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Earth Reporters: Sea Change

Updated Saturday, 14th May 2011

Episode two: Tasmania-based Earth Reporter, Dr Susan Wijffels is one of a handful oceanographers worldwide piecing together crucial new insights into the way the oceans work

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Fish swimming in the ocean Copyrighted  image Icon Copyright: ReefVid In the past generation, the science of our seas has undergone a revolution. As the ice caps melt and coral reefs face destruction, the urgency to understand our oceans has never been greater. They cover 72 per cent of the earth’s surface, yet the ways in which they affect our changing weather patterns are only just being discovered.

This year, the launch of a NASA satellite to measure surface salinity will be a critical new development, a compliment to the existing global array of 3000 sea-data gathering robots that beam data signals to a central satellite controlled from Toulouse. These floats have revolutionised the way in which oceans are monitored – but what clues do their findings give to understanding our changing climate? With the challenges of extreme weather ever pressing, further mapping is a race against time.

This episode profiles these extraordinary developments in oceanography and follows Dr Susan Wijffels from her home in Tasmania to Argentina where she leads a mission of international scientists who are working with these technologies to provide a deeper understanding of what climate change really means.


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Narrator: In the past generation, the science of our seas has undergone a revolution. As the ice caps melt and coral reefs face destruction, the urgency to understand our oceans has never been greater.

At the heart of the world-changing discoveries being made, is a global team led by this woman. Heading an extraordinary network of some the world’s top oceanographers, this film will follow her as she leads a mission in South America.

Susan Wijffels: But we still need to complete the core mission and sustain the array.

Narrator: Working to extend the new system of science that is providing crucial clues in our understanding of extreme weather.

Dean Roemmich: What we are trying to do is to simply understand climate well enough that we can convince everyone that we know how the climate system is varying and changing on long time scales.

Susan Wijffels: It’s only through that international partnership and using lots of new technologies that we’re gonna be able to get the information we need about how the ocean is changing and evolving.

Narrator: In this episode, Dr Susan Wijffels is our Earth Reporter and this is her story…

Susan Wijffels: One thing I’m really interested in is how the ocean is changing, especially over long timescales. What we’ve been working on is taking data from the modern ocean observing systems – so what the modern ocean looks like and comparing it to what the ocean looked like 10, 20, 30, 40 or 50 years ago. We can look at the patterns of change and the rates of change and compare that with the models that we use to predict future climate how well they do for the last 50 years

We are having to do data archeology and almost detective work to understand how to use that older information.

We are the only people that can measure the 1990’s or the 2000’s and those times are never going to come back and the state of the ocean will have changed into the future. We should care about the oceans because they really determine our weather and climate that we live in, our environment. It’s those oceans those anchors of our climate system, the flywheel of our climate system they are going to be basically dictating our future to some extent.

Susan Wijffels: What got me into oceanography is that I was always a bit of science nerd in high school, so I got interested in the science of the planets and understanding how they worked and then I started thinking about the earth as a planet and a system and so in that way I started reading about how our climate system worked and in particular the role of the ocean.

Narrator: Susan’s passion has now put her at the heart of one of the most important areas of scientific discovery.

Unnoticed by many outside a close-knit circle of oceanographers, a global network has been created using thousands of remote controlled robots to monitor for the first time dramatic changes in the oceans. These robots have to bring in vital information from oceans which cover more than 72 per cent of the world’s surface.

Susan Wijffels: We are making a huge map, it’s a map of the oceans.

If you look at the surface of the seas, they have peaks and troughs just like the land. If you look below the waves, you see a whole new landscape. All oceans have huge currents carrying warm and cold water around the globe.

Driven by winds and the cycles of change in temperature and salinity within the water, they have a huge influence on the patterns of the weather around the world.

Measuring the currents helps us understand how heat moves around the ocean and to learn more about its impact on the climate.

I think one of challenges we have is we’re trying to get as close to the surface as we can but we don’t know the bottom depth so well.

Pete: We just need to know what’s the height or the lowest point we can keep this top instrument at.

Susan Wijffels: As an oceanographer, an important aspect of my work is to measure the ocean currents. The currents reflect the circulation of the ocean and how it moves heat around the planet, and so we really need to understand the circulation in order to understand the oceans role in maintaining our climate.

Narrator: Susan’s team have been discovering how the ocean currents of Indonesia – including islands off East Timor – influence the variability of the climate in Australia – such as 2011’s dramatic floods.But if you are measuring the ocean, you’ve got to have the instruments that are capable of beaming the data back to you – it’s a major logistical exercise.

Susan Wijffels: That’s what we’re doing here, we’re building instruments and moorings to measure and monitor that really important flow for our climate.

It’s a big engineering challenge and that’s why we need to be using things like this, which is a component of a deep ocean mooring where we have to use strong steel cables and large floats to put our instruments on.

Narrator: And these are the 2m long robots that have revolutionized ocean science.They cost 10,000 dollars each and there are new ones being deployed constantly to beam back new data to scientists across the world.

These robots of the sea are known as Argo floats.They have changed everything…

Dean Roemmich: It’s taken us a long time to get where we are today in observing the oceans because the technologies that were needed to get to where we are did not exist 20 years ago. These are technologies of autonomous instruments that can operate unattended by themselves out on the ocean freely drifting for periods of years…

Susan Wijffels: As these Argo floats drift, they collect temperature and salinity measurements up to a depth of 2000m – essential information for scientists to better understand the changes that are taking place in within the seas.

Over the last 50 years, there are some very clear things that we can see have changed in the ocean. The first most prominent one is that it’s warmed. At the surface has seen a broad warming of the ocean of the ocean that tracks the warming of the land…

Susan Wijffels: Argo is what we call a broadscale observing system, its mapping the broadscale structure of the ocean and how it varies and changes….

The idea is to take these very simple robots, we call them profiling floats and we want to put one of these floats out in ocean, one float every 300km in latitude and longtitude

Susan Wijffels: When we deploy our floats, they drop down to their drift depth of 1km and drift like a hot air balloon does on slow moving currents in the deep sea for up to nine days.

At the end of the ninth day, the float drops down even further to 2km depth, and switches on its sensor package, measuring temperature and salinity all the way to the surface of the ocean. This is the part that’s sitting up out of the ocean when it surfaces, rest of it largely stays submerged. This probe beams the information collected to a satellite system that geo-locates the float and delivers the data to a ground station. The cycle is repeated every 10 days for between five and nine years

Accuracy in the argo data set is really important, we really need to be confident in the observed rates of change of the ocean so it’s essential that we remove any problems with the data set so we have great confidence in the observed rates of change. Unusual among research projects, this real-time data is made freely available on the internet within 24hrs.

We have 3000 of these floats now telling us what the vertical temperature profile is in the ocean and then we take that information and we can build month by month a picture of where the heat is building up in the ocean or where the ocean is cooling down – and that in turn feeds back to climate variability. Things like is the ocean pre-conditioned for an El Nino to happen? Is the deep ocean keeping very warm so that might give us a much warmer summer or warmer winter that we would expect normally. So it tells us if things are hotter or colder than normal.

Another major change we are seeing from Argo data is an increasing contrast between the salty areas and the fresh areas of the ocean. Those changes are telling us the water cycle – the movement of moisture through the atmosphere that feeds our rainfall – has intensified, which means it’s becoming dryer in dry regions and wetter in wet regions.

Susan Wijffels: We are starting to really now see very clear patterns of that long term change in the ocean and Argo has been a key facilitator in that because have such a clear modern baseline on which to compare our older data.

Narrator: Thanks in no small part to the Argo robot floats, the evidence they collect makes the role of oceanographers central to understanding the most important changes in the world’s climate.

Howard Freeland: This is the only mechanism we have available for monitoring the ocean’s heat content, we know heat is changing in the climate system and 90% of this change is occurring in the oceans – and Argo is the only game in town, it’s the only mechanism we have to monitor this.

Dean Roemmich: What we’re trying to do is to simply understand climate well enough that we can convince everyone that we know how the climate system is varying and changing on long timescales so that the predictions of what the climate will be in 20 or 50 years start to have real credibility and they can affect the decision making that goes on by our society and our governments.

Narrator: But there are gaps in the system and Susan and her colleagues worldwide are now in a race to close those gaps.

Susan Wijffels: Consistent coverage of the Argo array is extremely important because we don’t want any gaps or holes opening up where we have to guess or somehow in fill what’s going on – we want to directly measure it and keep the uncertainty down.

Narrator: There are gaps in the system in the Arctic and Antarctic, gaps in the Southern Ocean and gaps caused by politics and bureaucracy in some countries who still need convincing to come on board. And there are gaps caused by pirates…

Anne Thresher: I need to bring you up to speed about our deployments…We’ve applied for permission to deploy in the EEZ of the Seychelles but they’ve denied it on the basis of piracy – it’s too dangerous to send a ship up there. The boundary I got for piracy area looks like that.. it’s a huge area.

Susan Wijffels: I’m amazed at how huge that risk area is. We simply can’t put the deployment vessels at risk at all.

Narrator: With a quarter of the Indian Ocean now a no go zone due to piracy - 30 floats need relocating…

Anne Thresher: The challenge of deploying floats in the Seychelles area in that region in general is getting a deployment opportunity as it can take months to get permissions to deploy in the EEZ’s of the Seychelles or France and the ship that we are chartering to do those deployments was there and said ‘no problem’ and of course things change, and the pirates widen their area of operation and the Seychelles refuse permission for very good reasons.

Narrator: In land-locked Toulouse in Southern France, the Argo programme is independently coordinated. Its satellites are monitored at a high-tech nerve centre twenty-four hours a day. And as a large international collaboration, it’s critical to keep the programme functioning smoothly…

Mathieu Belbeoch: The Main challenge of Argo is getting those instruments to sea. They live four or five years so can make 150, 10 day cycles so need to renew every year part of the array, basically we need to deploy 800 units a year, so that’s a huge logistical challenge, one of activities of the Argo Information Centre is to help scientists get floats in ocean.

Narrator: Despite seventeen thousand, three hundred kilometers separating them, these French and Australian colleagues are in regular contact and work side by side…

Susan Wijffels: As you know it’s been difficult to find vessels to go into some parts of the Indian ocean, right Anne.

Anne Thresher: Yes, it’s been hard

Mathieu Belbeoch: It appears a quarter of the Indian ocean is closed to the GOOS implementation

Anne Thresher: That’s a big shock, that’s a huge area.

Mathieu Belbeoch: I ask myself what we can do here at the Argo information centre to better help you implementing the Argo programme on a national basis, for me the most important is getting the instruments at sea, that’s still the challenge and probably always will for Argo.

Susan Wijffels: One of Argo’s greatest challenges is sustaining the core coverage of the array. If we have large holes opening up in the array, we cease to have a seamless time series and a record of how oceans have changed and our climate system is changing…

Narrator: It’s critical to maintain the international dimension of Argo – no single nation can monitor the ocean on their own.

Annually, world leading scientists gather to discuss the future of the project – In a bid to encourage South American countries to sign up and support the programme, this time it’s in Argentina.

As Co-Chair, Susan is responsible for leading a large part of this meeting…

Susan Wijffels: So here I am in Buenos Aires. I’m here to meet with my colleagues on the Argo steering team some of whom I’ve been working with for ten years now.

Meeting face to face with the Argo team every year is really essential to get to hear about how each programme is working towards the goal of implementing the global array and all the different problems that different nations face and figuring out how we can reach common goals is one of the key things about the meeting.

Narrator: For all the scientists gathering in Buenos Aires, it’s a critical time to discuss the Argo project’s future.

Susan Wijffels: Catching up with colleagues away from the main event is a vital part of the mission. Professor Dean Roemmich of Scripps Institution in California is one of the original innovators of Argo and helped conceive the concept. He’s also my Co-Chair…

Howard Freeland: How secure is Australian funding?

Susan Wijffels: The thorny issue is operationalising Argo funding is still up in the air.

Dean Roemmich: You don’t see a way forward on that yet?

Susan Wijffels: I don’t know what the answer is I’m finding hard to move on that issue

Dean Roemmich: I’m wondering if people have any new ideas about getting floats into the Southern Ocean, that’s always been the elephant in the room as far as coverage goes.

Howard Freeland: The big challenge is the vehicle to get them there

Dean Roemmich: Especially if we are successful in building longer life floats that we can support a 4000 float array, rather than a 3000 float array for example then we’ve really got enough floats – the question is how do we get them there?

Susan Wijffels: What I’m hoping for from the meeting is for us to have some certainty that over the next year or two we will be able to maintain the Argo array – and so that’s all around discussions of whether national programmes feel their funding is secure and have enough resources lined up.

Actuality: State your role and your home base…(countries introduce themselves)

Dean Roemmich: This is the group that is responsible for the international co-ordination of about 25 national Argo programmes that each make contributions…

Actuality: More introductions

Jon Turton: At the Met Office, we run forecasting models to predict conditions from seasons ahead to several years ahead. Argo is the observing system that gives us that information and allows us to initialise those models and make predictions on those timescales that have some degree of scale.

M. Ravichandran: Argo system we are using for the better monsoon forecast system

Susan Wijffels: It’s terrific the steering team is meeting here in South America for the first time, largely because Argo really needs to increase the number of partners internationally so we’re trying to welcome as many nations as possible into the global programme. We still need to complete the core mission and sustain the array which still remains a challenge for many of our national programmes. We need to broaden the support base for Argo by having new partners and new countries join to really broaden the support base and make it more robust.

Narrator: With each float lasting between five and nine years, annually at least 800 new floats need to be deployed – a huge logistical challenge.

Mathieu Belbeoch: 800 deployed last year, we still have a deficit of 300 units which means if we are to catch up with that, it means we need to deploy 1100 floats this year. I think the co-operation and the deployment planning is crucial this year…

We have about 30 countries implementing the programme, it’s not enough. We need more, we need more assistance from the continent, the South American continent to get more instruments at sea to maintain the array but also if we want to expand it as we planned to do in the future, we need more involvement of this region in the programme.

Narrator: Each floats costs $30,000 to make and run – the entire programme comes in annually at a cost of 24 million dollars. Funding this important project is an ongoing quest.

Howard Freeland: Biggest challenge to maintaining a global programme is getting money from national governments, getting the commitment from our political masters to support a big international effort to monitor the state of this planet. I really hope we can leave something worthwhile to future generations. At least we should leave knowledge of what we’ve done to it.

Narrator: After 4 days of discussion and debate, the outcome of the annual Argo mission was good news…

Susan Wijffels: We’ve found out that for the next year, we have enough resources to maintain the global array and prevent any large holes opening up in it which is terrific because many programme only get funding year to year – we are never sure if we can meet our goals.

The second thing is that that Brazil may come on on board… and join argo to support it because we need to broaden the partnership that underpins the Argo programme.

Only through that international partnership and using lots of new technologies will we get the information we need about how the ocean is changing and evolving to help us better predict climate, understand monsoons… and track long term changes in the ocean…. We need to use very new and complex technologies to monitor really remote parts of the global ocean

Narrator: The launch of the Satellite Aquarius, is an exciting new development in mapping the surface of the ocean, it’s complimentary to the Argo robots, serving the growing observation of the entire global ocean.

Dean Roemmich: When we look back on this period from the future, its clearly going to look like a revolutionary change, from an era 20 years ago when we depended entirely on ships for high quality measurements of the ocean to the present day where an integrated ocean observing system includes research vessels, satellites and thousands of autonomous instruments that are making many kinds of measurements all over the world at once, this will be a revolutionary change in our view of the oceans.

Jon Turton: Policies that government introduces really need to be underpinned by good strong science and Argo gives us the observations and measurements of what is happening in the oceans to be able to do that science and make sure then that good science underpins policy decisions that ultimately affect everybody.

Susan Wijffels: A robust global ocean observation system is essential – and through this, the gaps in our understanding of the oceans are being filled.

Future generations need this information and it’s urgent that we gather in now because our oceans are changing and we need to understand that change and where it‘s going to take us into the future.

I do worry about the future and the future of my daughter.

I feel quite strongly that observations are one of the most fundamental things about science

What I’m doing now and how the things we are learning about the earth’s system is going to assist her and future generations in managing with life and the environment, that’s also an inspiration in the sense that we really want to get a better handle on what’s happening so there are no bad surprises in the future…

Narrator: Anyone can be an Earth Reporter, to find out more about how to join the global conversation, go to





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