bluuebunny/crossref_metadata_2025 huggingface dataset:
Clothes in Kazan Petty Bourgeoisie of the First Half of the 19 Century as a Marker of Sociocultural Identity
Authors: Bessonova Tatyana V. , Khanova Aigul F.
Published: March 2018

The article is devoted to the study of a Kazan philistine costume of the first half of the 19th century as an integral feature of social quality in the conditions of the class system. This period in Russian history is the time of transition to a bourgeois society, during which the views on fashion and beauty changed, which was reflected in the dress and appearance of people. The main source that allows to recreate a philistine image of that period is the description of the Kazan philistine property, drawn up during the transfer to the trusteeship or sold for debts. The analysis of archival materials, most of which were introduced into scientific circulation for the first time, made it possible to reconstruct a Russian petty bourgeois suit and to present a visual image of an ordinary citizen and the townspeople of the period under study. The approaches to the study of this issue are based on the methods used in microhistory and historical anthropology with the use of lexical-semantic analysis elements. The study showed that philistine clothing is a social marker reflecting the social-cultural identity of an urban commoner, taking into account gender and ethnic-confessional features. The costume of an urban commoner as a whole retained a traditional image for Russia, which was formed during the era prior to Peter I, which was reflected, among other things, in lexical archaisms. In the first half of the 19th century the social-cultural mentality of a petty bourgeois remained generally at the level of a class-based mentality.
Fashion TV and the Motivation of His Audience
Authors: Pavlushina Margarita I. , Dautova Rezida V.
Published: March 2018

The beginning of the 21st century is characterized not only by important historical events in the world, but also by the changes in value norms and priorities. Television, being the most mass and accessible means of information, reflects these changes directly or indirectly. One of the significant trends of modern media is the development of an entertainment segment, which is present on television in the form of special formats and a specialized content. It is necessary to create special conditions for the permanent demonstration of their events, symbols and samples for the development of fashion, as the reflection of public and cultural content and as the means of search for a person's identity. Television has such natural features that provide fashion industry a unique platform for the development of a global fashionable space and intercivilizational communication. Fashion-TV complements the television picture of the world, influencing the spread of fashion trends and the development of a certain culture of behavior and lifestyle among TV viewers. Fashion-TV, as the combination of specialized Fashion channels and TV projects dedicated to fashion and human beauty on Russian social, political and entertainment channels, is primarily the carrier of information about modern fashion trends in clothing that influences the change of a person social-cultural image. This article the hypothesis of modern fashion TV has a blurred target audience with pronounced gender characteristics and a developed motivation. The article presents the results of the study conducted on the basis of the Kazan Federal University for two years. 
Determining the numbers of a landscape architect species (Tapirus terrestris), using footprints
Authors: Moreira Danielle O. , Alibhai Sky K. , Jewell Zoe C. , da Cunha Cristina J. , Seibert Jardel B. , Gatti Andressa
Published: March 2018

Background

As a landscape architect and a major seed disperser, the lowland tapir (Tapirus terrestris) is an important indicator of the ecological health of certain habitats. Therefore, reliable data regarding tapir populations are fundamental in understanding ecosystem dynamics, including those associated with the Atlantic Forest in Brazil. Currently, many population monitoring studies use invasive tagging with radio or satellite/Global Positioning System (GPS) collars. These techniques can be costly and unreliable, and the immobilization required carries physiological risks that are undesirable particularly for threatened and elusive species such as the lowland tapir.

Methods

We collected data from one of the last regions with a viable population of lowland tapir in the south-eastern Atlantic Forest, Brazil, using a new non-invasive method for identifying species, the footprint identification technique (FIT).

Results

We identified the minimum number of tapirs in the study area and, in addition, we observed that they have overlapping ranges. Four hundred and forty footprints from 46 trails collected from six locations in the study area in a landscape known to contain tapir were analyzed, and 29 individuals were identified from these footprints.

Discussion

We demonstrate a practical application of FIT for lowland tapir censusing. Our study shows that FIT is an effective method for the identification of individuals of a threatened species, even when they lack visible natural markings on their bodies. FIT offers several benefits over other methods, especially for tapir management. As a non-invasive method, it can be used to census or monitor species, giving rapid feedback to managers of protected areas.
The antimalarial compound ELQ‐400 is an unusual inhibitor of the bc1 complex, targeting both Qo and Qi sites
Authors: Song Zehua , Iorga Bogdan I. , Mounkoro Pierre , Fisher Nicholas , Meunier Brigitte
Published: March 2018

Inhibitors of the mitochondrial respiratory chain cytochrome bc1 complex, such as the antimalarial atovaquone and ELQ‐300, and many well‐studied compounds, are classified as either Qo or Qi site inhibitors based on their site of action. Here, we investigated the site of action of ELQ‐400 that showed an unusual behaviour, being effective against parasites resistant to the Qo site inhibitor atovaquone or to the Qi site inhibitor ELQ‐300. Analysis of yeast mutants and comparison with atovaquone and other ELQs strongly suggest that ELQ‐400 targets both Qo and Qi sites. Dual site inhibition would be particularly efficient as it would lower the risk of acquired resistance. However, such compounds are seldom found, which could be explained by structural and mechanistic differences between the sites.
DNA methylation profiling reveals a pathological signature that contributes to transcriptional defects of CD34+CD15− cells in early chronic‐phase chronic myeloid leukemia
Authors: Maupetit‐Mehouas Stéphanie , Court Franck , Bourgne Céline , Guerci‐Bresler Agnès , Cony‐Makhoul Pascale , Johnson Hyacinthe , Etienne Gabriel , Rousselot Philippe , Guyotat Denis , Janel Alexandre , Hermet Eric , Saugues Sandrine , Berger Juliette , Arnaud Philippe , Berger Marc G.
Published: March 2018

Despite the high efficiency of tyrosine kinase inhibitors (TKI), some patients with chronic myeloid leukemia (CML) will display residual disease that can become resistant to treatment, indicating intraclonal heterogeneity in chronic‐phase CML (CP‐CML). To determine the basis of this heterogeneity, we conducted the first exhaustive characterization of the DNA methylation pattern of sorted CP‐CML CD34+CD15− (immature) and CD34−CD15+ (mature) cells at diagnosis (prior to any treatment) and compared it to that of CD34+CD15− and CD34−CD15+ cells isolated from healthy donors (HD). In both cell types, we identified several hundreds of differentially methylated regions (DMRs) showing DNA methylation changes between CP‐CML and HD samples, with only a subset of them in common between CD34+CD15− and CD34−CD15+ cells. This suggested DNA methylation variability within the same CML clone. We also identified 70 genes that could be aberrantly repressed upon hypermethylation and 171 genes that could be aberrantly expressed upon hypomethylation of some of these DMRs in CP‐CML cells, among which 18 and 81, respectively, were in CP‐CML CD34+CD15− cells only. We then validated the DNA methylation and expression defects of selected candidate genes. Specifically, we identified GAS2, a candidate oncogene, as a new example of gene the hypomethylation of which is associated with robust overexpression in CP‐CML cells. Altogether, we demonstrated that DNA methylation abnormalities exist at early stages of CML and can affect the transcriptional landscape of malignant cells. These observations could lead to the development of combination treatments with epigenetic drugs and TKI for CP‐CML.
The Influence of Sea Level Rise on the Regional Interdependence of Coastal Infrastructure
Authors: Wang Ruo‐Qian , Stacey Mark T. , Herdman Liv Muir Meltzner , Barnard Patrick L. , Erikson Li
Published: March 2018

Sea level rise (SLR) is placing both immediate and long‐term pressures on coastal communities to take protective actions. Projects in the United States, and in many locations throughout the world, generally involve local jurisdictions raising the elevation of shoreline protection elements, with limited or no analysis of the feedback between shoreline management decisions and the impacts to water levels regionally. Our study examines the impact of local shoreline development on regional flood risk and considers SLR scenarios up to 1.5 m using a large‐scale numerical model, as an example, for San Francisco Bay. Here we show that measures to prevent flooding along an embayment shoreline in one location or subregion may increase inundation elsewhere in the system. The network of interactions occurs not only within subbasins of the Bay but also across the greater geographic extent from one end of the Bay to the other, and local jurisdiction may have either reciprocal relationships with or asymmetric impacts on one other. Importantly, the nature of the interaction network is seen to evolve with SLR: interactions are purely subregional at current sea level but with higher sea level (e.g., 1 m of SLR), not only do the subregional interdependencies strengthen but also regional interdependences emerge.
The Role of External Inputs and Internal Cycling in Shaping the Global Ocean Cobalt Distribution: Insights From the First Cobalt Biogeochemical Model
Authors: Tagliabue Alessandro , Hawco Nicholas J. , Bundy Randelle M. , Landing William M. , Milne Angela , Morton Peter L. , Saito Mak A.
Published: March 2018

Cobalt is an important micronutrient for ocean microbes as it is present in vitamin B12 and is a co‐factor in various metalloenzymes that catalyze cellular processes. Moreover, when seawater availability of cobalt is compared to biological demands, cobalt emerges as being depleted in seawater, pointing to a potentially important limiting role. To properly account for the potential biological role for cobalt, there is therefore a need to understand the processes driving the biogeochemical cycling of cobalt and, in particular, the balance between external inputs and internal cycling. To do so, we developed the first cobalt model within a state‐of‐the‐art three‐dimensional global ocean biogeochemical model. Overall, our model does a good job in reproducing measurements with a correlation coefficient of >0.7 in the surface and >0.5 at depth. We find that continental margins are the dominant source of cobalt, with a crucial role played by supply under low bottom‐water oxygen conditions. The basin‐scale distribution of cobalt supplied from margins is facilitated by the activity of manganese‐oxidizing bacteria being suppressed under low oxygen and low temperatures, which extends the residence time of cobalt. Overall, we find a residence time of 7 and 250 years in the upper 250 m and global ocean, respectively. Importantly, we find that the dominant internal resupply process switches from regeneration and recycling of particulate cobalt to dissolution of scavenged cobalt between the upper ocean and the ocean interior. Our model highlights key regions of the ocean where biological activity may be most sensitive to cobalt availability.
The Impact of Parameterized Convection on Climatological Precipitation in Atmospheric Global Climate Models
Authors: Maher Penelope , Vallis Geoffrey K. , Sherwood Steven C. , Webb Mark J. , Sansom Philip G.
Published: March 2018

Convective parameterizations are widely believed to be essential for realistic simulations of the atmosphere. However, their deficiencies also result in model biases. The role of convection schemes in modern atmospheric models is examined using Selected Process On/Off Klima Intercomparison Experiment simulations without parameterized convection and forced with observed sea surface temperatures. Convection schemes are not required for reasonable climatological precipitation. However, they are essential for reasonable daily precipitation and constraining extreme daily precipitation that otherwise develops. Systematic effects on lapse rate and humidity are likewise modest compared with the intermodel spread. Without parameterized convection Kelvin waves are more realistic. An unexpectedly large moist Southern Hemisphere storm track bias is identified. This storm track bias persists without convection schemes, as does the double Intertropical Convergence Zone and excessive ocean precipitation biases. This suggests that model biases originate from processes other than convection or that convection schemes are missing key processes.
Seasonal and Temporal Variations of Field‐Aligned Currents and Ground Magnetic Deflections During Substorms
Authors: Forsyth C. , Shortt M. , Coxon J. C. , Rae I. J. , Freeman M. P. , Kalmoni N. M. E. , Jackman C. M. , Anderson B. J. , Milan S. E. , Burrell A. G.
Published: March 2018

Field‐aligned currents (FACs), also known as Birkeland currents, are the agents by which energy and momentum are transferred to the ionosphere from the magnetosphere and solar wind. This coupling is enhanced at substorm onset through the formation of the substorm current wedge. Using FAC data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment and substorm expansion phase onsets identified using the Substorm Onsets and Phases from Indices of the Electrojet technique, we examine the Northern Hemisphere FACs in all local time sectors with respect to substorm onset and subdivided by season. Our results show that while there is a strong seasonal dependence on the underlying FACs, the increase in FACs following substorm onset only varies by 10% with season, with substorms increasing the hemispheric FACs by 420 kA on average. Over an hour prior to substorm onset, the dayside currents in the postnoon quadrant increase linearly, whereas the nightside currents show a linear increase starting 20–30 min before onset. After onset, the nightside Region 1, Region 2, and nonlocally closed currents and the SuperMAG AL (SML) index follow the Weimer (1994, https://doi.org/10.1029/93JA02721) model with the same time constants in each season. These results contrast earlier contradictory studies that indicate that substorms are either longer in the summer or decay faster in the summer. Our results imply that, on average, substorm FACs do not change with season but that their relative impact on the coupled magnetosphere‐ionosphere system does due to the changes in the underlying currents.
Seismic Imaging of Lithosphere Structure and Upper Mantle Deformation Beneath East‐Central China and Their Tectonic Implications
Authors: Li Hongyi , Song Xiaodong , Lü Qingtian , Yang Xiaoyu , Deng Yangfan , Ouyang Longbin , Li Jiapeng , Li Xinfu , Jiang Guoming
Published: March 2018

We conduct a nonlinear joint inversion of receiver functions and surface waves to obtain the lithosphere structure in east‐central China. We also use SKS splitting measurements to evaluate upper mantle deformation. The velocity model reveals that, to the east of the North‐South Gravity Lineament, the crust and lithosphere are significantly thinned. Three extensive crustal/lithospheric thinning subregions are identified. This indicates that the lithospheric modification in east‐central China is nonuniform due to heterogeneity of lithospheric strength. Extensive crustal and lithospheric thinning probably occurs in some weak zones such as basin‐range junction belts and large faults. The structure beneath the Dabie orogenic belt is complex due to the collision between the North and South China Blocks during the Late Paleozoic‐Triassic. The Dabie orogenic belt is delineated by a thick crust with a midcrust low‐velocity zone and a two‐directional convergence in the lithospheric scale. The crust and uppermost mantle across the Tanlu fault exhibit a strong seismic velocity contrast, which suggests deep penetration of this lithospheric‐scale fault. Most of our splitting measurements show nearly E‐W trending fast polarization. The similar present‐day lithosphere structure and upper mantle deformation may imply that the eastern North China Craton and South China Block have been dominated by a common dynamic process since the Late Mesozoic. The westward subduction of the Philippine plate and the long‐range effects of the collision between the Indian and Eurasia plates during the Cenozoic may have also contributed to the present velocity structure and stress field of eastern China.
Retrieval of Elastodynamic Reflections From Passive Double‐Couple Recordings
Authors: Hartstra I. E. , Almagro Vidal C. , Wapenaar K.
Published: March 2018

Virtual Green's functions obtained by seismic interferometry (SI) can provide valuable reflectivity data that can complement tomographic inversion schemes. However, virtual reflections are affected by illumination irregularities that are typical of earthquake‐induced wavefields recorded by the receiver array. As a consequence, irregular source distributions, scattering (in case of suboptimal illumination), and complex source mechanisms can significantly disturb the retrieval of Green's function approximations by conventional SI methods. We introduce SI by full‐field multidimensional deconvolution (MDD) for elastodynamic wavefields as an alternative method to obtain body wave Green's functions under those typical circumstances. The advantage of this method compared to other MDD methods is that the kernel of its governing equation is exact. This alternative formulation of the kernel pertains to several advantages: the solution is less sensitive to artifacts and utilizes the free‐surface multiples in the data to estimate primary reflections. Moreover, the point spread function of the full‐field MDD method corrects more affectively for irregular illumination because it also addresses irregularities caused by scattering inside the medium. In order to compare full‐field MDD to existing SI methods, we model synthetic earthquake recordings in a subduction zone setting using an elastodynamic finite‐difference scheme with double couples of different orientations and peak frequencies. Our results show that SI by cross correlation suffers most under these circumstances. Higher‐quality reflections are obtained by the MDD methods, of which full‐field MDD involves the most stable inversion, and its results are least contaminated by artifacts.
Shear Versus Tensile Failure Mechanisms Induced by Sill Intrusions: Implications for Emplacement of Conical and Saucer‐Shaped Intrusions
Authors: Haug Ø. T. , Galland O. , Souloumiac P. , Souche A. , Guldstrand F. , Schmiedel T. , Maillot B.
Published: March 2018

Sills, saucer‐shaped sills, and cone sheets are fundamental magma conduits in many sedimentary basins worldwide. Models of their emplacement usually approximate the host rock properties as purely elastic and consider the plastic deformation to be negligible. However, many field observations suggest that inelastic damage and shear fracturing play a significant role during sill emplacement. Here we use a rigid plasticity approach, through limit analysis modeling, to study the conditions required for inelastic deformation of sill overburdens. Our models produce distinct shear failure structures that resemble intrusive bodies, such as cone sheets and saucer‐shaped sills. This suggests that shear damage greatly controls the transition from flat sill to inclined sheets. We derive an empirical scaling law of the critical overpressure required for shear failure of the sill's overburden. This scaling law allows to predict the critical sill diameter at which shear failure of the overburden occurs, which matches the diameters of natural saucer‐shaped intrusions' inner sills. A quantitative comparison between our shear failure model and the established sill's tensile propagation mechanism suggests that sills initially propagate as tensile fractures, until reaching a critical diameter at which shear failure of the overburden controls the subsequent emplacement of the magma. This comparison also allows us to predict, for the first time, the conditions of emplacement of both conical intrusions, saucer‐shaped intrusions, and large concordant sills. Beyond the application to sills, our study suggests that shear failure significantly controls the emplacement of igneous sheet intrusions in the Earth's brittle crust.
Insights Into the Stress Field Around Bárarbunga Volcano From the 2014/2015 Holuhraun Rifting Event
Authors: Spaans Karsten , Hooper Andrew
Published: March 2018

The two weeklong rifting event at Bárðarbunga volcano in 2014 led to the Holuhraun eruption, which produced 1.5 km3 of lava and was the largest in Iceland in over 200 years. Predicting when and where an intrusion will lead to eruption requires detailed knowledge of the underlying stress field. Previous studies have explained the dike propagation path with a model that includes a tectonically induced stress field set up by a uniform amount of plate spreading across a straight rift axis. Here we test this hypothesis by modeling the tractions acting on the dike walls, constrained by data from Global Navigation Satellite System and Interferometric Synthetic Aperture Radar. Our results show that the majority of the opening and shearing in the final two dike segments is due to stresses built up by plate spreading since the last eruption at Holuhraun, as expected, but that the tectonically induced stress magnitude must be much lower to explain the movement of the dike walls further south. This result implies that most of the tectonically induced stress beneath the ice cap has been released, presumably due to intrusions associated with the Bárðarbunga volcanic system and the nearby Grímsvötn volcanic system, which have not been detected due to their subglacial nature. Modeling of the 2014 Bárðarbunga rifting event therefore not only yields insights into the event but also provides a window into undetected volcanic activity in the past.
A Bayesian Approach to Estimating a Spatial Stress Pattern From P Wave First‐Motions
Authors: Iwata Takaki
Published: March 2018

This study presents a new statistical method to estimate a spatial stress pattern in the Earth's crust from P wave first‐motions. In this method, it is assumed that the orientation of a fault plane is distributed randomly with a uniform distribution and that the direction of fault slip is parallel to the direction of maximum shear stress on the fault plane. Under these two assumptions, the spatial stress pattern that fits the data set of P wave first‐motions is estimated with a smoothness constraint on the spatial variation of stress pattern. An advantage of this method is that it does not require the determination of the focal mechanisms of each event. This method was applied to synthetic data sets to demonstrate its performance. The estimated stress pattern agreed with that given in the generation of the data set if the given pattern changes smoothly in space. Then, the method was applied to the real data set that was taken from the aftershocks of the 2000 Western Tottori earthquake. The resulting stress pattern was consistent with that estimated in previous studies examining the same data set. Additionally, the spatial variation of stress rotation across the main fault was revealed. These applications show the validity and benefit of the new method.
Subduction Thermal Regime, Slab Dehydration, and Seismicity Distribution Beneath Hikurangi Based on 3‐D Simulations
Authors: Suenaga Nobuaki , Ji Yingfeng , Yoshioka Shoichi , Feng Deshan
Published: March 2018

The downdip limit of seismogenic interfaces inferred from the subduction thermal regime by thermal models has been suggested to relate to the faulting instability caused by the brittle failure regime in various plate convergent systems. However, the featured three‐dimensional thermal state, especially along the horizontal (trench‐parallel) direction of a subducted oceanic plate, remains poorly constrained. To robustly investigate and further map the horizontal (trench‐parallel) distribution of the subduction regime and subsequently induced slab dewatering in a descending plate beneath a convergent margin, we construct a regional thermal model that incorporates an up‐to‐date three‐dimensional slab geometry and the MORVEL plate velocity to simulate the plate subduction history in Hikurangi. Our calculations suggest an identified thrust zone featuring remarkable slab dehydration near the Taupo volcanic arc in the North Island distributed in the Kapiti, Manawatu, and Raukumara region. The calculated average subduction‐associated slab dehydration of 0.09 to 0.12 wt%/km is greater than the dehydration in other portions of the descending slab and possibly contributes to an along‐arc variation in the interplate pore fluid pressure. A large‐scale slab dehydration (>0.05 wt%/km) and a high thermal gradient (>4 °C/km) are also identified in the Kapiti, Manawatu, and Raukumara region and are associated with frequent deep slow slip events. An intraslab dehydration that exceeds 0.2 wt%/km beneath Manawatu near the source region of tectonic tremors suggests an unknown relationship in the genesis of slow earthquakes.
An Uncertainty Data Set for Passive Microwave Satellite Observations of Warm Cloud Liquid Water Path
Authors: Greenwald Thomas J. , Bennartz Ralf , Lebsock Matthew , Teixeira João
Published: March 2018

The first extended comprehensive data set of the retrieval uncertainties in passive microwave observations of cloud liquid water path (CLWP) for warm oceanic clouds has been created for practical use in climate applications. Four major sources of systematic errors were considered over the 9‐year record of the Advanced Microwave Scanning Radiometer‐EOS (AMSR‐E): clear‐sky bias, cloud‐rain partition (CRP) bias, cloud‐fraction‐dependent bias, and cloud temperature bias. Errors were estimated using a unique merged AMSR‐E/Moderate resolution Imaging Spectroradiometer Level 2 data set as well as observations from the Cloud‐Aerosol Lidar with Orthogonal Polarization and the CloudSat Cloud Profiling Radar. To quantify the CRP bias more accurately, a new parameterization was developed to improve the inference of CLWP in warm rain. The cloud‐fraction‐dependent bias was found to be a combination of the CRP bias, an in‐cloud bias, and an adjacent precipitation bias. Globally, the mean net bias was 0.012 kg/m2, dominated by the CRP and in‐cloud biases, but with considerable regional and seasonal variation. Good qualitative agreement between a bias‐corrected AMSR‐E CLWP climatology and ship observations in the Northeast Pacific suggests that the bias estimates are reasonable. However, a possible underestimation of the net bias in certain conditions may be due in part to the crude method used in classifying precipitation, underscoring the need for an independent method of detecting rain in warm clouds. This study demonstrates the importance of combining visible‐infrared imager data and passive microwave CLWP observations for estimating uncertainties and improving the accuracy of these observations.
A Variational Merging Approach to the Spatial Description of Environmental Variables
Authors: Ulloa Jacinto , Samaniego Esteban , Campozano Lenin , Ballari Daniela
Published: March 2018

High‐resolution images of environmental variables are highly valuable sources of information in research and environmental management. Obtaining spatially continuous information from ground observations is challenging due to the wide variety of factors that affect classical interpolation methods. While geostatistical methods have produced noteworthy results, they generally rely on important assumptions and strongly depend on the availability of observed data. In turn, satellite‐based or model‐based gridded images generally represent the global spatial structure of environmental variables but are subject to bias. With the objective of exploiting the benefits of both sources of information, we propose a new mathematical formulation to merge observed data with gridded images of environmental variables using partial differential equations in a variational setting. With a convenient functional, formed as the sum of two competing terms, two simultaneous goals are achieved: to improve the description of the spatial structure in maps generated by simple deterministic interpolation methods and to increase the reliability of satellite‐based or model‐based images. Either satellite‐based or model‐based information is included in a regularity term to provide the global spatial structure, while in situ data are included in a fidelity term. The resulting maps can be considered a merging of interpolated in situ data with satellite or model imagery. The method is first evaluated using simulated images generated by geostatistical simulation and then applied to actual temperature and precipitation data in selected regions in the Tropical Andes. The results indicate that the method is capable of generating realistic maps while performing well in terms of validation.
Time Series Forecasting of Air Quality Based On Regional Numerical Modeling in Hong Kong
Authors: Liu Tong , Lau Alexis K. H. , Sandbrink Kai , Fung Jimmy C. H.
Published: March 2018

Based on prevailing numerical forecasting models (Community Multiscale Air Quality [CMAQ] model , Comprehensive Air Quality Model with Extensions, and Nested Air Quality Prediction Modeling System) and observations from monitoring stations in Hong Kong, we employ a set of autoregressive integrated moving average (ARIMA) models with numerical forecasts (ARIMAX) to improve the forecast of air pollutants including PM2.5, NO2, and O3. The results show significant improvements in multiple evaluation metrics for daily (1–3 days) and hourly (1–72 hr) forecast. Forecasts on daily 1‐hr and 8‐hr maximum O3are also improved. For instance, compared with CMAQ, applying CMAQ‐ARIMA reduces average root‐mean‐square errors (RMSEs) at all stations for daily average PM2.5, NO2, and O3in the next 3 days by 14.3–21.0%, 41.2–46.3%, and 47.8–49.7%, respectively. For hourly forecasts in the next 72 hr, reductions in RMSEs brought by ARIMAX using CMAQ are 18.2% for PM2.5, 32.1% for NO2, and 36.7% for O3. Large improvements in RMSEs are achieved for nonrural PM2.5and rural NO2using ARIMAX with three numerical models. Dynamic hourly forecast shows that ARIMAX can be applied for forecast of 7‐ to 72‐hr PM2.5, 4‐ to 72‐hr NO2, and 4‐ to 6‐hr O3. Besides applying ARIMAX for NO2, we recommend a mixed forecast strategy to ARIMAX for normal values of PM2.5and O3and employ numerical models for outputs above 75th percentile of historical observations. Our hybrid ARIMAX method can combine the advantage of ARIMA and numerical modeling to assist real‐time air quality forecasting efficiently and consistently.
Regional Regime‐Based Evaluation of Present‐Day General Circulation Model Cloud Simulations Using Self‐Organizing Maps
Authors: Schuddeboom Alex , McDonald Adrian J. , Morgenstern Olaf , Harvey Mike , Parsons Simon
Published: March 2018

Global clusters are derived by applying the self‐organizing map technique to the Moderate Resolution Imaging Spectroradiometer cloud top pressure‐cloud optical thickness joint histograms. These cloud clusters are then used to classify Cloud Feedback Model Intercomparison Project Observation Simulator Package output from the HadGEM3 (Global Atmosphere version 7) atmosphere‐only climate model. Discrepancies in the Global Atmosphere version 7 representation of particular clusters can be established by examining the two sets of cluster's occurrence rate and radiative effect. The overall differences in the occurrence rates show major discrepancies in several of the clusters, resulting in a shift from five dominant clusters in Moderate Resolution Imaging Spectroradiometer (above 10% occurrence rate) to two dominant clusters in the model. A comparison of the geographic distributions of occurrence rate shows that the differences are strongly regional and unique to each cluster. While comparisons of the global mean longwave and shortwave cloud radiative effect (CRE) show strong agreement, examination of the CRE of individual cloud types reveals larger errors that highlight the role of compensating errors in masking model deficiencies. CRE data for each of the clusters is further partitioned into regions. This establishes that the bias associated with a cluster is highly variable globally, with no clusters showing consistent biases across all regions. Therefore, regional level phenomena likely play an important role in the creation of these errors.
Ash Metrics for European and Trans‐Atlantic Air Routes During the Eyjafjallajökull Eruption 14 April to 23 May 2010
Authors: Prata A. J. , Kristiansen N. , Thomas H. E. , Stohl A.
Published: March 2018

Metrics for the risk associated with the threat that airborne volcanic ash particles pose to commercial jet aircraft are presented using simulations based on a Lagrangian particle transport and dispersion model driven by satellite measurements for the Eyjafjallajökull volcanic eruption, Iceland, for the period 14 April to 23 May 2010. The study utilizes a four‐dimensional data set of simulated ash concentrations together with European and trans‐Atlantic air routes to determine metrics corresponding to the total mass intercepted (defined as the dose), the mass interception rate (the dose rate), and the concentration (the exposure) over time (the dosage) that a jet aircraft encounters along the air route. The methodology can be used as a logistical and flight planning tool in a forecast mode and also in hindcast mode to assess the extent of airline fleet exposure to ash following an eruption, thereby providing operators with information useful for flight safety.
Constructional Volcanic Edifices on Mercury: Candidates and Hypotheses of Formation
Authors: Wright Jack , Rothery David A. , Balme Matthew R. , Conway Susan J.
Published: March 2018

Mercury, a planet with a predominantly volcanic crust, has perplexingly few, if any, constructional volcanic edifices, despite their common occurrence on other solar system bodies with volcanic histories. Using image and topographical data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, we describe two small (<15‐km diameter) prominences with shallow summit depressions associated with volcanically flooded impact features. We offer both volcanic and impact‐related interpretations for their formation, and then compare these landforms with volcanic features on Earth and the Moon. Though we cannot definitively conclude that these landforms are volcanic, the paucity of constructional volcanic edifices on Mercury is intriguing in itself. We suggest that this lack is because volcanic eruptions with sufficiently low eruption volumes, rates, and flow lengths, suitable for edifice construction, were highly spatiotemporally restricted during Mercury's geological history. We suggest that volcanic edifices may preferentially occur in association with late‐stage, postimpact effusive volcanic deposits. The European Space Agency/Japan Aerospace Exploration Agency BepiColombo mission to Mercury will be able to investigate further our candidate volcanic edifices; search for other, as‐yet unrecognized edifices beneath the detection limits of MESSENGER data; and test our hypothesis that edifice construction is favored by late‐stage, low‐volume effusive eruptions.
Climate Forcing of Ripple Migration and Crest Alignment in the Last 400 kyr in Meridiani Planum, Mars
Authors: Fenton Lori K. , Carson Helen C. , Michaels Timothy I.
Published: March 2018

The plains ripples of Meridiani Planum are the first paleo‐aeolian bedforms on Mars to have had their last migration episode constrained in time (to ~50–200 ka). Here we test how variations in orbital configuration, air pressure, and atmospheric dust loading over the past 400 kyr affect bedform mobility and crest alignment. Using the National Aeronautics and Space Administration Ames Mars Global Climate Model, we ran a series of sensitivity tests under a number of different conditions, seeking changes in wind patterns relative to those modeled for present‐day conditions. Results indicate that enhanced sand drift potential in Meridiani Planum correlates with (1) high axial obliquity, (2) a longitude of perihelion (Lp) near southern summer solstice, and (3) a greater air pressure. The last pulse of westward plains ripple migration likely occurred during the most recent obliquity (relative) maximum, from 111 to 86 ka. At Lp coinciding with southern summer solstice, the Mars Global Climate Model produced a westward resultant drift direction, consistent with the observed north‐south plains ripple crest alignment. However, smaller superposed ripples, aligned NNE‐SSW, are consistent with a strengthened northern summer Hadley return flow, occurring when Lp coincided with northern summer solstice. The superposed NNE‐SSW ripples likely formed as the axial obliquity decreased during the last relative maximum and Lp swung toward northern summer, from 86 to 72 ka. The timeline of bedform activity supports the proposed sequence of CO2 sequestration in the south polar residual cap over the past 400 kyr.
Paleopole Reconstruction of Martian Magnetic Field Anomalies
Authors: Thomas Paul , Grott Matthias , Morschhauser Achim , Vervelidou Foteini
Published: March 2018

The crust of Mars shows strong remanent magnetization, which was likely acquired during the early phases of planetary evolution when a core dynamo still operated. The direction of the field responsible for magnetizing the crust holds clues to the working of the dynamo and the rotational dynamics of the planet. By analyzing individual crustal magnetic field anomalies and with the aid of additional assumptions, the field orientations can be reconstructed. We have implemented an Equivalent Source Dipole method to determine the main field orientation during magnetization, assuming that the considered anomalies are unidirectionally magnetized without making specific assumptions about the source geometry. The available data are fit in a least squares sense, and the method yields confidence intervals for the admissible paleopole locations. The method was applied to six crustal magnetic field anomalies, two of which require a south pole in the northern hemisphere, while three indicate a south pole in the southern hemisphere. This implies that polar reversals took place at least once in Martian history. Furthermore, one of the investigated anomalies requires a south pole at equatorial to midlatitudes, indicating that a significant amount of true polar wander must have occurred on Mars. Finally, tests with synthetic data indicate that admissible paleopole locations typically spread across at least 25% of the planet, which may partially explain the scatter found in previously published paleopole studies.
GEODAR Data and the Flow Regimes of Snow Avalanches
Authors: Köhler A. , McElwaine J. N. , Sovilla B.
Published: March 2018

GEOphysical flow dynamics using pulsed Doppler radAR (GEODAR), a custom radar system, images avalanches over the entire slope with high spatial and temporal resolution at the experimental test site Vallée de la Sionne in Switzerland. Between winter seasons 2009/2010 and 2014/2015, data have been acquired from 77 avalanches. These data sets describe a wide variety of avalanches, which we classify in terms of seven flow regimes and combinations thereof. These flow regimes expand on previous classifications, with four identifiable dense flow regimes (where interaction between granules and with the flow bed dominates dynamics) and two different dilute flow regimes (where interaction between snow particles and the air becomes dominant). There is a further regime identified where snow balls simply roll down the mountain. A cold dense regime and a warm shear regime behave like noncohesive granular flows with velocity shear throughout the flow. A sliding slab regime and a warm plug regime occur when cohesion dominates and causes the flow units to act as solid‐like objects sliding on a thin shear zone. An intermittent regime connects the cold dense regime with the suspension regime and is characterized by highly fluctuating density and surging activity. GEODAR enables localization of these flow regimes and transitions between them in time and space. We discuss flow regime transitions in terms of snow properties, topography, speed, and size of the avalanches. This paper also serves as a reference for the data set which is made publicly available and should prove to be an invaluable resource for the development of physically based avalanche models.
Bedrock Fracture Characteristics as a Possible Control on the Distribution of Surge‐Type Glaciers
Authors: Crompton Jeff W. , Flowers Gwenn E. , Stead Doug
Published: March 2018

Glacier surging has been studied extensively and is understood as a dynamic instability at the glacier bed. Yet an explanation for the heterogeneous distribution of surge‐type glaciers at the scale of a mountain range remains elusive. Here we investigate bedrock discontinuity properties in the basins of 16 surge‐type and nonsurge‐type glaciers in the St. Elias Mountains of Yukon, Canada. Using scaled photographs of bedrock outcrops at the margins of each glacier, we digitize traces of the bedrock discontinuities and with automated purpose‐built software, quantify discontinuity properties that are a function of length, orientation, and spacing of bedrock fractures. We obtain an unexpected result: outcrops in the basins of surge‐type glaciers are less fractured than those in the basins of nonsurge‐type glaciers. We hypothesize that the degree of bedrock fracture may control the extent and location of a clast‐rich till transition zone at the glacier bed. This zone would provide flow resistance conducive to the development of an ice reservoir and thus to surging behavior. To reconcile our observations with the global distribution of surge‐type glaciers, we speculate that surge‐type glaciers may occur in geological settings characterized by an intermediate range of bedrock fracture.
Quantifying the Effects of Snowpack on Soil Thermal and Carbon Dynamics of the Arctic Terrestrial Ecosystems
Authors: Lyu Zhou , Zhuang Qianlai
Published: March 2018

Snow insulation effects modify soil and carbon dynamics in northern middle to high latitudes (45°–90°N). This study incorporates these effects by introducing a snow model into an existing soil thermal model in a biogeochemistry modeling framework, the Terrestrial Ecosystem Model. The coupled model is used to quantify snow insulation effects on carbon and soil thermal dynamics in 45°–90°N region for the historical period (2003–2010) and the future period (2017–2099) under two climate scenarios. The revised model captures the snow insulation effects and improves the estimates of soil thermal dynamics and the land freeze‐thaw as well as terrestrial ecosystem carbon dynamics. Historical mean cold‐season soil temperature at 5 cm depth driven with satellite‐based snow data is 6.4°C warmer in comparison with the original model simulation. Frozen area in late spring is estimated to shrink mainly over eastern Siberia, in central to eastern Europe, and along southern Canada in November. During each nongrowing season in the historical period, 0.41 Pg more soil C is released due to warmer soil temperature estimated using the new model. During 2003–2010, the revised model estimates that the region accumulated 0.86 Pg less C due to weaker gross primary production, leading to a regional C loss at 0.19 PgC/year. The revised model projects that the region will lose 38–51% permafrost area by 2100 and continue to be a C source under the low‐emission scenario (Representative Concentration Pathway 2.6) but to be gradually transitioning into a weak sink in the latter half of the 21st century under the high‐emission scenario (Representative Concentration Pathway 8.5).
Sediment Fingerprinting Suggests Differential Suspended Particulate Matter Formation and Transport Processes Across Hydrologic Regimes
Authors: Rose L. A. , Karwan D. L. , Aufdenkampe A. K.
Published: March 2018

Sediment fingerprinting techniques are increasingly used to characterize the sources and transport processes of particulate materials in surface waters. However, consensus on the use of biologically labile compounds such as organic carbon and nitrogen for sediment fingerprinting remains elusive. We used multiple biogeochemical characteristics of suspended particulate material (SPM) to characterize the differences in formation and transport processes of these materials during storm events ranging in size from small seasonal rainfall events to hurricanes and tropical storms in a small mid‐Atlantic watershed. During storms, particle surface area, percent organic C, percent organic N, percent Fe, and percent Al of SPM decreased with increasing discharge; these contents were lowest during the extreme events Hurricane Sandy, Hurricane Irene, and Tropical Storm Lee. Conversely, SPM C:N values during these storms were among the highest of all samples, and C:N generally increased with discharge. End‐member mixing analysis indicated that organic matter and metal contents of SPM collected during high event flows were well described by materials collected from erosional source areas throughout the watershed, while SPM collected during low event flows fell outside of the end‐member mixing space. This suggests that physical transport processes govern SPM export primarily from surface and fluvial areas during high flows, while in‐stream biogeochemical processes become increasingly important contributors to SPM at lower flows.