Ritscher Flya Plateau, 60 km from Wasa, Antarctica, 23 December

Meet LISA, the Lightweight In Situ Analysis box. LISA is one of a kind – a laboratory in a box, built by our friend and collaborator Helle Kjær at PICE at the Niels Bohr Institute, part of the University of Copenhagen. LISA has been used quite a lot in Greenland, but iQ2300 is the first time she has ever been used in Antarctica.

Much of the work in Antarctica involves drilling snow and ice cores. These are used to reconstruct how much snow has fallen, whether there has been any melt, and – in the case of deep ice cores such as EPICA Dome C and Vostok – to reconstruct past climate change over hundreds of thousands of years. Usually, the cores are either measured fairly simply in the field (for temperature, density and to identify any ice layers) and then discarded, or they are transported – at great expense – back to laboratories around the world.

The clever thing about LISA is that she bridges the gap in between. She enables much more complex analysis of shallow snow and firn cores (firn is compacted, older snow on its way to becoming glacier ice) directly in the field, and makes it possible to spot interesting features while it is still possible to collect additional datasets. LISA also allows us to collect and process multiple cores in one spot so that we can identify local variability caused by snowdrifts and sastrugi – wind-shaped hard ridges and grooves – on the snow surface.

We hope LISA will help us understand how much snow falls in Dronning Maud Land, how much it varies from year to year, and what influence sea ice and far-field atmospheric processes have on snowfall rates. Snowfall is exceptionally difficult to measure and is one of our biggest uncertainties when we try to calculate the Antarctic mass balance and Antarctica’s response to a changing climate.

This week we deployed LISA at one of our selected field sites and carried out a really good field test of the system (thank goodness for satellite Wi-Fi to the rest of the world so that LISA’s creator could help with the usual troubleshooting). We produced some interesting data that is now in post-processing – both so that we can be more efficient next time we deploy the system, and to help us select new field sites for future deployments. Unfortunately, some of the more complex chemistry did not work, so we are using the Christmas break to make a few repairs and hope that next time we will come closer to a full house.

This is LISA’s first field deployment in Antarctica, and even if she did not reveal all of the snow’s secrets, it is still an achievement worth celebrating that we got half of it – and an interesting half, too.

We chose a coring site around 60 km from Wasa, so it was a slow snow-scooter trip up Plogbreen (“the plough glacier” – named after our neighbouring nunatak Plogen) and on to the flat plateau of Ritscher Flya at about 1,000 m elevation, where we were greeted by a beautiful halo and precipitation from a clear sky (also known as diamond dust). In fact, we nicknamed the site Diamond Dust because of the clear-sky precipitation on the first morning.

It was a fairly windy and snowy site, in a katabatic wind zone – thankfully not too strong on this trip – which was intentional, as one of the aims of our study is to investigate the effects of strong winds on snow accumulation. Katabatic means that cold, dense air flows downslope and creates a downward-directed wind. Since preparations for departure took most of the day (especially the chemistry mixtures for LISA), we headed out in the afternoon and then stayed overnight in these fantastic little living modules on skis.

The Swedish Polar Research Secretariat calls them arks, and they are really a very good solution to the problem of cold, wind, and trying to work in quite extreme conditions. Pulled by a snow scooter and with a stove inside for melting snow and heating, they are very cosy to sleep in. It makes a big difference to be able to warm up when, for example, you have been sitting in a snow pit at –15°C with a hefty wind chill on top and are covered in blowing snow…

We quickly got into a good working rhythm: Henrik did the coring, Clement logged, and Ninis and I assisted with the cores. Then it was time to get LISA going – and a very long and slightly frustrating day followed. Fortunately, by bedtime, and after rebuilding quite a lot of the internal tubing inside the box, we had LISA ready for work the next day.

n the picture you can see the LISA box with a melting ice core on top and the computer recording the data as it comes in. The pop-up fishing tent, which served as our field laboratory, was essential for working at this site in the cold winds. Without wind chill it was about –10°C outside. Preventing ice crystals from forming in the chemistry lines and reagents is also a concern, but having the heated arks really simplifies things.

I dug a snow pit – always one of my favourite activities. It is great to get your hands in the snow and really feel what is going on – and we identified some really intriguing layers that we have already started linking to other sites.

After two nights out, however, it was time to pack up and head back, three cores and a lot of data richer – for a shower, laundry, and a Christmas Eve day off, enjoying plenty of good food courtesy of our fantastic Swedish chef Raymond.

Text: Ruth Mottram, researcher at the Danish Meteorological Institute (DMI)