Short-Term Variations in Aerosol Components during the Same Asian Dust (Kosa) Event Observed in Nagasaki, Japan and Beijing, China

We carried out short-term continuous monitoring of Asian dust every 2 hours in Beijing, China and Nagasaki, Japan and performed chemical analyses during 2 events where there were large differences in the characteristics of the Asian dust blowing into Nagasaki. The first involved typical Asian dust that originated in the Mongolian Gobi Desert on March 30, 2007 (abbreviated to TAD 2007). The second involved a polluted air parcel that arrived in Japan along with Asian dust on May 8, 2007. By comparing temporal changes in PM10 and particulate sulfur (sulfate ions) concentrations with the timing of the Asian dust arrival, we found in the April event (TAD 2007) that the polluted air parcel covering Beijing did not mix with an air parcel containing TAD 2007 coming from the north. In the May event, we inferred that mixing of the polluted air parcel and an air parcel containing Asian dust had occurred. The composition of aerosol particles in the air parcel reaching Nagasaki in the April event reflected the chemical composition of TAD 2007 itself, whereas that of the May event had high concentrations of chemical components originating in anthropogenic pollution, such as sulfate ions, zinc, lead and other heavy metals.