The Experts below are selected from a list of 57693 Experts worldwide ranked by ideXlab platform
Matt Smith - One of the best experts on this subject based on the ideXlab platform.
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Long Range Transport of ambrosia pollen to poland
Agricultural and Forest Meteorology, 2008Co-Authors: Matt Smith, Carsten Ambelas Skjoth, Dorota Myszkowska, Agnieszka Uruska, Malgorzata Puc, Alicja Stach, Z Balwierz, Kazimiera Chlopek, Krystyna PiotrowskaAbstract:The Long-Range Transport of Ambrosia pollen to Poland is intermittent and mainly related to the passage of air masses over the Carpathian and Sudetes mountains. These episodes are associated with hot dry weather, a deep Planetary Boundary Layer (PBL) in the source areas and winds from the south. Such episodes can Transport significant amounts of Ambrosia pollen into Poland. The study investigates Ambrosia pollen episodes at eight sites in Poland during the period 7th to 10th September 2005, by examining temporal variations in Ambrosia pollen and back-trajectories. PBL depths in the likely source areas were calculated with the Eta meteorological model and evaluated against the mountain heights. Considerable amounts of Ambrosia pollen were recorded at several monitoring sites during the night or early in the morning of the investigated period. Trajectory analyses shows that the air masses arriving at the Polish sites predominantly came from the south, and were in the Czech Republic, Slovakia and Hungary the previous day indicating these countries as potential source areas. We have shown the progress of Ambrosia plumes into Poland from the south of the country, probably from Slovakia and Hungary, and demonstrated how Lagrangian back-trajectory models and meteorological models can be used to identify possible Transport mechanisms of Ambrosia pollen from potential source regions.
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the Long Range Transport of birch betula pollen from poland and germany causes significant pre season concentrations in denmark
Clinical & Experimental Allergy, 2007Co-Authors: Carsten Ambelas Skjoth, Matt Smith, Alicja Stach, J Sommer, Jorgen BrandtAbstract:Background Birch pollen is highly allergic and has the potential for episodically Long Range Transport. Such episodes will in general occur out of the main pollen season. During that time allergy patients are unprotected and high pollen concentrations will therefore have a full allergenic impact. Objective To show that Denmark obtains significant quantities of birch pollen from Poland or Germany before the local trees start to flower. Methods Simultaneous observations of pollen concentrations and phenology in the potential source area in Poland as well as in Denmark were performed in 2006. The Danish pollen records from 2000-2006 were analysed for possible Long Range Transport episodes and analysed with trajectories in combination with a birch tree source map. Results In 2006 high pollen concentrations were observed in Denmark with bi-hourly concentrations above 500 grains/ m3 before the local trees began to flower. Poland was identified as a source region. The analysis of the historical pollen record from Copenhagen shows significant pre-seasonal pollen episodes almost every year from 2000-2006. In all episodes trajectory analysis identified Germany or Poland as source regions. Conclusion Denmark obtains significant pre-seasonal quantities of birch pollen from either Poland or Germany almost every year. Forecasting of birch pollen quantities relevant to allergy patients must therefore take into account Long-Range Transport. This cannot be based on measured concentrations in Denmark. The most effective way to improve the current Danish pollen forecasts is to extend the current forecasts with atmospheric Transport models that take into account pollen emission and Transport from countries such as Germany and Poland. Unless Long Range Transport is taken into account pre-seasonal pollen episodes will have a full allergic impact, as the allergy patients in general will be unprotected during that time.
Encarnacion Rodriguez - One of the best experts on this subject based on the ideXlab platform.
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analysis of Long Range Transport influences on urban pm10 using two stage atmospheric trajectory clusters
Atmospheric Environment, 2007Co-Authors: Rafael Borge, Julio Lumbreras, Sotiris Vardoulakis, Pavlos Kassomenos, Encarnacion RodriguezAbstract:Abstract There is evidence that Long-Range Transport of natural and/or anthropogenic particles can have a negative impact on urban air quality. Certain European cities may fail to comply with the currently implemented 24-h PM10 limit value due to the additional impact of remote sources of particles, which are not controllable at local level. For that reason, reliable methodologies identifying Long-Range Transport patterns and quantifying their contribution to urban PM10 levels are required. In this study, a two-stage clustering methodology was developed and applied to back trajectories arriving in three European cities: Athens, Madrid and Birmingham, which experience large, moderate and small numbers of daily PM10 episodes, respectively. The atmospheric trajectories used in this analysis were computed with HYSPLIT model (NOAA) for a 3-year period. The two-stage cluster analysis has the advantage of providing highly disaggregated trajectory clusters, which proved to correspond to significantly different PM10 levels. In the case of Madrid and Birmingham, clusters of trajectories originating from North Africa and continental Europe, respectively, were strongly associated with the highest PM10 levels recorded in selected monitoring stations. In Athens, Long-Range Transport patterns and trans-boundary influences were less evident, which highlighted the more substantial impact of local emission sources. Finally, two simple statistical indexes were proposed for assessing PM10 episodes associated with different clusters of trajectories. This study has established a practical methodology for examining the impact of Long-Range atmospheric Transport on local air quality, without resorting to high resource-demanding source apportionment techniques.
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analysis of Long Range Transport influences on urban pm10 using two stage atmospheric trajectory clusters
Atmospheric Environment, 2007Co-Authors: Rafael Borge, Julio Lumbreras, Sotiris Vardoulakis, Pavlos Kassomenos, Encarnacion RodriguezAbstract:There is evidence that Long-Range Transport of natural and/or anthropogenic particles can have a negative impact on urban air quality. Certain European cities may fail to comply with the currently implemented 24-h PM10 limit value due to the additional impact of remote sources of particles, which are not controllable at local level. For that reason, reliable methodologies identifying Long-Range Transport patterns and quantifying their contribution to urban PM10 levels are required. In this study, a two-stage clustering methodology was developed and applied to back trajectories arriving in three European cities: Athens, Madrid and Birmingham, which experience large, moderate and small numbers of daily PM10 episodes, respectively. The atmospheric trajectories used in this analysis were computed with HYSPLIT model (NOAA) for a 3-year period. The two-stage cluster analysis has the advantage of providing highly disaggregated trajectory clusters, which proved to correspond to significantly different PM10 levels. In the case of Madrid and Birmingham, clusters of trajectories originating from North Africa and continental Europe, respectively, were strongly associated with the highest PM10 levels recorded in selected monitoring stations. In Athens, Long-Range Transport patterns and trans-boundary influences were less evident, which highlighted the more substantial impact of local emission sources. Finally, two simple statistical indexes were proposed for assessing PM10 episodes associated with different clusters of trajectories. This study has established a practical methodology for examining the impact of Long-Range atmospheric Transport on local air quality, without resorting to high resource-demanding source apportionment techniques.
Kazuichi Hayakawa - One of the best experts on this subject based on the ideXlab platform.
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Long Range Transport of polycyclic aromatic hydrocarbons from china to japan
Atmospheric Environment, 2007Co-Authors: Xiaoyang Yang, Yumi Okada, Ning Tang, Siori Matsunaga, Kenji Tamura, Jinming Lin, Takayuki Kameda, Akira Toriba, Kazuichi HayakawaAbstract:Airborne particulate matter was collected at Wajima, on the Noto Peninsula, Ishikawa, Japan by a high-volume air sampler with a quartz filter every week from 17 September 2004 to 16 September 2005. Polycyclic aromatic hydrocarbons (PAHs) extracted from filters were analyzed by HPLC with fluorescence detection. The atmospheric concentrations of PAHs at Wajima were higher during the heating period of China (when coal is burned for heat) than during the no-heating period. A meteorological analysis indicated that the air samples collected in that heating period at Wajima were Transported mainly from Northeast China over the Japan Sea. Principal component analysis of nine PAHs indicated a Chinese origin of the PAHs. These results strongly suggest that the high-level PAHs detected at Wajima were the result of Long-Range Transport from China.
Martin Scheringer - One of the best experts on this subject based on the ideXlab platform.
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Long Range Transport of organic chemicals in the environment
Environmental Toxicology and Chemistry, 2009Co-Authors: Martin ScheringerAbstract:The Long-Range Transport (LRT) of organic chemicals in the environment is reviewed, with particular focus on the role of environmental fate and Transport models and the relationship between model results and field data. Results from generic multimedia box models, spatially resolved multimedia box models, and atmospheric Transport models are highlighted, including conceptual investigations of cold-trap effect and global fractionation as well as results for particular chemicals, such as hexachlorocyclohexanes, DDT, polychlorinated biphenyls, perfluoroocctanoic acid, and polybrominated diphenyl ethers. Comparison of model results to field data shows that in many cases environmental fate models provide a good description of the distribution dynamics observed in the field, with deviations between measured and modeled concentrations around a factor of five. Sorption to atmospheric aerosols as a key process influencing the LRT of semivolatile organic chemicals (SOCs) is discussed, and the need for more measurements of the aerosol–air partitioning of SOCs and of the reactivity of particle-bound chemicals is pointed out. Key findings from field campaigns measuring legacy persistent organic pollutants (POPs) as well as new POPs are summarized. Finally, the relationship between science and politics in the field of POPs is addressed. Research into the LRT of organic chemicals has always occurred in interaction with political activities aiming to reduce the emissions of POPs. Since the late 1990s, the Stockholm Convention and the Aarhus Protocol on POPs have formed an important political context for research concerning POPs; the implementation of these international treaties creates a demand for ongoing research into the LRT of organic chemicals.
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application of multimedia models for screening assessment of Long Range Transport potential and overall persistence
Environmental Science & Technology, 2006Co-Authors: Jorg Klasmeier, Maximilian Stroebe, Anne Christine Le Gall, Dik Van De Meent, Kathrin Fenner, Michael Matthies, Thomas E. Mckone, Matthew Macleod, Martin Scheringer, Frank WaniaAbstract:We propose a multimedia model-based methodology to evaluate whether a chemical substance qualifies as POP-like based on overall persistence (Pov) and potential for Long-Range Transport (LRTP). It relies upon screening chemicals against the Pov and LRTP characteristics of selected reference chemicals with well-established environmental fates. Results indicate that chemicals of high and low concern in terms of persistence and Long-Range Transport can be consistently identified by eight contemporary multimedia models using the proposed methodology. Model results for three hypothetical chemicals illustrate that the model-based classification of chemicals according to Pov and LRTP is not always consistent with the single-media half-life approach proposed by the UNEP Stockholm Convention and that the models provide additional insight into the likely Long-term hazards associated with chemicals in the environment. We suggest this model-based classification method be adopted as a complement to screening against de...
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application of multimedia models for screening assessment of Long Range Transport potential and overall persistence
Environmental Science & Technology, 2006Co-Authors: Jorg Klasmeier, Maximilian Stroebe, Anne Christine Le Gall, Dik Van De Meent, Kathrin Fenner, Michael Matthies, Thomas E. Mckone, Matthew Macleod, Martin Scheringer, Frank WaniaAbstract:We propose a multimedia model-based methodology to evaluate whether a chemical substance qualifies as POP-like based on overall persistence (Pov) and potential for Long-Range Transport (LRTP). It relies upon screening chemicals against the Pov and LRTP characteristics of selected reference chemicals with well-established environmental fates. Results indicate that chemicals of high and low concern in terms of persistence and Long-Range Transport can be consistently identified by eight contemporary multimedia models using the proposed methodology. Model results for three hypothetical chemicals illustrate that the model-based classification of chemicals according to Pov and LRTP is not always consistent with the single-media half-life approach proposed by the UNEP Stockholm Convention and thatthe models provide additional insight into the likely Long-term hazards associated with chemicals in the environment. We suggest this model-based classification method be adopted as a complement to screening against defined half-life criteria at the initial stages of tiered assessments designed to identify POP-like chemicals and to prioritize further environmental fate studies for new and existing chemicals.
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comparing estimates of persistence and Long Range Transport potential among multimedia models
Environmental Science & Technology, 2005Co-Authors: Kathrin Fenner, Maximilian Stroebe, Anne Christine Le Gall, Michael Matthies, Thomas E. Mckone, Matthew Macleod, Martin Scheringer, Andreas Beyer, Mark Bonnell, Jorg KlasmeierAbstract:Overall persistence (Pov) and Long−Range Transport potential (LRTP) of organic chemicals are environmental hazard metrics calculated with multimedia fate and Transport models. Since there are several models of this type, it is important to know whether and how different model designs (model geometry, selection of compartments and processes, process descriptions) affect the results for Pov and LRTP. Using a set of 3175 hypothetical chemicals covering a broad Range of partition coefficients and degradation half−lives, we systematically analyze the Pov and LRTP results obtained with nine multimedia models. We have developed several methods that make it possible to visualize the model results efficiently and to relate differences in model results to mechanistic differences between models. Rankings of the hypothetical chemicals according to Pov and LRTP are highly correlated among models and are largely determined by the chemical properties. Domains of chemical properties in which model differences lead to dif...
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Comparing estimates of persistence and Long-Range Transport potential among multimedia models
Environmental Science and Technology, 2005Co-Authors: Kathrin Fenner, Maximilian Stroebe, Michael Matthies, Thomas E. Mckone, Matthew Macleod, Martin Scheringer, Andreas Beyer, Mark Bonnell, Anne-christine Le Gall, Jorg KlasmeierAbstract:Overall persistence (P-ov) and Long-Range Transport potential (LRTP) of organic chemicals are environmental hazard metrics calculated with multimedia fate and Transport models. Since there are several models of this type, it is important to know whether and how different model designs (model geometry, selection of compartments and processes, process descriptions) affect the results for P., and LRTP. Using a set of 3175 hypothetical chemicals covering a broad Range of partition coefficients and degradation half-lives, we systematically analyze the P-ov and LRTP results obtained with nine multimedia models. We have developed several methods that make it possible to visualize the model results efficiently and to relate differences in model results to mechanistic differences between models. Rankings of the hypothetical chemicals according to P-ov and LRTP are highly correlated among models and are largely determined by the chemical properties. Domains of chemical properties in which model differences lead to different results are identified, and guidance on model selection is provided for model users.
Bernadett Weinzierl - One of the best experts on this subject based on the ideXlab platform.
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Saharan dust Long-Range Transport across the Atlantic studied by an airborneDoppler wind lidar and the MACC model
Atmospheric Chemistry and Physics, 2016Co-Authors: Fernando Chouza, Oliver Reitebuch, Angela Benedetti, Bernadett WeinzierlAbstract:Abstract. A huge amount of dust is Transported every year from north Africa into the Caribbean region. This paper presents an investigation of this Long-Range Transport process based on airborne Doppler wind lidar (DWL) measurements conducted during the SALTRACE campaign (June–July 2013), as well as an evaluation of the ability of the MACC (Monitoring Atmospheric Composition and Climate) global aerosol model to reproduce it and its associated features. Although both the modeled winds from MACC and the measurements from the DWL show a generally good agreement, some differences, particularly in the African easterly jet (AEJ) intensity, were noted. The observed differences between modeled and measured wind jet speeds are between 5 and 10 m s−1. The vertical aerosol distribution within the Saharan dust plume and the marine boundary layer is investigated during the June–July 2013 period based on the MACC aerosol model results and the CALIOP satellite lidar measurements. While the modeled Saharan dust plume extent shows a good agreement with the measurements, a systematic underestimation of the marine boundary layer extinction is observed. Additionally, three selected case studies covering different aspects of the Saharan dust Long-Range Transport aLong the west African coast, over the North Atlantic Ocean and the Caribbean are presented. For the first time, DWL measurements are used to investigate the Saharan dust Long-Range Transport. Simultaneous wind and backscatter measurements from the DWL are used, in combination with the MACC model, to analyze different features associated with the Long-Range Transport, including an African easterly wave trough, the AEJ and the intertropical convergence zone.
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Experimental studies on Long-Range Transport of aerosols in the troposphere
2005Co-Authors: Bernadett Weinzierl, Andreas Petzold, Markus Fiebig, Andreas MinikinAbstract:The presented work focuses on the experimental investigation of atmospheric aerosols of various origins. Main objectives are the characterisation of aerosols and their impact on climate. The first key topic is the effect of ageing and dilution of forest fire aerosol layers during Long-Range Transport from the U.S. to Europe and the transformation of anthropogenic aerosols from urban pollution during atmospheric Transport. For that purpose, observations from airborne measurements onboard the Falcon research-aircraft during the ITOP (Intercontinental Transport of Ozone and Precursors) field experiment in July 2004 are being analysed. The second key topic is the investigation of microphysical, optical and radiative properties of desert dust aerosols over source regions, as well as the modification of these dust properties during atmospheric Transport from the source region to the far field and mixing with biomass burning aerosols. Information on these properties of aerosols are very important for satellite validation purposes (ENVISAT, ESSP 3/CALIPSO), for meso- and global-scale models and essential for the assessment of the impact of desert dust on climate. The information on the effects of transformation and mixing processes during Long-Range Transport is urgently needed for an assessment of the impact of desert dust on the composition of the tropospheric aerosol and on heterogeneous chemical processes. To this aim, airborne in-situ measurements of desert dust aerosols in the vertical column over a source region and during Long-Range Transport will be carried out during the German SAMUM (SAharan Mineral dUst experiMent) project.
