春末中国西北沙漠地区沙尘气溶胶物理特性的飞机观测

Aircraft Measurements of Sand Aerosol over Northwest China Desert Area in Late Spring

将APS-3310型激光空气动力学气溶胶粒子谱仪安装在飞机上, 于1999年春末对中国西北沙漠地区上空气溶胶进行探测.结果表明: 沙漠地区上空沙尘气溶胶粒子数浓度一般为1～10个*cm-3, 平均直径为1.6～4.6 μm, 最大直径为13.0～28.0 μm;TSP质量浓度为0.01～0.08 mg*m-3, PM2.5和PM10分别占TSP的3.6%～13.8%和50.3%～88.1%.高空沙尘气溶胶数浓度与下垫面状况密切相关, 沙漠地表上空的粒子数浓度高于植被覆盖较好的地区;当在沙漠地区上空飞行轨迹为上升、平飞、下降时, 沙尘气溶胶粒子谱呈现出由单峰偏态, 双峰, 正态到单峰偏态等形式的演变.

The sand aerosol number concentration is 1.0-10 · cm^-3 generally, mean diameter is 1.6-4.6 μm , the maximum is 13.0-28.0 μm; TSP is 0.01-0.08 mg · m^-3 ; the ratios of PM2.5 and PM10 to TSP are 3.6%-13.8% and 50.3%-88.1% respectively in the upper air of desert. Sand aerosol number concentration is closely related to the surface conditions, it shows aerosol number concentration is higher over desert than that of land with growing vegetables. The size distribution of aerosol varies with height.