Ice Core Archives of Mineral Dust - Mineral Dust: A Key Player in the Earth System - page 463

18.3.1.1.3 Coastal and Regional Variability

Several dust records are available from coastal zones of Antarctica, allowing
comparisons between different sectors of Antarctica and the identification of
variable dust inputs to different parts of Antarctica on centennial timescales.
Delmonte et al. ( 2004b ) reported deglacial dust records from Dome B, Dome C and
Komsomolskaya (KMS) and identified a regional oscillation in dust size fraction.
This was interpreted as a poleward migration of the Antarctic polar vortex, leading
to less subsidence of upper-atmosphere air masses at the more-coastal locations
of Dome C and KMS. In all three records, a “pre-Holocene dust minimum” was
observed between 11.3 and 12.1 ka ago. Rather than dust, Fischer et al. ( 2007a )
evaluated reported nssCa 2C fluxes at EDML, finding them to be approximately
3 times greater than those at EDC. This difference was attributed to the greater
proximity of EDML to dust sources in southern South America compared to
EDC. Using a simple box model of dust transport, the glacial-interglacial dust flux
variability observed at EDML and EDC was attributed to changes in the strength
of southern South American dust sources, rather than changes in the efficiency of
atmospheric transport pathways.
Dust records from Talos Dome, a coastal site in Northern Victoria Land, feature
some important differences to those from the East Antarctic Plateau. The Talos
Dome dust record shows greater dust concentrations during the Holocene, attributed
to local sources that were exposed since the deglaciation (Delmonte et al. 2010 ).
Over the Holocene, these local source inputs slowly diminished due to changes in
local atmospheric circulation resulting from the retreat of the Ross Ice Shelf (Albani
et al. 2012 ) and the possible exhaustion of local dust sources. The Talos Dome dust
record does not feature the pre-Holocene dust minimum observed in central East
Antarctica, further hinting at different deglacial tendencies across Antarctica and
especially in the coastal regions.

18.3.1.1.4 Recent Dust Flux Variations

The few studies available indicate that Antarctic dust fluxes have increased over
the twentieth century. McConnell et al. ( 2007 ) determined Al fluxes in an ice
core from James Ross Island, finding aluminosilicate dust fluxes to have increased
since 1832, from approximately 12 (1832-1900) to 27 (1960-1991) mg/m 2 /y.
This confirmed two low-resolution dust particle records from West Antarctica
(Thompson et al. 1994 ), showing stable dust concentrations between 1500 and 1900,
and an approximate doubling over the twentieth century. Vallelonga et al. ( 2004 )
also observed a twentieth-century doubling in mineral dust concentrations (based
on a suite of 11 crustal and marine elements) in a 500-year ice core record from
Law Dome.