DOI: 10.1016/j.atmosenv.2017.10.035
Scopus记录号: 2-s2.0-85032287388
论文题名: Strong influence of deposition and vertical mixing on secondary organic aerosol concentrations in CMAQ and CAMx
作者: Shu Q ; , Koo B ; , Yarwood G ; , Henderson B ; H
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 171 起始页码: 317
结束页码: 329
语种: 英语
英文关键词: CAMx
; CMAQ
; Deposition
; Model bias
; SOA
; Vertical mixing
; Volatility basis set
Scopus关键词: Aerosols
; Air quality
; Carbon
; Chemical analysis
; Mixing
; Uncertainty analysis
; Volatile organic compounds
; Basis sets
; CAMx
; CMAQ
; Model bias
; Vertical mixing
; Deposition
; volatile organic compound
; aerosol
; air quality
; atmospheric modeling
; concentration (composition)
; deposition velocity
; elemental carbon
; vertical mixing
; volatile organic compound
; air quality
; Article
; atmospheric deposition
; boundary layer
; circadian rhythm
; dry deposition
; priority journal
; secondary organic aerosol
; summer
; United States
; wet deposition
; United States
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: Differences between two air quality modeling systems reveal important uncertainties in model representations of secondary organic aerosol (SOA) fate. Two commonly applied models (CMAQ: Community Multiscale Air Quality; CAMx: Comprehensive Air Quality Model with extensions) predict very different OA concentrations over the eastern U.S., even when using the same source data for emissions and meteorology and the same SOA modeling approach. Both models include an option to output a detailed accounting of how each model process (e.g., chemistry, deposition, etc.) alters the mass of each modeled species, referred to as process analysis. We therefore perform a detailed diagnostic evaluation to quantify simulated tendencies (Gg/hr) of each modeled process affecting both the total model burden (Gg) of semi-volatile organic compounds (SVOC) in the gas (g) and aerosol (a) phases and the vertical structures to identify causes of concentration differences between the two models. Large differences in deposition (CMAQ: 69.2 Gg/d; CAMx: 46.5 Gg/d) contribute to significant OA bias in CMAQ relative to daily averaged ambient concentration measurements. CMAQ's larger deposition results from faster daily average deposition velocities (VD) for both SVOC (g) (VD,cmaq = 2.15 × VD,camx) and aerosols (VD,cmaq = 4.43 × Vd,camx). Higher aerosol deposition velocity would be expected to cause similar biases for inert compounds like elemental carbon (EC), but this was not seen. Daytime low-biases in EC were also simulated in CMAQ as expected but were offset by nighttime high-biases. Nighttime high-biases were a result of overly shallow mixing in CMAQ leading to a higher fraction of EC total atmospheric mass in the first layer (CAMx: 5.1–6.4%; CMAQ: 5.6–6.9%). Because of the opposing daytime and nighttime biases, the apparent daily average bias for EC is reduced. For OA, there are two effects of reduced vertical mixing: SOA and SVOC are concentrated near the surface, but SOA yields are reduced near the surface by nighttime enhancement of NOx. These results help to characterize model processes in the context of SOA and provide guidance for model improvement. © 2017 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/82159
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: University of Florida, Engineering School of Sustainable Infrastructure and Environment, United States; Ramboll Environ, Novato, CA, United States
Recommended Citation:
Shu Q,, Koo B,, Yarwood G,et al. Strong influence of deposition and vertical mixing on secondary organic aerosol concentrations in CMAQ and CAMx[J]. Atmospheric Environment,2017-01-01,171