The first comprehensive study of snowfall across Antarctica provides vital information in the study of future sea-level rise.
Presenting this week (Monday 9 April 2018) at the European Geosciences Union (EGU) meeting in Vienna, an international team, led by British Antarctic Survey, describes how analysis of 79 ice cores collected from across Antarctica reveals a 10% increase in snowfall over the last 200 years. This is equivalent to 272 giga tonnes of water – double the volume of the Dead Sea.
Lead author and ice core scientist Dr Liz Thomas from British Antarctic Survey explains:
“There is an urgent need to understand the contribution of Antarctic ice to sea-level rise and we use a number of techniques to determine the balance between snowfall and ice loss. When ice loss is not replenished by snowfall then sea level rises. Satellite observations give us a picture going back around 20 years. Analysis of the ice core records allows us to reconstruct snowfall over several hundred years.
“Our new results show a significant change in the surface mass balance (from snowfall) during the twentieth century. The largest contribution is from the Antarctic Peninsula, where the annual average snowfall during the first decade of the 21st century is 10% higher than at the same period in the 19th century.”
The increases in snowfall do not contradict observations of glacial retreat and mass loss in regions of West Antarctica such as Pine Island and Thwaites Glacier, which are collectively contributing around 14% of global sea-level rise.
Dr Thomas continues:
“There is an international effort to create computer simulations of future sea-level rise in a warming world. It is complex and challenging for scientists to fully understand and interpret changes in the ice that we see happening today. We know that the two major influencers affecting change – the mass gain (from snowfall) and the mass loss (from melt) – are acting differently from one another. Our new findings take us a step towards improving our knowledge and understanding.”
Ends
Issued by the Press Office at British Antarctic Survey:
Athena Dinar, Senior PR & Communications Manager, British Antarctic Survey, tel: +44 (0)1223 221 441; mobile: +44 (0)7909 008516; email: amdi@bas.ac.uk
Layla Batchellier, Communications Officer, British Antarctic Survey, tel: +44 (0) 1223 221506; email: laytch@bas.ac.uk
Notes to Editors
Footage and stills of ice coring in Antarctica are available from the BAS ftp site as below: ftp://ftp.nerc-bas.ac.uk/pub/photo/Ice-Core-Antarctica/
To download individual files: do not use an FTP Client, simply open the above link with any standard web browser (Firefox, IE, Safari etc), right click on the filename and select ‘save target/link/file as’ to begin the download. NB for Mac users: if requested to login, simply click on to proceed
Regional Antarctic snow accumulation over the last 1000 years by Elizabeth R. Thomas, Melchioior van Wessem, Jason Roberts, Elisabeth Isaksson, Elisabeth Schlosser, Tyler J. Fudge, Paul Vallelonga, Brooke Medley, Jan Lenaerts, Nancy Bertler, Michiel R. van den Broeke, Daniel A. Dixon, Massimo Frezzotti, Barbara Stenni, Mark Curran and Alexey A. Ekaykin was published in the EGU journal Climate of the Past. See here: https://www.clim-past.net/13/1491/2017/cp-13-1491-2017.html
Dr Liz Thomas is presenting at EGU in Vienna on Monday 9 April. The oral presentation PIC spot 4 is on Monday at 08:50; viewing time 09:00-10:00 at PICO screen PICO04.11. Dr Thomas is also convening a session ‘Studying the climate of the last two millenia’ at 08:30 – 12:00 in Room F2 and will be available for interview in the Media Centre between 13:00 – 14:00. To arrange interviews on Monday please contact Dr Thomas on her mobile +44 (0) 7967 127295.
The Antarctic Ice Sheet (AIS) is the largest reservoir of fresh water on the planet and has the potential to raise sea level by about 58.3 metres if it melted completely (IPCC 2013). Even small changes in its volume could have significant impacts, not just on global sea level, but also on the wider hydrological cycle, atmospheric circulation, sea surface temperature, ocean salinity and thermohaline circulation.
In order to better constrain predictions of future contributions to global sea level, it is therefore of vital importance to gain a thorough understanding of past and present changes in Surface Mass Balance (SMB) and its relationship with the climate system.
Ice cores taken from central Antarctica and Greenland have revealed how the temperature and the greenhouse gases such as carbon dioxide and methane have varied over periods as long as 800,000 years.
British Antarctic Survey (BAS), an institute of the Natural Environment Research Council (NERC), delivers and enables world-leading interdisciplinary research in the Polar Regions. Its skilled science and support staff based in Cambridge, Antarctica and the Arctic, work together to deliver research that uses the Polar Regions to advance our understanding of Earth as a sustainable planet. Through its extensive logistic capability and know-how BAS facilitates access for the British and international science community to the UK polar research operation. Numerous national and international collaborations, combined with an excellent infrastructure help sustain a world leading position for the UK in Antarctic affairs. For more information visit www.bas.ac.uk
