East Antarctica, near Wasa, 2 January 2026

Our group – Work Package 9 (WP9) – carries out ground-based measurements to support the analysis of satellite data over East Antarctica, with a particular focus on the area around Wasa research station. We work both on the ice shelf (floating ice) and on land ice (ice resting on bedrock). Satellite observations allow us to study a wide range of ice-sheet properties – including features below the surface – and to cover much larger areas than is possible from the ground alone.

There are four of us in the team: Celia from the German Aerospace Center (DLR), Ian and Andrew from Stockholm University, and Mats from the Swedish Polar Research Secretariat. Our main task is to drill snow cores from the upper ~10 metres of the snowpack to better understand how satellite measurements relate to conditions on the ground. We primarily use radar satellites, which can penetrate into the snow – that is why we need to know what the snow looks like beneath the surface. We also use global navigation satellite systems (GNSS, often referred to as GPS) to measure snow-surface elevation, helping us understand how snow accumulation varies over time and across space.

It’s Tuesday today – not that we keep close track of the days. We work when we can, depending on weather, logistics and energy levels. So far, we’ve only missed a few days, and that was due to wind and snowfall (our energy levels are holding up!). Yesterday we returned from two nights on the Riiser-Larsen Ice Shelf. The ice shelf is roughly the size of Jämtland County, and we were probably the only four people out there. We travelled onto the shelf using four snowmobiles, towing two sledges and two “arks”. The arks are small caravan-like shelters used in northern Sweden for ice fishing in relative comfort – we use them as an alternative to tents. We also brought a tent for use as a toilet shelter. Everything we take out, we bring back. Everything.

Out on the ice shelf we drilled cores using our PICO auger. The PICO is a 1970s design developed by the U.S. Polar Ice Coring Office. Ours is old, but still working well. We core by hand and, as a well-drilled team (excuse the pun), we can extract a 10 m core profile in 2–3 hours. Each “core” is actually made up of multiple segments – we bring up around 21 segments to reach 10 metres. We then weigh the core (in shorter sections) and record the occurrence of ice layers and changes in snow grain size. These details help us understand how radar waves interact with the snow, allowing us to interpret our satellite imagery more accurately. The cores also preserve information about how the snow has changed over time – climate data, in other words.

A typical coring day starts with breakfast, followed by a snowmobile journey to a measurement site. We try to keep travel time below three hours to maximise time for data collection and reduce fatigue from driving. We stop along the way to make sure everyone is comfortable and to check progress. At the site, we begin by probing for crevasses – safety is paramount. Then we usually have a coffee. Drilling takes time: two of us drill while the other two measure and log the core segments. We write everything down in notebooks to ensure we have a hard copy. When we’re done, we either move on to the next site or head “home”. Home might be an ark, in which case we put water on to boil so we can have dinner. We heat up frozen meals prepared by our cook, Raymond – far better than trail food or other survival rations. With not much else to do, we chat, read and turn in early.

During our trip to the ice shelf, we drilled three cores in two days. One of the sites was also cored in 1989, and we hope to provide continuity with earlier research. Another site was measured in 2021/22 by Andrew and Ian, meaning we can track changes over time. We also carried out GNSS measurements at locations that satellites will overfly in the near future. After two nights – and after drilling the third core – we packed up and headed back. We made it to Wasa in time for a slightly late dinner (homemade pytt i panna). Tired, sunburnt and very hungry, we were grateful to take a shower after dinner and sleep in a bunk.

Today, Tuesday, was a rest day. Just kidding – we headed out again on snowmobiles to another site 30 km from Wasa. This was Celia’s idea! Here we wanted to look for snowpack differences that might help explain patterns we see in radar satellite images from Sentinel-1. Sentinel-1 is part of the European Copernicus programme and is crucial to our work. Tomorrow, the forecast looks poor, so we may only manage a half day in the field. The German satellite EnMAP flew over yesterday and today, and we want to measure snow grain properties before the weather changes. Then we can rest. Maybe.

Text: Ian Brown, Stockholm University