TY - JOUR AU - Hill-Falkenthal, J. PY - 2013// TI - Seasonal variations in 35S and Δ17O of sulfate aerosols on the Antarctic plateau T2 - J. Geophys. Res. Atmos. JO - Journal of Geophysical Research: Atmospheres KW - The first reported seasonal Δ KW - 17O anomaly in sulfate aerosols and measurements of radioactive 35SO42− KW - activities collected from Dome C KW - Antarctica KW - are reported. Δ KW - 17O values exhibit minima during summer (as low as 0.91‰) when tropospheric oxidation patterns are dominated by OH/H2O2 mechanisms. Significant enrichment during autumn and spring is observed (up to 2.40‰) as ozone oxidation increases in the troposphere relative to summer and both stratospheric sources and long-range transport become more significant to the total sulfate budget. An unexpected decrease in Δ KW - 17O is seen as winter progresses. This decline is concluded to potentially arise due to a reduction in vertical mixing in the troposphere or linked to variations in the long-range transport of sulfur species to Antarctica. 35SO42− KW - activities exhibit maxima during summer (up to 1219 atoms 35S/m3) that correlate with the peak in stratospheric flux and minima during winter (as low as 146 atoms 35S/m3) when the lack of solar radiation substantially reduces photochemical activity. It is shown that 35S offers the potential to be used as an additional tracer to study stratospheric and tropospheric interactions and is used to estimate stratospheric input of sulfur (combination of SO2 and SO42− KW - ). Stratospheric sulfur input produces maxima during summer/autumn with an upper limit of 5.5  KW - ng/m3 and minima during winter/spring with an upper limit of 1.1  KW - ng/m3. From these results KW - it is concluded that the variation in Δ KW - 17O is more reliant upon shifts in tropospheric oxidation mechanisms and long-range transport than on changes in the stratospheric flux. SN - 2169-8996 UR - http://dx.doi.org/10.1002/jgrd.50716 N1 - exported from refbase (http://publi.ipev.fr/polar_references/show.php?record=4471), last updated on Wed, 03 Jul 2024 14:06:30 +0200 ID - Hill-Falkenthal2013 ER -