Centennial mineral dust variability in high-resolution ice core data from Dome C, Antarctica
Ice core data from Antarctica provide detailed insights
into the characteristics of past climate, atmospheric
circulation, as well as changes in the aerosol load of the
atmosphere. We present high-resolution records of soluble
calcium (Ca2+), non-sea-salt soluble calcium (nssCa2+),
and particulate mineral dust aerosol from the East Antarctic
Plateau at a depth resolution of 1 cm, spanning the past
800 000 years. Despite the fact that all three parameters are largely dust-derived, the ratio of nssCa2+ to particulate dust is dependent on the particulate dust concentration itself. We used principal component analysis to extract the joint climatic signal and produce a common high-resolution record of dust flux. This new record is used to identify Antarctic warming events during the past eight glacial periods.The phasing of dust flux and CO2 changes during glacialinterglacial transitions reveals that iron fertilization of the Southern Ocean during the past nine glacial terminations was not the dominant factor in the deglacial rise of CO2 concentrations.
Rapid changes in dust flux during glacial terminations
and Antarctic warming events point to a rapid response
of the southern westerly wind belt in the region of southern
South American dust sources on changing climate conditions.
The clear lead of these dust changes on temperature
rise suggests that an atmospheric reorganization occurred in
the Southern Hemisphere before the Southern Ocean warmed
Authors: Lambert, F., Bigler, M., Steffensen, J. P., Hutterli, M., Fischer, H.