Formation of Asian dust-storm particles mixed internally with sea salt in the atmosphere

In the spring of 1991, individual aerosol particles were collected on electron microscopic grids in Beijing (China) and Nagasaki (Japan). In order to study the change in the chemical composition of Asian dust-storm particles during transport, the dust particles were examined using an electron microscope equipped with an energy-dispersive X-ray (EDX) analyzer. An isentropic backward-trajectory analysis was carried out in order to obtain the transport path of the dust-storm particles. Spatial distributions of clouds by the Geostationary Meteorological Satellite (GMS) were also used in order to examine the presence of clouds along the transport path. Asian dust-storm particles mixed internally with sea salt (mixed particles) ranged from 16 to 100 % among the dust particles in the air over Nagasaki. For the two cases that the same dust-storm events were observed in Beijing and Nagasaki, dust-storm particles containing sea salt were present abundantly in Nagasaki in a case that the air would have been influenced largely by clouds in the maritime atmosphere during the transport. It is suggested that these mixed dust-storm particles were formed by cloud processes.