New Zealand scientists will begin a ground-breaking project to measure Antarctic sea ice from below this coming southern summer in a bid to get a better understanding of the effects of global climate change.

University of Canterbury scientist Professor Ian Hawes will measure the thickness and biological productivity of Antarctic sea ice, using a remote underwater vehicle to understand its role in ocean circulation and the functioning of polar ecosystems.

Other than spot drilling, measuring sea ice is extremely difficult because of its inaccessibility, Hawes said in a statement Wednesday.

"Our cutting-edge project will produce accurate information on sea ice thickness and the biomass of algae growing in the ice, information which is of global significance for better understanding linkages between ice dynamics, ecosystems and climate change," said Hawes.

"Sea ice comes in two types, pack ice and fast ice. Fast ice is attached to land and is safe to access and drill holes for only part of the year. Pack ice is not attached to land, but occurs as broken up floes that can only be accessed by some ships," he said.

"This has put major limitations on where we can sample and how many samples can be obtained.

"At the same time we know that sea ice properties are variable over distances of a few meters. Information from satellites is very limited too as they can only tell us the elevation of the ice surface."

The underwater vehicle will take measurements with finer resolution over greater distances to help measure ice properties in a much more robust way.

Sea ice varies depending on its age, but scientists are expecting it to be 2 to 3 meters thick.

"We know the Arctic sea ice area and volume have been declining for some time, but Antarctic sea ice is bucking the trend, except for an area to the west of the Antarctic Peninsula," he said.

"Otherwise, Antarctic sea ice has been increasing slightly in extent and the reasons are not completely clear. It has been suggested that this may be related to shifts in wind patterns or freshening of the surface of the ocean due to increased ice melting and precipitation." (Xinhua)