2005 Volume 56 Issue 7-8 Pages 273-301
Under the Japan-China joint project, "Studies on origin and transport of aeolian dust and its impact on climate (ADEC)", we have observed the aeolian dust in Beijing, Qingdao, and Hefei in China and Fukuoka, Nagoya, Tsukuba and Naha in Japan since the spring of 2001. The mass concentrations of total suspended particles (TSP) observed by the high-volume air sampler and size distribution observed by the low-volume air sampler were reported in this paper. In addition, the OPC observation in March 2004 and variation of dry deposition in Tsukuba were also reported. From the observation (2001-2004) of mass concentration of TSP we explained the seasonal and local variations. The dust concentration was generally high in spring and intensive observation periods (IOPs) were settled in spring each year. Some large dust events occurred during IOP-1 in April 2002 while dust storms were observed in IOP-2 (March 2003) and IOP-3 (March 2004). The particle size was a bimodal distribution that suggests natural and anthropogenic origins. When the dust storm occurred, the coarser particles increased. The optical particle counter (OPC) was used to understand the variations of size and number of aerosol particles in March 2004. The properties of aerosols varied hourly and it is shown that the OPC has much better time-resolution so it is very useful to observe the short-time variation of aerosols. The variation pattern of the flux of dry deposition in Tsukuba resembled roughly that of the TSP.
