ENSO/SAM interactions during the middle and late Holocene

• Published in: The Holocene
• Main Authors: Gomez, Basil, Carter, Lionel, Orpin, Alan R., Cobb, Kim M., Page, Michael J., Trustrum, Noel A., Palmer, Alan S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 2011
• Subjects: Paleontology; Earth-Surface Processes; Ecology; Archeology; Global and Planetary Change; Pacific; New Zealand; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1177/0959683611405241; http://journals.sagepub.com/doi/pdf/10.1177/0959683611405241

A new chronology of large magnitude rainfall events derived from the continuous high-resolution Lake Tutira storm sediment record covers the last 6800 years and provides the first insight into changes in El Niño-Southern Oscillation (ENSO) teleconnections to the higher southern latitudes to be obtained from New Zealand. Synthesis with independent paleoclimate records from the tropical Pacific and Antarctica also reveals a millennial-scale waxing and waning of the teleconnections that were not visible in the narrow historical window previously used to view interactions between ENSO and the Southern Annular Mode (SAM). Consistent with modern ENSO behaviour, we find teleconnections to the Southwest Pacific varied throughout the middle and late Holocene, depending on the strength and phase of ENSO and the phase of the SAM. We suggest that precession-driven changes in the seasonal cycle of solar radiation exert a first-order control on the interaction between the two climate modes. Consequently, their present status may neither be indicative of conditions that prevailed earlier in the Holocene, nor of those that might be associated with future climate changes in the Southern Hemisphere extratropics.