AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Chemical Characteristics of Submicrometer Particles at a Coastal Site in Korea
Jiyeon Park, KwangYul Lee, Min Soo Kang, HungSoo Joo, Hyunji, Kim Kim, Seunghee Han, Leah Williams, MINHAN PARK, Dohyung Kim, Kihong Park, Gwangju Institute of Science and Technology
Abstract Number: 620 Working Group: Aerosol Chemistry
Abstract Chemical components (organics, sulfate, nitrate, ammonium, chloride, methane sulfonic acid (MSA), and black carbon (BC)) of submicrometer particles in the coastal atmosphere were measured with an aerosol mass spectrometer (AMS) and an Aethalometer at the sampling site of Boseong, South Korea in the fall of 2012. Also, concentrations of chlorophyll-a, bacteria, and viruses in seawater were determined to find any relationship between the production of marine organic aerosols and biological materials in seawater. The organics was found to be the most dominant species (33.9%) with an average concentration of 1.44±0.50 µg/m3 in the ambient particulate matter less than 1 µm (PM1). Average mass concentrations of sulfate, ammonium, nitrate, chloride, MSA, and BC were 1.15±0.59, 0.65±0.52, 0.44±0.29, 0.06±0.02, 0.10±0.02, and 0.40±0.27 µg/m3, respectively. The PM1 concentration and the characteristics of organics were strongly dependent on the air mass type. The highest PM1 was observed with the northwest continental air mass (nitrate, ammonium, sulfate, and organics increased 3-7 times compared to average values during the whole sampling period, but the increase of BC was not so high as other chemical components). Also, the less volatile-oxidized organic aerosols (LV-OOA) became dominant with the northwest continental air mass, suggesting that the organics were highly aged during the long-range transport. The AMS mass spectra of laboratory-cultured marine bacteria (e.g., Vibrio litoralis, Flavobacterium sp., and Pseudomonas aeruginosa) and natural seawater were determined after being sprayed from bubble bursting chamber. The m/z 54 and 95 were selected as biological organic markers to determine the biological fraction in the organic aerosols. The biological fraction varied from 1.2% to 6.8% with an average of ~2.8% and had low correlations with concentrations of chlorophyll-a and bacteria, and a moderate correlation with viruses (r=0.6) in seawaters. This might occur due to the low biological activities in seawater during the current sampling period (the average mass concentration of chlorophyll-a in seawater was 1.1 µg/l, and number concentrations of bacteria and viruses in seawater were 4.6×105 bacteria/ml and 1.1×107 viruses/ml, respectively).