Environmental Analysis on the yellow Sand Events and Atmospheric Optics in Nagasaki Districts, Japan

(1)编制了长崎海洋观测站1914 ~ 2001年88年沙尘暴日数的长期变化趋势。这一统计分析表明，最近几年沙尘暴频繁发生。(2)光学粒子计数器对两年的大气气溶胶测量结果表明，沙尘事件中大粒子大量出现，但有时小粒子密度也较高，可能是来自亚洲大陆的大气污染物。(3)利用本课题新研制的天空辐射计和国家环境研究所的双波长激光雷达系统探测矿物粉尘颗粒的垂直剖面。他们的综合观测数据显示出非常有趣的特征，然后我们将分析沙尘颗粒的结构和运动，以构建沙尘暴事件的实质性图像。

(1) The long range trend of the number of days of yellow sand dust events observed at Nagasaki Marine Observatory were compiled for the 88 years from 1914 to 2001. This statistical analysis suggests the frequent occurrence of duststorm in latest Several years.(2) The measurements of atmospheric aerosols by an optical particle counter for two years showed that a great deal of large particles was significant at the dust events, but sometimes the density of smaller particles was also on higher level, which would suggest the atmospheric pollutants from the Asian continent.(3) A sky radiometer newly innovated in this research project and a dual wavelength laser radar system, which came from National Institute of Environmental Studies, was also utilized for sounding the vertical profiles of the mineral dust particles. Their synthetic observational data showed very interesting feature, and then we are now going to analyze the structure and movement of dust particles for constructing the substantial image of the yellow sand dust event.