Wind-dependent sea salt aerosol in a Western Pacific coastal area

Five-year PM10 data sets from three monitoring stations at a coastal city of China have been employed, together with surface pressure maps, wind data and backward trajectory analyses to investigate the relationship between sea salt concentration (C) and wind speed (U). A log-linear variation of sodium ion concentration with wind speed has been obtained (i.e. ln C=aU+b), only under the influence of the Asian summer monsoon, where U is the synoptic wind speed rather than the local wind speed. The values a and b fall into the range of values from previous studies, although the background loading b is relatively small, since the previous studies were carried out on ships or very near to the coastal line rather than in an urban area. The sea salt concentrations are mainly influenced by the production mechanism rather than the transport process.