Ice Station Antarctica: Part Two 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 January 27, 2016, and we're at 75 degrees south. For the

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

Shackleton, crossing the Sothern 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, Hally sits on a

constantly moving and cracking ice shelf, which has a chasm that

threatens to cast the station adrift on a massive iceberg. Our cargo is

part of the effort to stop that happening. I'm Peter Gibbs, 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. I never, ever thought I'd get the opportunity to return. This

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

go then. It's going over the edge that's the worst bit. And science at

the end of the world. It's just phenomenal.

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. The

sunshine, once it comes up, clearing the frost fairly quickly.

I've been waving my arms in front of weather charts for 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 in Antarctica. It was for two years

that. Was standard in those days. This is a bit of a roughy, toughy

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

still getting to grips with the enormity of what he's actually taken

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

To be honest, after a few months, I was struggling find very much to put

into those 200-word messages. Essentially, for eight, nine months

of the year, there is no way to get anybody in or out. But I absolutely

lovered it. I really took to it. -- loved it. I really took to it. Even

after two years, when the ship came to take me away, I didn't want to

go. I really didn't want to go. 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 a big thing. 35 years on, and e-mail has replaced

telex, but Halley is still as isolated as ever. 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. 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 station sorting themselves out. We have to be prepared for any

circumstances, so in the event like a fire, we have 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. We add the polar allowance to that, which adds for the more

calories because of the colder weather. We have a lot of stores,

1500 kilograms of tinned tomatoes. Nearly 900 kilograms 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 station.

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 five

kilometres thick. And because of this, Antarctica is a huge influence

on global weather patterns. So monitoring what goes on here is

critical. 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 hull 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 re-appeared, ozone levels above

here dropped dramatically. They were so surprised they went back and

checked and rechecked their results. In fact what they found was a hole

in the ozone layer the size of Antarctica. This is the machine that

discovered the ozone hole, this is the Dobson spectramanometer. This

was here in the 1980s, but it was invented in the 1920s by GMB Dobson,

basically in his garden shed. Even now almost 100 years later, it's the

gold standard for ozone measurement. Essentially what it's telling us is

how much harmful UV radiation gets down to the earth's surface. What it

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. When the spring sun

returns, they act as a catalyst, destroying ozone. Ozone has been

measured daily here at Halley since the mid-1950s. It was the change in

levels in the 70s and 80s that led scientists to realise that it was

being destroyed in the stratosphere. That then led on to the signing of

the Montreal protocol in 1987 to ban ozone destroying chemicals like

CFCs. It was an unprecedented feat of international cooperation.

Measurements are still being taken on a daily basis, 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 a thousand miles, it doubles the area

of ice. That yearly heart beat is a huge influence on the planet's

climate. Also the Sothern Oceans are a big player. The endless storms

that circulate around the periphery of Antarctica drive a conveyor belt

of oceanic heat. While this place might be out of sight for most of

us, what happens here affects us all. Keeping Halley operational on

this particular ice shelf is critical, not just for monitoring

the weather. 60 years ago, it was cited here ah, long with numerous --

along with numerous aerials to investigate the interactions between

the earth and the sun. I'm Richard. I work at the British Antarctic

survey and I lead the space weather and atmosphere team. Halley is our

window on space, that's what we call it. I feel like the luckiest person

on earth really. Each winter at Halley, there's a dazzling display

of light, the Aurora australis. The Aurora are only possible at the

north and south poles because of the shape of the earth's magnetic fields

and by monitoring what goes on above our heads, Halley's location gives

us the opportunity to protect our modern world from the sun's

destructive activity. The flow of the planet's molten iron core is

what creates the earth's magnetic field. Field lines stretch out into

space, 60,000 kilometres facing the sun and trailing away some 400,000

kilometres on the dark side of the earth

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

they're disrupted by the sun's coronal mass ejections.

It emits billions of tonnes of charged particles and when they come

to the earth they see the earth's magnetic field as a barrier. But it

has a 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 are suddenly violently snapped back into place.

It's an earthquake in space, if you like. That process is the start of a

large geometic storm and the manifestation of that is that the

Aurora you see in the polar regions. But Halley isn't just under this

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

radio waves thrown out by those coronal mass ejikss. Our research

has shown those radio waves can accelerate charged particles up to

very high energies and damage the sprayscraft. We call them killer

electrons. They 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 these 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.

It's like a lightning bolt. They have been related to the loss of a

spacecraft, the total satellite loss, costing $250 million. That's a

lot of money. You think that there is something like 120 satellites on

orbit in total. The space weather research done here

is attempting to forecast the impact of geo mag yettic 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. Arguably back here on earth Halley's

most important work is to look out for signs of climate change.

Neil, this snow surface is almost perfect for skiing. Yeah, it's

absolutely great. It's lovely and sot -- lovely and soft. It's this

snow within the clean air sector that we have 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. When it's trapped by the snow falling here

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

Operations at Halley mean that purity is guaranteed.

There is no vehicles coming down here. The only way to get into this

area is to walk or ski. Right the suit is on. What's next? First of

all, we need a hole and that will take sometime. That will warm us up.

We are wearing these fetching overalls to prevent us contaminating

the snow samples. I am suffering for science!

Because the air here is so pure chemicals trapped in the snow reveal

historic climate change. 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. The snow sachls contain everything manmade 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 air monitoring equipment here is so

sensitive it can detect forest fires and volcanic eruptions as far away

as south America or Africa. Breathing the cleanest air on the

planet, I like that. The clean air lab is searching for evidence of

global warming. In particular, the greenhouse gases CO2 and methane.

Here we have the sample pipe, the air comes in, it goes into the

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

air outside. These are the real-time values we are seeing of what

actually are all greenhouse gases? Yes, as we know CO2 is one of the

main gases at the moment. It's about 390 per million. When I first

started it was around 375. It's probably increased by nearly 10% or

thereabouts. How can you be sure those levels that you are seeing

increasing are coming from human activity? The only way you can get a

large amount into the atmosphere is through volcano eruptions and there

hasn't been any large in the last 150 years. We can say it's more than

likely coming from fossil burns. Although volcanoes erupt all the

time there have been no major events for over a century and the present

concentration of atmospheric CO2 is higher than it has been for almost a

million years. But for atmospheric chemists it's also an indicator of

what can happen with a far more dangerous greenhouse gas, CH4, or

methamne. As you can see it's a lot less than CO22. We know that we are

putting more CO2 into the atmosphere. As the atmosphere warms

up the owings will warm up and as they warm up more CO26789 will come

off the oceans. If this reaps rising there is a chance that frost will

start to melt and with that we will get the release of methane. The

frost off the northern hemisphere across Russia and North America

holds vast amounts of methane within its frozen soil. This gas is an even

bigger threat than CO2. Methane even though it's smaller in

concentration, is 20 times more potent. In the future it 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

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 temperatures across the

Antarctic have risen by over three degrees over the last 60 years, more

than ten times the global average. Over the next century greenhouse

gases will drive further warming across Antarctic and the surrounding

seas. The work being done at Halley is vital. We need to understand

those processes to predict the impact of that future warming.

After an all too brief nine days on the ice shelf I am heading for home.

It's a bittersweet farewell to somewhere I am unlikely to ever see

again. I wasn't sure what it was going to

be like coming back here after all these years. What I found is a

landscape that's completely unchanged but an operation that's on

a different scale to what I experienced back in the early 80s.

It feels much more professional. The size is bigger, there is 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 would probably fall apart. But actually, I don't

know, it feels like I have come full circle. It's feeling like the end of

a journey that I started half a lifetime ago.

Hello. We have had lovely spells of sunshine