Ice Station Antarctica Horizon

This is Antarctica,

the last great wilderness.

It's the coldest, windiest, driest and most isolated place on Earth,

and it's home to the British Antarctic Survey's

Halley Research Station.

Here, cutting-edge science is making vital discoveries

about how our lives are vulnerable to the sun's activities

and threatened by man-made climate change.

It's 27th of January, 2016, and we're at 75 degrees south.

For the last couple of weeks, we've been on this ship behind me,

the RRS Ernest Shackleton, crossing the Southern Ocean.

We're making this journey to resupply the research station,

but this is also something of a rescue mission.

Although it appears to be on solid ground, Halley actually

sits on a constantly-moving and cracking ice shelf -

an ice shelf that's developed a chasm that threatens to

cast the station adrift on a massive iceberg -

and our cargo is part of the effort to stop that happening.

I'm Peter Gibbs,

and my job is working for the Met Office as a BBC weatherman

but back in my younger days

I worked as a meteorologist in Antarctica for over two years,

and I never, ever thought I'd get the opportunity to return.

'This is my journey to investigate the threat to Halley's future...'

-OK, Hilmar, here we go, then.

-Yeah.

It's going over the edge that's the worst bit.

'..and science at the end of the world.'

It is just phenomenal.

ICE CRACKS

My journey starts at the southern tip of Africa.

Here, the Royal Research Ship Ernest Shackleton is waiting for me.

As I go below to find my cabin and stow my bags...

FOGHORN HONKS

..we're soon underway.

We're heading out of Cape Town harbour -

you can probably see Table Mountain in the background behind me -

on our way to the frozen continent of Antarctica.

Now, we're expecting it to take about two weeks.

It's around about 3,000 miles.

We'll be going at ten to 12 knots,

so at just about a brisk cycling pace.

We're also heading through some of the roughest seas in the world,

so I'm a little bit nervous about that,

but really, really excited to be heading for Antarctica.

Well, it's the fourth day at sea.

About 660 miles south, now, of Cape Town.

The air temperature at the moment is ten degrees.

I've got the extra layer on.

The sea temperature's not much higher than that -

around about 11 degrees -

and you might notice we've got a big swell heading up from the south,

the direction we're heading.

The Ernest Shackleton has been making this long journey

across the Southern Ocean to resupply Halley since 1999,

but British scientific research goes back much further

and has a surprising beginning.

The modern-day British Antarctic Survey

actually has its roots in a secret wartime mission from World War II,

which was based up here on the peninsula

at Port Lockroy and Deception Island.

The idea of the operation was to protect

the waters around Antarctica,

particularly towards the Drake Passage towards South America,

from Nazi submarines.

But, even though the men based there were far from the bullets and bombs

of World War II, it certainly wasn't an easy posting -

Spartan living conditions, thousands of miles from home

and tremendous isolation.

But, in the event, it turned into more of a scientific expedition.

The men set up a weather station, one of the first on Antarctica,

and it provided viable data that's still used today

to assess climate change.

After the war, territorial claims led to 12 nations signing

the Antarctic Treaty, and this untouched landscape became a home

purely for scientific exploration.

For the British Antarctic Survey,

this meant a research station on the Brunt Ice Shelf.

And that's our destination - Halley Research Station.

The original building's long gone.

Even the buildings I lived in have long since drifted off,

entombed in the ice of an iceberg.

We've still got a long way to go - the best part of a week.

In fact, we are not even on the edge of this map yet.

Various incarnations of the Halley Research Station have endured

some of the most hostile conditions found on Earth for over 60 years.

The weather here is extreme.

Temperatures drop to over minus 50 Celsius,

winds can reach almost 150km an hour,

reducing visibility to just a few metres...

..and, for over three months every winter, the sun never rises.

Antarctica is also about as remote a place as you can find on Earth...

..but it's this remoteness that allows experiments to be

performed at Halley that simply can't be done anywhere else.

Well, this is the real deal now -

a huge iceberg that probably broke off the continent decades ago.

The point is, though,

if we were here in this spot at the end of winter, there would be

several hundred miles of continuous sea ice between us and the coast.

That's why it's impossible to get into Halley

for a good nine months of the year.

Back to the UK, now, and that frosty start in the south.

It's not going to last too long, though.

The sunshine, once it comes up,

clearing the frost fairly quickly, I think.

Further north, though, a bit of a different story...

'I've been waving my arms in front of weather charts for,

'well, 20-odd years now,'

but straight from university

I actually applied to the British Antarctic Survey.

I was taken on to be sent down as the weatherman

to their Halley Research Station, down in Antarctica,

but it was for two years.

That was standard back in those days.

This is a bit of a roughie-toughie shot,

but behind there you can see there's a pretty young man who is

just still getting to grips with the enormity of what he's...

he's actually taken on.

Once a month, we'd have a 200-word telex message in and out,

erm, but, to be honest, after a few months,

I was struggling to find very much to put into those 200-word messages.

And, essentially, for eight to nine months of the year,

there is no way to get anybody in or out

but, you know, I absolutely loved it. I really took to it.

Even after two years, when the ship came to actually take me away,

I... I didn't want to go.

I really didn't want to go.

Erm...

I had such an attachment to the place that

I really didn't want to leave it,

so to have the chance to actually go back is...is a big thing.

35 years on and e-mail has replaced telex,

but Halley is still as isolated as ever.

It's so far from civilisation,

it may as well be on another planet...

..and everyone posted there still needs to be utterly self-reliant.

I'm Jess. I'm the winter station leader

and I am in charge of making sure the station runs smoothly

over the winter, when we're down to a team of just 13 of us.

We don't have help, so all our emergency planning is

based on people on the station sorting themselves out.

We have to be prepared for any circumstances,

so, in an event like a fire, we have all our emergency supplies

elsewhere on station - in containers, in other buildings.

With outside help possibly months away,

the station has supplies to survive for almost 300 days.

Food allowances are calculated based on military rations,

and we add the polar allowance to that, which adds for the more...

more calories because of the colder weather.

We have a lot of stores -

1,500kg of tinned tomatoes and nearly 900kg of beef.

We never want to run out of food.

It's often said that the chef is one of the most important

people on the station.

My name is Victoria Stone and I'm the winter chef.

I'll be here, then, until 2017.

It is that kind of a world, you don't have to worry about things.

I mean, I haven't been out here long but I absolutely love it.

I think food is really important, working at Halley, because it's...

You're working in severe conditions.

You're away from friends and family and, you know,

that's the one thing that you look forward to,

and everyone talks about it -

what we're having for lunch, what's for evening dinner and...

So it's a very big responsibility, but I'm quite happy with that, so...

ICE SNAPS AND BOAT RUMBLES

Even in summer,

sailing through the Southern Ocean to get to Halley is a challenge.

BOAT RUMBLES

Well, we finally hit the edge of the Weddell Sea pack ice last night,

and I mean hit.

There was an almighty bang as we struck the first floe,

and I was startled awake.

The sound when you're actually inside the ship is just remarkable.

It's almost like you're inside a war zone,

and this is what the ship's

designed to... BOAT THUDS

do, power through ice.

I'll tell you what,

it's still a bit nerve-racking until you actually get used to it.

As we crunch through the ice,

the captain offers me the chance of a lifetime -

something I'd secretly been hoping to do -

drive his 1,800-tonne ship.

Are you sure about this, John?

Yeah.

At the moment we've got 83% pitch, which is basically your power,

which is giving us about ten knots, but it will build up,

cos we're in a patch of open water here.

So, just be careful what you hit at that sort of speed.

-Yes, I will.

-But the...

It's a strange sort of feeling of power and terror, actually.

So, if you... You take that.

You've got some nice... nice new ice coming up, here,

and just aim for the crack

-and she'll follow it along.

-PETER CHUCKLES

-It's rather like a...

-That incredible -

the speed that crack's actually formed, right across the whole floe.

There's a good covering of snow

-on most of these floes, as well.

-Oh. BOAT THUDS

So that'll be...

It's probably the best part of a metre thick,

with the snow on the top.

-It's certainly slowed us down a bit.

-Yes.

-And are we OK to hit this bit of ice coming up?

-Yup.

You might want to just drop your pitch...

-Drop your power a bit there.

-Slow down a touch...

-Yeah.

..so we don't give people downstairs a shock.

I'm Jamie Shaw. I'm chief engineer on the Ernest Shackleton.

I've been here for nearly seven years.

We're a reinforced general cargo ship, built in Norway,

and the ice belt, which is the part that does the actual icebreaking,

if you like, is... the steel's about that thick,

so Norwegians build very good ships.

Generally speaking, the bridge, they try and find the cracks,

sort of, between the ice, but the bridge enjoy it.

We actually go straight for it and, literally, bash our way through it.

It's good fun for the first few hours

but, when you're doing it for days on end and you're trying to sleep,

it's not quite so much fun.

You can sometimes tell who's driving, as well,

so some of the younger ones are...

They're definitely there with the throttles, going for it,

and you think, "Oh, here we go." You know, bang, crash, you know?

But maybe us older people would maybe go round a little bit.

Now, we're coming up to a floe that's

a good few hundred metres across.

-Are we going to get through this?

-Erm, you...

What you... What you look for...

You're going to say I'm being a bit ambitious.

THEY LAUGH

My piloting skills have the local penguins fleeing in terror

but I'm not stopping for anything.

I have to say, this is fantastic fun.

I can see why you keep coming back down here, John.

It is. We spend our whole careers at sea, trying to avoid other things...

-Yeah.

-..and this is our one chance to hit everything in sight.

ICE CRACKS

BOAT CLANGS

Breaking through sea ice is an unforgettable experience,

like exploring another universe in a spaceship,

but we're still a world away from our destination.

Even through the Halley Research Station appears to be

built on solid ground, it isn't.

Its home is the Brunt Ice Shelf - a seemingly endless frozen sea -

and, for the research station, this is a problem.

The ice shelves that surround Antarctica are glaciers that

have flowed down from the continent's landmass.

Hundreds of metres thick, they crack as they spread

like a stiff honey across the sea's surface.

I'm Hilmar Gudmundsson. I am a glaciologist.

I think glaciers are really cool.

So, ice shelves grow with time,

as more and more ice is being added,

and typically they then lose mass

through an event that they call calving,

which is basically the breaking off of a chunk of the ice shelf,

which breaks away and then floats as a tabular iceberg.

This is a natural process, which you always expect.

It's certainly happened in the past.

It happens with other ice shelves as well

and certainly will happen again and again in the future.

On Brunt Ice Shelf, we have a particular situation right now,

which is that there's a crack that has formed.

It was formed at least 30 years ago,

but recently it has started to grow again.

Now, if this crack were to continue to grow at the same rate

as it has over the last few years, in the same direction,

then eventually it will cut across the whole ice shelf.

We know there was a huge calving event between 1915 and 1956,

when the coastline of the ice shelf dramatically changed,

and now the ice shelf has almost extended to its 1915 profile,

so another major calving event is due.

If that happens, then the research station itself will be

cast adrift into the Southern Ocean on a huge tabular iceberg.

Well, here it is.

That glistening white line in the distance

are the icy ramparts of the Caird Coast -

the continent of Antarctica.

A coast first spotted and named by Shackleton just over 100 years ago,

before he got trapped in the ice just further down the coast here,

and first spotted by me 36 years ago

and, I have to say, there's...

There's a bit of that young man certainly coming back

as I stand here at the moment.

It's pretty emotional.

It's... It feels like coming home.

My first sight of the ice shelf brings back a flood of memories.

It's a bleak, beautiful place -

an alien world, right here on planet Earth.

And it's a treacherous landscape -

at any moment, at the water's edge, a section could collapse.

But it's highest through here...

'But we have a job to do,

'delivering supplies for the research station'

and, with no docks, like everything else in Antarctica,

you make what you need yourself.

So, Captain Harper creates a berth

by running the ship alongside the ice.

If the shelf doesn't collapse, so the theory goes,

it's safe to go ashore.

Violent southern ocean storms could drive the Shackleton

off the ice shelf, so, as the weather closes in,

the rest of our day is spent securing the ship.

This means all hands, including me, go to work

digging four massive anchors deep into the ice.

ENGINE HUMS

The sun has come out to greet us

for the last leg of our journey.

The 30km snowcat ride across the blindingly white ice shelf

seems endless but, after two weeks at sea waiting for this moment,

I'm not disappointed.

Well, there it is.

I mean, I've seen pictures, but when you see it for real

it's just an incredible building.

I mean, it's like something out of The Martian

or 2001: A Space Odyssey.

Time to get inside.

'Built in 2012, the Halley Research Station consists of

'eight huge modules and, just like a moon-base,

'they have everything needed to maintain life

'in a hostile environment.'

All right, I'm going to take you through from one end,

right through to the other.

So, we're starting in the quiet room, which doubles up as a library,

and we move out of there

into the first part of the accommodation block.

-Now, we're into a sort of admin area.

-Hello.

We've got the communications room on the left.

We've got the equipment here, on the right, in case of fire,

and a board up here where you have to tag in and tag out -

safety, a very big concern here at the moment.

Surgery over on the right.

Now, we're moving through into the main dining room and lounge area.

So, this is the real, sort of, hub of the station

far off to the left here.

Oh, and along the wall on this corridor

that we're just coming past,

all the pictures of past winterers,

starting from 1956, right through to the present day.

'And, of course, there's me and the rest of the guys in 1981,

'and you'll notice, back then, no women.'

OK, let's move on. We're going through.

Now, you'll start to hear a bit of a hum.

We're moving through the sort of plant area.

So, things like the... the generators.

And now, a big, deep breath.

We're going outside, through these heavy, airlock-type doors.

STRONG WIND BLOWS

WIND CONTINUES

And now we're on into the main science area,

so, the labs either side,

and now we're going to go up the stairs to

the best view in Halley,

which is the Met Office observation deck,

where you get a panoramic view of the Brunt Ice Shelf.

This ice shelf is just a small part of Antarctica.

It's a vast continent, almost twice the size of Australia.

It contains 70% of the world's fresh water,

trapped in an ice sheet that's up to 5km thick

and, because of this,

Antarctica is a huge influence on global weather patterns,

so monitoring what goes on here is critical.

For 60 years, Halley has delivered a continuous stream of weather data

for scientists around the world to use in climate models,

so every single morning sees the launch of a weather balloon.

Amy, one of the disadvantages of this job,

is that you've got to get up before

most of the people on the station, isn't it?

It's only during summer, though.

In winter, we launch at 10.30.

That's a bit more civilised.

'Civilised perhaps, but when I did this job in the early 1980s,

'this was a tricky operation.'

-So, Amy, this is just a one-person job now, yes?

-Yes, it is.

Cos when I was here

it needed four people to actually do a balloon ascent every day.

Wow.

Cos you had... You had to track it by radar,

so there were two people sitting in the radar,

tracking the balloon and sending the measurements back to

the Met Office, where there was two people sitting,

plotting it out on a map,

working out the winds from that using a calculator,

coding it all up and then sending it off by telex.

'40 research stations, dotted across this vast wilderness,

'provide all the data for the whole of Antarctica's weather patterns.'

Because there are so few measurement stations in Antarctica,

every single measurement from every station counts, and we get

-a call from the Met Office if we start to miss more than one.

-Really?

-Yes.

-Oh, well, that's good because, of course,

you have to have that spread of data,

otherwise the models don't work as well.

'Each weather balloon is filled with helium to lift it high into the

'atmosphere, and it carries a little white box called a radiosonde.'

So, this measures pressure, temperature and relative humidity,

and it's also got a GPS in it.

And the key thing is that it's giving us a profile

through the atmosphere.

And you're getting these things up to what sort of height?

So, we're interested at the height of about 10km,

but they continue on up to about 25-30km.

But they get to a huge size, don't they, before they actually burst?

Yeah, about the size of a double-decker bus.

It's hard to believe when you see this thing here.

OK, well, I suppose it's getting towards time to release.

Would you like to launch it?

I'd love to. Thank you.

Yeah, that'd be... That'd be a real privilege, thank you.

-OK.

-When you're ready.

Three, two, one, and go.

Well, that launch was pretty straightforward this morning

but then it's the middle of summer here,

the temperature a fairly balmy minus 8.

Imagine doing that in the middle of winter.

Three and a half months of darkness here at Halley,

temperatures down as low as minus 56 Celsius,

and often severe wind-chill, as well.

And it's that severe winter weather that creates a mass of

heavy, dense, cold air across the Antarctic continent, that actually

isolates the atmosphere from the circulation around it.

You get these winds whipping around the cold air.

It's what we meteorologists call the Antarctic polar vortex,

and that weather feature was instrumental in creating

a deadly threat to every living thing on the planet.

Back in the early '80s, when I was last here,

Halley was at the centre of a global environmental news story,

all about a frightening man-made hole high in the stratosphere.

An aerosol can -

the argument goes that sprays are destroying

a vital part of the Earth's atmosphere.

There's a two-mile-thick layer of a gas called ozone just here,

about ten miles above the Earth.

Ozone matters because it does one crucial thing -

it shields all life on the Earth's surface

from the sun's harmful radiation.

Scientists at Halley discovered that each spring,

as the sun reappeared, ozone levels above here dropped dramatically.

They were so surprised that they went back and checked

and rechecked their results.

In fact, what they'd found was a hole in the ozone layer

the size of Antarctica,

and this is the machine that discovered the ozone hole.

This is the Dobson spectrophotometer.

This actual instrument was here -

it was the one we used when I was here back in the 1980s -

but it was invented back in the 1920s

by Oxford scientist GMB Dobson,

basically in his garden shed,

but, even now, almost 100 years later,

it's still the gold standard for ozone measurement.

MACHINE HUMS

Essentially what it's telling us is how much harmful UV radiation

gets down to the Earth's surface.

What the spectrophotometer detected in the '80s was

the effect of man-made gases, used in spray cans and fridges,

trapped within Antarctica's polar vortex.

In winter, the cold air circulating high above the continent

forms stratospheric ice clouds, containing these gases

and, when the spring sun returns, they act as a catalyst,

destroying ozone.

Ozone has been measured daily here at Halley since the mid-1950s,

but it was the change in levels during the '70s and '80s that led

scientists to realise that it was being destroyed in the stratosphere.

That then led onto the signing of the Montreal Protocol in 1987

to ban ozone-destroying chemicals like CFCs.

It was an unprecedented feat of

international cooperation. MACHINE HUMS

Measurements are still being taken on a daily basis

and what they show is that it will take at least to

the end of the century for levels to return to near normal,

so it seems as if the rot has stopped.

Studying the atmosphere at Halley is critical.

Antarctica is a huge, ice-covered continent, surrounded by ocean,

and when that ocean freezes during the winter,

for as much as 1,000 miles, it doubles the area of ice.

That yearly heartbeat is a huge influence on the planet's climate,

and also, the Southern Oceans are a big player in absorbing carbon

from the atmosphere.

The endless storms that circulate around the periphery

of Antarctica drive a global conveyor belt of oceanic heat.

While this place may be out of sight for most of us,

what happens here in Antarctica affects us all.

But, today, the very existence of this unique research facility

is threatened.

A huge crack across the Brunt Ice Shelf is expanding,

and it may cause the research station to float off

into the Southern Ocean.

For glaciologist Hilmar Gudmundsson,

it's like watching geology in fast forward,

so this faultline is constantly monitored,

and there really is only one way to get a closer look.

The last time I abseiled was 35 years ago, so I'm a little nervous.

-OK, Hilmar. Here we go, then.

-Yeah.

It's going over the edge that's the worst bit for me.

It's quite a long way down, isn't it?

I've been looking at this crack from satellite images,

and now being within it is just great.

This is a feature which has been here for ages.

Just phenomenal.

'When low cloud and snow reflect and diffuse the sunlight,

'the full extent of the chasm is difficult to see,

'but when the sun comes out, it's a different story.'

This is, as you can see, a fairly large crack.

It's a chasm, that's what they call it. Chasm 1, in fact.

Yeah, chasm, chasm sounds about right from where I'm sitting.

-Across, I would say this is maybe 80...80m at least...

-Yeah.

..and the whole thing is getting wider as we speak,

by about 15cm every day.

-Every day?

-Every day.

15cm from this edge here to the other one over there,

and it's been going like a clock

ever since we started to measure this, which is...

which was early 2015.

And, Hilmar, the bottom of the chasm, there,

looks very different to the ice round about.

This is very blue, very white...

-It's much darker down in the bottom, there.

-Yeah.

Yeah, I suspect down there we're literally at sea level.

It is the colour of the ocean which is causing this slight tint.

'Hilmar is keen to investigate

'whether we are actually at sea level,

'and that means going right to the very bottom of the chasm.'

Ooh!

That's better.

'It's a huge relief getting down,

'but we don't take off our safety lines.

'With the freezing Southern Ocean just beneath our feet,

'we're treading very carefully.'

..poke in there, so let's have a look.

Matt, are you happy with us going down here?

-If you follow the trail we've made previously, that'd be good.

-OK.

-Are you OK?

-Yeah, it's fine. LAUGHTER

-OK, he's safe.

-I nearly got my foot wet.

-Fantastic.

-OK, I'll follow - maybe not quite as elegantly as you did.

A slightly different way, yeah.

And that is going...

-It's salty.

-It's salty?

-It's salty!

-It really is? Oh.

I wasn't expecting this.

Is that a first for you?

Yeah, yeah, I thought we had, maybe, one or two metres here

of solid ice on top.

So we're on this huge, floating mass of ice,

which is 150m thick.

We've had a journey up from the coast of three hours in the snowcat.

We've come an hour and a half in from the base,

across this featureless snow plain,

to this massive, great chasm,

and you get down to the bottom of it,

and you actually find seawater in there. It's really...

It feels like you're in the belly of the ice shelf,

and it just brings it home how sort of precarious

this whole landscape actually is.

I guess, because it's always breaking up, it's growing,

it's widening by about 15cm a day,

the sea ice formation just can't keep up with it.

This rapid expansion of the chasm may prevent sea ice from forming,

but it's not the width that's the threat to

the Halley Research Station - it's the length.

At the same time that this gets wider,

it also gets longer by about 1.7km a year.

So, if it kept on going at that rate, in that direction,

eventually it's going to reach the sea at the other side of

-the ice shelf, and you've got a massive iceberg.

-Yes.

And, of course, the problem here is,

Halley, the station, is on that developing iceberg.

Yes.

ENGINE HUMS

Keeping Halley operational on this particular ice shelf is critical,

not just for monitoring the weather.

60 years ago, it was sited here, along with numerous aerials,

to investigate the interactions between the Earth and the sun.

My name's Richard Horne.

I work at the British Antarctic Survey

and I lead the Space, Weather and Atmosphere team.

Halley is our window into space - that's what we call it -

and I just feel like the luckiest person on Earth, really.

Each winter at Halley, there's a dazzling display of light -

the aurora australis.

"Curtains waving" is one of the best descriptions,

actually given by the early Norsemen, many, many years ago.

But, when I see the aurora,

I also think of huge electrical currents

which are coming down from space, crashing through the atmosphere.

The electrons are being accelerated across the Earth's magnetic field

and then exciting the molecules in the atmosphere,

and then they give off the light that we see.

That's really what the aurora is about.

The aurora are only possible at the North and South Poles

because of the shape of the Earth's magnetic field

and, by monitoring what goes on above our heads,

Halley's location gives scientists the opportunity to

protect our modern world from the sun's destructive activity.

This is the Maggy Tunnel.

It's called that because it houses the magnetometer,

which needs a constant temperature

and, buried ten metres down here in the ice shelf,

the temperature never really varies from minus 15 year round.

This thing is measuring fluctuations in the Earth's magnetic field.

The flow of the planet's molten iron core is what creates

the Earth's magnetic field.

Field lines stretch out into space -

60,000km facing the sun

and trailing away some 400,000km on the dark side of the Earth.

These field lines can't be seen, but we do witness the aurora

when they are disrupted by the sun's coronal mass ejections.

A coronal mass ejection emits billions of tonnes of

charged particles and when they come towards the Earth

they see the Earth's magnetic field as a barrier,

but it has the potential of ripping open the outer layers

of the Earth's magnetic field, drawing the field

across the polar caps and extending the magnetic field into the tail.

The magnetic field lines on the dark side of the Earth, suddenly,

violently, they snap back into place.

The analogy is an earthquake in space, if you like,

and that whole process really is the start of a large, geomagnetic storm,

and the manifestation of that is the aurora that you

see in the polar regions.

But Halley isn't just under the auroral zone...

..it also sits within a unique glitch in the Earth's magnetic field,

called the South Atlantic anomaly,

and for scientists it's a window into space that allows them

to study the radio waves thrown out by those coronal mass ejections.

Our research has shown that those radio waves

can accelerate charged particles up to very, very high energies

and damage the spacecraft.

We call them killer electrons.

Killer electrons become trapped in magnetic fields

wrapped around the Earth called the Van Allen radiation belts.

And during a magnetic storm caused by a coronal mass ejection

they can increase 10,000-fold in as little as two minutes.

The problem is that over half of all satellites

pass through the Van Allen belts as they orbit the Earth.

The charged particles can penetrate the outer skin of a spacecraft

and then they get buried into circuit boards, insulators,

cables, and that charge can then build up.

If it builds up to a very high level,

it can cause electrostatic discharge.

The analogy, really, is a lightning bolt.

And they have been related to the loss of a spacecraft,

the total satellite loss, costing 250 million.

That's a lot of money.

And you think that there are something like

1,200 satellites on orbit in total.

The space weather research done here

is attempting to forecast the impact of geomagnetic storms

because of the damage they can do.

We need to know what

the largest level of the radiation can be in a severe storm

because we can then give that information to the designers

and they can then design against that to help protect the spacecraft.

Whilst the impact of the sun on the Earth

is measured by the aerials and radar installations OUTSIDE Halley,

inside, other experiments are looking other much further field.

In the depths of winter it's permanently dark,

with temperatures that are hostile to any living creature

and with little physical contact with the outside world,

it's the nearest thing we have here on Earth to surviving in space.

For the station's medic,

these extreme conditions are a gift to do some interplanetary research

because she is allowed to use its winter inhabitants

as guinea-pig astronauts.

I hear the winterers have a name for you, is that right?

That is right, Peter, I see you are well informed.

Well, since they call me Madame Whiplash,

why don't you take a seat and find out why?

LAUGHING: OK, let's try it!

'I'm quite relieved to find Nathalie's leather chair

'is simply the seat for her Soyuz docking simulator!'

-RADIO:

-'We are at the range of 55 metres,

'everything is nominal,

'crosshairs are aligned with the target.'

In December 2015, en route to the International Space Station,

Tim Peake and his crew encountered a problem.

In his launch the automatic system failed

and so the Russian pilot had to dock it manually

and it's exactly the procedure that we're going to do here.

-So, were the staff here saying, "I could have done that!"

-Yes!

They were all saying it!

-Fantastic!

-Piece of cake.

Of course, Tim's mission docked successfully.

It's going to be interesting to see how I get on.

You want to move in as fast as possible

because time is one of the critical items,

but your closing velocity can never exceed your distance divided by 200.

And the computer does that, right?

No, you have to do that.

THEY LAUGH

So I've got to do mental arithmetic

and control two joysticks at the same time?

Well, YOU wanted to be an astronaut!

Do you know, I did once, but I'm not quite so sure now!

-So, you are 35 metres away now.

-OK.

So, let's further correct that negative drift that has reappeared.

Oh, yes. I'm getting nervous now!

I can feel my heart going!

So, what are you actually testing with this system?

Well, as you will see

when you will be perfectly proficient in this task,

is that once you reach a standardised level of performance,

if you don't practise it for a while, you forget it.

And this is a major problem for exploration space flight

because it...

if we train a pilot and we send him or her to Mars,

this really long journey, we expect them to be on top of their game

when they arrive and so the question here is,

what is the frequency of training you need

to actually keep a certain level of proficiency up?

So, we have a group of winterers who train frequently

and a group of winterers who train infrequently

and it is to quantify the rate of skill degradation in both groups.

And it's the isolation, it's the winter darkness,

sort of simulating what you would experience

during a long-duration space flight?

Well, it's not simulating, it IS long and dark.

Yes, that's true.

And there is no escape.

And for ethical reasons, this is something we can't simulate.

Even if in the middle of winter you say,

"No, no, no, no, I've changed my mind, I really want out now,"

-you can't.

-You have to just deal with it?

Yeah, indeed.

Getting very close now, five metres.

I'm now trying to...

..look at two screens at once

with crosses going in different directions.

And brake, brake, brake because you are going to overshoot.

Yep.

Two metres.

SIMULATOR WHIRS

'Pictures show capture and hard dock.'

PETER LAUGHS We're in! Fantastic!

-Well done!

-I'm exhausted!

Tim Peake is going to start getting very worried.

NATHALIE LAUGHS

Arguably, back here on Earth, Halley's most important work

is to look out for signs of climate change.

Neil, this snow surface actually

is almost perfect, isn't it, for skiing?

Yeah, it's absolutely great, it's lovely and soft.

And it's this snow, within Halley's clean-air sector,

that we've come to take a closer look at.

This is not the easiest, with big boots on, is it?

No, definitely not.

The prevailing wind arriving here

blows over 2,000 miles of an untouched continent,

making it the purest air in the world.

So, when it's trapped by the snow falling here,

isolating pollutants created by human activity is made a lot easier.

And operations at Halley mean that purity is guaranteed.

There's no vehicles that come down here.

People... The only way to get into this area

is to either walk or to ski.

Right, suit on, what's next?

First of all, we need a hole and that will take some time.

Right, well, that's going to warm us up.

We are wearing these fetching overalls

to prevent us contaminating the snow samples.

I'm suffering for science!

Because the air here is so pure,

chemicals trapped in the snow reveal historic climate change.

Well, snow sampling gives us

a present-day understanding of the atmosphere

as compared to ice cores,

which provide an atmospheric reference to the past.

If we can link these two together,

we can provide a better understanding

of what the atmosphere will be like in the future

and the effects that will have on our climate.

Millennium-old ice cores only contain natural pollutants

from forest fires and volcanic eruptions.

The snow samples contain everything man-made in the modern world.

So comparing the two can help determine

the impact those pollutant levels may have on the climate.

But that's not the whole story.

Another kilometre further away is the Clean Air Lab.

The monitoring equipment here is so sensitive

it can detect forest fires and volcanic eruptions

as far away as South America or Africa.

I'm breathing the cleanest air on the planet!

-I like that!

-Yeah.

The Clean Air Lab is searching for evidence of global warming,

in particular the greenhouse gases CO2 and methane.

So, here we've got the sample pipe.

The air comes in, a small off-take is taken

and goes into the instrument

and that's where we measure the air outside, the clean air outside.

And these are the real-time values that we're seeing

of what actually are all greenhouse gases.

Yes, as we know, CO2 is one of the main greenhouse gases at the moment.

As you can see, it's about 398 parts per million.

Now, I've been an atmospheric chemist

probably for the past 16 years.

When I first started, it was around 375,

so it's probably increased by nearly 10% or thereabouts...

-In that time?

-Yes.

How can we be sure that those levels that you're seeing increasing

are actually coming from human activity?

Well, the only other way you could get a large amount of CO2

into the atmosphere is probably through volcano eruptions

and we know there hasn't really been any large volcanic eruptions

in the last...150 years, so we can categorically say

that it's more than likely come from fossil burning.

Although volcanoes erupt all the time,

there have been no major events for over a century

and the present concentration of atmospheric CO2, carbon dioxide,

is higher than it has been for almost 1,000,000 years.

But for atmospheric chemists,

CO2 is also an indicator of what could happen

with a far more dangerous greenhouse gas - CH4 or methane.

And as you can see here, the level of methane

is less than two parts per million, so it's a lot less than CO2.

But we know that we are putting more CO2 into the atmosphere,

so we are heating up the atmosphere.

As the atmosphere starts to warm up,

the oceans will start to warm up and as the oceans start to warm up,

more CO2 will come off the oceans

and then you get sort of a runaway effect,

so if this keeps rising

then there's a chance that that permafrost is going to start to melt

and with that, we are going to get the release of methane.

The permafrost of the Northern Hemisphere

across Russia and North America

holds vast amounts of methane within its frozen soil

and this gas is an even bigger threat than CO2.

Methane, even though it's a lot smaller in concentration,

is 20 times more potent as a greenhouse gas than CO2,

so methane in the future could well be the one.

For Neil, the danger is clear.

He thinks that rising CO2 levels

could cause the release of more methane into the atmosphere

and that this gas is likely to have

a far greater impact on global warming.

But even today,

the current levels of these greenhouse gases are being felt.

Long-term measurements have found

that temperatures across the Antarctic Peninsula

have risen by over 3 degrees Celsius over the last 60 years.

That's more than ten times the global average.

Over the next century, greenhouse gases will drive further warming

across Antarctica and its surrounding seas.

The work being done at Halley is vital.

We need to understand those processes

to be able to predict the impact of that future warming.

But Halley has to cope in this hostile environment

and each year it's a challenge to survive.

Well, Mike, thanks for letting me into the cab.

-Is this your normal job?

-It's my first season in Antarctica.

I'm normally a farmer back at home, up in East Yorkshire.

It's a similar flat landscape,

but obviously a very different colour.

You're not going to grow much here either, are you?

No, I don't think it would be very easy to get a crop of spuds off...

-They wouldn't do too well around here, I reckon.

-No.

Although it may look flat and unchanging,

each winter huge snowdrifts accumulate

around the research station.

And each summer they need to be shifted.

What we're doing at the moment is we're pushing the wind tails,

which is the snow from the winter, away from the modules,

so we are having to move about 1.5 metres of snow away

and flattening the site out.

And this is really the machine for doing it, isn't it?

Yeah, this is about 450 horsepower

and it's great at moving huge quantities of snow.

The station I was in back in the early '80s

had been there for nearly ten years when I got here,

but it was designed to be buried,

so it was like living in a submarine under the ice

-in these huts, in metal tubes.

-Yeah.

You were about 50 feet down.

Halley III finally succumbed,

entombed and crushed by the mounting snow.

It was abandoned a year after I left in 1983,

but amazingly, finally reappeared years later

at the edge of the ice shelf.

Holding back nature in Antarctica is virtually impossible,

but this is something Halley's designers have thought about.

This station is designed to be jacked up every year,

so that's what we've been doing the past couple of weeks,

is involved in raising the station by two metres.

Sitting on massive hydraulic jacks

means Halley now keeps itself happily above the snow's surface.

However, there is still the threat of the chasm.

As it lengthens, the greater the chance that

the research station finds itself floating into the Southern Ocean.

But there's another unusual feature in Halley's design,

the first of its kind, which will help it survive.

At the bottom of its hydraulic legs are huge skis...

..so each module will be detached from its neighbour

then dragged to a new site

in the same way it was brought here four years ago.

After extensive surveys, a new location has been found 20km away,

safely on the other side of the chasm.

And there, Halley can continue its work.

Before we head home, at the edge of the ice shelf

all the ship's cargo is finally unloaded.

These big, red shipping containers we brought down on the Shackleton

contain living accommodation - kitchen, bedrooms,

bathrooms, working spaces - and they are going to be used

to build a temporary camp for the team up at Halley VI.

So it's all hands on deck at the moment,

the container is being craned out over the ice

onto these heavy-duty sledges

that will then be dragged all the way up to Halley VI.

Once the temporary accommodation is set up,

then Halley can be moved out of danger.

After an all-too-brief nine days on the ice shelf, I'm heading for home.

It's a bittersweet farewell

to somewhere I'm unlikely to ever see again.

I wasn't sure what it would be like,

coming back here after all these years.

What I found is a landscape that is completely unchanged,

but an operation that is on a different scale

to what I experienced back in the early '80s.

It feels much more professional.

The science is bigger, there's more experiments,

and yet this place has such a huge influence

on the planet's weather and climate,

which is why the work done here at Halley is so vital.

I thoroughly enjoyed my time back on the ice.

I was worried what it was going to be like leaving.

To be honest, I thought I'd probably just fall apart,

but actually, I don't know, it feels like I've come full circle, it's...

it's feeling like the end of a journey

that I started half a lifetime ago.