ACE-1 - Southern Hemisphere marine aerosol characterisation experiment

This is likely to have resulted from inclusion of continental air from western parts of the Australian mainland in the baseline sector winds. Although aerosol-bound sulfur species were generally near their normal concentrations across the ACE 1 area, the overall pattern including atmospheric dimethylsulfide suggest slightly higher than usual sulfur species levels in the southern part of the region and lower concentrations in the northern part during November.

This could be related to changes in marine biogenic productivity, air-sea exchange, or atmospheric removal. In December, the changing long wave pattern brought an increase in south and southwesterly flow over the entire region. The baseline sector became less affected by continental species, but it appears that the colder conditions brought by this pattern have led to lower than usual atmospheric concentrations of biogenic species, as the region went into one of the coldest summers on record.