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Antarctica 2022 - Overview

Antarctica 2022 - Overview and Background

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Every winter, two metre thick ice forms from the ocean surrounding Antarctica to effectively double the size of the continent. I've been studying the layer of ice crystals that accumulate beneath this sea ice, known as the sub-ice platelet layer for the past several years. These disc-shaped crystals of ice are created in ‘supercooled’ water and float upwards to form a layer with an open lattice-like structure that can be several metres thick. Platelet ice performs an important role as a protective environment for ice-associated algae and the developmental stages of Antarctic Silverfish - a keystone species of the Ross Sea. In this new project, we are seeking to understand the distribution of the platelet layer under the ice in the Southwestern Ross Sea, and how this will change as our climate shifts. Our team at NIWA, principally Dr Craig Stewart, have developed a bespoke engineered solution known as the Sympagic Sampler. This is a huge drill that collects large cylinder-shaped sa...
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Phew! What a day!

I'm writing this at 1 am. I've had three hours sleep after crashing into bed at 10 pm. But yesterday was such a big day that I've woken up in the middle of the night excited to write about it… The day prior had been useful but ultimately unsuccessful. While Jacqui and Svenja remained at camp to process the samples from Wednesday; and Craig, Ollie, and Greg headed west to redeploy our seafloor-mounted mooring; Ken, Neill, Nina, and I ventured onto the new ice to attempt our high-resolution platelet cores, all under the watchful eyes and ears of Vanessa and Adam's cameras and microphones. This meant using the platelet coring system to collect our samples in 25 cm segments, giving us a sense of what we're missing when we later reduce down to only three samples per core. Everything had been going surprisingly smoothly, right up to the point where it came time to siphon off the first of the sub-samples. Things had been going so well, and the weather so amenable, th...
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Shovelling Snow…

Wind chill is a major hazard in Antarctica – even a relatively mild -10 degrees can become dangerous when the wind gets up. The wind can also get the snow skating across the surface of the ice – the faster the wind, the more snow it is capable of moving. When the entire plane of ice, as far as one can see, is subjected to this type of wind, it can be quite a beautiful sight. And all the more so when it is lit by late and low evening light: the surface becomes a sparkling and moving luminous hazy carpet. We've just had ~48 hours of continuous wind like this, with the snow skating across the surface for the better part of Friday night through Sunday afternoon. A few steps away from the camp brings a fairly unique perspective – standing amid a wide, shallow river of snow, and the only part not in constant movement as far as the eye can see is within the wind shadow of the camp itself. The wind shadow stretches for several kilometres, leaving a narrow wedge of undisturbed surface. ...
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A very special visitor: The PM comes to Camp K892

I've been fortunate to enjoy many unique opportunities as a result of being involved in Antarctic research. But the chance to give New Zealand's Prime Minister a hands-on experience of science at my containerised field camp is a pretty remarkable stand-out. Our PM was 'treated' to the full Antarctic experience… her initial attempt to fly south on the NZDF C-130 Herc got part-way here but had to return to Christchurch on account of the conditions of weather and visibility here at Phoenix airfield – an Antarctic 'boomerang' flight. On the same day, the USAF C-17 had been able to land with a combination of cargo and personnel on board – including our very own Vanessa and Adam, as well as a couple of the PM's entourage. So, after waiting for the night in Christchurch, Ms Adern did make it down the following day on the USAF C-17 with the remainder of her crew, including her partner Clarke Gayford and some of the AntNZ board members. She was then taken on a wh...
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Woop woop! We got the mooring back!

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Updated 8-11-2022 with photos during a short visit back to Scott Base Happy days! A major and ambitious milestone has been achieved! Last season, when we were here to test the platelet coring system, we deployed a brand-new type of oceanographic mooring with an experimental design. A 'mooring' just means a string of instruments suspended through the water column and programmed to keep collecting data for as long as possible. This is standard operating procedure for ship-based oceanography but is rather a different prospect in our situation, primarily because we have non-permanent sea ice cover to contend with. It is usual for us to deploy a mooring, but to only leave it in the water for the period that we're actually in Antarctica conducting the science. We'll drill a hole in the sea ice, mount a tripod over it, then suspend a weighted line with instruments attached down into the water column. When we've completed the rest of the work, we return to the mooring sit...
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Science Bite: The ocean connects Antarctica’s two types of ice

So, what are we actually doing out here? Even by Antarctic standards, McMurdo Sound is in a very special location – it's the most southern point on the planet where there is open water. In summer, that is. Come winter, McMurdo Sound is filled with sea ice that is locked to the land on both coasts and pressed up against the 'ice shelf' to the south. Stretching away from here, nearly 1,000 km to the south and about 1,000 km to the East, lies the great Ross Ice Shelf – a floating extension of Antarctica's land-based glaciers. On meeting the coastline, these ice streams continue flowing out over the ocean, melding together to form massive flat slabs of ice that float out over the ocean. The Ross Ice Shelf is the largest of these, covering an area of ocean around twice the size of New Zealand. And it is typically between 500 and 700 m thick at the point that it leaves the land. The ice gets thinner as it stretches northwards, partly because it's being melted away from...
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What to do with extraordinary sea ice conditions?

This year's local sea ice coverage is a bit different from 'usual'. Sea ice is the ice that forms when the air temperatures get so cold that the surface of the ocean freezes. This happens at both ends of the earth. But in the Southern Ocean, such a large area freezes that it effectively doubles the size of Antarctica each winter. This is huge, especially when one realises that Antarctica is already 50x the size of New Zealand! You can think of sea ice like a great big flat, white ship that is currently securely moored to the land. But as summer comes on, that 'ship' will break up and sail away, allowing us only a fixed window of time in which it is safe to do our science. Actually, we're using this to our advantage – before we head home, we'll be placing instruments out on the ice that will float north with it and transmit their position daily as they drift away from the land to circle around Antarctica. This will give us real-time information about how t...
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We’ve got the science underway!

On one previous occasion, I have arrived in Antarctica ahead of my cargo. However, this is the first time that I've headed out to the field camp while the bulk of our scientific cargo is still sitting in Christchurch. Moving large volumes of cargo south depends on flights of the US Air Force's C-17s between Christchurch and Phoenix Airfield (~30 mins drive across the ice shelf from McMurdo Station). These military aircraft are capable of shifting people (accommodated with sling seats or palleted airline seats) and/or large items of equipment (I've seen helicopters and D8 bulldozers rolled out of them previously). But they can only do so early or late in the summer season, when the weather is sufficiently cold that the packed snow runway can land them safely. So, the C-17 flights are the main 'airbridge' through September and October. However, this year only one C-17 was made available for Antarctic service, and it has had a few mechanical issues. So here we ar...
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