Chemical evolution of volatile organic compounds in the outflow of the Mexico City Metropolitan area

被引：104

作者：

Apel, E. C. ^{[1
]}

Emmons, L. K. ^{[1
]}

Karl, T. ^{[1
]}

Flocke, F. ^{[1
]}

Hills, A. J. ^{[1
]}

Madronich, S. ^{[1
]}

Lee-Taylor, J. ^{[1
]}

Fried, A. ^{[1
]}

Weibring, P. ^{[1
]}

Walega, J. ^{[1
]}

Richter, D. ^{[1
]}

Tie, X. ^{[1
]}

Mauldin, L. ^{[1
]}

Campos, T. ^{[1
]}

Weinheimer, A. ^{[1
]}

Knapp, D. ^{[1
]}

Sive, B. ^{[2
]}

Kleinman, L. ^{[3
]}

Springston, S. ^{[3
]}

Zaveri, R. ^{[4
]}

Ortega, J. ^{[4
]}

Voss, P. ^{[5
,6
]}

Blake, D. ^{[7
]}

Baker, A. ^{[7
]}

Warneke, C. ^{[8
]}

Welsh-Bon, D. ^{[8
]}

de Gouw, J. ^{[8
]}

Zheng, J. ^{[9
]}

Zhang, R. ^{[9
]}

Rudolph, J. ^{[10
]}

Junkermann, W. ^{[11
]}

Riemer, D. D. ^{[12
]}

机构：

[1] Natl Ctr Atmospher Res, Boulder, CO 80307 USA

[2] Univ New Hampshire, Durham, NH 03824 USA

[3] Brookhaven Natl Lab, Upton, NY 11973 USA

[4] Pacific NW Natl Lab, Richland, WA 99352 USA

[5] Smith Coll, Amherst, MA USA

[6] Univ Massachusetts, Amherst, MA 01003 USA

[7] Univ Calif Irvine, Irvine, CA USA

[8] Natl Ocean & Atmospher Adm, Boulder, CO USA

[9] Texas A&M, Dept Atmospher Sci, College Stn, TX USA

[10] York Univ, Toronto, ON M3J 2R7, Canada

[11] Res Ctr Karlsruhe, Inst Meteorol & Climate Res, IMK IFU, Garmisch Partenkirchen, Germany

[12] Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA

来源：

ATMOSPHERIC CHEMISTRY AND PHYSICS | 2010年 / 10卷 / 05期

基金：

美国国家科学基金会;

关键词：

PROTON-TRANSFER-REACTION; INTERCOMPARISON EXPERIMENT NOMHICE; CHARACTERIZING OZONE PRODUCTION; MASS-SPECTROMETRY; AIR-QUALITY; FORMALDEHYDE MEASUREMENTS; HYDROCARBON RATIOS; EMISSIONS; MODEL; URBAN;

D O I：

10.5194/acp-10-2353-2010

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

The volatile organic compound (VOC) distribution in the Mexico City Metropolitan Area (MCMA) and its evolution as it is uplifted and transported out of the MCMA basin was studied during the 2006 MILAGRO/MIRAGE-Mex field campaign. The results show that in the morning hours in the city center, the VOC distribution is dominated by non-methane hydrocarbons (NMHCs) but with a substantial contribution from oxygenated volatile organic compounds (OVOCs), predominantly from primary emissions. Alkanes account for a large part of the NMHC distribution in terms of mixing ratios. In terms of reactivity, NMHCs also dominate overall, especially in the morning hours. However, in the afternoon, as the boundary layer lifts and air is mixed and aged within the basin, the distribution changes as secondary products are formed. The WRF-Chem (Weather Research and Forecasting with Chemistry) model and MOZART (Model for Ozone and Related chemical Tracers) were able to approximate the observed MCMA daytime patterns and absolute values of the VOC OH reactivity. The MOZART model is also in agreement with observations showing that NMHCs dominate the reactivity distribution except in the afternoon hours. The WRF-Chem and MOZART models showed higher reactivity than the experimental data during the nighttime cycle, perhaps indicating problems with the modeled nighttime boundary layer height. A northeast transport event was studied in which air originating in the MCMA was intercepted aloft with the Department of Energy (DOE) G1 on 18 March and downwind with the National Center for Atmospheric Research (NCAR) C130 one day later on 19 March. A number of identical species measured aboard each aircraft gave insight into the chemical evolution of the plume as it aged and was transported as far as 1000 km downwind; ozone was shown to be photochemically produced in the plume. The WRF-Chem and MOZART models were used to examine the spatial extent and temporal evolution of the plume and to help interpret the observed OH reactivity. The model results generally showed good agreement with experimental results for the total VOC OH reactivity downwind and gave insight into the distributions of VOC chemical classes. A box model with detailed gas phase chemistry (NCAR Master Mechanism), initialized with concentrations observed at one of the ground sites in the MCMA, was used to examine the expected evolution of specific VOCs over a 1-2 day period. The models clearly supported the experimental evidence for NMHC oxidation leading to the formation of OVOCs downwind, which then become the primary fuel for ozone production far away from the MCMA.

引用

页码：2353 / 2375

页数：23

共 83 条

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