title: Sulphate-climate coupling over the past 300,000 years in inland Antarctica.
abstract: Sulphate aerosols, particularly micrometre-sized particles of sulphate salt and sulphate-adhered dust, can act as cloud condensation nuclei, leading to increased solar scattering that cools Earth's climate. Evidence for such a coupling may lie in the sulphate record from polar ice cores, but previous analyses of melted ice-core samples have provided only sulphate ion concentrations, which may be due to sulphuric acid. Here we present profiles of sulphate salt and sulphate-adhered dust fluxes over the past 300,000 years from the Dome Fuji ice core in inland Antarctica. Our results show a nearly constant flux of sulphate-adhered dust through glacial and interglacial periods despite the large increases in total dust flux during glacial maxima. The sulphate salt flux, however, correlates inversely with temperature, suggesting a climatic coupling between particulate sulphur and temperature. For example, the total sulphate salt flux during the Last Glacial Maximum averages 5.78 mg m(-2) yr(-1), which is almost twice the Holocene value. Although it is based on a modern analogue with considerable uncertainties when applied to the ice-core record, this analysis indicates that the glacial-to-interglacial decrease in sulphate would lessen the aerosol indirect effects on cloud lifetime and albedo, leading to an Antarctic warming of 0.1 to 5 kelvin.
authors.affiliation: Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819, Japan. iizuka@lowtem.hokudai.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Iizuka
authors.forename: Ryu
authors.initials: R
authors.lastname: Uemura
authors.forename: Hideaki
authors.initials: H
authors.lastname: Motoyama
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Suzuki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Miyake
authors.forename: Motohiro
authors.initials: M
authors.lastname: Hirabayashi
authors.forename: Takeo
authors.initials: T
authors.lastname: Hondoh