The presentation is focused on the results obtained just in one short period between midnight of 08/17/00 and early morning of 08/18/00. Near 150 individual aerosol samples were collected and stored from that period of time. Chemical composition of aerosols in these samples was determined later in our laboratory using automated SEM/EDX single particle analysis. For this, 25 samples with near one-hour intervals were chosen for the analysis. In each tested sample 1500-2000 individual particles were analyzed for their elemental composition including detection of low-Z elements: C, N and O. The analysis revealed that for the chosen period of time sodium-containing particles comprised 50 to 70% by number of the coarse particle mode (0.7 < Dp < 2.5 micron) and 10 to 30% by number of the fine particle mode (0.2 < Dp < 0.7 micron). During the night of 08/17/00 these particles were almost pure sea salt particles, while during the day they were effectively converted mainly to sodium nitrate particles and, to a lesser extent, sodium sulfate particles. During the evening this process was stopped and the sea salt particles appeared again in the night samples of 08/18/00. Using our time-resolved collection approach coupled with the automated SEM/EDX analysis we followed in great detail the processes of both compositional and morphology changes in the sea salt particles during the sea salt/sodium nitrate conversion. The dynamics of this process fits very well with the meteorology and gas trace observations obtained from other research groups, as will be discussed.