The New Zealand Earth System Model (NZESM) is being used to study NZ's oceans, atmosphere, and land to better understand how climate change is affecting these systems, as well as how they affect each other. Image: PublicDomainPictures, Pixabay.

Getting closer to more accurate climate predictions for New Zealand

"Researchers will be using this model for ground-breaking research."

The Challenge:

To build more customised and unique models specific to New Zealand's climate systems.

The Solution:

Researchers from the Deep South National Science Challenge worked with NeSI's computational science team to enhance functionality of the New Zealand Earth System Model.

The Outcome:

An improved Earth System Model to map climate change, allowing government and industry to better plan for New Zealand's future climate.


Dr. Erik Behrens is an Ocean Modeller at the National Institute of Water & Atmospheric Research (NIWA) in Wellington. There, he works with climate scientist, Dr. Jonny Williams on the New Zealand Earth System Model (NZESM), improving climate change projections for New Zealand.

The NZESM models the oceans, atmosphere, and land to better understand how climate change is affecting these systems, as well as how they affect each other. It is a central part of the Deep South Challenge to understand how the Earth System changes, around New Zealand and in Antarctica. The Deep South, with NZESM as its main tool, is one of a handful of similar projects around the world – including the United Kingdom and Norway – aimed at giving government and industry the information needed to prepare for the planet’s changing climate.

The OASIS customisation for the NZESM was a vital part of continuing this work. Through NeSI’s Consultancy Service, Chris Scott and Wolfgang Hayek carried out these modifications to OASIS, in collaboration with Dr. Behrens, and enhanced the functionality of the NZESM. This was a critical step in the development of the NZESM and makes it better tailored to New Zealand’s needs.

“It’s an advancement. There’s an additional switch that enables an essential feature of the NZESM, which makes it unique. Without it, the NZESM wouldn’t have run and could not provide accurate climate predictions for New Zealand,” says Dr. Behrens.

The OASIS coupler is a central part of the NZESM. It acts as a communicator for the different modelling programs to speak with each other. With these different modelling programs simulating oceans, atmosphere, ice sheet models and vegetation, researchers can build a large-scale view of how the world is changing and how it will look in the future.

“The coupler is a critical part for making all the different aspects of the NZESM communicate. It lets us have a fully covered geophysical model of the entire Earth, but it needed to be upgraded to allow the model to run.”

The NZESM runs on the supercomputer, Maui, hosted at NIWA in Wellington. To get an idea of the massive amount of computation required by the model, often 1,500 computer processors are needed for one simulation.

To modify OASIS, Dr. Behrens took advantage of NeSI’s Consultancy Service, which provides scientific programming expertise and support to NeSI users.

“I was positively surprised how quickly the work was performed,” said Dr. Behrens. “Everything went really smoothly and NeSI did a great job providing good service on time. NeSI provided the solution and ran test cases to prove the upgrade was working successfully.”

Now that the modifications are complete, the improved functionality will support a wide variety of climate research projects. The ability to mesh data from different ecosystems and weather systems will show researchers how these seemingly separate systems work together, and how they will change with the climate in the future.

“The NZESM is a community project. With this upgrade we have an exciting tool with which to study the climate. It will have a huge impact and is tailored to New Zealand’s needs. Researchers will be using this model for ground-breaking research – research that couldn’t be done without the OASIS upgrade.”

With this holistic view, researchers will be able to help determine where the best policy intervention spots might be for climate change and how decisions in one ecological system affect others. It’s a project NeSI is proud to partner in, providing the computational science expertise and resources needed to make interdisciplinary projects like the NZESM possible.

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