Forcing of Atlantic Equatorial and Subpolar Millennial Cycles by Precession
Abundance cycles of the marine alga Florisphaera profunda centered on a period of 7600 carbon-14 years (8400 calendar years) are present in high-resolution records from the equatorial Atlantic spanning 0 to 45,000 years ago. These cycles correlate with Heinrich events 1 through 5, which document rapid changes in continental ice melting around the subpolar North Atlantic. These variations in F. profunda are a direct response to modulation in zonal wind-driven divergence produced by a precessional component of orbital variation during a time of reduced eccentricity modulation.
McIntyre
A
Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA.
Molfino
B