A13E-01 INVITED 14:40h

Ambient VOC Concentration and Emission Measurements during the MCMA 2002 and 2003 Field Campaigns

* Lamb, B K (blamb@wsu.edu) , Washington State University, Laboratory for Atmospheric Research Dept of Civil & Environmental Engineering, Pullman, WA 99164-2910 United States
Velasco, E , Washington State University, Laboratory for Atmospheric Research Dept of Civil & Environmental Engineering, Pullman, WA 99164-2910 United States
Allwine, E , Washington State University, Laboratory for Atmospheric Research Dept of Civil & Environmental Engineering, Pullman, WA 99164-2910 United States
Pressley, S , Washington State University, Laboratory for Atmospheric Research Dept of Civil & Environmental Engineering, Pullman, WA 99164-2910 United States
Westberg, H , Washington State University, Laboratory for Atmospheric Research Dept of Civil & Environmental Engineering, Pullman, WA 99164-2910 United States
Knighton, B , Montana State University, Department of Chemistry and Biochemistry PO Box 173400 , Bozeman, MT 59717-3400 United States
Rogers, T , Montana State University, Department of Chemistry and Biochemistry PO Box 173400 , Bozeman, MT 59717-3400 United States
Grimsrud, E , Montana State University, Department of Chemistry and Biochemistry PO Box 173400 , Bozeman, MT 59717-3400 United States
Jobson, T , Pacific Northwest National Laboratory, P.O.Box 999, MSIN K9-30 , Richland, WA 99352 United States
Alexander, M , Pacific Northwest National Laboratory, P.O.Box 999, MSIN K9-30 , Richland, WA 99352 United States
Prazeller, P , Pacific Northwest National Laboratory, P.O.Box 999, MSIN K9-30 , Richland, WA 99352 United States
Volkamer, R , Massachusetts Institute of Technology, 77 Massachusetts Av, Cambridge, MA 02139 United States
de Foy, B , Massachusetts Institute of Technology, 77 Massachusetts Av, Cambridge, MA 02139 United States
Molina, L , Massachusetts Institute of Technology, 77 Massachusetts Av, Cambridge, MA 02139 United States
Molina, M , Massachusetts Institute of Technology, 77 Massachusetts Av, Cambridge, MA 02139 United States
Grutter, M , Universidad Nacional Autonoma de Mexico, Centro de Ciencias de la Atmsfera - UNAM Universidad Nacional Autonoma de Mexico Circuito Exterior s/n, Ciudad Universitaria Delegacion Coyoacan, 04510 Mexico D.F , Mexico City, DF 04510 Mexico
Bueno, E , National Center for Environmental Research and Training (CENICA), National Institute of Ecology (INE) Periferico 5000, Col. Insurgentes Cuicuilco, C.P. 04530, Del. Coyoacan, Mexico D.F , Coyoacan, DF 04530 Mexico
Blanco, S , National Center for Environmental Research and Training (CENICA), National Institute of Ecology (INE) Periferico 5000, Col. Insurgentes Cuicuilco, C.P. 04530, Del. Coyoacan, Mexico D.F , Coyoacan, DF 04530 Mexico
Wohrnschimmel, H , National Center for Environmental Research and Training (CENICA), National Institute of Ecology (INE) Periferico 5000, Col. Insurgentes Cuicuilco, C.P. 04530, Del. Coyoacan, Mexico D.F , Coyoacan, DF 04530 Mexico
Cardenas, B , National Center for Environmental Research and Training (CENICA), National Institute of Ecology (INE) Periferico 5000, Col. Insurgentes Cuicuilco, C.P. 04530, Del. Coyoacan, Mexico D.F , Coyoacan, DF 04530 Mexico
Arriaga, J L , Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152 Mexico, D.F. C.P. 07730 Mexico , Mexico City, D.F 07730 Mexico
Limon, M T , Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152 Mexico, D.F. C.P. 07730 Mexico , Mexico City, D.F 07730 Mexico
Escalona, S , Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152 Mexico, D.F. C.P. 07730 Mexico , Mexico City, D.F 07730 Mexico
Iglesias, G S , Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152 Mexico, D.F. C.P. 07730 Mexico , Mexico City, D.F 07730 Mexico
Doskey, P , Argonne National Laboratory, Environmental Research Division Bldg. 203/ER , Argonne, IL 60439 United States
Gaffney, J , Argonne National Laboratory, Environmental Research Division Bldg. 203/ER , Argonne, IL 60439 United States

As part of the MCMA 2002 and 2003 field campaigns in Mexico City, ambient VOC samples were collected from airshed boundary sites, central urban core sites and downwind urban receptor sites. Samples were also obtained during mobile vehicle chase operations designed to obtain data on direct vehicle emissions. During MCMA 2003, additional VOC data were collected including open, long path measurements at the Cenica and La Merced sites, direct eddy covariance flux measurements at Cenica, other canister and cartridge samples collected at La Merced and balloon profiles collected at Cenica. In addition, an automated continuous VOC sampling and analysis system was operated at Cenica. Collectively, the VOC data are consistent with previous measurements that show significantly higher levels of light alkanes compared to US cities. The levels of most other VOCs are also elevated compared to the median for US cities. Examination of the VOC data in terms of lumped VOC classes and suggests that some, but not all, classes are underestimated in the emission inventory by factors of 2 to 3. The use of ratios of individual VOC is useful for examining the effects of chemistry or nearby sources on measured VOC levels. Comparison of PTR-MS results with GC/FID data showed very good agreement for a number of aromatics, and the PTR-MS data for oxygenated VOC suggests that oxygenated VOC contribute an additional 20% to the overall VOC burden. The use of a fast olefin sensor (FOS) for continuous measurement of olefin concentrations was demonstrated, but only half of the FOS signal could be accounted for in terms of olefins identified from canister samples.

A13E-02 INVITED 14:55h

Mexico City's active photochemistry: conclusions from the MCMA-2003 study

* Brune, W (brune@ems.psu.edu) , Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
Shirley, T , Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
Lesher, R , Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
Mao, J , Pennsylvania State University, Department of Meteorology, 503 Walker Building, University Park, PA 16802 United States
Volkamer, R , Maasachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Scineces, 77 Massachusetts Av., Cambidge, MA 02139 United States
Molina, L , Maasachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Scineces, 77 Massachusetts Av., Cambidge, MA 02139 United States
Molina, M , Maasachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Scineces, 77 Massachusetts Av., Cambidge, MA 02139 United States
Velasco, E , Washington State University, Civil and Environmental Engineering, Sloan Hall 101, Spokane Street, Pullman, WA 99164 United States
Westberg, H , Washington State University, Civil and Environmental Engineering, Sloan Hall 101, Spokane Street, Pullman, WA 99164 United States
Lamb, B , Washington State University, Civil and Environmental Engineering, Sloan Hall 101, Spokane Street, Pullman, WA 99164 United States
Jobson, T , Pacific Northwest National Laboratory, P.O. Box 999, MSIN K9-30, Richland, WA 99352 United States
Alexander, M , Pacific Northwest National Laboratory, P.O. Box 999, MSIN K9-30, Richland, WA 99352 United States
Gonzalez, B C , General Direction of the National Center for Environmental Research and Training (CENICA) - National Institute of Ecology (INE), Periferico 5000, Col. Insurgentes Cuicuilco, Delegacion Coyoacan, D.F 04530 Mexico

Mexico City Metropolitan Area's active photochemistry was studied using an extensive suite of measurements on the CENICA environmental laboratory's roof, as part of the MCMA-2003 field study. Intense morning sunlight photolyzed HONO and HCHO, producing hydrogen oxides (OH and HO$_2$) at high rates. The HO$_x$ interacted with rush-hour volatile organic compounds (VOCs) and nitrogen oxides (NO$_x$), amplifying the production rate of ozone and nitric acid. With typically 100 ppbv of NO$_x$ and 1 ppmC of VOCs, ozone production rates exceeded 30 ppbv/hour, routinely creating in excess of 150 ppbv of ozone, even though the midday mixed layer was more than 3 km deep. Analyses of glyoxal, a product of VOC oxidation, and the hydroperoxyl radical (HO$_2$) indicate that MCMA's ozone production was VOC-limited during morning rush hour, when typically of the ozone is produced, and for a significant number of days during midday and afternoon at the site. Aspects of Mexico City's active photochemistry will be compared to the observed photochemistry in U.S. urban areas.

A13E-03 INVITED 15:10h

Overview of Measurements of Particle Emissions and Ambient Concentrations in Mexico City during the MCMA-2003 Field Campaign

* Jimenez, J L (jose.jimenez@colorado.edu) , Univ. of Colorado, UCB 216, Boulder, CO 80309 United States
Dzepina, K (katja.dzepina@colorado.edu) , Univ. of Colorado, UCB 216, Boulder, CO 80309 United States
Zhang, Q (zhangq@cires.colorado.edu) , Univ. of Colorado, UCB 216, Boulder, CO 80309 United States
Dunn, M (matthew.dunn@colorado.edu) , Univ. of Colorado, UCB 216, Boulder, CO 80309 United States
DeCarlo, P (peter.decarlo@colorado.edu) , Univ. of Colorado, UCB 216, Boulder, CO 80309 United States
Huffman, J (alex.huffman@colorado.edu) , Univ. of Colorado, UCB 216, Boulder, CO 80309 United States
Salcedo, D (dara@ciq.uaem.mx) , Univ. de Morelos, Av. Universidad 1001, Cuernavaca, 62210 Mexico
Onasch, T (onasch@aerodyne.com) , Aerodyne Research, Inc., 45 Manning Rd, Billerica, MA 01821 United States
Worsnop, D R (worsnop@aerodyne.com) , Aerodyne Research, Inc., 45 Manning Rd, Billerica, MA 01821 United States
Kolb, C E (kolb@aerodyne.com) , Aerodyne Research, Inc., 45 Manning Rd, Billerica, MA 01821 United States
Mortimer, P (mortimer@aerodyne.com) , Aerodyne Research, Inc., 45 Manning Rd, Billerica, MA 01821 United States
Jayne, J T (jayne@aerodyne.com) , Aerodyne Research, Inc., 45 Manning Rd, Billerica, MA 01821 United States
Canagaratna, M R (mrcana@aerodyne.com) , Aerodyne Research, Inc., 45 Manning Rd, Billerica, MA 01821 United States
Volkamer, R (rainer@mit.edu) , MIT, 77, Mass. Ave., Cambridge, MA 02139 United States
Johnsson, K (kirstenj@MIT.EDU) , MIT, 77, Mass. Ave., Cambridge, MA 02139 United States
Zuberi, B (bzuberi@geo2tech.com) , MIT, 77, Mass. Ave., Cambridge, MA 02139 United States
de Foy, B (foy@MIT.EDU) , MIT, 77, Mass. Ave., Cambridge, MA 02139 United States
Frey, S (lidar@mit.edu) , MIT, 77, Mass. Ave., Cambridge, MA 02139 United States
Molina, M (mmolina@mit.edu) , MIT, 77, Mass. Ave., Cambridge, MA 02139 United States
Molina, L T (ltmolina@mit.edu) , MIT, 77, Mass. Ave., Cambridge, MA 02139 United States
Marr, L (lmarr@vt.edu) , Virginia Tech, 411 Durham Hall, Blacksburg, VA 24061 United States
Arey, J (janet.Arey@ucr.edu) , Univ. California, Riverside, 900 Univ. Ave, Riverside, CA 92521 United States
Cardenas, B (bcar@xanum.uam.mx) , CENICA, Periferico 5000, Mexico City, 04530 Mexico
Brune, W H (brune@essc.psu.edu) , Penn. State Univ., 503 Walker Bldg., University Park, PA 16802 United States
Smith, J (jimsmith@ucar.edu) , NCAR, 1850 Table Mesa, Boulder, CO 80305 United States
McMurry, P (mcmurry@me.umn.edu) , U. of Minn., 111 Church St. SE, Minneapolis, MN 55455 United States
Gaffney, J (gaffney@anl.gov) , Argonne Nat. Lab, 203/ER, Argonne, IL 60439 United States
Marley, N (marley@anl.gov) , Argonne Nat. Lab, 203/ER, Argonne, IL 60439 United States
Laskin, A (alexander.laskin@pnl.gov) , PNNL, P.O.Box 999, Richland, WA 99352 United States
Cowin, J (james.cowin@pnl.gov) , PNNL, P.O.Box 999, Richland, WA 99352 United States
Bernabe, R (rbernabe@ine.gob.mx) , CENICA, Periferico 5000, Mexico City, 04530 Mexico
Blanco, S (sblanco@ine.gob.mx) , CENICA, Periferico 5000, Mexico City, 04530 Mexico
Marquez, C (c_marqueze@hotmail.com) , CENICA, Periferico 5000, Mexico City, 04530 Mexico
Angeles, F (fangeles@chajul.ine.gob.mx) , CENICA, Periferico 5000, Mexico City, 04530 Mexico

We will summarize the particle emission rates and concentrations measured in Mexico City during the MCMA-2003 field campaign (3/29-5/5), which will be detailed in additional presentations. Ambient concentration measurements were carried out continuously at the CENICA Supersite inside the city, and at several other fixed locations using the Aerodyne Mobile Laboratory (ML). CENICA was equipped with an Aerosol Mass Spectrometer (AMS), an aethalometer, a PM2.5 TEOM, a TSI DustTrack, a Lasair OPC, a nano-SMPS, a particle PAH detector, and samplers for off-line microscopy (CCSEM-EDX, TEM), composition analysis (TOF-SIMS, PIXE/PESA, and STEM), and PAH analysis. The ML was equipped with AMS, a CPC, an aethalometer, a DustTrack, and a PAH detector. Particle precursors were also measured by a number of groups. The submicron aerosol was dominated by organics, with a smaller contributions of inorganic species, black carbon, dust & metals. Both mixing layer dynamics and horizontal advection play important roles in the measured concentrations. We used a new procedure (Zhang et al. this conf.) to estimate the organic that is primary/combustion (~1/3) vs. oxygenated/secondary (~2/3). Intense secondary aerosol formation was observed, consistent with the high levels of aerosol precursors, radiation, and radicals (OH, HO2). During the Holy Weekend vacation period concentrations were lower but the mix of species was similar. We observed two main sources of ultrafine particles in the city: sulfate-dominated new particle formation, and traffic emissions. Other locations in the city had similar particle concentrations and dynamics as at CENICA, while a boundary site had significantly lower concentrations except when advection brought city air. PAH measurements will be briefly reviewed. Freshly-emitted soot is rapidly processed, leading to the presence of inorganic species such as ammonium sulfate on the soot surface. The ML was used to characterize on-road aerosol emissions from mixed traffic and from individual vehicles in "chase mode". Other mobile point and area aerosol emission sources were also characterized by the ML as it mapped the pollutant concentrations within the city. Examples include elevated NH3 observed in areas with open sewer systems and large spikes in aerosol Cl- seen during refuse burning events.

http://eaps.mit.edu/megacities/

A13E-04 INVITED 15:25h

Policy Implications of Air Quality Research

* Sheinbaum, C (csheinbaum@sma.df.gob.mx) , Secretary of Environment, Government of the Federal District, Plaza de la Constitucion No. 1, Piso 3, Col. Centro Historico, Del. Cuauhtemoc, Mexico City, 06068 Mexico

While an integrated assessment approach will be required to achieve and sustain improvements in the air quality of Mexico City Metropolitan Area's (MCMA), policy strategies must be based on a solid understanding of the pollutant emissions and atmospheric processes that lead to unacceptable levels of air pollution. The required level of understanding can only be achieved by comprehensive atmospheric measurements followed by a coordinated atmospheric modeling program. The innovative, two-phase atmospheric measurement program, which was a collaborative effort between Massachusetts Institute of Technology and the Mexican Metropolitan Environmental Commission, with exploratory measurements in February 2002 and extensive measurements from late March through early May of 2003, was an important step towards meeting these requirements. Although the extensive data sets from the two measurement programs are still being analyzed by the investigators, their preliminary analysis efforts have yielded important insights into the nature and extent of air pollution problem in the MCMA, which in turn will have important policy implications.

Author(s) (2004), Title, Eos Trans. AGU, 85(47), Fall Meet. Suppl., Abstract #####-##.