天气条件及气团来源对青岛春季大气颗粒物数浓度谱分布的影响

利用2010年春季在青岛观测的不同粒径大气颗粒物数浓度,结合同期的Micaps天气图资料及后向轨迹分析资料,探讨了不同天气条件及气团来源不同时青岛大气颗粒物数浓度谱的变化特征.结果表明,沙尘发生前12h,大气中0.3~1.0μm的细粒子数浓度逐渐小幅升高,沙尘发生时>1.0μm粗颗粒物数浓度较沙尘发生前升高了1~10倍,0.3~1.0μm细颗粒物数浓度则降低了20%~45%.降雨使>1.0μm粗粒子数浓度降低>50%,降雨后大气颗粒物尤其是细粒子数浓度很快回升.雾和霾天气发生时1.0μm粗粒子数浓度较高,而局地源气溶胶中粗粒子数浓度较低,<0.7μm细粒子相对贡献较大.

Size distribution of atmospheric particles in number concentration in relation to meteorological conditions and air mass origins in Qingdao in spring

Number concentrations of atmospheric particles were measured in the suburban area of Qingdao in the spring of 2010.Size distributions of number concentrations of atmospheric particles were investigated in terms of impacts of meteorological conditions(e.g.,Micaps weather charts and the calculated air mass back trajectories) and various air mass origins.The results showed that number concentrations of particles at 0.3~1.0μm size range slightly increased since 12 hours prior to the dust events,then reduced by 20%~45% during dust events.However,number concentrations of particles > 1.0μm increased by a factor of 1~10 times during the dust events.Rainfall was found to remove more than 50% of particles >1.0μm from the atmosphere.It is interesting that number concentrations,especially in the submicron size range,increased rapidly post the rain.During fog and haze events,there were a significant increase of <1.0μm particles in number concentration.The increase was more obvious for 0.7~1.0μm particles in fog days and 0.5~0.7μm particles during haze events.The particle number concentrations and size distributions were also likely related to air mass trajectories.Air mass originated from Mongolia contains more super micron particles while the particles from the local air mass were mainly distributed in the <0.7μm size range.