Dimethylamine as a major alkyl amine species in particles and cloud water: Observations in semi-arid and coastal regions

Abstract

Aerosol and cloud water measurements of dimethylamine (DMA), the most abundant amine in this study, were conducted in semi-arid (Tucson, Arizona) and marine (Nucleation in California Experiment, NiCE; central coast of California) areas. In both regions, DMA exhibits a unimodal aerosol mass size distribution with a dominant peak between 0.18 and 0.56 μm. Particulate DMA concentrations increase as a function of marine biogenic emissions, sulfate, BVOC emissions, and aerosol-phase water. Such data supports biogenic sources of DMA, aminium salt formation, and partitioning of DMA to condensed phases. DMA concentrations exhibit positive correlations with various trace elements and most especially vanadium, which warrants additional investigation. Cloud water DMA levels are enhanced significantly during wildfire periods unlike particulate DMA levels, including in droplet residual particles, due to effective dissolution of DMA into cloud water and probably DMA volatilization after drop evaporation. DMA:NH+4 molar ratios peak between 0.18 and 1.0 μm depending on the site and time of year, suggesting that DMA competes better with NH3 in those sizes in terms of reactive uptake by particles.

Atmospheric Research Over the Western North Atlantic Ocean Region and North American East Coast: A Review of Past Work and Challenges Ahead

“…It is well known that ocean ecosystems emit DMS gas that subsequently oxidizes to form either methanesulfonic acid (MSA) or SO 2 , the latter of which can eventually form particulate SO 4 2‐ . SOA can also be formed in the MBL due to emissions of marine biogenic VOCs, including end products such as alkyl amines (Facchini, Decesari, et al, ; Youn et al, ) among others. It has also been hypothesized that increased organic compounds in the seawater translate into elevated organic aerosol emissions via bubble‐bursting processes.…”

Particulate trimethylamine in the summertime Canadian high Arctic lower troposphere

“…So far, this research has shown that amines may take part in aerosol chemistry in several ways. These include acid-base reactions to form aminium salts and dissolution in cloud droplets (owing to their high water solubility) where subsequent acid-base reactions can occur in the aqueous phase (e.g., Glasoe et al, 2015;Dawson et al, 2012;Erupe et al, 2011;Ge et al, 2011b;Jen et al, 2016Jen et al, , 2014Youn et al, 2015;Yu et al, 2012;Rehbein et al, 2011;Pankow, 2015). Amines compete with ammonia (NH 3 ) in neutralizing acidic aerosol.…”

Analysis of remotely sensed and surface data of aerosols and meteorology for the Mexico Megalopolis Area between 2003 and 2015

“…[]. Ammonium and SO 4 2− often exhibit the same mass size distribution with peaks in the accumulation mode, indicative of secondary formation via acid‐base chemistry [e.g., Maudlin et al ., ; Youn et al ., ]. Sources of NH 3 include livestock waste, fertilizer, biomass burning, and vehicular emissions [ Battye et al ., ].…”