@InProceedings{ZaveriWFZSZMNPTCSFMAM:2019:RaGrUr,
               author = "Zaveri, Rahul A. and Wang, Jian and Fan, Jiwen and Zang, Yuwei and 
                         Shilling, John and Zelenyuk, Alla and Mei, Fan and Newsom, Rob K. 
                         and Pekour, Mikhail S. and Tomlinson, Jason M. and Comstock, 
                         Jennifer M. and Shrivastava, ManishKumar and Fortner, Edward and 
                         Machado, Luiz Augusto Toledo and Artaxo, Paulo and Martin, Scot 
                         T.",
          affiliation = "{Pacific Northwest National Laboratory} and {Brookhaven Natl Lab} 
                         and {Pacific Northwest National Laboratory} and {Pacific Northwest 
                         National Laboratory} and {Pacific Northwest National Laboratory} 
                         and {Pacific Northwest National Laboratory} and {Pacific Northwest 
                         National Laboratory} and {Pacific Northwest National Laboratory} 
                         and {Pacific Northwest National Laboratory} and {Pacific Northwest 
                         National Laboratory} and {Pacific Northwest National Laboratory} 
                         and {Pacific Northwest National Laboratory} and {Aerodyne Research 
                         Inc.} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and 
                         {Universidade de S{\~a}o Paulo (USP)} and {Harvard University}",
                title = "Rapid growth of urban ultrafine aerosols and their impact on 
                         shallow clouds and precipitation in the Amazon rainforest",
                 year = "2019",
         organization = "AGU Fall Meeting",
             abstract = "As part of the Green Ocean Amazon (GoAmazon) field campaign in 
                         Brazil, the US Department of Energy G-1 aircraft was deployed to 
                         make semi-Lagrangian measurements of aerosols and trace gases over 
                         and downwind of Manaus, with the objective of investigating the 
                         interactions between urban and biogenic emissions. Here we focus 
                         on the rapid growth of anthropogenic ultrafine aerosols observed 
                         in the Manaus plume on 13 March 2014. Observations indicate that 
                         the ultrafine particles rapidly grew from about 20 nm to 50 nm at 
                         a sustained average rate of 11 nm h-1 largely due to secondary 
                         organic aerosol (SOA) formation from oxidation of biogenic 
                         volatile organic compounds. Lagrangian box model analysis of the 
                         evolving number and volume size distributions indicate that SOA 
                         growth kinetics was dominated by condensation of semivolatile 
                         organic compounds (SVOCs). Although SVOCs are conventionally 
                         assumed to equilibrate with organic aerosol mass and thereby 
                         promote the growth of large particles, our analysis shows that 
                         dynamic partitioning of SVOCs, with hindered uptake by large 
                         semisolid particles, facilitates the growth of small particles. We 
                         further demonstrate, via cloud-resolving model simulations, that 
                         the grown ultrafine particles significantly increase shallow cloud 
                         coverage and alter their droplet size distribution, suppress rain 
                         formation and enhance the vertical development of shallow clouds 
                         early in the cloud lifecycle, then augment the transition of 
                         shallow to deep convective clouds. These findings have important 
                         implications for representing SOA formation and phase-dependent 
                         particle growth mechanisms in aerosol-climate models.",
  conference-location = "San Francisco, CA",
      conference-year = "09-13 dec.",
             language = "en",
        urlaccessdate = "01 maio 2024"
}