Long-range transport of Saharan dust over northwestern Europe during EUCAARI 2008 campaign: Evolution of dust optical properties by scavenging

Abstract. As a part of the IGAC (International Global Atmospheric Chemistry) Mega-cities program, aerosol physical and optical properties were continuously measured from March 2007 to March 2008 at an urban site (37.57° N, 126.94° E) in Seoul, Korea. Spectral optical properties of long-range transported Asian dust and pollution aerosols have been investigated based on the year long measurement data. Optically measured black carbon/thermally measured elemental carbon (BC/EC) ratio showed clear monthly variation with high values in summer and low values in winter mainly due to the enhancement of light attenuation by the internal mixing of EC. Novel approach has been suggested to retrieve the spectral light absorption coefficient (babs) from Aethalometer raw data by using BC/EC ratio. Mass absorption efficiency, σabs (=babs/EC) at 550 nm was determined to be 9.0±1.3, 8.9±1.5, 9.5±2.0, and 10.3±1.7 m2 g−1 in spring, summer, fall, and winter, respectively with an annual mean of 9.4±1.8 m2 g−1. Threshold values to classify severe haze events were suggested in this study. Increasing trend of aerosol single scattering albedo (SSA) with wavelength was observed during Asian dust events while little spectral dependence of SSA was observed during long-range transport pollution (LTP) events. Satellite aerosol optical thickness (AOT) and Hysplit air mass backward trajectory analyses as well as chemical analysis were performed to characterize the dependence of spectral optical properties on aerosol type. Results from this study can provide useful information for studies on regional air quality and aerosol's effects on climate change.

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Insights into the aging of biomass burning aerosol from satellite observations and 3D atmospheric modeling: evolution of the aerosol optical properties in Siberian wildfire plumes

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-357-2021 ◽

2021 ◽

Vol 21 (1) ◽

pp. 357-392

Author(s):

Igor B. Konovalov ◽

Nikolai A. Golovushkin ◽

Matthias Beekmann ◽

Meinrat O. Andreae

Keyword(s):

Optical Properties ◽

Long Range ◽

Biomass Burning ◽

Organic Aerosol ◽

Satellite Observations ◽

Long Range Transport ◽

Aerosol Optical Properties ◽

Smoke Plumes ◽

Range Transport ◽

Aerosol Aging

Abstract. Long-range transport of biomass burning (BB) aerosol from regions affected by wildfires is known to have a significant impact on the radiative balance and air quality in receptor regions. However, the changes that occur in the optical properties of BB aerosol during long-range transport events are insufficiently understood, limiting the adequacy of representations of the aerosol processes in chemistry transport and climate models. Here we introduce a framework to infer and interpret changes in the optical properties of BB aerosol from satellite observations of multiple BB plumes. Our framework includes (1) a procedure for analysis of available satellite retrievals of the absorption and extinction aerosol optical depths (AAOD and AOD) and single-scattering albedo (SSA) as a function of the BB aerosol photochemical age and (2) a representation of the AAOD and AOD evolution with a chemistry transport model (CTM) involving a simplified volatility basis set (VBS) scheme with a few adjustable parameters. We apply this framework to analyze a large-scale outflow of BB smoke plumes from Siberia toward Europe that occurred in July 2016. We use AAOD and SSA data derived from OMI (Ozone Monitoring Instrument) satellite measurements in the near-UV range along with 550 nm AOD and carbon monoxide (CO) columns retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) and IASI (Infrared Atmospheric Sounding Interferometer) satellite observations, respectively, to infer changes in the optical properties of Siberian BB aerosol due to its atmospheric aging and to get insights into the processes underlying these changes. Using the satellite data in combination with simulated data from the CHIMERE CTM, we evaluate the enhancement ratios (EnRs) that allow isolating AAOD and AOD changes due to oxidation and gas–particle partitioning processes from those due to other processes, including transport, deposition, and wet scavenging. The behavior of EnRs for AAOD and AOD is then characterized using nonlinear trend analysis. It is found that the EnR for AOD strongly increases (by about a factor of 2) during the first 20–30 h of the analyzed evolution period, whereas the EnR for AAOD does not exhibit a statistically significant increase during this period. The increase in AOD is accompanied by a statistically significant enhancement of SSA. Further BB aerosol aging (up to several days) is associated with a strong decrease in EnRs for both AAOD and AOD. Our VBS simulations constrained by the observations are found to be more consistent with satellite observations of strongly aged BB plumes than “tracer” simulations in which atmospheric transformations of BB organic aerosol were disregarded. The simulation results indicate that the upward trends in EnR for AOD and in SSA are mainly due to atmospheric processing of secondary organic aerosol (SOA), leading to an increase in the mass scattering efficiency of BB aerosol. Evaporation and chemical fragmentation of the SOA species, part of which is assumed to be absorptive (to contain brown carbon), are identified as likely reasons for the subsequent decrease in the EnR for both AAOD and AOD. Hence, our analysis reveals that the long-range transport of smoke plumes from Siberian fires is associated with major changes in BB aerosol optical properties and chemical composition. Overall, this study demonstrates the feasibility of using available satellite observations for evaluating and improving representations in atmospheric models of the BB aerosol aging processes in different regions of the world at much larger temporal scales than those typically addressed in aerosol chamber experiments.

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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

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-32323-2015 ◽

2015 ◽

Vol 15 (22) ◽

pp. 32323-32365 ◽

Cited By ~ 5

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.

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

SOLA ◽

10.2151/sola.2005-032 ◽

2005 ◽

Vol 1 ◽

pp. 121-124 ◽

Cited By ~ 13

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

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Aerosol optical properties at Mauna Loa Observatory: Long-range transport from Kuwait?

Geophysical Research Letters ◽

10.1029/92gl00524 ◽

1992 ◽

Vol 19 (6) ◽

pp. 581-584 ◽

Cited By ~ 29

Author(s):

B. A. Bodhaine ◽

J. M. Harris ◽

J. A. Ogren ◽

D. J. Hofmann

Keyword(s):

Optical Properties ◽

Long Range ◽

Long Range Transport ◽

Aerosol Optical Properties ◽

Mauna Loa ◽

Range Transport

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Long-range transport of Saharan dust and its radiative impact on precipitation forecast: a case study during the Convective and Orographically-induced Precipitation Study (COPS)

Quarterly Journal of the Royal Meteorological Society ◽

10.1002/qj.719 ◽

2011 ◽

Vol 137 (S1) ◽

pp. 236-251 ◽

Cited By ~ 47

Author(s):

Jean-Pierre Chaboureau ◽

Evelyne Richard ◽

Jean-Pierre Pinty ◽

Cyrille Flamant ◽

Paolo Di Girolamo ◽

...

Keyword(s):

Long Range ◽

Saharan Dust ◽

Precipitation Forecast ◽

Long Range Transport ◽

Radiative Impact ◽

Range Transport

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

Journal of Applied Meteorology and Climatology ◽

10.1175/jam2530.1 ◽

2007 ◽

Vol 46 (8) ◽

pp. 1230-1251 ◽

Cited By ~ 146

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.

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

Journal of Geophysical Research Atmospheres ◽

10.1029/2003jd003757 ◽

2003 ◽

Vol 108 (D24) ◽

pp. n/a-n/a ◽

Cited By ~ 175

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

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

10.5194/acp-2020-459 ◽

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.

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