scholarly journals Long-range transport of Saharan dust to northern Europe: The 11-16 October 2001 outbreak observed with EARLINET

2003 ◽  
Vol 108 (D24) ◽  
pp. n/a-n/a ◽  
Author(s):  
Albert Ansmann ◽  
Jens Bösenberg ◽  
Anatoli Chaikovsky ◽  
Adolfo Comerón ◽  
Sabine Eckhardt ◽  
...  
Keyword(s):  
Long Range ◽  
Saharan Dust ◽  
Northern Europe ◽  
Long Range Transport ◽  
Range Transport

scholarly journals Long range transport and mixing of aerosol sources during the 2013 North American biomass burning episode: analysis of multiple lidar observations in the Western Mediterranean basin

2015 ◽  
Vol 15 (22) ◽  
pp. 32323-32365 ◽  
Author(s):  
G. Ancellet ◽  
J. Pelon ◽  
J. Totems ◽  
P. Chazette ◽  
A. Bazureau ◽  
...  
Keyword(s):  
Long Range ◽  
Biomass Burning ◽  
North American ◽  
Western Mediterranean ◽  
Saharan Dust ◽  
Trade Wind ◽  
Long Range Transport ◽  
Range Transport ◽  
Aerosol Sources ◽  
Aerosol Source

Abstract. Long range transport of biomass burning (BB) aerosols between North America and the Mediterranean region took place in June 2013. A large number of ground based and airborne lidar measurements were deployed in the Western Mediterranean during the Chemistry-AeRosol Mediterranean EXperiment (ChArMEx) intensive observation period. A detailed analysis of the potential North American aerosol sources is conducted including the assessment of their transport to Europe using forward simulations of the FLEXPART Lagrangian particle dispersion model initialized using satellite observations by MODIS and CALIOP. The three dimensional structure of the aerosol distribution in the ChArMEx domain observed by the ground-based lidars (Menorca, Barcelona and Lampedusa), a Falcon-20 aircraft flight and three CALIOP tracks, agree very well with the model simulation of the three major sources considered in this work: Canadian and Colorado fires, a dust storm from Western US and the contribution of Saharan dust streamers advected from the North Atlantic trade wind region into the Westerlies region. Four aerosol types were identified using the optical properties of the observed aerosol layers (aerosol depolarization ratio, lidar ratio) and the transport model analysis of the contribution of each aerosol source: (I) pure BB layer, (II) weakly dusty BB, (III) significant mixture of BB and dust transported from the trade wind region (IV) the outflow of Saharan dust by the subtropical jet and not mixed with BB aerosol. The contribution of the Canadian fires is the major aerosol source during this episode while mixing of dust and BB is only significant at altitude above 5 km. The mixing corresponds to a 20–30 % dust contribution in the total aerosol backscatter. The comparison with the MODIS AOD horizontal distribution during this episode over the Western Mediterranean sea shows that the Canadian fires contribution were as large as the direct northward dust outflow from Sahara.

scholarly journals Long-Range Transport of Saharan Dust to East Asia Observed with Lidars

SOLA ◽  
2005 ◽  
Vol 1 ◽  
pp. 121-124 ◽  
Author(s):  
Chan Bong Park ◽  
Nobuo Sugimoto ◽  
Ichiro Matsui ◽  
Atsushi Shimizu ◽  
Boyan Tatarov ◽  
...  
Keyword(s):  
East Asia ◽  
Long Range ◽  
Saharan Dust ◽  
Long Range Transport ◽  
Range Transport

Long-Range Transport of Anthropogenically and Naturally Produced Particulate Matter in the Mediterranean and North Atlantic: Current State of Knowledge

2007 ◽  
Vol 46 (8) ◽  
pp. 1230-1251 ◽  
Author(s):  
George Kallos ◽  
Marina Astitha ◽  
Petros Katsafados ◽  
Chris Spyrou
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
North America ◽  
Atlantic Ocean ◽  
Long Range ◽  
Saharan Dust ◽  
Long Range Transport ◽  
Transport And Transformation ◽  
New Findings ◽  
Range Transport

Abstract During the past 20 years, organized experimental campaigns as well as continuous development and implementation of air-pollution modeling have led to significant gains in the understanding of the paths and scales of pollutant transport and transformation in the greater Mediterranean region (GMR). The work presented in this paper has two major objectives: 1) to summarize the existing knowledge on the transport paths of particulate matter (PM) in the GMR and 2) to illustrate some new findings related to the transport and transformation properties of PM in the GMR. Findings from previous studies indicate that anthropogenically produced air pollutants from European sources can be transported over long distances, reaching Africa, the Atlantic Ocean, and North America. The PM of natural origin, like Saharan dust, can be transported toward the Atlantic Ocean and North America mostly during the warm period of the year. Recent model simulations and studies in the area indicate that specific long-range transport patterns of aerosols, such as the transport from Asia and the Indian Ocean, central Africa, or America, have negligible or at best limited contribution to air-quality degradation in the GMR when compared with the other sources. Also, new findings from this work suggest that the imposed European Union limits on PM cannot be applicable for southern Europe unless the origin (natural or anthropogenic) of the PM is taken into account. The impacts of high PM levels in the GMR are not limited only to air quality, but also include serious implications for the water budget and the regional climate. These are issues that require extensive investigation because the processes involved are complex, and further model development is needed to include the relevant physicochemical processes properly.

scholarly journals Retrieval of microphysical dust particle properties from SALTRACE lidar observations: Case studies

2020 ◽  
Author(s):  
Stefanos Samaras ◽  
Christine Böckmann ◽  
Moritz Haarig ◽  
Albert Ansmann ◽  
Adrian Walser ◽  
...  
Keyword(s):  
Long Range ◽  
Software Tool ◽  
Total Surface Area ◽  
Saharan Dust ◽  
Radiation Budget ◽  
Dust Particles ◽  
Long Range Transport ◽  
Raman Lidar ◽  
Microphysical Properties ◽  
Range Transport

Abstract. Saharan dust is a major natural atmospheric aerosol component with significant impact on the Earth radiation budget. In this work we determine the microphysical properties of dust particles after a long-range transport over the Atlantic Ocean, using input from three depolarization channels of a multi-wavelength polarization Raman lidar. The measurements were performed at Barbados in the framework of the Saharan Aerosol Long-Range Transport and Aerosol–Cloud-Interaction Experiment (SALTRACE) in the summers of 2013 and 2014. The microphysical retrievals are performed with the software tool SphInX (Spheroidal Inversion Experiments) which uses regularization for the inversion process and a new two-dimensional (2-D) extension of the Mie model approximating dust with spheroids. The method allows us to simultaneously retrieve shape- and size-dependent particle distributions. Because dust particles are mostly non-spherical this software tool fills the gap in estimating the non-spherical particle fraction. Two cases measured on 10 July 2013 and 20 June 2014 are discussed. 2-D radius-bimodal shape-size distribution are retrieved. The ratio of spherical-to-non-spherical contributions to the particle number concentration was found to be about 3/7. A volume-weighted effective aspect ratio of 1.1 was obtained, indicating slightly prolate particles. The total effective radius for the two cases in the preselected radius range from 0.01–2.2 μm was found to be, on average, 0.75 μm. The stronger dust event (10 July 2013) showed about 24 % higher values for the total surface-area and volume concentration. Finally, we compare our results with the ones from the polarization lidar-photometer networking (POLIPHON) method and ground-based photometers as well as with airborne in situ particle counters. Considering all differences in these independent approaches, we find a qualitatively good agreement between the different results and a consistent description of the dust cases. Such an extensive comparison is a novel and fruitful exercise and corroborates that the mathematical retrieval based on Raman lidar data of particle backscattering, extinction, and depolarization is a powerful tool even in the case of dust particles.

scholarly journals Three years of aerosol mass, black carbon and particle number concentrations at Montsec (southern~Pyrenees, 1570 m a.s.l.)

2013 ◽  
Vol 13 (10) ◽  
pp. 27201-27241 ◽  
Author(s):  
A. Ripoll ◽  
J. Pey ◽  
M. C. Minguillón ◽  
N. Pérez ◽  
M. Pandolfi ◽  
...  
Keyword(s):  
Solar Radiation ◽  
High Altitude ◽  
Long Range ◽  
Central Europe ◽  
Time Variation ◽  
Particle Number ◽  
Saharan Dust ◽  
Long Range Transport ◽  
Anthropogenic Emissions ◽  
Range Transport

Abstract. Time variation of mass particulate matter (PM1 and PM1−10), black carbon (BC) and particle number (N) concentrations at the high altitude site of Montsec (MSC) in the southern Pyrenees was interpreted for the period 2010–2012. The MSC site registered higher PM10 (12 μg m−3) and N > 7 nm (2209 # cm−3) concentrations than those measured at other high altitude sites in central Europe (PM10: 3–9 μg m−3 and N: 634–2070 # cm−3). By contrast, BC concentrations at MSC (0.2 μg m−3) were equal or even lower than those measured at these European sites (0.2–0.4 μg m−3). These differences were attributed to the lower influence of anthropogenic emissions and to the higher relevance of Saharan dust transport and new particle formation (NPF) processes at MSC. The different time variation of PM and BC concentrations compared with that of N suggests that these aerosol parameters were governed by diverse factors at MSC. Both PM and BC concentrations showed marked differences for different meteorological scenarios, with enhanced concentrations under North African outbreaks (PM1−10: 13 μg m−3, PM1: 8 μg m−3 and BC: 0.3 μg m−3) and low concentrations when Atlantic advections occurred (PM1−10: 5 μg m−3, PM1: 4 μg m−3 and BC: 0.1 μg m−3). Because of the contrasting origin of the air masses in the warmer seasons (spring and summer) and in the colder seasons (autumn and winter), PM and BC concentrations showed a marked increase in summer, with a secondary maximum in early spring, and were at their lowest during winter. The maximum in the warmer seasons was attributed to long-range transport processes which mask the breezes and regional transport breaking the daily cycles of these pollutants. By contrast, PM and BC concentrations showed clear diurnal cycles with maxima at midday in the colder seasons. A statistically significant weekly variation was also obtained for the BC concentrations, displaying a progressive increase from Tuesday to Saturday, followed by a significant decrease on Sunday and Monday. N concentrations depended more on local meteorological variables such as solar radiation than on the air mass origin. Therefore, the highest concentrations of N were associated with summer regional episodes (N > 3 nm: 4461 # cm−3 and N > 7 nm: 3021 # cm−3) and the lowest concentrations were related to winter regional scenarios (N > 3 nm: 2496 # cm−3 and N > 7 nm: 1073 # cm−3). This dependence on solar radiation also accounted for the marked diurnal cycle of N concentrations throughout the year with a peak at midday and for the absence of a weekly pattern. Measurements carried out at MSC enabled us to characterize the tropospheric background aerosols in the Western Mediterranean Basin (WMB). Our results highlight the importance of the NPF processes in southern Europe, reveal much lower anthropogenic emissions than in central Europe, and underline the contribution of natural long-range transport such as Saharan dust.

scholarly journals Long-term chemical characterization of tropical and marine aerosols at the Cape Verde Atmospheric Observatory (CVAO) from 2007 to 2011

2014 ◽  
Vol 14 (17) ◽  
pp. 8883-8904 ◽  
Author(s):  
K. W. Fomba ◽  
K. Müller ◽  
D. van Pinxteren ◽  
L. Poulain ◽  
M. van Pinxteren ◽  
...  
Keyword(s):  
Long Range ◽  
Mineral Dust ◽  
Chemical Characterization ◽  
Sea Salt ◽  
Saharan Dust ◽  
Long Range Transport ◽  
Air Mass ◽  
Aerosol Mass ◽  
Range Transport

Abstract. The first long-term aerosol sampling and chemical characterization results from measurements at the Cape Verde Atmospheric Observatory (CVAO) on the island of São Vicente are presented and are discussed with respect to air mass origin and seasonal trends. In total 671 samples were collected using a high-volume PM10 sampler on quartz fiber filters from January 2007 to December 2011. The samples were analyzed for their aerosol chemical composition, including their ionic and organic constituents. Back trajectory analyses showed that the aerosol at CVAO was strongly influenced by emissions from Europe and Africa, with the latter often responsible for high mineral dust loading. Sea salt and mineral dust dominated the aerosol mass and made up in total about 80% of the aerosol mass. The 5-year PM10 mean was 47.1 ± 55.5 μg m−2, while the mineral dust and sea salt means were 27.9 ± 48.7 and 11.1 ± 5.5 μg m−2, respectively. Non-sea-salt (nss) sulfate made up 62% of the total sulfate and originated from both long-range transport from Africa or Europe and marine sources. Strong seasonal variation was observed for the aerosol components. While nitrate showed no clear seasonal variation with an annual mean of 1.1 ± 0.6 μg m−3, the aerosol mass, OC (organic carbon) and EC (elemental carbon), showed strong winter maxima due to strong influence of African air mass inflow. Additionally during summer, elevated concentrations of OM were observed originating from marine emissions. A summer maximum was observed for non-sea-salt sulfate and was connected to periods when air mass inflow was predominantly of marine origin, indicating that marine biogenic emissions were a significant source. Ammonium showed a distinct maximum in spring and coincided with ocean surface water chlorophyll a concentrations. Good correlations were also observed between nss-sulfate and oxalate during the summer and winter seasons, indicating a likely photochemical in-cloud processing of the marine and anthropogenic precursors of these species. High temporal variability was observed in both chloride and bromide depletion, differing significantly within the seasons, air mass history and Saharan dust concentration. Chloride (bromide) depletion varied from 8.8 ± 8.5% (62 ± 42%) in Saharan-dust-dominated air mass to 30 \\textpm 12% (87 ± 11%) in polluted Europe air masses. During summer, bromide depletion often reached 100% in marine as well as in polluted continental samples. In addition to the influence of the aerosol acidic components, photochemistry was one of the main drivers of halogenide depletion during the summer; while during dust events, displacement reaction with nitric acid was found to be the dominant mechanism. Positive matrix factorization (PMF) analysis identified three major aerosol sources: sea salt, aged sea salt and long-range transport. The ionic budget was dominated by the first two of these factors, while the long-range transport factor could only account for about 14% of the total observed ionic mass.

scholarly journals Saharan dust long-range transport across the Atlantic studied by an airborne Doppler wind lidar and the MACC model

2016 ◽  
Vol 16 (18) ◽  
pp. 11581-11600 ◽  
Author(s):  
Fernando Chouza ◽  
Oliver Reitebuch ◽  
Angela Benedetti ◽  
Bernadett Weinzierl
Keyword(s):  
Long Range ◽  
Marine Boundary Layer ◽  
Saharan Dust ◽  
Long Range Transport ◽  
Aerosol Model ◽  
Range Transport ◽  
Wind Lidar ◽  
The Caribbean ◽  
June July ◽  
Good Agreement

Abstract. A huge amount of dust is transported every year from north Africa into the Caribbean region. This paper presents an investigation of this long-range transport process based on airborne Doppler wind lidar (DWL) measurements conducted during the SALTRACE campaign (June–July 2013), as well as an evaluation of the ability of the MACC (Monitoring Atmospheric Composition and Climate) global aerosol model to reproduce it and its associated features. Although both the modeled winds from MACC and the measurements from the DWL show a generally good agreement, some differences, particularly in the African easterly jet (AEJ) intensity, were noted. The observed differences between modeled and measured wind jet speeds are between 5 and 10 m s−1. The vertical aerosol distribution within the Saharan dust plume and the marine boundary layer is investigated during the June–July 2013 period based on the MACC aerosol model results and the CALIOP satellite lidar measurements. While the modeled Saharan dust plume extent shows a good agreement with the measurements, a systematic underestimation of the marine boundary layer extinction is observed. Additionally, three selected case studies covering different aspects of the Saharan dust long-range transport along the west African coast, over the North Atlantic Ocean and the Caribbean are presented. For the first time, DWL measurements are used to investigate the Saharan dust long-range transport. Simultaneous wind and backscatter measurements from the DWL are used, in combination with the MACC model, to analyze different features associated with the long-range transport, including an African easterly wave trough, the AEJ and the intertropical convergence zone.

scholarly journals Long-range transport and mixing of aerosol sources during the 2013 North American biomass burning episode: analysis of multiple lidar observations in the western Mediterranean basin

2016 ◽  
Vol 16 (7) ◽  
pp. 4725-4742 ◽  
Author(s):  
Gerard Ancellet ◽  
Jacques Pelon ◽  
Julien Totems ◽  
Patrick Chazette ◽  
Ariane Bazureau ◽  
...  
Keyword(s):  
Long Range ◽  
Biomass Burning ◽  
North American ◽  
Western Mediterranean ◽  
Saharan Dust ◽  
Trade Wind ◽  
Long Range Transport ◽  
Range Transport ◽  
Aerosol Sources ◽  
Aerosol Source

Abstract. Long-range transport of biomass burning (BB) aerosols between North America and the Mediterranean region took place in June 2013. A large number of ground-based and airborne lidar measurements were deployed in the western Mediterranean during the Chemistry-AeRosol Mediterranean EXperiment (ChArMEx) intensive observation period. A detailed analysis of the potential North American aerosol sources is conducted including the assessment of their transport to Europe using forward simulations of the FLEXPART Lagrangian particle dispersion model initialized using satellite observations by MODIS and CALIOP. The three-dimensional structure of the aerosol distribution in the ChArMEx domain observed by the ground-based lidars (Minorca, Barcelona and Lampedusa), a Falcon-20 aircraft flight and three CALIOP tracks, agrees very well with the model simulation of the three major sources considered in this work: Canadian and Colorado fires, a dust storm from western US and the contribution of Saharan dust streamers advected from the North Atlantic trade wind region into the westerlies region. Four aerosol types were identified using the optical properties of the observed aerosol layers (aerosol depolarization ratio, lidar ratio) and the transport model analysis of the contribution of each aerosol source: (i) pure BB layer, (ii) weakly dusty BB, (iii) significant mixture of BB and dust transported from the trade wind region, and (iv) the outflow of Saharan dust by the subtropical jet and not mixed with BB aerosol. The contribution of the Canadian fires is the major aerosol source during this episode while mixing of dust and BB is only significant at an altitude above 5 km. The mixing corresponds to a 20–30 % dust contribution in the total aerosol backscatter. The comparison with the MODIS aerosol optical depth horizontal distribution during this episode over the western Mediterranean Sea shows that the Canadian fire contributions were as large as the direct northward dust outflow from Sahara.

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