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Polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in trees grown in pathless forests were analyzed to investigate their dispersal patterns in the atmosphere. The pg/g levels of 23 PCCD, 22 PCDF, and 54 PCB congeners were identified. The total amount of PCDDs in the red pine tree sample (95.8 pg/g) was approximately 7 times that in the beech tree sample (13.2 pg/g). The total amount of PCDFs in the red pine tree sample (71.1 pg/g) was also approximately 7 times that in the beech tree sample (11.1 pg/g). The total amounts of PCBs in the red pine tree and beech tree samples were 1,380 and 1,150 pg/g, respectively. The (Cl1-Cl3)-PCBs comprised 63.1 % and 67.6 % of total PCBs in the red pine and in the beech, respectively. The results of the present study indicate that PCDD/Fs and PCBs are transferred over long distances in the atmosphere and accumulated in the contamination-free areas. © Springer Science+Business Media New York 2014.

This study is based on the analysis of Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) data measured over Hyderabad, India during the years 2006-2008. Tropospheric profiles of O3 show clear seasonality with high and low values during the premonsoon and monsoon seasons, respectively. Analysis of back trajectory and fire count data indicates major roles for long-range transport and biomass burning in the seasonal variation of O3. Typically, lower levels of O3 in the monsoon season were due to the flow of marine air and negligible regional biomass burning, while higher levels in other seasons were due to transport of continental air. In the upper troposphere, relatively low levels of O3 during the monsoon and postmonsoon seasons were associated with deep convection. In the free troposphere, levels of O3 also show year-to-year variability as the values in the premonsoon of 2006 were higher by about 30 ppbv compared to 2008. The year-to-year variations were mainly due to transition from El Ni�o (2006) to La Ni�a (2008). The higher and lower levels of O 3 were associated with strong and weak wind shears, respectively. Typically, vertical variations of O3 were anticorrelated with the lapse rate profile. The lower O3 levels were observed in the stable layers, but higher values in the midtroposphere were caused by long-range transport. In the PBL region, the mixing ratio of O3 shows strong dependencies on meteorological parameters. The Chemistry Climate Model (CCM2) reasonably reproduced the observed profiles of O3 except for the premonsoon season. � 2014. American Geophysical Union. All Rights Reserved.

黄砂の長距離輸送モデルを開発した。数値モデルでは、10年間にわたる北部中国の飛散観測の気象台データの解析から得られた、黄砂の飛散プロセスの新しいモジュールを導入し、黄砂の粒径分布、微物理過程、乾性沈着、湿性沈着過程を詳細に記述したものである。数値モデルの検証のために、モデル結果は、1988年4月の東アジアでの黄砂大襲来時の中国の粉塵飛散報告や日本の5つの常時監視局の地上観測濃度と比較され、良い一致を見ている。この数値モデルを用いて、1998年4, 月15-16日北京で発生した泥雨のシミュレーションを行った。, A long-range transport model for yellow-sand is developed. A new module for mobilization process of yellow-sand is devised according to the analysis of observed mobilization data of meteorological stations in North China for ten years. The model considers the size spectrum of yellow-sand, the micro-physical process and the parameterization of dry and wet deposition in detail.For the model validation, the model results were compared with dust whirl reports of the synoptic weather code and with observed surface concentration at five stations in Japan for an intensive transport event of yellow-sand over East Asia in April 1988, showing a high degree of agreement. Then, by means of the present model, a heavy muddy rain in Beijing during April 15-16, 1998 is simulated successfully.

Biomass burning is one of the most important sources of organic matter in the atmosphere as it affects the absorption and scattering of solar radiation, creates cloud condensation nuclei and possibly influences ice and snow albedo. Here we created and validated an analytical method using HPLC/(-)-ESI-MS/MS to determine phenolic compounds (PCLCs): vanillic acid, isovanillic acid, homovanillic acid, syringic acid, syringaldehyde, ferulic acid, p-coumaric acid, and coniferyl aldehyde at trace levels in particulate matter. We analyzed eighteen high-volume air samples from Ny Alesund (Svalbard) collected during the boreal spring and summer of 2010. Biomass burning molecules including PCLCs (

National audience; Climate change and air quality are closely related: through the policy measures implemented to mitigate these major environmental threats but also through the geophysical processes that drive them. We designed, developed and implemented a comprehensive regional air quality and climate modelling system to investigate future air quality in Europe taking into account the combined pressure of future climate change and long range transport. Using the prospective scenarios of the last generation of pathways for both climate change (emissions of well mixed greenhouse gases) and air pollutants, we can provide a quantitative view into the possible future air quality in Europe. We find that ozone pollution will decrease substantially under the most stringent scenario but the efforts of the air quality legislation will be adversely compensated by the penalty of global warming and long range transport for the business as usual scenario. For particulate matter, the projected reduction of emissions efficiently reduces exposure levels.; Changement climatique et qualité de l'air sont intimement liés : à travers les politiques de gestion mises en oeuvre pour atténuer ces menaces environnementales majeures mais aussi à travers les processus géophysiques qui les gouvernent. Afin de pouvoir étudier l'évolution de la pollution atmosphérique en Europe en prenant en compte l'influence conjointe du changement climatique et du transport à longue distance, nous avons conçu, développé et mis en oeuvre un système complet de modélisation régionale du climat et de la qualité de l'air. En utilisant des scénarios prospectifs de dernière génération relatifs au changement climatique (émissions de gaz à effet de serre) mais aussi pour les polluants à courte durée de vie, nous avons pu proposer une quantification de l'évolution future de la qualité de l'air en Europe. D'après le scénario le plus volontariste, la pollution liée à l'ozone sera réduite de manière substantielle mais les efforts positifs induits par les politiques de gestion de la qualité de l'air seront contrebalancés par le changement climatique et le transport à longue distance pour le scénario statu-quo. En ce qui concerne les particules, les réductions d'émissions futures réduiront de manière efficace les niveaux d'exposition.

Bulk atmospheric deposition samples were taken every two months for a year in 2009-2010 at two sites in northern Sweden and analyzed for a suite of legacy and emerging persistent organic chemicals including legacy organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and novel flame retardants (NFRs). To further investigate the urban occurrence and contribution to remote contamination of flame retardants, indoor air, ventilation system air, and dust were sampled in several microenvironments in Stockholm during the winter of 2012 for analysis of PBDEs, isomer-specific hexabromocyclododecane (HBCDD), and NFRs. Outdoor air and soil samples were also sampled around the same time period for analysis of the same compounds. Five emerging pollutants were detected in atmospheric deposition: the current-use pesticides trifluralin and chlorothalonil; and the NFRs 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), 1,2-bis(tribromophenoxy)ethane (BTBPE), and Dechlorane Plus (DP). A decrease in the fraction of the anti isomer of DP was observed at the more remote site, indicating isomer-selective degradation or isomerization during long range atmospheric transport. The more remote site also received more total deposition of organic pollutants despite its receiving less precipitation. Although PBDEs and emerging organic pollutants were detected, the bulk of the deposition consisted of PCBs and hexachlorocyclohexanes (HCHs) at both sites. Several NFRs were identified in indoor and ventilation air samples including TBECH, pentabromotoluene (PBT), hexabromobenzene (HBB), 1,2-bis(pentabromodiphenyl)ethane (DBDPE), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB), and bis(2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (TBPH). There was no significant difference between concentrations of contaminants in ventilation system air and indoor air indicating that the flame retardants included in this study reach the outdoor environment via ventilation systems. Dust and outdoor air samples have only been analyzed for HBCDDs so far. HBCDD concentrations in apartments, offices, and schools were lower than reported concentrations for other countries in similar microenvironments. However, an enrichment of α-HBCDD compared to γ-HBCDD was observed in dust taken from near treated products in stores when compared to dust taken directly from those products. Very low concentrations of HBCDDs were detected in outdoor air.

Arctic column ozone reached record low values (∼310 DU) during March of 2011, exposing Arctic ecosystems to enhanced UV-B. We identify the cause of this anomaly using the Oslo CTM2 atmospheric chemistry model driven by ECMWF meteorology to simulate Arctic ozone from 1998 through 2011. CTM2 successfully reproduces the variability in column ozone, from week to week, and from year to year, correctly identifying 2011 as an extreme anomaly over the period. By comparing parallel model simulations, one with all Arctic ozone chemistry turned off on January 1, we find that chemical ozone loss in 2011 is enhanced relative to previous years, but it accounted for only 23% of the anomaly. Weakened transport of ozone from middle latitudes, concurrent with an anomalously strong polar vortex, was the primary cause of the low ozone When the zonal winds relaxed in mid-March 2011, Arctic column ozone quickly recovered.

The occurrence, distribution, and temperature dependence in the marine atmosphere of several alternative brominated flame retardants (BFRs), Dechlorane Plus (DP) and polybrominated diphenyl ethers (PBDEs) were investigated during a sampling cruise from the East Indian Archipelago toward the Indian Ocean and further to the Southern Ocean. Elevated concentrations were observed over the East Indian Archipelago, especially of the non-PBDE BFR hexabromobenzene (HBB) with concentrations up to 26 pg m-3 which were found to be related to continental air masses from the East Indian Archipelago. Other alternative BFRs- pentabromotoulene (PBT), pentabromobenzene (PBBz), and 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE)-were elevated, too, with concentrations up to 2.8, 4.3, and 2.3 pg m-3, respectively. DP was detected from 0.26 to 11 pg m-3 and bis-(2-ethylhexyl)- tetrabromophthalate (TBPH) ranged from not detected (nd) to 2.8 pg m -3, respectively. PBDEs ranged from nd to 6.6 pg m-3 (∑10PBDEs) with the highest individual concentrations for BDE-209. The approach of Clausius-Clapeyron (CC) plots indicates that HBB is dominated by long-range atmospheric transport at lower temperatures over the Indian and Southern Ocean, while volatilization processes and additional atmospheric emissions dominate at higher temperatures. In contrast, BDE-28 and -47 are dominated by long-range transport without fresh emissions over the entire cruise transect and temperature range, indicating limited fresh emissions of the meanwhile classic PBDEs.

Two cases of free tropospheric aerosol layers observed with multi-wavelength Raman lidars over Évora (Portugal) and Granada (Spain) were investigated. Optical properties, both, columnar and vertically-resolved, of a forest fire smoke plume from North America on 13 June 2011, and of mineral dust layers on 27 June 2011 are presented. The aerosol optical depth and Ångström exponents derived from lidar data were compared to sun photometer measurements. The aerosol optical depth at 355 nm of the free tropospheric smoke layers were about 25 to 30% of the columnar aerosol optical depth found from sun photometer measurements at both sites. The lidar ratio at 355 nm was 46±14 sr and 48±16 sr, over Évora and Granada, espectively. The lidar ratio at 532 nm over Évora was 66±19 sr. The investigation of the dust plume showed larger differences in the aerosol optical properties observed at the two sites. This was due to different transportation paths and intrusion of other aerosol types, namely anthropogenic and marine aerosols., The authors want to acknowledge the Portuguese Foundation for Sciences and Technology FCT for grant SFRH/BD/47521/2008 and projects REDE/1527/RNG/ 2007 and PTDC/CTE-ATM/65307/2006. This work was partially funded by the Spanish Ministry of Science and Technology through projects CGL2010-18782, CSD2007-00067 and CGL2011-13580-E/CLI as well as by the EU through the ACTRIS project (EUINFRA-2010-1.1.16-262254).

This study presents a procedure to differentiate the local and remote sources of particulate-bound polycyclic aromatic hydrocarbons (PAHs).Data were collected during an extended PM(2.5) sampling campaign (2009-2010) carried out for 1 year in Venice-Mestre, Italy, at three stations with different emissive scenarios: urban, industrial, and semirural background. Diagnostic ratios and factor analysis were initially applied to point out the most probable sources. In a second step, the areal distribution of the identified sources was studied by applying the discriminant analysis on factor scores. Third, samples collected in days with similar atmospheric circulation patterns were grouped using a cluster analysis on wind data. Local contributions to PM(2.5) and PAHs were then assessed by interpreting cluster results with chemical data.Results evidenced that significantly lower levels of PM(2.5) and PAHs were found when faster winds changed air masses, whereas in presence of scarce ventilation, locally emitted pollutants were trapped and concentrations increased. This way, an estimation of pollutant loads due to local sources can be derived from data collected in days with similar wind patterns. Long-range contributions were detected by a cluster analysis on the air mass back-trajectories. Results revealed that PM(2.5) concentrations were relatively high when air masses had passed over the Po Valley. However, external sources do not significantly contribute to the PAHs load.The proposed procedure can be applied to other environments with minor modifications, and the obtained information can be useful to design local and national air pollution control strategies.

We present a comprehensive characterization of cloud condensation nuclei (CCN) sampled in the Alaskan Arctic during the 2008 Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC) project, a component of the POLARCAT and International Polar Year (IPY) initiatives. Four distinct air mass types were sampled including relatively pristine Arctic background conditions as well as biomass burning and anthropogenic pollution plumes. Despite differences in chemical composition, inferred aerosol hygroscopicities were fairly invariant and ranged from κ = 0.1–0.3 over the atmospherically-relevant range of water vapor supersaturations studied. Analysis of the individual mass spectral m/z 43 and 44 peaks from an aerosol mass spectrometer show the organic aerosols sampled to be well-oxygenated, consistent with with long-range transport and aerosol aging processes. However, inferred hygroscopicities are less than would be predicted based on previous parameterizations of biogenic oxygenated organic aerosol, suggesting an upper limit on organic aerosol hygroscopicity above which κ is less sensitive to the O:C ratio. Most Arctic aerosol act as CCN above 0.1 % supersaturation, although the data suggest the presence of an externally-mixed, non-CCN-active mode comprising approximately 0–20 % of the aerosol number. CCN closure was assessed using measured size distributions, bulk chemical composition measurements, and assumed aerosol mixing states; CCN predictions tended toward overprediction, with the best agreement (± 0–20 %) obtained by assuming the aerosol to be externally-mixed with soluble organics. Closure also varied with CCN concentration, and the best agreement was found for CCN concentrations above 100 cm−3 with a 1.5- to 3-fold overprediction at lower concentrations.

24 páginas, 3 tablas, 4 figuras., The present study shows the occurrence of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209) in microbial biofilms of Pyrenean and Tatra high mountain lakes despite its low vapor pressure and high hydrophobicity. Aerosol air transport is therefore a feasible mechanism for BDE-209 accumulation in sites up to 2688 m above sea level. This compound and other PBDEs exhibit altitudinally-dependent distribution involving higher concentrations with increasing mountain lake elevation. However, the apparently very high enthalpies of the concentration gradients observed, including BDE-209, suggest that bacterial anaerobic debromination also plays a significant role in the resulting altitudinal distributions. This microbial mechanism explains the relative abundances of PBDEs and their within lake differences between rocky and sediment microbial biofilms, thereby showing that the altitudinal pattern observed is not purely due to water temperature control on bacterial activity but also to changes in the availability of anaerobic microenvironments which increase with increasing lake productivity at lower altitudes. Capsule: Decabromodiphenyl ether and the other polybromodiphenyl congeners show vertical distributions in high mountains due to temperature effects and microbial degradation., This work has been supported by the EU Projects Euro-Limpacs (GOCE-CT-2003- 505540) and ArcRisk (FP7-ENV-2008-1-226534), Spanish MEC project Trazas (CGL2004-02989) and Consolider Ingenio “GRACCIE” program (CSD2007-00067). Technical assistance in instrumental analysis by R. Chaler, D. Fanjul, and R. Mas, analytical advice by J. López and P. Fernández, field help by L. Camarero, M. Bacardit, G. Mendoza, E. Gallego, and S. Jarque is acknowledged. One of the authors, M.B., thanks a FPU grant of the Spanish Ministry of Education and Science.

Secondary inorganic aerosol, most notably ammonium nitrate and ammonium sulphate, is an important contributor to ambient particulate mass and provides a means for long range transport of acidifying components. The modelling of the formation and fate of these components is challenging. Especially, the formation of the semi-volatile ammonium nitrate is strongly dependent on ambient conditions and the precursor concentrations. For the first time an hourly artefact free data set from the MARGA instrument is available for the period of a full year (1 August 2007 to 1 August 2008) at Cabauw, the Netherlands. This data set is used to verify the results of the LOTOS-EUROS model. The comparison showed that the model underestimates the SIA levels. Closer inspection revealed that base line values appear well estimated for ammonium and sulphate and that the underestimation predominantly takes place at the peak concentrations. For nitrate the variability towards high concentrations is much better captured, however, a systematic relative underestimation was found. The model is able to reproduce many features of the intra-day variability observed for SIA. Although the model captures the seasonal and average diurnal variation of the SIA components, the modelled variability for the nitrate precursor gas nitric acid is much too large. It was found that the thermodynamic equilibrium module produces a too stable ammonium nitrate in winter and during night time in summer, whereas during the daytime in summer it is too unstable. We recommend to improve the model by verification of the equilibrium module, inclusion of coarse mode nitrate and to address the processes concerning SIA formation combined with a detailed analysis of the data set at hand. The benefit of the hourly data with both particulate and gas phase concentrations is illustrated and a continuation of these measurements may prove to be very useful in future model evaluation and improvement studies. Based on our findings we propose to implement a monitoring strategy using three levels of detail within the Netherlands.

During the POLARCAT summer campaign in 2008, two episodes (2g-5 July and 7g-10 July 2008) occurred where low-pressure systems traveled from Siberia across the Arctic Ocean towards the North Pole. The two cyclones had extensive smoke plumes from Siberian forest fires and anthropogenic sources in East Asia embedded in their associated air masses, creating an excellent opportunity to use satellite and aircraft observations to validate the performance of atmospheric transport models in the Arctic, which is a challenging model domain due to numerical and other complications. Here we compare transport simulations of carbon monoxide (CO) from the Lagrangian transport model FLEXPART and the Eulerian chemical transport model TOMCAT with retrievals of total column CO from the IASI passive infrared sensor onboard the MetOp-A satellite. The main aspect of the comparison is how realistic horizontal and vertical structures are represented in the model simulations. Analysis of CALIPSO lidar curtains and in situ aircraft measurements provide further independent reference points to assess how reliable the model simulations are and what the main limitations are. The horizontal structure of mid-latitude pollution plumes agrees well between the IASI total column CO and the model simulations. However, finer-scale structures are too quickly diffused in the Eulerian model. Applying the IASI averaging kernels to the model data is essential for a meaningful comparison. Using aircraft data as a reference suggests that the satellite data are biased high, while TOMCAT is biased low. FLEXPART fits the aircraft data rather well, but due to added background concentrations the simulation is not independent from observations. The multi-data, multi-model approach allows separating the influences of meteorological fields, model realisation, and grid type on the plume structure. In addition to the very good agreement between simulated and observed total column CO fields, the results also highlight the difficulty to identify a data set that most realistically represents the actual pollution state of the Arctic atmosphere. © 2011 Adis Data Information BV. All rights reserved., SCOPUS: ar.j, info:eu-repo/semantics/published

5 p.; International audience; The eruption of the Eyjafjallajökull in April 2010 led to the injection in the troposphere of an important quantity of volcanic ash whose advection towards densely populated areas raised serious concerns regarding potential impacts on air quality. Here we investigate to what extent air quality in France was altered using exclusively quantitative data that was available in near real-time. We rely on a combination of atmospheric dispersion modelling, ground-based remote sensing, and chemical characterization of airborne particles. One week after the onset of the eruption we were able to conclude that the Eyjafjallajökull ash plume was locally responsible for an increase of up to 30 +/- 10 µgm-3 of total PM10 (particulate matter finer than 10 µm) that reached 65 mg m-3 on 18 and 19 April 2010. The methodology presented in this letter offers promising perspectives in terms of emergency response strategy when facing such unforeseen atmospheric dispersion events.

Secondary inorganic aerosol, most notably ammonium nitrate and ammonium sulphate, is an important contributor to ambient particulate mass and provides a means for long range transport of acidifying components. The modelling of the formation and fate of these components is challenging. Especially, the formation of the semi-volatile ammonium nitrate is strongly dependent on ambient conditions and the precursor concentrations. For the first time an hourly artefact free data set from the MARGA instrument is available for the period of a full year (1 August 2007 to 1 August 2008) at Cabauw, the Netherlands. This data set is used to verify the results of the LOTOS-EUROS model. The comparison showed that the model underestimates the SIA levels. Closer inspection revealed that base line values appear well estimated for ammonium and sulphate and that the underestimation predominantly takes place at the peak concentrations. For nitrate the variability towards high concentrations is much better captured, however, a systematic relative underestimation was found. The model is able to reproduce many features of the intra-day variability observed for SIA. Although the model captures the seasonal and average diurnal variation of the SIA components, the modelled variability for the nitrate precursor gas nitric acid is much too large. It was found that the thermodynamic equilibrium module produces a too stable ammonium nitrate in winter and during night time in summer, whereas during the daytime in summer it is too unstable. We recommend to improve the model by verification of the equilibrium module, inclusion of coarse mode nitrate and to address the processes concerning SIA formation combined with a detailed analysis of the data set at hand. The benefit of the hourly data with both particulate and gas phase concentrations is illustrated and a continuation of these measurements may prove to be very useful in future model evaluation and improvement studies. Based on our findings we propose to implement a monitoring strategy using three levels of detail within the Netherlands.

The environmental occurrence and behaviour of the brominated flame retardant (BFR) decabromodiphenyl ethane (dbdpe) has only been studied to a limited extent. It is structurally similar to decabromodiphenyl ether (decaBDE), which makes it conceivable that dbdpe may also become an environmental contaminant of concern. A method for environmental analysis and comparative assessments of dbdpe and decaBDE was developed. Both BFRs were studied in: a mass balance of the Henriksdal WWTP in Stockholm (Paper I); an international survey of sewage sludge (Paper II); sediment along a transect from Henriksdal WWTP to the outer archipelago of Stockholm and from isolated Swedish lakes (Paper III); and a benthic food web from the Scheldt estuary (Paper IV). Dbdpe was found in sludge from every country surveyed, indicating that it may be a worldwide concern. The WWTP mass balance showed that virtually all of the BFRs were transferred from wastewater to sludge. A small fraction was emitted via the effluent, confirming emissions to the aquatic environment. In the marine sediment, the BFR levels close to the WWTP outfall were high. They decreased along the transect to low levels in the outer archipelago. The study of lake sediment showed a widespread presence of dbdpe in the Swedish environment and provided evidence that it originates from long range atmospheric transport. In the food web, dbdpe did bioaccumulate to a small extent which was similar to decaBDE. The transfer of the BFRs from sediment to benthic invertebrates was low, while transfer from prey to predator was higher. Biodilution was observed rather than biomagnification. This work suggests that the persistence, the susceptibility to long range atmospheric transport, and the potential for bioaccumulation are similar for dbdpe and the regulated decaBDE that it is replacing. Thus, there is a risk that a problematic environmental pollutant is being replaced with a chemical that is equally problematic. At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 4: Manuscript.

International audience; This paper presents results from a new method, ZooM-CiTTy, that aims to accurately reproduce filamentation observed in profiles of chemically active species in the free troposphere. Lagrangian tracer reconstructions of aircraft measurements across pollutant plumes including a stochastic representation of mixing are coupled with photochemical trajectory simulations, initialized with global model fields. The results provide a high-resolution simulation of trace gases along the flight track together with a detailed picture about the multiple air mass origins influencing chemical composition in the region where plume measurements were taken. This paper builds on results from Pisso et al. (2009) for the dynamic part of the model (the stochastic tracer reconstructions) and focuses on reconstruction of reactive species like O3. The model is evaluated for a case of long-range transport of a forest fire plume from Alaska to Europe. Simulated trace species are compared with measurements made in the plume by the DLR Falcon aircraft flying over Europe, and the role of photochemistry in governing the chemical composition across the plume is evaluated. It is shown that the model reproduces well O3 and NOy concentrations and O3 production per CO in the plumes as well as gradients at plume edges. In particular, because ZooM-CiTTy represents the contribution of several air masses to a measurement at a particular location, the model can reproduce so-called mixing lines between air masses. Results show that photochemistry and mixing contributions vary in different parts of the plume and that resulting trace gas correlations are a combination of these different mixtures. One limitation of the method is the fact that mixing between air masses is only performed at the end of the trajectories. Errors on simulated O3 reconstruction from this formulation are evaluated. These errors seems to be negligible in this case (in the free troposphere, far from emission region) because strong gradients are maintained by large-scale winds. Results from ZooM-CiTTy are also used to evaluate errors due to nonlinearities in O3 photochemistry in coarse-grid models. It is shown that in cases where strong gradients are maintained, errors in net O3 production can be as high as 50% at plumes edges. This new method is interesting to simulate relatively small layering structures observed in the free troposphere, but a more realistic treatment of mixing “en route” is needed if the model has to be used more extensively.

This thesis deals with the vertical variability of tropospheric ozone and aerosols in the Mediterranean region, more precisely on the transport processes that govern this variability and the radiative impacts of biomass burning aerosols. The analysis of STAAARTE Hellen 96 campaign, first airborne campaign above Greece, permitted to understand that the ozone variability in the area is governed mainly by long range transport (western Europe, northern Africa, upper troposphere) and secondly by local emissions. Afterwards, the analysis of Pic 2005 campaign, realised on French Pyrenean, permitted to discuss the representativity of ozone at the level of Pic du Midi high altitude station and more precisely to estimate the influence of air masses originating from the rural boundary layer and arriving at Pic du Midi due to summer mountain breezes. On the timescale of some hours, we usually observe a difference of about 10 ppb between the ozone's measurements at Pic du Midi and the free troposphere during summer, which can be explained by transport from the boundary layer and the mixing of these air masses with free troposphere during their vertical displacement. This leads to an influence of the Pic du Midi measurements from the boundary layer by about 20-50%. Lastly, we estimated the radiative impact of biomass burning aerosols layers using either the measurements of a campaign for the study of international pollution transport (ITOP 2004) or the successive observations realised by CALIPSO of the fires at the south Greece on August 2007., Dans le cadre de cette thèse, je me suis intéressé à la variabilité de l'ozone et des aérosols troposphériques en région méditerranéenne, plus précisément aux processus de transport qui pilotent cette variabilité et aux impacts radiatifs des aérosols des feux de biomasse. L'analyse de la campagne STAAARTE Hellen 96, première campagne aéroportée en Grèce, a permis d'établir que la variabilité de l'ozone dans cette région est pilotée en premier lieu par le transport à longue distance (Europe occidentale, Afrique du nord et haute troposphère), puis modulée par les émissions locales. Ensuite, l'analyse de la campagne Pic 2005, effectuée dans les Pyrénées françaises, a permis de discuter la représentativité de l'ozone au niveau de la station d'haute altitude du Pic du Midi, plus précisément d'estimer l'influence exercée par l'apport de masses d'air issues de la couche limite rurale par les brises orographiques estivales qui se développent dans la journée. A l'échelle de quelques heures, on observe souvent en été des écarts de l'ordre de 10 ppb entre l'ozone mesuré au Pic du Midi et la troposphère libre, écarts qui s'expliquent par le transport depuis la couche limite et le mélange de ces masses d'air avec la troposphère libre. La mesure en altitude au niveau du Pic du Midi est alors influencée à hauteur de 20 à 50% par la couche limite. Enfin, on a cherché à estimer l'impact radiatif des couches d'aérosols des feux de biomasse en utilisant d'une part les mesures d'une campagne d'étude du transport intercontinental de la pollution (ITOP 2004), d'autre part les observations successives effectuées par CALIPSO des incendies au sud de la Grèce en août 2007.

The work presented here intends to characterize the variations of atmospheric concentrations of CO2, CO, O3 and ultrafine particles, over a large scale aircraft transect above Siberia, during three intensive YAK-AEROSIB campaigns in April 2006, September 2006 and August 2007, respectively. Pollutant and greenhouse gases distribution in this poorly studied region is needed to model atmospheric long range transport. I show here that CO concentrations at the time of the campaigns is broadly affected by (1) advection of Chinese pollutants through baroclinic perturbations, (2) advection (diffuse or not) of European pollutants at various altitudes, (3) and of biomass burning from Central Asia. This set of factors is analyzed through a novel statistical technique based on clustering of backward transport simulated by the FLEXPART Lagrangian model. Large observed CO2 gradients in summer are matched against vertical mixing in GCM simulated CO2. At last I present ultrafine particle measurements, and a possible nucleation summer maximum in the clean, continental mid-troposphere.; Cette thèse a pour objectif de caractériser et d'analyser les variations de concentration atmosphérique en CO2, CO et O3 et en aérosols ultrafins mesurées au dessus de la Sibérie, lors de trois campagnes intensives aéroportées en avril et septembre 2006 et en août 2007. La Sibérie est éloignée des grandes sources de pollution de l'hémisphère nord. La distribution, mal connue, de polluants et de gaz à effet de serre dans cette région est cruciale pour la modélisation du transport à grande échelle des polluants. Les mesures ont permis de mettre en évidence l'impact de (1) l'advection de polluants chinois dans des perturbations baroclines, (2) l'advection de polluants européens à diverses altitudes, (3) des feux de biomasse en Asie Centrale, à travers une nouvelle technique (clustering de fonction d'influence lagrangiennes). Les gradients estivaux importants de CO2 sont utilisés pour contraindre le mélange vertical du modèle de circulation globale. Un possible maximum de nucléation dans la moyenne troposphère continentale propre en été est mis en évidence à partir de mesures de particules ultrafines.

We investigated an unusual elevated-ozone episode that took place at a high altitude measuring site Zavižan (44.817°N, 14.983°E, 1594 m a.s.l.). The episode was characterized by three consecutive peaks. The first one was the highest (over 120 ppbv), and it occurred at the late night on 17 July. Following two (both about 110 ppbv) appeared approximately 18 and 36 hours after the first peak, respectively. The night-time maximum and the departure from the usual diurnal variation of ozone concentration during investigated episode point to the non-local pollution sources, rather than to local photochemical production. Thus, recorded ozone peaks might arise due to the long-range transport of photo-oxidants ; 2) stratospheric ozone intrusion ; or 3) they might be result of both (1) and (2). In order to inspect which of above processes is responsible for the increased ozone concentrations we applied the unified EMEP model, which among others, simulates atmospheric transport and deposition of photo-oxidants, and, a mesoscale numerical weather prediction model WRF-ARW V2.2. Additionally, the larger scale atmospheric conditions were examined based on the ECMWF ERA-40 reanalysis fields. Results suggest that the stratospheric ozone intrusion played an important role in the occurrence of investigated episode.

The present study analyzes PM10 concentration data collected by the Greek air quality monitoring network at 8 sites over the Greater Athens Area, for the period of 2001-2004. The primary objectives were to assess the degree of compliance with the EU-Iegislated air quality standard for PM10 and also provide an overall statistical examination of the factors controlling the seasonal and spatial variation of concentrations, over the wider urban agglomeration. Daily concentrations, averaged over the whole study period, ranged between 32.3 and 60.9 mu g in(-3). The four-year average concentration of PM10 at five sites exceeded the annual limit value of 40 mu g in(-3), while most of the sites surpassed the allowed percentage of exceedances of the daily limit value (50 mu g m(-3)), for each of the four years. The seasonal variation of PM10 levels was not found to be uniform across the eight sites, with average cold-period concentrations being higher at four of them and warm period concentrations being significantly higher at three sites, which also displayed recurring annual variation of monthly concentrations. Concentration levels displayed moderate spatial heterogeneity. Nevertheless significant inter-site correlations were observed (ranging between 0.55 and 085). The determination of the spatial correlation levels relied mainly on site types rather than on inter-site distances. Monitoring sites were classified accordingly using cluster analysis in two groups presenting distinct spatiotemporal variation and affected by different particle formation processes. The group including urban sites was mainly affected by primary, combustion-related processes and especially vehicular traffic, as it was also deduced through the examination of the diurnal distribution of particulate levels and through factor analysis. On the contrary, suburban background sites seemed more affected by particle transport from more polluted neighboring areas and secondary particle formation through gaseous precursors, both processes aided from favoring meteorological conditions. The association of the PM10 levels with backwards trajectories was also examined, in an attempt to account for the possible long range transport of particles in Athens. It was found that a notable part of area-wide episodic events could be attributed to trans-boundary transport of particles, with the origins of some severe dust outbreaks traced back to the Sahara desert and the Western Mediterranean. (C) 2007 Elsevier B.V. All rights reserved. Science of the Total Environment

We investigated an unusual elevated-ozone episode that took place at a high altitude measuring site Zavižan (44.817°N, 14.983°E, 1594 m a.s.l.). The episode was characterized by three consecutive peaks. The first one was the highest (over 120 ppbv), and it occurred at the late night on 17 July. Following two (both about 110 ppbv) appeared approximately 18 and 36 hours after the first peak, respectively. The night-time maximum and the departure from the usual diurnal variation of ozone concentration during investigated episode point to the non-local pollution sources, rather than to local photochemical production. Thus, recorded ozone peaks might arise due to the long-range transport of photo-oxidants; 2) stratospheric ozone intrusion; or 3) they might be result of both (1) and (2). In order to inspect which of above processes is responsible for the increased ozone concentrations we applied the unified EMEP model, which among others, simulates atmospheric transport and deposition of photo-oxidants, and, a mesoscale numerical weather prediction model WRF-ARW V2.2. Additionally, the larger scale atmospheric conditions were examined based on the ECMWF ERA-40 reanalysis fields. Results suggest that the stratospheric ozone intrusion played an important role in the occurrence of investigated episode.

This study of inputs of trace metal elements (TME) in the Aspe valley (Pyrénées Atlantiques) has two objectives: (1) to define a reference state of metallic contaminants for the monitoring of road traffic emissions since the opening of the Somport tunnel and, (2) to evaluate sources and climatic conditions which contribute to TME inputs in the Aspe valley. To establish air quality indicators, TME (Al, Na, Mg, K, V, Mn, Cr, Zn, Cu, Rb, Cd, Sn, Sb, Ba, Ce, Pb and U) and lead isotopic ratios (208Pb/206Pb, 206Pb/207Pb and 208Pb/207Pb) were determined in the atmospheric receptors (fresh snow, wet deposition, atmospheric particulates and lichen). Sampling and analyses with ultra clean procedures were employed for TME quantification. Variability of atmospheric receptors studied, allows integration on a daily and pluriannual temporal scale and a spatial scale in the North-South axis of the valley and as a function of the altitude from the road. The Aspe valley presents a level of contamination characteristic of remote European areas and the metallic contaminants identified are Cd, Sb, Zn, Cu, Pb and Sn. In the low valley, air quality indicators indicate contaminant contributions (i) from local emissions of domestic heat sources, from agricultural burning practices and road traffic, and (ii) from regional anthropogenic sources of waste incinerators, metallurgic industries and urban centres. In altitude, the valley is significantly influenced by wind erosion and long range transport of TME in the Northern Hemisphere. Characterisation of TME and the isotopic ratios of Pb in the Somport tunnel indicate (i) a significant emission of Cu, Sb, Zn and Ba and (ii) an isotopic composition from a slightly radiogenic source even though Pb concentrations indicate low emissions from road traffic emissions. Nevertheless, the low traffic volume in the Aspe valley prevents conclusive evidence of significant contamination from road traffic.; L'étude des apports atmosphériques des éléments traces métalliques (ETM) dans la vallée d'Aspe (Pyrénées Atlantiques) a un double objectif : (1) établir un état de référence des contaminants métalliques pour le suivi des émissions du trafic routier liés à l'ouverture du tunnel du Somport et, (2) évaluer les sources et les conditions climatologiques qui contribuent aux apports des ETM dans la vallée d'Aspe. La détermination des ETM (Al, Na, Mg, K, V, Mn, Cr, Zn, Cu, Rb, Cd, Sn, Sb, Ba, Ce, Pb et U) et des rapports isotopiques du plomb (208Pb/206Pb, 206Pb/207Pb et 208Pb/207Pb) dans les récepteurs atmosphériques (neiges fraîches, dépôts humides, particules atmosphériques et lichens) a permis de mettre en place des indicateurs de la qualité de l'air. La quantification des ETM a nécessité la mise en oeuvre de protocoles de prélèvements et d'analyses ultra-traces. Les différents récepteurs atmosphériques étudiés permettent d'intégrer une échelle temporelle journalière à pluriannuelle et un gradient spatial dans l'axe Nord-sud de la vallée et en fonction de l'altitude.La vallée d'Aspe présente un niveau de contamination spécifique des zones éloignées des émissions anthropiques et les contaminants métalliques identifiés sont le Cd, Sb, Zn, Cu, Pb et Sn. Dans sa partie basse, les indicateurs de la qualité de l'air présentent une contribution des contaminants (i) liée aux émissions locales des combustions domestiques, à la pratique saisonnière de l'écobuage et au trafic routier, et (ii) aux sources anthropiques régionales de l'incinération des déchets ménagers, de l'industries métallurgique et des centres urbains. Dans sa partie haute, la vallée est soumise significativement, d'une part, à l'érosion éolienne et, d'autre part, à la contribution des sources du transport à grande échelle de l'hémisphère Nord. La caractérisation des ETM et des rapports isotopiques du plomb dans le tunnel du Somport indique (i) que le trafic routier émet significativement du Cu, Sb, Zn et Ba et (ii) bien que Pb présente de faibles émissions sa composition isotopique montre une source faiblement radiogénique du trafic routier. Toutefois, la faible circulation des véhicules dans la vallée d'Aspe ne permet pas de mettre évidence une contamination significative provenant des émissions du trafic routier.

International audience; We propose a multimedia model-based methodology to evaluate whether a chemical substance qualifies as POP-like based on overall persistence (Pot,) 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 P,), 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 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.

The ITCT-Lagrangian-2K4 (Intercontinental Transport and Chemical Transformation) experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of air masses in the free troposphere away from emissions. To this end, attempts were made to intercept and sample air masses several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts from two Lagrangian models that were used to direct the aircraft into target air masses. A novel technique then identifies Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole air samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these "coincident matches'' is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown, and the downwind minus upwind differences in tracers are discussed.

Retrievals of trace gas columns from the measurements of backscattered radiation by GOME (Global Ozone Monitoring Experiment) show that enhanced tropospheric columns of ozone (O3), nitrogen dioxide (NO2) and formaldehyde (HCHO), over the African continent occur frequently. This study focuses on the behaviour of trace gases over Africa in September 1997, a period impacted by the strongest known El Nino phase of the ENSO. It investigates our qualitative and quantitative understanding of the retrieved tropospheric trace gas column densities. The emissions of NOx and volatile organic compounds (VOC) from biomass burning, biogenic sources and lightning and their photochemical transformation have been investigated. By performing a trajectory analysis, the transport of air masses from the different emission regions was analysed and the potential atmospheric spatial distribution determined. BRemen’s Atmospheric PHOtochemical model (BRAPHO) was applied to compute the chemistry along a large number of trajectories. From these results, tropospheric column amounts of O3, NO2 and HCHO were derived. Tropospheric trace gas columns retrieved from GOME measurements and those calculated are in reasonable agreement. Their general spatial extent was similar in the lower troposphere but the modeled trace gas columns in the upper troposphere were located south of the retrieved columns. We attribute this behaviour to uncertainties in the ERA-40 meteorological data in the upper troposphere. The significance of biomass burning and of biogenic emissions with respect to HCHO columns over Africa was investigated. The analysis reveals that the total amounts of HCHO generated over Africa during September 1997 as a result of biomass burning and biogenic emissions are similar. However the HCHO from biogenic sources has the highest specific columns and these are located close to their source. In comparison the HCHO from biomass burning is predicted to be produced and transported over a much wider area. Overall all the emission processes mix together to produce the plume of O3.

14 pages, 6 figures.-- PMID: 15840533 [PubMed].-- Printed version published Jul 2005., Semi-volatile organochlorine compounds (OC) were analyzed in remote Andean soils and lake sediments. The sampling sites covered a wide latitudinal gradient from 18°S to 46°S along Chile and an altitudinal gradient (10–4500 m). The concentrations were in the order of background levels, involving absence of major pollution sources in the high mountain areas. Significant correlations were found between log-transformed concentrations of hexachlorobenzene, α- and γ-hexachlorocyclohexane in soils and total organic content (TOC). In addition, TOC-normalized concentrations of the most volatile OC showed a significant linear dependence with air temperature. This good agreement points to temperature as a significant factor for the retention of long range transported OC in remote ecosystems such as the Andean mountains, although other variables should not be totally excluded. The highest concentrations of OCs were achieved in the sites located at highest altitude and lowest temperature of the dataset., Distribution of persistent organochlorine compounds in the Andean Mountain lakes is influenced by temperature., This work was supported by FONDECYT No. 1010640 and the EU funded project GLOBAL-SOC (ENV4-CT97-0503).

Changes in the lead concentration in Antarctic snow over the past 30 years are considered as a response of the environment to a well-documented environmental change (decrease of lead emissions into the atmosphere). New data confirm the recent decreasing trend of lead concentration in snow as revealed by previous studies. Furthermore, comparing changes in the lead concentration in Antarctic snow layers with lead emissions from different anthropic sources, we can hypothesise that under present-day climatic conditions, lead-enriched aerosols reaching the Atlantic and Pacific sectors of East Antarctica originate mainly in South America and Australia, respectively.

Aerosol particle size distributions were measured on the Swedish island Ostergamsholm, about

Atmospheric change comprises many phenomena, namely climate change, acidic deposition, stratospheric ozone depletion, SMOG, increasing trend of suspended particulate matter, and hazardous air pollutants (HAPs). Among HAPs, a particular group of Persistent Organic Pollutants (POPs), such as some organochlorine pesticides, has shown a variety of toxic effects, altering the biodiversity of many ecosystems. Because of their persistence in the environment, and of their long range transport, the study of the global cycle of POPs is important in understanding how they can affect biodiversity. This can be accomplished by coupling different approaches: toxicity and ecological studies, emission estimates, and the use of global models.

Aerosol particle size distributions were measured on the Swedish island Ostergamsholm, about

資料番号: AA0063353013

The European carbon monoxide (CO) budget is studied in relation to the synoptic circulation throughout 2001, using the nested-grid configuration of the GEOS-CHEM global model and CO measurements from 31 rural background stations. To meet the aims of this study, a seasonal circulation type (CT) classification is developed for the Northern Hemisphere based on mean sea-level pressure (SLP) fields, as well as two upper atmospheric levels, over a 60-yr period. The highest contribution to the European surface CO concentrations is attributed to regional anthropogenic sources (up to ~80%), which become more important under the prevalence of anticyclonic circulation conditions. The corresponding contribution of the long-range transport (LRT) from North America (up to 18%) and Asia (up to 20%) is found highest (lowest) in winter and spring (summer and autumn). The transport of the CO towards Europe in winter is more intense under cyclonic circulation, while both cyclonic and anticyclonic patterns favour LRT during other seasons. Occasionally (mainly in winter and spring), LRT contribution is higher than the regional one (up to 45%). In the free troposphere, the LRT contribution increases, with the largest impact originating from Asia. This flow is favoured by the intense easterly circulation in summer, contributing up to 30% in the Eastern Mediterranean during this season. On the other hand, the regional contribution in the upper levels decreases to 22%. The contribution of CO chemical production is significant for the European CO budget at all levels and seasons, exceeding 50% in the free troposphere during summer. Keywords: Europe, atmospheric circulation, carbon monoxide, long-range transport, global model (Published: 25 April 2013) Citation: Tellus B 2013, 65 , 18640, http://dx.doi.org/10.3402/tellusb.v65i0.18640 To access the supplementary material to this article, please see Supplementary files under Article Tools.

MATCH-Västkusten is a dispersion model for the three counties of Göteborg-Bohus, Hallandand Älvsborg on the Swedish west-coast. MATCH stands for "Mesoscale Atmospheric Transportand CHemistry model" and is an Eulerian atmospheric dispersion model, including physicaland chemical processes goveming sources, atmospheric transport and sinks of oxidizedsulphur and oxidized and reduced nitrogen.U sing the MATCH-Västkusten system, air pollution contributions from diff erent source typeslike traffic, industry, shipping, farming etc. can be obtained. Using a combination of air andprecipitation chemistry measurements and the MATCH-Västkusten model, also the contributionof air pollution and deposition from long range transport can be quantified in the model region.In the report, many results from the air pollution assessment studies for the year 1991 arepresented. As examples of result can be mentioned that the sources within the west-coastregion account for a substantial fraction of the total NO2-concentration, while the deposition ofsulphur and nitrogen is dominated by the long range transport. Detailed values of the differentcontributions are given in the report. MATCH-Västkusten är en regional spridningsmodell för Göteborgs och Bohus, Hallands och Älvsborgs län. Modellen, som utvecklats av SMHI på uppdrag av länsstyrelserna i de tre västkustlänen, skall vara ett redskap i det framtida regionala luftmiljöarbetet. MATCH, som står för "Mesoscale Atmospheric Transport and CHemistry model", är ett system för regional spridningsmodellering, som kan tillämpas för olika områden och med varierande geografisk upplösning. I det här fallet har en detaljerad anpassning av MATCH-systemet gjorts till västkustregionen. Med hjälp av modellen kan beräkningar göras av tex svavel- och kvävenedfallet inom olika delar av regionen, och detta kan sedan sättas i relation till kritiska belastningsgränser för hur mycket naturen tål. Därmed fås ett bra underlag för planering av nödvändiga åtgärder, som att införa utsläppsbegränsningar eller bestämma kalkningsbehov för skogar eller vattendrag. Andra frågor, som skall kunna besvaras, är t ex: Hur stor del av föroreningarna kommer från utlandet? Hur mycket bidrar den egna industrin med? Ger den tunga trafiken större bidrag än jordbruket? Vilka effekter får olika samhällsbeslut på luftmiljön - nu och i framtiden? I modellen görs beräkningar av spridning, torrdeposition, våtdeposition och kemiska reaktioner mellan följande kemiska föreningar: svaveldioxid (S02), ammoniumsulfat ((NH4) 2S04 och NH4HS04), övriga sulfatpartiklar (SO42-) kväveoxid (NO), kvävedioxid (N02), ammoniumnitrat (NH4N03), andra nitratpartiklar (NQ3·), salpetersyra (HN03) och ammoniak (NH3). En lokal anpassning av 03-halten inom modellområdet görs också. Emissionsdata, som utnyttjats vid beräkningarna, har tagits fram genom ett samarbete mellan myndigheter inom de tre länen. Den databashanterare, som utnyttjats, har utvecklats av lndic AB. De meteorologiska analyser, som ligger till grund för spridningsberäkningama, bygger på data från ett stort antal meteorologiska stationer och mätmaster. De erhållna analyserna utnyttjas därefter till att driva själva spridningsmodellen, varvid simuleringar av koncentration i luft och deposition i mark, vatten och vegetation av föroreningar emitterade inom de tre västkustlänen kan erhållas. Med hjälp av modellberäkningarna, som kombineras med mätdata från sex stycken bakgrundsstationer för föroreningsmätningar i luft och nederbörd, kan även den långväga föroreningstransporten från källor utanför Sverige kvantifieras inom olika delar av modellområdet. Metodiken innebär, att den höga upplösningen i MATCH-Västkusten ger en geografiskt mycket mer detaljerad tolkning av den långväga förorenings transportens betydelse, än vad direkta beräkningar på europaskala kan ge. De föroreningsstationer, som utnyttjas, drivs av Institutet för Vatten- och Luftvårdsforskning (IVL), Norsk lnstitutt for Luftforskning (NILU) och Statens Lantbruksuniversitet (SLU). MATCH-Västkusten har hittills utnyttjats för en luftmiljöanalys för år 1991. Koncentrationer i luft och deposition till mark, vegetation och vatten har beräknats för oxiderade svavelföreningar, oxiderade och reducerade kväveföreningar och kolväten. Långtransportens betydelse, betydelsen av de tre västkustlänens egna utsläpp samt betydelsen av delbidrag från olika källtyper inom länen har beräknats. Följande delbidrag har hittills studerats: tung trafik, personbilstrafik, tung trafik Göteborg, personbilstrafik Göteborg, industri, energiproduktion, sjöfart, jordbruk, skogsbruk, arbetsfordon, Göteborg totalt, Stenungsund totalt, Scanraff totalt och hushåll. I talet med att emissionsdata förnyas eller att olika framtidsscenarier skall studeras kan givetvis nya beräkningar göras. Några exempel på resultat: Av miljöanalysen för år 1991 framgår att NOP-länens bidrag till SO2-, NO2- och NH3-halten i luft är av ungefär lika stor betydelse som den långväga transportens bidrag, även om den geografiska fördelningen givetvis varierar. För depositionen är däremot långtransportbidragen helt dominerande. Den totala årliga svaveldepositionen är i södra delen av modellområdet ca 1 500 mg S/m2 och i den norra delen ca 800 mg S/m2, NOP-bidraget utgör endast ca 5 %. Depositionen av oxiderat kväve är i de södra delarna ca 1 000 mg N/m2 och i de norra delarna ca 550 mg N/m2 med ett bidrag från NOP-länens källor i storleksordningen 10%. För deposition av reducerat kväve har NOP-länens egna källor något större betydelse, ca 20%, och totalvärdena är ca 900 mg N/m2 i södra och ca 370 mg N/m2 i norra delen av modellområdet. Samtliga resultat avseende dygnsvärden, månadsvärden och årsvärden från luftmiljöstudien för 1991 finns tillgängliga på arbetsstationer, som finns hos uppdragsgivarna, för vidare bearbetning och presentation. I samband med beräkningarna har ett omfattande arbete lagts ner på att verifiera modellresultaten mot uppmätta halter och kvalitetssäkra det framtagna materialet

Tropical aerosol (PM10) samples (n = 49) collected from southeast coast of India were studied for water-soluble dicarboxylic acids (C2-C12), ketocarboxylic acids (C2-C 9), and -dicarbonyls (glyoxal and methylglyoxal), together with analyses of total carbon (TC) and water-soluble organic carbon (WSOC). Their distributions were characterized by a predominance of oxalic acid followed by terephthalic (t-Ph), malonic, and succinic acids. Total concentrations of diacids (227-1030 ng m-3), ketoacids (16-105 ng m-3), and dicarbonyls (4-23 ng m-3) are comparative to those from other Asian megacities such as Tokyo and Hong Kong. t-Ph acid was found as the second most abundant diacid in the Chennai aerosols. This feature has not been reported previously in atmospheric aerosols. t-Ph acid is most likely derived from the field burning of plastics. Water-soluble diacids were found to contribute 0.4%-3% of TC and 4%-11% of WSOC. Based on molecular distributions and backward air mass trajectories, we found that diacids and related compounds in coastal South Indian aerosols are influenced by South Asian and Indian Ocean monsoons. Organic aerosols are also suggested to be significantly transported long distances from North India and the Middle East in early winter and from Southeast Asia in late winter, but some originate from photochemical reactions over the Bay of Bengal. In contrast, the Arabian Sea, Indian Ocean, and South Indian continent are suggested as major source regions in summer. We also found daytime maxima of most diacids, except for C9 and t-Ph acids, which showed nighttime maxima in summer. Emissions from marine and terrestrial plants, combined with land/sea breezes and in situ photochemical oxidation, are suggested especially in summer as an important factor that controls the composition of water-soluble organic aerosols over the southeast coast of India. Regional emissions from anthropogenic sources are also important in megacity Chennai, but their influence is weakened due to the dispersion caused by dynamic land/sea breeze on the coast. Copyright 2010 by the American Geophysical Union.