AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Mixing State of Size-selected Submicrometer Particles in the Arctic (Ny-Ålesund, Svalbard) in the Spring and Fall of 2012
Kihong Park, GIBAEK KIM, Jae-Seok Kim, Young Jun Yoon, Hee-joo Cho, Gwangju Institute of Science and Technology
Abstract Number: 249 Working Group: Aerosols, Clouds, and Climate
Abstract Measurements of hygroscopicity, volatility, and mixing state of size-selected Aitkin and accumulation mode particles were conducted by hygroscopicity and volatility tandem differential mobility analyzer (HVTDMA) in the Arctic (Ny-Alesund, Svalbard) in May and September of 2012. In May, the accumulation mode particles were dominant with occasional observation of the Aitken mode particles. Appearance of the Aitken mode particles happened almost simultaneously at two locations which are ~2 km away from each other with different heights 61 m and 474 m above sea level, respectively, suggesting that they were produced regionally by nucleation. In September, the accumulation mode particles were suppressed, while the Aitken mode particles still exist. The less number of submicrometer particles in September might occur because the strength of the long-range transported aerosols became weak with the change of air mass flow pattern and more mixing happened. During the period of enhanced concentration of the Aitken mode particles, the average hygroscopic growth factor (HGF) and shrinkage factor (SF) of the Aitken mode particles were 1.46 and 0.88, respectively, without significant external mixing of different hygroscopic or volatile species, suggesting that the Aitken mode particles mostly consist of sulfates with some volatile organic species secondarily formed from biogenic marine sources. The accumulation mode particles displayed a significant external mixing of long-range transport aerosols and marine aerosols significantly, which were affected by the air mass transport pattern. Mixing structure of the accumulation mode particles was further examined by gradually increasing heater temperature up to 200 oC. The “more-volatile” particles were completely evaporated at 200 oC, and they had some volatile species at 100 oC, suggesting that the “more-volatile” particles should be an internal mixture of sulfate and volatile organics. On the other hand, the “less-volatile” particles are not completely evaporated at 200 oC, suggesting that they had some non-volatile species.