencent and radiative attachment reactions do not explain the short‐wavelength part of the STEVE continuum and argue that accounting for vibrational excitation may resolve the problem. Atmosphere's upwelling due to enhanced ion‐neutral drag leads to the increased abundance of molecular components relative to atomic oxygen.
Direct Paleomagnetic Constraint on the Closure of Paleo‐Tethys and Its Implications for Linking the Tibetan and Southeast Asian Blocks
Authors: Yan Yonggang , Zhao Qian , Zhang Yipeng , Huang Baochun , Zheng Wenjun , Zhang Peizhen
Published: December 2019

Paleomagnetic studies on the syncollisional magmatic eruptions provide a direct way to understand when and where the Paleo‐Tethys closed. We report a well‐dated paleomagnetic pole from the southern Lancangjiang volcanic belt in western Yunnan of China. Stable Characteristic Remanent Magnetizations (ChRMs) were isolated from 21 sites at high temperatures following step‐wise thermal demagnetization. The data pass fold, reversal, and conglomerate tests and are interpreted to be primary thermal remanent magnetizations. The new paleomagnetic pole (46.1°N/176.2°E, K=44.9, A95=4.8°, N=21) yields a paleolatitude of 26.0 ± 4.8°N at the reference site (23.0°N/100.4°E) in the southern Lancangjiang area. This direct paleo‐latitudinal constraint on the Paleo‐Tethys suture zone in western Yunnan indicates that the north branch of the Paleo‐Tethys Ocean closed no later than the Carnian Age of Late Triassic, and confirms a geographic linkage between the North Qiangtang and Indochina Blocks at least during the Early Permian to Late Triassic.
Quasi‐Biweekly Oscillation of the South Asian High and Its Role in Connecting the Indian and East Asian Summer Rainfalls
Authors: Wei Wei , Zhang Renhe , Yang Song , Li Wenhong , Wen Min
Published: December 2019

Investigation into the intraseasonal variation of the South Asian high (SAH) and its relationship with the Indian and East Asian summer monsoon rainfalls indicates that the 10–20 day period dominates the subseasonal zonal oscillation of the SAH between the Iranian mode and the Tibetan mode. The eastward shift of SAH lags a rainfall decrease over northern India by about 1 day, but leads a rainfall increase over the Yangtze River valley (YRV) by about 3 days. Interactive processes are also revealed on quasi‐biweekly time scales. The latent heating over northern India contributes to the southwestward shift of a pair of cyclone‐anticyclone anomalies from the midlatitudes to the SAH region, resulting in the zonal shift of the SAH. An associated upper‐level divergence over eastern China leads to the rainfall increase over the YRV 3 days later. The lead‐lag relationships revealed may benefit the subseasonal rainfall prediction over the two monsoon regions.
Modeling the Temporal Variability in Saturn's Magnetotail Current Sheet From the Cassini F‐ring Orbits
Authors: Agiwal O. , Hunt G. J. , Dougherty M. K. , Cowley S. W. H. , Provan G.
Published: December 2019

The Cassini spacecraft completed 20 highly repeatable orbits during northern summer at Saturn, known as the F‐ring orbits, of which 18 are considered in this study. The spacecraft traversed Saturn's magnetotail current sheet during each apoapsis pass between 16 and 22 Saturn radii over 2‐day intervals and revealed a highly variable radial magnetic field from orbit to orbit. The solar wind and planetary period oscillations (PPOs) are significant sources of temporal variability in the Saturnian magnetosphere. PPOs refer to dual magnetic perturbation systems, one in each hemisphere, which have been observed to modulate the position and thickness of the magnetotail current sheet with a
10.7‐hr periodicity. Thus, we employ a model which considers dual‐modulation effects of the northern and southern PPO systems, together with a model of variable solar wind forcing on the magnetotail current sheet, to investigate their combined temporal effects on the radial magnetic field in the magnetotail. For all 18 F‐ring orbits considered, the modeled radial fields show excellent overall agreement with the temporal variability in the large‐scale structure of the observed radial fields (root mean square error
1.5 nT for 80% of the orbits). The amplitudes of the northern PPO modulations are well constrained between 0.3 and 0.5 Saturn radii, and they exceed the southern modulations by a factor of 1.3. The solar wind forcing is observed to be highly variable from orbit to orbit.
Scale Transition From Geostrophic Motions to Internal Waves in the Northern South China Sea
Authors: Cao Haijin , Jing Zhiyou , Fox‐Kemper Baylor , Yan Tong , Qi Yiquan
Published: December 2019

The eddy‐abundant circulation in the northern South China Sea (NSCS) tends to be dynamically complex due to monsoon forcing, Kuroshio intrusion, and emitted internal waves from the Luzon Strait. This study uses 13‐year shipboard acoustic Doppler current profiler measurements (2004–2016), orbital altimeter data, and high‐resolution model output to perform wave‐vortex decompositions and investigate the scale of transition from dominantly geostrophic flows to internal wave motions in the northern South China Sea. The upper ocean kinetic energy spectra transition on scales exceeds 200 km. This large scale of transition is attributed to the energetic low‐mode internal waves (e.g., internal tides and inertia‐gravity waves). However, inconsistencies in the decomposition reveal that the assumptions of homogeneity and isotropy required for the 1‐D decomposition (Bühler et al., 2014) are sufficiently violated at smaller scales to affect the subdominant member of the decomposition on scales below 100 km. A method for direct quantification of the consequences by degree of violation using bootstrapping of the 2‐D model data is developed and illustrated. Observed and modeled sea surface height spectra flatten at scales smaller than 125 km, which is found in the model to be due to the coherent, semidiurnal internal waves. The large scale of transition between geostrophic and wave motions in the South China Sea is an irreducible uncertainty for altimeter velocities (e.g., the Surface Water and Ocean Topography mission).
Deducing Crustal‐Scale Reverse‐Fault Geometry and Slip Distribution From Folded River Terraces, Qilian Shan, China
Authors: Wang Yiran , Oskin Michael E. , Zhang Huiping , Li Youli , Hu Xiu , Lei Jinghao
Published: December 2019

The deep structure of active reverse faults is generally difficult to constrain from surface observations and may conceal shortening within the hinterland. Here we investigate the geometry of active, crustal‐scale reverse faulting from deformation of an unusually extensive set of river terraces preserved along the Beida River through the northwestern Qilian Shan. Two generations of fill terraces (T1 and T2) are well preserved from the foreland basin to at least 45 km within the hinterland. Optically stimulated luminescence and 10Be dating methods indicate that T1 was abandoned at 24 ± 3 kyr B.P.; T2 was abandoned at 144 ± 30 kyr B.P. The T2 terrace profile reveals a long wavelength fold (~30 km) with a largest vertical deformation of ~120 m relative to T1. Both kinematic and elastic modeling of the deformed terraces indicate that folding is a result of movement along a steep reverse fault (~50o), which merges into a ~10° décollement at 15–17 km depth. Estimated slip at depth is 1.8 times higher than fault slip at the surface, indicating a substantial proportion of shortening is absorbed by folding of the range interior. The shortening rate since abandonment of T2 is 1.4 ± 0.4 mm/yr, which is consistent with previous research and makes up 23 ± 10% of the geodetic shortening rate across Qilian Shan orogen. Our results support that crustal‐scale reverse‐faulting accommodates shortening and northward propagation of the North Qilian mountain front and that the total shortening rate is distributed between multiple faults within the Qilian Shan and Hexi Corridor.
Fish Structure in Channel Networks of a Large Anabranching Floodplain: Effect of Isolation/Connection Processes
Authors: Abrial E. , Espínola L. A. , Amsler M. L. , Rabuffetti A. P. , Latosinski F. G. , Szupiany R. N. , Eurich M. F. , Blettler M. C. M.
Published: December 2019

Channel networks of floodplain rivers are the main routes for water, sediment, organic matter, and aquatic organisms between main channels and lakes, playing a substantial role in floodplain dynamics. Despite their importance most investigations in large floodplain rivers focus on main channels and lentic water bodies. This research deals with fish assemblage variations in different lotic sites (scour holes and straight reaches) of one of the many channels which shape the wide anabranching floodplain of the middle reach of the Paraná River. We considered the influence of environmental factors, such as hydro‐geomorphological features and water quality of the channel, connections with surrounding lentic water bodies, seasonality, and interannual flow variations. The results showed two main ecological patterns closely related to floodplain connectivity. In‐channel habitat heterogeneity has low influence on fish assemblages when minor channels are connected to significant flooded areas (sampling period 2013–2016). Spatial or temporal predictions of fish structure during these stages are not easy due to the interaction of several environmental factors. However, during very low water levels (winter of 2018) most lentic areas become isolated from the nearby channel network, and floodplain fish are forced to move into the numerous scour holes of the floodplain channels where water conditions resemble those in lentic habitats. Our work highlights the importance of in‐channel characteristics of floodplain river networks and their crucial role for fish conservation, particularly during very low water stages.
A Novel Method of Quantifying Catchment‐Wide Average Peak Propagation Speed in Hillslopes: Fast Hillslope Responses are Detected During Annual Floods in a Steep Humid Catchment
Authors: Asano Yuko , Uchida Taro , Tomomura Mitsuhide
Published: December 2019

The lag time between rainfall input and discharge output—that is, the response speed of a catchment—is a key parameter for flood prediction but is difficult to quantify. Here we propose a new method to quantify catchment‐wide average peak propagation speed in hillslopes based on measurements conducted in a steep 4.5‐km2 catchment. The peak lag time of the catchment was partitioned into lag times in the hillslope and channel. Peak propagation speed was calculated from flow path length divided by lag time. We verified the results and evaluated the applicability and uncertainty of this method. This method can be applied during intense storms with identifiable peak relationships between rainfall and discharge. The effect of spatial variation in precipitation was insignificant in the study catchment. The increase in rainfall intensity and the rainfall accumulated prior to peak rainfall increased peak propagation speed. The method used to characterize flow path length from distributed values introduced some uncertainty. We calculated modal lengths using linear and logarithmic scales and various bin widths. These calculations resulted in small differences in modal channel length but led to more than tenfold differences in modal hillslope length. Thus, uncertainties for peak propagation speed across all hillslopes varied by one order of magnitude. Hillslope lag times were less than 2 min and peak propagation speed in the hillslopes ranged from 0.04 to 4.3 m/s for floods with recurrence intervals of one to several years. The proposed method and calculated data should improve prediction accuracy for extreme floods.
Rainfall‐Runoff Modeling Using Crowdsourced Water Level Data
Authors: Weeser B. , Jacobs S. , Kraft P. , Rufino M. C. , Breuer L.
Published: December 2019

Complex and costly discharge measurements are usually required to calibrate hydrological models. In contrast, water level measurements are straightforward, and practitioners can collect them using a crowdsourcing approach. Here we report how crowdsourced water levels were used to calibrate a lumped hydrological model. Using six different calibration schemes based on discharge or crowdsourced water levels, we assessed the value of crowdsourced data for hydrological modeling. As a benchmark, we used estimated discharge from automatically measured water levels and identified 2,500 parameter sets that resulted in the highest Nash‐Sutcliffe‐Efficiencies in a Monte Carlo‐based uncertainty framework (Q‐NSE). Spearman‐Rank‐Coefficients between crowdsourced water levels and modeled discharge (CS‐SR) or observed discharge and modeled discharge (Q‐SR) were used as an alternative way to calibrate the model. Additionally, we applied a filtering scheme (F), where we removed parameter sets, which resulted in a runoff that did not agree with the water balance derived from measured precipitation and publicly available remotely sensed evapotranspiration data. For the Q‐NSE scheme, we achieved a mean NSE of 0.88, while NSEs of 0.43 and 0.36 were found for Q‐SR and CS‐SR, respectively. Within the filter schemes, NSEs approached the values achieved with the discharge calibrated model (Q‐SRF 0.7, CS‐SRF 0.69). Similar results were found for the validation period with slightly better efficiencies. With this study we demonstrate how crowdsourced water levels can be effectively used to calibrate a rainfall‐runoff model, making this modeling approach a potential tool for ungauged catchments.
Precipitation‐Runoff and Storage Dynamics in Watersheds Underlain by Till and Permeable Bedrock in Alberta's Rocky Mountains
Authors: Spencer S. A. , Silins U. , Anderson A. E.
Published: December 2019

The complex mechanisms driving runoff dynamics in mountainous watersheds with thick glacial till and fractured bedrock are not well understood. We examined long‐ and short‐term precipitation‐runoff relationships and quantified subsurface storage in watersheds on the eastern slopes of Canada's Rocky Mountains to develop a conceptual understanding of runoff generation processes in this region. Fractured permeable bedrock (bedrock storage) and glacial till deposits (soil and till storage) collectively result in large dynamic storage (hydrologically active storage). The transition from multiyear dry to multiyear wet patterns increased specific discharge due to less bedrock storage opportunity but did not influence event‐scale rainfall‐runoff responses. Rather, event‐scale rainfall‐runoff responses were governed by snowmelt and soil and till storage capacity. While winter snowfall was an important predictor of annual runoff ratios, storage at the end of the previous fall also influenced runoff ratios. These complex subsurface dynamics and large storage capacities are important for understanding how mountainous watersheds with glacial till deposits may respond to disturbance or climate change.
Assimilating GRACE Into a Land Surface Model in the Presence of an Irrigation‐Induced Groundwater Trend
Authors: Nie Wanshu , Zaitchik Benjamin F. , Rodell Matthew , Kumar Sujay V. , Arsenault Kristi R. , Li Bailing , Getirana Augusto
Published: December 2019

Assimilating terrestrial water storage observations from the Gravity Recovery and Climate Experiment (GRACE) mission into land surface models (LSMs) provides an opportunity to disaggregate and downscale GRACE information to finer scales and improve water component estimates in LSMs. However, the performance of GRACE data assimilation (GRACE‐DA) is limited by the lack of representation of human activities in most LSMs. To simultaneously improve GRACE‐DA and reduce the uncertainties in the modeled anthropogenic processes, we assimilate mascon‐based GRACE terrestrial water storage into the Noah‐Multiparameterization LSM that includes groundwater extraction for irrigation. Simulations with and without GRACE‐DA and with and without groundwater pumping for irrigation are performed to study the isolated and combined effects of groundwater irrigation and GRACE‐DA on water and energy fluxes over the High Plains Aquifer (HPA). The results reveal that the DA‐only simulation may erroneously distribute increments across water storage components and affect the related fluxes through biased feedbacks, while the irrigation‐only simulation may overestimate groundwater decline due to shortcomings in the irrigation and groundwater parameterizations. Assimilating GRACE when irrigation is simulated produces the best overall performance for water storage trends over the northern HPA. For the southern HPA, GRACE assimilation with irrigation performs similarly to irrigation‐only simulation for water storage components and evapotranspiration. GRACE assimilation also improves results in nonirrigated regions and can potentially alleviate the overestimation of groundwater trends in regions with greater irrigation uncertainties. This study highlights the potential to advance hydrological data assimilation in the context of anthropogenic water consumption and land‐atmosphere interactions.