Alan Kennedy-Asser – Cabot Institute for the Environment blog

India heatwave: why the region should prepare for even more extreme heat in the near future

Posted on May 13, 2022March 29, 2023 by janet.crompton

An extreme heatwave in India and Pakistan has left more than a billion people in one of the most densely populated parts of the world facing temperatures well above 40℃. Although this has not broken all-time records for the regions, the hottest part of the year is yet to come.

Though the heatwave is already testing people’s ability to survive, and has led to crop failures and power blackouts, the really scary thing is that it could be worse: based on what has happened elsewhere at some point India is “due” an even more intense heatwave.

Together with a few other climate scientists, we recently looked for the most extreme heatwaves globally over the past 60 years – based on the greatest difference from expected temperature variability in that area, rather than by maximum heat alone. India and Pakistan do not feature in our results, now published in the journal Science Advances. Despite regularly having extremely high temperatures and levels of heat stress in absolute terms, when defined in terms of deviation from the local normal, heatwaves in India and Pakistan to date have not been all that extreme.

In fact, we highlighted India as a region with a particularly low greatest historical extreme. In the data we assessed, we didn’t find any heatwaves in India or Pakistan outside three standard deviations from the mean, when statistically such an event would be expected once every 30 or so years. The most severe heatwave we identified, in southeast Asia in 1998, was five standard deviations from the mean. An equivalent outlier heatwave in India today would mean temperatures of over 50℃ across large swaths of the country – such temperatures have only been seen at localised points so far.

Our work therefore suggests India may experience even more extreme heat. Assuming the statistical distribution of daily maximum temperatures is broadly the same across the world, statistically a record-breaking heatwave is likely to occur in India at some point. The region has not yet had reason to adapt to such temperatures, so may be particularly vulnerable.

Harvests and health

Although the current heatwave has not broken any all-time records, it is still exceptional. Many parts of India have experienced their hottest April on record. Such heat this early in the year will have devastating impacts on crops in a region where many rely on the wheat harvest both to eat and to earn a living. Usually, extreme heat in this area is closely followed by cooling monsoons – but these are still months away.

It is not just crop harvests that will bear the brunt, as heatwaves affect infrastructure, ecosystems and human health. The impacts on human health are complex as both meteorological factors (how hot and humid it is) and socioeconomic factors (how people live and how they are able to adapt) come into play. We do know that heat stress can lead to long-term health issues such as cardiovascular diseases, kidney failure, respiratory distress and liver failure, though we will be unable to know exactly how many people will die in this heatwave due to the lack of necessary health data from India and Pakistan.

What the future holds

To consider the impact of extreme heat over the next few decades, we have to look at both climate change and population growth, since it is a combination of the two that will amplify the human-health impacts of heat extremes in the Indian subcontinent.

world map with some countries shaded yellow — Hotspots of population increases over the next 50 years (red circles), all coincide with locations where no daily mortality data exists (yellow).
Mitchell, Nature Climate Change (2021), CC BY-SA

In our new study, we investigated how extremes are projected to increase in the future. We used a large ensemble of climate model simulations, which gave us many times more data than is available for the real world. We found that the statistical distribution of extremes, relative to a shift in the underlying climate as it generally gets warmer, does not change. In the climate models the daily temperature extremes increase at the same rate as the shift in the mean climate. The IPCC’s latest report stated that heat waves will become more intense and more frequent in south Asia this century. Our results support this.

The current heatwave is affecting over 1.5 billion people and over the next 50 years the population of the Indian subcontinent is projected to increase by a further 30%. That means hundreds of millions more people will be born into a region that is likely to experience more frequent and more severe heatwaves. With even larger numbers of people being affected by even greater heat extremes in the future, measures to adapt to climate change must be accelerated – urgently.

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This blog is written by Cabot Institute for the Environment members Dr Vikki Thompson, Senior Research Associate in Geographical Sciences, University of Bristol and Dr Alan Thomas Kennedy-Asser, Research Associate in Climate Science, University of Bristol.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why snow days are becoming increasingly rare in the UK

Posted on December 17, 2020April 4, 2023 by janet.crompton

A snowy start to the day at Watlington station, King’s Lynn. December 18 2009.
Lewis Collard/Wikipedia

Winter frost fairs were common on the frozen River Thames between the 17th and 19th centuries, but they’ve become unimaginable in our lifetime. Over decades and centuries, natural variability in the climate has plunged the UK into sub-zero temperatures from time to time. But global warming is tipping the odds away from the weather we once knew.

These days, people in the UK have become accustomed to much warmer, wetter winters. In fact, winter is warming faster than any other season. This is bad news for those holding out for a white Christmas – the Met Office reports that only four Christmases in over five decades recorded snow at more than 40% of UK weather stations.

Painting of people, tents and horse-drawn carriages on the frozen river.

A frost fair on the River Thames, painted by Thomas Wyke (1683-1684).
Thomas Wyke/Wikipedia

Christmas is a magical day for many, but meteorologically, it’s no different from other winter periods, when snow and ice are also becoming less common. The Met Office definition of a snow day at a given location in the UK is when snow lies on at least 50% of the ground at 9am. Currently, the Cairngorms around Aviemore receive over 70 snow-lying days per year – the most in the UK.

This amount is smaller than in previous decades though. Met Office data shows that, since 1979, the number of snow-lying days has generally decreased by up to five days per decade, and up to ten days per decade in the North Pennines, near Penrith. Around a fifth of the total area of the UK has experienced a significant drop in the prevalence of days with snow lying on the ground.

Two maps of the UK depicting the change in prevalence of snow days throughout the UK from 1971-2019.

Snow days are a rarer occasion in the UK today than they were five decades ago.
Met Office, Author provided

What causes snow days?

Snow days are often the result of a meandering jet stream, the fast-flowing current of air that’s between 9km and 16km above the Earth’s surface. The jet stream normally transports temperate weather from the Atlantic across the UK, but if it’s displaced southwards, it allows persistent high pressure systems of colder air from the north and east, originating in the Arctic or over the Eurasian continent, known as blocking high pressures, to settle over the UK for extended periods.

A number of atmospheric processes can cause the jet stream to meander, but perhaps the most dramatic is when the stratospheric polar vortex, a huge rotating air mass in the middle atmosphere, breaks down. This disruption causes the jet stream to weaken, leading to events such as the infamous 2018 Beast from the East, which brought widespread snowfall to the UK.

The winter of 2018 was not unique in this sense – 2009-2010 and 2013 both brought snowfall because of these dynamic “beasts”. So why is there still a decline in winter snow days in the UK?

The snows of yesteryear

There’s no strong evidence for a long-term trend in polar vortex disruptions, or other atmospheric processes that influence the jet stream. So the fact that people in the UK have fewer snow days to enjoy each year than they did in the past can’t be blamed on the invisible twists and turns above their heads.

But as the concentration of CO₂ in the atmosphere climbs, disruptions that do occur sit on top of increasing background temperatures, reducing the likelihood of the cold spells that bring widespread snowfall. Just as natural climate trends have lowered the severity of winters since the days of the frost fairs, man-made climate change will increasingly keep the UK’s average temperature above zero.

A heavy covering of snow can transform the country and our perception of it. Snow days, with the closures of schools and workplaces that they bring, evoke fond memories and bring out the child in many as hillslopes and parks become sledging highways. More tangibly, in Scotland, the snowsports industry is estimated to be worth over £30 million a year.

But wintry weather can be dangerous too. The cold affects our health, exacerbating heart and lung conditions and the spread of infectious diseases. In extreme cases, heavy snowfall can cause widespread livestock deaths, which happened in Northern Ireland in 2013. The inevitable disruption to travel and businesses can cause economic damage running into billions of pounds, with sectors like the construction industry halted entirely.

While the falling chances of a white Christmas might disappoint many, the current trajectory of less and less snow will at least come as a relief to some.

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This blog is written by Cabot Institute members Dr Alan Thomas Kennedy-Asser, Research Associate in Climate Science, University of Bristol; Dr Dann Mitchell, Met Office Co-Chair in Climate Hazards, University of Bristol, and Dr Eunice Lo, Research Associate in Climate Science, University of Bristol.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Dann Mitchell

Alan Kennedy-Asser

Eunice Lo

Frozen in time: reflections on a PhD and the history of Antarctica

Posted on April 20, 2020April 4, 2023 by janet.crompton

In March 2020, the third and final instalment of my PhD research made its way into Climate of the Past. In that article, I do my best to synthesise all I learnt over 5 years about an event that occurred 34 million years ago called the Eocene-Oligocene Transition. (Just so we are all on the same page: palaeoclimate scientists are interested in this period of the Earth’s history as it is when the first major Antarctic Ice Sheet appeared; before then Antarctica was warm and at least partially forested.)

An image of what Antarctica might have looked like at the onset of the Eocene-Oligocene Transition.

Four and a half years ago I wrote a piece for the Cabot Institute Blog about using a climate model to understand this point in the Earth’s history, and how many questions remained in our understanding. Why was the Earth so hot beforehand? What caused it to cool and eventually for Antarctica to glaciate? What other important changes would have occurred around the world at this time? At the time, I focussed particularly on the latter question.

The more time I spent trying to answer some of these questions, predictably (as is the way with science), the more complex some of them became. In the end, for my own peace of mind, I simply tried to bring together as much information as I could from lots of different sources to try to create a picture with some sort of clarity. I focussed on the high latitude Southern Hemisphere, because that is where a lot of the action was occurring at the Eocene-Oligocene Transition and it is also where models potentially have some difficulties in reproducing the climate.

To build up this picture, I used multiple climate model simulations of the period from two different modelling groups and compared these to the biggest dataset of proxy records of Southern Hemisphere climate 34 million years ago that I could compile by myself. Just reading and compiling all of the data from papers took me around a year. Not solidly (I had lots of other things to do too), but even still, reading papers solidly is very difficult in my opinion. Synthesising all of that different information into something coherent in my head is also something that I cannot force to happen quickly. It comes when it is ready.

Some of the complied proxy data for the high latitude Southern Hemisphere the Eocene-Oligocene Transition included in Kennedy-Asser et al. (2020).

In the end for this paper, I generated no primary data myself. It is all secondary data, either provided by other researchers I work with or taken from this very slow and lengthy review of scientific literature. Maybe, back at the start, that is not how I had pictured the finale of my thesis might look. Maybe the plan was to build up to some exceptional new result that I discovered, with data I produced with my own hands. But that wasn’t the case and, to be honest, I think it is better the way it is. Science is, and should be, a collaborative effort. In the spirit of this, I put all of the data I compiled and used, including all of my analysis scripts and detailed notes of where I obtained secondary data, up on the Open Science Framework. This way I hope the science can keep collaborating and continue growing.

Two thirds of my thesis were based on ‘my own’ data, messing around with a climate model, trying out new ideas, seeing if anything revolutionary popped out. This was really important too: for me to grow as a researcher, to learn about how the model works and to try to generate some outside-the-box ideas. Occasionally, of course, something truly revolutionary will be discovered. In the end, however, my conclusion is that model results often lack meaning by themselves: they need observations or proxy records to go with them to provide some sort of truth of what really happened, whether that is outside right now or 34 million years ago.

My new paper finds very similar things about why the Earth changed so much at the Eocene-Oligocene Transition to earlier research carried out nearly 20 years ago. It doesn’t challenge or rewrite everything we know, but that’s okay. The main scientific conclusion from my paper is that incorporating all of this data is actually essential to coming to the same conclusion as the research from many years ago. Without the inclusion of the boring, extensive data review, I might have quickly, excitedly jumped to a different conclusion that, on balance, seems less likely to be correct.

Much like this paper brings together different existing scientific data to compliment research built up over many years, it also brings together my own work and thoughts. It took many years, but it wouldn’t make sense to rush it: the conclusions take a bit of time, even if all of the data and answers are already out there.

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This blog is written by Cabot Institute member Alan Kennedy-Asser, a Research Associate at the School of Geographical Sciences, University of Bristol. You can follow Alan on Twitter @EzekielBoom.

Alan Kennedy-Asser

Antarctica: Looking back

Posted on May 11, 2019April 13, 2023 by janet.crompton

Back on dry land after seven-and-a-half weeks at sea, the sights of the Southern Ocean are already drifting from my mind into the whirlwind of modern life. The threats of land-sickness never materialised and the taste of fresh fruit and vegetables is everything I hoped it would be. Reflecting on a research cruise is not dissimilar to reflecting on a PhD.

“We only remember half”

Looking back can be a glorious thing. We all know the benefits that hindsight can bring. There are few things in our lives we couldn’t improve, whether they be things we said, research we carried out or ideas we had, if we got but one trial run at everything first. But looking back also gives the past a magical quality. The vividness of a blue sky intensifies, the significance of a rare sight swells and all the hardships are suppressed into one dense ball that our mind tries not to remember. The retelling of tales reconsolidates the good memories at the expense of the bad.

Of course this isn’t always the case and, if we really take the time, all of the gory details can be unpacked. I’m reading an amazing book at the moment, The Worst Journey in the World by Apsley Cherry-Garrard, that gives the most warts-and-all description of early Antarctic exploration. His descriptions are detailed, his wit hilarious and his tale harrowing. He is one of three who dragged two sleds to an emperor penguin colony in the heart of the Antarctic winter, being physically frozen into their clothes, losing their tent to a blizzard and of course getting plenty of frostbite. They did this just to collect three penguin eggs for science, as they hoped the embryos could be used to shed light on the evolutionary history of these creatures, which they believed were more primitive than other birds. The following year several of his closest friends died on the return leg of making it to the South Pole with Scott and he had to help recover their bodies.

Needless to say, Apsley didn’t have the greatest time in Antarctica, but still he writes:

Whatever merit there may be in going to the Antarctic, once there you must not credit yourself for being there. To spend a year in the hut at Cape Evans because you explore is no more laudable than to spend a month at Davos because you have consumption … It is just the most comfortable thing and the easiest thing to do under the circumstances.

This book is a definitive grim account of fieldwork and I really had nothing to complain about during our research cruise. To rephrase Apsley:

The [James Clark Ross], as [ships] go, was as palatial as is the Ritz, as hotels go.

A few nods towards monotony in work and some bad nights’ sleep in the previous blog articles in this series are all the negative memories I need to keep, otherwise the rest can go down for the record as one of the most interesting experiences of my PhD.

Southern Ocean Bridgeman Island Bridgeman Island off the Antarctic Peninsula. The sea was a bit choppy that day, but nothing too major to complain about.

Questions remain

I have just completed my PhD viva and, pending some minor corrections to my thesis, I have drawn a line under a four-and-a-half-year period of my life. During that time, most of my intellectual energy has gone into trying to understand what Antarctica was like in the past. Despite having been situated more or less in the same position over the South Pole for over 100 million years, this continent twice the size of Australia hasn’t always been the cold, inhospitable place that Apsley and co. experienced so brutally.

Fossils found on the few exposed outcrops of rock around the coast of the continent, on the sub-Antarctic islands and in the Transantarctic mountain range that cuts across between the Weddell and Ross Seas, show that up until relatively recently, diverse vegetation lived on this continent. (By relatively recently, I mean up until potentially 5 million years ago or so.) Definitely up until the end of the Eocene (the period I researched), much of the continent is believed to have been ice free.

The past environment of the Earth can be reconstructed using all sorts of complex chemistry and dating of past rocks and sediments, but the simplest and sometimes most compelling evidence can be those geological indicators that can be seen with the naked eye. Fossilised leaves, branches and seed pods from a variety of Southern Beech, most similar to modern Nothofagus Antarctica, show quite clearly what kind of ecosystem used to exist.

Nothofagus Antarctica and the Magellanic Forest, Southern Chile: a window into the past environment of Antarctica?

Nothofagus Antarctica and the Magellanic Forest, Southern Chile: a window into the past environment of Antarctica?

Today, Southern Beech forests can be found in Patagonia and other high latitude regions of the Southern Hemisphere. On our one day off we had in Punta Arenas before we set sail, I went with the other researchers from Exeter up into the Magellanic Forest Park just outside the town. As we walked through this ancient forest, snarled up in Old Man’s Beard lichen, with birds singing on a warm, sunny autumn day, I had to think ‘So this is what I (and lots of other people) have said Antarctica might have been like 34 million years ago?’

My research uses climate models to try to understand the processes that could explain the geological evidence of past climate. While there are some things they can help us understand reasonably well, there are other aspects of the Earth system that still remain difficult to explain, even after decades of research. How could the Earth remain warm enough to sustain forests over Antarctica and not freeze up? That is one such question which I can’t definitively answer.

My PhD research also focussed a lot on the importance of deep water formation on the regional temperatures in the Southern Ocean around the end of the Eocene. There could be little fieldwork more relevant therefore than going to try to understand deep water formation occurring around Antarctica today. Through conversations with researchers from all over the UK and beyond on the many long days of the cruise, I got an insight into the uncertainties that still exist in understanding this process today. Compared to the observational data we collected on our cruise, I looked at how the climate model we use compares in how it recreates the present day ocean. While there are some realistic elements, there are also some important differences which have planted future research questions in my brain. If these are the uncertainties in the model for the present day, how uncertain might my simulations of the ancient world be?

Crabeater seal in Antarctic pack ice. Understanding deep water formation remains challenging, in part because of how extreme the environment is.

Terra Australis Incognita

Looking back isn’t always easy. The deeper back in time we try to look, the harder it becomes to find data and to synthesise it with our knowledge of how the Earth and its oceans, atmosphere and biology work. In writing my PhD thesis, I had to come to terms with not knowing all of the answers. There are many, many questions that are too big and too complex to solve even with years of effort and 50,000 words. Stepping onto the James Clark Ross reminded me of that fact like a blast of 40 knot southerly Antarctic air to the face.

In the 17th Century, cartographers grappled with their limited understanding of this world, putting together the pieces of information they had and using artistic license to fill in the unmapped gaps that explorers had yet to reach. This map by Blaeu includes the Terra Australis Incognita, or ‘Unknown Southern Land’. While modern science would generally not approve of such guess work, exploring the history of the Earth system is a similar step into the unknown, with geologists, palaeoceanographers and palaeoclimatologists having to build the picture around what limited information they have.

A section of map by Blaeu (1645-1646), showing the as yet uncharted and hence imagined Terra Australis Incognita. Image courtesy of Special Collections, University of Bristol Library.

From 1646, when Blaeu’s map was published, it was a further 174 years before the first humans saw the Antarctic continent. Now, nearly 200 years on from that first sighting, the Unknown Southern Land still holds many secrets.

Still, looking back also shows how far we have come: a pleasant relief from thinking how far we have yet to go. We know so much more about Antarctica today than we ever have. Unfortunately, with hindsight, Apsley and co.’s journey to find emperor penguin eggs in the middle of winter was a relatively fruitless exercise as the hypothesis they were collecting the eggs to test has since been proven wrong: emperor penguins are actually very specialised and highly evolved birds, not primitive or reptile-like.

Should we give up because we might never know the answers or we might be going down a blind alley? I don’t think so. I’ll give the last words to Apsley, as he really, really earned them.

The question constantly put to us in civilization was and still is: ‘What is the use? Is there gold? Or is there coal? … The members of this expedition believed that it was worthwhile to discover new land and new life, to reach the Southern Pole of the Earth, to make elaborate meteorological and magnetic observations and extended geological surveys … They were prepared to suffer great hardship; and some of them died for their beliefs. …We travelled for science … in order that the world may have a little more knowledge, that it may build on what it knows instead of on what it thinks.

Apsley Cherry-Garrard in The Worst Journey in the World

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This blog is part of a blog series from Antarctica by Alan Kennedy-Asser, who has recently completed his PhD at the University of Bristol. This blog has been republished with kind permission from Alan. View the original blog. You can follow Alan on Twitter @EzekielBoom.

Alan Kennedy-Asser

Read part one of Alan’s Antarctica blog series – Antarctica: Ship life
Read part two of Alan’s Antarctica blog series – Antarctica: Why are we here again?
Read part three of Alan’s Antarcica blog series: Antarctica: Looking back

Antarctica: Why are we here again?

Posted on April 8, 2019April 13, 2023 by janet.crompton

The ship’s roll reaches 19° and everything falls off the desk, nearly followed by me off my chair if it weren’t for an evasive leap to one side. My roommate wakes with a start as the curtains around his bed have flung themselves open. “What are you doing?” he asks, in a confused state. Aside from the fact that everything falling off the desk was the weather’s fault, not mine, his question is a good one.

What are a team of 20 scientists, mostly from the UK, doing out here in the Southern Ocean? Surely there’s somewhere closer to home we could measure the sea. The main aim of this research cruise is to understand the process of deep water formation around Antarctica. First, let me briefly explain what deep water formation is and why it’s important in about 300 words. To understand this, the most important thing to remember is that water becomes denser when it is colder and/or when it is saltier. I think they teach that in GCSE science; if they don’t, they should.

Deep water formation

Antarctica is pretty cold, obviously. Where we are now, the sea temperature is around 1 °C. If we were to go further south or wait until winter, the sea will approach its freezing point of around -2 °C, forming sea ice. That’s a little colder than normal water, which freezes at 0 °C, because the sea is salty. However, when the sea freezes to form sea ice, the salt from the water is not incorporated into the ice – the salt that was in the sea water is left behind, making the remaining water a little bit saltier. As a result, the water close to the sea ice edge is both cold and salty compared to the rest of the world’s oceans, and therefore is denser than most of the rest of the world’s oceans. Dense water sinks below less dense water, and so the deepest water at the bottom of the oceans around the world all comes from around Antarctica.

Sea ice drifting close to the tip of the Antarctic Peninsula

When the water is at the surface of the sea, it can absorb heat and gases, including carbon dioxide, from the atmosphere. When deep water formation occurs, this heat and carbon dioxide can be drawn down into the depths of ocean, where it will stay for 1000 years or so. The research cruise I am on now wants to measure the amount of deep water formation occurring so we can better understand how much heat and carbon dioxide is being taken up by the ocean, which helps understand how much the climate will change in the future with global warming. That’s why we are here, basically, instead of the Bristol Channel.

Chlorofluorocarbons

Our team, based at the University of Exeter, are specifically measuring CFCs in the water. CFCs (chlorofluorocarbons) are manmade gases that were used for many industrial and commercial processes for a few decades before people realised they were destroying ozone in the atmosphere. This was creating a hole in the Earth’s ozone layer in the stratosphere over Antarctica and the Southern Hemisphere. Ozone is important for absorbing some of the Sun’s strong and damaging ultraviolet radiation before it reaches the Earth’s surface. Excessive ultraviolet radiation causes sunburn and skin cancer in humans, so people were concerned about the ozone hole when it was discovered in the 1980s. As a result, all nations of the world agreed the Montreal Protocol to stop producing CFCs that were destroying the ozone layer. Although this was a geopolitical and diplomatic success story, the ozone hole is only slowly showing signs of recovering and some CFCs still seem to be increasing (presumably suggesting some illegal production of them still occurs). However, luckily the ozone hole is no longer getting bigger and it is mostly contained to the very high Southern Hemisphere. Don’t worry, I brought plenty of factor 50 for my pasty Irish skin.

The reason we are measuring CFCs, however, is not actually to understand what they are doing to the ozone layer. We care about CFCs because they are manmade gases that are not naturally found in the atmosphere or ocean. This allows them to be used to trace ocean circulation and processes such as deep water formation. Let me explain how.

Jetsam

Since setting off from the Falklands five weeks ago, we have seen two manmade things: a ship on the horizon and some rusty metal oil barrels floating around amongst a heavy scattering of icebergs. The ship was a fishing boat, not far from the Falklands or Punta Arenas, so was not too surprising. The oil barrels however, were a bit more unexpected. They were floating right in the middle of the Weddell Sea, almost as far from civilisation as they could be. There were at least four of them, however they weren’t lashed together like some sort of raft made by Tom Hanks, they were all floating individually within a few hours steam of each other.

Oil barrel floating in the Weddell Sea, originally dumped around 6,000 km away (image credit: Hugh Venables, BAS)

The most curious thing about these barrels, however, is that when we were able to zoom in on a photo taken of one with a camera with a good telephoto lens, we could see their origin. They had writing and the branding from Operation Deepfreeze, a US mission to set up an Antarctic base in the Ross Sea in the 1950s. After initially being surprised at seeing any litter in the pristine Southern Ocean, we had to question how these barrels got here. The Ross Sea is on the entire other side of the Antarctic continent, around 6,000 km away by sea.

The Operation Deepfreeze base was built on the Ross Ice Shelf. This is thick ice that has flown out from the glaciers on land to create an area the size of France floating over the Ross Sea. Although this ice is very thick and reasonably slow moving, it is not permanent and does break off from time to time to form huge icebergs. The same process has formed some icebergs that have made the news recently, including one berg a quarter of the size of Wales and a potential berg break off that is threatening to take the British Antarctic Survey’s Halley research station with it. Well, presumably the old dumping ground from Operation Deepfreeze has at some stage broken off from the Ross Ice Shelf, floated halfway around the Southern Ocean carried by the Antarctic Circumpolar Current and been taken into the Weddell Sea gyre, where it melted and broke up, scattering all the rubbish into the Weddell Sea.

Just like these oil barrels can be used to trace how the ocean’s surface currents circulate (a similar story involves a spilt shipping container of rubber ducks in the Pacific Ocean in 1992), looking at where manmade gases such as CFCs end up in the deep ocean can tell us how the deep water formation takes water from the surface to depth. To measure the CFCs, we first take samples using a probe known as a CTD (which stands for Conductivity Temperature Depth). This probe has 24 bottles on it as well as instruments for measuring of salinity, temperature and other water properties. The probe is lowered to the bottom of the ocean (which around here can be more than 6 km deep) and as it is brought back up to the surface, the 24 bottles are closed at different depths. When the CTD arrives back on the ship’s deck, we then have samples of water from 24 depths through the ocean at that particular location. Over the course of the cruise, we will be carrying out around 100 CTDs.

Sampling using the CTD (lowered by winch off the side of the ship) continues morning, noon and night, meaning we work 12 hour shifts

With the water brought up in the bottles, our team takes a 500 ml sample from each and we store them in a walk-in fridge on the ship. We then analyse one sample at a time, which takes about 20 minutes using a custom-built machine that strips all the gases out of the water and calculates the amount of CFCs it contains. This setup for measuring CFCs is in its own portable lab, built in a shipping container that it strapped onto the aft deck of the James Clark Ross. While it’s pretty time-consuming running 100 CTDs with 24 bottles each taking 20 minutes (I calculate that to be more than 33 days of continually running the machine, assuming no delays) at least we have a good view from our container out over the wildlife and icebergs of the Southern Ocean.

Our CFC lab inside a shipping container, strapped onto the aft deck, as we sail by the South Orkney Islands

Other science

Besides our team measuring CFCs, other scientists are also using the water from the CTD to analyse oxygen isotopes, nutrient content, pH and microbes. When the CTD comes on deck, there is usually a bit of a mad scramble as everyone gets water for their own analysis, with a strict pecking order as who gets to take their water first. For maximum inconvenience, usually the CTD comes up just before dinner or lunch, just to make sampling that little bit more frantic.

Taking water samples for analysis from the 24 bottles on the CTD once it is back on deck (image credit: Charel Wohl, PML)

As well as measuring water from depth using the CTD, other scientists on the ship also continually measure the air and surface sea water as we sail. The air measurements, taken from the very front of the ship so not to get contaminated by exhaust or air conditioning fumes, must be measuring some of the cleanest air in the world. It’s pretty nice to stand up there and breathe it in, although it’s often accompanied by a blizzard of snow and biting wind, which makes the experience slightly less enjoyable.

We also have deployed some floats that will continue to measure the salinity and temperature of the sea here for the next five years or so. Using a gas bladder, these floats can adjust their density so they rise and sink through the ocean, measuring continually as they go. Every time these floats get back to the surface, they send their data back via a satellite connection. Although they don’t measure as much stuff as the scientists on the ship (for example, they don’t measure CFCs), they will be here all year round so keep making measurements through the winter. The ship on the other hand will have to retreat from the sea ice before the winter sets in, in case we end up repeating Shackleton’s antics with the Endurance. Which is fine with me because, interesting as it is, I don’t really fancy a further 6 months down here in the dark.

A float being deployed, which will continue to make measurements through the winter and for years after we leave

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This blog is part of a blog series from Antarctica by Alan Kennedy-Asser, who has recently completed his PhD at the University of Bristol. This blog has been republished with kind permission from Alan. View the original blog. You can follow Alan on Twitter @EzekielBoom.

Alan Kennedy-Asser

Antarctica: Ship life

Posted on March 25, 2019April 13, 2023 by janet.crompton

The RRS James Clark Ross docked in the Falkland Islands

Blinking blurry eyes, I crack open the curtains and gaze out into the bright light of a new day. A hulking white and blue iceberg gazes back at me. Even after a broken night’s sleep being shunted from one side of my bunk to the other as the ship bounces through swell, that still makes a rewarding start to each day. Through an unexpected turn of events, I’ve found myself on the British Antarctic Survey’s RRS James Clark Ross, on a seven-week long research cruise helping researchers from the University of Exeter take samples and measure CFCs in the Weddell Sea. Having just handed in my PhD thesis – after four years of studying and researching Antarctic climate and hearing the question “do you get to go to Antarctica?” countless times – the opportunity to help out on this cruise was too good an opportunity to pass up. Life on a ship gives you plenty of time to think (and write), but I promise to keep these musings brief in three posts: ship life; the science and why we’re here; and how the real thing compares to a PhD.
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This is my first experience of life on a ship. Previously, my most extensive experience of boat life was the eight hours on the Stena Line from Liverpool to Belfast, so I shall use that as my reference frame. Stena Line regularly ask you to fill out feedback forms and rate your experience to have the chance to win back the cost of your trip, so I shall do the same here (although as usual I don’t expect to win anything).

How did you find the booking procedure?

Stena Line have a fast and efficient website for making and managing bookings. Signing up for the research cruise was also pretty straight forward, although that was likely aided by me having done a PhD in Antarctic-related science and knowing someone at the British Antarctic Survey (BAS) who forwarded me the advert. I emailed the lead scientist from Exeter saying I was interested, we had a chat on Skype then I had to confirm that my PhD supervisors at Bristol were happy for me to go.

Generally, however, beyond that point there was a bit more faff than booking the Stena Line. BAS require quite a few forms filling out, some of which require a bit more homework, including passing a medical examination and a sea survival course. The authentic personal sea survival certificate had to be presented on getting on the boat before sailing. In contrast, the Stena Line rarely even ask for ID (although I suppose this might change after Brexit).

Stena Line: 5/5
James Clark Ross: 3/5

How did you find the check-in procedure?

The check-in for the Stena is remarkably simple, and as mentioned they rarely even ask for ID. Getting onto the James Clark Ross was logistically more complicated, requiring flights from Heathrow to Madrid, Madrid to Santiago in Chile, and Santiago to Punta Arenas. Although this journey took more than 24 hours, I still preferred it to driving in the rain up the M5 and M6 from Bristol, as I got free food and could watch films. Punta Arenas is also nicer than Birkenhead and I found the language barrier easier to overcome in Chile (Scouse can be very confusing at times).

Stena Line: 3/5
James Clark Ross: 4/5

Exploring the Magellanic forest above Punta Arenas

How did you find the cabins (if applicable)?

Getting a cabin on the Stena Line is not necessary, particularly if travelling during the day time sailing. The last time I travelled on the night time crossing, however, the cabin was not overly satisfactory with uncomfortable beds, an unclean bathroom and a broken soap dispenser. Stena customer services subsequently refunded the cost of the cabin. On the James Clark Ross, the cabins are slightly smaller than the Stena Line, however, there is ample storage space, the beds are pretty comfortable and there are privacy curtains for each bunk, which is good when you are on slightly different work shifts to your roommate. The biggest complaint about the James Clark Ross is that it makes many strange noises and rocks a lot more in the heavy weather, which can keep you up a lot of the night. These noises include a high-pitched wail which is either the stabiliser system or sirens luring us to our watery graves. The latter seems more likely.

Stena Line: 1/5
James Clark Ross: 3/5

How did you find the food onboard?

The Stena’s Met Grill is renowned for its fried breakfast and hearty lunch and dinner menu. The portion sizes are good, however, the prices are also a bit steep. On the James Clark Ross, three square meals a day are available (including midnight dinner service for those on night shifts), with lunch and dinner both offering 3+ courses. Because of how my shift patterns work out, it doesn’t make sense to get up for breakfast, so I just eat a 3-course lunch and dinner each day. Remarkably, over 4 weeks since we left, there is still fresh fruit and some salad on the go. The variety has been good, and they also have included some of the classics off the Stena Line menu, including fish and chips (most Fridays), curry (every Saturday) and Swedish meatballs. Although I have also had Swedish meatballs on the Stena, I have never tried authentic (Ikea) Swedish meatballs to know which is closer to the real deal.

Stena Line: 4/5
James Clark Ross: 5/5

How did you find the onboard shopping?

The shop onboard the Stena Line is pretty awful. They sell head phones if you forgot yours, which is about the only thing I have ever bought from it. They also sell some magazines and over-priced toys in case you didn’t realise the crossing was 8 hours and find yourself going slightly insane. The shop on the James Clark Ross, called the bond, is stocked with James Clark Ross branded clothing, toiletries, chocolate bars and some odds and ends like postcards and plaques. Unfortunately, as the ship is nearing the end of its working life for BAS, being replaced next year by the RRS Sir David Attenborough (of Boaty McBoatface fame), none of the branded clothing is being restocked. That means the only things that are left are in sizes XXL or age 7-8, neither of which are much use to me.

Stena Line: 1/5
James Clark Ross: 1/5

How did you find the onboard entertainment and facilities?

Both ships have a bar. The James Clark Ross bar is extremely cheap, however, many of the beers are about six months past their best before dates, which can result in ‘bowel roulette’ the following day. A worthwhile sacrifice if you’re unemployed like me. The lounge area is remarkably similar between both boats and is comfortable enough. The internet connection is much better on the Stena, although they possibly harvest your personal data in the process of providing it. On the James Clark Ross, they have to commit some of the internet to facilitate the science (boring), so the bandwidth for personal connections is not as strong.

Besides the gambling machines, the Stena Line’s main attraction is the cinema, which can be good if they have a decent film being shown. On the James Clark Ross, although they do not have a dedicated cinema room, they have a huge selection of DVDs and an endless supply of films available on people’s laptops which can all be put through a projector. There are also loads of board games and a few musical instruments onboard too, which are nice to have a jam on and facilitated a St Patrick’s Day gig and ceilidh dance. Although the James Clark Ross has a greater range of entertainment available, the Stena Line only has to keep you amused for 8 hours, not 7 weeks, so this one is a tight run context. Luckily when you have to work 12 hour shifts, you don’t have much time for entertainment.

Stena Line: 3/5
James Clark Ross: 4/5

St Patrick’s Day decorations in the bar

Would you recommend this crossing to a friend?

Usually my answer to this is ‘yes’ for the Stena Line. It’s a handy way of getting to England from Belfast, saving the drive through North Wales and up from Dublin. Admittedly there’s not much to see in the Irish Sea except the odd shearwater and the Isle of Mann, but generally the crossing is smooth because of the size of the ship (around 185m long) even when the weather is bad. On the James Clark Ross, the research cruise route very much agrees with the old saying ‘The adventure is in the journey, not the destination’. We are analysing a transect through the Southern Ocean and Weddell Sea and end at 57.5°S, 30°E, which is precisely in the middle of nowhere (go ahead and look it up on Google Maps). Although we don’t end anywhere in particular, the route has been spectacular at times: we’ve sailed past a number of sub-Antarctic islands, countless colossal icebergs, seen penguins on land, in the sea and on ice, had dolphins, fin whales, and humpbacks right by the ship (the latter breaching dramatically at times) and had regular, effortless fly-bys from wandering albatrosses and other seabirds great and small. The weather has been mixed and as the ship is 100m long it feels the swell a bit more than the Stena, however, the seas so far have been much more merciful than I had expected.

Humpbacks taking a breath, Coronation Island, South Orkneys

As exciting as it is to see the Isle of Mann and the Mourne Mountains, on the whole, I would say Antarctica just about tops the Irish Sea. Sorry Stena Line. Although, for health and safety reasons I’m sure the crew of the Stena Mersey are happy enough to not have to dodge all of these icebergs.

Stena Line: 4/5
James Clark Ross: 5/5

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This blog is part of a blog series from Antarctica by Alan Kennedy-Asser, who has recently completed his PhD at the University of Bristol. This blog has been republished with kind permission from Alan. View the original blog. You can follow Alan on Twitter @EzekielBoom.

Alan Kennedy-Asser