Aircraft measurements of vertical ultrafine particles profiles over Northern China coastal areas during dust storms in 2006

The vertical distribution of ultrafine particles over Northern China coastal areas was measured by aircraft equipped with a high space-time resolution instrument during dust storms in Spring of 2006. Three different types of conditions were observed, i.e. dust storm, weak dust storm and non-dust storm. Results indicate that the number concentration of ultrafine particles can reach up to 1.2 x 10(5) cm(3) during weak dust storm. It is found that the peak of newly formed particle by nucleation appeared around 10 nm diameter. During the dust Storms, the concentration of ultrafine particles was lower than those when no dust storms occurred, and the number concentration showed multiple-peak distribution, which needs further research. Our observational results may provide valuable information for recognizing the process and mechanism of air Pollution in the Northern China area, and basic parameters for model calculation. (C) 2008 Elsevier Ltd. All rights reserved.