Vertical distributions of aerosol optical properties during haze and floating dust weather in Shanghai

Abstract. Aerosol optical properties were obtained from ground-based sunphotometer data at nine observatories over North China during two periods of 1996–1998 and 2002–2003. The seasonal changes of aerosol optical depth (AOD) at five wavelengths were observed, with the highest value of AOD in spring, while the lowest in winter. Four patterns of AOD diurnal variation were obtained, of which the high value occurred in the morning, noon, evening and no remarkable change, respectively. Together with meteorological records, the characteristics of AOD during dust weather were analyzed, and the results show that it was more detailed and accurate to use AOD to depict the strength change of dust weather than to use surface visibility. Based on measurements by aerodynamic instrument for particle size distribution, a positive correlation between dust particle number concentration and Ångström turbidity coefficient β, and a negative correlation between aerosol geometric mean diameter (GMD) and wavelength exponent αwere revealed.

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Vertical distributions of aerosol optical properties during the spring 2016 ARIAs airborne campaign in the North China Plain

10.5194/acp-2017-1021 ◽

2018 ◽

Author(s):

Fei Wang ◽

Zhanqing Li ◽

Xinrong Ren ◽

Qi Jiang ◽

Hao He ◽

...

Keyword(s):

Optical Properties ◽

North China Plain ◽

North China ◽

Aerosol Optical Properties ◽

Air Masses ◽

Scattering Coefficients ◽

The North ◽

The North China Plain ◽

Aerosol Scattering ◽

Vertical Distributions

Abstract. Vertical distributions of aerosol optical properties derived from measurements made during 11 aircraft flights over the North China Plain (NCP) in May–June 2016 during the Air Chemistry Research In Asia (ARIAs) were analyzed. Aerosol optical data from in situ aircraft measurements shows good correlation with ground-based measurements. The regional variability of aerosol optical profiles such as aerosol scattering and backscattering, absorption, extinction, single scattering albedo (SSA), and the Ångström exponent (α) are for the first time thoroughly characterized over the NCP. The SSA at 550 nm showed a regional mean value of 0.85 ± 0.02 with moderate to strong absorption and the α ranged from 0.49 to 2.53 (median 1.53) indicating both mineral dust and accumulation mode aerosols. Most of the aerosol particles were located in the lowest 2 km of the atmosphere. We describe three typical planetary boundary layer (PBL) scenarios and associated transport pathways as well as the correlation between aerosol scattering coefficients and relative humidity (RH). Aerosol scattering coefficients decreased slowly with height in the clean PBL condition, but decreased sharply above the PBL under polluted conditions, which showed a strong correlation (R2 &geq; 0.78) with ambient RH. Back-trajectory analysis shows that clean air masses generally originated from the distant north-western part of China while most of the polluted air masses were from the heavily polluted interior and coastal areas near the campaign area.

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Vertical distributions of aerosol optical properties during the spring 2016 ARIAs airborne campaign in the North China Plain

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-8995-2018 ◽

2018 ◽

Vol 18 (12) ◽

pp. 8995-9010 ◽

Cited By ~ 8

Author(s):

Fei Wang ◽

Zhanqing Li ◽

Xinrong Ren ◽

Qi Jiang ◽

Hao He ◽

...

Keyword(s):

Optical Properties ◽

North China Plain ◽

North China ◽

Aerosol Optical Properties ◽

Air Masses ◽

Scattering Coefficients ◽

The North ◽

The North China Plain ◽

Aerosol Scattering ◽

Vertical Distributions

Abstract. Vertical distributions of aerosol optical properties derived from measurements made during 11 aircraft flights over the North China Plain (NCP) in May–June 2016 during the Air Chemistry Research In Asia (ARIAs) were analyzed. Aerosol optical data from in situ aircraft measurements show good correlation with ground-based measurements. The regional variability of aerosol optical profiles such as aerosol scattering and backscattering, absorption, extinction, single scattering albedo (SSA), and the Ångström exponent (α) are thoroughly characterized for the first time over the NCP. The SSA at 550 nm showed a regional mean value of 0.85 ± 0.02 with moderate to strong absorption and the α ranged from 0.49 to 2.53 (median 1.53), indicating both mineral dust and accumulation-mode aerosols. Most of the aerosol particles were located in the lowest 2 km of the atmosphere. We describe three typical planetary boundary layer (PBL) scenarios and associated transport pathways as well as the correlation between aerosol scattering coefficients and relative humidity (RH). Aerosol scattering coefficients decreased slowly with height in the clean PBL condition, but decreased sharply above the PBL under polluted conditions, which showed a strong correlation (R2 ≥ 0.78) with ambient RH. Back-trajectory analysis shows that clean air masses generally originated from the distant northwestern part of China, while most of the polluted air masses were from the heavily polluted interior and coastal areas near the campaign region.

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Comparison of surface and column measurements of aerosol scattering properties over the western North Atlantic Ocean at Bermuda

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-1791-2014 ◽

2014 ◽

Vol 14 (2) ◽

pp. 1791-1821

Author(s):

R. P. Aryal ◽

K. J. Voss ◽

P. A. Terman ◽

W. C. Keene ◽

J. L. Moody ◽

...

Keyword(s):

Optical Properties ◽

Light Scattering ◽

North Atlantic Ocean ◽

Complex Refractive Index ◽

Submicron Particles ◽

Physical Factors ◽

Aerosol Optical Properties ◽

Near Surface ◽

Relative Contribution ◽

Vertical Distributions

Abstract. Light scattering and spectral absorption by size-resolved aerosols in near-surface air at Tudor Hill, Bermuda were measured continuously between January and June 2009. Vertical distributions of aerosol backscattering and column-averaged aerosol optical properties were characterized in parallel with a Micro-pulse lidar (MPL) and an automated sun-sky radiometer. Aerosol optical properties measured near the surface were often significantly correlated with those averaged over the column. These include scattering by near-surface bulk aerosol at 530 nm vs. column aerosol optical depth (AOD), near-surface sub-μm scattering fraction vs. column averaged sub-μm scattering fraction, the column averaged Angstrom exponent derived using a column integrated size distribution and complex refractive index. The relative contribution of submicron aerosol light scattering to total aerosol light scattering shows a slight enhancement of the column contribution of submicron particles over the surface measurements. Physical factors such as surface level wind speed have a more important affect on bulk aerosol light scattering at the surface.

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