Abstract:The particle size distribution is not only affected by meteorological factors such as temperature, air humidity and wind, but also closely regulated by the boundary layer mixing such as turbulence. Based on the simultaneously observed meteorological factors and particle size distribution in the range of 14.6-660.0 nm in November 2018, the impact of different meteorological factors, especially turbulence, on the particle size distribution is investigated to further understand the roles of meteorological factors in haze development. The results show that the increased relative humidity can reduce the total particle number concentration (TPNC) in nuclear mode and Aitken mode, but raise the TPNC in accumulation mode. Warmed temperature can increase the TPNC in the nuclear mode. The increase of wind speed, turbulent kinetic energy, frictional velocity and turbulence intensity can dilute and remove the particles in the Aitken and accumulation modes, but enhance the TPNC in the nuclear mode. In contrast to the diurnal variation of turbulence, the TPNC in Aitken mode and accumulation mode is low in the daytime but higher in the nighttime. In clean days, the TPNC in the nuclear mode continues to rise in the afternoon and reaches a peak in the late afternoon. A time lag has been found in the nuclear mode TPNC increase in contrast to the turbulence development. After the turbulence develops for 3 to 5 hours, the TPNC in nuclear mode begins to increase significantly.