Month: February 2015

Life on the ice: Fieldwork in Antarctica

Posted on by janet.crompton

From early November last year, I was lucky enough to spend over two months doing fieldwork on Pine Island Glacier, an ice stream in West Antarctica, which is currently the largest single contributor to sea level rise. I was part of a twelve person team that made up the second iSTAR traverse.

iSTAR is a collaborative scientific programme, funded by the Natural Environment Research Council (NERC) and co-ordinated by the British Antarctic Survey (BAS). It aims to improve our understanding of the stability of the West Antarctic Ice Sheet, which could potentially undergo rapid retreat in the coming centuries. It is divided into two halves – half the programme is ocean focused, looking at how relatively warm Circumpolar Deep Water intrusions onto the continental shelf interact with the ice shelves in the Amundsen Sea. The University of Bristol is involved in the second half of the programme, which is concerned with the ice sheet dynamics and mass balance, particularly the changes happening to Pine Island Glacier (PIG). In order to study these changes, two traverses of PIG have been made, over two consecutive seasons (2013-14 and 2014-15). The 800 km traverse, took in 22 sites across the ice stream and its tributaries, where various scientific techniques were used to determine the properties of the ice, glacier bed and firn layer (compacted snow).

During this season, despite some strong winds, we successfully completed all the science we set out to do, included seven seismic surveys, ten shallow ice cores, 22 neutron probe snow density profiles and ten phase-sensitive radar profiles. For me, as a PhD student, it was a great experience to work with senior scientists in the field, and to be involved in such a wide range of field techniques.

The scientific goals of the iSTAR traverse could not been achieved without the use of the traverse logistics, which involved using Pisten Bully snow tractors to tow the caboose (a converted container that acts as kitchen and living space), equipment and fuel from site to site. This is a new way of field operation for BAS and is likely to feature in many more scientific programmes in the future, given the success of the two iSTAR traverses. Of course, there are some old-school field scientists who joke that we are the Caravan Club of Antarctica, but I think they are just jealous – eating pancakes for breakfast in the caboose has to beat sitting in a pyramid tent eating rehydrated rations!

On the move! Image credit: Isabel Nias
Despite the perhaps more luxurious living conditions than the average field party, living in the deep field on the ice was not without its challenges. We were still sleeping in tents and my standard answer to the question, “but how did you wash?” has been, “I didn’t”. At the beginning of the field season we had temperatures as cold as -35°C (plus wind chill), which froze your breath inside your nostrils. However, I preferred the cold to the “warm” temperatures we had towards the end of the field season (it hit 0°C at one point!), which made our boots and gloves all damp. The work was also physically hard. Each seismic survey was 7 km long, and involved a team of us drilling 30 hot water drill holes, which were then loaded with explosives, and digging over 700 holes to place the geophone sensors in the snow. Although it was worth it for the end product: an idea of the type of bedrock PIG is flowing over.

Before I arrived, I had heard from Steph Cornford, who was on the first iSTAR traverse, that the weather had been exceptionally pleasant last year, with plenty of blue skies and low winds. So much so that they ate their Christmas dinner outside! This year, the weather was more like what you would expect from Antarctica – we certainly had our fair share of strong winds, which hindered progress at times, especially due to the sensitivity of the seismic work to wind speed. I got very good at estimating the wind speed based on how much my tent was shaking, or by looking at the Union Jack flying from the caboose!

Emma Smith and Alex Brisbourne (BAS) making their way to the
safety of the caboose on New Year’s Day. Image credit: Alex Taylor.
New Year on PIG was certainly one to remember. We spent the evening doing a pub quiz in the caboose and seeing in the New Year with a whisky and a poor rendition of Auld Lang Syne. By 1:30 am, however, the winds had picked up to 50 knots with gusts of up to 65 knots, creating extreme white out conditions from all the blowing snow. Many of us who were still up decided to sleep in the caboose that night. I’m glad I did because I doubt I would have slept at all in my tent (from the noise and the fear that the tent would be ripped from its pitch!). The strong winds persisted well into New Year’s Day, but we were able to assess the damage. Rather than blowing away, my tent was actually half buried by a huge drift. However, it could have been worse – James’ tent was destroyed and completely filled with snow! It took the whole of the next day to get camp cleared again – is “shovelling snow” a worthy thing to put on my CV?

Looking back, it is not working until 3 am to finish a seismic line that I remember. Rather, it is the people, as well as all the amazing experiences I had, which stick in my mind. It’s not every day that you co-pilot a plane across West Antarctica or bake a Christmas cake on 1800 m thick ice.

I would like to thank iSTAR, BAS and all the guys at the Rothera Research Station for such an awesome experience. The real work starts now – we have a lot of data to work on! Have a look on the iSTAR website for more blog posts written while we were in the field.
The second iSTAR traverse team at Christmas, complete with a ratchet strap Christmas tree. Image credit: Alex Taylor
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Cabot Institute member Isabel Nias is a PhD student in the Bristol Glaciology Centre, School of Geographical Sciences at the University of Bristol.  Her PhD, which is funded through the NERC iSTAR programme, aims to use ice flow modelling to understand the sensitivity of the Amundsen Sea ice streams, and their potential impact on future sea level rise.
Isabel Nias

The challenges of global environmental change: Why we (Bristol) should ‘bridge the gap’

Posted on by janet.crompton

Our planet and the people who live upon it face profound challenges in the coming century. As our population, economies and aspirations grow we consume increasing amounts of precious and finite resource.  The side effects and waste products of this consumption also have profoundly negative impacts on our environment and climate, which  in a vicious circle will make it even harder to support our food, energy and water needs.


In order to live on this planet, we must bridge the gap between wasteful lifestyles based on limited resources to efficient lifestyles based on renewable ones. Nowhere is that more apparent than in our consumption of fossil fuels. Much of our prosperity over the past two centuries has derived from the exploitation of these geological gifts, but those gifts have and are causing climate change with potentially devastating consequences. These are likely to include more extreme weather, loss of marine ecosystems and droughts; in turn, these could cause famine, refugee crises and conflict. 


These climatic and environmental impacts will be felt locally in the European Green Capital as well as globally.  We live in an interconnected world, such that drought in North America will raise the price of our food. The floods of last winter could have been a warning of life in a hotter and wetter world.  Many of us in the South West live only a few metres above current sea level.  


In my own work with Cabot Institute colleagues, I have investigated not just how Earth’s climate might change but how it has changed in the past.  This shows that our climate forecasts are generally right when it comes to the temperature response to greenhouse gases, although perhaps they underestimate how much the poles will warm.  More concerning, Earth history reveals how complex our planet is; with dramatic biological and physical responses to past global warming events. During one such event 55 million years ago, rapid warming transformed our planet’s vegetation and water cycle: rivers in Spain that had carried fine grained silts suddenly carried boulders. And that ‘rapid’ warming event occurred over thousands to tens of thousands of years not two hundred a reminder of the unprecedented character of our current climate change experiment.

Flooding in Whiteladies Road, Bristol. Credit: Jim Freer



Consequently, despite our best understanding of some factors, climate change will make our world a more uncertain place, whether that be uncertainty in future rainfall, the frequency of hurricanes or the timing of sea level rise. This uncertainty is particularly problematic because it makes it so much harder for industry or nations to plan and thrive.  How do we ensure a robust and continuous food supply if we are unsure if the planet’s bread baskets will become wetter or dryer?  Or if we are unsure how our fisheries will respond to warmer, more acidic, more silt-choked oceans?


Underlying this uncertainty is a deep ethical question about who will bear the risk and the inequality issues hidden within our choices.  Most of us recognise that we are consuming the resources and polluting the environment of our children.  But the inequity is deeper than that it is not all of our children who will suffer but the children of the poorest and the most vulnerable.  Those whose homes are vulnerable to floods, who lack the resources to move or the political capacity to emigrate, who can barely afford nutritious food now, whose water supplies are already stretched and contaminated. 


Bristol in 2015 will not bridge the gap by despairing at these challenges, but we can lead in acknowledging them. We can lead in showing how to avoid the worst uncertainty and taking responsibility for the consequences of where our efforts fall short.  Most importantly, we can lead towards not just radical resiliency but inclusive resiliency. 

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This blog is by Prof Rich Pancost, Director of the Cabot Institute at the University of Bristol.

Prof Rich Pancost

Professor Dame Julia Slingo: Modelling climate risk

Posted on by janet.crompton

When Professor Dame Julia Slingo visited the Cabot Institute last week, her message was clear: We need to look at climate risk in real world contexts.

Dame Julia was in the city to receive a Cabot Institute Distinguished Fellowship, which involved giving a talk about her work as a world leading meteorologist and Chief Scientist at the Met Office.

One of the first things she highlighted was that climate change isn’t isolated from other pressures like population growth and limited resources, so we need to understand the risks it poses in a real world context. We need to define the effects it may have on the security of food, water, health and energy around the world, and use the science as a guide to define an evidence-based and cost effective plan of action going forward. This, she said, is “one of the greatest challenges of the 21st century”.

Are we making extreme weather worse?

Today, the huge global population boom is putting an ever increasing strain on limited resources like land and water, which are also at risk from the cyclical climate variations that occur naturally. The big and controversial question is whether climate change caused by human activity has exacerbated the problem.

Dame Julia described an annual report produced by the American Meteorological Society (AMS) that analyses extreme weather events around the world each year, aiming to determine whether the effects were magnified by anthropogenic climate change. As she pointed out, it is important that we recognise that not every bit of bad weather can be attributed to climate change, however the AMS often do find that we have played a role in making the situation worse.

One example she picked out was 2012’s Hurricane Sandy, which killed 233 people across eight countries in central and north America. The AMS report found that if sea level had been at the level that it was 50 years ago, the devastating effects of the storm would not have been as bad. It also suggested that continuing on our current path of climate change will mean minor storms will have increasingly severe impacts, leading to Sandy-level hurricanes more frequently in the future.

“We need a more nuanced discussion”

Last year was the warmest on UK record, making a total of 8 out of 10 of our hottest years having occurred since 2002. While of course there is variability in our climate from year to year and even decade to decade, intricate scientific climate models have shown that these record-breaking UK temperatures are made ten times more likely due to anthropogenic climate change.

While we may prefer a hot summer, temperatures don’t change uniformly across the entire planet. Worryingly, the Arctic is warming twice as fast as the rest of the planet, leading to a huge decrease in the amount of sea ice cover and corresponding sea level rise, which is already threatening communities living on low lying islands. Dame Julia reminded us all that it’s not as simple as trying to prevent a 2°C global temperature increase. The danger that climate change poses depends on who you are and where you live, and we need models to show what the risks will be.

Predicting climate risk

So how can we predict what the effects of climate change will be across the world? It begins with having a sophisticated model of the current global system. The Met Office has led decades of climate modelling, producing incredibly sophisticated simulations of climate systems on both short term (weather) and long term (climate change) scales.

I was absolutely amazed by the intricacy of these models. Millions of lines of computer code recreate the true physical nature of the planet, to the extent where large scale meteorological patterns like El Niño are emergent properties of the model, that is to say that they are a result of the basic physics encoded in the model, rather than being specifically programmed into it.

By altering the model with new data taken from the present extent of climate change or its predicted level in the future, the Met Office can model the global response at incredible resolution, showing the specific risks posed with increasingly detailed clarity (while still incorporating the inherent uncertainties present in all models). These models can then be used to test potential mitigation approaches and of course inform the global communities of the dangers they face.

What can we do?

Dame Julia explained that her role as Chief Scientist is to determine the needs of the people around the world, their risk tolerance and the information they require to make their own decisions. Science, she says, has a lot to offer in enabling governments to make wise, informed and efficient decisions with how best to spend their funds within the wider context of other societal issues, upholding the global securities of food, water, health and energy for the future.

Flooded Pakistan



Image: “There is no evidence to counter the basic premise that a warmer world will lead to more intense daily and hourly rain events” – Professor Dame Julia Slingo


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This blog is written by Cabot Institute member Sarah Jose, Biological Sciences, University of Bristol.

 
Sarah Jose
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