Extraordinary dust event over Beijing, China, during April 2006: Lidar, Sun photometric, satellite observations and model validation

Papayannis, A.; Zhang, H. Q.; Amiridis, Vassilis; Ju, Hongrun; Chourdakis, G.; Georgoussis, G.; García‐Pando, Carlos Pérez; Chen, H. B.; Goloub, Philippe; Mamouri, Rodanthi-Elisavet; Kazadzis, Stelios; Paronis, D.; Tsaknakis, G.; Baldasano, J. M.

doi:10.1029/2006gl029125

Cited by 53 publications

(31 citation statements)

References 21 publications

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“…Again, the Lidar reveals a more complex layering than that forecast by DREAM. Similar behaviour was observed during an extraordinary dust event over Beijing (China) in April 2006 (Papayannis et al, 2007). The differences between the Lidar and the DREAM model are more obvious during the rest of this Saharan dust event, when optical properties achieve values lower than those on 6 September, especially at the lowest altitudes.…”

Section: Vertical Profiles By Active Remote Sensingsupporting

confidence: 66%

Extreme Saharan dust event over the southern Iberian Peninsula in september 2007: active and passive remote sensing from surface and satellite

et al. 2009

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Abstract. This study investigates aerosol optical properties during the extreme Saharan dust event detected from 3 to 7 September 2007 over Granada, southern Iberian Peninsula, with both active and passive remote sensing instrumentation from surface and satellite. The intensity of the event was visualized on the aerosol optical depth series obtained by the sun-photometer Cimel CE 318-4 operated at Granada in the framework of AERONET from August 2004 until December 2008 (level 2 data). A combination of large aerosol optical depth (0.86-1.50) at 500 nm, and reduced Angström exponent (0.1-0.25) in the range 440-870 nm, was detected on 6 September during daytime. This Saharan dust event also affected other Iberian Peninsula stations included in AERONET (El Arenosillo andÉvora stations), and it was monitored by MODIS instrument on board Aqua satellite. Vertically resolved measurements were performed by a ground-based Raman Lidar and by CALIPSO satellite. During the most intense stage, on 6 September, maximum aerosol backscatter values were a factor of 8 higher than other maxima during this Saharan dust event. Values up to 1.5×10 −2 km −1 sr −1 at 355 and 532 nm were detected in the layer with the greatest aerosol load between 3-4 km a.s.l., although aerosol particles were also detected up to 5.5 km a.s.l. In this stage of the event, dust particles at these altitudes showed a backscatter-related Angström exponent between −0.44 and 0.53 for the two spectral intervals considered. The results from different measurements (active/passive and Correspondence to: L. Alados Arboledas (alados@ugr.es) ground-based/satellite) reveal the importance of performing multi-instrumental measurements to properly characterize the contribution of different aerosol types from different sources during extreme events. The atmospheric stabilization effect of the aerosol particles has been characterized by computing the solar heating rates using SBDART code.

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Section: Vertical Profiles By Active Remote Sensingsupporting

confidence: 66%

Extreme Saharan dust event over the southern Iberian Peninsula in september 2007: active and passive remote sensing from surface and satellite

et al. 2009

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“…This threshold was set to discriminate between small and moderate to strong dust events, in consistency with dust models and previous observations (Tegen, 2003;Kaskaoutis et al, 2007;Papayannis et al, 2007a;Greed et al, 2008). In that way we selected to analyze the aerosol lidar measurements only for the strong dust days.…”

Section: Dust Events Occurrencesmentioning

confidence: 99%

Systematic lidar observations of Saharan dust layers over Athens, Greece in the frame of EARLINET project (2004–2006)

et al. 2009

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Abstract. In this paper we present a statistical analysis on the geometrical and optical properties of Saharan dust layers observed over Athens, Greece, in a three-year period from 1 January 2004 up to 31 December 2006. The observations of the vertical aerosol profile were performed by the multi-wavelength (355-532-1064-387-607 nm) Raman lidar system of the National Technical University of Athens (NTUA) operated in the city of Athens (37 • 98 N, 23 • 77 E), Greece, in the frame of the European Aerosol Research Lidar Network (EARLINET-ASOS) project. The number of dust events was greatest in late spring, summer, and early autumn periods. This was evident also by aerosol observations during dust outbreaks obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS). In our lidar measurements, multiple aerosol dust layers of variable thickness (680-4800 m) were observed. The center of mass of these layers was located in altitudes between 1600 and 5800 m. However, the mean thickness of the dust layer typically stayed around 2700 m and the corresponding mean center of mass was of the order of 2900 m. The top of the dust layer ranged from 2000 to 8000 m, with a mean value of the order of 4700 m. MODIS observations during dust outbreaks showed that the AOD values at 550 nm ranged between 0.3-0.6, while the corresponding Angström exponent (AE) values were of the order of 0.5-0.65, indicating the presence of rather large particles.

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“…On the other hand, if the dust is first transported over industrial regions, as during 15-20 April 2006 when dust was a serious problem for the Beijing region (e.g. Papayannis et al, 2007), and the mix of fine and coarse particles enters a cloud, then for the cloud scavenging hypothesis to be the sole viable explanation of the loss of fine particle organics the coarse particles must be scavenged much less efficiently than the fine particles, i.e. they must not increase significantly in size due to water condensation.…”

Section: Organic Matter On Dust Particlesmentioning

confidence: 99%

Evidence for Asian dust effects from aerosol plume measurements during INTEX-B 2006 near Whistler, BC

et al. 2009

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Abstract. Several cases of aerosol plumes resulting from trans-Pacific transport were observed between 2 km and 5.3 km at Whistler, BC from 22 April 2006 to 15 May 2006. The fine particle (<1 µm) chemical composition of most of the plumes was dominated by sulphate that ranged from 1-5 µg m −3 as measured with a Quadrapole Aerosol Mass Spectrometer (Q-AMS). Coarse particles (>1 µm) were enhanced in all sulphate plumes. Fine particle organic mass concentrations were relatively low in most plumes and were nominally anti-correlated with the increases in the number concentrations of coarse particles. The ion chemistry of coarse particles sampled at Whistler Peak was dominated by calcium, sodium, nitrate, sulphate and formate. Scanning transmission X-ray microscopy of coarse particles sampled from the NCAR C-130 aircraft relatively close to Whistler indicated carbonate, potassium and organic functional groups, in particular the carboxyl group. Asian plumes reaching Whistler, BC during the INTEX-B study were not only significantly reduced of fine particle organic material, but organic compounds were attached to coarse particles in significant quantities. Suspension of dust with deposited organic material and scavenging of organic materials by dust near anthropogenic sources are suggested, and if any secondary organic aerosol (SOA) was formed during transport from Asian source regions across the Pacific it was princiCorrespondence to: W. R. Leaitch (Richard.Leaitch@ec.gc.ca) pally associated with the coarse particles. An average of profiles indicates that trans-Pacific transport between 2 and 5 km during this period increased ozone by about 10 ppbv and fine particle sulphate by 0.2-0.5 µg m −3 . The mean sizes of the fine particles in the sulphate plumes were larger when dust particles were present and smaller when the fine particle organic mass concentration was larger and dust was absent. The coarse particles of dust act to accumulate sulphate, nitrate and organic material in larger particles, diminishing the role of these compounds in indirect radiative forcing, but potentially enhancing their roles in direct radiative forcing.

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Extraordinary dust event over Beijing, China, during April 2006: Lidar, Sun photometric, satellite observations and model validation

Cited by 53 publications

References 21 publications

Extreme Saharan dust event over the southern Iberian Peninsula in september 2007: active and passive remote sensing from surface and satellite

Extreme Saharan dust event over the southern Iberian Peninsula in september 2007: active and passive remote sensing from surface and satellite

Systematic lidar observations of Saharan dust layers over Athens, Greece in the frame of EARLINET project (2004–2006)

Evidence for Asian dust effects from aerosol plume measurements during INTEX-B 2006 near Whistler, BC

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