Presentation Information
[AAS08-P22]Aerosol cycles in the coastal Antarctic regions
*Keiichiro Hara1, Nanami Mikami1, Kazuo Osada2, Naohiko Hirasawa3, Takashi Yamanouchi3, Masataka Shiobara3 (1.Fukuoka University, 2.Nagoya University, 3.National Institute of Polar Research)
Keywords:
Aerosols,Condensation nuclei,Antarctica
Antarctica is the cleanest regions because of isolation from human activities in mid-latitudes. Aerosols in the Antarctic troposphere are supplied dominantly from natural sources via primary and secondary processes. Secondary aerosols are associated with oceanic bioactivities, atmospheric chemistry, new particle formation (NPF), and growth. Condensation nuclei (CN) has been measured to monitor secondary aerosols even in the Antarctic region. Actually, CN concentrations have been measured in Syowa Station, Antarctica since April 1997. Seasonal variations of CN concentrations had minimum in winter and three maxima in September – October, December – January, and end-February – March at Syowa Station. Comparison with airmass origins computed using trajectory analysis showed that seasonal variations of CN concentrations related to seasonal features of UV radiation, oceanic bioactivity, and sea ice extent. Additionally, NPF and growth might proceed in free troposphere over the Antarctic continent and coastal regions and marine boundary layer (i.e., Southern Ocean). Also, long-term trend of CN concentrations at Syowa Station will be presented.