Aerosol optical properties during dust and biomass burning episodes retrieved from sun-photometer over Shanghai

Abstract. Ground-based observation over Shanghai was carried out from 28 March to 25 June 2013 in an urban site at Fudan University (31°18' N, 121°29' E). Utilizing a sun/sky radiometer (CE318), aerosol properties including thickness, scattering, asymmetry, and particle size distribution were inversed for two types (dust and biomass burning). Dust aerosol showed large optical depth (AOD at 440 nm ~ 1.06) with small value of Ångström parameter (α) around 0.74, indicating the strong optical extinction capability of large-size particles. Aerosol loading (~ 0.72 at 440 nm) was discovered to be coupled with large α (> 1.05) for biomass smoke. The particle size distribution was dominated by the coarse mode for dust with high concentration ratio between coarse and fine mode (VC/VF ~ 3.76). Biomass burning particle primarily accumulated around 0.17 μm and performed smaller VC/VF (~ 0.99). Aerosol in fine mode mainly accounted for the optical extinction process in Shanghai as its volume concentration was well-correlated with AOD (R ~ 0.88 in average condition). The value of single scattering albedo (SSA) during agricultural residue burning displayed variation from 0.902 to 0.922 with a descending trend at 670–1020 nm while SSA increased at all wavelengths for dust aerosol. The negative correlation between SSA · AOD and α was analyzed to capture the order of scattering capability: urban/industrial < biomass < dust aerosol. Higher value of asymmetry factor at 1020 nm (~ 0.652) of dust aerosol was found compared to average condition and biomass smoke (both were equaled to 0.625), imposing the enhanced forward scattering of dust particles in NIR band. The validation of AOD vs. MODIS showed errors in dust and biomass samples, which may be attributed to the variable SSA in YRD. The ascending deviation also existed in clear condition, which could be caused by the overestimation of ground reflectance in MODIS algorithm.

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Modeling of particle size distribution and its influence on the radiative properties of mineral dust aerosol

Journal of Geophysical Research Atmospheres ◽

10.1029/95jd03610 ◽

1996 ◽

Vol 101 (D14) ◽

pp. 19237-19244 ◽

Cited By ~ 433

Author(s):

Ina Tegen ◽

Andrew A. Lacis

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Mineral Dust ◽

Dust Aerosol ◽

Radiative Properties

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Column-integrated aerosol microphysical properties from AERONET Sun photometer over Southwestern Spain

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-18349-2011 ◽

2011 ◽

Vol 11 (6) ◽

pp. 18349-18384 ◽

Cited By ~ 2

Author(s):

N. Prats ◽

V. E. Cachorro ◽

A. Berjón ◽

C. Toledano ◽

A. M. De Frutos

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Volume Fraction ◽

Effective Radius ◽

Desert Dust ◽

Microphysical Properties ◽

Coarse Mode ◽

Fine Mode ◽

Sun Photometer

Abstract. The aim of the present work is to carry out a detailed analysis of columnar microphysical properties obtained from Cimel sun-photometer measurements in the Southwest of Spain within the frame of the AERONET-RIMA network. AERONET inversion products are analysed, in particular the particle size distribution together with their associated microphysical parameters for both fine and coarse modes: concentration, effective radius and the fine mode volume fraction. This work complements previous works based on aerosol optical depth (AOD) and the Ångström exponent (AE) for a global characterization of atmospheric aerosol in this representative area of Spain and Europe. The analysed dataset spans between February 2000 and October 2008. Time series and statistical analysis has been carried out for these parameters in order to assess their typical values and seasonality together with their relationships with the AOD and AE. Mean values of volume particle concentration are 0.06 ± 0.07 μm3 μm−2 for total, 0.019 ± 0.015 μm3 μm−2 for fine and 0.04 ± 0.06 μm3 μm−2 for coarse mode; and of effective radius are 0.040 ± 0.19 μm for total, 0.14 ± 0.02 μm for fine and 1.96 ± 0.41 μm for coarse mode. The most relevant features are the clear bimodality of the volume particle size distribution, with a slight dominance of the coarse mode for the total climatology and under the prevailing atmospheric conditions of the site (coastal marine). There is a clear prevalence of the coarse mode in summer months, September and March in coincidence with the occurrence of desert dust intrusions and highest AOD values. During aerosol desert dust arrivals, the particle size distribution is practically mono-modal with strong prevalence of the coarse mode which also shows a shift of the modal radius to lower values. The size particle predominance defines the characteristic of the site and it has been analysed under two different approaches: with respect to particle number, using the Ångström exponent and with respect to particle volume, where the fine mode volume fraction Vf/Vt is taken.

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Column-integrated aerosol microphysical properties from AERONET Sun photometer over southwestern Spain

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-12535-2011 ◽

2011 ◽

Vol 11 (24) ◽

pp. 12535-12547 ◽

Cited By ~ 30

Author(s):

N. Prats ◽

V. E. Cachorro ◽

A. Berjón ◽

C. Toledano ◽

A. M. De Frutos

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Volume Fraction ◽

Effective Radius ◽

Desert Dust ◽

Microphysical Properties ◽

Coarse Mode ◽

Fine Mode ◽

Sun Photometer

Abstract. The aim of the present work is to carry out a detailed analysis of columnar microphysical properties obtained from Cimel sun-photometer measurements in the Southwest of Spain within the frame of the Aerosol Robotic Network (AERONET) – Iberian Network for aerosol measurements (RIMA). AERONET level 2 inversion products are analysed, in particular the particle size distribution together with their associated microphysical parameters for both fine and coarse modes: volume concentration, effective radius and the fine mode volume fraction. This work complements previous works based on aerosol optical depth (AOD) and the Ångström exponent (AE) for a global characterization of atmospheric aerosol in this area of southwestern Spain. The analysed dataset spans between February 2000 and October 2008. Time series and statistical analysis has been carried out for these parameters in order to assess their typical values and seasonality together with their relationships with the AOD and AE. Mean values of volume particle concentration are 0.06±0.07 μm3 μm−2 for total, 0.019±0.015 μm3 μm−2 for fine and 0.04±0.06 μm3 μm−2 for coarse mode; mean effective radii are 0.40±0.19 μm for total, 0.14±0.02 μm for fine and 1.96±0.41 μm for coarse mode. The most relevant features are the clear bimodality of the volume particle size distribution, with a slight dominance of the coarse mode in the overall climatology given the prevailing atmospheric conditions at the site (coastal marine). There is a clear prevalence of the coarse mode in summer months plus September and March, in coincidence with the occurrence of desert dust intrusions and highest AOD values. During desert dust outbreaks, the particle size distribution is practically monomodal with strong prevalence of the coarse mode which also shows a shift of the modal radius toward lower values. The size particle predominance defines the characteristic of the site and it has been analysed under two different parameters: the Ångström exponent and the fine mode volume fraction Vf/Vt. We investigated the relationship between them and also their relationship with the effective radius of the size distribution.

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Inversion of visible optical extinction data for spheroid particle size distribution based on PCA

Optik ◽

10.1016/j.ijleo.2014.04.083 ◽

2014 ◽

Vol 125 (19) ◽

pp. 5494-5507 ◽

Cited By ~ 5

Author(s):

Hong Tang ◽

Jian-zhong Lin

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Extinction Data ◽

Optical Extinction ◽

Spheroid Particle

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Variations of aerosol properties due to regional source contributions and impacts on ozone levels:a study in a south China city

Environmental Chemistry ◽

10.1071/en10020 ◽

2010 ◽

Vol 7 (4) ◽

pp. 359 ◽

Cited By ~ 6

Author(s):

Ka-Ming Wai ◽

Peter A. Tanner

Keyword(s):

Particle Size ◽

Hong Kong ◽

Particle Size Distribution ◽

Size Distribution ◽

Biomass Burning ◽

Ozone Concentration ◽

Dust Storms ◽

Transfer Model ◽

Industrial Activities ◽

Aerosol Properties

Environmental context.Regional atmospheric contaminants from both anthropogenic and natural events (industrial activities, biomass burning, dust events) can have large impacts on the aerosol properties of distant downwind sites. Data showing the influence of regional sources on air quality in Hong Hong are presented. In particular, the changes in aerosol properties (e.g. mass concentration and particle size distribution), and their effects on photochemical ozone formation, is discussed. Abstract.Variations of PM10 concentration and particle size distribution owing to the influence of industrial activities in mainland China, biomass burning in South East Asia and dust storms in north-west China, as well as the aerosol impact on surface ozone concentration, have been studied by a combination of analysis of air mass origin (by back-trajectory calculation), remote sensing techniques, regional chemical transport and photochemical box models. The PM10 concentrations in Hong Kong were reduced by 24–57% owing to the industrial downtime during the Chinese New Year period. A photochemical box model coupled with a radiative transfer model has been employed to predict surface maximum ozone concentrations during high aerosol loading days. Increase of aerosol optical depth can lead to 7–32% reduction of surface maximum ozone concentration. Our results emphasise the need for regional cooperation in tackling the local air pollution of Hong Kong.

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