DOI: 10.1002/jgrd.50165
论文题名: Aerosol climatology at Delhi in the western Indo-Gangetic Plain: Microphysics, long-term trends, and source strengths
作者: Lodhi N.K. ; Beegum S.N. ; Singh S. ; Kumar K.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 3 起始页码: 1361
结束页码: 1375
语种: 英语
英文关键词: aerosol climatology
; aerosol optical depth
; concentration weighted trajectory analysis
; long-term trend
Scopus关键词: Air quality
; Atmospheric aerosols
; Atmospheric thermodynamics
; Physics
; Sea level
; Trajectories
; Aerosol optical depths
; Aerosol size distributions
; Air mass back trajectories
; Ground based measurement
; Indo-Gangetic Plains
; Long-term measurements
; Long-term trend
; Trajectory analysis
; Climatology
; advection
; aerosol
; air mass
; annual variation
; atmospheric pollution
; climatology
; optical depth
; seasonal variation
; size distribution
; statistical analysis
; trajectory
; wavelength
; Delhi
; Gangetic Plain
; India
英文摘要: We present the climatology of aerosol microphysics, its trends, and impact of potential sources based on the long term measurements (for a period of 11.5 years from December 2001 to May 2012) of aerosol optical depths (AOD) in the spectral range 340-1020 nm from an urban center Delhi (28.6°N, 77.3°E, 238 m mean sea level) in the western Indo-Gangetic Plain (IGP). The study is the first ever long-term characterization of aerosols over the western IGP from the ground-based measurements. AODs are known to affect the air quality, visibility, radiative balance, and cloud microphysics of the region and IGP is one of the highest populated and polluted regions of the world. Our measurements show consistently high AOD during the entire period of observation. The seasonal variations of spectral AODs and Angstrom parameters are generally consistent every year. The AODs show a weak but statistically significant (in 95% confidence level) decreasing trend approximately -0.02/year at 500 nm, possibly, modulated by the pre-monsoon heavy dust loading during the first half of the observation period. The climatological monthly mean AOD at shorter wavelengths peaks twice, during June and November, while at longer wavelengths it shows only one peak in June. The annual variations of Angstrom exponent, α and its derivative, α′ suggest the prevalence of multi-modal aerosol size distributions at Delhi. The coarse-mode aerosols dominate during summer (March-June) and monsoon (July-September) seasons, whereas fine/accumulation mode enhances during post-monsoon (October-November) and winter (December-February) seasons. Potential advection pathways have been identified using concentration weighted trajectory (CWT) analysis of the 5 day isentropic air mass back trajectories at the observation site and their seasonal variations are discussed. ©2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63957
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Radio and Atmospheric Sciences Division, National Physical Laboratory, CSIR, New Delhi-110012, India; School of Environmental Science, Jawaharlal Nehru University, New Delhi, India
Recommended Citation:
Lodhi N.K.,Beegum S.N.,Singh S.,et al. Aerosol climatology at Delhi in the western Indo-Gangetic Plain: Microphysics, long-term trends, and source strengths[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(3)