Science on ice

Prof Pat Langhorne (centre) and fellow researchers (from left) Dr Natalie Robinson and Dr David...
Prof Pat Langhorne (centre) and fellow researchers (from left) Dr Natalie Robinson and Dr David Dempsey on McMurdo Sound sea ice, in 2007. PHOTO: SUPPLIED

Pat Langhorne is a compelling case for the power and value of a curious mind. Bruce Munro talks to New Zealand's leading sea-ice scientist about a career that has taken her from private  polar puzzles to the heart of global climate change.

Paperwork, it appears, is the modern hallmark of success.

Professor Pat Langhorne (62) has been sitting at her computer in a roomy yet unremarkable corner office on the fifth floor of the maths and physics building on the northwest edge of the University of Otago's Dunedin campus.

She has been working on hoped-for budgets for the next two years' worth of sea-ice research in the Antarctic. Admin. That is what comes with the territory as you progress through the ranks.

Prof Pat Langhorne, of the  University of Otago physics department, has visited Antarctica 23...
Prof Pat Langhorne, of the University of Otago physics department, has visited Antarctica 23 times and hopes to return at the end of this year. PHOTO: PETER MCINTOSH

On the floor near the door, leaning against the wall, is a silver picture frame with a sky-blue board that frames two smiling black-and-white portrait photographs of Prof Langhorne and her husband Professor Vernon Squire.

It was a gift from physics colleagues when Prof Langhorne delivered her recent inaugural professorial lecture.

Still tied with ribbon in the university's colours, the photos will have to wait to be hung. There are students to teach and supervise, research to conduct and, yes, paperwork.

And now, with the professorial title comes a new element: public interest and questions.

Although that is not quite true. In reality, having to explain herself is something Prof Langhorne has done for decades. There was a time when she even had to justify being a woman scientist.

But now, as the former "blue sky'' researcher who has become New Zealand's leading sea-ice scientist and at the cutting edge of the global climate-change puzzle, the questions focus on what she has done, how, and why.

Prof Langhorne has been to the Arctic twice and to the Antarctic many more times than that. "I've been 23 times, I think,'' she says with furrowed brow.

"I don't know. Something like that. The length of stay has varied from a few days to several weeks.''

Her road to polar regions, however, was a long one.

Pat Langhorne during her first visit to Antarctica, in 1985. PHOTO: VERNON SQUIRE
Pat Langhorne during her first visit to Antarctica, in 1985. PHOTO: VERNON SQUIRE

Born and raised north of Glasgow, Scotland, her interest in ice research began as a teenager.

One of her lecturers at the University of Aberdeen, who had been with the British Antarctic Survey (BAS), encouraged her to apply to join the United Kingdom polar research group.

"I think he knew what the answer was going to be, but wanted me to challenge it,'' Prof Langhorne says.

She got through the first round of BAS selection, but not the second.

"It was 1976. I was 21. I had a degree in physics and that was what they wanted.

"They didn't have a place on the form that said gender. My name is Pat, so they didn't reject my application outright. And then, I suspect, one of my referees said 'she'.''

Instead, "she'' went to Cambridge University and did her PhD, which involved research in Canada's Arctic region.

"So, I did different things that let me get to polar places. And I did get to be part of a group asking these senior British Antarctic Survey gentlemen why women couldn't go. They said there wasn't the facilities.

"We were a bit mystified. We didn't quite know what facilities were needed: it was probably a bit of warmth, some food and drink and that was more or less it.''

Having married, and so looking for a reason to stay at Cambridge, Prof Langhorne applied for and got a postdoctoral fellowship in a subject she knew nothing about, jet engineering.

She was working for Prof Dame Ann Dowling, a top British mechanical engineer. Dame Ann was "fabulous'' and Prof Langhorne learnt a lot about organising and working in teams.

But her real interest remained on ice.

"I used to sneak off on Friday afternoons to the Scott Polar Library to see what had been happening in sea ice.''

So, in 1985, when Prof Langhorne's PhD mentor, Dr Bill Robinson, of New Zealand, offered her and Prof Squire the chance to go to the Antarctic on a Kiwi research expedition, they grabbed it.

Prof Langhorne then went back to being a jet engineer in the UK. But they had been impressed by what they saw in the South.

Three years later, they emigrated to New Zealand.

Prof Squire had a lectureship in the University of Otago maths department. Prof Langhorne, five months pregnant with the first of their two boys, eventually got a temporary assistant lectureship in physics.

A career highlight for Prof Langhorne was giving radio  instructions directly to the pilot of a...
A career highlight for Prof Langhorne was giving radio instructions directly to the pilot of a low-flying C130 Hercules military aircraft that was being used to help measure how waves affect sea ice. PHOTO: VERNON SQUIRE

Today, Prof Langhorne leads the sea-ice research component of the Deep South National Science Challenge; a multimillion dollar government-funded effort to bolster knowledge of global climate processes and prepare New Zealand for climate change.

Prof Langhorne's $1.9 million five year Antarctic sea-ice project will add vital pieces to the as-yet incomplete Earth System Model, helping scientists worldwide understand how elements of the global ecosystem interact and what the likely impacts of change will be.

But for her, it all began 32 years ago during that first trip to the Antarctic, with a curiosity about the strange behaviour of the sea ice.

"It started as a bit of mystery. We were in the area near Scott Base, and the sea ice there looked different from other places I had been to.''

In polar waters, there are two different types of ice, Prof Langhorne explains.

There is the ice shelf; ice that forms on land but is dragged by gravity until it forms huge tongues of ice floating on the water.

"We are not talking about little bits of ice floating about. These are enormous regions of ice that can be the size of France.''

And there is sea ice, which forms as seawater freezes.

In the Antarctic, where the ice shelf and the sea ice met, something unusual was going on.

"The thing that really gripped my attention ... was the fact that all this water sitting just under the sea ice was below its freezing point. It should have been frozen, but it wasn't.''

Instead, the "supercold'' water had ice crystals floating in it.

Platelet ice that has formed on a rope at depth is drawn to the surface. PHOTO: ANDY MAHONEY
Platelet ice that has formed on a rope at depth is drawn to the surface. PHOTO: ANDY MAHONEY

Others had already observed something of this phenomenon.

"There were people who worked on sea ice who said, 'We see this strange kind of ice and we know it is next to ice shelves'. And the ice shelf and oceanographer people said, 'Oh, we know that there's some process that goes on that melts ice at depth and refreezes it higher up'.''

But no-one had tried to "join the dots'' and figure out what was going on.

From the start, the research was purely driven by the quest for knowledge.

What Prof Langhorne and her students discovered was that it was a case of "nature always tries to even stuff out''.

"Nature sees that the ice from the land is very, very thick. It can be a hundred to a thousand metres thick. Whereas sea-ice around Antarctica can be one to two metres thick. It's nothing.

"So, essentially, a process takes place that tries to even out these thicknesses. You end up with very cold water coming out from beneath the ice shelf ... It has little ice crystals floating about in it.

"The physics of all that is going on I can tell you, but I doubt you want to know, right? The net result is that the sea ice gets thicker than it would be if it wasn't next to an ice shelf and the ice shelf gets a bit thinner.''

At that stage, Prof Langhorne and her students had no idea they were actually researching something that could also help build a better model for predicting global climate change.

Existing global climate models have a number of weaknesses. One of the major missing puzzle pieces is "Why is the Antarctic ice shelf not melting as quickly as expected?''.

Prof Langhorne's understanding of the interaction between sea ice and the ice shelf is thought to be part of the answer.

It is remarkable how much the spotlight has shifted on to what she and her team are doing.

"If I'm honest, our interest in this platelet ice was ... entirely blue skies research. You know, it was nothing to do with anything that mattered to anybody, except us.

"So we have gone from something that is totally blue skies to something that people at Harvard and MIT, Cambridge and Oxford and all the big universities are suddenly saying 'Oh, we need to know about this. This is important for understanding what the climate is doing'.

"It's the same thing for Vernon. He's been working on waves and sea ice all his life, and it has been a specialist area.

"But about 10 years ago - because the sea ice in the Arctic is melting, it means there are more waves there and that is breaking up the sea-ice more - more people became interested and got involved.''

Pat Langhorne (left) with fellow scientist and supervisor the late Jamie Rossiter, during sea-ice...
Pat Langhorne (left) with fellow scientist and supervisor the late Jamie Rossiter, during sea-ice research in Canada's Arctic region, in 1977. PHOTO: SUPPLIED

Going "down to the ice'' has never lost its thrill, Prof Langhorne says.

"It's absolutely an outstanding landscape; awe inspiring, of course. It is something else in August, when it is dark and there are auroras and seeing the amazing nacreous clouds. Absolutely stunning.

"The excitement for the winter-over team when the first sunrise for many months takes place is also very special.''

But with growing responsibilities the "feel'' has changed.

"The Antarctica New Zealand staff down there are fabulous mostly and it is very much focused on science, which is nice for us scientists.

"My view of it has changed a bit ... It's quite different if you are the project leader and you are concerned about whether it is going to work. There's more to lose and it might mean that you have to have more conversations about 'Well how is this going to work? How are we going to put things together so we get to do what we need to get done?'.''

And the work is done differently now too.

During the 1990s, a lot of their research was done away from Scott Base, living in specially kitted-out shipping containers.

"Before the platelet ice project there was the waves and ice project, doing mechanical measuring. It was more like engineering.

"And that engineering work was much better done at night when it was calmer.

"The wind is the thing that really makes life miserable. Not the cold so much.

"So, we would get up about 11am, start work about midday and then work to 3am, dinner at 5am and then to bed.''

"Nowadays, we tend to be more in keeping with the sort of day that Antarctica New Zealand like to keep. Their people are there for several months, and they would get very exhausted if they did that kind of thing.''

At the university, Prof Langhorne has climbed every step of the professional ladder from her start as a temporary assistant lecturer through to a senior lecturer and on to finally making professor.

As a woman in academia, her colleagues have been "really good to me''. But some "interesting things'' did happen early on.

"There was a strange case where I applied for some funding, but they couldn't interview me because I was temporary, so they interviewed my husband.

"These days, people would go, 'What? That's absurd'. But at the time, they were probably doing me a favour because the alternative was that they just said no, and in the end I did get some money.''

There is much greater awareness of issues for women now, but the statistics say there are still barriers, she says.

"For a long time, other women on permanent staff in physics were entirely in teaching roles, whereas I was the only one who was partly teaching and partly research. Happily, this has just changed this month with two more women on the faculty in physics.''

University of Otago doctoral student Alex Gough and Pat Langhorne prepare to spend winter on the...
University of Otago doctoral student Alex Gough and Pat Langhorne prepare to spend winter on the ice in the Antarctic in 2009. They are holdling a drill used for ice cores. PHOTO: ODT FILES

Teaching is still a pleasure. "It's a real privilege for an old codger like me to be around these smart young things. They're great.''

Motivation comes from a job well done.

"I'm driven by the respect of my colleagues more than anything else, probably. So, it probably worries me more than anything else, if they think what I did wasn't good.

"Doing good science also motivates me, which is the same thing really.

"So, I think you'll find with scientists, they are more interested in getting money for their research than money in their pocket.''

There is definitely more Antarctic sea-ice research to do, Prof Langhorne says.

"Yes, of course. Now we've got a picture of what happens close to the ice shelf, the question has become: how far does that influence extend away from the ice shelf?

"What we'd like to do is, near an ice shelf, fly around with the only gadget that does measure sea ice accurately from the air. It is called an EM-Bird, which uses a technique called electro-magnetic induction.

"We are hoping for more days of flying this year. But we are still waiting to see if we are on Antarctica New Zealand's schedule.''

It has not arrived yet, but the day to step aside will come, she says.

"I do have a sense that there comes a time to hand over. And better to stop when the going is good.''

But right now, there is some more paperwork to do.


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