DOI: 10.1016/j.atmosenv.2015.10.001
Scopus记录号: 2-s2.0-84944066560
论文题名: Molecular view modeling of atmospheric organic particulate matter: Incorporating molecular structure and co-condensation of water
作者: Pankow J ; F ; , Marks M ; C ; , Barsanti K ; C ; , Mahmud A ; , Asher W ; E ; , Li J ; , Ying Q ; , Jathar S ; H ; , Kleeman M ; J
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 122 起始页码: 400
结束页码: 408
语种: 英语
英文关键词: Absorption model
; Co-condensation of water
; OA
; OPM
; Organic aerosol
; Organic particulate matter
; RH effects
; Secondary organic aerosol
; SOA
; Water
Scopus关键词: Aerosols
; Atmospheric chemistry
; Atmospheric humidity
; Atmospheric movements
; Atmospheric structure
; Carbon
; Condensation
; Iterative methods
; Optical properties
; Organic compounds
; Rhodium compounds
; Salts
; Solubility
; Water
; Water levels
; Absorption model
; Co-condensation
; OA
; OPM
; Organic aerosol
; Organic particulate matters
; Secondary organic aerosols
; SOA
; Water absorption
; organic compound
; water
; absorption
; atmospheric modeling
; condensation
; efficiency measurement
; hydrolysis
; immiscibility
; molecular analysis
; optical property
; particulate organic matter
; relative humidity
; spatiotemporal analysis
; view
; viscosity
; water
; aerosol
; Article
; chemical structure
; elimination reaction
; gas
; humidity
; hydrolysis
; hydrophilicity
; oxidation
; particulate matter
; polymerization
; priority journal
; secondary organic aerosol
; United States
; vapor pressure
; viscosity
; water transport
; Alabama
; Georgia
; Louisiana
; North Carolina
; United States
; Poa
; Tamu
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: Most urban and regional models used to predict levels of organic particulate matter (OPM) are based on fundamental equations for gas/particle partitioning, but make the highly simplifying, anonymized-view (AV) assumptions that OPM levels are not affected by either: a) the molecular characteristics of the condensing organic compounds (other than simple volatility); or b) co-condensation of water as driven by non-zero relative humidity (RH) values. The simplifying assumptions have allowed parameterized chamber results for formation of secondary organic aerosol (SOA) (e.g., "two-product" (2p) coefficients) to be incorporated in chemical transport models. However, a return towards a less simplistic (and more computationally demanding) molecular view (MV) is needed that acknowledges that atmospheric OPM is a mixture of organic compounds with differing polarities, water, and in some cases dissolved salts. The higher computational cost of MV modeling results from a need for iterative calculations of the composition-dependent gas/particle partition coefficient values. MV modeling of OPM that considered water uptake (but not dissolved salts) was carried out for the southeast United States for the period August 29 through September 7, 2006. Three model variants were used at three universities: CMAQ-RH-2p (at PSU), UCD/CIT-RH-2p (at UCD), and CMAQ-RH-MCM (at TAMU). With the first two, MV structural characteristics (carbon number and numbers of functional groups) were assigned to each of the 2p products used in CMAQv.4.7.1 such that resulting predicted Kp,i values matched those in CMAQv.4.7.1. When water uptake was allowed, most runs assumed that uptake occurred only into the SOA portion, and imposed immiscibility of SOA with primary organic aerosol (POA). (POA is often viewed as rather non-polar, while SOA is commonly viewed as moderately-to-rather polar. Some runs with UCD/CIT-RH-2p were used to investigate the effects of POA/SOA miscibility.) CMAQ-RH-MCM used MCM to generate oxidation products, and assumed miscibility of SOA and POA. In a ~500 km wide band from Louisiana through to at least North Carolina, CMAQ-RH-2p and UCD/CIT-RH-2p predicted that water uptake can increase SOA levels by as much as 50-100% (from a range of ~1-2 μg m-3 to a range of ~1-4 μg m-3). CMAQ-RH-MCM predicted much lower effects of water uptake on SOA levels (<10% increase). The results from CMAQ-RH-2p and UCD/CIT-RH-2p are considered more reflective of reality. In the Alabama/Georgia hotspot, both CMAQ-RH-2p and UCD/CIT-RH-2p predicted aerosol water levels that are up to nearly half the predicted SOA levels, namely ~0.5-2 μg m-3. Such water levels in SOA will affect particle optical properties, viscosity, gas/particle partitioning times, and rates of hydrolysis and water elimination reactions. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/81433
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Chemistry, Portland State University, Portland, OR, United States; Department of Civil and Environmental Engineering, Portland State University, Portland, OR, United States; Department of Civil Engineering, Texas A and M University, College Station, TX, United States; Civil and Environmental Engineering, University of California, Davis, CA, United States
Recommended Citation:
Pankow J,F,, Marks M,et al. Molecular view modeling of atmospheric organic particulate matter: Incorporating molecular structure and co-condensation of water[J]. Atmospheric Environment,2015-01-01,122