FIGURE 6-2 Two composite isotopic records from low latitudes and two isotopic records from single locations on the polar ice sheets. Top: Record for central Greenland (GISP2 site), converted to temperature by calibration against borehole temperatures. Second from top: Composite record (normalized to mean and standard deviation) for four ice cores from Tibet. Third from top: Composite record (normalized to mean and standard deviation) for three ice cores from the equatorial Andes. Bottom: Normalized record (deuterium) from Taylor Dome, Antarctica. In each plot, data are shown as point measurements and a smoothed version is superimposed for clarity of trends. The central Greenland and Taylor Dome series are smoothed using a 100-year triangular filter, while the composite series uses a 50-year triangular filter. SOURCES: Data from Cuffey and Clow (1997), Thompson et al. (2003, 2006), and Steig et al. (2000).