SIPEX Update: 28 September – 10 October We have bid a fond farewell to the sea ice as we have reached the edge of the ice zone and are now in the open ocean heading for Hobart and home, so it is time for a short review of the last couple of weeks. When I last wrote, we were pretty much stationary in an area of heavily deformed ice, waiting for the ice pack to break up a bit and make travelling easier. Some of the biologists on board had noticed that the ice we were breaking through in that area was very brown on the underside. The brown colouring comes from the algae that live in and on the underside of the ice and are an important part of the sea ice ecosystem. There had been little algae in the sea ice we had sampled so far on this voyage and the biologist...

By Sandy Zicus, Antarctic Climate & Ecosystems Cooperative Research Centre We’re now a bit more than three weeks into our six-week Sea Ice Physics and Ecosystems eXperiment (SIPEX) adventure. On 18 September, we entered a section of land-fast ice surrounded by huge grounded icebergs, some of which have walls up to 50 metres high. It was impossible to capture the true scale with a camera (although most of us kept trying), especially when there was nothing of a known size in view to serve as a reference. Land-fast ice, often called just ‘fast ice’, is sea ice that is attached to land or to grounded icebergs. Fast ice is a bit different in character from regular sea ice. It is more or less permanent in one area and is generally not moved arou...

MEDIA RELEASE Media Release, 20 September 2007 Sea ice under scrutiny from space Lasers from helicopters and space satellites are being used in Antarctica, for the first time, to determine whether sea ice in the Southern Ocean is changing in response to climate change. Sea ice plays an essential role in regulating global climate as well as supporting the Southern Ocean ecosystem, and there are concerns that Antarctic sea ice may be getting thinner. A team of international researchers, led by the Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), is on a six-week expedition in the Southern Ocean aboard the Antarctic research ship Aurora Australis, which left Hobart earlier this month. ...

SIPEX: The first two weeks After 6 days and nights of rocking, rolling and bouncing our way through the Southern Ocean from Hobart, there was an abrupt change just before dawn and we were treated to a gentle rocking motion. Strong south-westerly winds during the previous day and night had pushed the sea ice to the north and caused more to form, so we reached the beginning of the ice a bit sooner than anticipated. First light revealed that we were going through bands of pancake ice - ice that forms as irregular roundish patties - separated by open water, some of which had an oily sheen to it. The sheen was caused by grease ice that forms when tiny ice crystals, known as frazil, are mixed through the top few meters of water. This is the first stage of sea ice de...