On December 12, Sibylle Boxho - a doctoral student at the G-Time and BGEOSYS laboratories, Faculty of Science, Free University of Brussels - sets sail for the Princess Elisabeth Station in Antarctica. She will remain there for 2 months (return scheduled for February 10, 2024), accompanied for this project by a researcher from UGent. Aged 25, this is her first mission to Antarctica.
The mission is twofold: to install a new sampling site and to collect snow samples.
First part: installation of a sampling site
The new snow sampling site was designed and built in close collaboration with researchers from the BEAMS department, Ecole Polytechnique de Bruxelles - Axel Dero, Michel Osée, Christophe Reyntiens. It consists of a circular tray topped and covered by a cone. The tray can hold 4 x 2-liter containers, each corresponding to 3 months’ snow harvesting. The motorized cone is fitted with a single orifice which is aligned successively with each of the containers over the course of the year. A microcontroller controls the rotation of the cone every 3 months, and ensures that the system doesn’t freeze thanks to micro-movements programmed to take place once a day.It will enable snow samples to be collected and stored all year round - without human intervention, whereas previously they were collected only once a year, during a mission. This continuous collection will make it possible to monitor the seasonal evolution of snow deposits.
The sampling site should be set up near the coast, around 200km from the Princess Elisabeth Station.
Second stage: collecting snow samples
Sibylle Boxho will collect snow samples in two trenches - about two meters deep to collect the different layers of snow accumulation over the seasons of a year - and surface samples.Back in Belgium with these samples, the researcher will extract the rock dust in the laboratory and carry out various measurements, including rare earth element (REE) analysis.
In concrete terms, the REEs are like an identity card for this dust: these REE elements measured in both snow dust and rocks enable us to understand the proportion of dust arriving in Antarctica from a sometimes very distant zone, such as Africa. This will enable researchers to understand atmospheric circulations in the southern hemisphere over the course of a year and each season.
The environmental and climatic impact of dust on snow-covered surfaces will also be studied. For example, the addition of dust reduces the area’s albedo (the proportion of solar radiation reflected back into the atmosphere), thereby accelerating ice melt in the area. Another example is the detection of anthropogenic dust deposits, to better understand the impact of human activity on the continent of Antarctica, still considered "virgin".
In short, the rock dust in these snow samples will provide scientists with the keys to a better understanding of atmospheric circulations in the southern hemisphere, as well as a better anticipation of the impact of this dust and its implication in a potential acceleration of climate change in Antarctica.
https://actus.ulb.be/fr/actus/recherche/mission-en-antarctique-des-echantillons-de-neige-pour-comprendre-le-climat
