An 1800-Year Periodicity in Oceanic Tidal Dissipation as a Possible Contributor to Millennial-Scale Global Climate Change

C.D. Keeling (University of California, San Diego, CA 92093-0220; ph. 619-534-4230; fax 619-534-8814; Internet: cdkeeling@ucsd.edu); T.P. Whorf (University of California, San Diego, CA 92093-0220; ph. 619-534-4230; fax 619-534-8814; Internet: twhorf@ucsd.edu);

Recent interpretations of satellite altimetry measurements indicate that as much as half of the energy dissipated in the production of the thermocline of the open ocean may be produced by the action of the oceanic tides. If so, sea-surface temperatures may cool during episodes of strong tidal forcing on time scales from fortnightly to hundreds of thousands of years. We explore the possibility that distinct 1800-year repetitions of strong tidal forcing in phase with the Little Ice Age may be a factor in producing the millennial-scale variations seen in ocean sedimentary and ice-core records.