干旱区生态环境知识资源中心(Arid): Multi-year analysis of aerosol optical properties at various timescales using AERONET data in tropical West Africa

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DOI	10.1016/j.jaerosci.2020.105625
	Multi-year analysis of aerosol optical properties at various timescales using AERONET data in tropical West Africa
	Yusuf, Najib; Said, Rabia S.; Tilmes, Simone; Gbobaniyi, Emiola
通讯作者	Yusuf, N
来源期刊	JOURNAL OF AEROSOL SCIENCE
ISSN	0021-8502
EISSN	1879-1964
出版年	2021
卷号	151
英文摘要	The optical properties of aerosols are investigated using multi-year analysis from the Ilorin AERONET site (8.320 N, 4.340 E) in Nigeria, in tropical West Africa. Characterization at five wavelengths (440, 550, 675, 870 and 1020 nm) were carried out to investigate the absorption and scattering tendencies of aerosol properties at multi-timescale. Results show large aerosol optical thickness (AOT) at 550 nm in a mixed aerosol load with 74% coarse mode dominance and 24% fine mode particles densely distributed in the dry-cold/Harmattan season (DJF) and sparsely distributed in the wet season (June-Oct). The volume size distribution (VSD) pattern shows higher variations and dominance for the coarse mode in the dry season than for the accumulation mode. The AngstroEurom exponent (AE) alpha and tau 550 show regular variations, with seasonal averaged maximum alpha > 1 and tau 550 peak at similar to 1.0. Values of alpha > 1 were observed in wet seasons; similar to 1.1 (Aug), 1.04 (Sep). Averaged single scattering albedo (SSA) is confined to values between 0.83 and 0.97, with the highest values in October and lowest values in DJF due to biomass burning (BB) emissions mixed with transported desert dust that are composed of iron oxides (hematite) absorbing mineral. Seasonal omega 0 increases with increasing wavelength and absorption was found to be the highest at 440 nm, with a total absorption of 0.16. The asymmetry parameter g shows minor interannual variations. The highest value of >0.70 was found at the shortest wavelength (440 nm), and was found to decrease as wavelengths increased. The real part of the refractive index (RR) ranges between 1.17 and 1.44 depending on seasons, and the imaginary part of the refractive index (RI) shows higher absorption for dry season (0.009).
英文关键词	Absorption AOT Asymmetry parameter Optical properties Particle size Refractive index SSA Volume size distribution Wavelength
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000591603000004
WOS关键词	SINGLE-SCATTERING ALBEDO ; RADIATIVE PROPERTIES ; CLOUD ; VARIABILITY ; ABSORPTION ; NETWORK ; EUROPE ; DEPTH ; URBAN ; SIZE
WOS类目	Engineering, Chemical ; Engineering, Mechanical ; Environmental Sciences ; Meteorology & Atmospheric Sciences
WOS研究方向	Engineering ; Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/328014
作者单位	[Yusuf, Najib] NASRDA, Ctr Atmospher Res CAR, Anyigba, Kogi State, Nigeria; [Yusuf, Najib; Tilmes, Simone] Natl Ctr Atmospher Res NCAR, Boulder, CO USA; [Yusuf, Najib; Said, Rabia S.] Bayero Univ Kano, Dept Phys, Kano, Nigeria; [Gbobaniyi, Emiola] Swedish Meteorol & Hydrol Inst Norrkoping SMHI, Norrkoping, Sweden
推荐引用方式 GB/T 7714	Yusuf, Najib,Said, Rabia S.,Tilmes, Simone,et al. Multi-year analysis of aerosol optical properties at various timescales using AERONET data in tropical West Africa[J],2021,151.
APA	Yusuf, Najib,Said, Rabia S.,Tilmes, Simone,&Gbobaniyi, Emiola.(2021).Multi-year analysis of aerosol optical properties at various timescales using AERONET data in tropical West Africa.JOURNAL OF AEROSOL SCIENCE,151.
MLA	Yusuf, Najib,et al."Multi-year analysis of aerosol optical properties at various timescales using AERONET data in tropical West Africa".JOURNAL OF AEROSOL SCIENCE 151(2021).