Quick Dips

Radar Study Of Ocean Waves

The Antarctic sea ice, exposed to the dynamic behaviour of the southern ocean, is the focus of a study by two Lower Hutt scientists at Scott Base.

Waves from severe storms flow towards Antarctica and crash onto the ice edge, contributing to the ice's eventual breakup. They are reflected by the ice and transfer energy to it in varying degrees.

Dr Murray Poulter and John McGregor, of DSIR Physical Sciences, are using a sophisticated microwave radar to measure the speed of the water, and to learn how waves react with the sea ice. The equipment reads the height, energy, frequency and direction of waves.

"Because of that, we can distinguish waves coming in to the ice and waves reflecting from it," said Poulter. "The difference of energy from one to the other must have gone into the ice."

The pair are using a strain-gauge placed further from the sea edge to find out if waves continue through the ice, deforming it. The three-year research project is into its second year, and is looking at a number of theories on the influence of waves on sea ice breakup.

"We're trying to understand the basic processes. Part of the overall project is looking at sea ice and how it behaves," Poulter says. "We need to know what breaks up the sea ice each year in the shapes and ways that it does break out."

Yvonne Martin, DSIR, Scott Base