半干旱区春季沙尘气溶胶谱分布的观测研究

为研究半干旱区沙尘细粒子的粒谱特征,利用WPS粒谱仪对内蒙古朱日和地区春季粒径为0.01~10.0mm的沙尘气溶胶进行了40多天的连续观测,得到不同天气条件下的气溶胶谱分布.研究表明,沙尘气溶胶有明显的日分布规律,不同天气背景下的沙尘气溶胶浓度变化特征不同,受气象要素影响较大.非沙尘日和沙尘日均有浓度变化较稳定的粒径段,沙尘日出现稳定粒径段的粒径小于非沙尘日,2种天气背景下的平均谱在0.07~0.20mm;非沙尘日、沙尘日和沙尘时段的气溶胶谱型在0.01~0.1mm、0.1~1.0mm和1.0~10mm 3个粒径段分布明显不同,分别符合对数正态分布、Lorentz分布和负指数分布.

Size distribution of dust aerosol particles in semi-arid region in spring.

To understand the size distribution characteristics of dust aerosol in semi-arid region, observation of dust aerosol was measured by WPS in Jurh of Inner Monoglia Autonomous Region of China between 11th March and 20th April 2006. A lot of data were collected under different weather conditions such as fine, sand-blowing, sandstorm and so on. There was clearly daily characteristic of dust aerosol under different weather conditions. The wind velocity and the humidity affected the size distribution of dust aerosol remarkably. Moreover, there was a steady size interval in which the number concentration had little change between different days for non-dust events and dust events. The dust size distributions were lognormal characteristic between 0.01 to 0.1μm, lorentz between 0.1 to 1.0μm and Junge between 1.0~10μm.