20131219_IS
Source: BBC Radio 4
URL: http://www.bbc.co.uk/programmes/b03ls15v
Date: 19/12/2013
Event: Chris Turney: "Ultimately, global warming covers a vast array of different responses by our planet"
Attribution: BBC Radio 4, Inside Science
People:
- Dr. Adam Rutherford: Geneticist, author and broadcaster
- Professor Chris Turney: Professor of Climate Change, UNSW
Adam Rutherford: Now, a few weeks ago, I talked to Professor Chris Turney, just before he set off on an expedition to the Antarctic. His mission is to retrace the steps of the largely forgotten Edwardian explorer Douglas Mawson. Yesterday I spoke to Chris on a satellite link from the deck of the research ship Akademik Shokalskiy, currently moored in the shadow of a leviathan iceberg off the coast of Antarctica. I asked him how his scientific observations were going.
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Chris Turney: Oh, it's been going very, very well - we've been the last two days working on the actual sea ice itself, the guys have been taking temperature and salinity measurements from the ocean. The last two days some of the team have been doing reconnaissance, trying to get across to Mawson's hut, but that's proving very difficult, so we've just relocated 10K to the west, and we're going to try, a small group of us, tomorrow - half a dozen - to see if we can find a new route in to Mawson's hut, basically hugging the coastline, so we can get on with science there.
Adam Rutherford: What has been the problem, in terms of getting onto the ice itself - you're surrounded by thick sea ice - is that unusual for this time of year?
Chris Turney: Well, it's certainly a lot further out than it has been, certainly during the time of Mawson. We're at least one to two degrees further north of sea ice, compared to Mawson's time, which is extraordinary. No, the bigger issue, really, is this enormous iceberg, which, to be perfectly honest, "berg" doesn't do it justice, I think it's the size of Luxembourg, or something, so it's this enormous beast, and that's completely screwed up the local Commonwealth Bay, and it's just knocked up about three plus metres' worth of sea ice. In places, pressure points, and the like, have pinched in and it's very difficult to get our vehicles across the surface.
Adam Rutherford: And the presence of this ginormous iceberg and the thick sea ice - do you have an understanding of why it's like that, why that's different from other years?
Chris Turney: It was a bit of an Antarctic version of billiards, to be perfectly honest, an enormous berg broke out from the Ross Sea, and basically hugged the coast of Antarctica, and knocked the edge of this enormous glacier called the Mertz Glacier, which extended out beyond the coastline, around 120 kilometres. And that got knocked off and it's disappeared round - further round the Antarctic coastline, and instead this berg, this B9B, has locked down. But it's a fascinating analogue for this broader issue of, really, expanding sea ice across a large part of the East Antarctic.
Adam Rutherford: The fact that it's expanding, that - that sounds counter-intuitive, when we talk about the polar ice caps melting, as a result of global warming.
Chris Turney: Yeah, well, it's a fascinating thing, isn't it, really. Ultimately, global warming covers a vast array of different responses by our planet. And one of the fascinating things that we're seeing is suggestions that large parts of the oceans off East Antarctica are actually getting fresher. And yet you've got this expanding sea ice, and one of the ideas we're testing out here is this idea that when you're melting the sea ice around the East Antarctic coastal fringes, at depth - not from air temperature but from warmer oceans - what you're doing is you're putting that fresh water from the Antarctic ice sheets into the oceans. It's lighter, it's less dense than salt water, so it floats to the surface relatively, and then it's more vulnerable to freezing. And hence you get an expansion of sea ice cover. So that's one idea that we're testing at the moment.
Adam Rutherford: Give me an idea of what wildlife you can see.
Chris Turney: We have seen an amazing diversity of life here, we really have. Adelie penguins, I think are one of the favourites - they're relatively small and short, about 30, 40 centimetres in height and black on the head and white for the rest of the body. But saw an Emperor penguin this morning, which was stunning, absolutely stunning, we've seen Weddell seals, crabeater seals, we're been posting many of those images on the Intrepid Science Google Plus page for the expedition, but we also - we were doing a hangout on air, where we were broadcasting to the world, and during the film we actually had an orca coming right to the edge of the sea ice, which was absolutely astounding, blowing, blowing air and hissing and looking quite hungrily at us, actually, while we were filming. So, quite an incredible experience.
Adam Rutherford: Astonishing, and it sounds like I can hear some sort of bird in the background - are you being circled by some sort of bird?
Chris Turney: They're actually Adelie penguins - it's like Adelie penguin heaven here, they're everywhere, [laughing] just huge amounts of them, they're onshore, they leap out onto the surface, they're swimming past us, incredibly graceful creatures, and they're far noisier than you'd think.
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Adam Rutherford: Chris Turney - and on Wednesday night, GMT, after our chat, Chris announced on Twitter that they had indeed reached Mawson's hut. What he didn't mention was that during the interview, his team were all on the top deck of the ship, drinking gin and tonics - proper Edwardian exploration, what-what? That's it for Inside Science for today and from me for 2013. Professor Alice Roberts will be administering your science fix for the next fortnight. Happy Christmas - see you next year.