Dr Tas van Ommen, Australian Antarctic Division Project Leader, Climate Variability and Change 03 6226 2981 tas.van.ommen@acecrc.org.au

Project Overview

The Climate History Project provides records of past climate from ice cores and ocean sediment cores and aims to improve understanding of underlying climate processes, forcings and natural climate variability.

Records of past climate serve as important tests of climate models when run as hindcasts: tests that serve to improve confidence in model forecasts. Past climatic data are also needed as boundary conditions (e.g., volcanic forcing and past greenhouse gas changes) for model simulations of climate changes. In addition to improved confidence in model forecasts (i.e., reduced prediction uncertainties), past climate research results in concrete data on how climate has varied on timescales beyond the instrumental record.

For example, processes such as the El Niño Southern Oscillation (ENSO), and the interactions between the mid-latitude high pressure belt, westerly winds and Antarctic Circumpolar Current (ACC) are known to have impacts on Australian climate, but understanding of their long-term patterns is incomplete. Furthermore, the extent to which these and other processes are shifting under the influence of climate change is uncertain. Such understanding of longer-term variability and change is needed for planning responses to future climate changes. This project provides measures of variability and change from records that have a particular geographical focus on the Southern Ocean and Australian region.

Project Objectives:

• To improve understanding of climate connections between East Antarctica and the Southern Ocean and mid-latitudes, including links with El Niño Southern Oscillation.
• To measure changes in drivers of past climate, including the roles of solar variability and volcanic activity.
• To identify new proxies for climate processes.
• To produce basic high resolution time series of key features of Holocene climate including precipitation and accumulation, chemical and isotopic tracers.
• To reconstruct past climate indices (e.g., sea ice extent, Southern Annular Mode).