Ice cores

Ice core records are crucial to improving our knowledge about climate variability and global warming.

Ice core from Greenland

New Zealand’s future economic and social development, environmental sustainability, and infrastructural planning relies critically upon the accurate assessment of the impact of 'global warming' in our sector of the planet. Future climate change is a result of both natural variability and anthropogenic influence. A major problem is that natural variability can involve large, abrupt switches in Earth’s climate, and the cumulative effects of anthropogenic influences remain highly uncertain.

Ice core records provide an annual-scale, 'instrumental-quality' baseline of atmospheric temperature and circulation changes back many thousands of years. Their analysis has allowed human-induced warming on a global scale to be extracted from the background climate state and the fundamental non-linear behaviour of the climate system at inter-decadal to century-scale (e.g. ENSO) to be evaluated.

The scientific goal of the Victoria University/ GNS Science ice core programme is to improve our understanding of the major Southern Hemisphere climate drivers causing high frequency climate variability. These are in particular the El Niño Southern Oscillation, the Antarctic Oscillation, and the Antarctic Circumpolar Wave, as well as feedback mechanisms causing abrupt climate change, such as changes in sea ice cover or ice shelf instability. Many of these climate drivers operate on rapid time scales (sub-decadal) and potentially respond to longer term forcings (centennial to millennial).

It is therefore important to obtain high resolution (sub-annual) records that can reliably capture the high frequency variability of these drivers from sites that are particularly sensitive to their influence, while at the same time providing a long enough record to investigate superimposed longer-term trends.

We have identified key locations from low elevation, coastal sites. These sites are particularly climate sensitive, as they capture tropospheric climate variability and in general have a higher snow accumulation rate than sites from the Antarctic interior. This makes these sites ideal when investigating abrupt and rapid climate change.

Please contact Nancy Bertler for more information about our ice core research.