The Stormy Seas project

Does climate change affect the position of the Subtropical Front around New Zealand?

The Subtropical Front (STF) is the boundary between cold subantarctic water masses of the Southern Ocean to the south and warm subtropical water masses of the South Pacific to the north. The Subtropical Front is important for New Zealand as it is characterized by enhanced biological productivity making it an important area for New Zealand Fisheries. The Subtropical Front also affects the climate of New Zealand as it is forced south of New Zealand and bathes the south island in warm water.

In this Marsden funded project we will be developing a high resolution model for the New Zealand region. This model is based on a global model NEMO. The high resolution mesh for the New Zealand region will sit within the lower resolution global NEMO model. Each grid in the New Zealand region will represent just a few kilometres, which will allow us to simulate the oceanic circulation around New Zealand more precisely and to resolve small oceanographic features such as eddies.

We will use this model to perform climate change simulations, where we modify the position and strength of the westerly winds and/or sea level to simulate past, present and future conditions around New Zealand. By changing these environmental parameters and comparing the different simulations, we will assess how the Subtropical Front has responded in the past and will respond in the future to a changing climate.

This three year research project is led by Dr. Erik Behrens (NIWA) and brings together international experts in ocean modelling from Australia (Prof. Matthew England and Prof. Andy Hogg) and Germany (Prof. Claus Böning) and is supported by Dr. Helen Bostock (NIWA).