that is inherent in such processes. The approximately 14-year circulation period of the subpolar gyre is plainly one such control, but the decadal regimes in southeastern U.S. air temperature shown in Figure 11, the 6.7-year spectral maximum in the North Atlantic oscillation index (Rogers,
1984), the multi-year advective time lag of ice drift from the Beaufort Sea to Greenland and Labrador (Mysak and Power, 1991; Mysak and Manak, 1989) plainly have the potential to lend a degree of periodicity to the process. Conceptual models for these periodic anomalies—some of great complexity (see Figure 3 of Mysak and Power, 1991)—have been proposed (see also Darby and Mysak, 1993; Ikeda, 1990). Under this rationale the Great Salinity Anomaly was merely a more obvious, high-amplitude iteration of a regular event.
To demonstrate a global role for Denmark Strait exchanges, there can be few more eloquent illustrations than Figure 16 (from Charles and Fairbanks, 1992), in which the d13C history in benthic forams from the sea-floor sedi-