The impact of near-surface snow metamorphism on climate signals in Antarctica
WSL Institute for Snow and Avalanche Research SLF
Lay summary
Ice cores at Dome-C (Antarctica) offer exceptionally well-preserved long-term records of past climates due to the high elevation (3,233 metres above sea level), low temperatures (below -20°C in summer), and low precipitation (25 mm/year) at this location. Previous climate reconstructions from ice cores assumed that the climate signal initially stored in the precipitation is also stored in the surface snow and subsequently buried. However, recent studies found that post-depositional snow metamorphism processes, where the snow crystals change their size and shape over time, can significantly alter the isotopic signal and complicate the interpretation of ice core records.
This connection between snow metamorphism and the isotopic signal is part of the NIVO-3 project funded by the French Polar Institute (IPEV). As part of the NIVO-3 project, a snow metamorphism experiment led by WSL/SLF was carried out at Dome-C in 2023/2024 to study the effect of snow temperature conditions (governing metamorphism) on the isotope signal. To characterise the snow cover's strong horizontal and vertical microstructure variability, measurements of the 3D snow stratigraphy were performed with a new near-infrared photography instrument developed at WSL/SLF (SnowImager, www.snowimager.ch). Our results will provide unique insight into the evolution of the snow microstructure and isotopic composition at Dome-C, will contribute significantly towards an improved interpretation and reduce uncertainties of past climate signals in ice cores.
While on-site logistics and lodging were covered by IPEV through the participation of WSL/SLF in NIVO-3, the SPI Exploratory Grant allowed to cover additional logistical costs (travel, transport) for this expedition (www.slf.ch/en/news/antarctica-blog-part-1).
Details
| Regional focus | Antarctic |
| Location | Dome-C |
| Funded amount | 13,600 CHF |
| Project dates | 1st November 2023 – 28th February 2024 |
| Category | SPI Exploratory Grants |