NOAA/WDS Paleoclimatology - Santa Barbara Basin 640 Year Alkenone Sea Surface Temperature

Analyses for C37 alkenones (U37K') and total organic carbon (TOC) in a varved core from the depocenter of the Santa Barbara Basin (34deg13.5'N, 120deg01'W, 590 m water depth) have been made on an approximately 1-2 year basis from A.D. 1440 to 1940. The U37K'-based sea surface temperature (SST) record oscillates around 15.5C with an amplitude of less than 3C at approximately interannual, decadal, and centennial frequencies. Historical El Nino/Southern Oscillation (ENSO) events are matched only partially by warmer U37K' SSTs. Three records: our SST, a published Pacific coral d18O, and a published tree-ring temperature anomaly from the California valleys, show no evidence of colder temperatures during the Little Ice Age (ca. 1500 to 1840 A.D.). Significantly, there is a strong centennial-scale cyclicity in the U37K' SST record which approaches 1C in amplitude. TOC burial and alkenone fluxes are largely controlled by sedimentation rate as expressed in varve thickness.