Professor Rack and his team, which includes research scientist Dr Daniel Price from the UC School of Earth and Environment, have been awarded a three-year $929,000 Marsden Fund grant from Royal Society Te Ap膩rangi for the project. It is a collaboration between UC, Lincoln Agritech, the Alfred Wegener Institute for Polar and Marine Research (AWI) in Germany, Australian Antarctic Division, NASA, and ETH Zurich University.
The survey will be carried out in late 2024 in the Ross Sea and Western Pacific areas of Antarctica using a fixed-wing DC3 aircraft provided by Antarctica New Zealand in collaboration with the Australian Antarctic Division. An 鈥楨M Bird鈥 - an electromagnetic induction device provided by a collaborator from AWI - will be suspended 80 metres under the aircraft to measure the thickness of the ice below.
For this project, it will be combined with a built-in snow radar, developed with collaborators at Lincoln Agritech and integrated with the EM Bird system at UC and AWI. In combination, the technology can simultaneously measure ice thickness and the depth of the snow layer on top.
It鈥檚 an important breakthrough to be able to separate the thickness of the snow and ice, Professor Rack says.听
鈥淔or the first time we will be able to directly assess the thickness and volume of complex coastal sea ice. We theorise this type of ice is a major factor in the global climate system - if it is changing, then there will be big consequences for our planet.鈥
Sea ice helps sustain Antarctic 鈥榖ottom water鈥, which is the deepest, coldest and densest ocean water. This bottom water helps remove carbon dioxide from the atmosphere, storing it on the ocean floor for a long time. It also helps circulate the world鈥檚 oceans.
鈥淭he more sea ice is out there, the more Antarctic bottom water is created, so it鈥檚 a critical part of oceanic and atmospheric circulation with huge global impacts,鈥 Professor Rack says.听听
Vast areas of Antarctic sea ice cover up to 20 million square kilometres in winter, reflecting sunlight and mitigating its warming effects on sea temperatures.
Sea ice trends are poorly understood because satellites can only reliably map their area. Only a few thickness measurements are taken from the ground every year, and they cover a relatively small area.
鈥淪ince the late 1970s, we鈥檝e observed an increase in the area of coastal sea ice in Antarctica, which is the opposite of what one would expect,鈥 Professor Rack says. 鈥淥nly very recently have we seen a decline, but also much more variability. We need to know more about the thickness of the ice and its overall mass to understand these changes.鈥
The data collected will be used to develop a tailored satellite-derived ice thickness product for Antarctica鈥檚 coastal region and will also provide observational datasets for computer simulations that will allow better forecasting.
- 罢丑别听New Zealand Sea Ice Symposium 2023: Building Aotearoa鈥檚 Sea Ice Science Vision听will be held at the University of mini传媒 February 13 -14. The national event is a 'think tank' for strategies to progress sea ice science in New Zealand.
