Wasa, Antarctica, 2026-01-27

It was a very bumpy snowmobile trip, the one we just returned from! We headed south-east from Wasa towards Heimefrontfjella five days ago. Our targets were two locations on a vast icy plateau spanning elevations from 850 to 1,200 metres above sea level. It took ages to cover the 150 km, as the wind had created beautiful frozen waves – sastrugi, sometimes half a metre high. Along parts of the route, where the sastrugi were especially well developed, we only bumped forward at 12 km per hour.

One 20-metre-long core was drilled in no time by the now very experienced coring team, this time without any mishaps (such as dropping extension pins into the hole). The chopping up, bagging and weighing of 5 cm sections took much longer. When it is windy and cold – a typical condition – we do this inside a pop-up tent. In total, 400 snow samples were transported back to Wasa Station for melting. An additional core was wrapped and transported to the LISA box for analysis (see previous post).

The meltwater will be analysed at the Stable Isotope Laboratory at Stockholm University. We use the fact that the ratio between oxygen-16 (light) and oxygen-18 (heavy) in snow shifts due to seasonal temperature changes. (https://science.nasa.gov/earth/earth-observatory/paleoclimatology-the-oxygen-balance/) Using a timescale based on oxygen-isotope swings, we can determine how much snow (and how much water!) accumulated each season. The results are needed as input to the ice-sheet and climate models we use to predict how global warming affects the Antarctic ice sheet and the pace of sea-level rise.

Staying in the ark is really cosy – if the stove works! The first evening was so chilly that even the kerosene was too cold to burn. After some fixing by our super-support crew, it lit up and we could warm our hands, feet and dinner – pasta Bolognese – vacuum-packed by our Wasa chef.

The midnight sun still shines, but by the time we leave Wasa and Antarctica next week it will sink below the horizon. Autumn is approaching, and we can feel the drop in temperature – this morning everyone put on an extra layer of wool.

Text: Ninis Rosqvist, Stockholm University