bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biomass burning aerosols and the low-visibility events in Southeast Asia
Authors: Lee Hsiang-He , Bar-Or Rotem Z. , Wang Chien 
Published: January 2017

Abstract. Fires including peatland burning in Southeast Asia have become a major concern to the general public as well as governments in the region. This is because aerosols emitted from such fires can cause persistent haze events under certain weather conditions in downwind locations, degrading visibility and causing human health issues. In order to improve our understanding of the spatiotemporal coverage and influence of biomass burning aerosols in Southeast Asia, we have used surface visibility and particulate matter concentration observations, supplemented by decade-long (2003 to 2014) simulations using the Weather Research and Forecasting (WRF) model with a fire aerosol module, driven by high-resolution biomass burning emission inventories. We find that in the past decade, fire aerosols are responsible for nearly all events with very low visibility (< 7 km). Fire aerosols alone are also responsible for a substantial fraction of low-visibility events (visibility  < 10 km) in the major metropolitan areas of Southeast Asia: up to 39 % in Bangkok, 36 % in Kuala Lumpur, and 34 % in Singapore. Biomass burning in mainland Southeast Asia accounts for the largest contribution to total fire-produced PM2.5 in Bangkok (99 %), while biomass burning in Sumatra is a major contributor to fire-produced PM2.5 in Kuala Lumpur (50 %) and Singapore (41 %). To examine the general situation across the region, we have further defined and derived a new integrated metric for 50 cities of the Association of Southeast Asian Nations (ASEAN): the haze exposure day (HED), which measures the annual exposure days of these cities to low visibility (< 10 km) caused by particulate matter pollution. It is shown that HEDs have increased steadily in the past decade across cities with both high and low populations. Fire events alone are found to be responsible for up to about half of the total HEDs. Our results suggest that in order to improve the overall air quality in Southeast Asia, mitigation policies targeting both biomass burning and fossil fuel burning sources need to be implemented.
Comparison of measured brightness temperatures from SMOS with modelled ones from ORCHIDEE and H-TESSEL over the Iberian Peninsula
Authors: Barella-Ortiz Anaïs , Polcher Jan , de Rosnay Patricia , Piles Maria , Gelati Emiliano 
Published: January 2017

Abstract. L-band radiometry is considered to be one of the most suitable techniques to estimate surface soil moisture (SSM) by means of remote sensing. Brightness temperatures are key in this process, as they are the main input in the retrieval algorithm which yields SSM estimates. The work exposed compares brightness temperatures measured by the SMOS mission to two different sets of modelled ones, over the Iberian Peninsula from 2010 to 2012. The two modelled sets were estimated using a radiative transfer model and state variables from two land-surface models: (i) ORCHIDEE and (ii) H-TESSEL. The radiative transfer model used is the CMEM. Measured and modelled brightness temperatures show a good agreement in their temporal evolution, but their spatial structures are not consistent. An empirical orthogonal function analysis of the brightness temperature's error identifies a dominant structure over the south-west of the Iberian Peninsula which evolves during the year and is maximum in autumn and winter. Hypotheses concerning forcing-induced biases and assumptions made in the radiative transfer model are analysed to explain this inconsistency, but no candidate is found to be responsible for the weak spatial correlations at the moment. Further hypotheses are proposed and will be explored in a forthcoming paper. The analysis of spatial inconsistencies between modelled and measured TBs is important, as these can affect the estimation of geophysical variables and TB assimilation in operational models, as well as result in misleading validation studies.
Leguminous species sequester more carbon than gramineous species in cultivated grasslands of a semi-arid area
Authors: Liu Yu , Tian Fuping , Jia Pengyan , Zhang Jingge , Hou Fujiang , Wu Gaolin 
Published: January 2017

Abstract. The establishment of grasslands on abandoned cropland has been proposed as an effective method to mitigate climate change. In this study, five cultivated grasslands (three leguminous species and two gramineous species), one abandoned cropland, and one natural grassland were studied to examine how soil organic carbon (SOC) sequestration rate and sequestration efficiency change in a semi-arid area in China. Our results showed that leguminous grasslands had greater total biomass (above- and belowground biomass), SOC storage, SOC sequestration rate, and efficiency than gramineous grasslands, abandoned cropland, and natural grassland during the experimental period. The largest soil carbon (C) accumulation in leguminous grassland was mainly attributed to the capacity to incorporate C and the higher biomass production. Leguminous grasslands accumulated more SOC than gramineous grasslands by 0.64 Mg C ha−1 yr−1. The average SOC sequestration efficiency in leguminous grassland (1.00) was about 2 times greater than gramineous grassland (0.34). The results indicate that cultivated leguminous grassland sequestered more SOC with higher SOC sequestration efficiency than cultivated gramineous grassland in arid and semi-arid areas. Our results provide a reference for ecological management in arid and semi-arid areas.
Evaluation of single-band snow-patch mapping using high-resolution microwave remote sensing: an application in the maritime Antarctic
Authors: Mora Carla , Jiménez Juan Javier , Pina Pedro , Catalão João , Vieira Gonçalo 
Published: January 2017

Abstract. The mountainous and ice-free terrains of the maritime Antarctic generate complex mosaics of snow patches, ranging from tens to hundreds of metres. These can only be accurately mapped using high-resolution remote sensing. In this paper we evaluate the application of radar scenes from TerraSAR-X in High Resolution SpotLight mode for mapping snow patches at a test area on Fildes Peninsula (King George Island, South Shetlands). Snow-patch mapping and characterization of snow stratigraphy were conducted at the time of image acquisition on 12 and 13 January 2012. Snow was wet in all studied snow patches, with coarse-grain and rounded crystals showing advanced melting and with frequent ice layers in the snow pack. Two TerraSAR-X scenes in HH and VV polarization modes were analysed, with the former showing the best results when discriminating between wet snow, lake water and bare soil. However, significant overlap in the backscattering signal was found. Average wet-snow backscattering was −18.0 dB in HH mode, with water showing −21.1 dB and bare soil showing −11.9 dB. Single-band pixel-based and object-oriented image classification methods were used to assess the classification potential of TerraSAR-X SpotLight imagery. The best results were obtained with an object-oriented approach using a watershed segmentation with a support vector machine (SVM) classifier, with an overall accuracy of 92 % and Kappa of 0.88. The main limitation was the west to north-west facing snow patches, which showed significant error, an issue related to artefacts from the geometry of satellite imagery acquisition. The results show that TerraSAR-X in SpotLight mode provides high-quality imagery for mapping wet snow and snowmelt in the maritime Antarctic. The classification procedure that we propose is a simple method and a first step to an implementation in operational mode if a good digital elevation model is available.
The Impact of the Fracking Boom on Arab Oil Producers
Authors: Kilian Lutz 
Published: January 2017

ABSTRACT This article makes four contributions. First, it investigates the extent to which the U.S. fracking boom has caused Arab oil exports to decline since late 2008. Second, the article quantifies for the first time by how much the U.S. fracking boom has lowered the global price of oil. Using a novel econometric methodology, it is shown that in mid-2014, for example, the Brent price of crude oil was lower by $10 than it would have been in the absence of the fracking boom. Third, the article provides evidence that the decline in Saudi net foreign assets between mid- 2014 and August 2015 would have been reduced by 27% in the absence of the fracking boom. Finally, the article discusses the policy choices faced by Saudi Arabia and other Arab oil producers.
Vacinação contra influenza: conhecimentos, atitudes e práticas de idosos
Authors: Oliveira Adriana Delmondes de , Reiners Annelita Almeida Oliveira , Mendes Priscila Aguiar , Azevedo Rosemeiry Capriata Souza , Gaspar Ana Carolina Macri 
Published: January 2017

Objetivo: Investigar os conhecimentos, atitudes e práticas de idosos sobre a influenza e a vacina contra a doença. Metodologia: Estudo descritivo com 71 idosos entrevistados com o uso de questionário baseado em inquérito CAP (Conhecimento, Atitude e Práticas). Os dados foram coletados no período de fevereiro a abril de 2015 e analisados com base nas recomendações do Ministério da Saúde. Resultados: A maioria dos idosos conhece apenas algum sinal ou sintoma da influenza, acredita que a vacina reduz os sintomas e riscos de complicações da gripe, crê que, mesmo a tomando, pode gripar, mas não a considera um meio de prevenção da doença. Quase 77% dos idosos referem tomar a vacina. Conclusão: O conhecimento dos idosos em relação à influenza é insatisfatório, porém suas atitudes são favoráveis e, provavelmente, isso tenha influência sobre suas práticas positivas em relação à vacinação.
A EFETIVIDADE DO CONSELHO MUNICIPAL DE SAÚDE DE SANTANA DO LIVRAMENTO/RS: UMA ANÁLISE A PARTIR DAS LEIS Nº 8.080/1990 e 8.142/1990
Authors: Carvalho Patsy , Troian Alessandra , Goularte Jeferson Luis Lopes 
Published: January 2017

O presente estudo investiga a efetividade do Conselho Municipal de Santana do Livramento/RS, no que diz respeito à participação na gestão das políticas de saúde do município e nas competências que se atribuem ao Conselho. O objetivo é analisar a efetividade do Conselho Municipal de Saúde de Santana do Livramento/RS em relação as Leis nº 8.080/1990 e a nº 8.142/1990, que regem o Conselho. A pesquisa caracteriza como qualitativa, as técnicas de coleta de dados foram: pesquisa documental, entrevista, a partir de roteiros semiestruturados e observação não participante. A etapa da pesquisa documental consistiu na análise das legislações municipal do Conselho de Saúde. Foram entrevistados oito conselheiros titulares dos segmentos de usuário, trabalhador da saúde, prestador de serviço e governo, que compõem obrigatoriamente a plenária, sorteados aleatoriamente. A observação não participante se deu nas reuniões do Conselho. Na análise de dados obtidos foi utilizada uma aproximação da técnica de análise de conteúdo. Como resultado tem-se que o Conselho Municipal de Saúde não é efetivo, pois, se observou a dificuldade do Conselho cumprir com a legislação federal vigente quanto a composição, a paridade e o tempo de atuação dos conselheiros. A pesquisa também identificou que o conhecimento dos conselheiros sobre as competências do Conselho é insuficiente, uma vez que os mesmos acreditam que suas funções se limitam a fiscalização e não a proposição e o acompanhamento de políticas públicas.
Las ánforas de Brindisi en Hispania Citerior. Pautas de distribución y consumo
Authors: Carreras Monfort César , Martín Menéndez Albert , Pera Isern Joaquim , Rodrigo Requena Esther 
Published: January 2017

La presencia del ejército romano republicano en la Hispania Citerior ha sido difícil de reconocer en el pasado debido al error en la interpretación de algunos yacimientos y la falta de investigación sobre el tema. En los últimos años, se han realizado nuevas investigaciones sobre yacimientos romanos republicanos identificando pequeñas fortificaciones militares y asentamientos civiles itálicos relacionados con el ejército. Uno de los fósiles directores presentes en todos estos yacimientos es la cerámica itálica tanto fina como común y las ánforas. Precisamente, las ánforas de la Apulia constituyen uno de los fósiles directores poco estudiados; este artículo pretende llenar este vacío y mostrar su importancia como indicador del avance de las tropas romanas durante el momento de la conquista, su relación con las vías militares y su aprovisionamiento.
Water redistribution in experimentally deformed natural milky quartz single crystals—Implications for H2O‐weakening processes
Authors: Stünitz H. , Thust A. , Heilbronner R. , Behrens H. , Kilian R. , Tarantola A. , Fitz Gerald J. D. 
Published: January 2017

AbstractNatural quartz single crystals were experimentally deformed in two orientations: (1) ⊥ to one prism plane and (2) in O+ orientation at 900 and 1000°C, 1.0 and 1.5 GPa, and strain rates of ~1 × 10−6 s−1. In addition, hydrostatic and annealing experiments were performed. The starting material was milky quartz, which consisted of dry quartz with a large number of fluid inclusions of variable size up to several 100 µm. During pressurization fluid inclusions decrepitated producing much smaller fluid inclusions. Deformation on the sample scale is anisotropic due to dislocation glide on selected slip systems and inhomogeneous due to an inhomogeneous distribution of fluid inclusions. Dislocation glide is accompanied by minor dynamic recovery. Strongly deformed regions show a pointed broad absorption band in the ~3400 cm−1 region consisting of a superposition of bands of molecular H2O and three discrete absorption bands (at 3367, 3400, and 3434 cm−1). In addition, there is a discrete absorption band at 3585 cm−1, which only occurs in deformed regions and reduces or disappears after annealing, so that this band appears to be associated with dislocations. H2O weakening in inclusion‐bearing natural quartz crystals is assigned to the H2O‐assisted dislocation generation and multiplication. Processes in these crystals represent recycling of H2O between fluid inclusions, cracking and crack healing, incorporation of structurally bound H in dislocations, release of H2O from dislocations during recovery, and dislocation generation at very small fluid inclusions. The H2O weakening by this process is of disequilibrium nature because it depends on the amount of H2O available.
Development of a daytime cloud and haze detection algorithm for Himawari‐8 satellite measurements over central and eastern China
Authors: Shang Huazhe , Chen Liangfu , Letu Husi , Zhao Meng , Li Shenshen , Bao Shanhu 
Published: January 2017

AbstractCloud detection by passive satellite sensors is very challenging in hazy weather over China because the reflective characteristics of haze and clouds are very similar. Consequently, hazy areas tend to be mistaken as cloudy or clear areas by current cloud mask algorithms. The Advanced Himawari Imager (AHI) aboard Himawari‐8 is a multispectral Earth observation sensor with high temporal and spatial resolutions. A cloud and haze detection algorithm for AHI measurements is urgently needed for monitoring atmospheric pollution and its transport over China. This study presents the new Himawari‐8 Cloud and Haze Mask (HCHM) algorithm that classifies image pixels from central and eastern China into one of three categories: clear, cloudy, or hazy. Based on the observations that haze occurs near the ground and accumulates in low‐elevation plains and basins while clouds form at high altitudes, the proposed HCHM algorithm incorporates altitude information to adjust the thresholds used in the selected threshold tests to separate haze and cloud pixels. We find that combining auxiliary digital elevation model data with traditional indicators, such as the R0.86/R0.64, R0.86/R1.6, and BT11‐BT3.9, improves the accuracy of cloud and haze discrimination. The HCHM algorithm is applied to Himawari‐8 observations from August 2015, November 2015, January 2016, and May 2016 and validated against the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation vertical feature mask results. The validation shows that the average leakage rate, false alarm rate, and haze missing rate of the HCHM algorithm are 3.95%, 5.88%, and 4.17%, respectively.
Circulation controls on southern African precipitation in coupled models: The role of the Angola Low
Authors: Munday Callum , Washington Richard 
Published: January 2017

AbstractIn southern Africa, models from the latest Coupled Model Intercomparison Project produce a wide variety of rainfall climatologies. Differences between models in rainfall amount reach 70% in the rainy season (December–February; DJF), and the median model overestimates rainfall by between 15 and 40% throughout the annual cycle. This paper investigates the role of an understudied regional circulation feature, the Angola Low, in differentiating between model estimates of precipitation. In austral spring, the Angola Low is a heat low, driven by strong surface heating whereas in DJF it is more similar to a tropical low and is associated with moist instability. In the austral summer, we find that the simulated strength of the Angola Low is associated with between 40 and 60% of the intermodel variability in model mean rainfall across the subcontinent. The relationship is particularly strong along a northwest, southeast axis aligned from Angola down to the Mozambican Channel. Along this axis, models with stronger Angola Lows simulate enhanced, by up to 50 g kg−1 ms−1, northeasterly and northwesterly moisture transport. The enhanced southward moisture flux in models with relatively deep Angola Lows increases the rate of moisture convergence in central areas of the subcontinent and reduces moisture divergence across the Mozambican coast. The results highlight the need to better understand the links between the Angola Low and southern African rainfall and suggest that improving the simulation of the Angola Low can help to constrain model estimates of southern African rainfall.
Intercomparisons of marine boundary layer cloud properties from the ARM CAP‐MBL campaign and two MODIS cloud products
Authors: Zhang Zhibo , Dong Xiquan , Xi Baike , Song Hua , Ma Po‐Lun , Ghan Steven J. , Platnick Steven , Minnis Patrick 
Published: January 2017

AbstractFrom April 2009 to December 2010, the Department of Energy Atmospheric Radiation Measurement (ARM) program carried out an observational field campaign on Graciosa Island, targeting the marine boundary layer (MBL) clouds over the Azores region. In this paper, we present an intercomparison of the MBL cloud properties, namely, cloud liquid water path (LWP), cloud optical thickness (COT), and cloud‐droplet effective radius (CER), among retrievals from the ARM mobile facility and two Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products (Goddard Space Flight Center (GSFC)‐MODIS and Clouds and Earth's Radiant Energy System‐MODIS). A total of 63 daytime single‐layer MBL cloud cases are selected for intercomparison. Comparison of collocated retrievals indicates that the two MODIS cloud products agree well on both COT and CER retrievals, with the correlation coefficient R > 0.95, despite their significant difference in spatial sampling. In both MODIS products, the CER retrievals based on the 2.1 µm band (CER2.1) are significantly larger than those based on the 3.7 µm band (CER3.7). The GSFC‐MODIS cloud product is collocated and compared with ground‐based ARM observations at several temporal‐spatial scales. In general, the correlation increases with more precise collocation. For the 63 selected MBL cloud cases, the GSFC‐MODIS LWP and COT retrievals agree reasonably well with the ground‐based observations with no apparent bias and correlation coefficient R around 0.85 and 0.70, respectively. However, GSFC‐MODIS CER3.7 and CER2.1 retrievals have a lower correlation (R ~ 0.5) with the ground‐based retrievals. For the 63 selected cases, they are on average larger than ground observations by about 1.5 µm and 3.0 µm, respectively. Taking into account that the MODIS CER retrievals are only sensitive to cloud top reduces the bias only by 0.5 µm.
Seasonal variation of shallow‐to‐deep convection transition and its link to the environmental conditions over the Central Amazon
Authors: Zhuang Yizhou , Fu Rong , Marengo José A. , Wang Hongqing 
Published: January 2017

AbstractThis study aims to characterize the seasonal variation of the shallow‐to‐deep convection transition and understand how environmental conditions impact the behavior of this transition using data collected from the Observations and Modeling of the Green Ocean Amazon (GOAmazon) field campaign in the Central Amazon (Manaus). The diurnal cycle of the rain/cloud fraction shows that the wet season has more extensive shallow convection before the transition to deep convection with larger fractional coverage and rainfall; deep convection in the transition season is more intense and has higher vertical extension and a stronger updraft. Surface meteorology, atmospheric moisture, instability, and wind shear are contrasted for the shallow/congestus convection (SC) cases and the locally formed shallow‐to‐deep convection transition (LD) cases. The comparisons suggest that occurrence of the LD is generally promoted under the conditions of high atmospheric moisture and instability but has a weaker dependence on wind shear. The relative importance of these environmental controls also varies in different seasons: The dry and transition seasons require a deeper moist layer from the boundary layer to midtroposphere than the wet season; convective available potential energy (CAPE) is higher during the transition season, but it is a less important factor for shallow‐to‐deep convection transition than in other seasons; LD only has significantly larger wind shears than SC during the dry season.
Bulk sediment 14C dating in an estuarine environment: How accurate can it be?
Authors: Lougheed Bryan C. , Obrochta Stephen P. , Lenz Conny , Mellström Anette , Metcalfe Brett , Muscheler Raimund , Reinholdsson Maja , Snowball Ian , Zillén Lovisa 
Published: January 2017

AbstractDue to a lack of marine macrofossils in many sediment cores from the estuarine Baltic Sea, researchers are often forced to carry out 14C determinations on bulk sediment samples. However, ambiguity surrounding the carbon source pathways that contribute to bulk sediment formation introduces a large uncertainty into 14C geochronologies based on such samples, and such uncertainty may not have been fully considered in previous Baltic Sea studies. We quantify this uncertainty by analyzing bulk sediment 14C determinations carried out on densely spaced intervals in independently dated late‐Holocene sediment sequences from two central Baltic Sea cores. Our results show a difference of ~600 14C yr in median bulk sediment reservoir age, or R(t)bulk, between the two core locations (~1200 14C yr for one core, ~620 14C yr for the other), indicating large spatial variation. Furthermore, we also find large downcore (i.e., temporal) R(t)bulk variation of at least ~200 14C yr for both cores. We also find a difference of 585 14C yr between two samples taken from the same core depth. We propose that studies using bulk sediment 14C dating in large brackish water bodies should take such spatiotemporal variation in R(t)bulk into account when assessing uncertainties, thus leading to a larger, but more accurate, calibrated age range.