Ice Core Archives of Mineral Dust - Mineral Dust: A Key Player in the Earth System - page 471

Fig. 18.8 Individual size
distributions by volume from
different climatic periods
along with lognormal fits. a :
1,831.50-1,833.15 m (LGM);
b : 2,075.70-2,077.35 m
(Stadial 9); c :
2,121.90-2,123.55 m
(Interstadial 10); d :
1,460.25-1,461.90 m
(Preboreal). Indicated is the
position of the mode and the
uncertainty of the fit [ a :
(1.73 ˙ 0.02) m; b :
(1.65 ˙ 0.06) m; c :
(1.54 ˙ 0.05) m; d :
(1.21 ˙ 0.11) m]. From
Ruth et al. ( 2003 )

particles. Gassó et al. ( 2010 ) also presented a combined study of dust collected from
Antarctic air, satellite observations and modelling, although dust particle sizes were
not presented. Such combined studies offer the best way forward to quantifying and
interpreting changes in particle sizes reported for Antarctic ice.

18.5.2 Greenland

The earliest observations of size distributions of insoluble particles in Greenland ice
showed a log-normal distribution similar to that reported for Antarctica. Thompson
( 1977 ) observed a greater proportion of coarse particles ( D v >1.65 m) in Holocene
ice from Camp Century ice core, compared to LGM ice. Similar to the situation
for Antarctica, more accurate measurements of DYE-3 and GRIP ice by Steffensen
( 1997 ) found the opposite result, of a small decrease in D v from LGM (2.06 m) to
Holocene (1.84 m) conditions. Most recently, Ruth et al. ( 2003 ) used laser particle
counter data to confirm the shift toward a larger mode in the more-dust climatic
periods of the LGM and late Greenland stadials (1.6-1.7 m) compared to the
Preboreal and Greenland interstadials (1.2-1.5 m). These results were interpreted
as being indicative of a faster atmospheric transport time during the LGM rather
than changes in deflation sources or dust characteristics (Fig. 18.8 ).