Darkness is falling and I’m on top of the research ship Maria S. Merian, On the bridge. This is the control center, with large windows providing an uninterrupted view of the stormy sea from all directions, and tall screens and maps showing data transmitted from inside, around, above and below the ship. It is very important to closely follow what nature is doing here in the open ocean. The lights are off so dark-adapted eyes can scan the waves, and the copilot uses the speakers to fill the space with smooth jazz and calm.
As the ship heads into a wave about 8 meters (26 ft) high, I grab the gunwale under the window with both hands, one leg on the table behind me, then dive down the other side. It looks like a big roller coaster; Immediately after the crest of the wave you feel like you are floating, and as the ship hits the trough you strain to withstand the additional force from the ground.
Although the images are dramatic, we are in the Labrador Sea because of something no human can see directly. In this northwestern corner of the Atlantic, between the southern tip of Greenland and Newfoundland, we can live for weeks in winter, in cold and constantly stormy weather, within a certain scientific phenomenon. We are here to learn about a process that is fundamental to the functioning of our planetary engine. The ocean around us literally takes a deep breath. The cooling between late November and February causes deep mixing between surface waters and deeper waters, facilitating the transport of vital gases. I am part of the UK contingent of an international team of scientists here to study how this happens.
Our seas are doing us a huge favor by removing additional carbon from the atmosphere
Our society tends to view big blue areas on maps as liquid filler with fish in them. Nothing could be further from the truth. The connected global ocean is an engine, a dynamic 3D system with constantly changing internal anatomy. to do things that shape the world we take for granted. It is a large reservoir for heat and gases: carbon dioxide (CO2), oxygen, nitrogen and more. Where the large surface of the sea touches the atmosphere, these gases can be transferred in both directions and their concentrations in water and air can change.
Near the equator, e.g. CO2 It comes out of the water to rejoin the atmosphere, where at high latitudes it goes the other way. These processes are not currently balanced; the ocean is taking in extra CO2 because we have increased the concentration in the atmosphere by burning fossil fuels and changing the land surface. Our seas are doing us a huge favor by removing additional carbon from the atmosphere, but we don’t understand the full details of this process at the surface or how this might change in the future.
Ocean breathing, which occurs in the Labrador Sea, is particularly important because it is one of the few areas where its surface is sometimes directly connected to its depths. In much of the global ocean, the upper layer of water (usually a few tens of meters thick) floats above the cooler, denser water below and remains well separated. But in winter in this corner of the North Atlantic, surface water gets so cold that sustained storms can stir the upper layer downwards so much. It’s like a gaping hole into the ocean depths – where anything that goes into the sea can continue to go downwards – and it forms a crucial part of what’s called “overturned circulation,” the slow global diversion of seawater between the surface and the depths. One consequence of this is that animals that live about two-thirds below the surface and never see sunlight, from tiny anglerfish to giant squids, can still breathe oxygen.
Major winter storms in this region add oxygen to surface water, which sinks downward, then moves sideways and into the rest of the Atlantic, oxygenating the entire middle layer of the ocean. But our best computer models of how much oxygen flows this way don’t match the data we actually measure. This is important because the entire global ocean is slowly losing oxygen; There is 2% less oxygen now than there was in the 1960s. To predict what will happen in the future and its consequences, we need to understand the conveyor belt that gets it there.
Maria S Merian It is a German research ship and there are 22 scientists and 24 crew members on board. Each team in this collaboration of researchers from Germany, Canada, the US and the UK examines a different aspect of the complex breathing process. The only way to make progress is to keep track of ocean physics and chemistry, as well as what the surface and atmosphere are doing, and then piece the data together to put the puzzle together when we return to land. There have been relatively few experiments that have been able to directly measure gases moving between the atmosphere and stormy open waters, and the last one (in which I was involved) was 10 years ago.
Ten years later, we have new and more accurate measurement tools and we know we need to examine a broader range of interconnected processes. This is a huge opportunity and we are all aware that it will not come again for a long time (due to logistics and resource reasons). None of these are easy: These are new experiments in a violent environment; There is no guarantee that anything you put overboard will come back safe or that the wind and waves will allow us to carry out our plans. Every data we receive is very valuable.
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There are two methods of measuring ocean breath; One of them is made from a tall pole perched on the bow of the ship, which monitors the smallest details of wind direction and CO2.2 concentration and the concentration based on measuring the inert tracer gases that we injected into the water 10 days ago (I am writing at the end of December) are now at a concentration of about one part per million. Some on board are constantly taking water samples, both from the surface as the ship zigzags and from various depths, mapping the 3D structures beneath us—bodies of water differentiated by temperature or salinity. Others have small underwater or surface vehicles that drift behind the ship or “fly” short missions in the water.
I measure the bubbles that emerge from waves breaking on the surface and how their size changes over time, because these are thought to accelerate the transfer of certain gases into the water. The challenge is that all the interesting bubble processes happen in the 2 to 3 meters at the top, but the surface itself often moves up and down 5 to 10 meters. To give me access to this strange upper layer, the mechanical engineering workshop at University College London, where I am based, built me a buoy that is essentially a large, hollow yellow rod that floats upright and is mostly submerged.
Nature is rich and beautiful but rarely orderly or useful, and we have to face it.
This provides a platform for my eyes and ears just below the waterline, which includes specialized bubble cameras, acoustic devices, and dissolved gas sensors. It can swim freely in rough seas for several days and keep track of everything around it. We only have seven hours of daylight, so the buoy is always deployed at night. It takes a large crane and seven people to launch it safely sideways, and then all you can see above the waves is the 2 meters overhead and its white flashing light.
There’s almost always full cloud cover, so the sky is black, the sea is black, and you can’t see where they’re touching. As the years of study and preparation fly by, the little twinkling light shines into the darkness, leaving only trust in engineering. The overhead beacon emails me every half hour to let me know where it is, chattering away in the background of my day as I try not to think about what 50 mph winds and up to 10-foot wave heights might do to the buoy. The relief we feel when we recover after a few days is overwhelming.
While we live in an age of technological surprises and constant information, data seems cheap. But our global ocean is huge, and there’s no easy way to scale up research into its interior. Marine science is still incredibly data poor, especially given that the sea is at the heart of every climate model. Computer models are extremely powerful, but their job is to match the measurements we make in the real world, and so we can only know how well the models are working if we have those critical numbers. That’s why it’s important to be out here in the complex real world, making difficult measurements and trying to challenge our understanding of what’s going on around us. Nature is rich and beautiful but rarely orderly or useful, and we have to face that.
Relating to: Why do we need to respect Earth’s last great wilderness: the ocean?
Hopefully the outcome of this project will be a much better understanding of the mechanisms that cause gases to move across the surface in stormy seas, and this will mean that we can calculate much more robust carbon and oxygen budgets for the oceans. This would add nothing to the strong arguments against burning fossil fuels; We already have enough science to know what we need to do to avoid the worst climate outcomes, and enough technology to mostly get us there.
But what this will do is help us understand and predict the changing ocean and make better decisions about how to manage the consequences of our past actions. We live on a water planet, and an honest assessment of our own identity needs to reflect this. Ignoring the sea is not an option, and therefore increasing our understanding of it is an important step on the path to a better future.
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The Blue Machine: How the Ocean Shapes Our World This piece by Helen Czerski is published by Transworld (£20). To support Guardian And Observer Order your copy at guardianbookshop.com. Delivery charges may apply