Fig. 3. Ultrafine particle growth and losses.
a Particle size distribution (PSD) measured with a neutral cluster and air ion spectrometer (NAIS) with the indication of the fitted mode diameter used for growth rate calculation. The black hatched region indicates a period influenced by pollution from the ship. b Concentrations of iodic and sulfuric acid together with visibility. Grey shaded areas indicate fog periods. c Growth rate (GR) measurements for the entire campaign as a function of the mean diameter mode during the event. The blue marker shows the measured growth rate obtained by fitting the mode diameter (the error bars represent the 95% confidence intervals from the fitted slope). The bar plot shows the estimated growth rate based on the mean mode diameter and the concentration of sulfuric and iodic acid44. The black lines are the error bars due to the uncertainty of sulfuric and iodic acid concentration. The red dashed bars show the predicted growth rate when considering also the charge enhancement factor (EF) derived from Stolzenburg et al.45 Since for the last three events iodic and sulfuric acid measurements are not available, we report only the measured growth rates.