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Figure 1: Examples of some of the properties measured in the GISP2 core presented as a 50-year smoothed version of the original series (in some cases the original resolution is biannual) covering the period AD1000-AD1989. Oxygen isotopes where is parts per thousand (modified from Grootes et al. [1993]); accumulation rate (modified from R. B. Alley et al., unpublished manuscript, 1994 and Meese
[4]

 
Figure 1: Figure 1 continued.

et al. [1994a,b]); CO (modified from Wahlen et al. [1991]); ions (modified from Mayewski et al. [1993a]); particles (G. R. Mershon, personal communication, 1994); MSA (from Saltzman and Whung, unpub.); hydrogen peroxide (from Drummey et al. [1995]); and Icelandic temperatures and sea ice (modified from Bergthorsson [1969]). Figure taken from GISP2 Investigators [1993].

 
Figure 2: A multi-parameter view of the period 10-18 kyr BP. Stable isotopes (modified from Grootes et al. [1993]); accumulation rate (modified from Alley et al. [1993]); calcium (modified from Mayewski et al. [1993c, 1994b]); methane (modified from Chappallez et al. [1993]); ammonium (modified from Mayewski et al. [1993c]).

 
Figure 3: The GISP2 calcium record in ppb (modified from Mayewski et al. [1994b] and Bender et al. [1994]), with dating based on Meese et al. [1994a,b], Sowers et al. [1993], and Bender et al. [1994]. Increased levels of calcium represent dustier, cooler periods, while decreased calcium levels represent milder periods with less intense atmospheric circulation.