The contribution of sulfuric acid and non-volatile compounds on the growth of freshly formed particles at Melpitz

Abstract

A field campaign was conducted at atmospheric research station Melpitz, near Leipzig, Germany from May 1st to May 30th 2008 in the frame of the EUCAARI (European integrated project on aerosol, cloud, climate, and air interactions) project. During this experiment, the gas-phase sulfuric acid concentrations were measured for the first time in Melpitz, which presents an opportunity to examine the contribution of sulfuric acid as well as other compounds to the growth of newly formed particles. In addition, a Twin Differential Mobility Particle Sizer (TDMPS) in conjunction with and without a thermodenuder (TD) have been used to measure continuously the particle number size distribution from 3-800 nm at Melpitz since July 2003 along with meteorological parameters and trace gases concentrations. Aerosol particles typically grew from 3 nm to 60-70 nm during a day, while their nonvolatile cores grew by 10-20 nm as well. The total particle growth rate was 3-6 nm/h, while the nonvolatile core material can explain 16-28%. According to our results, sulfuric acid can explain 9-49% of the growth while the remainder of the growth can be explained due to possibly secondary organic compounds. © 2013 AIP Publishing LLC.