Chemical composition of marine aerosols of the 26th Chinese National Antarctic Research Expedition

The ionic compositions of aerosol samples collected during the 26th Chinese National Antarctic Research Expedition were analyzed and the sources of ions were distinguished.Cl-,Na+,SO2-4,NO-3,and Mg2+were the most abundant ionic components in the marine aerosols.Cl- and Na+ contributed over 70％ in the total ionic composition,indicating the sea salt is still the primary composition in marine aerosols,followed by the sulfate as the secondary ionic component existed as NH4NO3,NH4HSO4,(NH4)2SO4.The maximal sea salt concentrations were found at around 40°S and could be attributed to greater winds.The concentrations of methane sulfonic acid (MSA) appeared increasing trend from the low to high latitudes,possibly caused by lower temperature in air and higher marine biological processes in the marginal waters in Antarctica.The correlation and factor analyzes were used to investigate possible sources of these ions.Cl-,Br-,Na+,K+,Mg2+ and Ca2+had predominantly marine sources; while F-,NO-3 and NH+4 had mostly anthropogenic sources; MSA had marine biogenic sources.The concentrations of SO2-4 were influenced by both marine and anthropogenic sources.