Atmospheric Environment (v.41, #18)
Editorial board (i).
Effects of acid-washing filter treatment on quantification of aerosol organic compounds by Liming Yang; Jaehyun Lim; Liya E. Yu (3729-3739).
The tests of standard mixtures and four sets of atmospheric particulate samples showed that an acid-wash (AW) pretreatment of fluorocarbon-coated glass fiber filters prior to aerosol sampling enhanced the quantifiable organic compounds for more than 29% (or 66 ng m−3); in particular, 47–273 ng m−3 (21–366%) more water-soluble organic compounds (WSOCs) were measured. When the acid-pretreated filters were employed, up to nine more organic species were measured in the individual daily samples. Because the acid pretreatment reduced the metal contaminants in the glass fiber filters, using the AW filters for aerosol sampling allows higher extraction recoveries of organic compounds. Since the fingerprinting compounds were more accurately determined when the aerosol samples were collected on the AW filters, better assessment of emission sources and toxicity of air pollutants can be obtained.
Keywords: Filter pretreatment; Glass fiber filter; Recovery efficiency; Organic aerosol;
Laboratory study of cluster ions formation in H2SO4–H2O system: Implications for threshold concentration of gaseous H2SO4 and ion-induced nucleation kinetics by A. Sorokin; F. Arnold (3740-3747).
Ion-induced binary H2SO4–H2O nucleation is an important mechanism of aerosol formation in the atmosphere. Ions are created in the atmosphere mainly by galactic cosmic rays. The importance of ion-induced nucleation is recognized in some of the observed nucleation events in the background atmosphere. However, the predictions of current ion–aerosol models are highly uncertain mostly due to the lack of detailed experimental information concerning the thermodynamics and kinetics of ion clustering reactions. Here we continue the report of results of our laboratory experiments on the formation and growth of positive and negative cluster ions in H2SO4–H2O vapours in the flow reactor started in Wilhelm et al. [2004. Ion-induced aerosol formation: new insights from laboratory measurements of mixed cluster ions HSO4 −(H2SO4) a (H2O) w and H+ (H2SO4) a (H2O) w . Atmospheric Environment 38, 1735–1744] and Sorokin et al. [2006. Formation and growth of sulphuric acid–water cluster ions: experiments, modelling, and implications for ion-induced aerosol formation. Atmospheric Environment 40, 2030–2045]. The main attention is given to the definition of the concentration of gaseous sulphuric acid in experiment and also to some aspects of the kinetics of small cluster ions formation. The performed analysis has indicated a threshold concentration of gaseous sulphuric acid for binary homogeneous nucleation of at least about 1010 cm−3 at room temperature and low relative humidity.
Keywords: H2SO4 formation; H2SO4–H2O cluster ions; Ion-induced nucleation; Kinetics;
Isoprenoid emissions of trees in a tropical rainforest in Xishuangbanna, SW China by B. Wilske; K.-F. Cao; G. Schebeske; J.-W. Chen; A. Wang; J. Kesselmeier (3748-3757).
Isoprenoid emissions of eight tropical tree species of SE Asia were investigated using dynamic Teflon bag branch enclosures. Emission potentials of four species were considerably deviating from a previous report. Two species, Garcinia cowa and Celtis philippensis, emitted isoprene with standard emission factors, given as carbon on dry weight basis of 20.7 and 0.2 μ g g - 1 h - 1 , respectively, before the peak of the rainy season. After the peak of the rainy reason the standard emission changed to 17.5 and 0.7 μ g g - 1 h - 1 , respectively. The other six species emitted monoterpenes with low standard emission factors between < 0.1 and 0.5 μ g g - 1 h - 1 . Four out of five species investigated at two different times of the year showed seasonal differences in emission rates and composition. Total isoprenoid emissions were generally higher with new leaf flush than with aged leaves. Overall, the results suggest that better understanding of volatile organic compounds (VOC) emission from tropical species of SE Asia requires investigations that cover different seasons.
Keywords: Phytogenic VOC; Isoprene; Monoterpenes; Tropics; Seasonal patterns; Standard emission factors;
Source contributions to primary organic aerosol: Comparison of the results of a source-resolved model and the chemical mass balance approach by Timothy E. Lane; Robert W. Pinder; Manish Shrivastava; Allen L. Robinson; Spyros N. Pandis (3758-3776).
A source-resolved model has been developed to predict the contribution of different sources to primary organic aerosol concentrations. The model was applied to the eastern US during a 17 day pollution episode beginning on 12 July 2001. Primary organic matter (OM) and elemental carbon (EC) concentrations are tracked for eight different sources: gasoline vehicles, non-road diesel vehicles, on-road diesel vehicles, biomass burning, wood burning, natural gas combustion, road dust, and all other sources. Individual emission inventories are developed for each source and a three-dimensional chemical transport model (PMCAMx) is used to predict the primary OM and EC concentrations from each source. The source-resolved model is simple to implement and is faster than existing source-oriented models. The results of the source-resolved model are compared to the results of chemical mass balance models (CMB) for Pittsburgh and multiple urban/rural sites from the Southeastern Aerosol Research and Characterization (SEARCH) network. Significant discrepancies exist between the source-resolved model and the CMB model predictions for some of the sources. There is strong evidence that the organic PM emissions from natural gas combustion are overestimated. It also appears that the OM and EC emissions from wood burning and off-road diesel are too high in the Northeastern US. Other similarities and discrepancies between the source-resolved model and the CMB model for primary OM and EC are discussed along with problems in the current emission inventory for certain sources.
Keywords: Source apportionment; Organic matter; Elemental carbon; PMCAMx; Eastern US;
A regional modelling study of the high ozone episode of June 2001 in southern Ontario by G. Brulfert; O. Galvez; F. Yang; J.J. Sloan (3777-3788).
High ozone levels were observed in southern Ontario in the summer of 2001, particularly in June, when the observed maximum was 137 ppb at Long Point. Development of effective ozone abatement strategies to prevent such episodes requires acknowledge of the chemistry in the appropriate source regions. Comprehensive high-resolution Eulerian chemical transport models, when used with accurate emissions data and meteorology, can elucidate the atmospheric chemical and physical processes responsible for episodes like these. In this work, the MM5/SMOKE/CMAQ regional air quality modelling system was used to investigate the chemistry involved in ozone formation during the episode in question and also more generally in the target domain. Some of the important simulations were further developed using Taylor diagrams to explore the ozone background and understand the sensitivity of ozone to NO X and VOC concentrations. Results from an arbitrary reduction of road traffic are discussed, based on NO X and VOC species in the traffic emission inventory. The ozone production rate was extracted from the model and mapped for June 2001 to assist in the identification of the source regions contributing to the ozone episode.
Keywords: Regional air quality; Air pollution; Ozone; NO X ; VOC; Mobile emission;
The Portable In Situ Wind Erosion Laboratory (PI-SWERL): A new method to measure PM10 windblown dust properties and potential for emissions by V. Etyemezian; G. Nikolich; S. Ahonen; M. Pitchford; M. Sweeney; R. Purcell; J. Gillies; H. Kuhns (3789-3796).
A new device—the Portable In Situ Wind ERosion Lab (PI-SWERL)—for measuring the potential for wind erosion and dust emission from soil surfaces is described. The device uses an annular ring (inner diameter=39 cm, outer diameter=51 cm) that rotates 6 cm above the soil test surface. Dust and sand are mobilized by the shear created by the rotating ring. Dust concentrations within the chamber that encloses the annular ring are measured by light scattering, used as a surrogate for particulate matter mass concentrations. While the PI-SWERL does not realistically simulate natural wind erosion processes that are often driven by saltation, measurements with the device provide a robust index of wind erosion/dust emission potential. Compared to traditional field wind tunnels used for the same purpose, the PI-SWERL offers significant economy in size, portability, and ease of use.
Keywords: Windblown dust; Eolian processes; Emissions inventory; Fugitive dust; Wind tunnel;
Lead isotopes in rainfall collected by a sequential sampler in suburban Tokyo by Tadashi Shimamura; Satoe Iijima; Masato Iwashita; Michinari Hattori; Yuichi Takaku (3797-3805).
Sequential rainfall collections were obtained with a 1-mm precipitation interval at a suburban site in Tokyo. The lead–isotope composition of each fraction was precisely determined by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The results showed that lead isotopes clearly changed during a single rainfall event for all rainfall events investigated, and large variations were observed for three specific events. In these three events, the values of the lead isotopes in the initial stage of rainfall (wash-out stage) were similar to the so-called common lead. As precipitation proceeded, the lead isotopes tended to be more radiogenic, and in the later stage (rain-out stage) they were highly radiogenic (up to 206, 207, 208Pb/204Pb=29.26, 26.03, and 63.64, respectively). The source of lead in the rain-out stage completely differed from that in the wash-out stage for these events. A simple mixing model with two end members (rain-out lead and wash-out lead) could explain the isotopic variations. Preliminary trajectory analysis indicated that the highly radiogenic lead was emitted and transported from South-West China. Coal combustion could be a candidate for rain-out stage lead by a selective emission of radiogenic isotopes (206Pb, 207Pb, 208Pb). A selective emission mechanism is discussed. The origin of the wash-out lead may have been local and derived from a mixture of urban particulates, e.g., particles from automobile exhaust, city incinerators, roadside dust, and factory exhaust.
Keywords: Lead isotopes; Rainwater; Sequential sampling; Multiple collector ICP-MS;
Contributions of natural sources to high PM 10 and PM 2.5 events in the eastern Mediterranean by Mustafa Koçak; Nikos Mihalopoulos; Nilgün Kubilay (3806-3818).
In total 562 daily PM 10 and PM 2.5 samples were collected from April 2001 to April 2002 at a rural site (Erdemli) located on the coast of the Eastern Mediterranean. The annual mean PM 10 and PM 2.5 levels were 36.4 ± 27.8 and 9.7 ± 5.9 μ g m - 3 , respectively. PM 10 and PM 2.5 concentrations indicated orders of magnitude change from day to day ( PM 10 = 2 – 326 μ g m - 3 ; PM 2.5 = 0.5 – 28 μ g m - 3 ). The highest levels of PM 10 were observed during the transition period (March, April and May) due to mineral dust transported from North Africa and during winter due to sea spray generation. However, PM 2.5 levels exhibited higher concentrations during summer resulting from an enhanced production of secondary aerosols. The PM 2.5 / PM 10 ratio (0.25) and categorization of air mass back trajectories indicated that PM 10 at the study area is dominated by primary aerosol emissions (mineral dust particles from the Saharan Desert and sea salt particles from the Mediterranean Sea itself). During the whole sampling period 28 and 51 events exceeded the recommended maximum values of 50 and 15 μ g m - 3 for PM 10 and PM 2.5 , respectively. Source apportionment analysis indicated that PM 10 exceedances originated as a consequence of natural events (mineral dust ∼ 40 % ; sea salt ∼ 50 % ) whereas PM 2.5 exceedances were accounted primarily by pollution events (in 90% of the cases).
Keywords: Air quality; PM 10 and PM 2.5 ; Saharan dust; Eastern Mediterranean;
Isoprene emissions from boreal peatland microcosms; effects of elevated ozone concentration in an open field experiment by Päivi Tiiva; Riikka Rinnan; Toini Holopainen; Sami K. Mörsky; Jarmo K. Holopainen (3819-3828).
Boreal Sphagnum-dominated peatlands are known to emit isoprene in amounts comparable to emissions from boreal Picea abies-dominated forests. Due to its high reactivity, isoprene can affect the local climate. Increases in isoprene emission under elevated ozone concentration have been detected in a few plant species, but the effects at the ecosystem level are largely unknown. We investigated the isoprene emission from microcosms representing a boreal Sphagnum fen under long-term realistically elevated ozone concentration in open-field conditions. The vegetation of the microcosms was dominated by Sphagnum papillosum Lindb. moss with dense Eriophorum vaginatum L. growth. The mean standardised emissions of isoprene under ambient and elevated ozone concentrations in the growing season of 2005 were on average 1.016 mg m - 2 h - 1 , and 1.308 mg m - 2 h - 1 , respectively. In August 2004, they were 0.434 mg m - 2 h - 1 under ambient, and 0.509 mg m - 2 h - 1 under elevated ozone concentration. Elevated ozone concentration had no statistically significant overall effects on the isoprene emission, although isoprene emissions tended to vary more and were slightly higher under ozone exposure during the warmest weather conditions. The results are in accordance with earlier observations of substantial isoprene emissions from boreal peatlands. As isoprene emissions from peatlands can be increased by ozone during warm periods, further research addressing this issue is needed.
Keywords: Peatland; Isoprene; Sphagnum; Eriophorum; Tropospheric ozone;
An on-line analysis of reduced sulfur gases in the ambient air surrounding a large industrial complex by Ki-Hyun Kim; Eui-Chan Jeon; Youn-Seo Koo; Moon-Soon Im; Yong-Hoon Youn (3829-3840).
In this study, the concentrations of reduced sulfur compounds (RSC: H2S, CH3SH, DMS, and DMDS) were continuously measured from an odor monitoring station over a 4-month period (August–November 2005) using an on-line GC system. The hourly measurement data of RSC, collected along with some major aromatic VOCs (benzene, toluene, xylene, etc.), approached the sum of 1500; the mean for all hourly H2S was computed to be 295 ppt, while those of the others were seen at 7 (DMS), 1 (CH3SH), and 0.4 ppt (DMDS). When these RSC data were compared across two seasons and on a 24 h scale basis, the values for either the summer or nighttime periods were generally high relative to their counterparts in the fall and daytime. Analysis of these RSC data generally suggests that most RSCs occur at some ppt concentration ranges and that their values frequently fall below detection limits (DL) values (except for H2S). If the total number of effective data sets (i.e., above DL values) are compared to each other, the results tend to differ significantly between H2S and the others: the proportion of effective number was as high as 75% for H2S, while the others were very low (6% of DMS and even less than that for the others). The distributions of RSC were hence clearly distinguished from those of VOCs in that the determination of the latter was scarcely limited by the instrumental detectability. According to the present study, the H2S data exhibit strong potential as the malodor tracers, while those of the other RSCs are unlikely due to the limited detectability. The overall results of this study hence suggest that several factors which include the selection of target compounds, the location of the monitoring points, and the scale (or number) of total monitoring points should be considered simultaneously to effectively track down the odor occurrence patterns in areas near strong source processes.
Keywords: Malodor; Sulfur gas; VOC; Ambient air; On-line analysis; Industrial complex;
Determination of single particle mass spectral signatures from heavy-duty diesel vehicle emissions for PM2.5 source apportionment by Laura G. Shields; David T. Suess; Kimberly A. Prather (3841-3852).
The size and chemical composition of individual diesel exhaust particles were measured in order to determine unique mass spectral signatures that can be used to identify particle sources in future ambient studies. The exhaust emissions from seven in-use heavy-duty diesel vehicles (HDDVs) operating on a chassis dynamometer were passed through a dilution tunnel and residence chamber and analyzed in real time by aerosol time-of-flight mass spectrometry (ATOFMS). Seven distinct particle types describe the majority of particles emitted by HDDVs and were emitted by all seven vehicles. The dominant chemical types originated from unburned lubricant oil, and the contributions of the various types varied with particle size and driving conditions. A comparison of light-duty vehicle (LDV) exhaust particles with the HDDV signatures provide insight into the challenges associated with developing an accurate source apportionment technique and possible ways of how they may be overcome.
Keywords: Aerosol; Single particle mass spectrometry; Diesel; Chemical composition; Source apportionment;
Characterization of size-differentiated particle composition of ionic species between Taichung Harbor (TH) and WuChi Traffic (WT) near Taiwan Strait during 2004–2005 by Chih-Chung Wen; Guor-Cheng Fang (3853-3861).
The characteristics of the ionic species concentrations by using appropriate statistical analysis methods and ionic balance equation were investigated in this paper. Size-differentiated ambient air particulates (atmospheric particulate matter of total suspended particulate TSP), fine particle (particle matter with aerodynamical diameter <2.5 μm, PM2.5), coarse particle (particle matter with aerodynamical diameter 2.5–10 μm, PM2.5–10) were collected during March 2004–January 2005 in Taichung Harbor (TH) and WuChi Traffic (WT) near Taiwan Strait by using PS-1 sampler. The result indicated ionic species SO4 2− was both the main components on the TSP and fine particulates at TH and WT sampling sites, and the ionic species Ca2+ and NO3 − were both the main components on the coarse particulates at TH and WT sampling sites during sampling period. By using the method of ionic balance, the results indicated that sulfate is mostly neutralized by ammonia at TH and WT sampling sites in the coarse particle mode. On the contrary, NH4HSO4 is the dominant component in the fine particle mode at TH and WT sampling sites.
Keywords: PM2.5; PM2.5–10; Taichung Harbor; Ions balances;
Modeling particle dispersion and deposition in indoor environments by N.P. Gao; J.L. Niu (3862-3876).
Particle dispersion and deposition in man-made enclosed environments are closely related to the well-being of occupants. The present study developed a three-dimensional drift-flux model for particle movements in turbulent indoor airflows, and combined it into Eulerian approaches. To account for the process of particle deposition at solid boundaries, a semi-empirical deposition model was adopted in which the size-dependent deposition characteristics were well resolved. After validation against the experimental data in a scaled isothermal chamber and in a full-scale non-isothermal environmental chamber, the drift-flux model was used to investigate the deposition rates and human exposures to particles from two different sources with three typical ventilation systems: mixing ventilation (MV), displacement ventilation (DV), and under-floor air distribution (UFAD). For particles originating from the supply air, a V-shaped curve of the deposition velocity variation as a function of particle size was observed. The minimum deposition appeared at 0.1– 0.5 μ m . For supermicron particles, the ventilation type and air exchange rate had an ignorable effect on the deposition rate. The movements of submicron particles were like tracer gases while the gravitational settling effect should be taken into account for particles larger than 2.5 μ m . The temporal increment of human exposure to a step-up particle release in the supply air was determined, among many factors, by the distance between the occupant and air outlet. The larger the particle size, the lower the human exposure. For particles released from an internal heat source, the concentration stratification of small particles (diameter < 10 μ m ) in the vertical direction appeared with DV and UFAD, and it was found the advantageous principle for gaseous pollutants that a relatively less-polluted occupied zone existed in DV and UFAD was also applicable to small particles.
Keywords: Drift-flux model; Particles; Exposure; Dispersion; Deposition;
Atmospheric methane in the Mediterranean: Analysis of measurements at the island of Lampedusa during 1995–2005 by F. Artuso; P. Chamard; S. Piacentino; A. di Sarra; D. Meloni; F. Monteleone; D.M. Sferlazzo; F. Thiery (3877-3888).
Measurements of atmospheric methane and other greenhouse gases are routinely carried out at the island of Lampedusa (35.5°N, 12.6°E), in the Mediterranean Sea. The CH4 mixing ratio record obtained during the period June 1995–September 2005 shows a distinct annual cycle characterized by a maximum in March and a minimum in late summer. The cycle peak-to-peak amplitude is about 30 ppb. In the period of investigation the CH4 growth rate (GR) shows two positive peaks, the first in 1998 with 19 ppb yr−1, and the second at the end of 2001 with 14 ppb yr−1. A sharp minimum of −13 ppb yr−1 occurs in April 2000. The GR remains close to zero after mid-2002. The evolution of methane GR and global temperature anomaly appears well correlated (R=0.71). The methane removal by reaction with OH, acting both on a global and on smaller scales, seems to play a large role. Significant differences exist among the GR at stations located within or close to the Mediterranean basin, indicating that regional and smaller scale processes must be taken into account to explain the methane evolution. The weekly measurements have been combined with backward airmass trajectories to study the relationship between CH4 mixing ratio and transport. On average, the methane mixing ratio in airmasses from Eastern Europe is about 8 ppb higher than in airmasses from Western Europe, 15 ppb higher than in airmasses from oceanic regions, and about 20 ppb higher than in airmasses from Africa. Among the airmasses from Africa, those from Northern Algeria display the largest CH4 mixing ratio, possibly because of emissions from gas and oil production and leakage from the gas pipelines. A North-to-South latitude gradient in CH4 mixing ratio is also apparent.
Keywords: Atmospheric methane; Growth rate; Seasonal cycle; Latitude gradient;
Organochlorine pesticides in the atmosphere of Guangzhou and Hong Kong: Regional sources and long-range atmospheric transport by Jun Li; Gan Zhang; Lingli Guo; Weihai Xu; Xiangdong Li; Celine S.L. Lee; Aijun Ding; Tao Wang (3889-3903).
Organochlorine pesticides (OCPs) were measured in the atmosphere over the period of December 2003–December 2004 at four sampling sites in Guangzhou and Hong Kong. Gas phase and particle phase concentrations of 8 OCP species, including trans-chlordane (t-CHL), cis-chlordane (c-CHL), p,p′-DDT, p,p′-DDE, o,p′-DDT, α-endosulfan, α- and γ-hexachlorocyclohexane (HCH), were studied. OCPs were found predominantly in the gas phase in all seasons. t-CHL, c-CHL, o,p′-DDT, p,p′-DDT and α-endosulfan had significantly (p<0.001) higher concentrations than other OCPs, with mean values (gas+particle) typically ranging from 103 to 1440 pg m−3. In general, the concentrations of OCPs in summer were higher than that in winter, except for α-HCH which showed no clear seasonal pattern. Higher levels of γ-HCH and o,p′-DDT found in Guangzhou could be attributed to the present usage of lindane and dicofol in the Pearl River Delta (PRD) region. The very high concentrations of p,p′-DDT and α-endosulfan were observed at all sampling sites. The results of 7 days air back trajectory analysis indicated that the unusual high p,p′-DDT levels in summer in both cities could be related to the seasonal usage of DDT containing antifouling paints for fishing ships in the upwind seaports of the region. The high concentrations of α-endosulfan in winter in the study area suggested an atmospheric transport by the winter monsoon from the East China, where endosulfan is being used as insecticide in cotton fields. The consistency of the seasonal variation of concentrations and isomeric ratios of DDTs and α-endosulfan with the alternation of winter monsoon and summer monsoon suggested that the Asian monsoon plays an important role in the long-range atmospheric transport of OCPs.
Keywords: OCPs; HCH; DDT; Chlordane; Back trajectory; Hong Kong; Guangzhou; South China;
Atmospheric emissions from the Windscale accident of October 1957 by J.A. Garland; R. Wakeford (3904-3920).
Although it occurred nearly 50 years ago, the nuclear reactor fire of October 1957 at Windscale Works, Sellafield, England, continues to attract interest. Several attempts have been made to quantify the releases of radionuclides and their radiological consequences, but additional information and a re-analysis of meteorological data encourage a further examination of emissions. The limited instrumentation of the reactor provided little relevant information and, as in previous estimates, the discharges are deduced from environmental evidence, but here the recent meteorological analysis is used. The interpretation of the meteorological and environmental evidence requires both timing and quantity of the emitted radionuclides to be considered together.Significant fission product emission continued from about 15:00 or 16:00 on 10 October 1957 until noon the following day. There were two main peaks in discharge rate, during the evening and early hours and from roughly 06:00 until 10:30, and the amounts emitted during each of these periods were probably comparable.Iodine-131 (131I), caesium-137 (137Cs) and polonium-210 (210Po) activities dominated the radioactive emissions and there is sufficient environmental evidence for releases of these radionuclides to be estimated within a factor of about two. (Some additional 131I may have escaped in a chemical form that was not included in the estimate, but it appears likely that the fraction was small.) There is evidence that the plume extended further east than accepted in previous assessments and the estimates of quantities emitted have been increased to allow for this. For other radionuclides the environmental measurements were fewer and the uncertainties are greater.
Keywords: Sellafield; Radioactivity; Discharges; Radionuclides; Dispersion;
A study of the movement of radioactive material released during the Windscale fire in October 1957 using ERA40 data by C.A. Johnson; K.P. Kitchen; N. Nelson (3921-3937).
In October 1957 a fire in Pile Number 1, a nuclear reactor at the Windscale Works, Sellafield, resulted in the accidental release of radionuclides to the atmosphere. Previous studies have described the atmospheric transport of the resultant radioactive plume from its release on the Cumbrian coast of Northwest England to its passage across mainland Europe. Those past studies have suffered from uncertainties concerning the quantity and timing of emissions and meteorological conditions. Crabtree [1959. The travel and diffusion of the radioactive material emitted during the Windscale accident. Quarterly Journal of the Royal Meteorological Society 85, 362] initially produced estimates of plume transport based on weather observations and radiosonde profiles. Later, ApSimon et al. [1985. Long-range atmospheric dispersion of radioisotopes—I. The MESOS model. Atmospheric Environment 19(1), 99–111] based estimates of plume transport on trajectories calculated from weather charts. More recently, Nelson et al. [2006. A study of the movement of radioactive material discharged during the Windscale fire in October 1957. Atmospheric Environment, 40, 58–75] used a full three-dimensional dispersion model using digitised weather data from similar charts.This study aims to further reduce uncertainty in the plume's behaviour by using the latest available Numerical Weather Prediction Model reanalysis of meteorological data from the European Centre for Medium Range Weather Forecasts (ERA-40) coupled with current best estimates of the radioactive emissions profile. The results presented here generally support the findings of previous studies though an improvement in model comparisons against observational measurements has been found. The opportunity was also taken to extend the time horizon, and hence geographical coverage, of the modelled plume. It is considered that this paper presents the best estimate to date of the plume's behaviour.
Keywords: Dispersion model; Sellafield; NAME; Radioactivity; Accident;
Erratum to “Monitoring of atmospheric reduced sulphur compounds and their oxidation in two coastal landfill areas” by Sang-Keun Song; Zang-Ho Shon; Ki-Hyun Kim; Seong Cheon Kim; Yoo-Keun Kim; Jung-Kwon Kim (3938).
Erratum to “Adsorption of air pollutants on the grain surface of Japanese cedar pollen” by Yuji Okuyama; Kiyoshi Matsumoto; Hiroshi Okochi; Manabu Igawa (3939-3940).
Corrigendum to “It is premature to include non-CO2 effects of aviation in emission trading schemes” by Piers M. de F. Forster; Keith P. Shine; Nicola Stuber (3941).