Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 2 2009 10.5194/acpd-9-9399-2009 http://www.atmos-chem-phys-discuss.net/9/9399/2009/ http://www.atmos-chem-phys-discuss.net/9/9399/2009/acpd-9-9399-2009.html http://www.atmos-chem-phys-discuss.net/9/9399/2009/acpd-9-9399-2009.pdf 9399 9456 2009-04-09 Aerosol composition of the tropical upper troposphere K. D. Froyd karl.froyd@noaa.gov D. M. Murphy T. J. Sanford D. S. Thomson J. C. Wilson L. Pfister L. Lait NOAA Earth System Research Laboratory, Chemical Sciences Division, Boulder, CO, USA Cooperative Inst. for Res. in Environ. Science, University of Colorado, Boulder, CO, USA Dept.~of Mechanical and Materials Engineering, University of Denver, Denver, CO, USA NASA Ames Research Center, Moffett Field, CA, USA Goddard Earth Sciences and Technology Center, University of Maryland Baltimore County, Baltimore, MD, USA Aerosol composition was measured by the NOAA single particle mass spectrometer (PALMS) aboard the NASA WB-57 high altitude aircraft platform during two Aura Validation Experiment (AVE) campaigns based in Costa Rica in 2004 and 2006. These studies yielded the most complete set of aerosol composition measurements to date throughout the tropical tropopause layer (TTL) and tropical lower stratosphere. We describe the aerosol properties of the tropical atmosphere and use composition tracers to examine particle sources, the role of recent convection, and cirrus-forming potential in the TTL. Tropical dynamics and regional air sources played principal roles in dictating tropospheric aerosol properties. There was a sharp change in aerosol chemical composition at about 12 km altitude coincident with a change in convective influence. Below this level, maritime convection lofted condensable material that generated acidic, sulfate-rich aerosol. These particles contained significant amounts of methanesulfonic acid (MSA) and showed evidence of cloud processes. In contrast, continental convection injected particles and precursors directly into the TTL, yielding a population of neutralized, organic-rich aerosol. The organics were often highly oxidized and particles with oxidized organics also contained nitrate. Above the tropopause, chemical composition gradually changed toward sulfuric acid particles but neutralized particles were still abundant 2 km above the tropopause. Deep continental convection, though sporadic and geographically localized, may strongly influence TTL aerosol properties on a global scale. The abundance of organic-rich aerosol may inhibit ice nucleation and formation of tropopause level cirrus. Abbatt,~J P D., Benz,~S., Cziczo,~D J., Kanji,~Z., Lohmann,~U., and Möhler,~O.: Solid ammonium sulfate aerosols as ice nuclei: A~pathway for cirrus cloud formation, Science, 313, 1770–1773, 2006. Alcala,~C M. and Dessler,~A E.: Observations of deep convection in the tropics using the Tropical Rainfall Measuring Mission (TRMM) precipitation radar, J. Geophys. Res.-Atmos., 107, 4792, doi:10.1029/2002JD002457, 2002. Archuleta,~C M., DeMott,~P J., and Kreidenweis,~S M.: Ice nucleation by surrogates for atmospheric mineral dust and mineral dust/sulfate particles at cirrus temperatures, Atmos. Chem. Phys., 5, 2617–2634, 2005. Atkinson, R., Baulch, D. L., Cox, R. A., Crowley, J. N., Hampson, R. F., Hynes, R. G., Jenkin, M. E., Rossi, M. J., Troe, J., and IUPAC Subcommittee: Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II - gas phase reactions of organic species, Atmos. Chem. Phys., 6, 3625–4055, 2006. Bigg,~E K.: Ammonium compounds in stratospheric aerosols, Tellus, 38B, 62–66, 1986. Blake,~N J., Blake,~D R., Simpson,~I J., Meinardi,~S., Swanson,~A L., Lopez,~J P., Katzenstein,~A S., Barletta,~B., Shirai,~T., Atlas,~E., Sachse,~G., Avery,~M., Vay,~S., Fuelberg,~H E., Kiley,~C M., Kita,~K., and Rowland,~F S.: NMHCs and halocarbons in Asian continental outflow during the Transport and Chemical Evolution over the Pacific (TRACE-P) Field Campaign: Comparison with PEM-West B, J. Geophys. Res.-Atmos., 108, 8806, doi:10.1029/2002JD003367, 2003a. Blake,~N J., Blake,~D R., Swanson,~A L., Atlas,~E., Flocke,~F., and Rowland,~F S.: Latitudinal, vertical, and seasonal variations of C-1-C-4 alkyl nitrates in the troposphere over the Pacific Ocean during PEM-Tropics A~and B: Oceanic and continental sources, J. Geophys. Res.-Atmos., 108, 8242, doi:10.1029/2001JD001444, 2003b. Brock,~C A., Hamill,~P., Wilson,~J C., Jonsson,~H H., and Chan,~K R.: Particle formation in the upper tropical troposphere – a~source of nuclei for the stratospheric aerosol, Science, 270, 1650–1653, 1995. Brock,~C A., Schroder,~F., Karcher,~B., Petzold,~A., Busen,~R., and Fiebig,~M.: Ultrafine particle size distributions measured in aircraft exhaust plumes, J. Geophys. Res.-Atmos., 105, 26555–26567, 2000. Brock,~C A., Hudson,~P K., Lovejoy,~E R., Sullivan,~A., Nowak,~J B., Huey,~L G., Cooper,~O R., Cziczo,~D J., de Gouw,~J., Fehsenfeld,~F C., Holloway,~J S., Hubler,~G., Lafleur,~B G., Murphy,~D M., Neuman,~J A., Nicks,~D K., Orsini,~D A., Parrish,~D D., Ryerson,~T B., Tanner,~D J., Warneke,~C., Weber,~R J., and Wilson,~J C.: Particle characteristics following cloud-modified transport from Asia to North America, J. Geophys. Res.-Atmos., 109, D23S26, doi:10.1029/2003JD004198, 2004. Burgess,~A B., Dudhia,~A., Grainger,~R G., and Stevenson,~D.: Progress in tropospheric ammonia retrieval from the MIPAS satellite instrument, Adv. Space. Res., 37, 2218–2221, 2006. Claeys,~M., Graham,~B., Vas,~G., Wang,~W., Vermeylen,~R., Pashynska,~V., Cafmeyer,~J., Guyon,~P., Andreae,~M O., Artaxo,~P., and Maenhaut,~W.: Formation of secondary organic aerosols through photooxidation of isoprene, Science, 303, 1173–1176, 2004. Cziczo,~D J., DeMott,~P J., Brooks,~S D., Prenni,~A J., Thomson,~D S., Baumgardner,~D., Wilson,~J C., Kreidenweis,~S M., and Murphy,~D M.: Observations of organic species and atmospheric ice formation, Geophys. Res. Lett., 31, L12116, doi:10.1029/2004GL019822, 2004a. Cziczo,~D J., Murphy,~D M., Hudson,~P K., and Thomson,~D S.: Single particle measurements of the chemical composition of cirrus ice residue during CRYSTAL-FACE, J. Geophys. Res.-Atmos., 109, D04201, doi:10.1029/2003JD004032, 2004b. Danielsen,~E F.: Insitu evidence of rapid, vertical, irreversible transport of lower tropospheric air into the lower tropical stratosphere by convective cloud turrets and by larger-scale upwelling in tropical cyclones, J. Geophys. Res.-Atmos., 98, 8665–8681, 1993. Davis,~D., Chen,~G., Bandy,~A., Thornton,~D., Eisele,~F., Mauldin,~L., Tanner,~D., Lenschow,~D., Fuelberg,~H., Huebert,~B., Heath,~J., Clarke,~A., and Blake,~D.: Dimethyl sulfide oxidation in the equatorial Pacific: Comparison of model simulations with field observations for DMS, \chemSO_2, \chemH_2SO_4(g), MSA(g), MS, and NSS, J. Geophys. Res.-Atmos., 104, 5765–5784, 1999. DeMore,~W B.: Chemical kinetics and photochemical data for use in stratospheric modeling evaluation number 15, National Aeronautics and Space Administration Jet Propulsion Laboratory, http://jpldataeval.jpl.nasa.gov/, 2006. DeMott,~P J., Cziczo,~D J., Prenni,~A J., Murphy,~D M., Kreidenweis,~S M., Thomson,~D S., Borys,~R., and Rogers,~D C.: Measurements of the concentration and composition of nuclei for cirrus formation, P. Natl. Acad. Sci. USA, 100, 14655–14660, 2003. Dentener,~F J. and Crutzen,~P J.: A~3-dimensional model of the global ammonia cycle, J. Atmos. Chem., 19, 331–369, 1994. Dessler,~A E. and Yang,~P.: The distribution of tropical thin cirrus clouds inferred from terra MODIS data, J. Climate., 16, 1241–1247, 2003. Dessler,~A E., Palm,~S P., Hart,~W D., and Spinhirne,~J D.: Tropopause-level thin cirrus coverage revealed by ICESat/geoscience laser altimeter system, J. Geophys. Res.-Atmos., 111, D08203, doi:10.1029/2005JD006586, 2006. Dibb,~J E., Talbot,~R W., Scheuer,~E M., Blake,~D R., Blake,~N J., Gregory,~G L., Sachse,~G W., and Thornton,~D C.: Aerosol chemical composition and distribution during the Pacific Exploratory Mission (PEM) tropics, J. Geophys. Res.-Atmos., 104, 5785–5800, 1999. Dibb,~J E., Talbot,~R W., Scheuer,~E M., Seid,~G., Avery,~M A., and Singh,~H B.: Aerosol chemical composition in Asian continental outflow during the TRACE-P campaign: Comparison with PEM-West B, J. Geophys. Res.-Atmos., 108, 8815, doi:10.1029/2002JD003111, 2003. Ekman,~A M L., Wang,~C., Strom,~J., and Krejci,~R.: Explicit simulation of aerosol physics in a~cloud-resolving model: Aerosol transport and processing in the free troposphere, J. Atmos. Sci., 63, 682–696, 2006. Ervens,~B., Feingold,~G., Frost,~G J., and Kreidenweis,~S M.: A~modeling study of aqueous production of dicarboxylic acids: 1. Chemical pathways and speciated organic mass production, J. Geophys. Res.-Atmos., 109, D15205, doi:10.1029/2003JD004387, 2004. Falkovich,~A H., Graber,~E R., Schkolnik,~G., Rudich,~Y., Maenhaut,~W., and Artaxo,~P.: Low molecular weight organic acids in aerosol particles from Rondônia, Brazil, during the biomass-burning, transition and wet periods, Atmos. Chem. Phys., 5, 781–797, 2005. Folkins,~I., Loewenstein,~M., Podolske,~J., Oltmans,~S J., and Proffitt,~M.: A~barrier to vertical mixing at 14 km in the tropics: Evidence from ozonesondes and aircraft measurements, J. Geophys. Res.-Atmos., 104, 22095–22102, 1999. Folkins,~I., Oltmans,~S J., and Thompson,~A M.: Tropical convective outflow and near surface equivalent potential temperatures, Geophys. Res. Lett., 27, 2549–2552, 2000. Folkins,~I.: Origin of lapse rate changes in the upper tropical troposphere, J. Atmos. Sci., 59, 992–1005, 2002. Fueglistaler,~S., Bonazzola,~M., Haynes,~P H., and Peter,~T.: Stratospheric water vapor predicted from the Lagrangian temperature history of air entering the stratosphere in the tropics, J. Geophys. Res.-Atmos., 110, D08107, doi:10.1029/2004JD005516, 2005. Fuzzi,~S., Decesari,~S., Facchini,~M C., Cavalli,~F., Emblico,~L., Mircea,~M., Andreae,~M O., Trebs,~I., Hoffer,~A., Guyon,~P., Artaxo,~P., Rizzo,~L V., Lara,~L L., Pauliquevis,~T., Maenhaut,~W., Raes,~N., Chi,~X G., Mayol-Bracero,~O L., Soto-Garcia,~L L., Claeys,~M., Kourtchev,~I., Rissler,~J., Swietlicki,~E., Tagliavini,~E., Schkolnik,~G., Falkovich,~A H., Rudich,~Y., Fisch,~G., and Gatti,~L V.: Overview of the inorganic and organic composition of size-segregated aerosol in Rondonia, Brazil, from the biomass-burning period to the onset of the wet season, J. Geophys. Res.-Atmos., 112, D01201, doi:10.1029/2005JD006741, 2007a. Fuzzi,~S., Decesari,~S., Facchini,~M C., Cavalli,~F., Emblico,~L., Mircea,~M., Andreae,~M O., Trebs,~I., Hoffer,~A., Guyon,~P., Artaxo,~P., Rizzo,~L V., Lara,~L L., Pauliquevis,~T., Maenhaut,~W., Raes,~N., Chi,~X G., Mayol-Bracero,~O L., Soto-Garcia,~L L., Claeys,~M., Kourtchev,~I., Rissler,~J., Swietlicki,~E., Tagliavini,~E., Schkolnik,~G., Falkovich,~A H., Rudich,~Y., Fisch,~G., and Gatti,~L V.: Overview of the inorganic and organic composition of size-segregated aerosol in Rondonia, Brazil, from the biomass-burning period to the onset of the wet season, J. Geophys. Res.-Atmos., 112, D01201, doi:10.1029/2005JD006741, 2007b. Gettelman,~A., Salby,~M L., and Sassi,~F.: Distribution and influence of convection in the tropical tropopause region, J. Geophys. Res.-Atmos., 107, 4080, doi:10.1029/2001JD001048, 2002. Gettelman,~A., Forster,~P M D., Fujiwara,~M., Fu,~Q., Vomel,~H., Gohar,~L K., Johanson,~C., and Ammerman,~M.: Radiation balance of the tropical tropopause layer, J. Geophys. Res.-Atmos., 109, D07103, doi:10.1029/2003JD004190, 2004. Gondwe,~M., Krol,~M., Gieskes,~W., Klaassen,~W., and de Baar,~H.: The contribution of ocean-leaving DMS to the global atmospheric burdens of DMS, MSA, \chemSO_2, and NSS \chemSO_4$^=$, Global. Biogeochem. Cy., 17, 1056, doi:10.1029/2002GB001937, 2003. Graham,~B., Mayol-Bracero,~O L., Guyon,~P., Roberts,~G C., Decesari,~S., Facchini,~M C., Artaxo,~P., Maenhaut,~W., Koll,~P., and Andreae,~M O.: Water-soluble organic compounds in biomass burning aerosols over Amazonia – 1. Characterization by NMR and GC-MS, J. Geophys. Res.-Atmos., 107, 8047, doi:10.1029/2001JD000336, 2002. Graham,~B., Guyon,~P., Maenhaut,~W., Taylor,~P E., Ebert,~M., Matthias-Maser,~S., Mayol-Bracero,~O L., Godoi,~R H M., Artaxo,~P., Meixner,~F X., Moura,~M A L., Rocha,~C H E D., Van Grieken,~R., Glovsky,~M M., Flagan,~R C., and Andreae,~M O.: Composition and diurnal variability of the natural Amazonian aerosol, J. Geophys. Res.-Atmos., 108, 4765, doi:10.1029/2003JD004049, 2003a. Graham,~B., Guyon,~P., Taylor,~P E., Artaxo,~P., Maenhaut,~W., Glovsky,~M M., Flagan,~R C., and Andreae,~M O.: Organic compounds present in the natural Amazonian aerosol: Characterization by gas chromatography-mass spectrometry, J. Geophys. Res.-Atmos., 108, 4766, doi:10.1029/2003JD003990, 2003b. Gras,~J L.: Change in nature of stratospheric aerosol collected at 34-degrees-S, Nature, 271, 231–232, 1978. Highwood,~E J. and Hoskins,~B J.: The tropical tropopause, Q. J. Roy. Meteor. Soc., 124, 1579–1604, 1998. Holton,~J R. and Gettelman,~A.: Horizontal transport and the dehydration of the stratosphere, Geophys. Res. Lett., 28, 2799–2802, 2001. Hong,~G., Yang,~P., Gao,~B C., Baum,~B A., Hu,~Y X., King,~M D., and Platnick,~S.: High cloud properties from three years of MODIS terra and aqua collection-4 data over the tropics, J. Appl. Meteorol. Clim., 46, 1840–1856, 2007. Hudson,~P K., Murphy,~D M., Cziczo,~D J., Thomson,~D S., de Gouw,~J A., Warneke,~C., Holloway,~J., Jost,~J R., and Hubler,~G.: Biomass-burning particle measurements: Characteristic composition and chemical processing, J. Geophys. Res.-Atmos., 109, D23S27, doi:10.1029/2003JD004398, 2004. Huebert,~B J., Zhuang,~L Z., Howell,~S., Noone,~K., and Noone,~B.: Sulfate, nitrate, methanesulfonate, chloride, ammonium, and sodium measurements from ship, island, and aircraft during the atlantic stratocumulus transition experiment marine aerosol gas exchange, J. Geophys. Res.-Atmos., 101, 4413–4423, 1996. Iraci,~L T., Essin,~A M., and Golden,~D M.: Solubility of methanol in low-temperature aqueous sulfuric acid and implications for atmospheric particle composition, J. Phys. Chem. A, 106, 4054–4060, 2002. Iraci,~L T., Riffel,~B G., Robinson,~C B., Michelsen,~R R., and Stephenson,~R M.: The acid catalyzed nitration of methanol: formation of methyl nitrate via aerosol chemistry, J. Atmos. Chem., 58, 253–266, 2007. Jensen,~E., and Pfister,~L.: Transport and freeze-drying in the tropical tropopause layer, J. Geophys. Res.-Atmos., 109, D02207, doi:10.1029/2003JD004022, 2004. Jensen,~E J., Toon,~O B., Pfister,~L., and Selkirk,~H B.: Dehydration of the upper troposphere and lower stratosphere by subvisible cirrus clouds near the tropical tropopause, Geophys. Res. Lett., 23, 825–828, 1996. Jensen,~E J., Smith,~J B., Pfister,~L., Pittman,~J V., Weinstock,~E M., Sayres,~D S., Herman,~R L., Troy,~R F., Rosenlof,~K., Thompson,~T L., Fridlind,~A M., Hudson,~P K., Cziczo,~D J., Heymsfield,~A J., Schmitt,~C., and Wilson,~J C.: Ice supersaturations exceeding 100% at the cold tropical tropopause: implications for cirrus formation and dehydration, Atmos. Chem. Phys., 5, 851–862, 2005. Jonsson,~H H., Wilson,~J C., Brock,~C A., Knollenberg,~R G., Newton,~R., Dye,~J E., Baumgardner,~D., Borrmann,~S., Ferry,~G V., Pueschel,~R., Woods,~D C., and Pitts,~M C.: Performance of a~Focused Cavity Aerosol Spectrometer for Measurements in the Stratosphere of Particle-Size in the 0.06–2.0-Mu-M-Diameter Range, J. Atmos. Ocean. Tech., 12, 115–129, 1995. Kavouras,~I G. and Stephanou,~E G.: Direct evidence of atmospheric secondary organic aerosol formation in forest atmosphere through heteromolecular nucleation, Environ. Sci. Technol., 36, 5083–5091, 2002. Kazil,~J., Lovejoy,~E R., Barth,~M C., and O'Brien,~K.: Aerosol nucleation over oceans and the role of galactic cosmic rays, Atmos. Chem. Phys., 6, 4905–4924, 2006. Kelly,~K K., Proffitt,~M H., Chan,~K R., Loewenstein,~M., Podolske,~J R., Strahan,~S E., Wilson,~J C., and Kley,~D.: Water-vapor and cloud water measurements over Darwin during the step 1987 tropical mission, J. Geophys. Res.-Atmos., 98, 8713–8723, 1993. Kesselmeier,~J., Kuhn,~U., Rottenberger,~S., Biesenthal,~T., Wolf,~A., Schebeske,~G., Andreae,~M O., Ciccioli,~P., Brancaleoni,~E., Frattoni,~M., Oliva,~S T., Botelho,~M L., Silva,~C M A., and Tavares,~T M.: Concentrations and species composition of atmospheric volatile organic compounds (VOCs) as observed during the wet and dry season in Rondonia (Amazonia), J. Geophys. Res.-Atmos., 107, 8053, doi:10.1029/2000JD000267, 2002. Knollenberg,~R G., Kelly,~K., and Wilson,~J C.: Measurements of high number densities of ice crystals in the tops of tropical cumulonimbus, J. Geophys. Res.-Atmos., 98, 8639–8664, 1993. Kritz,~M A., Rosner,~S W., Kelly,~K K., Loewenstein,~M., and Chan,~K R.: Radon measurements in the lower tropical stratosphere – evidence for rapid vertical transport and dehydration of tropospheric air, J. Geophys. Res.-Atmos., 98, 8725–8736, 1993. Kroll,~J H., Ng,~N L., Murphy,~S M., Flagan,~R C., and Seinfeld,~J H.: Secondary organic aerosol formation from isoprene photooxidation, Environ. Sci. Technol., 40, 1869–1877, 2006. Kuhn,~U., Rottenberger,~S., Biesenthal,~T., Ammann,~C., Wolf,~A., Schebeske,~G., Oliva,~S T., Tavares,~T M., and Kesselmeier,~J.: Exchange of short-chain monocarboxylic acids by vegetation at a~remote tropical forest site in Amazonia, J. Geophys. Res.-Atmos., 107, 8069, doi:10.1029/2000JD000303, 2002. Kupper,~C., Thuburn,~J., Craig,~G C., and Birner,~T.: Mass and water transport into the tropical stratosphere: A~cloud-resolving simulation, J. Geophys. Res.-Atmos., 109, D10111, doi:10.1029/2004JD004541, 2004. Lawson,~R P., Pilson,~B., Baker,~B., Mo,~Q., Jensen,~E., Pfister,~L., and Bui,~P.: Aircraft measurements of microphysical properties of subvisible cirrus in the tropical tropopause layer, Atmos. Chem. Phys., 8, 1609–1620, 2008. Lee,~S H., Murphy,~D M., Thomson,~D S., and Middlebrook,~A M.: Nitrate and oxidized organic ions in single particle mass spectra during the 1999 Atlanta Supersite Project, J. Geophys. Res.-Atmos., 108(D7), 8417, doi:10.1029/2001JD001455, 2003a. Lee,~S H., Reeves,~J M., Wilson,~J C., Hunton,~D E., Viggiano,~A A., Miller,~T M., Ballenthin,~J O., and Lait,~L R.: Particle formation by ion nucleation in the upper troposphere and lower stratosphere, Science, 301, 1886–1889, 2003b. Lee,~Y N., Weber,~R., Ma,~Y., Orsini,~D., Maxwell-Meier,~K., Blake,~D., Meinardi,~S., Sachse,~G., Harward,~C., Chen,~T Y., Thornton,~D., Tu,~F H., and Bandy,~A.: Airborne measurement of inorganic ionic components of fine aerosol particles using the particle-into-liquid sampler coupled to ion chromatography technique during ACE-Asia and TRACE-P, J. Geophys. Res.-Atmos., 108, 8646, doi:10.1029/2002JD003265, 2003. Lim,~H J., Carlton,~A G., and Turpin,~B J.: Isoprene forms secondary organic aerosol through cloud processing: Model simulations, Environ. Sci. Technol., 39, 4441–4446, 2005. Liu,~C T. and Zipser,~E J.: Global distribution of convection penetrating the tropical tropopause, J. Geophys. Res.-Atmos., 110, D23104, doi:10.1029/2005JD006063, 2005. Liu,~C T.: Geographical and seasonal distribution of tropical tropopause thin clouds and their relation to deep convection and water vapor viewed from satellite measurements, J. Geophys. Res.-Atmos., 112, D09205, doi:10.1029/2006JD007479, 2007. Lovejoy,~E R., Curtius,~J., and Froyd,~K D.: Atmospheric ion-induced nucleation of sulfuric acid and water, J. Geophys. Res.-Atmos., 109, D08204, doi:10.1029/2003jd004460, 2004. Luo,~B P., Peter,~T., Fueglistaler,~S., Wernli,~H., Wirth,~M., Kiemle,~C., Flentje,~H., Yushkov,~V A., Khattatov,~V., Rudakov,~V., Thomas,~A., Borrmann,~S., Toci,~G., Mazzinghi,~P., Beuermann,~J., Schiller,~C., Cairo,~F., Di Donfrancesco,~G., Adriani,~A., Volk,~C M., Strom,~J., Noone,~K., Mitev,~V., MacKenzie,~R A., Carslaw,~K S., Trautmann,~T., Santacesaria,~V., and Stefanutti,~L.: Dehydration potential of ultrathin clouds at the tropical tropopause, Geophys. Res. Lett., 30, 1557, doi:10.1029/2002GL016737, 2003. Ma,~Y., Weber,~R J., Maxwell-Meier,~K., Orsini,~D A., Lee,~Y N., Huebert,~B J., Howell,~S G., Bertram,~T., Talbot,~R W., Dibb,~J E., and Scheuer,~E.: Intercomparisons of airborne measurements of aerosol ionic chemical composition during TRACE-P and ACE-Asia, J. Geophys. Res.-Atmos., 109, D15S06, doi:10.1029/2003JD003673, 2004. Mayol-Bracero,~O L., Guyon,~P., Graham,~B., Roberts,~G., Andreae,~M O., Decesari,~S., Facchini,~M C., Fuzzi,~S., and Artaxo,~P.: Water-soluble organic compounds in biomass burning aerosols over Amazonia – 2. Apportionment of the chemical composition and importance of the polyacidic fraction, J. Geophys. Res.-Atmos., 107, 8091, doi:10.1029/2001JD000522, 2002. McFarquhar,~G M., Heymsfield,~A J., Spinhirne,~J., and Hart,~B.: Thin and subvisual tropopause tropical cirrus: Observations and radiative impacts, J. Atmos. Sci., 57, 1841–1853, 2000. Michelsen,~R R., Staton,~S J R., and Iraci,~L T.: Uptake and dissolution of gaseous ethanol in sulfuric acid, J. Phys. Chem. A, 110, 6711–6717, 2006. Möhler,~O., Field,~P R., Connolly,~P., Benz,~S., Saathoff,~H., Schnaiter,~M., Wagner,~R., Cotton,~R., Kramer,~M., Mangold,~A., and Heymsfield,~A J.: Efficiency of the deposition mode ice nucleation on mineral dust particles, Atmos. Chem. Phys., 6, 3007–3021, 2006. Möhler,~O., Benz,~S., Saathoff,~H., Schnaiter,~M., Wagner,~R., Schneider,~J., Walter,~S., Ebert,~V., and Wagner,~S.: The effect of organic coating on the heterogeneous ice nucleation efficiency of mineral dust aerosols, Environ. Res. Lett., 3, 025007, doi:10.1088/1748–9326/3/2/025007, 2008. Munger,~J W., Tiller,~C., and Hoffmann,~M R.: Identification of Hydroxymethanesulfonate in Fog Water, Science, 231, 247–249, 1986. Murphy,~D M., Middlebrook,~A M., and Warshawsky,~M.: Cluster analysis of data from the Particle Analysis by Laser Mass Spectrometry (PALMS) instrument, Aerosol. Sci. Tech., 37, 382–391, 2003. Murphy,~D M., Cziczo,~D J., Froyd,~K D., Hudson,~P K., Matthew,~B M., Middlebrook,~A M., Peltier,~R E., Sullivan,~A., Thomson,~D S., and Weber,~R J.: Single-particle mass spectrometry of tropospheric aerosol particles, J. Geophys. Res.-Atmos., 111, D23S32, doi:10.1029/2006JD007340, 2006. Murphy,~D M., Cziczo,~D J., Hudson,~P K., and Thomson,~D S.: Carbonaceous material in aerosol particles in the lower stratosphere and tropopause region, J. Geophys. Res.-Atmos., 112, D04203, doi:10.1029/2006JD007297, 2007. Murray,~B J.: Inhibition of ice crystallisation in highly viscous aqueous organic acid droplets, Atmos. Chem. Phys., 8, 5423–5433, 2008. Ng,~N L., Chhabra,~P S., Chan,~A W H., Surratt,~J D., Kroll,~J H., Kwan,~A J., McCabe,~D C., Wennberg,~P O., Sorooshian,~A., Murphy,~S M., Dalleska,~N F., Flagan,~R C., and Seinfeld,~J H.: Effect of NO_x level on secondary organic aerosol (SOA) formation from the photooxidation of terpenes, Atmos. Chem. Phys., 7, 5159–5174, 2007. Ng,~N L., Kwan,~A J., Surratt,~J D., Chan,~A W H., Chhabra,~P S., Sorooshian,~A., Pye,~H O T., Crounse,~J D., Wennberg,~P O., Flagan,~R C., and Seinfeld,~J H.: Secondary organic aerosol (SOA) formation from reaction of isoprene with nitrate radicals (\chemNO_3), Atmos. Chem. Phys., 8, 4117–4140, 2008. Nguyen,~H N., Martinsson,~B G., Wagner,~J B., Carlemalm,~E., Ebert,~M., Weinbruch,~S., Brenninkmeijer,~C A M., Heintzenberg,~J., Hermann,~M., Schuck,~T., van Velthoven,~P F J., and Zahn,~A.: Chemical composition and morphology of individual aerosol particles from a~CARIBIC flight at 10 \unitkm altitude between 50 degrees N and 30 degrees S, J. Geophys. Res.-Atmos., 113, D23209, doi:10.1029/2008JD009956, 2008. Nozière,~B., Dziedzic,~P., and Córdova,~A.: Common inorganic ions are efficient catalysts for organic reactions in atmospheric aerosols and other natural environments, Atmos. Chem. Phys. Discuss., 9, 1–21, 2009. Park,~S., Jiménez,~R., Daube,~B C., Pfister,~L., Conway,~T J., Gottlieb,~E W., Chow,~V Y., Curran,~D J., Matross,~D M., Bright,~A., Atlas,~E L., Bui,~T P., Gao,~R S., Twohy,~C H., and Wofsy,~S C.: The \chemCO_2 tracer clock for the Tropical Tropopause Layer, Atmos. Chem. Phys., 7, 3989–4000, 2007. Peltier,~R E., Sullivan,~A P., Weber,~R J., Brock,~C A., Wollny,~A G., Holloway,~J S., de Gouw,~J A., and Warneke,~C.: Fine aerosol bulk composition measured on WP-3-D research aircraft in vicinity of the Northeastern United States – results from NEAQS, Atmos. Chem. Phys., 7, 3231–3247, 2007. Pfister,~L., Chan,~K R., Bui,~T P., Bowen,~S., Legg,~M., Gary,~B., Kelly,~K., Proffitt,~M., and Starr,~W.: Gravity-waves generated by a~tropical cyclone during the step tropical field program – a~case-study, J Geophys. Res.-Atmos., 98, 8611–8638, 1993. Pfister,~L., Selkirk,~H B., Jensen,~E J., Schoeberl,~M R., Toon,~O B., Browell,~E V., Grant,~W B., Gary,~B., Mahoney,~M J., Bui,~T V., and Hintsa,~E.: Aircraft observations of thin cirrus clouds near the tropical tropopause, J. Geophys. Res.-Atmos., 106, 9765–9786, 2001. Prenni,~A J., DeMott,~P J., Twohy,~C., Poellot,~M R., Kreidenweis,~S M., Rogers,~D C., Brooks,~S D., Richardson,~M S., and Heymsfield,~A J.: Examinations of ice formation processes in Florida cumuli using ice nuclei measurements of anvil ice crystal particle residues, J. Geophys. Res.-Atmos., 112, D10221, doi:10.1029/2006JD007549, 2007. Putaud,~J P., Van Dingenen,~R., Mangoni,~M., Virkkula,~A., Raes,~F., Maring,~H., Prospero,~J M., Swietlicki,~E., Berg,~O H., Hillamo,~R., and Makela,~T.: Chemical mass closure and assessment of the origin of the submicron aerosol in the marine boundary layer and the free troposphere at Tenerife during ACE-2, Tellus B, 52, 141–168, 2000. Rosenfield,~J E., Considine,~D B., Schoeberl,~M R., and Browell,~E V.: The impact of subvisible cirrus clouds near the tropical tropopause on stratospheric water vapor, Geophys. Res. Lett., 25, 1883–1886, 1998. Rottenberger,~S., Kuhn,~U., Wolf,~A., Schebeske,~G., Oliva,~S T., Tavares,~T M., and Kesselmeier,~J.: Exchange of short-chain aldehydes between Amazonian vegetation and the atmosphere, Ecol. Appl., 14, S247–S262, 2004. Rudich,~Y.: Laboratory perspectives on the chemical transformations of organic matter in atmospheric particles, Chem. Rev., 103, 5097–5124, 2003. Singh,~H B., Salas,~L J., Chatfield,~R B., Czech,~E., Fried,~A., Walega,~J., Evans,~M J., Field,~B D., Jacob,~D J., Blake,~D., Heikes,~B., Talbot,~R., Sachse,~G., Crawford,~J H., Avery,~M A., Sandholm,~S., and Fuelberg,~H.: Analysis of the atmospheric distribution, sources, and sinks of oxygenated volatile organic chemicals based on measurements over the Pacific during TRACE-P, J. Geophys. Res.-Atmos., 109, D15S07, doi:10.1029/2003JD003883, 2004. Sorooshian,~A., Lu,~M L., Brechtel,~F J., Jonsson,~H., Feingold,~G., Flagan,~R C., and Seinfeld,~J H.: On the source of organic acid aerosol layers above clouds, Environ. Sci. Technol., 41, 4647–4654, 2007a. Sorooshian,~A., Ng,~N L., Chan,~A W H., Feingold,~G., Flagan,~R C., and Seinfeld,~J H.: Particulate organic acids and overall water-soluble aerosol composition measurements from the 2006 Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS), J. Geophys. Res.-Atmos., 112, D13201, doi:10.1029/2007JD008537, 2007b. Thomson,~D S., Schein,~M E., and Murphy,~D M.: Particle analysis by laser mass spectrometry WB-57F instrument overview, Aerosol. Sci. Tech., 33, 153–169, 2000. Toracinta,~E R., Cecil,~D J., Zipser,~E J., and Nesbitt,~S W.: Radar, passive microwave, and lightning characteristics of precipitating systems in the tropics, Mon. Weather. Rev., 130, 802–824, 2002. von Glasow,~R. and Crutzen,~P J.: Model study of multiphase DMS oxidation with a~focus on halogens, Atmos. Chem. Phys., 4, 589–608, 2004. Wang,~P H., Minnis,~P., McCormick,~M P., Kent,~G S., and Skeens,~K M.: A~6-year climatology of cloud occurrence frequency from stratospheric aerosol and gas experiment II observations (1985–1990), J. Geophys. Res.-Atmos., 101, 29407–29429, 1996. Wennberg,~P O., Hanisco,~T F., Jaegle,~L., Jacob,~D J., Hintsa,~E J., Lanzendorf,~E J., Anderson,~J G., Gao,~R S., Keim,~E R., Donnelly,~S G., Del Negro,~L A., Fahey,~D W., McKeen,~S A., Salawitch,~R J., Webster,~C R., May,~R D., Herman,~R L., Proffitt,~M H., Margitan,~J J., Atlas,~E L., Schauffler,~S M., Flocke,~F., McElroy,~C T., and Bui,~T P.: Hydrogen radicals, nitrogen radicals, and the production of O-3 in the upper troposphere, Science, 279, 49–53, 1998. Whiteaker,~J R. and Prather,~K A.: Hydroxymethanesulfonate as a~tracer for fog processing of individual aerosol particles, Atmos. Environ., 37, 1033–1043, 2003. Wilson,~J C., Lee,~S H., Reeves,~J M., Brock,~C A., Jonsson,~H H., Lafleur,~B G., Loewenstein,~M., Podolske,~J., Atlas,~E., Boering,~K., Toon,~G., Fahey,~D., Bui,~T P., Diskin,~G., and Moore,~F.: Steady-state aerosol distributions in the extra-tropical, lower stratosphere and the processes that maintain them, Atmos. Chem. Phys., 8, 6617–6626, 2008. Winker,~D M. and Trepte,~C R.: Laminar cirrus observed near the tropical tropopause by LITE, Geophys. Res. Lett., 25, 3351–3354, 1998. Zhu,~L., Nenes,~A., Wine,~P H., and Nicovich,~J M.: Effects of aqueous organosulfur chemistry on particulate methanesulfonate to non-sea salt sulfate ratios in the marine atmosphere, J. Geophys. Res.-Atmos., 111, D05316, doi:10.1029/2005JD006326, 2006. Zobrist,~B., Marcolli,~C., Pedernera,~D A., and Koop,~T.: Do atmospheric aerosols form glasses?, Atmos. Chem. Phys., 8, 5221–5244, 2008.