A22C-01 INVITED 

Urban Pollution in the Nocturnal Boundary Layer: Chemical Processing and Vertical Transport

* Stutz, J (jochen@atmos.ucla.edu), University of California Los Angeles, Department of Atmospheric and Oceanic Sciences, Math Sciences 7127, Los Angeles, CA 90095-1565, United States Flynn, C J (connor.flynn@pnl.gov), Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, United States Rappenglück, B (brappenglueck@uh.edu), University of Houston, Department of Geosciences, 4800 Calhoun Rd., Houston, TX 77204-5007, United States Lefer, B (blefer@uh.edu), University of Houston, Department of Geosciences, 4800 Calhoun Rd., Houston, TX 77204-5007, United States Brune, W H (brune@meteo.psu.edu), Penn State University, Department of Meteorology 504 Walker Building, University Park, PA 16802, United States Dibb, J E (jack.dibb@unh.edu), University of New Hampshire, Institute for the Study of Earth, Oceans, and Space, Morse Hall 39 College Road, Durham, NH 03824-3525, United States Griffin, R J (rjg@gust.sr.unh.edu), University of New Hampshire, Institute for the Study of Earth, Oceans, and Space, Morse Hall 39 College Road, Durham, NH 03824-3525, United States

For many decades research on urban pollution and its chemistry has concentrated on processes occurring during the day. In recent years, however, it has become clear that transport and chemical processing at night can also play an important role for urban air quality. Various chemical pathways are known to remove gaseous pollutants, such as nitrogen oxides, ozone and hydrocarbons, as well as influence aerosol composition at night. The quantification of these processes is difficult due to the influence of vertical stability, which leads to a much slower vertical transport of trace gases emitted at the surface at night than during the day. As a consequence, chemistry at night is often very altitude dependent, making investigations in the NBL challenging. In recent years a number of field experiments have been performed where the nocturnal meteorology and the vertical distribution of the dominant trace gases at night have been observed. Here we will review the lessons learned in past studies and present results from a recent study in Houston, TX, which gives new insights into the meteorological and chemical processes at night. The TexAQS II Radical Measurement Project (TRAMP) was performed in August and September 2006, on the University of Houston campus. We will present data from a number of measurements, including a long-path Differential Optical Absorption Spectrometer, in situ instrumentation for gas phase compounds (O₃, NO, NO₂, CO, VOC), HO_x radicals, aerosol size and composition, various meteorological and radiation parameters, and an aerosol LIDAR. The field observations will be compared to 1D model calculations which show the dominant chemical processes and allow the identification of gaps in our understanding of the polluted nocturnal urban boundary layer.

A22C-02 

Observations of High-latitude NOx Removal Processes: The Roles of Dinitrogen Pentoxide, Aerosols, and Seasonal Snow Pack

* Apodaca, R L (ftrla@uaf.edu), Geophysical Institute and Department of Chemistry and Biochemistry University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775, Huff, D M (fsdmh22@uaf.edu), Geophysical Institute and Department of Chemistry and Biochemistry University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775, Cahill, C F (ffcfc@uaf.edu), Geophysical Institute and Department of Chemistry and Biochemistry University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775, Simpson, W R (ffwrs@uaf.edu), Geophysical Institute and Department of Chemistry and Biochemistry University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775,

Heterogeneous chemistry of dinitrogen pentoxide (N₂O₅) plays a major role in the removal of nitrogen oxides (NO_x = NO + NO₂), particularly in the cold, dark nighttime atmosphere in winters at high latitudes. NO_x is ultimately converted to nitric acid, which, in turn, is deposited to surfaces. The resultant nitric acid deposition has unintended consequences, such as nitrogen fertilization and acidification of sensitive ecosystems. As anthropogenic emissions increase globally, and particularly in high latitudes, the importance of a mechanistic understanding of NO_x removal processes and their impact on sensitive ecosystems, becomes more important for assessing fate of this pollution. We report measurements of the sum of NO₃ and N₂O₅ (primarily N₂O₅ at ambient temperatures) in the Fairbanks, AK pollution plume during a two week period in March 2007. Ancillary atmospheric observations include NO, NO₂, and O₃-levels, aerosol particle size distribution, and aerosol elemental composition. N₂O₅ loss to snow pack was observed by measuring boundary layer profiles and chemical composition of the snow. The profiles were conducted by sampling the boundary-layer gradient at 1 and 4 meter altitudes. Results show elevated levels of nitrate ion in the snow pack, typical nighttime lifetimes for N₂O₅ between 10 and 20 minutes, and periods of clear vertical gradients in N₂O₅. The reported lifetimes are short when compared to observations from lower latitudes and most nights demonstrate rapid decay of N₂O₅ prior to sunrise; both phenomena occur in air masses without measurable NO. It is of particular interest that when gradients were present, N₂O₅ mixing ratios typically increased with elevation, but periods were observed where mixing ratios would decrease with elevation. Implications of the short lifetimes, rapid decay of N₂O₅ in highly polluted air masses, and gradient observations are discussed, and suggest that deposition to the surface competed with reactions in the atmosphere during the study. These observations provide a foundation for developing a mechanistic understanding of the NO_x removal pathways at high latitudes.

A22C-03 

Nocturnal processing of O3, NOx & VOC as measured from the NOAA P-3 Aircraft during TexAQS 200

* Brown, S S (steven.s.brown@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Dubé, W P (William.P.dube@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Dubé, W P (William.P.dube@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States Ryerson, T B (thomas.B.Ryerson@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Neuman, J A (andy.Neuman@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Neuman, J A (andy.Neuman@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States Holloway, J S (john.s.holloway@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Holloway, J S (john.s.holloway@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States Warneke, C (carsten.warneke@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Warneke, C (carsten.warneke@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States de Gouw, J A (joost.deGouw@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States de Gouw, J A (joost.deGouw@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States Atlas, E (eatlas@rsmas.miami.edu), University of Miami, RSMAS/MAC 4600 Rickenbacker Causeway, Miami, FL 33149, United States Wollny, A G (adam.wollny@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Wollny, A G (adam.wollny@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States Brock, C A (charles.a.brock@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Bahreini, R (roya.bahreini@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Bahreini, R (roya.bahreini@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, United States Middlebrook, A M (ann.m.Middlebrook@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Trainer, M (michael.k.trainer@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Fehsenfeld, F C (Fred.C.Fehsenfeld@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Meagher, J F (james.f.Meagher@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States Ravishankara, A R (A.R.Ravishankara@noaa.gov), NOAA Earth System Research Laboratory, R/CSD2 325 Broadway, Boulder, CO 80305, United States

The nighttime P-3 flights during TexAQS 2006 were aimed at characterizing the nocturnal reactions, transport and loss of NOx, VOC and O3, with an emphasis on the role of the nighttime nitrogen oxides, NO3 and N2O5. Mixing ratios of NO3 and N2O5 were highly variable and occasionally quite large, consistent with previous aircraft measurements of these compounds. Analysis of these data showed that hydrolysis of N2O5, the most important reaction in the nocturnal conversion of NOx to HNO3, was generally inefficient in air masses around Houston and elsewhere in Texas. As a result, NOx emissions occurring late in the day or at night could be transported overnight in the form of N2O5 to regions distant from the NOx source regions. Transport of O3 was also efficient since N2O5 is a reservoir for odd oxygen (Ox) as well. The reduced rate of N2O5 hydrolysis enhanced the availability of NO3, which is a strong oxidant for highly reactive VOC (HRVOC such as alkenes, some aromatics and oxygenates). This was important in plumes containing both NOx and HRVOC from industrial sources in the Houston area.

A22C-04 

Nighttime Nitrate Radical Chemistry at Appledore Island, Maine during the 2004 International Consortium for Atmospheric Research on Transport and Transformation

* Ambrose, J L (jambrose@unh.edu), Department of Chemistry, University of New Hampshire, Durham, NH 03824, United States * Ambrose, J L (jambrose@unh.edu), Climate Change Research Center, Institute for the Study of Earth Oceans and Space, University of New Hampshire, Durham, NH 03824, United States Mao, H (hmao@gust.sr.unh.edu), Climate Change Research Center, Institute for the Study of Earth Oceans and Space, University of New Hampshire, Durham, NH 03824, United States Mayne, H R (howard.mayne@unh.edu), Department of Chemistry, University of New Hampshire, Durham, NH 03824, United States Stutz, J (jochen@atmos.ucla.edu), Department of Atmospheric Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1565, United States Talbot, R (robert.talbot@unh.edu), Climate Change Research Center, Institute for the Study of Earth Oceans and Space, University of New Hampshire, Durham, NH 03824, United States Sive, B C (bcs@ccrc.sr.unh.edu), Climate Change Research Center, Institute for the Study of Earth Oceans and Space, University of New Hampshire, Durham, NH 03824, United States

Trace gases including nitrogen dioxide (NO₂), nitrate radical (NO₃), ozone (O₃), and a suite of volatile organic compounds (VOCs) were measured within the New England coastal marine boundary layer on Appledore Island (AI), Maine, USA as part of the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) field campaign. These measurements, together with local meteorological records and published kinetic data were used to investigate nighttime NO₃ chemistry at AI during the period of July 8 to 28, 2004. Among the VOCs, isoprene, monoterpenes and dimethylsulfide (DMS) were the dominant NO₃ reactants; on average, DMS accounted for 51 ± 34% of the total reactivity. For three case studies, NO₃ mixing ratios were calculated from measured parameters with resultant uncertainties of <30%. We indirectly determined that nighttime NO₃ and NO_x removal via N₂O₅ chemistry (gas-phase + heterogeneous) was on average 51 to 54% and 63 to 66% of the total respectively. Our analysis suggested that the minimum average NO₃ and NO_x removal via heterogeneous N₂O₅ chemistry was ~10% of the total; however, it is plausible that the latter pathway was often comparable to gas-phase removal of NO₃ and NO_x. Overall, 24 hr-averaged NO_x removal was ~11 ppbv, with nighttime chemical pathways contributing ~50%.

A22C-05 

Radical Chemistry and Ozone Production in the Houston Industrial Area

* Sommariva, R (roberto.sommariva@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States * Sommariva, R (roberto.sommariva@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Brown, S S (Steven.S.Brown@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Roberts, J M (James.M.Roberts@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Roberts, J M (James.M.Roberts@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Parker, A E (aep20@leicester.ac.uk), Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom Brookes, D M (dmb23@leicester.ac.uk), Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom Monks, P S (P.S.Monks@leicester.ac.uk), Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, United Kingdom Osthoff, H D (hosthoff@ucalgary.ca), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Osthoff, H D (hosthoff@ucalgary.ca), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Gilman, J B (Jessica.Gilman@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Gilman, J B (Jessica.Gilman@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Goldan, P D (paul.d.goldan@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Goldan, P D (paul.d.goldan@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Kuster, W C (William.C.Kuster@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Kuster, W C (William.C.Kuster@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Lerner, B M (Brian.Lerner@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Lerner, B M (Brian.Lerner@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Welsh-Bon, D (Daniel.Welshbon@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Welsh-Bon, D (Daniel.Welshbon@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Williams, E J (Eric.J.Williams@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Williams, E J (Eric.J.Williams@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Fehsenfeld, F C (Fred.C.Fehsenfeld@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Fehsenfeld, F C (Fred.C.Fehsenfeld@noaa.gov), Cooperative Institute for Research in Environmental Sciences, University of Colorado- Boulder, 216 UCB, Boulder, CO 80309, United States Ravishankara, A R (A.R.Ravishankara@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States Ravishankara, A R (A.R.Ravishankara@noaa.gov), Department of Chemistry and Biochemistry, University of Colorado-Boulder, 215 UCB, Boulder, CO 80309, United States Trainer, M (Michael.K.Trainer@noaa.gov), Earth System Research Laboratory, National Oceanic and Atmospheric Administration, 325 Broadway, Boulder, CO 80305, United States

Measurements of radicals (HO₂+RO₂, NO₃) were taken on board of the NOAA ship R/V Brown during the Texas Air Quality Study/Gulf of Mexico Atmospheric Composition and Climate Study (TexAQS/GoMACCS) 2006 field campaign. HO₂+RO₂ was measured by Chemical Amplification and NO₃ (with N₂O₅) was measured by Cavity Ring-Down Spectroscopy. The R/V Brown cruised for a month (August-September 2006) off the coast of Texas and inside Galveston Bay and Houston industrial and shipping area, sampling air masses coming from the highly industrialized region of Southern United States. The data collected during the cruise were analyzed using a zero-dimensional box-model based upon the Leeds Master Chemical Mechanism (MCM). The model was constrained to the measurements of long-lived species and physical parameters and used to calculate the concentrations of radicals (OH, HO₂, RO₂, NO₃) during the cruise of the R/V Brown. The modelled concentrations of HO₂+RO₂ and NO₃ were compared with the measurements. The model and the measurements were used to study ozone formation and photochemistry in one of the most polluted areas of the United States.

A22C-06 

Hydroxyl and Hydroperoxy Radical Chemistry during the MCMA-2006 Field Campaign: Measurement and Model Comparison

* Dusanter, S (sdusante@indiana.edu), Center for Research in Environmental Science, School of Public and Environmental Affairs, and Department of Chemistry, Indiana University, Bloomington, IN 47405, Vimal, D), Center for Research in Environmental Science, School of Public and Environmental Affairs, and Department of Chemistry, Indiana University, Bloomington, IN 47405, Stevens, P S), Center for Research in Environmental Science, School of Public and Environmental Affairs, and Department of Chemistry, Indiana University, Bloomington, IN 47405, Volkamer, R), Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309, Molina, L T), Molina Center for Energy and the Environment, 3262 Holiday Ct., La Jolla, CA 92037, Molina, L T), Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139,

The Mexico City Metropolitan Area (MCMA) field campaign, held in March 2006, was a unique opportunity to collect data in one of the most polluted megacities in the world. Such environments exhibit a complex oxidation chemistry involving a strong coupling between odd hydrogen radicals (HO_X=OH+HO₂) and nitrogen oxides species (NO_X=NO+NO₂). High levels of volatile organic compounds (VOCs) and NO_X control the HO_X budget and lead to elevated tropospheric ozone formation. The HO_X-NO_X coupling can be investigated by comparing measured and model-predicted HOx concentrations. Atmospheric HO_X concentrations were measured by the Indiana University laser-induced fluorescence instrument and data were collected at the Instituto Mexicano del Petroleo between 14 and 31 March. Measured hydroxyl radical (OH) concentrations are comparable to that measured in less polluted urban environments and suggest that the OH concentrations are highly buffered under high NO_X conditions. In contrast, hydroperoxy radical (HO₂) concentrations are more sensitive to the NO_X levels and are highly variable between different urban sites. Enhanced levels of OH and HO₂ radicals were observed on several days between 9h30-11h00 AM and suggest an additional HO_X source for the morning hours and/or a fast HO_X cycling under the high NO_X conditions of the MCMA. A preliminary investigation of the HO_X chemistry occurring in the MCMA urban atmosphere was performed using a photochemical box model based on the Regional Atmospheric Chemistry Mechanism (RACM). Model comparisons will be presented and the agreement between measured and predicted HO_X concentrations will be discussed.

A22C-07 

Real time observations of glyoxal by Laser-Induced-Phosphorescence during BEARPEX

* Keutsch, F N (keutsch@wisc.edu), UW Madison, Department of Chemistry, 1101 University Avenue, Madison, WI 53706, United States Huisman, A), UW Madison, Department of Chemistry, 1101 University Avenue, Madison, WI 53706, United States Hottle, J), UW Madison, Department of Chemistry, 1101 University Avenue, Madison, WI 53706, United States Galloway, M), UW Madison, Department of Chemistry, 1101 University Avenue, Madison, WI 53706, United States Coens, K), UW Madison, Department of Chemistry, 1101 University Avenue, Madison, WI 53706, United States DiGangi, J), UW Madison, Department of Chemistry, 1101 University Avenue, Madison, WI 53706, United States

Observations of the diurnal cycle in glyoxal, including nighttime data, with a high sensitivity, fast, direct and highly specific Laser-Induced-Phosphorescence instrument during the BEARPEX campaign at Blodgett Forest in August/September 2007 will be presented. The observed glyoxal concentrations show a pronounced and highly variable diurnal cycle. The relationship of the observed glyoxal concentrations to biogenic and anthropogenic emissions will be discussed.

A22C-08 

SOA Production From Cloud Processing of Glycolaldehyde

* Perri, M J (mperri@rutgers.edu), Department of Environmental Sciences, Rutgers University, 14 College Farm Rd., New Brunswick, NJ 08901, United States * Perri, M J (mperri@rutgers.edu), Institute of Marine and Coastal Sciences, Rutgers University, 71 Dudley Rd., New Brunswick, NJ 08901, Seitzinger, S P (sybil@marine.rutgers.edu), Institute of Marine and Coastal Sciences, Rutgers University, 71 Dudley Rd., New Brunswick, NJ 08901, Seitzinger, S P (sybil@marine.rutgers.edu), Rutgers/NOAA CMER Program, Rutgers University, 71 Dudley Rd., New Brunswick, NJ 08901, United States Tan, Y (ytan@envsci.rutgers.edu), Department of Environmental Sciences, Rutgers University, 14 College Farm Rd., New Brunswick, NJ 08901, United States Turpin, B J (turpin@envsci.rutgers.edu), Department of Environmental Sciences, Rutgers University, 14 College Farm Rd., New Brunswick, NJ 08901, United States

Recent studies suggest that aqueous cloud chemistry contributes to secondary organic aerosol (SOA) production. Gas phase primary precursors, such as ethene and isoprene, can oxidize in the interstitial spaces of clouds to form water-soluble species, including glycolaldehyde. These water-soluble products can partition into cloud droplets and undergo further oxidation (e.g., via hydroxyl radicals). If low-volatility products (e.g., oxalate) are formed, these products can remain in the particle phase following droplet evaporation, forming organic aerosol. Organic aerosol plays an important role in cloud microphysics, visibility, and human health, yet little is known about aqueous phase reaction pathways and products that contribute to SOA. The kinetics of aqueous phase glycolaldehyde oxidation were studied and products were identified. Hydroxyl radical was generated via continuous UV photolysis of hydrogen peroxide inside a glass photochemical vessel. The reaction of glycolaldehyde and hydroxyl radical was monitored in real-time via continuous electrospray ionization mass spectrometry (ESI-MS). Organic products (acids and aldehydes) formed and destroyed during the reaction were identified and quantified via negative and positive mode ionization. Based on ESI-MS data obtained, glycolaldehyde is oxidized via hydroxyl radical to glycolic acid, glyoxylic acid, and ultimately oxalic acid, as previously suggested. In addition, several unexpected higher molecular weight compounds were produced, and identification of these reaction products is currently underway. The results obtained from this study serve to validate and refine the aqueous SOA-producing pathway for glycolaldehyde in cloud chemistry models and can be used to increase the accuracy of SOA prediction in atmospheric air quality and climate models.

Author(s) (2007), Title, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract #####-##.