Observations of Nucleation Mode Particles Formation and Growth on Mount Huang, China

Abstract

The growth of nucleation mode particles is analyzed using the measured data of aerosol particle size distribution, trace gas and meteorological parameters collected on Mount Huang, China from September 22 to October 28, 2012. The new particle formation (NPF) events were observed on average 18.2% of all measurement days and all occurred before the noon of sunny days. Compared to non-event days, the wind speed, SO2 and O3 concentrations were higher on NPF days, whereas the temperature and relative humidity (RH) were at comparatively lower levels. The concentrations of small particles (10∼20nm) increased first, and then the larger particles (20∼50nm) concentrations increased over time. The peaks of large aerosol particle concentration were lower than that of small ones and the average growth rate (GR) of the newly formed aerosol particles was 3.58nm h-1. SO2 concentration peaked before nucleation mode particle number concentration reached to its maximum. SO2 participated in the particles nucleation as a kind of precursor and influenced the growth of newly formed particles. In our studies SO2 concentrations were found to be the main influencing factor of the aerosol particle growth rate, so the aerosol particle growth rate was higher with higher concentration of SO2. The basis for observation and parameterization schemes in this work will contribute to the database enrichment and model simulations of nucleation mode particle growth over this region.