Artificial primary marine aerosol production: A laboratory study with varying water temperature, salinity, and succinic acid concentration
Primary marine aerosols are an important component of the climate\nsystem, especially in the remote marine environment. With diminishing\nsea-ice cover, better understanding of the role of sea spray aerosol on\nclimate in the polar regions is required. As for Arctic Ocean water,\nlaboratory experiments with NaCl water confirm that a few degrees change\nin the water temperature (T-w) gives a large change in the number of\nprimary particles. Small particles with a dry diameter between 0.01 mu m\nand 0.25 mu m dominate the aerosol number density, but their relative\ndominance decreases with increasing water temperature from 0 degrees C\nwhere they represent 85-90% of the total aerosol number to 10 degrees\nC, where they represent 60-70% of the total aerosol number. This effect\nis most likely related to a change in physical properties and not to\nmodification of sea water chemistry. A change of salinity between 15 g\nkg(-1) and 35 g kg(-1) did not influence the shape of a particle number\nsize distribution. Although the magnitude of the size distribution for a\nwater temperature change between 0 degrees C and 16 degrees C changed,\nthe shape did not. An experiment where succinic acid was added to a NaCl\nwater solution showed, that the number concentration of particles with\n0.010 mu m< D-p< 4.5 mu m decreased on average by 10% when the succinic\nacid concentration in NaCl water at a water temperature of 0 degrees C\nwas increased from 0 mu mol L-1 to 94 mu mol L-1. A shift to larger\nsizes in the particle number size distribution is observed from pure\nNaCl water to Arctic Ocean water. This is likely a consequence of\norganics and different inorganic salts present in Arctic Ocean water in\naddition to the NaCl.