A team of New Zealand scientists has just returned from studying the sea ice factories in Antarctica, in a joint expedition with Italy

A scientific Antarctic expedition is an expensive undertaking, but one we can't afford to skip if we want to know what's happening with the world's oceans

If you want to study the health of the world's oceans, you need to get to their heartbeat.

That's deep in the Ross Sea, where the sea ice factories of Antarctica - or polynyas - live.

Because of their remote location and harsh weather conditions they're tricky to measure, and they're under-represented in our climate models.

But a crew of Kiwi scientists have just returned from observing them, sending their state-of-the-art ocean gliders out to collect information.

They hitched a ride on the Italian icebreaker Laura Bassi, which was ironically able to get closer than usual because of melting sea ice.

The journey was a reaction to the collapse of sea ice last year, and had to be organised in a hurry.

"Science can move slowly most of the time," says Craig Stevens, the voyage leader on board the boat.

"It takes you a few years to decide on a problem, to write a proposal, a few years to do the work and a few years to publish it.

"We just don't have that time any more in terms of identifying the changes, and communicating the seriousness of that to all audiences, stretching from school kids to policy designers and everyone in between."

Today on The Detail we talk to Stevens, NIWA's principal scientist, and to Liv Cornellisen, two of the 12 New Zealand scientists who were on board the Laura Bassi.

Liv Cornellisen is a PhD student based at NIWA in Wellington, and affiliated with the University of Auckland. This was her first expedition, and the chance to observe in real life what she's been looking at from satellite data on her computer screen.

You can see polynya events from space, but while in Terra Nova Bay, Liv saw one for herself.

"It was super rough, we had high swells, high winds; it was freezing cold; I was very sea sick that day... but to actually be in there and experience just how big it is, and how much force nature has during these events... that was something that you wouldn't learn from just sitting at your laptop," she says.

A polynya event is when the ocean is opened by very high sea winds. Those high velocity winds drop with gravity down an ice shelf, pushing the sea ice away, exposing the ocean to more wind and freezing temperatures and creating new sea ice. Ross Sea polynas are the largest in Antarctica. …

Go to this episode on rnz.co.nz for more details