Metals in the Snow

Cat Cameron following careful procedure to take snow samples for metal analysis by scientists at the University of Plymouth, UK

Oh no (I hear you say) please, not another new story of contamination and its dreadful consequences!

And yet…

metals in the snow of the Antarctic Peninsula may be good news.

Ok, we’re not going to give industrial pollution a clean bill of health here: what I am talking about are metals that are essential nutrients for the primary producers at the base of the ocean food web: phytoplankton.

Metals are key components of biological molecules, including many enzymes and proteins (Figure 1). Here, they facilitate the chemical reactions that regulate living organisms, including all aspects of metabolism, such as breaking down food, synthesis of molecules and the transfer of energy.

"Lumenal domain of cytochrome f" by Nick960 is licensed under CC BY 2.0
Figure 1: Example of a biological molecule in plants: Cytochrome f is an electron transfer protein participating in oxygenic photosynthesis. The orange structure is the haem group that contains iron (Fe) that facilitates the energy (electron) transfer.“Lumenal domain of cytochrome f” by Nick960 is licensed under CC BY 2.0

Too much of a good thing causes harm, and in that case, we would talk about pollution. But not enough, and we are in the world of deficiency, or in the case of microalgae in the Southern Ocean, of limitation.

Instead of limitation, we want abundance in the Southern Ocean, not just on behalf of the ecosystem itself, but also for the whole of the global community: abundance here powers natural climate change mitigation, and we all know how much we need that right now.

Here is how it works:

The global carbon cycle is important for the Earth’s climate regulation, because carbon dioxide (CO2) in the atmosphere is a main contributor to the natural greenhouse effect that ensures temperatures on our planet are hospitable to life as we know it. But since the industrial revolution, human activities have greatly elevated CO2 levels in the atmosphere and these now amplify the natural greenhouse effect, leading to changes in climate and more frequent and severe, extreme weather events.

I trust that so far I’m not telling you anything new, but please bear with me…

The oceans are particularly important in climate regulation through absorption of excess heat, regulating temperature through global ocean currents and dissolution of atmospheric CO2 in surface waters. Phytoplankton utilise sunlight to photosynthesise and use the dissolved CO2 as carbon source to form their cell structures and multiply. In turn, they are consumed by grazers, which are consumed by predators…forming the base of the oceanic food web (Figure 2).

"Plastic Atlas - The oceans absorb a quarter of anthropogenic greenhouse emissions. Pollution by microplastics may put the biological carbon pump at risk. More research is needed." by boellstiftung is licensed under CC BY 2.0
Figure 2. Illustration of the draw-down of CO2 by phytoplankton and the downward movement of dead organic matter into the deep ocean and sediment. Cropped from an image in: “Plastic Atlas – The oceans absorb a quarter of anthropogenic greenhouse emissions. Pollution by microplastics may put the biological carbon pump at risk. More research is needed.” by boellstiftung is licensed under CC BY 2.0

How does this link to the expedition?

The main Antarctic deep water branch of the global ocean circulation system forms in the Weddell Sea (check ‘D’ in Figure 3), just off to the east of the Antarctic Peninsula. Here, surface water cools on the continental shelf and sinks – and the sinking water ‘exports’ the decay products and faeces of a myriad of organisms into the deep ocean and with it, exports the carbon originally captured by the phytoplankton.

"The Global Conveyor Belt – How the Ocean Stores CO2" by boellstiftung is licensed under CC BY-SA 2.0
Figure 3: “The Global Conveyor Belt – How the Ocean Stores CO2” by boellstiftung is licensed under CC BY-SA 2.0

However, the productivity of the Southern Ocean may be limited by the availability of essential metals, such as iron and manganese, because of the remoteness and ice cover of the location: there is little exposed land from which, at lower latitudes, nutrients are supplied to coastal seas. In other words, there could be more carbon export to the deep ocean, hence climate change mitigation, with a more plentiful supply of essential metals.

This is where ‘metals in snow‘ come in:

Weather systems transport air masses and moisture across great distances and entrained with these, particles and nutrients that are deposited on ice sheets, ice shelves and the ocean surface. This atmospheric deposition is an important pathway, by which essential element are transported.

Dr Simon Ussher and Dr Angela Milne at the University of Plymouth investigate the processes that determine the carbon export in that region. With analysis of the snow samples collected by the expedition team, Angela and Simon will be able to investigate the possibility that increased surface melting of snow and ice on the Antarctic Peninsula, could make a significant difference to the fluxes of nutrients and the productivity of the Southern Ocean.

Featured Image: Cat Cameron, secured by rope to Martin Densham, taking ‘pristine’ snow samples for later analysis by Angela and Simon, following their precise instructions and taking great care to avoid contamination. Photo (c) Antarctic Quest 21.

Read more about this project with links to further reading here.

Get live updates from the ice on Facebook and Instagram.

Many thanks to all of our friends, sponsors and supporters who are backing the Antarctic Quest 21 expedition NAAFI Team Army/Team Ethos Costain Group PLC BetterYou LtdApplied Satellite Technology LtdGreencastle Consulting Klättermusen AB Fjellpulken AS Polar Latitudes Clean Planet Energy PlanetLabs.Earth LikeToBe.org Emily Whitehead Charlotte Braungardt LGfL Devon and Plymouth Chamber of Commerce Prof Dr Ger Graus OBE Phil Carrotte Tim Ellis Twin Science & Robotics Verofax Limited Paul Read Martin Holland, FRGS Anjuli Selvakumaran Elliot Brown Watches Challenging Habitat

#wornbyadventurers #NAAFI1920 #TeamArmyUK #CostainGroup #betteryou_ltd #klattermusen #TheASTGroup #greencastleconsulting #Fjellpulken #expeditionfoods #polarlatitudes #theshackletonwhisky #rgs_ibg #ewhiteheaduk #unavco #oinkandsqueal #ragingbullbiltong #thegiftofoil #theludlownutcompany #ohso_goodforyou #nudiesnacks #pearlscakes #britanniaassociation #request2021#liketobe.org #ceraphienergy #AndrewSmedley PippaWhitehouse #AngelaMilne Simon Ussher #Nigel Marley #MichielvanDenBroeke #ImogenNapper

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