Atmospheric trace metals （Cu, Zn, Cd, Pb, Fe, V, and Cr）, As, A1 and Na in marine aerosols were studied over the Southern Ocean during the 28th Chinese National Antarctic Research Expedition. Fe was the most abundant of the analyzed trace metals, with an average concentration of 28.824 ng.m3. V and Zn concentrations were also high, and their average concentrations were 5.541 ng.m^3 and 2.584 ng.m^-3, respectively. Although sea spray significantly influenced the marine aerosol particles measured （Na had the highest concentrations of the analyzed elements, with an average concentration of 2.65 μg.m^-3）, multivariate analyses （enrichment factor and principal components analysis） indicated that most of the elements were not associated with oceanic sources. Over the Southern Ocean, Fe, Cd, As, AI and Cr in the aerosols mainly originated from crustal sources, while Cu, Pb, V and Zn originated from crustal sources and anthropogenic emissions. The enrichment factors （EFcrust） for most elements （Fe, Al, As, Cr, Cd, Cu and V） were much lower in the northern latitudes, indicating that when the sampling occurred closer to land the concentrations of these elements in aerosols were strongly affected by terrestrial crustal sources.
Observations of atmospheric methane-sulfonic acid（MSA） and non-sea-salt sulfate（nss-SO4^2-） from December 2010 to November 2011 at Zhongshan Station are presented in this paper. MSA and nss-SO4^2- average concentrations were 24.2 ± 37.9 ng·m^-3（0.5-158.3 ng·m^-3） and 53.0 ± 82.6 ng·m^-3（not detected [n.d.]） - 395.4 ng·m^-3）, respectively. Strong seasonal variations of MSA and nss-SO4^2-, with maxima in austral summer and minima in winter, were examined. The high concentrations of sulfur compounds in December may be attributed the dimethyl sulfide（DMS） emissions from the marginal ice zone, when open water near the sampling site was important in impacting the sulfur species of January and February at Zhongshan Station. In austral winter, there was almost no phytoplanktonic activity in offshore waters, and atmospheric sulfur compounds likely had long-range transport sources.
Changes in the climate of the Arctic and of the Antarctic have been of great concern to the international scientific and social communities since the release in 2007 of the Intergovernmental Panel on Climate Change Fourth Assessment Report （IPCC AR4）. Since then, many new findings have been reported from observations and research carried out in the Arctic and Antarctic during the fourth International Polar Year （IPY）. There is evidence that global warming is inducing rapid changes in the Arctic and Antarctic, in both a quantitative and qualitative sense, and that these regional changes could be used as indicators of global climate change. Declining Arctic sea ice could affect winter snowfall across much of the Northern Hemisphere by bringing harsher winters. Projections suggest that summertime Arctic sea ice will disappear by 2037. By the 2070s, the Antarctic ozone hole will recover to the level of the early 1980s, following the ban on the production of Freon earlier this century. With the loss of the shielding effect of the ozone hole, Antarctic surface temperatures will increase, ice sheets in East Antarctica will begin to melt, and the Antarctic sea ice will retreat. Therefore, sea level rise will become an increasingly serious issue this century. As sea surface temperature rises, the Southern Ocean will become less effective as a sink for atmospheric CO2 and the increase of surface CO2 will be faster than that in the atmosphere. Increased surface CO2 would lead to ocean acidification and affect ecological systems and food chains.
