Important source of marine secondary organic aerosol from biogenic amines.
Relevant concentrations of dimethyl- and diethylammonium salts (DMA+ and DEA+) were measured in submicrometer marine aerosol collected over the North Atlantic during periods of high biological activity (HBA) in clean air masses (median concentration (minimum-maximum)=26(6-56) ng m(-3)). Much lower concentrations were measured during periods of low biological activity (LBA): 1 (<0.4-20) ng m(-3) and when polluted air masses were advected to the sampling site: 2 (<0.2-24) ng m(-3). DMA+ and DEA+ are the most abundantorganic species, second only to MSA, detected in fine marine particles representing on average 11% of the secondary organic aerosol (SOA) fraction and a dominant part (35% on average) of the water-soluble organic nitrogen (WSON). Several observations support the hypothesis that DMA+ and DEA+ have a biogenic oceanic source and are produced through the reaction of gaseous amines with sulfuric acid or acidic sulfates. Moreover, the water-soluble fraction of nascent marine aerosol particles produced by bubble-bursting experiments carried out in parallel to ambient aerosol sampling over the open ocean showed WSON, DMA+, and DEA+ concentrations always below the detection limit, thus excluding an important primary sea spray source.
Facchini
Maria Cristina
MC
Institute of Atmospheric Sciences and Climate, National Research Council, Bologna, I-40129, Italy. mc.facchini@isac.cnr.it
Decesari
Stefano
S
Rinaldi
Matteo
M
Carbone
Claudio
C
Finessi
Emanuela
E
Mircea
Mihaela
M
Fuzzi
Sandro
S
Moretti
Fabio
F
Tagliavini
Emilio
E
Ceburnis
Darius
D
O'Dowd
Colin D
CD
D000336:Aerosols / Q000032:analysis*; D001679:Biogenic Amines / Q000737:chemistry*; D056890:Eukaryota / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009930:Organic Chemicals / Q000032:analysis*; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012621:Seasons; D012623:Seawater / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D000336:Aerosols; D001679:Biogenic Amines; D009930:Organic Chemicals; D052638:Particulate Matter; D000644:Quaternary Ammonium Compounds; D014867:Water