The Southern Ocean in a warming world

Assessing the Southern Ocean in a warming world and its influence on New Zealand’s climate

The ocean stores and transports heat and can release that heat into the atmosphere. Changes in ocean heat dominate the global energy budget, accounting for 93 percent of global energy change since the 1970s.

Wave in the southern ocean

Changes in Southern Ocean temperatures also influence weather systems reaching New Zealand, by altering the position of the southern hemisphere storm track and cyclone development. With so much energy involved, understanding how the Southern Ocean stores and transports heat is integral to understanding climate change in New Zealand.

Unfortunately, scientists don’t have enough measurements from the Southern Ocean to accurately predict how it is changing. In our project, we’re using existing oceanographic data to identify the physical processes that will have the most impact on the NZ Earth System Model (NZESM). We’re developing modelling of ocean processes, including heat storage and transport, for inclusion in the NZESM, and test the model to make sure it replicates ocean behaviour accurately.

In this way, we’re contributing to ensuring the accuracy and reliability of the NZESM, both for our region as well as globally.

This is a joint project with the ESMP programme.


This project in the media:
New Zealand's Next Top Model, New Zealand Geographic
Breaking the ice, NIWA

Research and findings:
Variability of the subtropical mode water in the Southwest Pacific, D. Fernandez, P. Sutton & M. Bowen, Journal of Geophysical Research
Composition and variability of the Denmark Strait Overflow Water in a high-resolution numerical model hindcast simulation, Erik Behrens et al, Journal of Geophysical Research
Modelling the Southern Ocean – What are the Challenges?, Erik Behrens, Deep South Symposium
Assessing Change in the Southern Ocean, Melissa Bowen, Deep South Symposium