bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarization effects in standard model parton distributions at very high energies
Authors: Bauer Christian W. , Webber Bryan R.
Published: March 2019

Abstract

We update the earlier work of refs. [1, 2] on parton distribution functions in the full Standard Model to include gauge boson polarization, non-zero input electroweak boson PDFs and next-to-leading-order resummation of large logarithms.
A Multilevel Model Examining the Relationships Between Workplace Spirituality, Ethical Climate and Outcomes: A Social Cognitive Theory Perspective
Authors: Otaye-Ebede Lilian , Shaffakat Samah , Foster Scott
Published: March 2019

The role and influence of workplace spirituality on individual and organisational outcomes continue to draw attention among management scholars. Despite this increased attention, extant literature has yielded limited insights particularly into the impact and influence processes of workplace spirituality on performance outcomes at both the individual and unit levels of analysis. Addressing this gap in research, we proposed and tested a multilevel model, underpinned by social cognitive theory, that examines the processes linking perceptions of workplace spirituality and performance outcomes at the individual and organisational level of analysis. Data were obtained from 51 branches of a retail organisation in the United Kingdom. Results from structural equation modelling analysis revealed three salient findings. First, workplace spirituality was positively related to ethical climate, prosocial motivation, and moral judgment. Second, ethical climate partially mediated the relationship between workplace spirituality and prosocial motivation and moral judgment, respectively. Third, aggregated ethical climate significantly relates to branch-level helping behaviour and service performance.
Factor structure and psychometric properties of a Polish adaptation of the Frost Multidimensional Perfectionism Scale
Authors: Piotrowski Konrad , Bojanowska Agnieszka
Published: March 2019

The Frost Multidimensional Perfectionism Scale (FMPS) is one of the most popular questionnaires for measuring perfectionism. Although this scale is in common use, its psychometric parameters still remain in dispute. The aim of this article is to present the Polish adaptation of the FMPS in a non-clinical sample. 696 university students aged 18 to 42 (M = 26.74, SD = 7.56) took part in the study. Confirmatory Factor Analyses suggested that the most appropriate factor structure of the adapted version of the FMPS contains 5 correlated factors: CM (concerns over mistakes), DAA (doubts about actions), PE (parental expectations), PC (parental criticism), and PS (personal standards). The ORG (organization) subscale was removed after evaluation. The evaluation of the specific relationships of each dimension of the adapted version of the FMPS with shame, guilt, worry, rumination, and indecisiveness revealed that when controlling for the variances of the remaining dimensions, significant relationships occurred almost only in the case of the CM, DAA and PS scales, suggesting that they constitute the three core facets of perfectionism as measured by the FMPS.
Health Measurement and Health Inequality Over the Life Course: A Comparison of Self-rated Health, SF-12, and Grip Strength
Authors: Leopold Liliya
Published: March 2019

The cumulative (dis)advantage hypothesis predicts education differences in health to increase with age. All previous tests of this hypothesis were based on self-reported health measures. Recent research has suggested that self-reported health measures may not adequately capture differences in key analytical constructs, including education, age, cohort, and gender. In this study, I tested the cumulative (dis)advantage hypothesis using a self-reported subjective measure (self-rated health), a self-reported semi-objective measure (PCS based on SF-12), and an objective measure (grip strength) of general physical health. Hierarchical linear models applied to five waves of panel data (SOEP, 2006–2014, N = 3,635 individuals aged 25 to 83, comprising N = 9,869 person-years) showed large differences between health measures. Among men, education differences in both self-reported measures of health widened substantially with age, consistent with the cumulative (dis)advantage hypothesis. For grip strength, education differences were small and changed little with age, inconsistent with the hypothesis. Among women, education differences in both self-reported measures of health remained stable over the life course, but they widened substantially when measured by grip strength. I conclude that evidence on the cumulative (dis)advantage hypothesis is sensitive to the choice of a health measure.
The Effect of Training Pregnant Women and Their Husband’s on the Anxiety in Pregnant Women with Previous Adverse Pregnancy Outcomes: A Controlled Randomized Clinical Trial
Authors: Asgharian Bita , sehhatie Fahimeh , Mirghafourvand Mojgan
Published: March 2019

Pregnant women with previous adverse pregnancy outcomes have a higher level of anxiety, which creates several problems for the mother and the fetus/infant. Decreasing the anxiety in these pregnant women is therefore of great importance. The present study was conducted to evaluate the effect of training on the anxiety in women with previous adverse pregnancy outcomes. This randomized, controlled, clinical trial was conducted on 132 pregnant women with previous adverse pregnancy outcomes. The women were randomly assigned to training (n≤=≤66) and control (n≤=≤66) group. In the training group, women and their husbands received training sessions once a week, an instructional booklet and counseling on phone in the intervals between the sessions. The control group received routine treatment. Spielberger anxiety questionnaires were completed by the pregnant women before and 1 month after the intervention. Compared to the control group, significant reductions were observed in the state anxiety (adjusted mean difference -≤19.6, 95% CI -≤21.9 to -≤17.3, P≤ > 0.001) and trait anxiety (adjusted mean difference: - 20.1, 95% CI - 22.2 to - 17.9, P > 0.001) in the training group. Training pregnant women and their husbands with previous adverse pregnancy outcomes helps. This training should be added to the prenatal health care system.
Analysis and modelling of Reynolds stresses in turbulent bubbly up-flows from direct numerical simulations
Authors: du Cluzeau A. , Bois G. , Toutant A.
Published: March 2019

Two-phase bubbly flows are found in many industrial applications. These flows involve complex local phenomena that are still poorly understood. For instance, two-phase turbulence modelling is still commonly based on single-phase flow analyses. A direct numerical simulation (DNS) database is described here to improve the understanding of two-phase turbulent channel flow at a parietal Reynolds number of 127. Based on DNS results, a physical interpretation of the Reynolds stress and momentum budgets is proposed. First, surface tension is found to be the strongest force in the direction of migration so that budgets of the momentum equations suggest a significant impact of surface tension in the migration process, whereas most modelling used in industrial application does not include it. Besides, the suitability of the design of our cases to study the interaction between bubble-induced fluctuations (BIF) and single-phase turbulence (SPT) is shown. Budgets of the Reynolds stress transport equation computed from DNS reveal an interaction between SPT and BIF, revealing weaknesses in the classical way in which pseudoturbulence and perturbations to standard single-phase turbulence are modelled. An SPT reduction is shown due to changes in the diffusion because of the presence of bubbles. An increase of the redistribution leading to a more isotropic SPT has been observed as well. BIF is comprised of a turbulent (wake-induced turbulence, WIT) and a non-turbulent (wake-induced fluctuations, WIF) part which are statistically independent. WIF is related to averaged wake and potential flow, whereas WIT appears when wakes become unstable or interact with each other for high-velocity bubbles. In the present low gravity conditions, BIF is reduced to WIF only. A thorough analysis of the transport equations of the Reynolds stresses is performed in order to propose an algebraic closure for the WIF towards an innovative two-phase turbulence model.
How the turbulent/non-turbulent interface is different from internal turbulence
Authors: Elsinga G. E. , da Silva C. B.
Published: March 2019

The average patterns of the velocity and scalar fields near turbulent/non-turbulent interfaces (TNTI), obtained from direct numerical simulations (DNS) of planar turbulent jets and shear free turbulence, are assessed in the strain eigenframe. These flow patterns help to clarify many aspects of the flow dynamics, including a passive scalar, near a TNTI layer, that are otherwise not easily and clearly assessed. The averaged flow field near the TNTI layer exhibits a saddle-node flow topology associated with a vortex in one half of the interface, while the other half of the interface consists of a shear layer. This observed flow pattern is thus very different from the shear-layer structure consisting of two aligned vortical motions bounded by two large-scale regions of uniform flow, that typically characterizes the average strain field in the fully developed turbulent regions. Moreover, strain dominates over vorticity near the TNTI layer, in contrast to internal turbulence. Consequently, the most compressive principal straining direction is perpendicular to the TNTI layer, and the characteristic 45-degree angle displayed in internal shear layers is not observed at the TNTI layer. The particular flow pattern observed near the TNTI layer has important consequences for the dynamics of a passive scalar field, and explains why regions of particularly high scalar gradient (magnitude) are typically found at TNTIs separating fluid with different levels of scalar concentration. Finally, it is demonstrated that, within the fully developed internal turbulent region, the scalar gradient exhibits an angle with the most compressive straining direction with a peak probability at around 20$^{\text{o}}$. The scalar gradient and the most compressive strain are not preferentially aligned, as has been considered for many years. The misconception originated from an ambiguous definition of the positive directions of the strain eigenvectors.
Comments on Brugger and others (2018) ‘A quantitative comparison of microfossil extraction methods from ice cores’
Authors: FESTI DANIELA , KOFLER WERNER , OEGGL KLAUS
Published: March 2019

In our comments, we re-evaluate Brugger and others (2018) Lycopodium/Eucalyptus double marker approach, based on the fact that previous evidence already demonstrated that the batch of Eucalyptus tablets used by Brugger and others (2018) is not suitable for quantitative comparisons as they are characterized by inconsistent pollen concentration. We present clear evidence that the Eucalyptus tablets do feature inaccurate pollen concentrations, and are therefore improper for all quantitative comparisons of microfossil extraction methods. Consequently, the results of the quantitative and qualitative assessment of different pollen extraction methods from ice samples compiled by Brugger and others (2018) are highly questionable due to the use of faulty marker tablets.
Animal foods and postmenopausal breast cancer risk: a prospective cohort study
Authors: Marcondes Larissa Hansen , Franco Oscar H. , Ruiter Rikje , Ikram Mohammad Arfan , Mulder Marlies , Stricker Bruno H. , Kiefte-de Jong Jessica C.
Published: March 2019

The role of diet on breast cancer risk is not well elucidated but animal food sources may play a role through, for example, the pathway of the insulin-like growth factor 1 system or cholesterol metabolism. The aim of this study was to evaluate the association between animal foods and the risk of postmenopausal breast cancer. This study was embedded in the Rotterdam Study, a population-based prospective cohort study of subjects aged 55 years and over (61 % female). Dietary intake of different animal foods was assessed at baseline using a validated FFQ and adjusted for energy intake using the residual method. We performed Cox proportional hazards modelling to analyse the association between the intake of the different food sources and breast cancer risk after adjustment for socio-demographic, lifestyle and metabolic factors. During a median follow-up of 17 years, we identified 199 cases of breast cancer (6·2 %) among 3209 women. After adjustment for multiple confounders, no consistent association was found between the intake of red meat intake, poultry, fish or dairy products and breast cancer risk. However, we found that egg intake was significantly associated with a higher risk of breast cancer (hazard ratioQ4 v. Q1: 1·83; 95 % CI 1·20, 2·79; Ptrend=0·01). In conclusion, this study found that dietary egg intake but no other animal foods was associated with a higher risk of postmenopausal breast cancer. Further research on the potential mechanisms underlying this association is warranted.
Distribution of joints in the hinge-line culmination of foreland-verging overturned anticlines: an example from the Montagna dei Fiori structure in the Central Apennines of Italy
Authors: Francioni Mirko , Pace Paolo , Vitulli Milena , Sciarra Nicola , Calamita Fernando
Published: March 2019

The distribution of joints, veins and shear fractures in the Montagna dei Fiori overturned anticline is here reported. Two joint sets, longitudinal and transverse to the NNW–SSE anticline axial trend, and a conjugate system of shear fractures, are recognized. The transverse and longitudinal joint sets have a pre-folding development likely related to the foreland/foredeep flexure. The transverse joints were reopened during layer-parallel shortening along with the development of the shear fractures. Then, during syn-folding outer-arc extension and hinge-line culmination fold-axial parallel extension, both the longitudinal and transverse joints were enhanced and reactivated, respectively.
The humanitarian theatre: drought response during Ethiopia's low-intensity conflict of 2016
Authors: Desportes Isabelle , Mandefro Hone , Hilhorst Dorothea
Published: March 2019

This article aims to rekindle the debate on the politics of aid in the increasingly common – yet still under-studied – authoritarian and low-intensity conflict settings, detailing the case of Ethiopia in 2016, when a 50-year drought coincided with a wave of protests and a state of emergency. During four months of qualitative fieldwork in 2017, state, civil society, Ethiopian and international actors were approached – from humanitarian headquarters to communities in the Amhara, Oromiya and Somali regions. Research participants relayed stark discrepancies between the humanitarian theatre's ‘frontstage’, where disaster responders showcase an exemplary response, and its ‘backstage’, where they remove their frontstage masks and reflect on the information, the decision-making monopoly of the state and the intrusion of conflict dynamics into the humanitarian response. In humanitarian research and in policy, a collective conversation is necessary on where to draw the line between respect for governments’ sovereignty and the intrusion of humanitarian principles.
n-3 Fatty acids and risk for fatal coronary disease
Authors: Harris William S. , Zotor Francis B.
Published: March 2019

The purpose of this review is to consider the effects of the long-chain n-3 fatty acids found in marine foods, EPA and DHA, on risk for CVD, particularly fatal outcomes. It will examine both epidemiological and randomised controlled trial findings. The former studies usually examine associations between the dietary intake or the blood levels of EPA + DHA and CVD outcomes or, on occasion, total mortality. For example, our studies in the Framingham Heart Study and in the Women's Health Initiative Memory Study have demonstrated significant inverse relations between erythrocyte EPA + DHA levels (i.e. the Omega-3 Index) and total mortality. Recent data from the Cardiovascular Health Study reported the same relations between plasma phospholipid n-3 levels and overall healthy ageing. As regards randomised trials, studies in the 1990s and early 2000s were generally supportive of a cardiovascular benefit for fish oils (which contain EPA + DHA), but later trials were generally not able to duplicate these findings, at least for total CVD events. However, when restricted to effects on risk for fatal events, meta-analyses have shown consistent benefits for n-3 treatment. Taken together, the evidence is strong for a cardioprotective effect of EPA + DHA, especially when consumed in sufficient amounts to raise blood levels into healthy ranges. Establishing target EPA + DHA intakes to reduce risk for cardiovascular death is a high priority.
An Approximated, Control Affine Model for a Strawberry Field Scouting Robot Considering Wheel–Terrain Interaction
Authors: Menendez-Aponte Pablo , Kong Xiangling , Xu Yunjun
Published: March 2019

Recently, autonomous field robots have been investigated as a labor-reducing means to scout through commercial strawberry fields for disease detection or fruit harvesting. To achieve accurate over-bed and cross-bed motions, it is preferred to design the motion controller based on a precise dynamic model. Here, a dynamic model is developed for a custom-designed strawberry field robot considering terramechanic wheel–terrain interaction. Different from existing models, a torus geometry is considered for the wheels. In order to obtain a control affine model, the longitudinal force is curve-fitted using a polynomial function of the slip/skid ratio, while the lateral force is curve-fitted using an exponential function of both the slip/skid ratio and slip angle. An extended Kalman filter (EKF) is then developed to estimate the unknown parameters in the approximated model such that the state variables propagated by such a model can match experimental data. The approximated model and the EKF-based parameter estimation method are then validated in a commercial strawberry farm.
Cooperative Localisation of AUVs based on Huber-based Robust Algorithm and Adaptive Noise Estimation
Authors: Bo Xu , Razzaqi Asghar. A. , Yalong Liu
Published: March 2019

In this paper, adaptive noise estimation is used along with a previously proposed Huber-based robust algorithm for cooperative localisation of Autonomous Underwater Vehicles (AUVs). The Huber-based robust cooperative localisation algorithm named Huber-based Iterative Divided Difference Filtering (HIDDF), proposed in our previous work, effectively achieved a robust result against abnormal measurement noise, enhanced the stability of the filtering algorithm and improved the performance of cooperative localisation state estimation. However, its performance could be significantly further improved if it could estimate the system's noise statistical properties online in real time and then adaptively adjust the filtering gain matrix accordingly. In this paper, a novel adaptive noise estimation algorithm is proposed based on a covariance matching method. The proposed algorithm is suitable for adaptively estimating Gaussian and non-Gaussian measurement as well as process noise. The efficacy of the proposed algorithm has been verified through simulation results. In order to further verify the effectiveness of the proposed algorithm in practical systems, lake tests were conducted. Then, based on offline test data, the performance of the cooperative positioning algorithm under dual-pilot and single-pilot schemes was simulated. The advantages and feasibility of the algorithm are analysed and compared through performance comparison. Cooperative localisation accuracy of the previously proposed Huber-based robust algorithm has been enhanced significantly when used with the proposed adaptive noise estimation algorithm.
Review of Navigation and Positioning of Deep-sea Manned Submersibles
Authors: Zhang Tongwei , Tang Jialing , Qin Shengjie , Wang Xiangxin
Published: March 2019

Operational deep-sea manned submersibles are important underwater vehicles that provide strong technical support for international deep-sea research. Navigation and positioning technologies are expected to facilitate the complete exploitation of the scientific value of samples and data collected by such submersibles, improve their underwater operation efficiency and enhance their safety. This paper first briefly describes six operational deep-sea manned submersibles that can dive to depths of more than 4,500 m. Then, the paper focuses on the navigation and positioning technologies used in these submersibles. Finally, considering the existing problems in the navigation and positioning systems of China's manned submersibleJiaolong, the paper discusses future development trends of the navigation and positioning technologies used in operational deep-sea manned submersibles.
Using roaming behaviours of dogs to estimate contact rates: the predicted effect on rabies spread
Authors: Hudson Emily G. , Brookes Victoria J. , Ward Michael P. , Dürr Salome
Published: March 2019

Domestic dogs display complex roaming behaviours, which need to be captured to more realistically model the spread of rabies. We have previously shown that roaming behaviours of domestic dogs can be categorised as stay-at-home, roamer and explorer in the Northern Peninsular Area (NPA), Queensland, Australia. These roaming behaviours are likely to cause heterogeneous contact rates that influence the speed or pattern of rabies spread in a dog population. The aim of this study was to define contact spatial kernels using the overlap of individual dog utilisation distributions to describe the daily probability of contact between pairs of dogs exhibiting these three a priori roaming behaviours. We further aimed to determine if the kernels lead to different predicted rabies outbreaks (outbreak duration and number of rabid dogs) by incorporating the spatial kernels into a previously developed rabies spread model for the NPA. Spatial kernels created with both dogs in a pair being explorers or one dog explorer and one dog roamer (who roamed away from their residence) produced short but large outbreaks compared with spatial kernels with at least one stay-at-home dog. Outputs from this model incorporating heterogeneous contacts demonstrate how roaming behaviours influence disease spread in domestic dog populations.
Improving the success of InsurTech opportunities
Authors: Bruce D. , Avis C. , Byrne M. , Gosrani V. , Lim Z. , Manning J. , Popovic D. , Purcell R. , Qin W.
Published: March 2019

The Working Party has produced this report in order to prompt readers to engage at an early stage in InsurTech projects, through considering (i) the full range of risks associated with InsurTech developments, (ii) the lifecycle of an InsurTech venture and how any risk considerations may vary over this lifecycle and (iii) the extent to which InsurTech ventures align with risk strategy and risk appetite.

The report contains practical guidance for actuaries, risk professionals, insurance companies and their Boards on these considerations, and can be used to facilitate appropriate questioning, to help ensure that InsurTech-related business decisions are fully cognisant of the risk management issues and to help ensure the success of projects.

The Working Party developed this guidance having carried out an industry survey on a number of risk management topics relating to InsurTech, as well as having carried out interviews with a number of relevant senior stakeholders across the insurance industry, in order to better understand current sentiment and how risk management plays a part when considering opportunities in InsurTech. The Working Party views on the findings from these activities are summarised in the report.
Crickets and grasshoppers (Orthoptera) from the latest Eocene of the Isle of Wight, southern England, UK
Authors: GOROCHOV Andrej V.
Published: March 2019

All taxa of Orthoptera known from the latest Eocene deposits of the Isle of Wight are redescribed or discussed, based on the study of their type material. The following new taxa are described:Ontogryllusgen. nov.,O. rossisp. nov. (type species),Achetomorphagen. nov.,A. irregularissp. nov. (type species), andProeneopterotrypusgen. nov. The latter genus is here proposed forPteroplistes danicusRust, described from the Palaeocene/Eocene of Denmark, as this find is important for understanding the systematic position of the genusEneopterotrypusZeuner. Remarks about the taxonomy of the taxa studied, age of these deposits, and ecology are given.
Associations Between Informal Caregivers’ Burden and	Educational Level
Authors: Oedekoven Monika , Amin-Kotb Katja , Gellert Paul , Balke Klaus , Kuhlmey Adelheid , Schnitzer Susanne
Published: March 2019

Abstract. We investigated the association between the education of informal caregivers’ (IC) and their physical and mental burden. We hypothesized that better-educated IC would have more resources available to manage the care situation and as a result show lower perceived burden. We conducted a population survey of 6,087 German residents aged 18+ years, 966 of whom reported to be IC. Results show that IC felt more often mentally than physically burdened. In the multivariate analyses, higher-educated IC did not have lower odds of feeling physically burdened than lower-educated IC, though they did have increased odds of feeling mentally burdened. The higher perceived mental burden of higher-educated IC may be related to fear of loss of self-fulfilment and autonomy. Support services should consider the mental burden of higher-educated IC and tailor their interventions accordingly.
Remarkable Control of Western Boundary Currents by Eddy Killing, a Mechanical Air‐Sea Coupling Process
Authors: Renault L. , Marchesiello P. , Masson S. , McWilliams J. C.
Published: March 2019

Western boundary currents (WBCs) are critical to Earth's climate. In the last decade, mesoscale air‐sea interactions emerged as an important factor of WBC dynamics. Recently, coupled models including the feedback of surface oceanic currents to the atmosphere confirmed the existence of a physical process called eddy killing, which may correct long‐lasting biases in the representation of WBCs by providing an unambiguous energy sink mechanism. Using ocean‐atmosphere coupled simulations of the Gulf Stream and the Agulhas Current, we show that eddy killing reduces the eddy‐mean flow interaction (both forward and inverse cascades) and leads to more realistic solutions. Model and data fluxes are in good agreement when the same coarse grid is used for their computation, although in this case they are underestimated. We conclude that the uncoupled approach is no longer suitable for continued ocean model improvement and discuss new formulations that should better account for air‐sea interactions.
Focal Mechanisms for Subcrustal Earthquakes Beneath the Gibraltar Arc
Authors: Santos‐Bueno Nerea , Fernández‐García Carlos , Stich Daniel , Mancilla Flor de Lis , Martín Rosa , Molina‐Aguilera Antonio , Morales Jose
Published: March 2019

Intermediate deep earthquakes are usually associated with active subduction, and show mostly dip‐slip faulting mechanisms aligned with the downgoing oceanic lithosphere. Forty‐two new focal mechanisms from 50‐ to 100‐km depth beneath the Gibraltar Arc and Alboran Sea show different characteristics. The most abundant solutions are strike‐slip mechanisms, in agreement with relative plate motion between Nubia and Eurasia. Additional reverse faulting mechanisms indicate compression in direction of absolute plate motion, reproducing the basal drag of the mantle on the hanging lithosphere. In turn, no signature of ongoing subduction was found. Migrated sections of P wave receiver functions suggest that a significant part of intermediate deep seismicity is produced within the stalled remnants of Jurassic age, oceanic lithosphere that once formed the connection between the Alpine Tethys and the central Atlantic and later has been buried beneath the Gibraltar Arc.
Extremely Late Onset of the 2018 South China Sea Summer Monsoon Following a La Niña Event: Effects of Triple SST Anomaly Mode in the North Atlantic and a Weaker Mongolian Cyclone
Authors: Liu Boqi , Zhu Congwen
Published: March 2019

The onset of South China Sea (SCS) summer monsoon (SCSSM) in June 2018 was extremely late following a La Niña event, indicating a breakdown in the traditional positive relationship between ENSO and SCSSM onset. Although the weaker western Pacific subtropical high in early May facilitated the SCSSM establishment, the persistent weaker Mongolian cyclone featured by an anomalous barotropic anticyclone over Northeast Asia during mid–late May dramatically postponed the SCSSM onset in 2018. This not only reduced upper‐tropospheric divergence over the SCS, which suppressed monsoon convection by attenuating the South Asian High, but cooled the mid–upper troposphere to decrease the in‐situ vertical easterly shear. The convection over the Maritime Continent was therefore trapped in the tropics, which further delayed the SCSSM onset via an enhanced local Hadley cell. It suggests a potential effect of triple SSTA mode in North Atlantic on the SCSSM onset by changing the mid‐latitudinal circulation.
Detecting Regional Modes of Variability in Observation‐Based Surface Ocean pCO2
Authors: Landschützer Peter , Ilyina Tatiana , Lovenduski Nicole S.
Published: March 2019

We use a neural network‐based estimate of the sea surface partial pressure of CO2 (pCO2) derived from measurements assembled within the Surface Ocean CO2 Atlas to investigate the dominant modes of pCO2 variability from 1982 through 2015. Our analysis shows that detrended and deseasonalized sea surface pCO2 varies substantially by region and the respective frequencies match those from the major modes of climate variability (Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation, multivariate ENSO index, Southern Annular Mode), suggesting a climate modulated air‐sea exchange of CO2. We find that most of the regional pCO2 variability is driven by changes in the ocean circulation and/or changes in biology, whereas the North Atlantic variability is tightly linked to temperature variations in the surface ocean and the resulting changes in solubility. Despite the 34‐year time series, our analysis reveals that we can currently only detect one to two periods of slow frequency oscillations, challenging our ability to robustly link pCO2 variations to climate variability.
The Two Diurnal Modes of Tropical Upward Motion
Authors: Ruppert James H. , Klocke Daniel
Published: March 2019

This study describes a new mechanism governing the diurnal variation of vertical motion in tropical oceanic heavy rainfall zones, such as the intertropical convergence zone. In such regions, the diurnal heating of widespread anvil clouds due to shortwave radiative absorption enhances upward motion in these upper layers in the afternoon. This radiatively driven ascent promotes an afternoon maximum of anvil clouds, indicating a diurnal cloud‐radiative feedback. The opposite occurs at nighttime: While rainfall exhibits a dominant peak at night‐early morning, the boundary layer rooted upward motion and latent heating tied to this peak are forced to be more bottom heavy by the nighttime anomalous radiative cooling at upper levels. This mechanism therefore favors the stratiform top‐heavy heating mode during daytime and suppresses it nocturnally. These diurnal circulation signatures arise from microphysical‐radiative feedbacks that manifest on the scales of organized deep convection, which may ultimately impact the daily mean radiation budget.
Spatiotemporal Variations of Ambient Concentrations of Trace Elements in a Highly Polluted Region of China
Authors: Liu Shuhan , Zhu Chuanyong , Tian Hezhong , Wang Yuxuan , Zhang Kai , Wu Bobo , Liu Xiangyang , Hao Yan , Liu Wei , Bai Xiaoxuan , Lin Shumin , Wu Yiming , Shao Panyang , Liu Huanjia
Published: March 2019

Anthropogenic emissions of trace elements (TEs) into the atmosphere have warranted global concern due to their adverse effects on human health and the ecosystem. We adapted the Weather Research and Forecasting (WRF) and Models‐3/Community Multiscale Air Quality (CMAQ) modeling system to predict the spatial and temporal concentrations of 11 TEs (arsenic, selenium, lead, cadmium, chromium, nickel, antimony, manganese, cobalt, copper, and zinc) in fine particulate matter (PM2.5) in January, April, July, and October of 2012 over Beijing, Tianjin, and Hebei (BTH) region of Northern China, one of the most polluted areas in China with frequent occurrences of haze episodes. A localized emission inventory that includes both conventional air pollutants and TEs established by our previous study was used in the model. Predicted concentrations of TEs were compared with observations collected at a site located in Beijing Normal University. The results show that arsenic, selenium, lead, copper, nickel, and zinc predictions better agree with observations made in both months. Manganese, antimony, and cobalt simulations display different abilities to reproduce observations between months. Chromium predictions have lower correlation coefficients. Cadmium predictions, similar to previous findings, show the least ability to reproduce observations. According to the model predictions, higher concentrations of TEs are primarily identified in the central and southern areas of the BTH region, and seasonally January sees the highest TEs. Potential causes for high concentrations of TEs were examined by evaluating emissions and contributions from major sources. Finally, specific countermeasures for emissions reduction of TEs were proposed.
Corrections of Radiosonde‐Based Precipitable Water Using Ground‐Based GPS and Applications on Historical Radiosonde Data Over China
Authors: Zhang Weixing , Lou Yidong , Cao Yunchang , Liang Hong , Shi Chuang , Huang Jinfang , Liu Wenxuan , Zhang Yong , Fan Binbin
Published: March 2019

The usage of radiosonde humidity data in climate studies and atmospheric reanalysis has been greatly hampered by the inhomogeneity issue mainly caused by radiosonde sensor changes. In this work, high‐quality precipitable water (PW) products derived from a national Global Positioning System (GPS) network in China covering the period from 1999 to 2015 were used to quantify errors in radiosonde‐derived PW products for different radiosonde types. Correlations between PW biases and factors including the station location, mean PW, weighted mean temperature (Tm), and solar elevation angle were carefully analyzed. Biases in PW products derived from the mechanical radiosondes (GZZ2, used at most stations before 2001) show strong correlations with the station elevation and Tm, and a PW correction model was then developed. For GTS1 and GTS1‐1 (widely used in current operational system), due to the unobvious correlations between PW biases and these factors, corrections were estimated as mean values of PW biases at all collocated stations. For GTS1‐2, GTS2(U)‐1, and TD2‐A (used at a few stations), subject to insufficient GPS‐radiosonde collocated stations, they are left uncorrected. The corrected radiosonde‐derived PW products (referred as Corr) were compared with the uncorrected products (referred as Raw) as well as PW products derived from the radiosonde data homogenized using the method proposed by Dai et al. (2011; referred as Dai, https://doi.org/10.1175/2010JCLI3816.1). Corr products show better agreements with GPS‐derived PW than Raw and Dai, and artificial significant decreasing PW trends in the recent two decades in Raw products were greatly reduced after applying the proposed corrections.
Analysis of Dual Nature of Heat Flux Predicted by Monin‐Obukhov Similarity Theory: An Impact of Empirical Forms of Stability Correction Functions
Authors: Srivastava Piyush , Sharan Maithili
Published: March 2019

The behavior of sensible heat flux H with stability parameter ζ in the stable atmospheric surface layer is analyzed within the framework of Monin‐Obukhov similarity theory (MOST). Using MOST equations, H is expressed as a function of ζ and wind shear ∂U/∂z. A systematic mathematical analysis is carried out to analyze the behavior of H with ζ utilizing the linear as well as various nonlinear empirical functional forms of the similarity functions. In case of linear form, for a given value of H, two different values of ζ along with the “downward heat flux maximum” with a unique critical point are found to occur. However, for the other selected empirical similarity functions, more than two values of ζ having the same magnitude of H may occur suggesting the existence of multiple critical points. Further, the observational variation of H with ζ is analyzed using data from three different sites. Data suggest the existence of two different stability regimes for the same magnitude of heat flux. However, the data do not support the existence of multiple values of ζ for the same magnitude of H, as predicted by MOST with the other selected empirical forms of similarity functions. This suggests that the phenomenon of existence of downward heat flux maximum, as predicted by MOST equations, depends on the functional form of the similarity functions, and it appears to break down for some selected empirical forms of similarity functions under very stable conditions.
Surface Meteorological Conditions and Boundary Layer Height Variations During an Air Pollution Episode in Nanjing, China
Authors: Yin J. , Gao C. Y. , Hong J. , Gao Z. , Li Y. , Li X. , Fan S. , Zhu B.
Published: March 2019

The evolution of planetary boundary layer (PBL) was investigated using observations from a laser ceilometer, an eddy covariance system, and an automatic meteorological station in the north of Nanjing city during an air pollution episode in 2016–2017 winter. Based on 7‐day observation under clean to polluted day, we recorded the temporal variations of backscatter signals observed by the ceilometer, and then intercompared the planetary boundary layer height (PBLH) retrieved from individual methods. The results show that backscatter signal gradient, standard deviation, and wavelet transform analysis methods generated similar PBLH values and PBL diurnal variation patterns. Moreover, the PBL structure varied diurnally, with distinct patterns corresponding to clean and polluted days. Based on these measurements, the relationships between PBLH, weather conditions, and contaminants were analyzed. Results show that on clean days, strong surface turbulence exchange makes the PBL fully developed and makes the PBLH increase sharply after sunrise, with a maximum of 1,483 m; on polluted days, stable synoptic conditions and the weaker wind speeds facilitated the accumulation of air pollutants, leading to smaller net surface radiation and weaker turbulence. Consequently, these conditions during polluted days led to lower PBLH values, which were typically less than 900 m.
Sensitivity of Simulated Aerosol Properties Over Eastern North America to WRF‐Chem Parameterizations
Authors: Crippa P. , Sullivan R. C. , Thota A. , Pryor S. C.
Published: March 2019

Aerosol properties and their climatic feedbacks are characterized by high uncertainty in both global and regional model simulations. We explore sources of uncertainty in the representation of aerosol properties using an ensemble of simulations performed at 24‐km resolution with WRF‐Chem over eastern North America. The sensitivity of aerosol optical depth (AOD) and near‐surface fine particle concentrations (PM2.5) to planetary boundary layer (PBL) and aerosol schemes (modal with secondary organic aerosol versus sectional but excluding secondary organic aerosol), as well as different emission inventories (National Emission Inventory [NEI] 2005 versus 2011) is examined. We quantify the spread among ensemble members with respect to the model setup and compute statistical metrics to identify the run configuration that exhibits greatest fidelity relative to observations of aerosol and meteorological properties. Use of the Modal Aerosol Dynamics Model for Europe/Secondary Organic Aerosol Model scheme leads to highest agreement with Moderate Resolution Imaging Spectroradiometer clear‐sky AOD observations particularly when the 2005 NEI is used (with either PBL scheme). These members exhibit small negative mean fractional bias over the simulation domain (<2%) and relatively high spatial correlation in summertime mean monthly AOD (>0.5). The aerosol scheme and NEI dominate the ensemble spread in AOD. Near‐surface PM2.5 is also dependent on PBL scheme and is best reproduced in runs adopting a sectional approach and emissions for 2011. Thus, WRF‐Chem configuration associated with highest agreement with AOD observations is not the same as for PM2.5, possibly reflecting the importance of columnar water vapor in dictating AOD or other unexplored uncertainties linking surface mass concentrations to column optical properties.
Hot Spots of Climate Extremes in the Future
Authors: Xu Lianlian , Wang Aihui , Wang Dan , Wang Huijun
Published: March 2019

A Regional Extreme Climatic Change Index (RECCI), simultaneously considering the changes in intensity, frequency and interannual variability of three major extreme climatic variables (i.e., precipitation, temperature and wind speed), is constructed to represent regional changes of climate extremes in response to global warming. First, the daily outputs from 13 models in the Coupled Model Intercomparison Project phase 5 project in both historical and future simulations under the Representative Concentration Pathway 8.5 scenario are used to compute the extreme climatic indices. Second, the RECCI is computed on both annual and seasonal time scales during three periods (i.e., 2016–2035, 2046–2065 and 2080–2099) over 26 subregions. Finally, the spatiotemporal change of the RECCI is investigated, and then, the 26 subregions are classified into four categories for each period. The first category with the largest RECCI value is very sensitive to global warming, which is called hot spots of climate extremes. The results show that most hot spots are not time invariant on annual and seasonal time scales with some exceptions. On the annual time scale, the Amazon Basin is the only persistent hot spot in all three periods. For the seasonal time scale in March‐April‐May, the climate extremes in the Amazon Basin always display the strongest responsiveness to global warming, and the Eastern Africa is the only persistent hot spot in June‐July‐August in three periods. Similar results are also found for the other two seasons and periods. In addition, the change in extreme temperature is crucial over the East Asia with change in frequency prominent.
Multicycle Dynamics of the Aksay Bend Along the Altyn Tagh Fault in Northwest China: 2. The Realistically Complex Fault Geometry
Authors: Duan Benchun , Liu Zaifeng , Elliott Austin J.
Published: March 2019

We study rupture behavior of the Aksay bend along the Altyn Tagh fault in northwest China over multiple earthquake cycles. A finite element method is used to numerically simulate spontaneous rupture during a coseismic process, and a viscoelastic model is used to analytically compute the fault stresses during an interseismic process. We find that the Aksay bend is an effective barrier to halt dynamically propagating ruptures from either side of the bend within a range of model parameters, with statistically only about 10% of ruptures jumping across the bend and propagating through almost the entire local fault system. Secondary complexities in fault geometry within the bend, in particular those portions that align relatively well with the regional strike of the fault system, play a critical role in these occasionally jumping ruptures. Well‐developed fault patches with shear stress close to shear strength allow dynamically propagating ruptures to penetrate into the bend and are more susceptible to the dynamic triggering that enables rupture to jump across the bend onto the other strand. We identify additionally nine large rupture scenarios with different occurrences, and most of them rupture one strand outside the bend with triggered slip on some portions of the same or the other strand within the bend. Slip rate distributions from the models show significantly reduced fault slip within the bend and a permanently locked portion on the south strand near the peak of the Altun Mountains. These findings have important implications for seismic hazard assessments of complex fault systems worldwide.
The Tectonics and Active Faulting of Haiti from Seismicity and Tomography
Authors: Possee Daniel , Keir Derek , Harmon Nicholas , Rychert Catherine , Rolandone Frédérique , Leroy Sylvie , Corbeau Jordane , Stuart Graham , Calais Eric , Illsley‐Kemp Finnigan , Boisson Dominique , Momplaisir Roberte , Prépetit Claude
Published: March 2019

Oblique convergence of the Caribbean and North American plates has partitioned strain across a major transpressional fault system that bisects the island of Hispaniola. The devastating MW 7.0, 2010 earthquake that struck southern Haiti, rupturing an unknown fault, highlighted our limited understanding of regional fault segmentation and its link to plate boundary deformation. Here we assess seismic activity and fault structures across Haiti using data from 33 broadband seismic stations deployed for 16 months. We use traveltime tomography to obtain relocated hypocenters and models of Vp and Vp/Vs crustal structure. Earthquake locations reveal two clusters of seismic activity. The first corresponds to aftershocks of the 2010 earthquake and delineates faults associated with that rupture. The second cluster shows shallow activity north of Lake Enriquillo (Dominican Republic), interpreted to have occurred on a north‐dipping thrust fault. Crustal seismic velocities show a narrow low‐velocity region with an increased Vp/Vs ratio (1.80–1.85) dipping underneath the Massif de la Selle, which coincides with a southward‐dipping zone of hypocenters to a depth of 20 km beneath southern Haiti. Our observations of seismicity and crustal structure in southern Haiti suggests a transition in the Enriquillo fault system from a near vertical strike‐slip fault along the Southern Peninsula to a southward‐dipping oblique‐slip fault along the southern border of the Cul‐de‐Sac‐Enriquillo basin. This result, consistent with recent geodetic results but at odds with the classical seismotectonic interpretation of the Enriquillo fault system, is an important constraint in our understanding of regional seismic hazard.
How Did We Miss This? An Upper Atmospheric Discovery Named STEVE
Authors: Gallardo-Lacourt Bea , Perry Gareth , Archer William , Donovan Eric
Published: March 2019

Captured unknowingly by scientific instruments for years, a sky phenomenon is finally brought to the attention of researchers by eagle-eyed citizen scientists.