Talk by Dr. Tessa Vance - NOW on 9/4 15 – Københavns Universitet

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Talk by Dr. Tessa Vance - NOW on 9/4 15

Reconstructing Pacific decadal variability from the Law Dome ice core

Abstract
Decadal scale SST oscillations in the Pacific significantly influence rainfall variability and drought risk across and beyond the Pacific region. Understanding long-term decadal SST behavior in the Pacific is necessary to assess past and future climate, particularly drought risk. However, short instrumental records through much of the Pacific region, in particular the South Pacific, make such assessments difficult.

A new reconstruction of Pacific decadal variability covering the last millennium has been produced from the Law Dome ice core, a high snow accumulation site in East Antarctica. The Law Dome ice core samples (at sub-annual resolution) a broad mid-latitude swathe of the Indian and South West Pacific region. This region exhibits wind speed and direction anomalies that are coherent with the phase of the Interdecadal Pacific Oscillation (IPO), an index measuring the decadal-scale Pacific SST state. 

This is the first millennial length IPO reconstruction and is based on the annual accumulation (snowfall) and sub-annual sea salt (wind proxy) records from Law Dome. Importantly, this new IPO reconstruction will help with assessing climate risk over the longer term in the wider Pacific Basin, particularly in the data-sparse Southern Hemisphere.

Tessa R. Vance1, Jason L. Roberts1,2, Chris T. Plummer3, Anthony S. Kiem4, Tas D. van Ommen1,2

1. Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Australia.
2. Department of the Environment, Australian Antarctic Division, Hobart, Australia.
3. Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia.
4. Faculty of Science & Information Technology, University of Newcastle, Callaghan, Australia.