DSC Seminar #7 | Global ocean modelling in the Deep South Challenge

ocean wave

Wednesday 30 May, 12.30–1.30pm
With Erik Behrens (NIWA)

The oceans are the largest ecosystem on our planet, with complex physical and bio-geochemical interaction between the atmosphere, sea ice and ice shelves. Oceans are the main storage for human-produced heat and carbon. At the same, oceans have the ability to redistribute heat and carbon both across large distances and over time, which makes them the key component in the climate system. 

Our understanding of the oceans has improved substantially in recent decades, thanks largely to satellite and Argo observations (a global network of ocean floats). Models are still (and will always be) necessary to fill data gaps, to put observations into a larger spatial and temporal context, and to forecast future changes. 

The ocean model in our New Zealand Earth System Model (NZESM) is based on the NEMO and MEDUSA models, and can be used to model past, present and future conditions. 

This presentation will include a brief introduction into the NEMO model and to the model configuration (eORCA1) which is used in NZESM. It will also focus on recent NEMO applications and scientific research using nesting (grid refinement) techniques within NEMO. Within the Deep South Challenge, a new model has been developed which uses nests to obtain a 1/15° resolution over the Ross and Amundsen Seas. In this way we can investigate how model resolution influences the spreading of Antarctic Bottom Water from these regions.

Finally, we will be presenting results on the recent NZ marine heat wave, demonstrating that subsurface heat transport plays an important role in the years-to-decades occurrence of marine heat waves in the Tasman Sea. 

About the presenter
Erik Behrens (NIWA) studied physical oceanography in Kiel, GEOMAR, Germany and obtained his Diploma in 2008 by investigating the Indonesian Throughflow. He continued as a PhD at the GEOMAR, researching the effects of increased melting of the Greenland ice sheet on the Atlantic Ocean. He then began work at NIWA, where his research focus has shifted towards the Southern Ocean and investigating coupled earth system models.


Virtual hui: 

To participate via ZOOM, please register here first (and download Zoom to your computer).

Physical hubs: Please note, all NIWA visitors must sign in on arrival.

NIWA Wellington:
Conference Room
Our speaker will be presenting from this hub.

NIWA Auckland:
Seminar Room

NIWA Lauder:
Computer Room

NIWA Hamilton:
C-Block Meeting Room

NIWA Christchurch:
Tekapo Seminar Room

Victoria University of Wellington:
LABY Lecture Theatre 118

University of Canterbury:
Room 411, Law Building

University of Otago:
Room 229, Science III building

We encourage you to set up your own hub and bring friends and colleagues together to participate in the seminar. Please let us know if you do set up your own hub.

Email: alex.keeble@niwa.co.nz