Research Project

Antarctic sea ice

Targeted observation and process-informed modelling of Antarctic sea ice (TOPOMASI)

Antarctic sea ice plays a major role in the global climate system. Its presence maintains cold conditions that help sustain Antarctica’s ice sheets, and it affects the rate of global warming by changing heat uptake in the Southern Ocean. Antarctic sea ice has a significant influence on both the ocean and atmospheric components of the climate system, and sea ice extent is closely linked with weather systems over New Zealand.

Antarctic sea ice Deep South Challenge

While the rapid retreat of Arctic sea ice is alarming researchers worldwide, satellite observations show that sea ice extent has actually been increasing in the Antarctic over the past 37 years. This behaviour is seemingly at odds with global warming. The truth is that current earth system models can’t faithfully reproduce the trends in sea ice coverage, and a lack of observations has meant that the drivers of these trends are poorly understood.

(In late 2016–early 2017, total Antarctic sea ice extent actually reduced. We still don’t know if this is a reversal of the pattern or just natural variability. Regardless, it’s important we understand what is going on.)

Antarctic sea ice grows and recedes fastest at the margins. The movement of the ocean surface waves break up ice on the outer edges, while extremely cold water causes sea ice to grow closer to the continent. This project involves field experiments on sea ice around Antarctica, and modelling work, to better understand the drivers of sea ice growth and decay. Our goal is to understand these processes well enough to ensure the NZ Earth System Model (NZESM) accurately reproduces the behaviour we’re seeing in Antarctic sea ice.

This is a joint project with the ESMP programme.

This project in the media:

PROJECT TEAM

  • Patricia Langhorne

    University of Otago
  • Alison Kohout

    NIWA
  • Wolfgang Rack

    University of Canterbury
  • Craig Stevens

    NIWA
  • Mike Williams

    NIWA
  • Natalie Robinson

    NIWA
  • Greg Leonard

    University of Otago
  • Inga Smith

    University of Otago
  • Fabien Montiel

    University of Otago
  • Christian Haas

    Alfred Wegener Institute
  • Cecilia Bitz

    University of Washington
  • Stephen Ackley

    University of Texas at San Antonio

RESOURCES FROM THIS PROJECT